At present, many enterprises still use simple manual operation methods when using punching machines for production, that is, directly loading and unloading parts into the mold cavity by hand. Moreover, a large number of punching machines are responsible for the manufacturing tasks of various products. In this case, if the punching machine equipment and mold do not have safety protection devices, it is highly likely to cause hand injuries. So, in the production of punching machines, strengthening protection and improving mechanization are important ways to prevent accidents from happening.

The technical measures for punch operation cover a wide range, including improving the punch operation method, reforming the mold structure, and achieving mechanical automation. The use of composite molds, continuous molds, and multi-station molds can all reduce processes, simplify processes, simplify operations, and reduce operator risks.

Using hand tools can avoid accidents caused by improper mold design and sudden equipment failures. Common tools include elastic forceps, specialized forceps, magnetic suction cups, forceps, pliers, hooks, etc.

Protective measures for the mold include setting up protective plates (covers) around the mold and improving the mold structure. Reduce the dangerous area of the mold and expand the space; Set up a mechanical discharge device to improve the reliability of various manual feeding single process molds without affecting the strength and product quality of the molds.

Setting up safety protection devices or using manual tools with low labor intensity and convenient and flexible use on stamping equipment and molds is also an effective measure to achieve stamping operations under current conditions. Such as using manual tools, mold protective covers, mechanical entry and exit devices, dual button switches, mechanical handles, push and pull devices, photoelectric automatic protection devices, etc. There are many forms of protective devices for stamping equipment, which can be divided into mechanical, button, photoelectric, inductive, etc. according to their structure.

The mechanical protective device has a simple structure and is easy to manufacture, but it has significant interference with the operation, and operators do not like to use it, resulting in relatively few applications.

The photoelectric protection device is composed of a set of photoelectric switches and a mechanical device. When the operator's hand enters the mold area, the beam of light is obstructed and an electrical signal is emitted, thereby achieving the goal of stopping the slider and preventing it from descending, ensuring the safety of the operator. There are two types of photoelectric protection devices: infrared photoelectric protection devices and incandescent photoelectric protection devices. Due to its convenient use and minimal interference with operations, photoelectric protection devices are widely used.

The contact protection device uses the contact rod as a sensing element to control the movement of the slider, and there are two types: normally open and normally closed. This protective device has a simple structure, low production cost, and convenient operation. Workers can connect multiple sets of devices in series while working. It is suitable for press machines equipped with friction clutches and press machines with modified rigid clutches.

Realizing the mechanization and automation of stamping operations is the fundamental way to ensure the safety of workers and equipment. Only achieving fully automated production of stamping, feeding, and picking is the technical measure to achieve stable production.

Practice has proven that using composite molds, multi-station continuous molds instead of single process dangerous molds, or setting mechanical feeding and discharging mechanisms on molds to achieve mechanization and automation can achieve the goal of improving product quality and production efficiency, reducing labor intensity, facilitating operation, and ensuring stability.

Protective devices are currently an effective protection device for the personal safety of stamping machine operators. They have better protection effects than protective barriers, mechanical handles, and other protective devices, avoiding accidents caused by improper operation or machine malfunctions during the production process. Suitable for high-performance punching machines, mechanical presses, hydraulic presses, film presses, shearing machines, industrial robots, packaging equipment, and other automation equipment, as well as for protecting or preventing theft in multiple areas.

The opposed photoelectric protection device refers to the photoelectric protection device where the light emitting unit and the light receiving unit are respectively located in the light emitting device and the light receiving device. The light emitted by the light emitting unit is directly directed to the light receiving unit, forming a protective light curtain. The radiation protection device consists of five parts: a controller, a light emitting device, a light receiving device, a light emitting transmission line, and a light receiving transmission line, as shown in Figure 1.

At present, many enterprises still follow a simple manual operation method when using stamping methods for production, that is, directly loading parts from the mold cavity by hand, and a large number of stamping equipment is responsible for the manufacturing tasks of various products or processes. In this case, if the stamping equipment and molds do not have protective devices, it is highly likely to cause hand injuries. Therefore, strengthening protection, management, and improving mechanization in stamping production is an important task to prevent accidents from occurring.

1. Analysis of injury caused by stamping operations

The causes of injury accidents caused by stamping operations include five factors: personnel, equipment, molds, processes, and environment.

(1) People are the central link in achieving stable production

Stamping production is a continuous and repetitive operation, and most small and medium-sized enterprises basically use manual operations. Due to the demand for high speed and production efficiency, a shift requires thousands of repeated hand deliveries and product retrieval, which consumes a lot of physical energy. Long working hours can easily cause operators (especially young workers) to have paralyzed thoughts, leading to errors and accidents. At the same time, leaders at all levels have improper production organization arrangements, lax rules and regulations for stable production, poor management, command violations, and a lack of emphasis on stable production. In addition, operators who violate regulations, take risks, are impatient, arrogant, and hasty, as well as large stamping machines operated by multiple people collectively, are prone to accidents if cooperation is not coordinated enough.

(2) The impact of stamping equipment on safety production

Stamping equipment has a significant impact on production. The main causes of accidents include defects in the punching machine itself, lack of protective devices, insufficient flexibility and reliability of the clutch and brake, sudden loss of control of the electrical control structure resulting in continuous punching, and defects in accessory tools.

(3) The impact of unsafe factors in stamping molds on safety production

The unstable state of the mold directly affects the personal safety of the operators and the normal progress of stamping production. If in the process of designing the structure of the stamping die, neither convenient tools nor factors such as ensuring the convenience of feeding, feeding, discharging, and cleaning waste are taken into account, the operator's hands will stay in the closed area of the die for too long, which will inevitably cause accidents. Therefore, scientific mold design is extremely important.

(4) The impact of process documents on safety production

Process documents are not only the basis for production, but also an important basis for implementing process discipline. A typical document that records the stamping process is the process specification, which should include the entire process from the preparation of raw materials to the production of finished products.

However, there is a serious loophole in the process documents, which is that most of the process documents do not clearly specify requirements and technical measures. In addition, the existing stamping regulations are not perfect, such as the "regulations" formulated by factories, which generally include all stamping parts. Although they can reflect the commonalities of stamping processing, they cannot reflect its characteristics. The "regulations" often only generally state "generally using safety tools" and "hands are not allowed to operate inside the mold", but there are no specific and clear technical measures for the different characteristics of each component. As a result, in the actual production process, there is a long-term situation of hands operating inside the mold, making safety management mere formality, and operators ignore the use of devices and tools and risk operations, resulting in accidents.

(5) The impact of the environment on operators

The impact of stamping environment on operators is also very important. If the work site is narrow, the products are not stacked neatly, the lighting is insufficient, the ventilation is poor, coupled with noise and high or low ambient temperature, accidents can be caused.

2. Preventive measures for stamping accidents

Based on the analysis of the above reasons, there are various preventive measures to prevent stamping accidents. Firstly, it is necessary to strengthen management measures, followed by adopting technical measures, both of which are indispensable.

(1) Safety management measures for stamping operations

The management of stamping operations is a comprehensive task that requires not only technical measures, but also strict and sound management methods. Stamping operation management involves process, mold, equipment management, production plan management, and technical education management. If the process discipline is not strict, the mold management is not good, there are many hidden dangers of equipment accidents, the organization of production is not qualified, the operation level is low, and the discipline is lax, injury accidents will continue to occur.

Promote evaluation activities, establish and improve stable production rules and regulations, especially the implementation of the "safety production responsibility system", so that each employee can clarify their responsibilities, strictly implement stamping operation procedures, strengthen management work, and prevent the occurrence of liability accidents.

Doing a good job in educating employees is an extremely effective way to reduce stamping accidents. Enterprises often provide ideological and technical knowledge education to their employees, so that stamping workers, technicians, and production management personnel can firmly establish their thinking and proficiently master the operation technology of stamping equipment, molds, and protective devices, which can avoid and reduce the occurrence of accidents.

It is necessary to strengthen the management of stamping processes and incorporate technical measures and requirements into process documents. It can not only ensure the implementation of various technical measures and achieve effective production, but also clarify the production responsibility system of process technicians. If the production status, number, equipped tools and devices, name, number, etc. of the stamping die are indicated on the process card, and specific and clear process documents are used as the production basis, accidents caused by lack of rules or unclear process discipline can be effectively prevented.

In addition, process technicians must regularly understand and master the problems that exist in the production process, and continuously improve process technology methods.

In the management process of stamping molds, it is necessary to first conduct regular inspections and maintenance, and then distinguish the molds by color codes based on the degree of threat they pose to people. Red represents dangerous molds, yellow represents safe molds, and green represents automatic molds.

In the management of stamping equipment, the first step is to establish an equipment maintenance system, ensuring regular maintenance of equipment and devices. Before operation, it is necessary to carefully inspect the operating system, electrical appliances, and main fasteners of the equipment, observe whether they are operating normally, and strictly prohibit the equipment from operating with defects.

In the production management process of stamping operations, it is necessary to strengthen production planning and scheduling work, reasonably formulate production schedules and deadlines based on product structure and production scale, ensure balanced and orderly production, and avoid accidents caused by overtime work.

(2) Safety technical measures for stamping operations

The technical measures for stamping operations cover a wide range, including improving the stamping operation method, reforming the die structure, and achieving mechanical automation. The use of composite molds, continuous molds, and multi-station molds can all reduce processes, simplify processes, simplify operations, and reduce operator risks.

Hand safety tools. Using hand tools can avoid accidents caused by improper mold design and sudden equipment failures.

Common tools include elastic forceps, specialized forceps, magnetic suction cups, forceps, pliers, hooks, etc.

Protective measures for molds. Including setting up protection around the mold and improving the mold structure. Improving the dangerous area of the mold and expanding the space; Set up a mechanical discharge device. On the premise of not affecting the strength and product quality of the mold, various single process molds with manual feeding will be improved to improve stability.

Setting protective devices on stamping equipment and molds or using manual tools with low labor intensity and convenient and flexible use is also an effective measure to achieve large-scale protection in stamping operations under current conditions.

Protective devices for stamping equipment. There are many forms of protective devices for stamping equipment, which can be divided into mechanical, button, photoelectric, inductive, etc. according to their structure.

The photoelectric device is composed of a set of photoelectric protectors and a mechanical device. When the operator's hand enters the mold area, the beam of light is blocked and an electrical signal is emitted, thus achieving the goal of stopping the slider from moving down and ensuring the operator's safety. Due to the convenient use of photoelectric protection devices, they have little interference with operations and are widely used.

Name of photoelectric protective devices in the product industry:

Protector, photoelectric protector, safety grating, punching machine protector, safety light curtain, photoelectric eye, photoelectric protector, punching machine protector, infrared electric eye, machine tool protector, mechanical equipment protector, assembly line detection device, protective alarm device, finger protector, finger protector, finger cutter, finger cutter, and two hand protector.

(3) Improve the working environment and strengthen self-protection measures

According to the evaluation standards and on-site management regulations, achieving reasonable equipment layout, product stacking, coupled with reasonable lighting, suitable temperature, and a good on-site environment, can reduce accidents.