Compound fixture for processing matched seam allowance on upper body of motor car bogie axle box

Abstract

The invention discloses a compound fixture for processing a matched seam allowance on the upper body of a motor car bogie axle box. A rough machining bearing hole serves as a locating surface; when a workpiece is installed, a movable bottom plate in a movable fixture is placed on an adjusting fixture; the movable fixture and the adjusting fixture are precisely located by two movable bottom plate locating rods; the workpiece is accurately located on the movable fixture by two workpiece locating rods; after the workpiece is located, the workpiece is fixed by a compression screw; then the movable fixture is turned over to be installed on a fixed support; a space is formed between the top surface of the compression screw and a fixed bottom plate; and after the movable fixture is fixed and installed, the matched seam allowance on the workpiece faces upwards. Thus, the workpiece is positioned on a processing center, one-time clamping can be used for milling the matched seam allowance, a lower joint surface and the lower surface of a connected lug and used for profile machining of a connecting hole to ensure that the thickness between the matched seam allowance and two sides of a bearing hole is even, the working procedure quality good rate of the workpiece is 99.8%, and the clamping regulation time is shortened by 105-120 seconds as compared with the prior art.

Description

Technical field: [0001] The invention relates to a jig for processing the upper body of the axle box of a motor vehicle bogie, in particular to a fixture for processing the upper body of the axle box of a motor vehicle bogie. Background technique: [0002] On the train, the axle box of the train bogie is similar to the connecting rod on the diesel engine. It is composed of the upper body of the axle box and the lower body of the axle box. It is connected by butt joints and fasteners, the upper body of the axle box is as figure 1 , figure 2 As shown, it includes a bearing shell 11, a semicircular bearing hole 12, a connecting lug 13 and a matching notch 14, the fitting notch 14 is arranged between the connecting lugs 13, and the length L of the fitting notch 14 is 250 mm, semicircular The diameter of the bearing hole 12 is 240 mm, the minimum wall thickness of the matching notch 14 is only 5 mm, the length dimension L1 of the connecting lug 13 extending outward from the fi...

AI Technical Summary

Problems solved by technology

[0008] First, when machining the matching spigot 14 and the lower joint surface A of the matching spigot and the lower plane B of the connecting lug seat with a machining center, the upper end surface of the bearing shell 11 and the connecting lug seat 13 is used as the positioning reference, and This benchmark is inconsistent with the casting benchmark. The surface quality of the upper end surface of the bearing shell 11 and the connecting ear seat 13 is very poor. Common defects such as shrinkage cavities, shrinkage porosity, and fleshiness in casting are concentrated in these parts, so they are used as the mating seam 14 for processing. The stability of the positioning datum is relatively poor. During the processing, the matching seam 14 is prone to edge deviation. According to the statistics of the applicant, the ratio of the eccentricity of the semicircular bearing hole 12 relative to the mating seam 14 is more than 20%. The authenticity of the parts rate is not high

[0009] Second, due to the relatively high proportion of the offset side of the semicircular bearing hole 12 relative to the mating notch 14, the machining allowance of the subsequent semicircular bearing hole 12 is increased and uneven, which increases the difficulty and accuracy of the subsequent boring process

[0010] Through the analysis of the existing mechanical processing technology, the applicant believes that the existing mechanical processing technology is not reasonable enough and should be adjusted. Through the test, the applicant explores a reasonable mechanical processing process route, and the finished product rate of mechanical processing reaches 99% to 99.8%.

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