No.699, Chuangye Road, Tongyuan Industrial Park, Haiyan, Zhejiang Province, China
At present, the only connection method used to fix the threaded connection nut on the sheet is riveting. There are two methods and tooling for riveting. One is riveting, which is mainly used for small batches of various types and repair-based sheet metal The other is to use sheet metal stamping die riveting, which is mainly used for the riveting of a single type of sheet metal parts in large quantities. Both of these two riveting methods have fatal defects - low production efficiency, high labor intensity and poor stability of riveting quality.
1. Rivet gun riveting
The riveting process of the rivet gun is as follows: take the part, pierce the nut, screw the rivet head into the nut, pull the rivet, and unscrew the nut with the rivet head. The defects of the rivet gun riveting method: the process is cumbersome, the power of manual nut insertion is low, the production efficiency is low, the technical requirements for employees are high, the service life of the rivet gun is short, and the service life of the rivet gun head is short.
2. Die riveting
Mold riveting process: take the part - pierce the nut - position on the mold - press riveting - product. Defects of the die riveting method: the process is cumbersome, the power of manual nut insertion is low, the production power is low, the fixed stroke riveting method has poor compatibility with the nut length deviation, and the riveting quality is unstable.
3. Automatic plug-in device
Automatic plug-in equipment has been widely used in the sheet metal industry, and the technology has been appropriately mature, but because the riveting nut selected by the automatic plug-in equipment is a pressure riveting nut, there is no precedent for selecting a rivet nut. Compared with pull riveting, pressure riveting still has the following defects:
(1) For the same standard rivet nut, the cost of the pressure rivet nut is higher than that of the rivet nut.
(2) Press riveting has strict requirements on the thickness of the sheet, so it is not suitable for parts that require the use of thin materials. If the thickness of the sheet is increased in order to get used to riveting, the production cost will be greatly increased. At the same time, the structural parameters of the rivet nuts selected for different plate thicknesses are also inconsistent. If the rivet nuts are selected for production, the types and standards of nuts will be added, which will eventually lead to increased production management and quality management costs.
Most of the rivet nuts used in the sheet metal industry are hexagonal rivet nuts. At present, the general automatic plug-in equipment cannot be used for this type of rivet nut. The main reason is that the automatic plug-in equipment cannot realize the directional transportation of hexagonal rivet nuts. If the hexagonal rivet nut is replaced with a cylindrical rivet nut, the problem of directional transportation of the rivet nut can be solved. However, after the cylindrical rivet nut is riveted, there will be a quality risk of rotation when the screw is screwed.