CN111889866A

CN111889866A - Friction hot riveting threaded nail and welding process

Info

Publication number: CN111889866A
Application number: CN202010564278.7A
Authority: CN
Inventors: 邢晓芳; 韩佩; 周勇; 路浩
Original assignee: Xian Shiyou University
Current assignee: Xian Shiyou University
Priority date: 2020-06-19
Filing date: 2020-06-19
Publication date: 2020-11-06

Abstract

A friction hot riveting screw thread nail and a welding process comprise a nut, wherein an annular convex point is arranged on the lower surface of the nut, the tip end of the convex point is conical and is provided with a thread, and the nut and the annular convex point are manufactured integrally. The electrode on the projection welding machine is provided with a nut clamp, a nut of the friction hot riveting threaded nail is clamped on the nut clamp and is driven to rotate by the upper electrode, the annular convex point contacts the plate to be welded, after the nut is electrified, the nut convex point is screwed into the plate and is melted under the action of friction heat and resistance heat, so that the simultaneous action of the friction heat and the resistance heat is realized, the convex point and the plate are melted, and the welding is realized. The technology greatly improves the fusion depth of the welding core, improves the forming defects of insufficient solder, splashing and the like, realizes high-efficiency nut projection welding, and obviously improves the welding efficiency.

Description

Friction hot riveting threaded nail and welding process

Technical Field

The invention belongs to the technical field of resistance welding and friction welding, and particularly relates to a friction hot riveting threaded nail and a welding process.

Background

Nut projection welding is a key technology in the white automobile body manufacturing process, but because the nut projection welding time is very short, the nucleation size is narrow, the conditions of insufficient welding, splashing and inconsistent multi-projection welding are very easy to occur, the assembly quality of the whole workpiece or even the whole automobile is directly affected in severe cases, and sometimes, workers are required to perform secondary repair welding to affect the assembly process.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a friction hot riveting threaded nail and a welding process, which greatly improve the fusion depth of a welding core, improve the forming defects of insufficient solder, splash and the like, realize high-efficiency nut projection welding and obviously improve the welding efficiency.

In order to achieve the purpose, the invention adopts the technical scheme that:

the friction hot riveting threaded nail comprises a nut and is characterized in that an annular convex point is arranged on the lower surface of the nut, the tip end of the convex point is conical and is provided with a thread, and the nut and the annular convex point are integrally manufactured.

The welding process of the friction hot riveting threaded nail is characterized by comprising the following steps of: the electrode on the projection welding machine is provided with a nut clamp, a nut of the friction hot riveting threaded nail is clamped on the nut clamp and is driven to rotate by the upper electrode, the annular convex point contacts the plate to be welded, after the nut is electrified, the nut convex point is screwed into the plate and is melted under the action of friction heat and resistance heat, so that the simultaneous action of the friction heat and the resistance heat is realized, the convex point and the plate are melted, and the welding is realized.

The invention has the beneficial effects that:

1) under the condition of achieving the same fusion depth, the method of the invention has the advantages of smaller current, shorter welding time, higher efficiency, obvious energy saving and improvement of economic benefits of enterprises.

2) Because the salient point screw thread exists and the nut is driven to rotate, the electrode pressure can be reduced, and the screw thread deformation probability is reduced.

3) Because the nut is driven by the upper electrode to rotate, the annular salient points are stressed uniformly, the uniformity of a welding core can be improved, and the forming defects such as splashing, insufficient welding and the like are reduced.

4) Because the nut salient point is provided with the thread, the connection of the welding joint is firmer.

Drawings

Fig. 1 is a schematic structural view of the present invention. Fig. 2 is a top view of the bottom end of the nut, in which the annular strip is an annular bump.

Fig. 3 is a schematic view of a welding process.

Fig. 4 is a pre-weld joint shape.

Fig. 5 shows the shape of the welded joint, and the welded joint can be formed well by the resistance heat and the frictional heat.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

As shown in fig. 1 and 2, the friction hot riveting screw comprises a nut and is characterized in that an annular convex point is arranged on the lower surface of the nut, the tip of the convex point is conical and is provided with a thread, and the nut and the annular convex point are manufactured integrally.

As shown in fig. 3, 4 and 5, the welding process of the friction hot riveting screw nail is characterized by comprising the following steps: the electrode on the projection welding machine is provided with a nut clamp, a nut of the friction hot riveting threaded nail is clamped on the nut clamp and is driven to rotate by the upper electrode, the annular convex point contacts the plate to be welded, after the nut is electrified, the nut convex point is screwed into the plate and is melted under the action of friction heat and resistance heat, so that the simultaneous action of the friction heat and the resistance heat is realized, the convex point and the plate are melted, and the welding is realized.

Before welding, as shown in fig. 4, the tip of the convex point of the nut is conical and is provided with threads to be tightly contacted with the plate. After welding is started, the tip of the nut salient point is pressed into the plate under the action of pressure, the nut is driven to rotate by the upper electrode, and the nut salient point is further screwed into the plate under the action of rotation and threads. The conical shape of the convex points and the existence of the threads both obviously accelerate the process of pressing the convex points into the plate, and improve the welding efficiency. Meanwhile, under the action of resistance heat and friction heat, the salient points and the plate are partially melted, the melted parts are combined together to form welding points, the welding of the nut and the plate is completed, and the nut and the plate are welded more firmly due to the existence of the threads.

Claims

1. The friction hot riveting threaded nail comprises a nut and is characterized in that an annular convex point is arranged on the lower surface of the nut, the tip end of the convex point is conical and is provided with a thread, and the nut and the annular convex point are integrally manufactured.

2. The welding process of the friction hot riveting threaded nail is characterized by comprising the following steps of: the electrode on the projection welding machine is provided with a nut clamp, a nut of the friction hot riveting threaded nail is clamped on the nut clamp and is driven to rotate by the upper electrode, the annular convex point contacts the plate to be welded, after the nut is electrified, the nut convex point is screwed into the plate and is melted under the action of friction heat and resistance heat, so that the simultaneous action of the friction heat and the resistance heat is realized, the convex point and the plate are melted, and the welding is realized.