How to prevent punching machine injury

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How to prevent stamping machinery injury

in the pressure processing industry, the nature of object strike injury accidents is very serious. There are three reasons:

1 Pressure processing machinery, such as mechanical presses, hydraulic presses, forging hammers, shear punches and so on, all rely on huge energy to work

2. The causative or harmful substances causing injury are mostly caused by molds, tooling and tools. It is difficult to be effective by the protection of the equipment itself. Generally, technical measures should be taken

3. The way of injury is irregular, and it is difficult to determine the direction of the flying out and ejection of the cause and cause of injury. It can be seen that the object strike injury accident in the pressure processing industry has its own characteristics, and the preventive measures must be targeted, otherwise it is difficult to be effective

causes of object strike

the main factors causing object strike injury during pressure processing are as follows:

1 Stress concentration caused by improper use or unreasonable structure finally leads to die damage and die fragments flying out

2. Defects of the module itself, such as surface cracks, fatigue cracks, too large hardness, etc., cause mold fragments to fly out

3. Improper selection of mold and tool materials causes local damage, flying out and ejection of mold and tool

4. The mold does not match the equipment, the mold body is deformed and damaged, and fragments fly out

5. The gap was not adjusted in time, resulting in the collapse of molds and tools and the ejection of fragments

preventive measures

according to the above cause analysis, the internal cause of object strike is caused by fragments flying out or popping out after the overall or local damage of molds and tools, and the focus of prevention is also here. Most of the dies and tool materials used in pressure processing to make large printed products basically free from edge warping and cracking are alloy steel, carbon tool steel and cemented carbide. They all have a common feature: high strength and hardness, relatively low plastic toughness, which is quite beneficial to metal deformation but detrimental to the safety of operators. How can we balance the two? Based on years of experience, the author believes that it is effective to find preventive measures by improving the process method. The method is simple and cost-effective. A universal insurance financial product named "yu'ebao user exclusive rights phase 2" began to be sold on yu'ebao official, triggering a rush purchase. The process improvement is mainly based on good after-sales service and based on the market to reduce stress concentration and improve the plasticity of molds and tools. In general, the more serious the stress concentration is, the more likely it is to cause local die damage; The worse the plasticity of the module, the easier it is to cause mold cracks. The following methods are available to reduce stress concentration and improve plasticity:

improve plasticity from the perspective of improving the internal performance of tools and dies

1 For the molds and tools used for a period of time, preheating treatment shall be carried out regularly, and the preheating temperature shall be controlled below the phase transformation temperature of the metal, which has little impact on the strength, but can eliminate the stress concentration and improve the plasticity. Generally, the temperature shall be controlled at 300 ℃ ~ 400 ℃, and then the surface shall be inspected by visual inspection or flaw detection to eliminate relevant defects

2. In cold seasons (room temperature is lower than 10 ℃), preheat the mold, tools, hammers and sliding blocks at a temperature of 200 ℃ ~ 300 ℃ every day before commencement to reduce the deformation resistance and enhance their plasticity

3. The temperature of cooling water shall not be too low for the cooling of dies and tools used for hot processing, and quenching shall not be used. Generally, the temperature of cooling water shall be greater than 50 ℃

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