Working principle and characteristics of cold heading machine
Source：http://www.xuehu9.com Author：冷鐓機 Time：2014/10/14 Click：
Working principle of cold heading machine
The forging method of thickening the top of bar or wire at room temperature. Cold heading is mainly used for manufacturing parts such as bolts, nuts, nails, rivets, and steel balls. The forging billet material can be copper, aluminum, carbon steel, alloy steel, stainless steel, titanium alloy, etc., and the material utilization rate can reach 80-90%. Cold heading is often carried out on specialized cold heading machines, which facilitates continuous, multi station, and automated production. The cold heading machine can sequentially complete processes such as cutting, heading, accumulation, forming, chamfering, wire rolling, diameter reduction, and edge cutting. High production efficiency, reaching over 300 pieces per minute, with a maximum diameter of 48 millimeters for cold heading workpieces. The schematic diagram of the cold heading bolt process in Figure 1 is a typical process of cold heading bolts. Figure 2: The multi station nut automatic cold heading machine is a multi station nut automatic cold heading machine. The bar material is automatically fed into a certain length by the feeding mechanism, cut into blanks by the cutting mechanism, and then sequentially sent to the accumulation and punching stations for forming by the clamp conveying mechanism.
In the cold heading method, the cold heading machine can be divided into two types: mechanical transmission and hydraulic transmission according to the different ways of power transmission. There are two types of mechanical transmission: manual and electric. Electric and manual cold heading machines are suitable for cold heading low-carbon steel wires with a diameter of 4-5mm. Hydraulic transmission can be divided into two types based on its performance: hydraulic steel wire cold heading machine and hydraulic steel bar cold heading machine.
Construction and working principle of manual cold heading machine
Manual cold heading machine is a type of steel bar heading machine and structure that uses human power as the driving force to press the steel bar head into the desired shape.
The working principle of a manual cold heading machine is to pull handle 6 to move the upper and lower clamping blocks of fixture 1 backwards. Due to the contact between the clamping block and the conical sleeve, the upper and lower blocks of fixture 1 are separated under the action of the conical surface. At this time, wire 7 is sent to the fixture mouth and pushed to the top of upsetting die 2. Release handle 6, and under the action of spring 3, wire 7 is automatically clamped. At this point, turn the eccentric wrench 5 to drive the eccentric 4 to rotate, forcing the upsetting die 2 to move forward and complete the wire end upsetting. Return the eccentric block 4 to its original position, use the pressure spring 3 to reset the upsetting die 2, pull the handle 6 to separate the fixture 1, and remove the upsetting steel wire. The manual cold heading machine has a simple structure, is easy to use, and is not limited by power supply, but is only suitable for cold heading small diameter (φ 4-5mm) low-carbon steel wire.
Key points for using manual cold heading machine
(1) The diameter of steel bars or wires should meet the requirements of the cold heading machine, and steel bars (wires) that are too coarse or too fine cannot be cold headed;
(2) Within the allowable range of the cold heading diameter of the punching machine, the position of the fixture (screw in or screw out) can be adjusted according to the required anchor head size to obtain a suitable amount of steel bar (wire) extension allowance;
(3) Within the 120-130mm area of the cold heading part of the steel bar (wire), rust removal and straightening are required;
(4) The end of the steel bar should be ground flat to ensure the accurate shape of the cold heading anchor head;
(5) After the steel bar is upset, it must undergo a tensile test to verify whether the strength of the anchoring head is qualified.
The above requirements also apply to electric and hydraulic cold heading machines. The working principle of electric and hydraulic cold heading machines is the same except for the difference in power compared to manual cold heading machines.
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