Crank arm machining positioning clamp and machining method

Abstract

The invention discloses a crank arm machining positioning clamp and a machining method. By arranging a base, a positioning reference block and a pressing block; the included angle between the first side face and the second side face of the positioning reference block is equal to the included angle of reference planes of a crank arm to be machined, during machining, the first side face of the positioning reference block is attached to the end face of the pressing block, the reference planes of the crank arm to be machined are attached to the second side face of the positioning reference block,the positioning reference block is fixed to the base through the pressing block, the connecting line between the circle centers of two installing holes in the crank arm to be machined is parallel to the end face of the pressing block, the crank arm to be machined is fixed to the base through a bolt set, the positioning reference block is used for positioning the reference planes of the crank arm to be machined, the side faces of the positioning reference block can be rapidly positioned, the problem that the crank arm machining clamping position of is hard to determined is solved, and meanwhile, the machining precision of the crank arm is improved; meanwhile, errors caused by secondary clamping are omitted, the machined crank arm better meets the requirement for the drawing design technology, and therefore the purposes that the machining efficiency of the crank arm is improved, the machining precision of the crank arm is improved, and the production, material and labor costs are loweredare achieved.

Description

Technical field [0001] The invention belongs to the field of mechanical design and manufacturing, and relates to a turning arm processing positioning fixture and a processing method. Background technique [0002] During the machining of the crank arm, when clamping the crank arm, it is necessary to mill a datum plane on the plane perpendicular to the plane of the worktable that forms an angle of 12.511° with the center of the circle through the arm installation circular hole as a reference; Before that, you need to find the line connecting the two centers; because there is no point on the crank arm that can be used as a reference, you can only equip the crank with a PVC cylinder to find the parallel line connecting the two centers; and the crank is in use In the process, the circles of ￠90 and ￠50 will wear out and deform. Each arm to be processed needs to be equipped with a corresponding PVC cylinder, which cannot be reused; this not only causes waste of PVC bars, but also reduc...

AI Technical Summary

Problems solved by technology

[0002] During the processing of the crank arm, when clamping the crank arm, it is necessary to mill out a datum plane on the plane with an angle of 12.511° with the plane perpendicular to the center line of the round hole passing through the crank arm installation hole as a reference; Before that, it is necessary to find the line connecting the two centers; since there is no point on the crank arm that can be used as a reference point, the arm can only be equipped with a PVC cylinder to find the parallel line connecting the two centers; and the crank arm is used During the process, the circles of ￠90 and ￠50 will be worn and deformed, and each crank arm to be processed needs to be equipped with a corresponding PVC cylinder, which cannot be reused; this not only causes waste of PVC bars, but also reduces processing efficiency. And it consumes a lot of material resources, manpower and financial resources

[0003] The use of PVC cylinders to align the clamping position of the crank arm will reduce the machining accuracy of the crank arm; in addition, two clampings are required. Because the benchmarks of the two clampings are inconsistent, it is easy to cause deviations in the processing of the crank arm, resulting in The hole processing size is inconsistent, and the precision is difficult to meet the process requirements of the drawing

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