Extrusion forming process of step hole in head seat of hydraulic jack

Abstract

The invention relates to an extrusion molding process for a step hole of a head seat of a hydraulic jack. The specific steps include: S1, blanking a plate body to obtain a blank disk material, and reserve a central hole when blanking; S2, extruding and flanging, The first punch of the 200T hydraulic press applies pressure to one end surface of the blank disc material for cold extrusion, and the upper end of the rough disc material is flanged after extrusion to obtain the first intermediate piece; S3, extruding the stepped hole, The second punch of the punching machine applies pressure to the end surface of the blank disc material with flanging for cold extrusion, the diameter of the second punch is smaller than the diameter of the first punch, and the diameter of the second punch is larger than the central hole in step S1 diameter, and form a step hole with the center hole to obtain the second intermediate piece; S4, extrude the center hole, the second punch and the third punch adopt a coaxial mutual fitting structure, and the diameter of the third punch is larger than that of the step The diameter of the center hole in S1. The invention has the advantages of avoiding stress concentration on the hole wall and ensuring the structural strength of the plug seat.

Description

Technical field: [0001] The invention belongs to the field of hydraulic jack production, and specifically, the present invention relates to an extrusion molding process of an oil pressure jack top head stairs. Background technique: [0002] The rubber pad is provided in the head of the hydraulic jack, and the rubber pad is directly in contact with the product (vehicle) that needs to rise. The product on the head seat is tapered by the hydraulic cylinder, and the head holder has a step hole connected to the base of the hydraulic jack. . At present, there is a technical defect in the production of hydraulic jacks: [0003] 1. The step-by-step hole of the head seat is thermocompression molding machine, but during the hot pressing process, the residual pressure stress layer is introduced in the hole wall, and the hot pressing process is extremely easy to generate thermal stress in the head block internal structure. It is easy to generate fatigue cracks and fatigue breaks in the hole ...

AI Technical Summary

Problems solved by technology

[0003] 1. Use a hot-press forming machine to perform one-time hot-press forming on the step hole of the plug seat. However, during the hot-press forming process, a residual compressive stress layer is introduced into the hole wall. The hot-press process can easily cause thermal stress on the internal structure of the plug seat. It is very easy to produce fatigue cracks and fatigue fractures on the edge of the hole and the wall of the hole, especially for the plug seat of the hydraulic jack, which requires extremely high structural strength, so the hot pressing forming process cannot meet the structural strength of the plug seat;

[0004] 2. Using cold extrusion or twisting, the twisting process will cause elastic-plastic deformation of the hole wall, and the pressure required for cold extrusion is relatively high, and a high temperature rise is generated during the extrusion process. The extruded plug seat The deformation resistance is high, the calorific value is large, and the punch bears high temperature. Long-term use affects the service life and extrusion effect of the punch. The center hole not only has shrinkage cavity, but also has a coarse structure.

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