The most popular way to change the old press

2022-07-25
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Let the old press "look new"

through the technical transformation of the old machine tools, they can meet the requirements of new technical specifications and safety regulations. Such transformation is very valuable

there are many old-fashioned presses in many plate processing plants. Their mechanical performance is still very good, but the level of safety protection has fallen behind the requirements of the times. For these old machine tools, the most important thing is to transform the safety control system still used in the electrical control cabinet, or replace it with new products. Therefore, it is necessary for the managers of these old machine tools and equipment to make decisions, deal with these old equipment, or transform them into a modern safety protection system and continue production

for most presses, it is very worthwhile to carry out general overhaul or modern technical transformation. In other words, the mechanical worn parts will be repaired or replaced, and the electrical control system will be updated to meet the requirements of modern safety technology. In this process, we can also take some technical transformation measures to improve the production capacity. In this way, not only the modern safety protection technology can be used, but also the production capacity of the machine tool can be improved

through the modern technical transformation of an old eccentric press, this paper wants to explain a problem: how to improve the mechanical function of the old machine tool through the overhaul of the electrical control cabinet and the renewal of the safety protection technology, and the process technology is more in line with the requirements of modernization

because the model of this eccentric press is too old, we can't buy the accessories for the safety protection electrical system used.

the supply of spare parts is a problem.

a mechanical processing plant in Finland has many PE 63T old eccentric presses produced in Hungary. Because these presses are too old, it is impossible to buy the accessories of the safety protection electrical system used. At the same time, the safety protection performance of these old presses can not meet the requirements of EU modern safety protection technical specification 89/655/ewg (minimum safety and health protection regulations for enterprise workers when using production tools). For the production tasks to be completed by the eccentric press, the machine bed and mechanical systems such as the diameter limitation of the collet that can hold the sample are not wrong, and can meet the processing requirements. When looking for a suitable service provider for the modernization of old equipment, they found noritek oy company located in Helsinki City

after the first field survey and condition detection of the equipment, noritek oy company came to the conclusion that the mechanical parts of the press are in good condition, and the electrical control cabinet really needs to be repaired and updated. As the equipment is too old, it is impossible to buy Electrical maintenance accessories, so they decided to comprehensively update the electrical control system of the eccentric press, that is to say, a new electrical control cabinet is required

the renovation of the electrical system requires a new electrical control cabinet

for easy assignment

. The original relay and contactor protection system of the press are replaced by new electronic control components. In the upgraded electrical control cabinet, except for the power control components that supply power to the motor of the eccentric press, there is only FPSC programmable controller for safety protection. In this solution, the wiring cost required for the connection of input and output cables is omitted, and the control function of the logic control circuit is set to be the same as the original relay protection control by software. In order to make the transformation of old equipment easier and faster, and reduce the price, Fiessler also provides software and hardware solutions (safety protection SPS and safety protection photoelectric control cabinet) matching different types of presses

in the "mechanical press safety protection software package", all positions of the mechanical press requiring safety monitoring are monitored with FPSC safety protection SPS (programmable control system). The function monitoring of the press, such as stamping stroke monitoring, crankshaft fracture monitoring, stroke switch monitoring, adjustment of working mode, one-way stamping, automatic stamping, emergency stop, two hand operation and foot switch monitoring, are all in the charge of the ready-made t ü V certified software package. In addition, takt Makro beat macro (1~4 beats) is available for selection and use

improve production capacity

the production capacity of the monitored press can be significantly improved by using the safety protection program module in combination with the photoelectric control cabinet. When two beats are selected, the operator can take the stamped workpiece out of the press and put the workpiece to be stamped into the press. After going in and out of the photoelectric control cabinet twice, the electrical control system can control the eccentric press to complete a centrifugal constant acceleration experiment without sending instructions again; Rocking test; Secondary stamping. This operation mode obviously improves the production capacity of the press, and also improves the ergonomic conditions of the press operation. During the return journey of crankshaft rising, if a part of the operator enters the safety protection area of the photoelectric control cabinet, the control system will immediately control the press to stop working, so as to avoid the injury caused by the machine to the human body

in addition, this technically certified software module can also provide many logic control functions, such as "and", "and not", "or", "or not", timers and counters, so that programmers can easily write programs

the fhmi interface circuit board of human machine tool company can realize the visualization of different stamping programs. It can be simply and conveniently connected with the existing RS 232 interface, thus providing the operator of the eccentric press with the possibility to display the selected program and connection status information

with the fhmi interface circuit board of human machine tool company, the visualization of different stamping programs can be realized.

another improvement measure that conforms to the ergonomic principle and is conducive to improving the production capacity of the press is to monitor the distance between the human body and the danger zone. This safety distance should be as small as possible, but its size mainly depends on the reaction speed of the control system and sensors

not only the ulct photoelectric control cabinet, but also the FPSC programmable control system used has extremely fast response speed. These two systems provide maximum security because they are developed according to the latest technical standards and have passed the inspection and certification of t ü v. In the stamping process control program, perfomance level (PL) program conforming to en 13849 standard and safety integration level (SIL) program conforming to en 61508 standard are used

Figure 4 after completing the technical transformation of the press, the surface of the press was repainted to make it look almost the same as the new machine tool.

after completing the technical transformation of the eccentric press, the surface of the press was repainted to make it look almost the same as the new machine tool

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