The impact of stamping die structure on safety

The stamping die is the main process equipment for stamping processing, and the stamping parts are completed by the relative movement of the upper and lower dies. During processing, due to the constant separation and recombination between the upper and lower molds, if the operator's fingers keep entering or staying in the mold closed area, it will pose a serious threat to his personal safety.

(1) The main parts, functions and safety requirements of the mold

1. The convex and concave die of the working part is the working part that directly makes the blank shape. Therefore, it is the key part of 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 damaged during the stamping process. (2) Appropriate requirements should be made for its materials and heat treatment to prevent brittleness due to high hardness.

2. Positioning parts Positioning parts are the parts that determine the installation position of the blank. There are positioning pins (plates), stop pins (plates), guide pins, guide plates, side cutters, side presses, etc. When designing positioning parts, it should be considered convenient for operation, there should be no over-positioning, and the position should be easy to observe. It is best to use forward positioning, outer profile positioning and guiding pin positioning.

3. Pressing, unloading and discharging parts Pressing parts include blank holders, blank holders, etc.

The blank holder can exert pressure on the drawn blank, thereby preventing the blank from arching and forming wrinkles under the action of tangential pressure. The function of the holding plate is to prevent the blank from moving and bouncing. The function of ejector and discharge plate is to facilitate the ejection of parts and the cleaning of waste materials. They are supported by springs, rubber and air cushion push rods on the equipment, and can move up and down. The ejector parts should be designed with sufficient ejection force and movement should be limited. The unloading board should minimize the closed area or mill out empty hand slots in the operating position. The exposed unloading plate shall be surrounded by protective plates to prevent fingers from entering or foreign objects from entering, and the edges and corners of the exposed surface shall be blunt.

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 dies have a precise fit clearance during the stamping work. Therefore, the clearance between the guide post and the guide sleeve should be smaller than the blanking clearance. The guide post is set on the lower mold base, and the upper end surface of the guide post is at least 5 to 10 mm above the top surface of the upper template when the stroke bottom dead center. The guide post should be arranged far away from the module and the pressing plate, so that the operator's arm does not need to go over the guide post to feed and take materials.

5. Supporting and clamping parts include upper and lower templates, mold handles, convex and concave mold fixing plates, backing plates, stoppers, etc. The upper and lower templates are the basic parts of the die, and various other parts are respectively installed and fixed on it. The plane size of the template, especially the front and back direction should be compatible with the workpiece, too large or too small is not conducive to operation.

Some molds (blanking, punching molds) need to set up a backing plate under the mold base for the convenience of parting. At this time, it is better to connect the backing plate and the template with screws, and the thickness of the two backing plates should be absolutely equal. The spacing of the backing plates is subject to the parts that can be delivered, and should not be too large to prevent the template from breaking.

6. Fastening parts include screws, nuts, springs, pins, washers, etc., generally standard parts are used. There are a lot of standard parts of stamping dies, and the design and selection should ensure the needs of tightening and elastic ejection, avoiding the fasteners from being exposed on the surface operation position, and preventing hand injury and hindering operation.

(2) The safety points of mold design

The structure should try to ensure the convenience of feeding, ordering, discharging, and cleaning up waste materials. 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 must manually enter the mold, he should reduce the scope of the mold as much as possible, shorten the time that a certain part of the body stays in the mold as much as possible, and clarify the danger zone of the mold and provide 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 have anti-loose measures to avoid accidental injury to the operator.

It is not allowed to cause waste or workpiece missiles during processing, which will affect the attention of the operator or even hurt the operator. In addition, it is necessary to avoid cuts from the burrs of the blanking parts. The operator is not allowed to have too much movement range during the punching operation, and avoid the posture that makes the body lose stability. Excessive and difficult actions during homework are not allowed. Should try to avoid strong noise and vibration during stamping processing. The mold design should indicate the mold weight on the general drawing to facilitate installation and ensure safety. Lifting and handling measures should be adopted for the processing of parts over 20 kg to reduce labor intensity. When assembling and disassembling mold parts, it should be convenient and safe to avoid pinching or cutting hands. The mold should be easy to disassemble and store. In short, even minor problems in the mold will affect safety. Only by analyzing the specific problems in each operation can the safety precautions in the mold be put forward.