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Sheet metal bending processing content and 14 common problems and solutions, good article!
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First, the bending processing content

1, L fold

According to the angle, it is divided into 90 folds and non-90 folds.

General processing (L>V/2) and special processing (L)

1. The mold is selected according to the material, the thickness of the plate and the forming angle.

2, the principle of relying on

1) Based on the principle of two rear gauges, and positioned by the shape of the workpiece.

2) When a rear gauge is in position, pay attention to the skew and require the workpiece to be on the same centerline.

3) When the small bend is bent, the reverse position processing is better.

4) It is better to lower the middle of the rule. (The rule is not easy to lift after the position is fixed)

5) It is better to rely on the side to the nearest rule.

6) It is better to use the long side to stay.

7) Aided by the fixture (the oblique side is irregularly positioned)

3, matters needing attention

1. Pay attention to the positioning method during processing and the movement method after the regularization in various machining methods. 2. When the mold is being assembled, it will be bent, and the post-rule will be pulled back to prevent the workpiece from being deformed during bending.

3. When the internal part of the large workpiece is bent, the shape of the workpiece is large, and the bending area is small, so that the tool and the bending area are difficult to overlap, which makes the positioning of the workpiece difficult or the bending of the workpiece is damaged. In order to avoid the above situation, an positioning point can be added in the longitudinal direction of the machining, so that the positioning is processed in two directions, which makes the machining positioning convenient, improves the processing safety, avoids the damage of the workpiece, and improves the production efficiency.

2, N fold

N folds must be processed differently depending on the shape. When bending, the size of the material is larger than 4MM, and the size of the X size is limited by the shape of the mold. If the material size is less than 4MM, it is processed by a special method.

1. Select the mold according to the material thickness, size, material and bending angle.

2, the principle of relying on

1) Ensure that the workpiece does not interfere with the tool

2) Ensure that the abutment angle is slightly less than 90 degrees.

3) It is best to use two post-rules to be in place, except in special circumstances.

3, matters needing attention

1) After bending the L-fold, the angle should be guaranteed at 90 degrees or slightly less than 90 degrees to facilitate the machining.

2) When the second folding process is performed, it is required that the position of the abutment is centered on the machined surface.

3, Z fold

Also known as the step difference, that is, one is positive and the other is bent. According to the angle, the difference between the oblique section and the straight edge is divided. The minimum size of the bending process is limited by the machining mold, and the maximum machining size is determined by the shape of the processing machine. Under normal circumstances, when the Z-fold material size is less than 3.5T, the step-die machining is used. When it is greater than 3.5T, the normal processing method is adopted.

1. Principle of abutment

1) Easy to position and good stability.

2) Generally, the position is the same as the L-fold.

3) The secondary position is required to level the workpiece and the lower mold.

2, matters needing attention

1) The processing angle of the L-fold must be in place, generally required to be 89.5---90 degrees.

2) When the post-rule is to be pulled back, pay attention to the deformation of the workpiece.

3) The order of processing must be correct.

4) For special processing, it can be processed as follows: ------- center line separation method (eccentric machining) ------- small V processing (need to increase the bending coefficient) ----- -- Easy mold forming ------- grinding the lower mold

4, reverse folding flattening

The re-folding flattening is also called pressing the dead side. The processing steps for the dead side are:

1. Bend the depth to about 35 degrees.

2. Flatten with a flattening die until it is flat.

1, mode selection

Select the V-groove width of the deep-die under the 5--6 times material thickness and select the upper die according to the specific conditions of the processed dead edge.

2, matters needing attention

The dead side should pay attention to the parallelism of the two sides. When the dead edge is processed for a long time, the flattened edge can be folded first and then flattened. For shorter dead edges, bedding processing is available.

5, press hardware

The use of folding bed to press the hardware, generally use the die, jig and other auxiliary mold processing. Under normal circumstances: pressure nuts, pressure studs, pressure screws and other hardware.

 Processing considerations

1. When the shape of the workpiece needs to be avoided, it should be avoided.

2. After the machining, the torque should be tested, whether the thrust reaches the standard and whether the hardware and the workpiece are flat and close. 3, after bending and pressing, when pressing next to the machine, pay attention to the avoidance of machining and the parallelism of the mold.

4. If it is bulging, it should also be noted that there should be no cracks in the bulging edge, and the bulging edge cannot be higher than the surface of the workpiece.

6, easy to mold

Generally, the processing content of easy mold forming includes: small step difference, hook, draw bridge, pumping, compression spring and some irregular shapes.

The design principle of easy mode refers to "LASER cutting easy mode design principle". Easy mode is generally defined by post or self-positioning.

The most important thing is that the function and assembly requirements are not affected and the appearance is normal.

Second, the common problems of folding bed processing and its solutions

1. Producing a slippery image during processing

Cause Analysis: 

1. Generally, the V-groove width of (4-6) T is selected when bending the mold. When the size of the bend is smaller than the width of the selected V slot

In half, there is a slippage phenomenon.

2, the selected V slot is too large

3, process processing

Solution; 

1. Centerline deviation method (eccentric machining). If the size of the material in the bend is less than (4-6) T/2, how much does it cost?

2, litter processing.

3. Bend with a small V-slot and pressurize with a large V-slot.

4. Use a smaller V-groove.

2, the internal bending width is narrower than the standard mold width

Cause Analysis: 

Since the standard width of the lower die of the folding bed is at least 10 mm, the bending processing part is less than 10 mm. If it is a 90 degree bend, its length should not be less than √2 (L+V/2)+T. For such bending, it is necessary to fix the mold on the mold base (that is, the degree of freedom in the upward direction is not limited) to avoid the displacement of the mold and cause the workpiece to be scrapped or cause a safety accident.

Solution: 

1, increase the size (to be with the customer), that is, increase the width of the internal fold.

2, easy to mold processing

3, grinding tools (this will lead to increased processing costs)

3. The hole is too close to the bend line, and the bend will pull the hole and turn the material.

Cause Analysis: 

Assume that the distance of the hole from the bend line is L, when L < (4---6) t>

1. Increase the size and repair the hem after forming.

2. Expand the hole to the bend line (must have no effect on the appearance, function, and the customer agrees).

3, secant processing or crimping

4, mold eccentric processing

5, modify the hole size

4. The distance between the extracted edge and the bending line is small, and the deformation at the drawing is performed after bending.

Solution: 

1, secant processing or pressure line processing.

2. Modify the shape of the drawing.

3, using special mold processing

4, mold eccentric processing

5, long dead side flattened after lifting

Cause Analysis: 

Since the dead side is long, it does not stick tightly during flattening, which causes the ends to be flattened and then lifted up. This happens, and has a great relationship with the flattening position, so pay attention to the flattening position when flattening.

1. Fold a corner (see the schematic) before folding the edge, and then flatten it.

2, divided into multiple steps:

------ Press the end first, so that the dead side bends downward. ------ flatten the roots.

Note: The flattening effect is related to the operator's work skills, so please pay attention to the actual situation when flattening.

6, large height draw bridge is easy to break

Cause Analysis: 

1. Since the height of the draw bridge is too high, the material is severely stretched and causes breakage.

2, easy to mold corners are not repaired or repaired enough.

3. The toughness of the material is too poor or the bridge body is too narrow.

Solution: 

1. Lengthen the process hole on one side of the fracture.

2. Increase the width of the draw bridge.

3. Grind the easy-to-model R angle and increase the arc transition.

4. Add lubricating oil to the drawbridge. (Therefore, the method will make the surface of the workpiece dirty, so it cannot be used for AL parts, etc.)

7, when easy to mold processing, the processing size will run

Cause Analysis: 

Since the workpiece is subjected to a forward pressing force during the machining, the workpiece is displaced forward, resulting in an increase in the small small angle L of the front portion. Solution: 

1. Grind out the shadows in the figure. Generally, it is much worse if you make a difference.

2. The easy-mode self-positioning part will be completely worn away, and the specified position will be changed after use.

8. The total size of the material to be cut (referring to the expansion) is too small or too large, which does not match the round surface.

Cause Analysis: 

1. The project is unfolding.

2. The size of the blank is incorrect.

Solution: 

The deviation assigned to each fold is calculated based on the total amount of deviation in the deviation direction and the number of bending knives. If the calculated distribution tolerance is within the tolerance, the workpiece is acceptable. ----- If the size is too large, you can use a small V-groove. ----- If the size is too small, you can use a large V-groove.

9. After the hole is twisted, the split or the twist is not tight, and the deformation

Cause Analysis: 

1. The bulging is caused by the spur of the punching hole being too small or the burr of the burring is too large.

2, it is not tight because the hole expansion is not in place.

3. There is a misalignment of the holes or a wrong way of twisting.

Solution: 

1. Change the punch with a large R angle.

Note: The burrs around the hole when the hole is turned over.

2, increase the pressure, the salad hole to deepen, switch to the big R angle punch.

3. Change the method of twisting and the reason for the hole misalignment.

10. Deformation of the workpiece after the stud is bent or bent

Cause Analysis: 

1. The workpiece is not broken when the product is processed.

2. The surface of the workpiece is not uniformly stressed or the pressure is too high.

Solution: 

1. When the stud is pressed, the workpiece should be flattened.

2. Make a support frame.

3. Re-adjust the pressure.

4. Increase the force range of the lower surface and reduce the range of force applied to the upper surface.

11, after the step is not parallel on both sides

Cause Analysis: 

1. The mold is not corrected.

2. The upper and lower mold gaskets are not adjusted well.

3. The choice of upper and lower die faces is different.

Solution: 

1. Re-calibrate the mold.

2. Increase or decrease the gasket. (For specific adjustment methods, see "Step Difference Processing Technology")

3, the mold is eccentric.

4. Replace the surface to make the surface of the upper and lower molds the same.

12, the product surface crease is too deep

Cause Analysis: 

1, the lower mold V slot is small

2. The R angle of the lower mold V groove is small.

3. The material is too soft.

Solution: 

1, using large V-groove processing

2, the use of large R angle mold processing 3, litter bending (mat steel sheet or superior glue)

13. The near bend is deformed after bending

Cause Analysis: 

During the bending process, the machine runs fast, and the upward bending speed during the deformation of the workpiece is greater than the speed at which the operator supports the movement of the workpiece.

Solution: 

1. Reduce the running speed of the machine

2. Increase the operator's hand support speed.

14, AL parts are prone to cracks

Cause Analysis: 

Because the AL material has a special crystal structure, it is easy to break in the direction of the parallel grain when bending.

Solution: 

1. When cutting, consider cutting the AL material in the vertical direction of the bend (even if the material is bent in the direction)

The lines are vertical.

2. Increase the upper mold R angle.

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Updated:2018-11-30 | Return
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