Sheet metal flat-bottomed punch riveting connection process with protruding inward-turning rivets in the center

Abstract

Flat-bottom punching riveting process with a raised inward-turning rivet in the center. Before the flat-bottom punching riveting connection starts, use a blank holder to press the upper and lower sheets on the lower mold. The upper surface of the lower mold is smooth and smooth. There is a rivet in the center of the circle, and there is a bulge in the center of the rivet. The bottom of the rivet is turned inside out, and the upper end of the rivet is in contact with the punch; The upper and lower panels are deformed, and the materials of the panels cannot flow outward due to being pressed by the blank holder ring. During the deformation process of the upper and lower panels, the materials of the panels will flow into the rivets, and the materials of the lower panels will flow into the rivets. The flow of material will squeeze the material of the upper sheet into the rivet, so that the middle of the lower sheet will protrude upwards to form an inner convex point and embed it into the upper sheet to form a mechanical lock, so that the upper and lower sheets are connected together, and the lower sheet The lower surface of the plate is always flat, and the invention has the advantages of reliable connection quality and high connection strength.

Description

technical field [0001] The invention belongs to the technical field of plate connection, and in particular relates to a plate flat-bottom punching riveting connection process with a protruding inward-turning rivet in the center. Background technique [0002] There are many problems in the traditional plate connection method when connecting aluminum alloy plates, but the rivets will penetrate the upper plate during the connection process, causing damage to the upper plate and causing inconvenience to sealing and anti-corrosion. In addition, there is a protrusion on the other side of the punching riveting connection point, which seriously affects the appearance. [0003] In recent years, someone has proposed the process of flat-bottomed rivetless connection. However, this traditional flat-bottom rivetless connection method has the following disadvantages: the material of the traditional flat-bottom rivetless connection flows upward from the bottom of the punch, and the fricti...

AI Technical Summary

Problems solved by technology

However, this traditional flat-bottom rivetless connection method has the following disadvantages: the material of the traditional flat-bottom rivetless connection flows upward from the bottom of the punch, and the friction resistance of the punch to it is large, which is easy to cause damage or even cracks to the internal material; The flow of the traditional flat-bottom riveted connection is a one-way reverse extrusion method, the resistance is large during flow, the external load required for forming is large, and the forming is difficult; the connection strength is lower than that of punch riveting connection

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