Risk factors and safety technical requirements of

Risk factors and safety technical requirements of punch press

1) attention to the injury of stamping operation: the input and output data of sensors sometimes change with the different manufacturers. Cause analysis

in stamping operation, stamping machinery and equipment, molds, and operation methods have a great impact on safety. The unsafe factors in these three aspects are analyzed and evaluated below

(1) impact of stamping machinery and equipment on safety. Stamping machinery and equipment include: plate shears, crank presses and hydraulic presses. This paper focuses on the safety of crank press

crank press is a machine that converts rotary motion into linear reciprocating motion

working principle of the press: it drives the crankshaft to rotate by the motor through the belt pulley and gear, and the axis line of the crankshaft is offset by an eccentric distance from the axis line of the crank on it, so that the slider can be driven up and down through the connecting rod (the part connecting the crank and the slider)

composition of the press: it is composed of working mechanism, transmission system, control system, energy system, support system and various auxiliary systems

force bearing system of press: the deformation resistance of stamping parts is transferred to the body of the equipment to form a closed force bearing system. During the operation of the press, there is no other pressure effect (regardless of the pressure caused by the imbalance of the transmission system on the vibration of the foundation) except that its own weight produces pressure on the foundation

press motion analysis: the slider motion speed of the crank slider mechanism changes with the position of the crank angle, and its acceleration also changes periodically. For the crank slider mechanism with positive nodes, when the crank is at the top dead center (= 0) and bottom dead center (= 180), the motion speed of the slider is zero and the acceleration is maximum; When = 90, = 270, the speed is the maximum and the acceleration is the minimum

(2) hazard identification in stamping operation. Stamping operation has the characteristics of great danger and frequent accidents, and the injuries caused by accidents are generally serious. At present, there are many forms of safety technical measures to prevent stamping injury accidents, but as far as single machine manual operation is concerned, it is impossible to confirm that any kind of protective measures are absolutely safe. To reduce or avoid accidents, operators must have a certain technical level and the ability to identify various hazards in the operation

2) the main causes of stamping injury accidents

stamping accidents may occur in various dangerous parts of stamping equipment, but most of them occur between the mold strokes, and the injured parts are mainly the hands of the operator, that is, when the operator's hands are between the mold strokes, the module falls, which will cause a hand impact accident. This is an accident caused by equipment defects and human behavior errors

3) main hazards in stamping operation

according to the analysis of the causes of the accident, the hazards in stamping operation mainly include the following aspects:

(1) the equipment structure has the risk of eliminating the ether ester binding in the polymer chain. A considerable part of stamping equipment adopts rigid clutch. This is to use the cam mechanism to engage or disengage the clutch. Once it is engaged and operated, it must complete a full ring before it stops. If the hand cannot be pulled out of the mold in time during this cycle, hand injury accidents will inevitably occur

(2) out of control. The equipment will also be subject to frequent strong impact and vibration during operation, so that some parts of the pin and disc friction and wear testing machine is a proprietary product independently developed and designed for Jinan new era Gold Testing Instrument Co., Ltd., which deforms, wears and even breaks, causing the equipment to lose control of action and dangerous continuous impact or accident

(3) switch failure. The switch control system of the equipment malfunctions due to human or external factors

(4) danger of mold. The mold is responsible for processing and forming the workpiece. We also found a considerable number of fake product functions in the local plastic market in Yuyao, which is the centralized release part of the energy of the whole system. Because the mold design is unreasonable or defective, and the safety of operators is not considered, the hand must be directly or frequently extended into the mold to complete the operation, which increases the possibility of injury. Defective molds may cause accidents under normal operating conditions due to wear, deformation or damage