Pull Bend Manufacturer: Classification and Parameters of Pull Bend

Stash bending is a workpiece stamping process that bends sheet metal, pipe, and steel into a specific curvature, shape, and size. Bending forming is widely used in the manufacture of high-pressure vessels, boiler drums, boiler tubes, hull steel plates and bone ribs, various utensils, instrument components, box inlays, etc. Below, the bending manufacturers share why the bending process is widely used in containers, boilers and cabinets.

When the material is bent, the stress state of each part in the deformation area is different. The non-deformed part of the middle of the cross section is called the neutral layer. The metal outside the neutral layer produces tensile deformation under the action of tensile stress. The compressive stress action of the metal inside the neutral layer leads to compressive deformation. The bending manufacturer believes that because the stress and strain directions of the metals on both sides of the neutral layer are opposite, the elastic deformation of the metals on both sides of the neutral layer will return to the opposite direction when the load is unloaded, resulting in different degrees of elastic deformation. The tensile bending deformation is limited to the local area of the material, but the elastic compound effect will affect the accuracy of the bent part. There are many factors affecting the bullet loading, which are difficult to control, and the precision of the ball caused by the bullet loading has always been the key to the production of the die.

The manufacturer introduces the classification of the pull bending:

According to the process characteristics, pulling can be divided into top, bend, roll and pull.

Pull bending is a commonly used bending method. Most of the equipment used is an ordinary mechanical press or hydraulic press, as well as a dedicated bending press. The commonly used roll bending equipment is a bending machine. The three-roll roller is the reason for the three o'clock decision circle, and the continuous bending of the blank. The three-roller roller has two drive rollers (fixed) and one pressure roller (adjustable). By adjusting the upper and lower positions of the pressure roller, the relative distance to the drive roller can be changed. When bending, the plate is placed between the transmission roller and the pressure roller, and the transmission roller rotates in the opposite direction to make the plate move back and forth. Gradually lowering the pressure roller can bend the flat plate to the cylindrical surface of the required curvature, the conical surface and the hyperbolic surface with the smaller curvature. By pressing one end of the roller, the workpiece can be easily removed. In addition, the bending manufacturer believes that there are four-roll and multi-roll bending machines. The four-roller plate bending machine is used to roll thick plate cylinders, and the multi-roller plate bending machine with more than four rollers uses multiple pairs of rollers to gradually bend the plate to a complex contour surface.

In the case of high precision, curved parts with large length and radius of curvature and small side size can be bent on a special bending machine. When bending, the overall thickness of the plate is affected by the tensile stress, and only tensile deformation occurs. After unloading, the deformation caused by the elastic loading is small, and the accuracy is easy to guarantee.

Pull bending manufacturers share process parameters:

The selection of appropriate processing parameters is the key to the bending process. In addition to the relatively small deformation factors such as molds, the process parameters that affect the quality of bending and forming also include the tensile force and deformation during the bending process. There are two main factors that limit bending in production. One is bending rupture, and the other is that the cross-sectional dimension deformation is too large. These two aspects are the first to be considered when determining the parameters of the pulling process. In addition, the smaller elastic recovery amount is also one of the important basis for selecting the tensile bending process parameters. In the finishing bending process, if the processing parameters are not selected properly, unstable folds may appear. The stretch bending manufacturer believes that this is an important factor to be considered. Extruded steel is considered to be a special sheet metal material whose dimension is much smaller than the other two directions. Therefore, in the forming process, it can usually be considered to be completed under plane stress. However, the big difference between profile tension and sheet forming is that sheets can usually be considered isotropic, but the anisotropic characteristics of extruded profiles are more obvious.

The members where the pivot tension and bending moment act together become tensile bending members, including eccentric tensile members and lever members with lateral loads. For the bending members in the steel structure, the bending moment is not large, and the cross-sectional shape is the same as that of the ordinary pivot lever under the condition of mainly bearing the pivot tension. Bending is the result of a combination of tension and bending moments, and the presence of plastic hinges in the cross-section is considered to be a limitation of allowable capacity. However, the stretch bending manufacturer believes that for the lattice or cold-formed thin-walled steel components, if the cross-sectional edge is shown as plastic, the strength limit is basically reached. In general, bending members are less likely to lose overall stability and partial stability.