Can the workpiece of the thin-walled flywheel housing be used as a quick-change fixture?


Release time:

2022-07-19

The flywheel housing is a key component of the engine. It is connected to the engine through one side of the gear chamber surface, and connected to the transmission through one side of the basin port, thereby realizing the effective connection between the engine and the transmission. Through its variations, the same engine can be carried on different cars. The flywheel shell has a complex shape, with a porous system, thin walls and a basin shape.

The flywheel housing is a key component of the engine. It is connected to the engine through one side of the gear chamber surface, and connected to the transmission through one side of the basin port, thereby realizing the effective connection between the engine and the transmission. Through its variations, the same engine can be carried on different cars. The flywheel shell has a complex shape, with a porous system, thin walls and a basin shape.

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The casting processing mainly includes the mating surface with the gear chamber and its hole system, the hole system on the side of the basin mouth and the hole system on the side of the basin, the peripheral surface of the basin structure and its hole system. Because the single size of the workpiece is too large, the unmarked wall thickness is 6mm, the rigidity of the workpiece is poor, it is easy to deform during the processing, and it is a difficult part to process. Therefore, the processing of the flywheel housing has strict accuracy requirements. The manufacturing process of the flywheel housing takes the ductile iron flywheel housing and metal mold casting as an example. After casting, artificial aging treatment, shot peening treatment and surface coating treatment are carried out to enter the processing process. Due to the wide variety of flywheel housings, it is necessary to reasonably design the fixture to ensure the versatility of the fixture, or to shorten the time required for fixture switching as much as possible.

After summarizing and analyzing the relationship between the pin hole of the all-iron flywheel housing and the crankshaft hole in the production, a fixture for fast switching during the processing of the flywheel housing is designed. The main body of the fixture is the bottom plate, and other parts on the fixture are directly or indirectly mounted on the bottom plate. The bottom plate is designed with multiple sets of nail holes (with countersunk holes) and a central hole for positioning and connecting with the machine tool worktable.

Design of locating pin seat:

The positioning pin seat is used to determine the flywheel housing on the bottom plate.position of the body. It is connected to the bottom plate by bushings, pins and hexagon socket head screws. Three sets of bushings are assembled on the locating pin seat. The bushing passes through the dowel seat and its lower end extends into the base plate. Only one set of bushings is fitted with dowel pins during clamp operation.

design of stamping mechanism:

There are several sets of pressing mechanisms on the bottom plate. The pressing mechanism includes a hexagon socket head screw pressed on the upper surface of the bottom of the flywheel shell basin, a pressing support block and a flange screw sleeve. A compression support block is installed on the bottom plate to support the workpiece, and a flange screw sleeve is installed under the bottom plate, which is mainly used to indirectly complete the connection between the compression screw and the bottom plate. During the operation, the compression bolt passes through the workpiece (through the nail hole at the bottom of the flywheel shell basin) and the compression support block, and then the lower end of the screw is threaded to the bottom plate through the flange screw sleeve to complete the compression of the workpiece.

Design of locating pin and pressing block:

The positioning pin retains the structure of the ordinary cylindrical positioning pin and the diamond positioning pin. At the same time, a threaded hole is added at the end of the workpiece machining hole for the connection between the positioning pin and the pin puller.

When the flywheel housing of one specification needs to be replaced with another specification after processing, the positioning pin and its position may need to be adjusted. When adjusting, just screw the front thread of the pin puller into the center screw hole on the upper part of the positioning pin, press the pressure rod of the pin puller, and pull the positioning pin out of the bushing.

The pressing support block is used to support the flywheel housing, and this position is also the pressing point of the flywheel housing during operation. Its shaft has a through hole for pressing the screw in; the diameter of the base protection block is the same as the diameter of the compression support block, and its height is lower than the height of the compression support block, but the same as the height of the positioning pin seat. Its main function is to protect each positioning support point on the board from damage during operation.