Machining and positioning device and machining method for lining holes at two ends of connecting rod

Abstract

The invention discloses a machining and positioning device for lining holes at two ends of connecting rod. The positioning device comprises a pressing mechanism, a bottom plate, a V-shaped support(10)fixed on the bottom plate, a floating support(9), a first bottom support(7), a second bottom support(8), and a side positioning block(1), the V-shaped support(10) is used for supporting and positioning the small head end of the connecting rod to be machined, the floating support(9) is arranged at the small head end of the to-be-machined connecting rod, the first bottom support(7) and the second bottom support(8) are arranged at the large head end of the to-be-machined connecting rod, the side positioning block(1) is arranged on one side of the large head end of the connecting rod to be machined, and the pressing mechanism presses and positions the large head end and the small head end of the connecting rod to be machined. The machining and positioning precision of the connecting rod sizehead hole can be improved, the accumulative error and the clamping and machining deformation are effectively avoided, the connecting rod large-head hole is ensured, the size and shape position precision of the small-head bushing hole are high, the precision is stable, the consistency is better controlled, and a good effect is achieved.

Description

technical field [0001] The invention belongs to the technical field of mechanical processing, and relates to a processing positioning device and a processing method for bushing holes at both ends of a connecting rod. Background technique [0002] The connecting rod is a key high-load moving part in the core moving parts of the engine. With the high-speed, high-power, and high-reliability performance requirements of the engine, the size, shape, position accuracy, and consistency of the big head hole and the small head bushing hole of the connecting rod The requirements are becoming more and more stringent. How to ensure the stability and consistency of the size, shape, position accuracy and control accuracy of the big end hole of the connecting rod and the bushing hole of the small end, the process method is the key link. [0003] The processing methods used in the processing of the original big head hole and small head bushing hole of a certain type of engine connecting rod ...

AI Technical Summary

Problems solved by technology

[0011] 1. After the positioning pin is pulled out, only the side positioning block is positioned, and the positioning is unreliable; there is a fit gap between the positioning pin and the positioning pin hole, and between the positioning pin and the small head hole of the connecting rod, and the accumulated error affects the consistency of the center distance between the big and small head holes of the connecting rod. Sex, even out of tolerance

[0012] 2. The wear of small head positioning pins and fixed pin holes also causes poor consistency in the size of the center distance between the big and small head holes of the connecting rod, and even out-of-tolerance

[0013] 3. There is a height difference H between the end faces of the big and small ends of the connecting rod (see the original method diagram), and the height difference of each connecting rod is about 0.04-0.1mm. The fit is very good, but there is deformation when clamping, resulting in inconsistent or out-of-tolerance parallelism between the small head hole of the connecting rod and the big head hole in the horizontal and vertical directions, and inconsistent or out-of-tolerance parallelism between the end of the big head hole and the center of the big head hole

[0014] 4. Although a torque wrench is used for manual clamping, the working state of the person will affect the real torque of the torque wrench, thereby affecting the parallelism of the connecting rod size head hole and the verticality of the big end face

[0015] 5. The fine boring blade of the small head bush hole wears quickly. In order to ensure the surface roughness of the small head hole Ra0.4, the blade needs to be replaced once when processing 60 small head bush holes.

[0016] 6. Clamping is difficult, and positioning pins are often difficult to install and remove, and the auxiliary processing time is long

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