Technical Principle and Procedure: The blank holder first moves downward to pre-press the riveting material to prevent the material from flowing into the die under the rivet force, and then the punch moves downward to push the rivet down to pierce the upper material. Under the joint action of die and punch, the rivet tail opens in the lower metal to form a bell shape for locking and connecting. When riveting two layers of the same metal material, the thicker layer is placed in the lower layer; when riveting two layers of different metal materials, the plastic material is placed in the lower layer; when riveting metal and non-metal materials, the metal material is placed in the lower layer.
We need to choose the right riveting process, which is all the process. There are three riveting processes for traffic signs: ordinary riveting, welding and self-piercing riveting.
The disadvantage of riveting process for ordinary rivets is that it needs piercing, drilling, fixing rivets, and riveting with pneumatic riveting gun. There are many processes, large workload, high comprehensive cost, noise pollution and other problems, which are not very ideal manufacturing process, but its advantages are less investment, can be put into production immediately, so it still has a certain market.
At present, due to the limitations of drilling, environmental protection, dust and high cost, welding is expected to be phased out step by step, so this process is that you already have an aluminium welding machine, and customers accept the welding mark plate manufacturing process can be used. Usually we do not recommend this process.
In this paper, a new self-piercing riveting method for outdoor traffic signs is provided by the self-piercing riveting machine of Wuhan Berrick Sign, which can solve the problems of poor connection performance between outdoor traffic sign boards and chutes in traditional ways and time-consuming and laborious installation on site. The concrete steps are as follows:
1. According to the performance requirements of outdoor traffic signs, the bottom plate and chute of the sign are selected, in which the thickness of the bottom plate of the sign 2 is 1.5 mm-2.0 mm and the chute thickness is 1.5 mm-2.0 mm.
2. The self-piercing riveting experiment of the selected bottom plate-chute material combination is carried out. The forming quality of the joint is observed by the section visual inspection method. The detection indexes include the height of the nail head, the opening of the nail foot and the residual bottom thickness. The rivet 4, the punch 5, the lower die 7 and the blank holder 8 of the suitable specification are selected to determine the self-piercing riveting parameters of the joint.
3. Self-piercing riveting machine is used to rivet the bottom plate of outdoor traffic signs and the joint of the sliding groove 3.
The rivet is a semi-hollow self-piercing rivet.
The inner diameter of the semi-hollow self-piercing rivet is 5.3 mm.
The riveting parameters are: pre-tightening force 50 bar, piercing force 180 bar-190 bar and shaping force 110 bar-140 bar.
The marking base plate 2 and the chute 3 are metal plates.
The self-piercing riveting machine is a big throat deep self-piercing riveting equipment of Wuhan Berrick.