01, information from the waste conditions
The waste is essentially a flexographic image of the forming hole. That is, the same location is opposite. By checking the waste, you can judge whether the upper and lower die gaps are correct. If the gap is too large, the waste will have rough, ups and downs and a narrow light belt area. The larger the gap, the greater the angle of the fracture surface and the light belt region. If the gap is too small, the waste will present a small angle break surface and a wide light belt area.
Excessive gaps form holes with larger curls and edge tear, and a slight edge protruding slightly. Too small gap forming tape slightly roller and large angular tear, resulting in a cross section or less perpendicular to the surface of the material.
An ideal waste should have a reasonable collapse angle and a uniform light belt. This can keep the punching force and form a tidy round hole in which a very small burr is formed. From this point of view, extending the mold life by increasing the gap is to sacrifice the quality of the finished hole.
02, the selection of the mold gap
The gap of the mold is related to the type and thickness of the punched material. The unreasonable gap can result in the following problems:
1) If the gap is too large, the burrs of the stamped workpiece are relatively large and the stamped quality is poor. If the gap is small, although the quality of the punch is better, the wear of the mold is more serious, greatly reduces the life of the mold, and is easily broken.
2) The gap is too large or too small to generate adhesion on the punch material, resulting in a stamping. Excessive gaps are easy to form a vacuum between the bottom surface of the punch and the sheets.
3) Reasonable gap can extend the life of the mold, the unloading effect is good, reduce the burr and turn, the sheet is kept clean, the aperture does not scratch the film, reduce the number of edges, keep the plate straight, The punching is accurate.
Refer to the following table to select the mold clearance (percentage data in the table)
03, how to improve the life of the mold
For users, improve the life of the mold can greatly reduce stamping costs. Factors affecting the life of the mold:
1) The type of material and thickness
2) Whether to select a reasonable lower die gap
3) the structure of the mold
4) Whether there is a good lubrication when the material is stamped
5) Whether the mold is specially treated
6) such as titanium plating, carbonitridide
8) Reasonable use of the gasket
9) Whether the oblique blade mold is properly adopted
10) Whether the machine tool has been worn
04, the problem of stamping special dimension should pay attention to
1) Minimum aperture
Use special punches with φ0.8-φ1.6 ranges.
2) When the thick plate punch is peripheral, use a large number of molds relative to the machining aperture. Note: At this point, if the usual size mold is used, the damage of the punch thread is caused.
Example 1, as follows of the processing conditions, the processing aperture corresponds to the A station mold, but use the B-station mold.
Example 2, as follows of the processing conditions of the following table, the processing aperture corresponds to the B-station mold, but use the C station mold.
3) The ratio of the punch cutting edge, the minimum width and length should generally should not be less than 1:10.
Example 3, a rectangular punch, a length of 80 mm, and the cutting edge width is most suitable.
4) The relationship between the minimum dimension and the thickness of the punch cutting edge. It is recommended that the minimum size of the punch blade is twice the thickness of the plate thickness.
05, mold blade blade
(1) Importance of mold edge mill
Regular blade mill is a punched quality consistency guarantee. Regular edging molds not only improve the life of the mold but also improve the service life of the machine, and master the correct edge grinding.
(2) The mold requires a specific feature of the edge grinding
For the blade grinding of the mold, there is no strict strike number to determine if the edge grinding is required. It is mainly dependent on the sharp level of the cutting. It is mainly determined by the following three factors:
1) Check the fillet of the blade, if the radius of the rounded angle reaches R0.1 mm (the maximum R value must not exceed 0.25 mm), it needs to be sharpened.
2) Check the punching quality, whether there is a large burry generation.
3) Decision is required to be sharpened by the noise of the machine stamping. If the noise is abnormal when the same panel is stamped, the punch is already blunt and needs to be sharpened.
Note: The edge of the blade is rounded or the rear of the blade is rough, and the edge grinding is also considered. (3) Method of blade blade
The mold of the mold has a variety of methods, and a special blade mill can also be implemented on a planar grinder. The frequency of punching and lower mold blade mills is generally 4: 1, and then adjust the mold height after edding.
1) The harm of incorrect edge grinding methods: incorrect blade grinding will exacerbate the rapid destruction of the mold blade, resulting in a significant reduction in the strike of each blade mill.
2) The benefits of the correct edge grinding method: Regular Edge Mold, punchingThe quality and accuracy can remain stable. The blade of the mold is less than the lower, longer life.
(4) Blade Rule
The following factors should be considered when the mold is wrinkled:
1) The blade reircum is in the case of R0.1-0.25 mm. To see the sharp level of the cutting edge.
2) The surface of the grinding wheel should be cleaned.
3) It is recommended to use a loose, coarse grain, and a soft wheel. Such as WA46KV
4) Each time the grinding amount (eating the bladder) should not exceed 0.013 mm, the grinding amount will cause overheating of the mold surface, which is equivalent to annealing, the mold is soft, greatly reduced the mold. life.
5) Adfficient of coolant must be added when the edge grinding.
6) The grinding should be guaranteed to secure the punch and the lower mold fixation and use a dedicated tool fixture.
7) The blade grinding amount of the mold is certain, if the value is reached, the punch should be scrapped. If you continue to use, it is easy to cause damage to the mold and the machine.
8) After the edge grinding, the edges should be treated with oil, and remove excess sharp ridges.
9) After the edge grinding, clean it clean, demagnetize, and oil.
Note: The size of the mold blade is mainly depending on the thickness of the stamped sheet.
06. Before using the punch
1) Wipe it with a clean rag.
2) Wharf or dents should not occur when the surface is stored.
3) Oil rust.
1) Thoroughly clean the mold.
2) Check if there is shaving and dent. If there is, remove it with oil.
3) Outstanding oil.
(3) When the installation punch is in the upper mold, it should be considered
1) Cleaning the punch and give the oil on the oil.
2) Insert the punch into the bottom of the upper mold in the large station mold, and cannot force. Can’t use a nylon hammer. When installing, the punch cannot be fixed by tighten the bolts on the mold set, and only the bolts can only be tightened after the punch is properly positioned.
(4) Installing the upper mold combination into the transfer tower
If it is desired to extend the life of the mold, the gap between the upper mold diameter and the turret bore is as small as possible. So please take care of the following procedures.
1) Clean the keyway of the turret hole and the inner diameter and oil.
2) Adjust the keyway of the mold guide to make it a key to the turret pore.
3) Engage the upper mold kitInsert the tower bore directly, be careful not to have any tilt. The upper mold guide should slide into the turret hole by weight.
4) If the upper mold is tilted, it can be gently tapped with a soft material tool such as a nylon hammer. Repeatedly tapping until the upper mold guide slides into the correct position on its weight.
Note: You cannot use force to be on the molded sleeve diameter, which can only be loaded on top of the punch. You can’t knock on the top of the mold, so as not to damage the turret holes, shorten the life of individual stations.
07, the maintenance of the mold
If the punch is bitten by the material, it can’t be taken, please check it as follows. 1) The red edge grinding of the punch and the lower mold. The sharp cut surface can be processed with a beautiful cut surface, and the cutting is blunt, then additional punching force is required, and the workpiece is rough, producing a large resistance, resulting in a punch by the material.
2) The gap of the mold. If the gap of the mold is not suitable for the opposite plate, the punch requires a large demolding force when the material is detached. If this is the reason why the punch is bitten by the material, replace the lower mold of reasonable gap.
3) The state of the processing material. When the material is stained, or when there is dirt, the dirty thing is attached to the mold so that the punch is bitten by the material and cannot be processed.
4) Amountable material. After the warped material is finished, the punch is clamped so that the punch is bitten. If there is warped material, please flatter and then processed.
5, excessive use of the spring. The spring is fatigued. Please pay attention to check the performance of the spring.
08, the oil content and the conditions of the injection of the injection of the material are determined. Cold-rolled steel sheet, the resistant steel plate, such as the corrosion-resistant steel plate, to give the mold oil, oil injection point, the contact surface, the mold, the tool body and the guide sleeve, the lower mold, etc. Oil light oil.
There is a material of rust, and the rust microfringe is inhaled between the punch and the guide sleeve, so that the punch cannot be slid freely in the guide sleeve, in which case if oil, It will make rust, so that it is rushing this material, the opposite should be wiped with oil, decompose once a month, use steam (Chai) oil, remove the dirt of the lower mold, re-assemble the wipe again clean. This ensures that the mold has good lubrication performance.
09, often occurring problems and solutions during molding
Problem 1, sheet from the jaws
Problem 2, the mold wear is serious
Question three, punch strip and punch adhesion
Question four, waste rebound
Problem 5, unloading difficult
problem 6, stamping noise
10, other precautions and suggestions
(1) Precautions for special molding tools
1) Different models of machine slides are different, so pay attention to the adjustment of the molded mold closure.
2) Be sure to ensure that it is fully, it needs to be carefully adjusted. It is best not to exceed 0.15 mm each time, if the amount of adjustment is too large, it is easy to cause damage to the machine and the damage of the mold.
3) For stretching, use light spring assemblies to prevent torn of the sheet, or difficult to remove uneven disinsters due to uniform deformation.
4) Install the ball-type support mold around the molding die to prevent the sheet from tilting.
5) The forming position should be as far away from the clamp.
6) The molding process is best implemented in the final implementation of the machining program.
7) Be sure to ensure good lubrication of the sheet. 8) Pay attention to the problem of special molding tools when ordering, if the distance between the two molding is relatively close, please be sure to communicate with the company’s salesperson. 9) Because the molding tool requires a longer unloading time, it is necessary to use low speed when molding, preferably delay.
(2) Precautions for using a rectangular cutting knife
1) The step Metal Stamping Tooling is as large as possible, 80% of the entire cutter length.
2) It is best to achieve a jumping step by programming.
3) It is recommended to use a slope blade mold.
(3) How to punch the diameter of 114.3 mm in the production process without exceeding the machine’s magicity. Such large holes will exceed the upper limit of the machine’s magic, especially for high shear strength materials. This problem can solve this problem with multiple punching methods. Use small-size molds along the magnifier of the large circle to reduce half or more of the stamping force, which may be done in most molds in the mold you already have.
(4) A simple method of rolling a circular hole
The mold of this convex lens can be made into the radius size of you. If the aperture exceeds the punch of the punch, we recommend the (a) scheme. Use this mold to rush out of the circle. If the aperture can be rushed into the scope of the punch, a radial mold and a convex lens mold can punch the required hole within four times without rotating the mold (B)
(5) Finally, it is molded down
When the forming mold is elected, it should be avoided, because this will take it tooMulti-vertical space and resulting in additional flat or curved plates. Down molding may also fall into the lower mold, and then pulled out the tower, however, if the down-shaped is a unique process selection, it should be used as the last step of the plate. (6) Preventing material distortion
If you need to punch a large amount of holes on the plate, the sheet cannot be kept flat, and the cause may be a stress stress accumulation. When cutting a hole, the peripheral material peripheral of the hole is downward, and the surface of the sheet is increased. The downhole movement also results in an increase in surface compression stress under the plate. For a small amount of holes, the results are not obvious, but with the increase of the number of punching, the stress and the compressive stress are doubled until the sheet is deformable.
One of the methods to eliminate this deformation is to punish every other hole and then return to the remaining holes. This produces the same stress on the sheet, but the disintegration of tall stress / compressive stress accumulation is caused to continuously. So, the first batch of holes shared the second batch of deformation effect.
(7) If your stainless steel flaps
administer the high quality forming lubricant to the material prior to manufacturing, this can make the material to be separated from the mold, in forming The surface of the lower mold is moving smoothly. This gives a better opportunity to distribute the stress generated when bending and stretched, preventing wear on the bottom of the flange hole on the edge of the molded flange. (8) Some suggestions overcome difficulties
1) Use the punch with thin core cladding.
2) Increase the lower die gap.
3) Check the fatigue of the spring.
4) Use the overloaded mold.
5) Appropriate use of oblique blade molds.
6) Lubricating plates.
7) The large station mold requires mounting polyuretolin unloading head.
(9) Causes the main cause of waste of the waste
1) sharp extent of the cutting edge. The larger the rounded corner of the blade, the easier it is to cause waste to rebound.
2) The mold amount of the mold. When each station mold is stamped, the requirements of the insertion die are certain, small insertion, which is easy to cause waste.
3) Whether the gap of the mold is reasonable. The unreasonable mold clearance is easy to cause waste.
4) Whether the surface of the processed sheet has oil.
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