The reason and preventive measures of cutting material of blank holder die in Stamping parts processing
The trimming sequence abrasive tool for stamping parts processing is generally very prone to cutting of the upper die during the adjustment process. The key reasons are:
- 1. The pressure core cannot have pressure parts and material return: the pressure core has uneven bearing capacity, and there are gaps in the guidance, and the material will not be returned if it is stuck;
- 2. The core-pressing force is insufficient after the edge-pressing;
- 3. After pressing the edge, the product deforms and gets stuck in the pressing core.
The improvement and precautionary measures for repairing edge material jams are as follows:
1. Solve difficulties
- 1) In view of the situation that the pressure core is stuck and cannot be returned normally due to the uneven bearing force of the pressure core and the guiding skew, the gap between the reamer and the sliding guide surface can be adjusted.
- 2) The spring-yellow arrangement position and the specifications of dismantling and replacing springs, etc. ensure that the bearing force is even.
- 3) Guidance of the pressure core: the guiding of the pressure core is mainly to ensure the gap between the pressure core and the knife edge of the cavity, and the general value is 0.5 mm.
- 4) Core pressing stroke arrangement: The pressing core stroke arrangement stipulates that the pressing core should pre-tension the product before the knife edge is cut; the cutting before the product is clamped can easily lead to product deformation, tearing of the blank holder, jamming, etc. Before the cavity touches the metal stamping parts, the pre-stressed tensioning stroke of the pressure core is arranged ≥ 10 mm.
2. Solve difficulties
- 1) The withdrawal force changes when the board is thicker and has a different appearance, generally 4-20% of the blanking force.
- 2) For stamping parts processing, when there is vertical cutting in the blank holder, it is necessary to increase the withdrawal force.
- 3) The force source selects bombs, and the force source layout is close to the working position; for the requirements of the return force is not large, you can choose to use polyurethane materials to show the return force.
- 4) Calculation of force. The working pressure of spring yellow F=kL, k is related to the cross-section of spring yellow, inner and outer diameter specifications and tool steel material characteristics, L is the deformation variable; the working pressure of the nitrogen spring almost changes linearly, with no torque, the original pressure is too large, It occupies the advantages of small indoor space, long life, and 40 times per minute response frequency.
3. For the problem
- 1) Abrasives cannot be lapped in time to cause product deformation, and abrasive tools can be lapped to deal with product deformation problems and jamming conditions.
- 2) Add elastic ejector pins in the press core to set the product down the press core.
The stamping machine used in the processing of stamping parts is organized by the motor through the transmission mechanism to promote the work organization, which releases the processing technology force to the Stamping Die product workpiece. The transmission mechanism is a speed reduction organization of synchronous belt transmission and transmission gears; the work organization is divided into a spiral organization , Crank connecting rod organization and hydraulic cylinder;
Stamping machines used in stamping parts processing are divided into three categories: screw presses, crank presses and four-column hydraulic presses; crank presses are also called mechanical presses;
The screw press has no fixed bottom dead center, which can severely blow molding for large die forgings several times, and can carry out single pick, continuous and inch movement. The vibration force is related to the deformation of the product workpiece. The vibration force is small when the deformation is large, and the vibration force is large when the deformation is small (such as cold shock). At this level, it is similar to a forging hammer. However, its vibration force is closed according to the sound card rack, so it is stable in work, and the vibration is much smaller than that of a forging hammer, and it does not need a very large basic.
The lower side of the punching machine is equipped with cast steel injection equipment. The screw press has the functions of a variety of forging equipment such as die forging hammers and mechanical presses. It has strong versatility and can be used for free forging, cold stamping, Deep Drawing and other processing techniques. In addition, the screw press is simple in structure and easy to manufacture, so it is widely used.
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