Structural safety impact of stamping dies

The stamping die is the main process equipment for stamping, and the stamping part is completed by the relative movement of the upper and lower Molds. Due to the continuous separation between the upper and lower molds during processing, if the fingers of the operator continuously enter or stay in the closed area of the mold, it will pose a serious threat to their personal safety.
(1) Main parts, functions and safety requirements of the mold

1. Working parts The convex and concave molds are working parts that directly form the blank. Therefore, it is a key part on the mold. The convex and concave mold is not only precise but also complex. It should meet the following requirements: (1) It should have sufficient strength and cannot be broken or broken during the stamping process; (2) It should have appropriate requirements for its material and heat treatment to prevent the hardness from being too high and brittle. crack.

2. Positioning parts The positioning parts are parts for determining the installation position of the blank, and there are positioning pins (plates), retaining pins (plates), guiding pins, guide plates, fixed side blades, side pressure devices and the like. When designing the positioning parts, it should be considered convenient to operate. There should be no over-positioning, and the position should be easy to observe. It is best to use forward push positioning, external positioning and guiding pin positioning.

3. Pressing, unloading and discharging parts Pressing parts have pressure ring, pressure plate and so on.

The beading ring can pressurize the blanking force to prevent the blank from arching under the action of tangential pressure to form wrinkles. The function of the pressure plate is to prevent the blank from moving and bounce. The function of the ejector and the discharge plate is to facilitate the ejection and cleaning of the waste. They are supported by springs, rubber and air cushion pushers on the equipment and can be moved up and down. The ejector should be designed with sufficient ejection force and limited movement. The stripper plate should be as small as possible to close the closed area or to mill the empty hand groove in the operating position. A protective plate shall be provided around the exposed discharge plate to prevent fingers from entering or foreign objects from entering, and the exposed surface edges should be dull.

4. Guide parts Guide posts and guide sleeves are the most widely used guide parts. Its function is to ensure that the convex and concave molds have a precise fit clearance during the stamping work. Therefore, the gap between the guide post and the guide bushing should be smaller than the punching clearance. The guide post is arranged on the lower die holder, and the upper end face of the guide post is at least 5 to 10 mm above the top surface of the upper die plate when the stroke is dead. The guide post should be placed away from the module and the pressure plate so that the operator's arm does not need to feed over the guide column.

5. Supporting and clamping parts It includes upper and lower stencils, mold shanks, convex and concave mold fixing plates, backing plates, stoppers and the like. The upper and lower stencils are the basic parts of the dies, and various other parts are separately mounted and fixed. The plane size of the template, especially the front and rear direction, should be compatible with the workpiece. Too large or too small is not conducive to operation.

Some molds (falling and punching molds) need to be placed under the mold base for the convenience of the output. At this time, the backing plate is preferably screwed together with the formwork, and the thickness of the two backing plates should be absolutely equal. The spacing of the pads should be based on the output, not too large, so as to avoid the template from breaking.

6. Fastening parts It includes screws, nuts, springs, pins, washers, etc., and standard parts are generally used. The standard parts of the stamping die are used in a large amount. When designing, the requirements of fastening and elastic ejection should be ensured, and the fasteners should be exposed to the surface operation position to prevent the hand from being injured and hindering the operation.

(2) Safety points of mold design

The structure should ensure the convenience of feeding, setting, discharging and cleaning waste. For the processing of small parts, it is strictly forbidden for the operator's fingers, wrists or other parts of the body to extend into the mold area; for the processing of large parts, if the operator has to manually work in the mold, the range of the mold should be reduced as much as possible. Minimize the time that a part of the body stays in the mold, and clarify the range of the mold danger zone, equipped with the necessary protective measures and devices.

The various parts on the mold should have sufficient strength and rigidity to prevent damage and deformation during use. The fastening parts should be protected against loosening to avoid accidental injury to the operator.

It is not allowed to cause waste or workpiece missiles during processing, affecting the operator's attention and even injuring the operator. Also, avoid punching the burrs and cutting the hands. The operator is not allowed to have an excessive range of motion during the punching operation, avoiding the posture that causes the body to lose stability; it is not allowed to have excessive and difficult movements during the operation. Try to avoid strong noise and vibration during stamping. The mold design should indicate the weight of the mold on the general drawing for easy installation and safety. More than 20 kilograms of parts should be processed with lifting and lifting measures to reduce labor intensity. It is convenient and safe to assemble and disassemble the mold parts, avoiding the possibility of pinching or cutting hands; the mold should be easy to disassemble and store. In short, even subtle problems in the mold will affect safety. Only by analyzing the specific problems in each job can the safety precautions in the mold be presented.