In our sheet metal processing production process, what exactly is sheet metal processing bending technology?

With the wide range of sheet metal processing technology and application fields, the rapid mass production of flexible sheet metal and pipe fittings processing machines has become one of the most popular in this field. In addition to the equipment for bending, punching and composite punching laser processing, it can provide high-precision precision parts customization with systems for laser cutting and laser welding applications. As a sheet metal processing manufacturer with more than ten years of production experience, what are the sheet metal forming technologies in our processing and production solutions?

Sheet metal forming processes are processes in which force is applied to a sheet of metal to change its geometry rather than remove any material. The applied force pushes the metal beyond its withstand strength, causing the material to plastically deform, but not fail. By doing so, the sheet can be bent or stretched into a variety of complex shapes.

In the process of sheet metal processing and production, many people mentioned a bending technology problem of sheet metal processing, so what exactly is sheet metal processing bending technology?

Bending is a metal forming process in which force is applied to a sheet of metal causing it to bend at an angle and form the desired shape. Bending operations result in deformation along one axis, but a sequence of several different operations can be performed to create complex parts. Curved parts can be very small, such as brackets, or as long as 20 feet, such as large enclosures or chassis. Bending can be characterized by several different parameters, as shown in the figure below.

Bend Line - A straight line on the sheet surface on both sides of the bend that defines the end of the horizontal flange and the start of the bend.

Outer Mold Line - Whether the line where the outer surfaces of the two flanges meet is continued. This line defines the edge of the die for the bent sheet metal.

Flange Length - The length of either of the two flanges, extending from the edge of the paper to the bend line.

Die Line Distance - The distance from either end of the sheet to the outer die line.

Setback - The distance from the bend line to the outer mold line. Also equal to the difference between the die line distance and the flange length.

Bend Axis - The line that defines the bend center of the sheet metal.

Bend Length - Bend length measured along the bend axis.

Bend Radius - The distance between the bend axis and the inner surface of the material, between the bend lines. Sometimes specified as the inner bend radius. The outer bend radius is equal to the inner bend radius plus the plate thickness.

Bend Angle - The bend angle, measured between the bend flange and its original position, or as the angle between a vertical line drawn from the bend line.

Bevel - the complementary angle to the bend angle.

The action of bending causes tension and compression in the metal sheet. The outer portion of the sheet will experience tension and stretch to a greater length, while the inner portion will undergo compression and shortening. The neutral axis is the boundary line inside the metal plate along which there is no tension or compression. As a result, the length of this axis remains the same. The length variation of the outer and inner surfaces can be related to the original plane length by two parameters (bend allowance and bend deduction), which are defined below.

Neutral Axis - The location in the sheet that is neither stretched nor compressed, thus maintaining a constant length.

K-Factor - The location of the neutral axis in a material, calculated as the ratio of the distance from the neutral axis (measured from the interior curved surface) to the thickness of the material. The K-factor depends on several factors (material, bending operation, bending angle, etc.) and is usually greater than 0.25, but cannot exceed 0.50.

Bend Allowance - The length of the neutral axis between bend lines, or in other words, the arc length of the bend. The bending allowance added to the flange length is equal to the total flat length.

Bend - Also known as Bend Compensation, is the amount a piece of material is stretched through bending. This value is equal to the difference between the die line length and the total flat length.

When bending a sheet of metal, residual stresses in the material will cause the sheet to spring back slightly after the bending operation. Due to this elastic recovery, the sheet must be overbent by the exact amount to achieve the desired bend radius and bend angle. The final bend radius will be larger than the originally formed bend radius, and the final bend angle will be smaller. The ratio of the initial bend angle to the final bend angle is defined as the springback factor. The amount of springback depends on several factors, including the material, the bending operation, and the initial bend angle and bend radius.