Sheet metal processing technology – riveting
Riveting is the joining of two objects together to form a non-removable connection. Mindray’s commonly used connection forms: pressure riveting, pull riveting, and rising riveting.
1. Pressure riveting process requirements
(1) When the stainless steel plate is pressed against the stainless steel (CLS) nut, due to the high carbon content (hardness) of the stainless steel, in order to reduce the risk of the nut falling off after pressing, it is necessary to weld the nut close to the plate (spot welding points) reinforcement.
(2) It is not recommended to press the hole and press the stud before electroplating, in order to prevent the electroplating solution from completely flowing out and corroding the thread.
(3) When riveting, the die should be used to press in place at one time, and the hexagonal head of the stud should be completely embedded in the plate and flush with the surface of the part to ensure the flatness of the plate and the verticality of the column and the plate.
(4) When the stud length L>30mm, the stud welding (circumferential spot welding) should be reinforced to prevent skewing according to structural analysis and process requirements.
(5) When the stainless steel plate presses the stainless steel stud, the tolerance of the outer diameter (C) of the stud and the size of the opening of the plate must be guaranteed to be 0.05mm.
(6) When the length of the riveting locating pin is L>20mm, according to the structural analysis and process requirements, the locating pin needs to be reinforced by welding (spot welding at the round head) to prevent skew.
1.1 Pressure riveting nut
Nuts can be crimped on sheet metal for screw mounting.
1.2 crimping screws
Screws can be crimped on sheet metal and can be used for device mounting nuts.
1.3 Crimp stud
Crimp studs with internal threads on sheet metal for mounting devices with certain height requirements.
1.4 Captive-screw
The screws fixed to the sheet metal can prevent the inconvenience caused by accidentally losing the screws. In addition, if the tightening requirements are not high, hand-tightened screws can also be selected, eliminating the need for a screwdriver.
2. Riveting process requirements
(1) When the riveting is raised, the die should be used to raise it in place at one time. The boss part of the screw (size A) should be completely embedded in the bottom hole of the plate, and should be turned circularly and flattened according to the size and angle of the countersunk hole to ensure the convexity after raising ( A size) is not higher than the plane of the plate to ensure the flatness of the plate and the verticality of the rivet and the plate.
(2) Pay attention to the selection of molds. The taper of the mold on the riveting and loosening screws must be consistent with the angle of the countersunk hole of the plate.
1.3 Pull riveting process requirements
(1) The riveted parts should reserve the space for the riveting gun and the rivets.
(2) The dimensional tolerance of riveting is not too strict
(3) The material is too thin, it is difficult to riveting, and it is easy to cause gaps in the lax fit, so it is not recommended to riveting materials with a thickness of less than or equal to 0.5.
(4) The self-riveting structure is recommended when the thin plate is not under too much stress.