Special inspection device for measuring perpendicularity of end surface of big-end hole of connecting rod

Abstract

The invention relates to a special inspection device for measuring perpendicularity of end surface of a big-end hole of a connecting rod. The special inspection device comprises a big-end hole locating mandrel assembly, a mandrel loose piece telescoping mechanism and a dial indicator measuring assembly, wherein the big-end hole locating mandrel assembly comprises a mandrel main body, a mandrel loose piece and an elastic retainer ring; the mandrel main body is used for locating the big-end hole of the connecting rod; the mandrel loose piece is clamped on the mandrel main body by the elastic retainer ring; through rotating a knurled nut, upper and lower wedge blocks are driven to approach each other by a double end stud; during acting upon two steel balls, wedge surfaces of the two wedge blocks move outward to push the mandrel loose piece to overcome the resistance of the elastic retainer ring, so that the mandrel loose piece is tightly expanded at the surface of a connecting rod inner hole; a dial indicator head rotated around the mandrel main body is in contact with the end surface of the big-end hole so as to measure variation of the end surface in each position, so that the perpendicularity of the end surface is accurately and rapidly measured; and the special inspection device for measuring the perpendicularity of the end surface of the big-end hole of the connecting rod, provided by the invention, has the advantages that convenience in inspecting operation is achieved, intuitional inspected data are obtained and requirements of repeatability and reproducibility can be satisfied.

Description

technical field [0001] The invention relates to a checking tool for a connecting rod, in particular to a special checking tool for measuring the perpendicularity of the big end of the connecting rod to the axis of the big hole. Background technique [0002] In the existing production technology, the usual measurement methods for the verticality of the end face of the connecting rod include: the detection method of the connecting rod pneumatic measuring instrument, and the detection method of the fixed-size mandrel. a. Pneumatic measuring instrument detection method, place the big hole of the connecting rod on the detection mandrel, the end face of the connecting rod is in close contact with the big head gasket, the computer displays the maximum value of the verticality after scanning, but it cannot show which phase the verticality is in The angle is the largest, the measurement data has no guiding value for fixture debugging, and the investment in measurement equipment i...

AI Technical Summary

Problems solved by technology

a. Pneumatic measuring instrument detection method, place the big hole of the connecting rod on the detection mandrel, the end face of the connecting rod is in close contact with the big head gasket, the computer displays the maximum value of the verticality after scanning, but it cannot show which phase the verticality is in The angle is the largest, the measurement data has no guiding value for fixture debugging, and the investment in measurement equipment is large; b. The fixed-size mandrel detection method, in order to eliminate the influence of the fit gap between the mandrel and the inner hole of the connecting rod on the measurement data, the mandrel is generally made with the connection The large end hole of the rod has a small interference fit, and two parallel planes are symmetrically milled on the cylindrical surface of the mandrel. When testing, the connecting rod and the connecting rod cover need to be disassembled, and the connecting rod and the connecting rod cover should be closed after putting the mandrel in. And tightened to the specified torque, the measurement efficiency of this method is low. Due to the existence of positioning error of the connecting rod bolt hole, after the connecting rod cover is closed and tightened, there is a slight misalignment at the end surface of the connecting rod and connecting rod cover. Minor misalignment affects measurement accuracy

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