Copper casting is to melt copper into liquid and inject it into the cavity of the die casting mould with high pressure and high speed. After the copper water is cooled and the mould is opened, a formed product can be obtained. However, copper ingots are usually used instead of scrap copper. There are too many impurities in waste copper, which will affect the work of die casting.

Copper casting of pump valve

What are the functions and characteristics of copper castings in life

1. Copper casting has a very good durability, which is not the performance of many castings.

2. Because of the strong stability and oxidation resistance of copper, copper castings are not rusty and corrosion resistant. Because of this, many decorative products are made of copper castings, which can keep the color from fading.

3. Copper casting is very, through many tests, it has been proved that copper products have good seismic resistance, and the resistance to wind pressure and weathering is amazing. So if we use copper casting, we will add. At the same time, the weight of copper casting is lighter, which can reduce the burden on people and reduce the risk.

4. Because the toughness of copper is very good, so it determines its plasticity, can be designed into a variety of shapes, ductility is particularly good. Because of this, copper castings can be used for recycling, saving materials, and widely used. Because of this characteristic of copper, it also determines its creativity, which is very good and can be transformed at will.

5. As copper is lighter, it is more convenient for us to use, and there is no pressure for installation or maintenance.

The solid structure of the copper casting part of the pinion has 20 teeth. Because the larger end face is the parting surface, there are duck web shaped fragments between multiple teeth of the pinion casting, there are flash burrs on the edges of the teeth, and there are four burrs on the four reinforcing ribs of the gear end face. At the initial stage of processing, the company adopts manual deburring. The order of deburring is as follows: first, use the file between teeth to remove the duck web shaped burr between teeth and the burr on the edge of teeth, then use the end file to remove the burr on the end pouring mouth, and then use the sandpaper to polish and brush to remove the debris. However, in the actual deburring process, due to the better toughness of the web like debris between the teeth, the debris burr turns over and sticks to the outer edge of the teeth after the teeth are reduced. When the end face is reduced, the debris burr turns back to the teeth again, which is difficult to remove, time-consuming and laborious. The repair rate is relatively high, which increases the production cost of the pinion.

In order to improve the machining efficiency, first of all, we should consider how to reduce the generation of burr and the location of the burr. Second, we should consider the method of deburring and the equipment and tools from the aspect of machining efficiency. As the requirements of die casting process and gear structure have been determined in the order, the only way to improve productivity is to improve deburring.

Design of copper castings:

1. Considering the problem of wall thickness, too much thickness difference will affect the filling.

2. Considering the problem of demoulding, this is very important in the practice of die casting. In reality, such problems often occur again. Therefore, we should pay attention to the setting of draft angle and the calculation of dynamic and fixed mold demoulding force. Generally, the draft angle is 1 to 3 degrees, usually considering the smoothness of demoulding. The outer draft angle is smaller than the inner draft angle, and the outer draft angle is 1 degree, while the inner draft angle is about 2 to 3 degrees.

3. When designing, the problem of mold design should be considered. If there are multiple positions of the core pulling position, try to put them on both sides as much as possible, and do not put them on the lower position of the core pulling position. In this way, the problem of the bottom core pulling will easily occur after a long time.

4. Some die-casting parts may have special requirements for appearance, such as fuel injection, powder spraying, etc. at this time, the structure shall avoid the important appearance position to facilitate the setting of gate overflow groove.

5. In the structure, try to avoid the complex structure of the mold, such as having to use more than one core pulling or spiral core pulling.

6. For parts requiring surface machining, pay attention to the appropriate machining allowance in part design, not too much. And the pores inside will be exposed, not too little, otherwise the black skin of rough and fine positioning processing has not been dried, you will wait to make sparks on the mold, then how much is left, the amount should not be more than 0.8mm, so the processed surface can hardly see the pores, because there is a hard layer of protection.

7. Another is to pay attention to the selection of materials. Whether to use ADC12 or A380 depends on the specific requirements.

8. Copper alloy has no elasticity, so it only needs to be matched with plastic.

9. Generally, deep holes cannot be made! In the opening of the mold, only a few holes are made, and then after processing.

10. If it is a thin-walled part, it should not be too thin, and the stiffener should be used to increase the bending resistance. Because the temperature of copper casting is about 800 ℃. The die life is generally short, and it is only about 80K when it is used as the motor shell.