Category Archive Machinery industry

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How to prevent the spindle from colliding with the workpiece

The feed speed of CNC machining center has increased from 16m / min in 1980s to 24-40m / min now. The spindle speed of CNC machining center has also increased from 2500r / min to 6000-40000 R / min now. The structure of CNC machining center has also changed from open type to closed type. Under the condition of such high speed and structure, once the operator has no time to press the emergency stop button due to programming and operation errors, the tool has collided with the workpiece.

In order to prevent machine tool and personal troubles, the following methods can be adopted in programming and operation (take FANUC system as an example).

Under normal conditions, the origin of workpiece coordinate system can be set anywhere, as long as the origin has a certain connection with the origin of machine coordinate system. But in practice, if the command value is zero or close to zero, the tool will point to zero or close to zero. In milling, the cutter will run to the table or fixture base surface; in turning, it will run to the chuck base surface. In this way, the tool will penetrate the workpiece and point directly at the reference plane. At this moment, if you want to move quickly, you will have trouble.

FANUC system generally set: when the decimal point is omitted, it is the minimum input unit, generally μ M. When the decimal point is omitted, the input value will be reduced to one thousandth. At this moment, the input value will be close to zero. Perhaps, due to other factors, the tool should be separated from the workpiece, but the practice is not separated from the workpiece and into the workpiece. In this case, the zero point of the workpiece coordinate system should be set outside the workpiece or on the base surface of the worktable (or fixture), and the result will be different.

Programmers and operators should be more careful about decimal points when writing programs.

FANUC system is the minimum setting unit when the decimal point is omitted, while most domestic systems and some European and American systems are mm when the decimal point is omitted, which is the input method of calculator. If you are used to calculator input method, there will be problems in FANUC system. Many programmers and operators may use both systems. In order to prevent the scale from getting smaller due to decimal point, decimal point should be added to the input program of calculator. To do so is surplus for a certain kind of system, but after the habit is formed, there will be no problems due to the decimal point.

In order to make the decimal point eye-catching, the isolated decimal point is usually written as “. 0” in programming. Of course, when the system is executed, the zero after the decimal point of the value is ignored.

When adjusting the workpiece coordinate system, the operator should set the reference point beyond the physical (geometric) length of all tools, at least on the tool position of the longest tool.

For the workpiece coordinate system on the workpiece installation drawing, the operator obtains it by setting the machine coordinate system offset on the CNC machining center. In other words, the operator sets a reference point on the CNC machining center, finds the scale between the reference point and the zero point of the workpiece coordinate system set by the programmer, and sets this scale as the workpiece coordinate system offset.

On the lathe, the datum point can be set on the base of turret rotation, the datum tool tip or other directions. If there is no additional movement, the zero of the programmer’s instruction is the zero position of the tool rest (CNC machining center) moving to the offset. At this moment, if the datum point is set at the base of turret rotation, the turret must collide with the workpiece. In order to avoid collision, the datum point of CNC machining center should not only be set outside the tool holder, but also outside all tools. In this way, even if the tool is installed on the tool holder, the datum point will not collide with the workpiece.

In CNC machining center, the datum points of X and Y axes are on the axis line of spindle. However, the reference point of the z-axis can be set at the spindle end or at a point other than the spindle end. If it is at the spindle end, when the command is zero, the spindle end will reach the zero position specified in the coordinate system. At this moment, the end key of the spindle end will collide with the workpiece: if the spindle is equipped with a tool again, it will collide with the workpiece. To ensure that there is no collision, the reference point on the z-axis should be set beyond all tool lengths. Even if no other motion is attached, the reference point will not hit the workpiece.

Bychengcg

Computer gong processing to prevent accuracy error

It is impossible to make the machining exactly the same as the ideal part, and there will always be different deviations. The deviation degree of the actual geometric parameters after machining from the ideal geometric parameters is called machining error. These machining errors often appear in “large machining process”,

The details are as follows:

Processing economic precision

Because there are many factors affecting the machining accuracy in the machining process, the same machining method can achieve different accuracy under different working conditions. The processing error delta is inversely proportional to the processing cost C. The processing economic precision of a certain processing method should not be understood as a certain value, but as a range, which can be said to be economic.

Original error

There are all kinds of errors in the machining process system composed of machine tool, fixture, cutter and workpiece. These errors will be reflected as the machining errors of workpiece in different ways (or expanding or shrinking) under different working conditions.

The original errors of process system mainly include geometric error, positioning error, processing error caused by force deformation, processing error caused by heat deformation, deformation caused by redistribution of internal stress, principle error, adjustment error, measurement error, etc.

2、 Set error of process system

  1. Geometric error of machine tool

In machining, the forming movement of the tool relative to the workpiece is generally completed by the machine tool. Therefore, the machining accuracy of the workpiece depends on the accuracy of the machine tool to a great extent. The manufacturing errors of machine tools have great influence on the machining accuracy of workpieces: spindle rotation error, guide rail error and transmission chain error. The wear and tear of the machine tool will reduce the working accuracy of the machine tool.

Spindle rotation error

The spindle of machine tool is the datum for clamping the workpiece or cutter, and transmits the motion and power to the workpiece or cutter. The rotation error of spindle will directly affect the accuracy of the workpiece to be processed.

The spindle rotation error refers to the variation of the actual rotation axis of the spindle at each instant relative to its average rotation axis. It can be divided into three basic forms: radial circular runout, axial movement and angular swing.

The main reasons for the radial rotation error of the spindle are: the coaxiality error of several sections of the Journal of the spindle, various errors of the bearing itself, coaxiality error between the bearings, spindle winding, etc. But their influence on the radial rotation accuracy of the spindle varies with different machining methods.

The main reason for the axial movement is the verticality error between the end face of the spindle shoulder and the bearing end face of the spindle rotation axis.

In the process of large-scale machining, the machining error caused by spindle rotation error is different with different machining methods. When machining outer circle and inner hole on lathe, the radial rotation error of spindle can cause roundness and cylindricity error of workpiece, but it has no direct effect on the end face of workpiece. The axial rotation error of CNC machining spindle has little influence on machining outer circle and inner hole, but has great influence on the perpendicularity and flatness of machined end face. When turning the thread, the spindle rotation error can make the lead of the processed thread produce periodic error.

Bychengcg

High speed computer gong processing power

Large gantry milling machining center has a strong ability, the workpiece can finish more processing content after clamping at one time, and the processing accuracy is high. For the batch workpiece with medium processing difficulty, its power is 5-10 times of that of general equipment, especially it can finish the processing that many general equipment can’t finish, and it is more suitable for the single piece processing with messy shape and high precision or small and medium batch production with many kinds Use. Here is a brief introduction to the idea of gantry milling machine.

  1. The safe operation of large gantry milling machining center has the following points:

The working object should be clamped by pressing plate, screw or special tool. The general wrench is not allowed to add casing, so as to avoid slipping and injury.

The cutting tool must be clamped firmly, otherwise it is not allowed to drive.

Before work, check the operation of the transmission part of the machine tool, and install the baffle of the machine tool before operation.

When milling various workpieces, especially rough milling, slow cutting should be carried out at the beginning.

When moving the worktable and tool rest, loosen the fixing screw first.

When loading and unloading tools, use copper hammer or wooden mallet to gently hit to prevent tool fragments from flying out and injuring people.

In cutting, it is not allowed to change the speed and adjust the cutting tool. It is not allowed to touch or measure the workpiece by hand.

  1. The gantry milling machine bed is equipped with X-axis guide rail, and the gantry milling machine worktable is fixed on the bed. A gantry is erected on the movable span above the worktable, and the gantry also includes a gantry carriage, which is clamped on the x-axis guide rail. The z-axis guide rail is installed on the gantry. The crossbeam is provided with a Z-axis carriage, the crossbeam is movably clamped on the z-axis guide rail through the z-axis carriage, and the crossbeam is also provided with a Y-axis guide rail.

The milling device of the gantry milling machine is movably installed on the y-axis guide rail, so that the gantry can be milled in the three-dimensional space of X, y and Z axes under the control of the numerical control circuit control system. The CNC gantry milling machine has high precision milling, drilling, boring, cutting and other operations.

a. Reasonable selection of equipment. High machining accuracy is required. Roughing is mainly to cut off most of the machining allowance. Rough machining should be carried out on the machine tool with high power and low precision, while finish machining should be carried out on the machine tool with high precision. Rough machining and finish machining are processed on different machine tools, which can not only give full play to the equipment capacity, but also extend the service life of precision machine tools.

b. In order to ensure the machining accuracy, rough and finish machining should be carried out separately. The amount of cutting is large, because when rough machining. For some parts with high machining accuracy. After roughing and before finishing, low temperature annealing or aging treatment should be arranged to eliminate the internal stress. The cutting force and clamping force of the workpiece are large, the calorific value is large, and there is a significant work hardening phenomenon on the surface of the workpiece. There is a large internal stress in the workpiece. If the rough and rough machining is carried out continuously, the precision of the finished part will be lost quickly because of the redistribution of the stress.

c. Heat treatment process is often arranged in machining process. In order to improve the mechanical properties of parts, quenching and tempering are generally arranged after machining. The location of heat treatment process is as follows: in order to improve the cutting performance of metal, such as annealing, normalizing, quenching and tempering, it is generally arranged before machining. In order to eliminate internal stress, such as aging treatment, quenching and tempering treatment, it is generally arranged after roughing and before finishing. There are many tool materials that can be used in large spark machining, such as diamond, graphite, Cu. Cu based alloy and Cu based composite, and polymer composite is also one of the tool materials for spark machining.

At present, the components of polymer composites used in spark machining are still in the stage of research and development. Good plastic electrodes should have high thermal conductivity, good formability, low resistivity, dimensional stability in water, low coefficient of thermal expansion, and thermal cycling. Compared with graphite electrode, a tool material for spark machining, it has the advantages of low cost, and can be molded into complex geometry. Its manufacturing speed is much faster than milling. The other advantage is that the density is relatively low and the resistivity is relatively high. Therefore, the loss rate of the electrode will be relatively high, but the electrode is in the process of milling In the process of use, it can be trimmed by re molding.

At present, a conductive thermoplastic polymer composite material is used as the electrode, and air and water are used as the working medium to process or polish the surface of the workpiece. Then 60% – 65% of the solid carbon material is evenly distributed in the thermoplastic matrix material to make the electrode. The required geometry can be softened and molded repeatedly.

Bychengcg

Influence of tool material on machining quality

Numerical control technology is also called CNC (computerized numerical control). At present, it is the technology of using computer to realize digital program control. In this technology, the computer can control the movement track of the equipment and the operation sequence logic of the peripheral equipment according to the control program stored in advance. Because the numerical control device composed of hardware logic circuit is replaced by computer, all kinds of control functions such as storage, processing, operation and logic judgment of input operation instructions can be realized by computer software, and the micro instructions generated by processing are transmitted to the servo driving device to drive the motor or hydraulic actuator to drive the equipment.

The traditional machining is operated by hand, the ordinary machine tool is used to cut metal by hand, and the accuracy of products is measured by eyes with calipers and other tools. Modern industry has already used computer digital control machine tools for operation, CNC machine tools can automatically process any product and parts directly according to the pre programmed program of technicians. This is what we call NC machining. NC machining is widely used in all fields of machining, and it is the development trend and important and necessary technical means of mold processing. Over the years, users in accordance with the standard, interchange the use of a variety of tool manufacturers produced by the milling cutter and blade. However, these standards make various restrictions on milling cutters and inserts, including the shape and thickness of the inserts, the inscribed circle of the cutting inserts, the size of the holder and wedge clamping parts, and the size of the cutter body. Due to the limited design range of blade material, edge and chip breaking groove, the tool suppliers and users who abide by the standard are limited by the machining function.

However, today, the concept of milling cutter tends to be flexible, which provides tool developers with the freedom to adopt new tools and blade design. These designs can be optimized, and the use of new tool concept can better solve the problems of machining safety, accuracy, appearance quality, metal removal rate, tool overhang, high-speed cutting, and the ability of different cutting paths.

Today’s milling tools are constantly optimized to meet the needs of modern production, machine tools and data, and are widely accepted by all industries. The new tool can remove metal several times faster, with smaller cutting force and better orientation. Its typical runout is only a fraction of the old standard tool. Therefore, the machining tolerance can always be controlled in a smaller range, and the loss of cutting edge is also smaller and more ideal. The axial and radial runout are very small, which means that the accuracy of the cutting edge is improved, so the appearance quality of the workpiece is better, the tolerance is smaller, the tool life is longer, and the cutting load is more uniform, so as to improve the cutting speed and reduce the noise, vibration and loss.

The use of tools also helps to increase spindle speed, high-speed feed and hard part milling, and expands the opportunities for dry cutting. The design of these cutting tools is more concise, and the workload and time required for adjustment and maintenance are very small. The cutter body is rigid and accurate in size. It is made of pre hardened steel, which ensures that the blade is accurately and firmly installed on the milling cutter body, and the appropriate pitch can be selected according to different applications.

The new milling tools use the blade material and groove type developed for specific data or process. The functions and achievements of the new milling tools with these blades are far better than those of ISO or ans standard tools and blades. Compared with most standard inserts, modern new inserts and tools can provide larger rake angle and more complex groove, thus reducing the cutting force and forming the synergistic effect of faster and more stable metal removal.

Bychengcg

Program manual code – computer gong processing

  1. G00 and G01 G00 have two kinds of motion paths: straight line and broken line. In computer gong processing, the command is only used for point positioning, not for cutting. G01 moves to the target point specified by the command in a straight line according to the specified feed speed, which is generally used for cutting
  2. G02 and G03 G02: clockwise arc interpolation G03: counterclockwise arc interpolation
  3. G04 (delay or pause command) is generally used for forward and reverse switching, processing blind hole, step hole, turning and grooving
  4. G17, G18, G19 plane selection instruction, mechanical parts processing designated plane processing, generally used for milling machine and machining center G17: X-Y plane, can be omitted, can also be parallel to the X-Y plane, G18: x-z plane or parallel plane, CNC lathe only x-z plane, do not use special designated G19: Y-Z plane or parallel plane
  5. G27, G28, g29 reference point command G27: return to the reference point, check and confirm the position of the reference point G28: automatically return to the reference point (through the middle point) g29: return from the reference point, use with G28
  6. G40, G41, G42 radius compensation G40: cancel tool radius compensation
  7. G43, g44, G49 length compensation G43: length positive compensation g44: length negative compensation G49: cancel tool length compensation
  8. G32, G92, G76 G32: thread cutting G92: thread cutting fixed cycle G76: thread cutting compound cycle
  9. Turning: G70, G71, 72, G73 G71: axial rough turning compound cycle instruction G70: finishing compound cycle G72: end face turning, radial rough turning cycle G73: profiling rough turning cycle
  10. Milling machine, machining center: G73: high speed deep hole pecking drill g83: deep hole pecking drill g81: drilling cycle g82: CNC machine tool processing deep hole drilling cycle G74: left screw thread processing g84: right screw thread processing G76: fine boring cycle g86: boring cycle g85: reaming g80: cancel cycle command
  11. Programming mode G90, G91 G90: absolute coordinate programming G91: incremental coordinate programming
  12. Spindle setting command G50: spindle maximum speed setting G96: constant linear speed control g97: spindle speed control (cancel constant linear speed control command) G99: return to R point (middle hole) g98: return to reference point (last hole)
  13. Spindle forward and reverse stop command M03, M04, M05 M03: spindle forward M04: spindle reverse M05: spindle stop
  14. Cutting fluid switch M07, M08, M09 M07: mist cutting fluid on M08: liquid cutting fluid on M09: cutting fluid off
  15. Examples of M00, M01, M02 and M30 programs are given. For example, use a 30 diameter milling cutter to process a circle with a diameter of 40. Set the relative coordinates of the circle center as x0y0 g0g90x0y0z100. Quickly locate the position Z2 of the circle center height 100 to the position g1z-1 of height 2. F100 moves from the set f speed 100 (i.e. tool speed) to the position of height-1 (if the workpiece surface is set as zero point, Then it is cutting into the surface of the workpiece (1mm) g91g01x-5.f200 (starting point of cutting into the circle) g02i5. (take the origin as the center of the circle and circle clockwise) X5. (leave the workpiece to the center of the circle) g0g90z100. (Z axis quickly rises to the position of Z100) M30 (end of the program)
Bychengcg

Quotation of computer gong processing

The operation process of the machining cost center of mechanical parts is as follows:

  1. Inquiry process:

Receive business, purchase new products, material notice, information – > inquiry to understand the content, CNC machine tool processing to confirm the demand, seek suppliers to check the quotation before similar products, manufacturer’s quotation, unit price confirmation, submit to the supervisor for approval, respond to relevant units to track and confirm the unit price and other information, feedback and report.

  1. Valuation process:

Following the content analysis of the evaluation form of business development (whether it is necessary to ask for inquiry outside the contract), fill in the original of the evaluation form approved by the supervisor and send it to the business department to track the confirmation of the quotation. The business will submit the confirmed original quotation details to the cost center and input them into the computer for final confirmation of each process cost (including processing, outsourcing, purchasing materials, etc.)

  1. The proportion of cost analysis;

The proportion of materials in the whole product sheet is 30% – 50% for the panel and 50% – 80% for the heat sink

After work, the cost center should go to the production line to understand the actual manufacturing process, regularly capture the change trend of the aluminum ingot Market and the exchange rate of each currency on the Internet, care about the aluminum industry market, and quote the most reasonable unit price.

Quotation method and standard

  1. Calculation method of material weight:

Weight formula:

Product gross weight = sectional area X specific gravity x [product length + saw blade (4-5mm)]

The specific gravity of aluminum extrusion is calculated as 2.8x103kg/m, while that of aluminum plate is calculated as 2.75x103kg/m.

② If the length of the above product is 220mm, the weight of the product is:

(220+5)x3.159=710.8 g

  1. Calculation formula of sectional area:

① . equilateral triangle:

Area s = a * H / 2 = 0.433a2 or 0.578h2

② Right triangle:

Area s = a * B / 2 h = a * B / C

③ . flat quadrilateral and rectangle:

Area s = b * h

④ . diamond shape:

Area s = D * H / 2 a = 1 / 2 D

⑤ . Square:

Area s = a * a d = 1.414 a

⑥ . trapezoid:

Area s = (a + b) * H / 2 or m * h, M = (a + b) / 2

⑦ . round:

Area s = π / 4 * D2 or S = π / 4 * D2

⑧ . ellipse:

Area s = major axis radius * minor axis radius * π = a * b * π

⑨ . ring:

Area s = π / 4 (d2-d2) or S = π / 4 (r2-r2)

⑩ . fan shaped:

Area s = π R2 * а / 360 or S = R / 2 * l

(11) bow shape:

Area s = L * r / 2-C (R-H) / 2

(12) parabolic arch

Area s = 2 / 3B * h

  1. When calculating the cross-sectional area of the product, the subsequent processing loss of the product, such as grinding allowance, should be considered.
  2. Calculation method of the number of plates to be cut:

The specifications of the plate materials used are as follows: 1.22m * 2.44m, 1m * 2m, 1m * 2.2M, etc.

The calculation method is as follows:

For example: for t2.0 aluminum plate, when the blanking size is 100 mm * 50 mm and 1.22 m * 2.44 m plate is used, the blanking size is:

(2440 / 100) * (1220 / 50) = 576pcs

That is to say, one aluminum plate of this specification can produce 576pcs products.

Since the weight of a 2.0 * 1.22 * 2.44m aluminum plate is 16.5kg, the weight of each product is calculated as follows:

16.5 * 1000 / 576 = 28.65g, that is, the weight of each product is 28.7g

  1. The proportion of common materials is as follows:

Aluminum: 2.78g/mm2 iron: 7.8g/mm2 copper: 8.94g/mm2

  1. The quotation basis for each process is as follows (HK $):

1) As for the unit price per kilogram of materials, it depends on the international market and the types of products

Generally speaking, the unit price of H / s material is 28-30 HKD / kg, while that of F / P material is 30-32 HKD / kg

Copper material is quoted at 65-70 HKD / kg

Copper coil is quoted at 70-75 HKD / kg, aluminum coil is quoted at 32-35 HKD / kg

The price of SPCC is 7-9 HKD / kg, while that of SECC is 8-12 HKD / kg

2) . cutting:

According to the extrusion area, product shape and cutting length, the width and thickness of the extrusion are as follows:

Panel: 150 MM-200 mm 0.6-1 / PCS

100mm—150mm 0.3–0.7/pcs

50mm—100mm 0.15–0.4/pcs

Below 50 mm 0.1 — 0.2/pcs

Large heat sink (AMP)

0.8-1.0/pcs above 200 mm

150mm—200mm 0.6—1.0/pcs

100mm—150mm 0.3—0.7/pcs

50mm—100mm 0.15—0.4/pcs

Small radiator (sPS / UPS)

0-1.0/pcs above 200 mm

150mm—200mm 0.6—0.8/pcs

50mm—100mm 0.15—0.4/pcs

0.1-0.2/pcs below 50 mm

CPU radiator: 0.03-0.15/pcs

3) . plastic surgery:

According to the actual situation, thickness and customer requirements, it is generally as follows:

Appearance panel class:

0-1.0/pcs above 200 mm

150mm—200mm 0.3—0.5/pcs

0.15-0.3/pcs below 150 mm

Large radiators:

0-1.0/pcs above 200 mm

150mm—200mm 0.5—0.8/pcs

80mm—150mm 0.3—0.5/pcs

0.1-0.4/pcs below 80mm

4) . stamping:

Calculated by the number of stamping times, the unit price varies according to the tonnage of the punch used and the rise and fall of the product. As follows:

Radiator:

Below 8t-15t: 0.03-0.1/time 15t-25t: 0.05-0.12/time

35t: 0.08-0.18/time 45t-50t: 0.1-0.2/time

60t: 0.15-0.3/time 110t: 0.3-0.5/time

160t: 0.5-1.0 per time

Panel class:

15t: 0.35-0.45/time 25t: 0.4-0.5/time

35t-50t: 0.5-0.6/time 60t: 0.6-0.7/time

110t: 0.7-1.0/time 160t: 0.9-1.2/time

5) Drilling / tapping: in principle, it depends on the number of holes, but it is different for multi axis tapping.

In general, H / S is 2-3mm in diameter, 0.05-0.075 per time in depth below 8mm, and 0.1-0.15 per time in case of more than 5 holes

Depth 8mm to 15mm: 0.1-0.15, many holes (more than 5 holes)

15-0.2 per time

The diameter is more than 4 mm; the depth is less than 8 mm: 0.075-0.1; the number of holes is more than 5

15 – 0. 25 per time

More than 8 mm depth: 0.12-0.2, more holes (more than 5 holes),

15-0.25 per time

It can be used for large H / s, 2-3 mm in diameter, 0.075-0.1 per time in depth below 8 mm, and 0.1-0.15 per time in case of more than 5 holes

The depth is 8mm-15mm: 0.12-0.2, with more holes (more than 5 holes)

15-0.25 per time

If the diameter is more than 4 mm, the depth is less than 8 mm, 0.12-0.15, and there are more holes (more than 5 holes), then 0.25-0.35 can be used once

More than 8 mm in depth: 0.15-0.3, more holes (more than 5 holes)

3-0.4 per time

The multi hole drill can be used for one time, and the tapping unit price depends on the situation, which is almost the same as drilling.

6)。 Chamfering: the unit price depends on the chamfering size, depth, product weight and the number of holes.

The panel diameter is less than 6 mm: 0.05-0.08/hole

Large radiator: about c0.5: 0.025–0.05/hole

Above c1.0: 0.075 — 0.1/hole

Small radiator: about c0.5: 0.013-0.03/hole

Above c1.0: 0.035-0.05

7) . milling hole: depending on the size and depth of the hole

General milling teeth: (over 15mm): φ 6: 0.15-0.25/hole.

8) . milling plane:

Each flat inch is calculated as: 0.25-0.4, depending on the size of the area.

9) . CNC processing:

Generally, it is calculated at 1.7 yuan / min, and it is related to the number of tool setting times. Rough and finish milling depends on the appearance requirements of the product

The unit price is different.

A: Rough milling is estimated according to the cutting speed of 250mm-300mm per minute, and if finishing milling is needed, it is x2 times.

B: Both ends of the mill, regardless of size, are calculated according to 2.0 yuan.

C: The front side needs to be refined with a fine knife, and the non front side needs to be processed with a sharp knife.

10) . deburring:

It is related to the shape of cross section, ranging from 0.05 to 1.0 per time

11) . grinding:

According to different customers of different product shape, different surface requirements

Generally 0.08-0.2 HKD per square inch, depending on the thickness of the line

12) . sandblasting:

According to the requirements of different customers, sand size and brightness

Generally, it is calculated as 0.08-0.15 HKD per square inch, otherwise. 80 × 1.1 if there are blade teeth,

More than 100 × 1.2

13) . baking paint:

0.06-0.08 HKD per square inch for white and black paint and 0.06-0.08 HKD per square inch for yellow paint

0.07-0.1 HKD, 0.15 HKD per square inch for special colors.

For the following products, the cost of baking paint is as follows:

1.115/652tb1502 baking yellow paint

colour

number

Amount of paint

Unit price / kg

Cost / PCS

Amount of solvent

Unit price / kg

Cost / PCS

yellow

Z01-H159A

0.15KG/PCS

27HKD/KG

4.05HKD

0.3KG/PCS

9HKD/KG

2.7HKD

In1542 for each paint

(4.05+2.7)/154=0.044 HKD

If the loss is 10%, the cost is: 0.044 * 1.1 = 0.048 HKD

Therefore, the cost center of baking yellow paint is 0.048 * 1.2 = 0.06 HKD / in2

2.040/1403-6380-0 baking black

colour

number

Amount of paint

Unit price / kg

Cost / PCS

Amount of solvent

Unit price / kg

Cost / PCS

black

CE7017F12

0.1KG/PCS

27HKD/KG

2.7HKD

0.15KG/PCS

9HKD/KG

1.35HKD

And the baking area is 101in2, that is, the paint used for each in2 is 101in2

(2.7+1.35)/101=0.04 HKD

If the loss is 10%, the cost is: 0.04 * 1.1 = 0.044 HKD

Therefore, the cost center of baking yellow paint is 0.04 * 1.2 = 0.055 HKD / in2

14) . degreasing:

For smaller H / s with larger area, it should be calculated according to the area. For the blind hole degreasing, according to the customer’s high quality requirements and calculation.

15) . oxidation:

The unit price is related to the oxidized color, weight and oxidized area.

Panel type: generally, whether to calculate by area depends on different extrusion shape.

Radiator: it is generally calculated by weight, but it is also calculated by area for H / s with larger area.

Bychengcg

High speed computer gong processing operation

Quality standard of die surface parts processed by high speed computer gong

1、 The purpose and action of high speed Gong processing temperature control on formability. The appearance of products, physical properties of materials and forming cycle are significantly affected by die core temperature. In general, it is ideal to keep the core temperature low to increase the injection times. However, the forming cycle related to the shape of the product (core structure) and the type of finished material also depends on the need to increase the core filling temperature.

2、 In order to prevent the temperature control of stress, this is the problem of forming material, the only requirement is cooling rate. The cooling time is short. Even if some parts are hardened and some parts are soft, the stress caused by uneven shrinkage can be avoided. That is to say, proper temperature control can improve the properties of cooling stress.

3、 Temperature control of crystallizing degree adjustment of forming material. It is necessary to improve the crystallization properties of polyurethane, polyester, etc.

  1. Computer gong processing fastening parts, check whether the fastening parts loose, damage phenomenon, the way is to find the same specification of metal stamping parts for replacement.
  2. The edge of metal stamping must be ground after a long time of use. After grinding, the edge surface must be demagnetized without magnetism, otherwise the metal stamping is prone to material blocking.
  3. In the process of use, the punch is easy to break, bend and gnaw. The punch sleeve is generally gnawed. The damage of the punch and the punch sleeve for metal stamping is generally replaced with parts of the same specification. The punch parameters mainly include the size of the working part, the size of the installation part, and the length size.
  4. High speed Gong processing hardware stamping parts, such as pressure plate, uniglue, etc., discharge parts, such as stripper, pneumatic top material, etc., during maintenance, check the parts of the relationship and whether there is damage, repair the damaged parts, pneumatic top material check whether there is air leakage, and take measures for the specific situation, such as the replacement of air pipe damage.

Basic program of large computer gong processing

  1. Large scale computer gong processing accuracy requirements, a mold is generally composed of female mold, male mold and mold base, some may also be multi-component module. As a result, the combination of the upper and lower modules has high precision. The dimensional accuracy of precision die for machining mechanical parts is often up to μ m level.
  2. The shape and surface of some products, such as automobile panels, aircraft parts, toys and household appliances, are complex. The surface of the shape is composed of a variety of curved surfaces. Therefore, the cavity surface of the mold is very complex. Some surfaces must be treated mathematically.
  3. The production of small batch mold is not mass production, in many cases, only one batch is produced.
  4. There are many working procedures for large-scale computer gong, and many working procedures such as milling, boring, drilling, reaming and tapping are always used in mold processing.
  5. The service life of repetitive production mould is long. When the service life of a pair of molds exceeds its service life, it is necessary to replace the new molds, so the production of molds is often repetitive.
  6. In the mold production of copying process, sometimes there is neither drawing nor data, and the copying process should be carried out according to the real object. This requires high imitation accuracy and no deformation.
  7. Large computer gong processing mold material is excellent, high hardness, the main material of the mold is made of high-quality alloy steel, especially high life mold steel. This kind of steel has strict requirements from blank forging, processing to heat treatment. Therefore, the establishment of processing technology can not be ignored, and heat treatment deformation is also a serious problem in processing. The basic operation of high-speed Gong machining requires that the working performance of high-speed Gong machining center is an important prerequisite for mold manufacturing industry to process mold efficiently and accurately. Driven by drive technology, many different types of high-speed machining centers with innovative structure and excellent performance have emerged. Do not place obstacles around the high-speed machining center to ensure that the working space is large enough; do not splash water or oil on the ground to ensure that the working ground is clean and dry; do not move or damage the warning signs installed on the machine tool to ensure that the safety warning signs are bright and eye-catching. Don’t touch the switch with wet hands, otherwise it will cause electric shock; before pressing the switch, make sure it is correct, so as to avoid danger caused by wrong connection; be familiar with the position of the emergency stop button, and make sure that you can press it when you need to use it. Without safety operation training, one can not operate the high-speed machining center, and generally two people are not allowed to operate the high-speed machining center at the same time. If two or more people are required to complete a work, a coordinated signal should be specified in each step of the operation. “Unless the specified signal has been given, do not proceed to the next step of operation. Do not change system parameter values or other electrical settings. If it must be changed, the original value should be recorded before the change, so as to restore to the original adjusted value if necessary.
Bychengcg

Features of precision grinder – computer gong

So what are the characteristics of gantry precision grinder processing?

  1. Taiwan ball screw is equipped on the bed, beam and end milling head, which is driven by servo motor.
  2. The unique cross beam lifting safety interlock device ensures the repeated positioning accuracy of the machine tool.
  3. The side milling head is equipped with V5 gantry milling head, the computer gong processing is equipped with independent lubrication device, the lifting is driven by ordinary reducer, and the frequency control is adopted.
  4. The end milling head of gantry precision grinder is equipped with tx400 heavy gantry milling head, double rectangular guide rail and strong rigidity; the milling head is equipped with ball screw, pneumatic broach device and driven by servo motor.
  5. The general milling / NC milling one key conversion three-axis CNC system of gantry precision grinding machine is programmable and can be operated manually by using the extended panel, which has strong practicability in the actual machining process.

Do not cut off the connection of protective device when overhaul the electrical equipment of large water mill.

Electrical maintenance personnel should wear insulating gloves and rubber shoes to avoid electric accidents. And do not wear metal jewelry and other conductive articles that may lead to false electric shock.

Before overhauling the electrical equipment, pay attention to follow the instructions of the relevant warning plate, and use the appropriate three watt hour meter to confirm that the circuit is open circuit.

When overhauling the electrical equipment of the large gantry grinder, the main power switch must be cut off, and warning signs must be erected, so as to avoid the accidental injury caused by the reactivation of the large water mill without the knowledge of others.

When the motor is activated in the grinding machine, there may be sparks at the contact point of the electrical box, so the machine can not be used in dust, gas explosion and flammable places.

The electric box of large water mill is designed for the safe operation of the machine. No one is allowed to modify the structure and circuit design of the electric box without the authorization of our company.

The operator must be familiar with the position of emergency stop switch and main power activation switch of large water mill. In case of emergency, the machine can be stopped and the power can be cut off at the first time.

Process specification is one of the process documents that stipulate the machining process and operation method of parts. It is written into the process in accordance with the specified form for the machining of mechanical parts under the specific production conditions. The large-scale computer CNC machining center is a kind of CNC machining center with tool magazine and can automatically replace the tool, which can control the workpiece at a certain speed CNC machine tools for a variety of processing operations.

Large computer gong machining center is usually classified by the relative position of spindle and worktable, which is divided into horizontal, vertical and multi axis linkage machining center.

A horizontal machining center: it refers to the machining center with the spindle axis parallel to the workbench, which is mainly suitable for machining box parts.

B vertical machining center: it refers to the machining center with the spindle axis perpendicular to the worktable, which is mainly suitable for processing plate, plate, mold and small shell complex parts. C multi axis linkage machining center, also known as universal machining center, refers to the machining center that can control linkage change through the angle between the spindle axis and the rotary axis of the worktable to complete the machining of complex spatial surface. It is suitable for machining impeller rotor, mould, cutting tool and other workpieces with complex space surface.

After the machined parts are clamped once, the CNC system can control the machine tool to automatically select and replace the cutting tools according to different processes; automatically change the spindle speed of the machine tool, the feed rate of Dongguan CNC machining center, the movement path of the cutting tool relative to the workpiece and other auxiliary functions, and continuously carry out multiple processes such as drilling, countersinking, reaming, boring, tapping, milling, etc Processing.

Because the early CNC system of milling machine does not have the function of function calculation, it is difficult to work out the processing program of function equation curve directly with G code, and the CAD / CAM software (with lower version) usually does not have the function of inputting graph directly from equation, so it is very difficult to process the contour of function equation curve.

The programming method of machining center: the contour composed of simple contour line and arc is directly programmed with G code of NC system. In this paper, the complex outline of three-dimensional curved surface is drawn with CAD / CAM software in the computer. According to the type of curved surface, the corresponding parameters are set, and the NC machining program is automatically generated. The above two programming methods can basically meet the requirements of NC machining.

The process of large-scale mechanical parts processing plant is to change the shape, size, relative position and nature of the production object on the basis of the process, so as to make it into finished or semi-finished products. It is the detailed description of each step and each process,

The specific technical requirements are as follows: ‘

(1) Remove oxide scale from parts.

(2) The unmarked shape tolerance shall meet the requirements of gb1184-80, and the allowable deviation of unmarked length dimension shall be ± 0.5mm. The tolerance zone of casting is symmetrical to the basic dimension configuration of blank casting.

(3) When assembling rolling bearings, it is allowed to use oil heating for hot charging, and the oil temperature shall not exceed 100 ℃. There should be no scratch, scratch and other defects on the surface of parts.

(4) When assembling the hydraulic system, it is allowed to use sealing packing or sealant, but it should be prevented from entering the system. Before assembly, the main fit dimensions of parts and components, especially the interference fit dimensions and relevant accuracy shall be rechecked.

(5) The parts and components to be assembled must have the certificate of inspection department before they can be assembled. Parts must be cleaned and cleaned before assembly, without burr, flash, oxide scale, rust, chip, oil stain, colorant and dust.

(6) Parts shall not be knocked, touched, scratched or rusted during assembly. When fastening screws, bolts and nuts, it is strictly forbidden to strike or use improper screwdrivers and spanners. After tightening, the screw groove, nut, screw and bolt head shall not be damaged. For fasteners with specified tightening torque requirements, torque wrench must be used and tightened according to specified tightening torque. After bonding, the excess adhesive should be removed. The semicircular holes of the bearing outer ring, the open bearing seat and the bearing cover shall not be stuck; the semicircular holes of the bearing outer ring, the open bearing seat and the bearing cover shall be in good contact, and they shall be in uniform contact with the bearing seat within the range of 120 ° symmetrical to the center line, and the machining of Dongguan Mechanical parts and the bearing cover within the range of 90 ° symmetrical to the center line. When checking with a feeler gauge within the above range, the 0.03mm feeler gauge shall not be inserted into 1 / 3 of the outer ring width. After assembly, the outer ring of the bearing shall contact the end face of the bearing cover at the locating end evenly.

In the process of processing large parts, we still need to pay attention to the safety aspects

  1. The cutting tool must be clamped firmly, otherwise it is not allowed to drive.
  2. When moving the worktable and tool rest, loosen the fixing screw first.
  3. When milling various workpieces, especially during rough milling, slow cutting should be carried out at the beginning.
  4. When loading and unloading tools, use copper hammer or wooden mallet to gently hit to prevent tool fragments from flying out and injuring people.
  5. Before work, check the operation of the transmission part of the machine tool, and install the baffle of the machine tool before operation.
  6. The work object should be clamped with pressing plate, screw or special tool. The general wrench is not allowed to add casing, so as to avoid slipping and injury.
Bychengcg

High speed Gong processing requirements

The surface quality standard of high speed computer gong parts

1、 The purpose and action of high speed Gong processing temperature control on formability. The appearance of products, physical properties of materials and forming cycle are significantly affected by die core temperature. In general, it is ideal to keep the core temperature low to increase the injection times. However, the forming cycle related to the shape of the product (core structure) and the type of finished material also depends on the need to increase the core filling temperature.

2、 In order to prevent the temperature control of stress, this is the problem of forming material, the only requirement is cooling rate. The cooling time is short. Even if some parts are hardened and some parts are soft, the stress caused by uneven shrinkage can be avoided. That is to say, proper temperature control can improve the properties of cooling stress.

3、 Temperature control of crystallizing degree adjustment of forming material. High molding temperature is usually required to adjust the degree of crystallization and improve the mechanical properties of crystalline materials such as polyamide, polyacetate and polypropylene.

  1. Computer gong processing fastening parts, check whether the fastening parts loose, damage phenomenon, the way is to find the same specification of metal stamping parts for replacement.
  2. The edge of metal stamping must be ground after a long time of use. After grinding, the edge surface must be demagnetized without magnetism, otherwise the metal stamping is prone to material blocking.
  3. The punch is easy to break, bend and gnaw in the process of metal mold processing. The punch sleeve is generally gnawed. The damage of the punch and the punch sleeve of metal stamping is generally replaced with parts of the same specification. The punch parameters mainly include the size of the working part, the size of the installation part and the length size.
  4. High speed Gong processing hardware stamping parts, such as pressure plate, uniglue, etc., discharge parts, such as stripper, pneumatic top material, etc., during maintenance, check the parts of the relationship and whether there is damage, repair the damaged parts, pneumatic top material check whether there is air leakage, and take measures for the specific situation, such as the replacement of air pipe damage.

Basic program of large computer gong processing

  1. Large scale computer gong processing accuracy requirements, a mold is generally composed of female mold, male mold and mold base, some may also be multi-component module. Therefore, the combination of upper and lower die, the combination of insert and cavity, and the combination between modules all require high machining accuracy. The dimensional accuracy of precision die for machining mechanical parts is often up to μ m level.
  2. The shape and surface of some products, such as automobile panels, aircraft parts, toys and household appliances, are complex. The surface of the shape is composed of a variety of curved surfaces. Therefore, the cavity surface of the mold is very complex. Some surfaces must be treated mathematically.
  3. The production of small batch mold is not mass production, in many cases, only one batch is produced.
  4. There are many working procedures for large-scale computer gong, and many working procedures such as milling, boring, drilling, reaming and tapping are always used in mold processing.
  5. The service life of repetitive production mould is long. When the service life of a pair of molds exceeds its service life, it is necessary to replace the new molds, so the production of molds is often repetitive.
  6. In the mold production of copying process, sometimes there is neither drawing nor data, and the copying process should be carried out according to the real object. This requires high imitation accuracy and no deformation.
  7. Large computer gong processing mold material is excellent, high hardness, the main material of the mold is made of high-quality alloy steel, especially high life mold steel. This kind of steel has strict requirements from blank forging, processing to heat treatment. Therefore, the establishment of processing technology can not be ignored, and heat treatment deformation is also a serious problem in processing. The basic operation of high-speed Gong machining requires that the working performance of high-speed Gong machining center is an important prerequisite for mold manufacturing industry to process mold efficiently and accurately. Driven by drive technology, many different types of high-speed machining centers with innovative structure and excellent performance have emerged. Do not place obstacles around the high-speed machining center to ensure that the working space is large enough; do not splash water or oil on the ground to ensure that the working ground is clean and dry; do not move or damage the warning signs installed on the machine tool to ensure that the safety warning signs are bright and eye-catching. Don’t touch the switch with wet hands, otherwise it will cause electric shock; before pressing the switch, make sure it is correct, so as to avoid danger caused by wrong connection; be familiar with the position of the emergency stop button, and make sure that you can press it when you need to use it.
Bychengcg

Processing copper parts with computer gong

Precision copper processing in our daily life, we often encounter a variety of copper, mechanical parts processing, some products for copper processing technology requirements are very high, the process is not the same, for the processing of product scale is also to have a certain understanding, and then according to the sketch to make mold, so the sketch is very important, in the lamp material copper processing This material is not easy to rust, but also has a long service life. This material is not easy to be cut, and can be made into various shapes. The most important point is that it is conducive to the melting treatment of objects.

And copper alloy is easy to oxidize and change color after pickling. After pickling, copper parts can be immersed in anti tarnishing agent for several minutes, which can effectively prevent copper parts from changing color. The commonly used anti tarnishing agent is ab-712. Take 1 liter working solution as an example, take 70 ml ab-712 anti tarnishing agent, add 930 ml distilled water, stir evenly, and then use it.

BH anti discoloration agent can also be used. BH anti discoloration agent for precision copper parts processing is suitable for anti discoloration treatment of copper and copper alloy chemical polishing parts, copper plating and copper alloy (imitation gold, etc.) parts before coating, anti discoloration treatment of barrel nickel plating parts, composite anti discoloration treatment of silver plating, gold plating and electroplating imitation gold parts after electrolytic passivation, so as to improve its anti discoloration effect. It can also be used for fixation of copper and copper alloy parts after dyeing. It is a new process of chromium free, low pollution and environmental protection.

  1. The polishing solution does not contain chromic acid, which meets the requirements of today’s environmental protection and saves the investment of environmental protection equipment and waste water treatment costs.
  2. The current density of polishing is smaller than that of traditional process, so it not only has low power consumption and long service life of polishing solution, but also is more suitable for surface polishing of large aluminum and aluminum alloy parts.
  3. Precision copper processing has a wide range of applications. CNC machine tools are suitable for processing pure aluminum and various types of aluminum alloys with silicon content more than 2%.

Composition and operating conditions of polishing solution

Concentrated phosphoric acid (specific gravity 1.74) 70% (weight)

Yb-66 additive 30% (weight)

Precision copper processing temperature 55 – 65 ℃, the best 60 ℃

Anode current density, Da 2 – 8 A / DM2 (without stirring)

12 – 20 A / DM2 (stirring)

Voltage 10 – 15 V

Polishing time 3 – 5 minutes

Cathode material lead or stainless steel

Cathode area: anode area 2 – 3:1