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In China, the amount of conventional energy resources is only 60% of the world average level. In order to meet the growing energy demand, it is necessary to accelerate the development and utilization of new energy. At present, the 9% share of new energy in the energy structure is relatively low compared with the developed countries in the world, and there is still a lot of room for development.

Although the latest statistics of 2008 have not been released yet, the proportion of China’s new energy production in the overall energy structure will exceed 9% based on the data from various aspects, especially the growth rate of China’s new energy production and consumption in the past 10 years.

2008 is an extraordinary year for China’s energy work. Affected by the changes of the world macro-economic situation and natural disasters, the supply and demand of energy has experienced a roller coaster like operation from “tight supply” at the beginning of the year to “demand slowing down” at the end of the year. Authoritative experts pointed out that the easing of the tense situation of energy supply and demand does not mean that China’s energy demand has dropped significantly, nor does it mean that China’s energy supply can achieve absolute self-sufficiency. Therefore, the task of developing new energy is still urgent. Compared with the level of developed countries, 9% of new energy in China is still at a relatively low level.

In 2007, China produced 2.35 billion tons of standard coal, of which coal accounted for 76.6%, oil accounted for 11.3%, natural gas accounted for 3.9%, and other unconventional energy accounted for 8.2%; while the total energy consumption in this year was 2.66 billion tons of standard coal, including 69.5% of coal, 19.7% of oil, 3.5% of natural gas and 7.3% of unconventional energy. In terms of total amount, there is still a gap in energy consumption in China. From the structural analysis, in China’s energy structure, the dominant position of coal has not changed. Although the development speed of new energy is fast, its proportion is still too small.

China has a long way to go in developing new energy, whether in terms of structure or total demand. First of all, the development of new energy is an effective guarantee to maintain rapid economic growth. From 2003 to 2008, the average annual growth rate of China’s GDP is close to 10%. In order to maintain the stable and sustainable development of economy, we must have strong energy guarantee. Throughout China’s resource reserves, the total amount is large and the per capita share is small, so it is difficult to form a sustainable support only relying on traditional energy.

Secondly, the development of new energy is an effective way to alleviate environmental pressure. Compared with traditional energy, new energy has the characteristics of less pollution and high efficiency. Vigorously developing new energy will help to reduce economic losses caused by environmental damage and achieve the goals set in the eleventh five year plan.

Third, the development of new energy is an effective means to ensure the safe supply of energy. Energy security is an important part of a country’s economic security and an important barrier to ensure the independent and healthy development of a country’s economy. At present, China has to import a part of its oil every year, and its dependence on foreign countries is relatively high. To ensure the safe supply of energy, we must adhere to the diversified strategy, and vigorously developing new energy is the concrete embodiment of this strategy.

Fourth, the development of new energy is a powerful weapon to solve the dilemma of unbalanced regional development in China. There is a big gap among regions in China, which is unfavorable to the sustainable development of economy and society. The development of new energy in the vast western regions and remote rural areas not only improves people’s livelihood, but also promotes economic development.

Fifth, it is feasible to develop new energy. With the improvement of technical level, the cost of new energy development has dropped sharply, and the cost of some new energy has been close to or even lower than that of conventional energy.

The reporter interviewed the national energy administration and relevant people in the industry. The unanimous judgment is that the development trend of China’s new energy will, on the whole, maintain a sustained and rapid development momentum and have a bright future.

From the perspective of policy environment, the recently concluded energy work conference has determined the work direction with the theme of structural transformation, which indicates the arrival of a new era of new energy industry. Both the promulgation of new energy and renewable energy planning and the implementation of the new energy law in the future have brought unprecedented opportunities for the development of new energy.

From the perspective of investment, international capital is optimistic. Even in the context of the international financial crisis, investment in the field of new energy will still become the hot spot of capital pursuit. Under the influence of policy guidance, domestic capital will follow suit one after another. The continuous rise of new energy sector in A-share market is sufficient evidence.

From the perspective of the internal structure of new energy, the priority development direction in the future is still wind energy, solar energy and nuclear energy with high technology maturity and economic feasibility. Economic feasibility is an important bottleneck restricting the development of new energy, which will be solved gradually with the improvement of China’s technical level.

With the development of society, gold casting technology has been greatly improved. In the production process, it also reduces the environmental pollution, improves the working environment, improves the production technology and level, which is of great help to the development of the casting industry, so as to promote the development of the automobile industry. The domestic and international markets have more and more stringent requirements on the quality and cost price of automobile forgings, such as draft angle, weight tolerance, size, machining allowance, etc., and the price is not ideal, but the batch is large. In order to meet the needs of the market, this paper analyzes the process and repeated practice, and finds an ideal process, which is of great significance to the production of similar products.

Introduction of products and determination of process plan

The arm body is a part used on the brake pump of a heavy vehicle, and the structure is shown in Fig. 1. There are several difficulties in forging: (1) the draft angle is small, only 3 ° outside and 5 ° inside, while the ejection device only has one place in the ∮ 62 hole; (2) the machining allowance is small, only boring and broaching are used for ∮ 62 and square groove of 23.2mm; (3) 10 – ∮ 6.2 * 5 these 10 nails are difficult to fill, and the location requirements are high, and the root fillet of the nails is r0.2, which makes the die wear faster and easy to bump and cause deformation in the production process.

Determination of process plan

In order to adapt to mass production and improve efficiency, we have determined the following processes: (intermediate frequency furnace) heating / (cross wedge rolling) / (25000kN hot die forging press) bending / pre forging / final forging / (3150kN double point press) punching / trimming / normalizing / shot peening / precision pressing. In the technological process, two pieces at a time are used for heating billet, the handle of the part is long and thin, and the blank making efficiency of single piece by free forging is low. The cross wedge rolling billet (as shown in Fig. 2) is adopted and cut into two pieces on the rolling mill at the same time. Because the cross section of the parts changes greatly, it takes two wedges to complete from ∮ 55 to ∮ 23, so it is difficult to process and repair the rolling die.

In addition to ensuring the size of the head and shank, it is more important to correct the position of the 10 nails, the fillet of the root and the bending of the handle. Therefore, two standard platens with 5 holes are used to ensure the position of nails and the root fillet, and improve the service life of forging die.

Key points of mould design and manufacture

Generally, the bending die design only considers that the shape of the extruded blank is consistent with that of the forging. Due to the large difference in the thickness between the big end and the handle of the arm body, the handle of the bending billet will be suspended when it is put into the pre forging die. During the pre forging, the transition between the handle and the big head will be folded. Due to the suspension of the handle of the bending billet, the metal flow in this part is too large.

The advantages of CNC machine tools are as follows:

1. Processing efficiency, saving processing time.
2. Work intensity. After the workers have finished programming, they can go to drink tea after the first piece is qualified.
3. Reduce the number of waste products. As long as the first piece is qualified, the processed parts will generally be qualified.
4. High safety, the farther the workers are from the processing equipment, the lower the probability of accidents.

For effective metal cutting, machining materials, cutting tools and cutting conditions are the three main factors. These determine the processing time, tool life and machining quality. Cutting conditions must be selected reasonably for economical and efficient processing methods.

The three elements of cutting conditions: cutting speed, feed and cutting depth directly cause damage. With the increase of cutting speed, the point temperature will rise, resulting in mechanical, chemical and thermal wear. If the cutting speed is increased by 20%, the tool life will be reduced by 1 / 2.

Back feed conditions and tool wear are kept to a minimum. But feeding behind, cutting temperature rise, wear. It is less than the effect of cutting speed. Cutting depth has no effect on cutting speed and feed, small cutting depth, but cutting material in hardened layer will also affect tool life.

According to the user’s processing material, hardness, cutting conditions, material selection, feed and cutting depth, the cutting speed is used.

Based on the selection of the most suitable process conditions, these factors are selected. Regular life and stable wear are the most ideal conditions.

However, in practice, the selection of tool life and tool wear, through machining size, surface quality, noise reduction, heat and so on. Under certain processing conditions, it is necessary to study CNC machining according to the actual situation. Difficult to machine materials such as stainless steel, heat-resistant alloy, can use coolant or choose a good rigid blade.

Reasonable selection of cutting tools

1。 Rough rotation, should choose high strength, good durability knife, in order to meet the large car turning, feedback.

2。 The essence of automobile is to select high precision, durable and good cutting tools to ensure the machining accuracy.

3。 Reduce the conversion time and knife convenience, should try to use machine knife and machine clip blade.

Select fixture

1。 General fixture should be selected to clamp workpiece as much as possible, and special fixture should be avoided;

2。 The coincidence of parts positioning datum reduces the positioning error.

Determine the processing route

Machining path is the part of tool path and direction relative to each other in the process of exponential control.

1。 It should be able to meet the requirements of machining accuracy and surface roughness;

2。 Shorten the processing route as far as possible and reduce the idle travel time of the tool.