Three cylinder bending machine is a type of machine used by enterprises. On the basis of the original two cylinders, an auxiliary cylinder has been added in the middle of the slider to better reduce the deformation of the slider caused by long-term use. Effectively improving the accuracy of machining workpieces, it is a new generation of updated equipment after the double cylinder bending machine. Especially on large bending machine processed products, its superior performance is better reflected.

Structural characteristics of three cylinder bending machine:

1. Adopting a fully welded steel structure with sufficient strength and rigidity;

2. Hydraulic transmission, the oil cylinders at both ends of the machine tool are placed on the slider, directly driving the sliding work;

3. The slider synchronization mechanism adopts torsion axis forced synchronization;

4. Adopting a mechanical block structure, stable and reliable;

5. Quick adjustment of slider travel, manual fine-tuning, counter display;

6. A wedge type deflection compensation mechanism is used to ensure high bending accuracy.

Correct selection of three cylinder bending machine:

If the wrong choice is made when selecting a bending machine, production costs will rise and the bending machine cannot be expected to recover costs. Therefore, there are several factors that need to be considered when making decisions.

Workpiece

An important consideration is the parts you want to produce, the key is to purchase a machine that can complete the machining task with a short worktable and small tonnage.

Carefully consider the material grade, as well as the thickness and length of the large processing. If most of the work is made of low carbon steel with a thickness of 16 gauge and a length of 10 feet (3.048 meters), then the free bending force does not need to exceed 50 tons. However, if engaged in large-scale bottom concave die forming, perhaps a 160 ton machine tool should be considered.

Assuming the thick material is 1/4 inch, a 10 foot free bending requires 200 tons, while a bottom die bending (corrected bending) requires at least 600 tons. If most of the workpieces are 5 feet or shorter, the tonnage is almost halved, greatly reducing the purchase cost. The length of the parts is crucial in determining the specifications of a new machine.

Scratching transformation

Under the same load, the deflection of the worktable and slider of a 10 foot machine is four times that of a 5-foot machine. This means that shorter machines require less gasket adjustment to produce qualified parts. Reducing gasket adjustments also shortens preparation time.

The material grade is also a key factor. Compared to low-carbon steel, stainless steel typically requires an increase of about 50% in load, while most grades of soft aluminum require a decrease of about 50%. You can always obtain the tonnage table of the bending machine from the manufacturer, which shows the estimated tonnage required per foot length for different thicknesses and materials.

Bending radius

When using free bending, the bending radius is 0.156 times the opening distance of the concave mold. During the free bending process, the opening distance of the concave mold should be 8 times the thickness of the metal material. For example, when forming 16 gauge low carbon steel with an opening distance of 1/2 inch (0.0127 meters), the bending radius of the part is approximately 0.078 inches. If the bending radius is almost as small as the material thickness, it is necessary to perform bottom concave die forming. However, the pressure required for forming with a bottom concave mold is about four times greater than that for free bending.

If the bending radius is smaller than the material thickness, a convex mold with a front rounded corner radius smaller than the material thickness must be used, and the embossing bending method should be sought. This requires 10 times the pressure of free bending.

In terms of free bending, the convex and concave molds should be processed at an angle of 85 ° or less (smaller points are better). When using this set of molds, pay attention to the gap between the convex and concave molds at the bottom of the stroke, as well as the excessive bending that is sufficient to compensate for rebound and keep the material at around 90 °.

Usually, the rebound angle generated by a free bending die on a new bending machine is ≤ 2 °, and the bending radius is equal to 0.156 times the opening distance of the die. For bottom concave mold bending, the mold angle is generally 86~90 °. At the bottom of the stroke, there should be a gap slightly larger than the material thickness between the convex and concave molds. The forming angle is improved because the tonnage of the bottom concave die bending is relatively large (about 4 times that of free bending), reducing the stress that usually causes rebound within the bending radius range.

Embossing bending is the same as bending with a bottom concave mold, except that the front end of the convex mold is machined to the required bending radius, and the clearance between the convex and concave molds at the bottom of the stroke is smaller than the material thickness. Due to the application of sufficient pressure (approximately 10 times that of free bending) forcing the front end of the punch to contact the material, rebound is basically avoided.

In order to select low tonnage specifications, plan for bending radii greater than the material thickness and use free bending methods as much as possible. When the bending radius is large, it often does not affect the quality of the finished product and its future use.

Instructions for using a three cylinder bending machine:

A brief introduction to processing Q235 sheet metal using a regular hydraulic bending machine:

1. Firstly, connect the power supply, turn on the key switch on the control panel, and then press the oil pump to start.

2. Travel adjustment: When using a bending machine, it is necessary to pay attention to adjusting the travel, and a test drive must be conducted before bending. When the upper mold of the bending machine descends to the bottom, there must be a gap of plate thickness. Otherwise, it will cause damage to the mold and machine. The adjustment of the itinerary also includes electric quick adjustment and manual fine adjustment.

3. When selecting a bending groove, it is generally necessary to choose a groove with a width 8 times the thickness of the board. If bending a 4mm sheet metal, a slot of about 32 should be selected.

4. Rear gear adjustment generally includes electric quick adjustment and manual fine adjustment, using the same method as a shearing machine.

5. Press the foot switch to start bending. Unlike the shearing machine, the bending machine can be released at any time. Release the foot switch to stop the bending machine, and then press it again to continue the downward movement.