Key points to note when installing anti-wrinkle molds Hehe Machinery

With the rapid development of my country's economy, pipe bending machines are increasingly used in the construction of power generation pipelines, urban water supply, and gas pipelines. The development of large-diameter hot pipe bending machines can not only save a large amount of foreign exchange, but also improve the design and manufacturing level of large-scale equipment in my country. The main part of the pipe bending machine is equipped with important components such as pipe bending molds, turntables, and pipe bending machine spindles. The clamping of the pipe is achieved by clamping cylinders and clamping screws. The pipe bending parts are fixed by the pipe bending spindle, which rotates with the rotation of the pipe bending mold of the main part, and the pipe bending is achieved by cooperating with the pipe bending mold of the main part of the pipe bending machine. When bending pipes with larger diameters, smaller bending radius, and thin pipe walls, wrinkle-proof molds and ball core rods should be used.

When the pipe is bent, the material inside its center line is compressed. When it is bent to a certain angle, the material will be pushed back and exceed the tangent point due to the large compression force of the material. If the pipe wall in this area is not supported by the bending die, wrinkles will form. Even if it is flattened between the core rod and the bending die in the future, the wrinkles cannot be eliminated. And when the bending is finished, a large wrinkle will be formed on the tube.

Using the anti-wrinkle die can increase the support of this area, so that the tube wall will be evenly thickened after compression without wrinkles. However, due to improper adjustment, the anti-wrinkle die cannot eliminate wrinkles after wrinkles have been generated.

The shape of the anti-wrinkle die is very important. The groove through which the tube slides should be slightly larger than the outer diameter of the tube, and its value can be 10% of the wall thickness. It should also be carefully polished to prevent scratches on the tube.

The front end of the anti-wrinkle die should be made very thin, extending to the tangent point of the bending die, supported by the bending die, and fixed to form a closed cavity. In order to reduce the resistance during bending, the anti-wrinkle die should have a slight taper when installed. The pressure of the compression die should be adjusted appropriately. When installing and adjusting the anti-wrinkle die, it is best to use an "adjustment mandrel" and do it with the clamping die clamped.

During the bending process, a proper layer of oil should be applied to the anti-wrinkle die. However, too much or too thick oil will also cause wrinkles in this area. When using anti-wrinkle molds, ball core rods are often used at the same time. Anti-wrinkle molds are used to prevent wrinkles on the tube when bending; while the ball core rod can keep the tube from collapsing after leaving the core rod support point.

When bending thin-walled, large-diameter, and small-bending-radius tubes, in order to avoid wrinkles, the following points should be noted:

① Reduce the resistance between the core rod and the inner wall of the tube during bending. Before the tube is bent, the inner cavity must be wet-sandblasted.

② The machine tool and spindle should have sufficient rigidity.

③ The core rod should have sufficient rigidity to eliminate the trembling and stretching caused by the rod as much as possible.

④ The radial clearance between the core rod and the inner diameter of the tube should not be greater than 10% of the wall thickness.

⑤ The clamping die, pressing die, core rod, and anti-wrinkle mold should be properly adjusted, especially the pressing die pressure should be carefully selected and adjusted.

When bending large-diameter tubes, the clamping die clamping is also a prominent problem. This requires that the straight section between the two bends of the pipe is longer and the clamp is wider to increase the clamping force and ensure smooth bending. If the clamp is too narrow and there is not enough clamping force when bending, the pipe will slip and not move forward, making the bending impossible.

⑥ Choose an appropriate amount of lubricating oil.

⑦ The supply status of the material is also very important. For stainless steel pipes, the hardness is HB=180~220, and HB=180 is the most suitable.

Zhangjiagang Hehe Machinery Co., Ltd. is a Taiwanese investment enterprise. It specializes in the research and development and manufacturing of metal circular saw machines, CNC pipe bending machines, pipe end forming machines and other pipe machinery and equipment. Our company adheres to Taiwan's advanced technology to develop and manufacture metal circular saw machines, CNC pipe bending machines, pipe end forming machines and other pipe processing machinery and equipment in response to the needs of furniture, sports equipment, car driving, auto parts, air conditioning pipes, decorative materials and other industries. The company can also design and manufacture special specifications of models and various non-standard machinery and equipment according to customer needs.