Yearly Archive October 10, 2020

Internal grinder processing

The internal grinder is very common in mold factories and hardware processing plants, and has become the common equipment of the majority of mechanical industry technicians. The selection of abrasive is very important for large grinding machine processing in the operation of internal grinder.

Characteristics of CNC system for internal grinder

Portability: the functional software of the system is independent of the equipment, and various functional modules run in different control systems, that is, they can run on the hardware platforms provided by different suppliers;

Scalability: the function and scale of CNC system of internal grinder can be flexibly set and modified easily. The size of the control system (hardware or software modules) can be increased or decreased according to the specific application;

Expansibility: users or secondary developers of CNC system of internal grinder can effectively integrate their own software into the NC system to form their own special system. The increase or decrease of functions only requires the loading and unloading of function modules;

Interchangeability: through standardized interface, computer gong processing, mechanical parts processing, Dongguan CNC machining center, Dongguan high-speed computer gong processing communication and interaction mechanism, different functional modules can run on the system platform with standard application program interface, and obtain equal mutual operation ability and coordinate work.

Interchangeability: the selection of hardware modules and functional software constituting the system is not controlled by a single supplier, and can be replaced with each other according to the requirements of function, reliability and performance, without affecting the coordinated operation of the whole system;

The harder the grinding roller surface of the internal grinder is, the softer the hardness of the grinding wheel should be selected.

(1) If the grinding wheel is obviously blocked (hard) or dirty, the passivated sand particles are not easy to fall off, the grinding wheel is easy to adhere to the grinding debris, and the grinding roller surface appears burn and scuffing, it indicates that the selected grinding wheel is too hard, and the following measures can be taken to improve it:

A. Reduce the linear speed of grinding wheel;

B. Increase the roller speed.

If the grinding effect is not obvious after the above measures are taken, it means that the grinding wheel is too hard, so the soft grinding wheel should be selected.

  1. Selection of bond for grinding wheel of internal grinder

Except resin bonded grinding wheel, ceramic grinding wheel is better for other grinding types of roller surface.

(2) If the grinding wheel is worn too fast, it means that the grinding wheel selected for the specific processing roll is too soft. The following improvement measures can be taken:

A. Increase the linear speed of grinding wheel;

B. The longitudinal feed rate of the carriage is increased to 2 / 3-3 / 4 of the width of the grinding wheel;

C. Reduce the roll speed.

If no obvious grinding effect has been obtained after the above measures are taken, it means that the grinding wheel is too soft and not suitable for use, and a harder grinding wheel should be selected.

Machinability includes formability and cutting property. Because the formability is related to the state, the strength range of various states should be considered after selecting the grade of aluminum alloy. Generally, the material with high strength is not easy to form. If bending, stretching, deep drawing and other forming processes are needed, the formability of the fully annealed material is the best, while the formability of the heat-treated state is the worst. The machinability of aluminum alloy is closely related to the alloy composition. Generally, the machinability of aluminum alloy with higher strength is better than that of aluminum alloy with low strength. The machinability of aluminum alloy is an important factor to be considered for the products that need to be machined, such as dies and mechanical parts.

Architectural aluminum is a kind of decorative structural materials. In order to improve its decorative effect, enhance its corrosion resistance and extend its service life, except for some cases, it has to go through surface treatment.

Many customers are very concerned about the hardness when buying aluminum products. The hardness is directly related to the chemical composition of the alloy. Secondly, different states also have great influence. In terms of the highest hardness that can be achieved, 7 series, 2 series, 4 series, 6 series, 5 series, 3 series and 1 Series decrease in turn. Therefore, surface treatment has become an essential and important process in the production of architectural aluminum profiles. There are many methods of surface treatment for computer gongs, and corresponding surface treatment methods can be adopted according to different uses of materials. The commonly used commercial surface treatment methods are: Anodizing coloring, electrostatic powder spraying, fluorocarbon spraying, electrophoretic painting, chemical coloring, water ripple treatment, etc.

Strength is an important factor that must be considered in product design, especially when aluminum alloy components are used as structural parts, appropriate alloy should be selected according to the pressure they bear. The strength of pure aluminum processed by computer gong processing, mechanical parts processing, Dongguan CNC machining center, Dongguan high-speed computer gong processing is the lowest, while the strength of 2-Series and 7-series heat-treated alloys is the highest. There is a positive correlation between hardness and strength.

Corrosion resistance includes chemical corrosion resistance, electrochemical corrosion resistance and stress corrosion resistance. Generally speaking, the corrosion resistance of 1 series pure aluminum is the best, 5 series is good, followed by 3 series and 6 series, and 2 series and 7 series are poor. The selection principle of corrosion resistance should be determined according to the application situation. When high strength alloy is used in corrosive environment, it is necessary to use various composite materials for corrosion protection.

Processing by material classification: aluminum alloy, hard aluminum, aluminum oxide, copper, brass, bronze, red copper, titanium, iron, aluminum parts, imported domestic carbon steel, manganese steel, alloy steel, tool steel, high speed steel, 303, 304, 316, 303, 400 stainless steel, saigang, ABS acrylic (PMMA), PC, POM Non standard precision machining of PVC, PP, nylon, bakelite, plastic, Teflon, epoxy board, plastic, etc

Mechanical parts processing – Painting

Over the past 30 years since the reform and opening up, the coating industry has made great progress in self-improvement and development in order to meet the development needs of various departments of the national economy. Products, quality, variety, quantity and technical equipment level have been greatly improved. In particular, through the introduction of technology and cooperation with foreign investors, the technical level and ability of the industry have been improved.

“2013-2017 China coating industry market demand forecast and strategic investment planning analysis report” shows that at present, the domestic coating industry in coating materials, coating technology and equipment, has basically met the needs of household appliances, machine tools, machinery, furniture, construction and other industries, and has made outstanding contributions to the development of the national economy, but the domestic coating technology is similar to the foreign advanced technology There is still a big gap between the two, which is mainly reflected in the industries with higher requirements for coating technology, such as car coating, which can not fully meet the requirements. At present, the domestic car coating technology and equipment are still mainly foreign technology and equipment.

In addition, domestic coating enterprises have made a lot of efforts in technical innovation, and have made great achievements. However, it still needs independent innovation. The direction and goal of the future development of the coating industry is to further meet the needs of the continuous development of the national economy, mainly to reduce pollution, energy conservation and emission reduction, improve the process, improve the decorative, protective and functional properties of coatings, as well as the generalization, serialization and automation of coating equipment. The so-called coating refers to covering metal and non-metallic surfaces with protective or decorative layers. With the development of industrial technology, it goes deep into many fields of national economy. The development of China’s coating production line has experienced the development process from manual production line to automatic production line. The painting process in China can be simply summarized as: pretreatment → spraying → drying or curing → three wastes treatment. China’s painting industry really originated after the introduction of Soviet technology in the 1950s. Since the 1960s, due to the development of light industry, there have been mechanized production lines and automatic production lines in the bicycle manufacturing industry, as well as the program-controlled assembly lines formed on the basis of the original trough production line and the program-controlled car, which are mainly in Shanghai and Tianjin. During this period, the main task of China’s coating industry was mainly anticorrosion. However, with the development of China’s economy and the development of foreign painting technology, through the introduction of technology and the exchange of foreign technology, China’s coating technology began to develop rapidly. In the aspect of coating automation production, the popularization and application of electrostatic spraying and electrophoretic painting technology, and the development and promotion of powder spraying technology, especially in China’s home appliance industry, household hardware, steel furniture, aluminum With the rapid development of components, electrical products, automobile industry and other fields, the coating industry has made obvious progress.

2、 Coating production spare parts – coating equipment:

  1. Through shot blasting chamber

The through shot blasting chamber is composed of cleaning chamber body, shot blasting machine, shot circulation system, ventilation and dust removal system, bottom foundation and electrical control system. Non standard design of different sizes can be carried out according to different specifications of workpieces, and finalizing equipment can also be selected.

Through shot blasting chamber is suitable for cleaning and strengthening the surface of structural parts of construction machinery, forging and casting, and high-speed computer gong processing, so as to obtain a smooth surface with certain roughness, increase the adhesion of coating film and improve the anti-corrosion effect of workpiece. When the workpiece enters the shot blasting chamber, the shot blasting machine driven by the motor will throw high-speed projectiles centrifugally, which will strongly impact the rust and oxide scale on the surface of the workpiece. The surface quality of the workpiece can reach the standard of SA2 ~ Sa2.5.

  1. Water spinning spray booth

Water spinning spray booth is also called hydraulic spinning spray booth. This chamber adopts the gas laminar flow suppression method to prevent the paint mist from spreading, and uses the hydraulic spinning pipe to filter the paint mist. It is a relatively complete paint spraying room in technology at present.

The water spinning spray painting room is composed of a chamber body, an electric door, a paint mist filtering device, an air conditioning air supply device and an exhaust device. The lighting device is installed on both sides of the room, and the illumination is above 500 lux, which can be controlled in groups. Combustible gas concentration detection and alarm devices are installed indoors. The paint mist filtering device is composed of washing plate, hydraulic spinning device, underground water tank and exhaust device. The results show that the removal rate of paint mist is more than 98%. The air supply device is the main component to make the gas form laminar flow. After being filtered and heated, the air sent into the air supply room is evenly sent to the room from the air supply ceiling, so that the indoor wind speed is even. When there is no workpiece, the vertical wind speed can reach (0.35 ~ 0.4) m · s – 1; The exhaust device uses a fan to filter the gas containing paint mist in the chamber through a hydraulic spinning pipe, and then discharges it from the sink and the washing plate.

  1. Hot air drying room

The drying method is hot air circulation convection mode, its biggest advantage is that the baking is uniform, especially suitable for the construction machinery parts with large heat capacity. Heating heat sources include steam, electricity, light diesel, natural gas, liquefied petroleum gas, etc. If conditions permit, LPG shall be preferred. It is a kind of clean and efficient energy. The biggest advantage is that the cost of production and operation is only 35% – 40% of the cost of electricity.

  1. Conveying system

For construction machinery components (structural parts), the use of self-propelled electric hoist is an effective choice.

The conveying system of self-propelled electric hoist is composed of gantry column, bearing rail, sliding conductor rail, collector, loading car, electric hoist and central control cabinet controlled by PC.

The system integrates mechanical, electronic, computer, automatic

Selection of milling cutter type

(1) Selection of milling cutter type

According to the geometry of the parts to be processed, the types of cutting tools are selected as follows:

1) When machining curved surface parts, in order to ensure that the cutting edge of the cutter is tangent to the machining contour at the cutting point, the high-speed computer gong machining is used to avoid the interference between the cutting edge and the workpiece contour. Generally, ball end cutter is used for rough machining, and four edge milling cutter is used for semi finishing and finishing machining, as shown in Fig. 4.

2) When milling large plane: in order to improve the production efficiency and surface roughness, insert type disc milling cutter is generally used, as shown in Fig. 5.

3) When milling small plane or step surface, general milling cutter is generally used, as shown in Fig. 6.

4) In order to ensure the accuracy of keyway milling, use the cutter as shown in Figure 7.

5) During hole processing, drill bit, boring cutter and other hole processing tools can be used

Milling cutter is generally composed of blade, positioning element, clamping element and cutter body. There are many kinds of positioning and clamping methods for the blade on the cutter body, and the structure of the positioning element of the blade has different types. Therefore, there are many kinds of structure forms and classification methods of milling cutter. When selecting, it can be mainly according to the arrangement of blades. The arrangement of blades can be divided into two categories: flat mounting structure and vertical mounting structure.

Flat structure (radial arrangement of blades)

The flat structure milling cutter (as shown in Fig. 9) has a good structure and is easy to process. It can also use a non hole blade (the blade price is low and can be reground). Due to the need for clamping elements, a part of the blade is covered, the chip holding space is small, and the cemented carbide section in the direction of cutting force is small, so the flat structure milling cutter is generally used for light and medium milling.

Vertical installation structure (blade tangential arrangement)

The blade of end mounted structure milling cutter (as shown in FIG. 10) is fixed on the cutter groove with only one screw, which is simple in structure and convenient in rotation. Although there are few tool parts, it is difficult to process the cutter body, so it is necessary to process it with five coordinate machining center. Since the blade is clamped by cutting force, the clamping force increases with the increase of cutting force, so the clamping element can be omitted and the chip holding space is increased. Because the blade is installed in tangential direction, the section of cemented carbide in the direction of cutting force is large, so it can be used for large cutting depth and large cutting distance. This kind of milling cutter is suitable for heavy and medium milling.

The angle of milling cutter includes front angle, back angle, main deflection angle, auxiliary deflection angle, edge inclination angle, etc. In order to meet the different processing needs, there are a variety of angle combination types. The main deflection angle and rake angle are the most important in the processing of high-speed computer gongs.

Main deflection angle KR

The main deflection angle is the angle between the cutting edge and the cutting plane, as shown in FIG. 11. The main deflection angles of milling cutter are 90 °, 88 °, 75 °, 70 °, 60 ° and 45 ° etc.

The main deflection angle has a great influence on the radial cutting force and cutting depth. The size of radial cutting force directly affects the cutting power and anti vibration performance of cutting tools. The smaller the main deflection angle of the milling cutter is, the smaller the radial cutting force is, the better the vibration resistance is, but the cutting depth is also reduced.

The main deflection angle of 90 ° is selected when milling the plane with shoulder, but it is not used for pure plane machining. This kind of tool has good versatility (not only can process step surface, but also can process plane), so it can be selected in single piece and small batch processing. Because the radial cutting force of this kind of cutting tool is equal to the cutting force, the feed resistance is large, and it is easy to vibrate. When machining the plane with shoulder, the milling cutter with 88 ° main deflection angle can also be selected. Compared with the milling cutter with 90 ° main deflection angle, its cutting performance is improved to some extent.

The main deflection angle of 60 ° to 75 ° is suitable for rough machining of plane milling. Due to the obvious reduction of radial cutting force (especially at 60 degrees), its vibration resistance is greatly improved, and the cutting is smooth and light. Therefore, it should be preferred in plane machining. 75 ° main deflection angle milling cutter is a general-purpose tool with wide application range; 60 ° main deflection angle milling cutter is mainly used for rough milling and semi finishing milling on boring and milling machines and machining centers.

The radial cutting force of this kind of milling cutter with 45 ° main deflection angle is greatly reduced, which is approximately equal to the axial cutting force. The cutting load is distributed on the longer cutting edge, and has good vibration resistance. It is suitable for the machining occasions with longer spindle overhang of boring and milling machine. When machining plane with this kind of cutting tool, the damage rate of blade is low and the durability is high; when machining iron castings, the edge of the workpiece is not easy to break.

Anterior angle γ

The rake angle of milling cutter can be divided into radial rake angle γ F and axial rake angle γ P. the radial rake angle γ f mainly affects the cutting power; the axial rake angle γ P affects the chip formation and the direction of axial force. When γ P is positive, the chip will fly away from the machining surface. The discrimination between the positive and negative radial forward angle γ F and the axial forward angle γ P is shown in FIG. 12.

The common combination forms of front angle are as follows:

The milling cutter with double negative rake angle and double negative rake angle usually adopts square (or rectangular) blade without back angle. The cutter has many cutting edges (generally 8), high strength and good impact resistance, which is suitable for rough machining of cast steel and cast iron. Because the chip shrinkage ratio is large, it needs a large cutting force, so the machine tool has higher power and higher rigidity. Because the forward angle of the shaft is negative, the chip can not flow out automatically. When cutting ductile materials, chip accretion and tool vibration are easy to occur.

It is suggested that the double negative rake angle milling cutter should be preferred in order to make full use of and save the blade. When double positive rake angle milling cutter is used to produce chipping edge (i.e. large impact load), the double negative rake angle milling cutter should also be preferred when the machine tool allows.

The milling cutter with double positive rake angle and double positive rake angle adopts a blade with back angle. The wedge angle of the cutter is small

Computer gong processing – Characteristics and routes

In fact, computer gong is a CNC milling machine. In Guangzhou, Zhejiang and Shanghai, a person named “CNC machining center” is an automatic machine tool with program control system. (CNC machine tool) is a short name for computer numerical control, and it is an automatic machine tool controlled by program. The control system can logically process the program with control code or other symbol instructions, decode it by computer, so that the machine tool can act and process parts. The rough blank is processed into semi-finished finished parts by cutting tools.

CNC machining is the machining of CNC machining, which is made by means of CNC tools. CNC index control machine tool is programmed and controlled by NC machining language, usually G code. NC machining G code language tells the NC machine tool which Cartesian position coordinates to use, and control the feed speed and spindle speed of the tool, as well as tool converter, coolant and other functions. NC machining has a great advantage over manual machining. High speed computer gong processing, such as parts produced by NC machining, is very accurate and repeatable; NC machining can produce parts with complex shape which cannot be completed by manual machining. CNC machining technology has been widely spread, most machining workshops have the ability of NC machining. The most common NC machining methods in typical machining workshops are NC milling, CNC car and CNC EDM wire cutting (EDM). The tool for NC milling is called CNC milling machine or CNC machining center. The lathe for NC turning is called the CNC lathe center. The G code of NC machining can be programmed manually, but the machining workshop usually uses cam (Computer Aided Manufacturing) software to read CAD (CAD) files automatically and generate G code program to control the NC machine tool. The leading CNC machine brands are Hass, DMG (Deckel MAHO gildemester), Mazak, Mori Seiki, fadal and wasino.

2、 The route of computer gong processing:

The feed machining route of CNC lathe refers to the path that the tool moves from the point of alignment (or fixed origin of machine tool) until it returns to the point and ends the machining procedure, including the path of cutting and the path of cutting tool cutting and cutting out.

The feed route of finishing is basically carried out in the order of the outline of parts. Therefore, the key to determine the feed route is to determine the feed route of rough machining and empty stroke.

In the NC lathe processing, the determination of the processing route should follow the following principles.

① The accuracy and surface roughness of the workpiece to be processed shall be guaranteed.

② The shortest processing route, reducing the time of empty travel and improving the processing efficiency.

③ The work of numerical calculation and the processing procedure are simplified as much as possible.

④ For some reuse programs, subroutines should be used.

Besides the characteristics of ordinary milling machine, NC milling has the following characteristics:

  1. The parts processing is adaptable and flexible, and can process parts with complex outline or difficult to control size, such as mold parts and shell parts;
  2. It can process parts that can not be processed or difficult to process by common machine tools, such as complex curve parts described by mathematical model and 3D space surface parts;
  3. The parts that need to be processed by multiple processes after one clamping and positioning are processed;
  4. The high precision and reliable quality of the NC device are generally 0.001mm, and the high precision CNC system can reach 0.1 μ M. in addition, the operation error of the operators is avoided;
  5. The production automation is high, which can reduce the labor intensity of the operator. It is conducive to the automation of production management;
  6. The production efficiency is high, and the special process equipment such as special fixture is not required for CNC milling machine. When replacing workpieces, high-speed computer gong processing only needs to call the processing program, clamping tool and adjusting tool data stored in the NC device, thus greatly shortens the production cycle. Secondly, CNC milling machine has the functions of milling machine, boring machine and drilling machine, which makes the working procedure highly concentrated and greatly improves the production efficiency. In addition, the spindle speed and feed speed of CNC milling machine are stepless, so it is helpful to choose the best cutting amount.

2、 System classification of computer gongs processed by Shenzhen gongs:

① Cooling system. The cooling system of the machine tool is composed of cooling pump, water outlet pipe, return pipe, switch and nozzle. The cooling pump is installed in the inner cavity of the machine base. The cooling pump pumps the cutting fluid from the storage tank in the base to the outlet pipe, and then ejects through the nozzle to cool the cutting area.

② Lubrication system and method. Lubrication system is composed of manual oil donation pump, oil distributor, throttle valve, oil pipe, etc. The machine tool adopts periodic lubrication method, uses the manual lubrication oil pump, through the oil distributor to lubricate the spindle sleeve, the longitudinal and horizontal guide rail and the three-way ball screw, so as to improve the service life of the machine tool.

From the characteristics of digital control technology, because the servo motor is used in CNC machine tool, it should

Mold processing design knowledge

  1. The mold industry is the mother of industry. In terms of this year’s financial crisis, the mold industry is one of the earliest industries to recover. Therefore, it is very important to learn the mold well. However, due to the variability and uncertainty of mold materials and shapes, it is very difficult for us to learn mold well. Therefore, I will collect and sort out this 10 It’s classic. It’s worth collecting and reading. I’m sure you’ll appreciate my recommendation. I don’t need to communicate with UG, but you are welcome to communicate with me in the industry..
  2. Common shrinkage rate of plastic materials?

A: (see plastic materials) Click for information

  1. Common defects in plastic parts?

Answer: lack of glue, Cape, bubble, shrinkage, weld mark, black spot, bubble, stripe, warpage, delamination, peeling, etc

  1. Common plastic mold steel?

A: (see die steel)

  1. What kind of steel is used for high mirror polishing?

Answer: commonly used high hardness heat treatment steel, such as SKD61, 8407, S136 and so on!

  1. The role of mapping key?

Answer: simplify operation steps, reduce labor intensity, improve work efficiency!

  1. What’s the difference between mirror and mirror?

A: mirror body refers to the whole mirror image, and the mirror feature refers to local mirror image or single feature image!

  1. How to hide each other in UG?

Answer: Ctrl + B and Ctrl + Shift + B

  1. Is there a local bias function in UG?

A: Yes

  1. Does UG have symmetrical constraint function in sketching?

A: none

  1. What is 2D? What is 3D?

A: D is the prefix of dimension, 2D refers to two-dimensional plane, and 3D refers to three-dimensional space. In the mold part, 2D usually refers to plan drawing, i.e. CAD drawing; 3D usually refers to solid drawing, i.e. Pro / E, UG or other 3D software drawing files.

  1. What is the default accuracy of Pro / E? What is the default accuracy of UG?

A: the default accuracy of Pro / E is 0.0012mm, and that of UG is 0.0254mm

  1. What is the default word height of CAD?

Answer: the default word height of CAD is 2.5mm.

  1. Where is the text file of CAD?

Answer: the text file of CAD is placed in the fonts folder under the root directory of CAD.

  1. Does Pro / E have auto save function like CAD?

A: Pro / E has no auto save function

  1. What is touch through? What is penetration?

A: the joint surface of male and female mold parallel to pl surface is called impact through surface; the joint surface of male and female mold that is not parallel to pl surface is called interpenetrating surface!

  1. The relationship between sliver and silk?

A: both sliver and silk are units of length. In Taiwan, 1 = 0.01mm; in Hong Kong, 1 = 0.01mm, so 1 = 1

  1. What is pillow position?

Answer: the edge of shell plastic parts often has a gap, which is used to install various accessories

  1. What is a crater?

A: the mold crater is the shape similar to the volcano eruption reflected on the mold of the root of boos column.

  1. What do you mean?

A: ah, it’s Mo Ren, a Hong Kong idiom

  1. What is tiger mouth?

A: Tiger mouth, also known as tube position, is used to limit the part.

  1. What is ranking?

Answer: the product layout on the mold is called placement.

  1. What is glue position?

Answer: the cavity of the product on the mold is called glue position.

  1. What is bone position?

A: the tendon on the product is called bone position.

  1. What is column position?

Answer: boss column on the product is called column position.

  1. What is virtual position?

Answer: the gap on the mold is called virtual position.

  1. What is buckle?

Answer: the hook used for product connection is called buckle position.

  1. What is spark pattern?

After the spark machining is called spark striation.

  1. What is PL plane?

Answer: PL is the abbreviation of parting panel. PL is also called parting surface, which refers to the part of male mold and female mold in contact when the mold is closed.

  1. What is a computer gong?

Answer: general name of CNC milling machine and machining center

  1. What is a copper worker?

Answer: EDM usually uses copper material which is easy to process as discharge electrode, which is called copper work, also known as electrode. Copper workers are generally divided into roughs, roughers and young workers. Young workers are also called Seiko

  1. What is EDM?

A: an electric spark is a self-excited discharge. There is a high voltage between the two electrodes before discharge. When the two electrodes are close, the dielectric between them is broken down, and then spark discharge occurs. With the breakdown process of Dongguan high-speed computer gong machining, the resistance between the two electrodes decreases sharply, and the voltage between the two poles also decreases sharply. The spark channel must be extinguished in time after a short time (usually 10-7-10-3s), so that the machining of mechanical parts can maintain the “cold pole” characteristics of spark discharge (that is, the heat energy converted by the channel energy can not be transmitted to the depth of the electrode), so that the channel energy can act on a very small range. Due to the effect of channel energy, the electrode can be corroded locally. Using the corrosion phenomenon produced by spark discharge to process the size of materials is called EDM.

  1. What is the spark bit?

A: in the process of discharge, the discharge gap between copper and steel is called spark position. The spark position of rougher is generally 10 to 50, and that of young worker is 5 to 15

  1. What is the material level?

A: the wall thickness of plastic products is also called meat thickness.

  1. What is the original stay?

Answer: willing body retention is relative to cutting and inserting parts. Original body retention refers to a whole piece of steel material for processing embryo, which is processed together when processing

  1. What are weld lines?

A: the line formed by the meeting of two strands of plastic is called weld line.

  1. What is a jet?

A: the plastic from the inlet into the cavity after the formation of bending fold snake like flow marks, known as jet flow.

  1. What is LKM

Computer gong processing mold

  1. The height of slide guide rail shall be at least 1 / 3 of that of slide block to ensure the stability and smooth sliding of sliding block.
  2. Attention should be paid to the opening of lubricating groove where there is sliding friction. In order to prevent the outflow of lubricating oil, the groove should not be opened into “open type”, but should be “closed type”. Generally, the annular oil storage tank can be directly milled on the milling machine with a single cutter.
  3. For the cavity of fixed mold core, the small mold is generally cut by line cutting, which can improve the precision of the mold; while the mold cavity of the larger mold is generally processed in the form of milling, pay attention to its perpendicularity during processing, and in order to prevent the mold core from not in place during assembly, the milling depth should be 0.2mm around the mold frame, and the hole position should be pre drilled on the mold frame at the corner, which will form void avoidance after milling. Prevent the interference of the assembly die (chamfering can also be done on the die).
  4. The angle of 1 ° should be added to the interpenetration between the insert and the mold, between the mold core and the mold core, and between the mold core and the mold frame, so as to prevent collision and injury during assembly.
  5. The length tolerance and size tolerance of the insertion part are -0.02, -0.10 and + 0.02 respectively.
  6. The tolerance from the bottom of the c-angle to the c-angle is + 0.01 to prevent the burring.
  7. The main part of the body mould is made of NAK80 material, and the material of skh9 and SKH51 (material treatment: nitriding treatment is also allowed), and Viking material can be used if necessary.
  8. After drawing the parts, the position and size of the slider should be determined first to prevent interference and insufficient strength, and then the mold kernel size method should be determined.
  9. The tolerance of the size of the insert is – 0.01, and the tolerance of the hole in the mold is + 0. 01 (transition fit).
  10. The sharp corner of wire cut square hole on the mold core is excessive with r0.20, and the corresponding entry part is also r0.20, so as to influence the wire diameter during wire cutting, and prevent the sharp corner part from abrasion and edge overflow.
  11. The small pit size corresponding to the positioning ball (wave bead) is generally conical hole with bottom diameter of φ 3 and angle of 90 ° to 120 °.
  12. The draft angle of the fixed side should be greater than that of the movable side. The high-speed computer gongs can be used to process the mold leaving on the movable side. Moreover, it can prevent the parts from deformation, especially for the parts with thin wall and easy deformation in length, and the uneven pulling force on the fixed side will easily cause the parts to warp or stay on the fixed side.
  13. For the parts with large side core pulling force and strict part precision requirements, the secondary core pulling structure should be adopted.
  14. The slope of inclined tip + 2 ° = the slope of hold down block (generally 18 ° or 20 ° or 22 °)
  15. When assembling molds, the following habits should be formed:

a. Clean the surface of mold core, cavity, runner, runner plate and parting surface with air gun.

b. Before assembly, polish the surface of mold core, mold cavity, insert and parting surface with oilstone to facilitate smooth assembly.

c. Pay attention to the angle cleaning to prevent interference and bruise.

d. Before assembly, we should consider how to carry out the following work.

  1. The side pressing block of large mold core should be designed to be locked and the bottom should be 0.5-1.0mm below the parting surface to prevent interference.
  2. The shrinkage rate of PC + GF20 is 3 / 1000, and the shrinkage efficiency in the direction of material flow with GF is less than that in the direction of vertical material flow, which is different from other materials.
  3. The contraction rate of POM was normal 20 / 1000, but sometimes it was 30 / 1000.
  4. In order to prevent the parts from being scratched by the latent gate when the part is ejected, a wedge-shaped block is added 2-4mm away from the latent gate. The height of the wedge is about half of the runner, and the included angle is 10 ° on one side. The gate will be broken when ejected.
  5. The main channel pulling well adopts an inverted cone with a depth of 8-10 mm, an included angle of 10 ° on one side, and a top diameter of a wide flow channel. The advantage of this method is that it can prevent the pulling material from one side grinding into a wedge shape from hooking the flow channel during ejection, resulting in poor parting.

There are two kinds of opening and closing devices: 1. Made of rubber, the deformation is adjusted by the central screw to adjust the tension. 2. Made of spring steel. Their functions are: delay the opening time of movable side and fixed side, apply to small nozzle mold (three plate mold) or apply to secondary ejection system.

  1. In order to ensure whether the ejector pin and inclined pin of the mold are reset, some molds are equipped with early return mechanism (female is installed on 108 plate, male is installed on 102 plate, male is similar to thimble, the bottom is blocked with headless screw, and two are generally arranged) or microswitch (between 108 and 109 boards [power mounting element]).
  2. Considering the screw length of the injection molding machine when clamping the mold, it is necessary to pay attention to the thickness of the upper and lower fixing plates (generally about 40mm). If necessary, the four corners should be milled lower. At the same time, in order to improve the safety, four bolt holes can be drilled on the upper and lower fixed plates according to the position of the upper holes of the injection molding machine.
  3. The forming end of the oblique pin has a straight face, which is generally 4-6mm long. In order to slide the inclined pin between 107 and 108 plates during ejection, an R angle of 0.5mm-1mm should be poured at the bottom.
  4. For the appearance that needs to be bitten, the degree of biting should be considered in the design of draft angle, so as to avoid the appearance strain. For some protruding parts, the cross-section will become larger after biting, so the single side should be 0.02-0.03 smaller in actual processing.
  5. Considering that the mold closing between the fixed side and the movable side will result in break, the fixed side is 0.03-0.05 smaller than that of the movable side.
  6. In the mould with sliding block, sometimes it is necessary to set oil groove on the inclined surface of the sliding block and the pressing block; in addition, if the forming is not affected, the processing efficiency of opening oil groove on the upper surface of the template is higher than that on the bottom of the sliding block.
  7. The parting surface should not be selected at the required position of the surface.
  8. The shrinkage of the fiber with fiber is 1-2% smaller than that of the flow direction, which is larger than that perpendicular to the flow direction; otherwise, it is the opposite.
  9. The shrinkage rate of the addendum circle is 1-2 thousandth less than that of the root circle.
  10. When the die is used for a section

The exhaust pipe of turbine whistle is refitted for automobile

 exhaust pipe

This product has four models: Small Model, Medium Model , Large Model and Extra Large Model

Small Model is suitable for the displacement of 1.0-1.6, and the diameter of exhaust pipe is 32-43mm (about 67g)

Medium Model is suitable for displacement of 1.6-2.0, and the diameter of exhaust pipe is 37-48mm ( about 87g)

Large Model is suitable for the displacement of 2.0-2.4, and the diameter of exhaust pipe is 44-55mm( about 102G)

Extra Large Model is suitable for displacement above 2.4, and the diameter of exhaust pipe is 56-85 mm (about 126G)

Product Name: The exhaust pipe of turbine whistle is refitted for automobile

Easy to install, beautiful and elegant, very fashionable.Welcome to send drawings for machining

Gear processing technology

Gear processing should adopt different technology according to different structure and precision. In view of the large equipment investment, the selection of process mode (as shown in Table 1) usually takes full account of the existing resources. The control of micro deformation and process stability in the process of high-speed computer gong machining gear is relatively complex. Isothermal normalizing is usually used after blank forging in order to obtain good processing performance and uniform microstructure with trend deformation. For low-speed cylindrical gear with low accuracy requirements, gear shaving can be done before hot rolling, and no processing is required after hot rolling. There are many teeth in hot post processing of cylindrical gear according to the conditions Different from gear grinding, the cost of tooth cleaning is low, but the ability of tooth profile correction is weak, and the precision of gear grinding is high but the cost is high. The technology of edge dressing and drum tooth modification can significantly reduce the gear meshing noise and improve the transmission performance, which are widely used at present.

The straight bevel gear is mainly used in the differential. Due to the low speed and relatively low precision requirement, precision forging gear is recommended. The complicated and time-consuming manual operation of spiral bevel gear processing and machine tool adjustment has been replaced by modern special software and computer program. The introduction of finite element analysis makes the process parameter design more reliable and convenient. There are mainly two kinds of gear grinding: grinding and grinding. Due to the high cost, low efficiency and limitation of gear grinding, gear lapping is mostly used at present Recently, a large marine gear with world advanced level and equipped with adjustable propeller [gear: gear is a mechanical element with teeth on the rim that can continuously mesh and transmit motion and power. The meshing of teeth in mechanical parts has been used for a long time. Box was born in hangchi group. This product belongs to the transmission device of marine power propulsion system. It not only has the functions of deceleration, clutch and bearing propeller thrust, but also has the function of auxiliary power output and auxiliary power input, which can meet the requirements of French bv ship inspection unmanned engine room.

This product is designed and manufactured by hangchi technicians according to the order requirements of foreign customers. High speed computer gong processing synchronous belt wheel is specially equipped with adjustable paddle for transportation and ocean fishing vessels. The product is controlled by electricity and hydraulic pressure. It has clutch system and gear transmission system with clutch and deceleration functions. For the first time, the PTO / PTI function is realized on the gearbox at the same time, which can make the propeller obtain the best propulsion efficiency and realize the automatic control of ship forward and backward. The auxiliary power input can realize the function of ship emergency return when the main engine fails, and the auxiliary power output can generate power for the ship when necessary. This kind of function can be used not only as generator but also as engine, which can greatly meet the needs of users.

The product has large speed ratio and wide application range. Hangchi installed the liquid level alarm for the first time in this product. All controllers and transmitters of synchronous belt pulley are imported brands. Make its performance more safe and reliable. The gearbox adopts double pump, which simplifies the design of hydraulic system and reduces the possibility of failure.

  1. The tightness of the sprocket should be appropriate. If it is too tight, the power consumption will be increased, and the bearing is easy to wear; if the sprocket is too loose, it is easy to jump and fall off the chain. The tightness of the chain wheel is: lift or press down from the middle of the chain wheel, which is about 2% – 3% of the center distance between the two chain wheels.
  2. There should be no swing and skew when the sprocket is installed on the shaft. In the same transmission component, the end faces of two sprockets should be in the same plane. When the center distance of sprocket is less than 0.5 m, the deviation can be 1 mm; when the center distance of sprocket is more than 0.5 m, the deviation can be 2 mm. However, there should be no friction on the side of sprocket teeth. If the offset of two wheels is too large, it is easy to cause chain shedding and accelerated wear. Pay attention to check and adjust the offset when replacing the sprocket.
  3. When the sprocket is seriously worn, the new sprocket and new sprocket should be replaced at the same time to ensure good meshing. Do not replace new sprocket or new sprocket separately. Otherwise, it will cause bad meshing and accelerate the wear of new sprocket or new sprocket. When the tooth surface of the sprocket is worn to a certain extent, it should be turned over in time to extend the service time.
  4. If the new sprocket is too long or elongated after use, it is difficult to adjust. The chain link can be removed according to the situation, but it must be even. The chain link shall pass through the back of the chain wheel, the locking plate shall be inserted outside, and the opening of the locking plate shall face the opposite direction of rotation.
  5. The sprocket should be filled with lubricating oil in time. Lubricating oil must enter the clearance between roller and inner sleeve to improve working conditions and reduce wear.
  6. The old chain wheel can not be mixed with some new ones, otherwise it will cause impact in the transmission and break the chain wheel.
  7. When the machine is stored for a long time, the sprocket wheel should be removed and cleaned with kerosene or diesel oil, and then coated with oil or grease and stored in a dry place.

2、 The structural design of the sprocket:

  1. Tooth profile of sprocket

The tooth shape of the chain wheel must ensure that the chain can enter and exit the meshing smoothly and smoothly, reduce the impact and contact stress of the chain link during meshing as far as possible, and it should be easy to process.

The common tooth profile of sprocket end face is composed of three arc AA, AB, CD and a straight line BC, which is called three arc straight line profile for short. The tooth profile is processed with standard cutter. It is not necessary to draw the end face tooth profile on the sprocket working drawing. It is only necessary to mark “the tooth profile is manufactured according to the provisions of 3rgb1244-85” on the drawing. However, the axial tooth profile of the sprocket shall be drawn, as shown in Fig. 2, and the dimension shall refer to the relevant design manual. ginseng

Computer gong engraving machine

Processing center: Hong Kong, Taiwan, Guangdong area known as the computer gong, is a highly automated multi-functional CNC machine tool with tool magazine and automatic tool change device. The first machining center appeared in the United States in 1958. High speed computer gong machining can realize the centralized processing of milling, drilling, boring, reaming, tapping and other processes after the workpiece is clamped once, with special emphasis on “milling”.

Engraving machine: its spindle speed is high, suitable for small cutting tools processing, torque is relatively small, focusing on the “carving” function, such as wood (wood carving machine for special processing of wood), dual color board, acrylic plate and other plates with low hardness, which are not suitable for large workpieces with strong cutting. Most of the products on the market with the banner of engraving machine are mainly for processing handicrafts with low cost. Due to the low precision, they are not suitable for mold development. However, there are also exceptions, such as wafer engraving machine.

Carving and milling machine: as the name implies. It can be carved or milled. On the basis of the engraving machine, the power of the spindle and servo motor is increased, and the bearing force of the lathe bed is maintained. At the same time, the high speed of the spindle is maintained. More importantly, the precision is very high. Engraving and milling machine also to high-speed development, commonly known as high-speed machine, cutting ability is stronger, processing accuracy is very high, but also can directly process hardness above HRC60 materials, one-time molding.

The highest spindle speed (R / min): Machining Center 8000; engraving and milling machine is the most common 240000, high-speed machine is the lowest 30000; engraving machine is generally the same as engraving and milling machine, the engraving machine used for high gloss processing can reach 80000, but the air bearing spindle is not used.

Spindle power: the machining center is the largest, ranging from several thousand watts to tens of kilowatts; carving and milling machines are the second, generally within ten kilowatts; engraving machines are the smallest.

Cutting capacity: high speed computer gong machining center is the largest, especially suitable for heavy cutting and rough cutting; engraving and milling machine is the second, suitable for finishing; engraving machine is the smallest.

Speed: because engraving and milling machines and engraving machines are light and light, their moving speed and feed speed are faster than the machining center, especially for high-speed machines equipped with linear motor, the maximum moving speed is 120m / min

Accuracy: the accuracy of the three is similar.

From the processing size: the worktable area can better reflect this. The smallest worktable area (unit mm, the same below) of domestic machining center (computer gong) is 830 * 500 (850 machines); the largest worktable area of engraving and milling machines is 700 * 620 (750 machines), and the smallest is 450 * 450 (400 machines); engraving machines generally do not exceed 450 * 450, and the common ones are 45 * 270 (250 machines).

In terms of application objects: the machining center is used to complete the processing equipment of large milling amount of workpieces, large molds and materials with hardness comparison, which are also suitable for the opening of common molds; the engraving and milling machine is used to finish the finishing of small molds with small milling amount, which is suitable for copper and graphite processing; the low-end engraving machines are inclined to those with low hardness such as wood, double color board and acrylic plate Plate processing, high-end suitable for wafer, metal shell polishing and polishing.

Generally speaking, machining center and engraving and milling machine can do both products and molds, while engraving machine can only do products.

Tool magazine: Machining Center, where there is a tool library, is a machining center; if there is no tool library, it is called computer gong or CNC milling; generally, engraving and milling machines do not have a tool library, even if the tool magazine is selected, it is umbrella type tool library with 12 knives or in-line tool library with 6 knives; carving has no tool library.

In foreign countries, there is no term for CNC Engineering and milling machine. Strictly speaking, carving is a part of milling, so there is only the concept of machining center in foreign countries, and the concept of small machining center is derived to replace engraving and milling machine. Purchase engraving machine or CNC milling machining center is often asked their own questions, to see the actual production needs. In addition, there is a popular high-speed cutting machine (hscmachine), which is called high-speed machine in China.

2、 Analysis from the angle of numerical control

  1. — the CNC milling center requires a general speed for the CNC system, and the spindle speed is about 0 ~ 8000 rpm
  2. – engraving and milling machine requires high-speed CNC system, high-speed computer gong processing spindle speed of 3000 ~ 30000 rpm
  3. High speed cutting machine requires high-speed CNC system and excellent servo motor characteristics, spindle speed of 1500 ~ 30000 rpm

The highest spindle speed (R / min): Machining Center 8000; engraving and milling machine is the most common 24000, high-speed machine is the lowest 30000; engraving machine is generally the same as engraving and milling machine, engraving machine used for high gloss processing can reach 80000, but it uses air bearing spindle instead of ordinary motorized spindle.

Spindle power: the machining center is the largest, ranging from several thousand watts to tens of kilowatts; carving and milling machines are the second, generally within ten kilowatts; engraving machines are the smallest.

Cutting amount: machining center is the largest, especially suitable for heavy cutting and rough cutting; engraving and milling machine is the second, suitable for finishing; engraving machine is the smallest.

Speed: because engraving and milling machines and engraving machines are light and light, their moving speed and feed speed are faster than the machining center, especially for high-speed machines equipped with linear motor, the maximum moving speed is 120m / min

Accuracy: the accuracy of the three is similar.

From the processing size: the worktable area can better reflect this. The smallest worktable area (unit mm, the same below) of domestic machining center (computer gong) is 830 * 500 (850 machines); the largest worktable area of engraving and milling machines is 700 * 620 (750 machines), and the smallest is 450 * 450 (400 machines); engraving machines generally do not exceed 450 * 450, and the common ones are 45 * 270 (250 machines).

From the application object: the machining center is used to complete the processing equipment of large milling amount of workpieces

Computer gong deep hole processing

Do CNC deep hole processing friends should know that CNC processing, deep hole processing is the most difficult. The so-called deep hole machining is the processing that the ratio of the length of the hole to the diameter of the hole is greater than 10 times. The deep hole processing is applied in some industrial fields of the country, such as the national military rocket body and the barrel of various guns. In these application fields, some require very high quality and precision of machining, and some require high cutting ability of processing materials The so-called CNC is the abbreviation of computer numerical control machine tool, which is the technology required for programmed control, automation and high-tech.

CNC technology is applied to deep hole processing. Because the processing technology and method of computer gong machining are very complex, few people use CNC machining center to process deep hole. If this technology is used, first of all, we should transform the CNC machining center to vibration deep hole drilling machine, and combine the advanced deep hole machining vibration cutting technology with AC frequency conversion speed regulation technology Together, it forms a kind of precise professional processing technology. This kind of precise CNC deep hole processing technology effectively applies the vibration cutting technology to the drilling process. On the basis of the traditional deep processing technology, the amplitude and frequency of the regular vibration of the tool used are given. In the process of cutting tool running, the cutting work is completed by vibration at the same time, and the cutting thickness changes periodically, so as to achieve the purpose of NC cutting according to the predetermined shape and size. Thus, the problem of chip removal interruption in CNC deep hole machining is effectively solved, and the quality and efficiency of deep hole machining are improved.

After years of efforts, the development of domestic ultra precision machining equipment has begun to take shape. The indicators of many equipment for machining mechanical parts, including aspheric surface composite machining system, have reached or approached the world advanced level In terms of reliability and operability, there is still a certain gap. How to better play the role of equipment requires further human and material investment. For example, the nano sys-300 aspheric surface compound processing equipment of our laboratory has been in the production line service since it was delivered to the user in May 2003. It has processed many batches of task parts, which can fully meet the requirements of users in terms of processing accuracy, but there is still much room for improvement in other aspects, such as operability and reliability. Therefore, it is necessary to strengthen the research on the reliability and practicability of ultra precision machining technology.

With the development of science and technology, more and more advanced new functional materials and structural materials will be applied, including new high strength, high hardness materials, intelligent materials, new semiconductor materials, and so on. For example, the processing technology of SiC reinforced composite materials used in satellite cameras, the ultra precision turning technology of infrared materials such as germanium, monocrystalline silicon and calcium fluoride glass, and the flying cutting process of KDP crystal (laser fusion), etc.

MEMS processing technology mainly includes silicon planar process and bulk silicon process developed from semiconductor processing technology. Since the mid-1980s, LIGA technology, which uses X-ray lithography, electroforming and injection molding, was born, forming another MEMS processing system. The processing technology of MEMS can include silicon micromachining for surface and bulk machining, Liga machining and quasi Liga machining using UV lithography, micro EDM, ultrasonic machining, plasma machining, laser machining, ion beam machining, electron beam machining, stereolithography, etc.

However, the components of these micromachines are various and complicated. In order to make the performance of micromachines really pass the standard and reach the practical level, it is necessary to improve the manufacturing technology and equipment level of micro mechanical parts as soon as possible. At present, lithography is the most mature technology in the manufacturing process of micro mechanical parts. Most of the classic micro mechanical parts are made by lithography or electroforming technology. However, the micromechanical parts processed by these mature technologies can only be two-dimensional (or quasi three-dimensional), and the actual three-dimensional shape parts can not be completed by lithography technology. There are many three-dimensional micro parts in CNC machining center, such as micro mold, micro thread with diameter of 70 μ m, micro rack, pin with diameter of 50 μ m, stepped shaft with diameter of 200 μ m, 100 μ m and 50 μ m, and rotary polishing with outer diameter of 300 μ M The processing of these typical three-dimensional micro parts can not be realized not only by lithography, three beam processing, but also by traditional mechanical manufacturing system. Therefore, it is necessary to develop and develop a micro manufacturing system according to the characteristics of three-dimensional micro machines. In this new concept manufacturing system, the processing, detection and assembly of micro machine parts can be realized. The manufacturing system of micro machine, which is composed of micro equipment, is called micro manufacturing system. The technical problems include the processing, detection and assembly of micro machine parts. The research work in this field is mainly concentrated in Japan and the United States. In this regard, Japan first put forward the concept of micro desktop factory.

However, it is not necessary to use micromachining machine tools to process micro mechanical parts, such as the characteristics of machine tools for processing instrument parts