The forging method of forming metal bars by upsetting a die (usually locally upsetting) at room temperature. The head used to make screws, bolts, rivets, etc. Cutting may be reduced or replaced.
Forging billet materials can be copper, aluminum, carbon steel, alloy steel, stainless steel and titanium alloy, etc., the utilization rate of materials can reach 80 ~ 90%. Cold heading is mostly carried out on special cold heading machine, which is convenient to realize continuous, multi-station and automatic production. In the cold heading machine, the process of cutting, upsetting, accumulating, forming, chamfering, twisting, reducing and trimming can be completed in sequence. High production efficiency, the maximum cold heading workpiece diameter is 48 mm. The bar is automatically fed to a certain degree by the feeding mechanism, and then cut off into blank by the cutting mechanism, and then sent by the clamp transfer mechanism to the pile shape and punching station for cold heading forming.
Two, this technology belongs to a kind of cold forming, that is, in the case of heating materials for punching shear, bending, deep drawing and other processing. Cold forming process includes cold heading, cold rolling, die forging and so on.
1, cold heading is mainly used for manufacturing bolts, nuts, nails, rivets and steel balls and other parts. To achieve continuous, multi-station, automatic production.
2. Forging billet materials can be copper, aluminum, carbon steel, alloy steel, stainless steel and titanium alloy, etc., with high material utilization rate.
3, according to the theory of metal plastic change, at room temperature to impose a certain pressure on the metal blank, make it in the mold cavity plastic change, according to the specified shape and size molding.
4, cold heading bolt, nut forming machinery has many models, many series of machines. The equipment performance is reliable, the efficiency is high, the product quality is stable.
5, good surface quality, high dimensional accuracy. Due to cold hardening in the upsetting process, the deformation is not large. Reduce cracking.
6, the cold heading process is applicable to large batch, all kinds of specifications of products, can reduce the cost.
7, multi-station cold pressing machine, compact structure, simple operation, precision processing. Widely used in automobile, bicycle chain standard parts and other industries, especially suitable for manufacturing all kinds of complex, special-shaped non-standard parts. Can directly use the disk element wire, multi - station molding.
8, multi-station cold heading machine adopts automatic circulation lubrication system to process products and materials, high utilization rate, high precision, good strength, improve power, increase enterprise efficiency.
2. What is a cold heading machine and cold heading process?
Cold heading machine is a special equipment mainly used for mass production of nuts, bolts and other fasteners. The world's first cold heading machine originated in Germany. The cold heading machine was developed to produce large numbers of bullet casings during World War II.
Cold heading process
(1) According to the theory of metal plastic change, a certain pressure is applied to the metal blank at room temperature to produce plastic change in the mold cavity, and the mold is formed according to the specified shape and size.
(2) Must choose high quality "plastic change" good metal materials, such as riveting steel, its chemical composition and mechanical properties have strict standards.
(3) There are many models and series of cold heading bolt and nut forming machinery. The equipment performance is reliable, the efficiency is high, the product quality is stable.
(4) the upsetting force of product forming is large, the power is configured in, and the equipment is invested in a time. Therefore, the production specification below M24 is the most economical.
(5) Good surface quality, high dimensional accuracy. Due to cold hardening during upsetting, the deformation should not be too large. Reduce cracking.
(6) Cold heading process is applicable to large batch and various specifications of products, so as to reduce the cost. The modern cold heading machine has been increased by the past simple two stations up to the current domestic new varieties of 5 die 6 die 6 die elongated cold heading machine.
3. How the automatic cold heading machine works
A forging process in which the top of a bar or wire is thickened at room temperature. Cold heading is mainly used to make bolts, nuts, nails, rivets and steel balls. Forging billet materials can be copper, aluminum, carbon steel, alloy steel, stainless steel and titanium alloy, etc., the utilization rate of materials can reach 80 ~ 90%. Cold heading is mostly carried out on special cold heading machine, which is convenient to realize continuous, multi-station and automatic production. In the cold heading machine, the process of cutting, upsetting, accumulating, forming, chamfering, twisting, reducing and trimming can be completed in sequence. The bar is automatically sent to a certain length by the feeding mechanism, the cutting mechanism will cut it into blank, and then the clamp transfer mechanism is sent to the pile shape and punching station in turn for forming.
4. Operating procedures of cold heading machine
First, do it carefully before work
1, check the knife plate, cutting tool rod, punch, die should be intact without cracking, correct installation, fastening firm.
2, after adjusting the cutting mechanism, must check the gap between the concave die clip, it is strictly prohibited to start the equipment without inspection.
3. In the case that the cutting tool rod has been folded, the roller in the CAM groove must be taken out before inching the equipment.
Second, work conscientiously
1. When starting the equipment, the main motor can be started to drive the flywheel to rotate only when the feeding device is disconnected. Only wait until the flywheel is at full speed before turning on the feed device. When stopping the equipment, the feeding device should be disconnected first and then the main motor should be stopped.
2, do not stop the slider in the "dead point" position, such as the slider stopped in the "dead point", only with manual disc flywheel method to correct, do not start the equipment.
3. In the case that the cutting tool rod has been folded, the roller in the CAM groove must be taken out before inching the equipment.
4, often pay attention to the work of the tray rack, found chaos should immediately stop. Plate material processing to nearly finished, should be the end of the material from the plate frame out.
5. How to select bolts and nuts?
1. The plasticity index required by the bolt (stud), the higher the performance grade, only the higher level of material can be achieved. Low grade materials only by reducing the tempering temperature to reach the strength requirements, but can not meet the plasticity, toughness requirements. In fastener testing, brittle fracture is disqualified (even if the tensile strength meets the requirements). The maximum tensile strength of structural steel bolts is also specified to ensure the plastic toughness of the bolts.
2. The mechanical properties of the nut mainly depends on the hardness of the nut and the height of the nut, the wall thickness of the nut. Therefore, the requirements for materials are not high. Of course, the nut has the toughness requirements, should also use a higher level of materials, such as chemical fastener nuts have the toughness requirements on the provision of higher materials.