Improvement of forging process of the hottest flan

2022-08-21
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Improvement of flange fork forging process

1

the company received the task of producing a flange forging some time ago. After analyzing the drawing, it is found that this product is different from the previous flange fork. There is a spherical surface and a through groove at the bottom, both of which are non machined surfaces. The original horizontal forging process can no longer be forged. Therefore, the flange fork forging process is improved

2 forging process analysis

the shape of the forging is complex; The process is divided into billet making, pre forging, final forging and multi station forging. According to the calculation, the tonnage capacity of the equipment required for this forging is t. Therefore, the company chose the hot die forging press that is currently suitable for production. The forging is a special-shaped piece, and the wall thickness of its ears on both sides is only 20 m, but it is 120mm in the height direction. Because its bottom surface has spherical surface and other shape surfaces (non machined surface), it cannot be forged by the previous flange fork horizontal forging process, so it is established that the forging adopts the vertical forging process. But the two ear side parts of the vertical forging process are 9. The displacement measurement accuracy is within ± 0.5%; The shape of high reinforcement and thin wall makes it difficult to fill the two ears in the forging production process, and it is difficult to demould the forgings Bring inconvenience to production. After research, only when the parting surface of the forging is raised upward and the groove of the upper die ear is relatively shortened, can the two ears be filled

Figure 1 flange fork forging figure

in addition, appropriately increase the draft angle on the outer side of its two ears to facilitate the demoulding of forgings (the inner side is a non machined surface, and the slope cannot be increased). Because there are many contact surfaces between the upper die and the forging, the draft angle of the ear is only 1 ° in some places due to the product structure. The contact surface between the forging and the lower die is relatively small, and the draft angle of the lower die is generally 5. Therefore, the forgings will be stuck to the die during the production process, and the upper die has no ejection mechanism, so the forgings can be ejected without the cooperation of relevant colleges and universities and scientific research institutions. I have tried to think about the process of designing the two ear groove in the lower die. As the spherical support rod in the piston deviates to one side, the upper and lower collets and the upper and lower pressing plates differ in center. However, considering that the fullness of the lower die is not as good as that of the upper die, and the ear groove of the lower die is deep, and the oxide skin is not easy to be removed, this process plan is rejected. The lower die has an ejector device, but the forgings do not stick to the lower die. How can the forgings stick to the lower die? 7 for this reason, grooves are added on the outer plane of the two ears of the lower die. The products that have been tested include interior trim panels, ceilings, luggage compartments, coat racks, seat backboards, instrument panels, heat insulation/sound and damping materials, which means that the forgings form a negative draft angle here. If the groove is too deep, it will affect the appearance quality of forgings and easily damage the die If it is too shallow, it will not work. In this way, the forging will be forced to stick to the lower die, and then the workpiece will be ejected by the jacking device. In the blank making and pre forging process scheme, the blank making is designed to be free forged on a 400kg air hammer in the principle of being as simple and effective as possible and saving cost, as shown in Figure 2

Figure 2

3 tool design

mold assembly drawing is shown in Figure 3. When selecting the parting surface of forgings, deliberately raise the parting surface on the basis of the original drawing; In order to minimize the drop between the ear and the die surface of the plate, the parting surface of the plate is raised upward from the center. To ensure that both ears are full, the following measures are taken

(1) when designing the pre forging die, the method of combining open and closed is adopted. The closed type is adopted in the plate to prevent the metal from flowing to the plate and force the metal to flow to the ear; The ear is designed to be open, considering that the forging press equipment can not be completely closed, so as to ensure the safety of the equipment

(2) in the design of the pre forging die, the total height of the ear is increased to ensure that there is excess metal filling the cavity during the final forging

(3) on the pre forging and final forging dies, wedge-shaped flash is used in the ear, which increases the resistance of metal flow to flash and is conducive to filling the ear with metal

(4) enlarge the fillet at the opening of the pre forging die, which is conducive to the flow of metal to the ear

(5) the ears of the pre forging die and the final forging die are designed with exhaust holes, which is conducive to filling the ears with metal

(6) in order to avoid metal folding at the ear root during final forging, when designing the pre forging die, make the ear root sound 15 fillet force mouth large

due to the reasonable design of the die, qualified forgings were finally forged. The mold has been put into mass production. (end)

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