JP2022094856A - Breakthrough shock absorber of press machine - Google Patents

Abstract

To provide a breakthrough shock absorber that performs breakthrough shock absorption without performing piston adjustments on a breakthrough shock absorbing hydraulic cylinder each time a metal mold is replaced nor slide position detection on breakthrough occurrence, and is free of reaction to a slide after the breakthrough shock absorption and a rise in oil temperature due to continuous operation.SOLUTION: (1) A hydraulic shock absorbing cylinder is employed as a hydraulic balance cylinder supporting a slide from below, and adapted to a breakthrough at any position of a slide stroke. (2) A strain quantity of a press frame is measured, an occurrence period of the breakthrough is detected from the strain quantity, and a shock absorber is placed in operation. (3) A hydraulic flow and a flow rate are controlled with a check valve such as an electromagnetic type flow rate control valve to suppress a reaction to the slide. (4) The pressure oil of the hydraulic balance cylinder is transmitted to a pneumatic/hydraulic pressure booster to absorb breakthrough energy on an air pressure side.SELECTED DRAWING: Figure 1

Description

The present invention relates to a breakthrough shock absorber that absorbs and relaxes impact vibration due to breakthrough that occurs when punching is performed with a press machine.

There is a proposal of Japanese Patent Application Laid-Open No. 10-58200 as an example of the prior art using hydraulic pressure in order to reduce the impact vibration due to the breakthrough that occurs when punching with a press machine.
A buffer hydraulic cylinder is provided on the bolster side, and the height of the piston inside the buffer hydraulic cylinder is adjusted so that the slide pushes and pressurizes the piston of the buffer hydraulic cylinder only during punching to absorb and relax breakthrough energy with hydraulic pressure. It is a type that adjusts to an appropriate position and sends the generated hydraulic pressure to an accumulator like an air / hydraulic converter to absorb breakthrough energy.

As a method that does not require adjusting the piston height of the buffer hydraulic cylinder, a shock absorber hydraulic cylinder having a stroke length equivalent to the slide stroke is provided on the bolster side, the buffer piston is attached to the slide side, and the slide stroke. JP-A-2004 is an example of a format that absorbs breakthrough energy by discharging the hydraulic pressure in the buffer hydraulic cylinder through a throttle valve, relief valve, etc., only when a breakthrough occurs. There is a proposal of Japanese Patent Publication No. -237341.

As an example of a format that attempts to absorb breakthrough energy by still compressing compressed gas or the like instead of hydraulic pressure (hydraulic pressure), Japanese Patent Application Laid-Open No. 09-253898 (Patent 379292) is proposed above. Immediately before the mold comes into contact with the material blank, the device is adjusted to operate, and the punching process is advanced while still compressing the compressed gas, and when the reaction force becomes the maximum, breakthrough can be dealt with. The timing is adjusted so as to.

Japanese Unexamined Patent Publication No. 10-058200 Japanese Unexamined Patent Publication No. 2004-237341 Japanese Patent Application Laid-Open No. 09-253898 (Patent No. 3792292)

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However, in the proposal of Japanese Patent Application Laid-Open No. 10-05800, in order to adjust the height position of the buffer piston in the buffer hydraulic cylinder, a hydraulic plunger pump with a constant discharge amount for ascending and descending is provided, and when ascending, respectively. It is a mechanism that operates separately when descending and moves the buffer piston up and down according to the operating amount of each plunger pump, but when driving multiple hydraulic jacks at low pressure, each hydraulic jack Even if there is a variation in the spring constant of the return spring or a slight difference in the packing resistance, the operation starts from the one with the smaller resistance value, so it is not possible to operate in synchronization all at once, and the height of the cushioning piston is uniform during the stroke. It is difficult to align with the above, and even when descending as well as when ascending, it operates from the one with the smaller resistance value such as the strength of the return spring and the difference in packing resistance and pipeline resistance. , The position of the return cushioning piston is also irregular and does not have a uniform height.

In the proposal of JP-A-2004-237341, the inside of the buffer hydraulic cylinder when the buffer (piston) ram is pulled up by the pulling force of the articulated slide without having a hydraulic source for operating the buffer (piston) ram. Since the mechanism is such that the hydraulic oil of the oil tank is sucked into the buffer hydraulic cylinder through the pilot check valve with the negative pressure generated in, if a suction failure occurs during high-speed operation, it will be in a vacuum state and the buffer hydraulic cylinder will be in a vacuum state. Since the hydraulic oil shortage will occur inside and cause the buffer (piston) ram to perform an air thrust operation, it is necessary to ensure that the hydraulic oil can sufficiently flow into the buffer hydraulic cylinder in conjunction with the slide. When a breakthrough occurs, the pilot check valve is closed by the signal from the detector, and the high-pressure oil generated in the buffer hydraulic cylinder by the breakthrough energy is released to the oil tank through the flow control valve and the relief valve. Although it absorbs energy, it discharges pressure oil through a throttle valve, relief valve, etc. Therefore, in continuous operation such as continuous punching, the oil temperature rises due to the flow friction of the pressure oil.

In the mechanism proposed in JP-A-09-253898 (Patent 379292), after the breakthrough is completed, the repulsive force of the compressed gas strongly pushes up the slide that returns upward, and urethane rubber, a spring, or the like is used as a stripper. It is thought that it will act as a repulsive force and cause a two-step raised state with respect to the slide, as in the case of the case, and in any case, it is necessary to adjust the operating position before work. It is the same as the one proposed in the previous term.
In view of the above-mentioned conventional drawbacks, in order to absorb breakthrough energy by hydraulic pressure, the height of the buffer piston of the buffer hydraulic cylinder is not adjusted every time the mold is replaced, and when breakthrough occurs. There is no need to adjust the position of the detector to check the slide position, and the shock absorber that stores breakthrough energy after the breakthrough does not push up the slide and cause a two-step raising state. It is an object of the present invention to provide a breakthrough shock absorber and a control method thereof that suppresses an increase in oil temperature due to continuous punching and alleviates vibration noise of a press machine during punching.

In order to achieve the above object, the invention according to claim 1 is a type in which a hydraulic balance cylinder that supports the slide of a press machine is provided on the bed side and the slide is supported from the bottom upward, and the conventional balance cylinder uses only pneumatic pressure. Although it has been operated, it is a mechanism that can always follow the movement of the slide by operating the hydraulic balance cylinder with the hydraulic pressure converted from air pressure to hydraulic pressure by an air / hydraulic converter or an air / hydraulic booster. ..
The breakthrough phenomenon of the press machine occurs when the strain energy due to the elastic deformation of the press frame due to the load is released at once due to the breakage of the material. Instead of detecting from the position etc., measure the amount of strain of the press frame due to the load with a strain gauge etc. attached to the press frame, and based on that value, use an electromagnetic proportional flow control valve etc. with a variable shockless function. , The hydraulic balance cylinder is operated. Just before the material breaks, the hydraulic pressure in the hydraulic balance cylinder is fixed by an electromagnetic proportional flow control valve, etc., and the movement of the descending slide is damped by the hydraulic pressure of the hydraulic balance cylinder. By the breakthrough energy, the high pressure oil generated in the hydraulic balance cylinder is made to flow into the hydraulic side of the separately provided high pressure air / hydraulic booster to absorb the breakthrough energy. ..
The absorption of breakthrough energy is received on the pneumatic side of the air / hydraulic booster for high pressure, and the hydraulic side only propagates the breakthrough energy from the hydraulic balance cylinder to the hydraulic side of the air / hydraulic booster for high pressure. Therefore, the oil temperature does not rise due to the leakage of pressure oil from the relief valve or the like, and since the hydraulic balance cylinder is used as the buffer cylinder of the shock absorber, it is within the slide stroke range of the press machine. However, it can be performed anywhere, and it is not necessary to adjust the operating position of the buffer hydraulic cylinder or the like every time the mold is changed.

According to the second aspect of the present invention, a check valve is provided in the circuit from the hydraulic balance cylinder to the hydraulic side of the empty / hydraulic booster for high pressure, and when a breakthrough occurs, the hydraulic pressure of the hydraulic balance cylinder is increased by an electromagnetic proportional flow control valve or the like. When the circuit is closed, the high-pressure oil generated in the hydraulic balance cylinder flows into the hydraulic side of the empty / hydraulic booster for high pressure through the check valve, and the return is blocked by the check valve, so high pressure Even if high-pressure oil is stored as pressure energy on the hydraulic side of the empty / hydraulic booster, the high-pressure oil flows into the low-pressure hydraulic circuit of the hydraulic balance cylinder after breakthrough buffering, like urethane rubber or springs. The switching timing and flow pressure are adjusted by an electromagnetic proportional flow control valve that has a shockless function so that repulsive force does not act on the slide, and the high pressure oil in the empty / hydraulic booster for high pressure is hydraulic pressure during rising operation. The surge pressure is erased and returned to the hydraulic circuit of the balance cylinder without shock, and the slide during the ascending stroke is pushed up by the surge pressure so that it does not cause a two-step raising state. Is.

In the invention of claim 3, in the punching process, the punching process starts from the point where the punch comes into contact with the material, the partial compression of the processed material starts between the punch and the die, and if the processing further progresses, the punch and the die When it bites into the processed material and exceeds the fracture strength of the material due to wedge action, cracks occur from the corners of the punch and die, and when each crack progresses and is connected, it is a fracture, but the beginning of cracking is the load. The punching load peaks at the time of crack occurrence, and gradually drops at the initial stage of cracking as the crack progresses, and then drops sharply after the middle stage. The electrical signal from the strain gauge shown also shows such a value, and the electronic circuit of the setter that gives a command signal to the power amplifier that controls the electromagnetic proportional flow control valve that operates the hydraulic balance cylinder is cracked. If the electromagnetic proportional flow control valve is set to start flow adjustment based on the electrical signal of the strain gauge when the load starts to decrease immediately after the pressure peak, the strain of the press frame for each punching process is distorted. Since the electromagnetic proportional flow control valve can be operated by detecting the break time of the material from the maximum value of the amount, no matter how the mold changes and the break position of the material changes, the slide at the time of breakthrough occurs. However, regardless of the position, the hydraulic circuit of the hydraulic balance cylinder can be closed anywhere within the slide stroke range to accommodate breakthrough, and even if the mold is the same, the material of the material can be used. There are some differences in the amount of pressurization and the fracture time due to variations and other conditions, and the breakthrough occurrence time cannot be fixed, but the electrical signal of the strain gauge is used for each press cycle. Since it operates by detecting the break time, it is possible to respond to this change.
If the operation of the electromagnetic proportional flow control valve, etc. is started based on the peak break of the material, the slide pushes both the machined material and the hydraulic balance cylinder to push the break while adjusting the flow rate of the hydraulic circuit of the hydraulic balance cylinder. At this time, the repulsive thrust against the slide from the processed material, which is in the state of progress of cracking, becomes smaller, and the amount of hydraulic oil discharged in the hydraulic balance cylinder by the electromagnetic proportional flow control valve etc. By adjusting, the hydraulic pressure in the hydraulic balance cylinder does not rise immediately, and the descent of the slide cannot be fixed immediately. Although the work material is pushed through and the breakage is completed, the electromagnetic proportional flow control valve, etc. is used to counteract the progress of cracking and the decrease in the repulsive thrust from the work material to the slide. As the flow rate adjustment progresses and the hydraulic pressure in the hydraulic balance cylinder rises, the hydraulic balance cylinder takes over the thrust of the slide instead of the machined material, and the press frame was distorted by the load after breaking. The hydraulic pressure of the hydraulic balance cylinder receives the protruding energy of the slide due to the breakthrough phenomenon that occurs when the strain shrinks at once, and the strain gauge fluctuates according to the progress from the start to the end of the fracture of the processed material. By adjusting the flow rate with an electromagnetic proportional flow control valve, etc., according to the electrical signal of, the switching work to receive the repulsive thrust received from the processed material by the hydraulic pressure of the hydraulic balance cylinder can be performed continuously without pulsation. Yes, even if there are fluctuations in the breaking state due to variations in the material and other conditions, it is possible to deal with vibration noise of piping and press machines without causing an oil hammer phenomenon in the hydraulic balance cylinder. It can be reduced.

In the present invention, the method of receiving the breakthrough energy of the press machine by hydraulic pressure at the time of punching is always prepared by the hydraulic pressure of the hydraulic balance cylinder that supports the slide from the bottom upward, and the hydraulic pressure is applied every time the die is replaced. Since it is no longer necessary to deploy and adjust the jack, the breakthrough occurrence time is not detected from the positional relationship of the crank shaft and slide, but is performed based on the amount of strain of the press frame due to the load using a strain gauge or the like. The work of adjusting the position of the breakthrough detector according to the mold shape dimensions and the like is eliminated, and the mold replacement work can be performed simply.

Since the pressure oil of the hydraulic system is controlled using an air / hydraulic booster, etc., it can be operated on the factory airline without the need for a hydraulic pump unit, etc., and the hydraulic pressure is controlled on the pneumatic side. At the same time, by absorbing breakthrough energy on the pneumatic side, it is possible to suppress the rise in oil temperature and enable continuous operation. Since the flow of pressure oil is controlled, the pressure oil can flow into the hydraulic side of the empty / hydraulic booster for high pressure without causing an oil hammer phenomenon in the hydraulic balance cylinder when a breakthrough occurs. Conversely, when returning high-pressure oil from an empty / hydraulic booster for high pressure to the hydraulic balance cylinder side, the check valve prevents backflow, and the electromagnetic proportional flow control valve or the like squeezes the high-pressure oil into the hydraulic circuit. Since shockless switching control can be performed without generating surge pressure, there is no need to push up the slide strongly to cause a two-step raising state as in the case of using urethane rubber, springs, etc. and compressed gas. Not only can the vibration noise of breakthrough be buffered, but also the press machine can be made to perform a smooth press operation.

Even if the punching and shearing process is the same, the load and breaking time will change as the wear of the mold and the quality of the material change, but even if the mold and the processed material change, the punching and shearing load curve is omitted. It draws a similar curve, and when the load starts to decrease immediately after the load peak, it is controlled as the start of operation of the electromagnetic proportional flow control valve, etc., so it is detected from the strain gauge for each machining. Based on the peak load and the electric signal of the load fluctuation, the change of the mold state and the material is regarded as the change of the load, and the electromagnetic proportional flow control valve etc. is operated each time. Breakthrough control can be performed for each stroke regardless of the state of By operating the electromagnetic proportional flow control valve, etc. based on the electrical signal of the strain gauge during breakthrough to adjust the operation start time and flow rate, the hydraulic balance is adjusted from the machined material when breakthrough occurs. Since the load can be transferred smoothly to the cylinder and the operating time is widened, it is possible to deal with slight fluctuations in the breaking time due to variations in the quality of the processed material. The operation corresponding to breakthrough can be automatically controlled based on the electric signal of the strain gauge for each machining stroke.

It is an operation system diagram of this invention.

As shown in FIG. 1, hydraulic balance cylinders 11a and 11b are provided on the bed 9 side of a press machine for punching (crank press, etc.), and a hydraulic balance cylinder is attached to a slide 7 that slides by rotation of the crankshaft 1. The basic embodiment is a structure in which the piston rods 10a and 10b of 11a and 11b are connected to each other and the slide 7 is supported upward from the bed 9 side.

The hydraulic pressure in the hydraulic balance cylinders 11a and 11b is conducted to the air / hydraulic booster 33 for low pressure and the air / hydraulic booster 16 for high pressure through the electromagnetic proportional flow control valve 14 having a variable shockless function, and the slide 7 The pressure oil in the hydraulic balance cylinders 11a and 11b repeatedly flows in and out of the low-pressure air / hydraulic booster 33 due to the piston rods 10a and 10b linked to the movement of the hydraulic balance cylinders 11a and 11b.

Hydraulic balance cylinders 11a and 11b are hydraulically balanced cylinders 11a and 11b in order to reduce the amount of oil flowing in and out of the hydraulic balance cylinders 11a and 11b, to reduce the size of piping functional parts, and to deploy the hydraulic balance cylinders 11a and 11b in the limited space on the bed 9 side. 11a and 11b use small diameter cylinders, and in order to balance the weight with the slide 7 and the mold, the pressure is increased by the air / hydraulic booster 33 for low pressure, and the hydraulic balance cylinders 11a and 11b have a higher pressure than the air pressure. It supplies hydraulic pressure.

During normal press operation, the solenoid 13 of the electromagnetic proportional direction / flow control valve 14 is energized, but the amount of strain of the press frame due to pressurization is attached to the press frame (not shown) during punching down. The change in the pressing force during the punching process is measured by the electric signal from the strain gauge 8, and when the pressing force starts to decrease immediately after the peak of the pressing force, the excitation of the solenoid 13 is turned off as the start of breakage of the material. The electromagnetic proportional flow control valve 14 cuts off the hydraulic circuit between the hydraulic balance cylinders 11a and 11b and the empty / hydraulic booster 33 for low pressure to fix the hydraulic pressure in the hydraulic balance cylinders 11a and 11b, so that the slide is descending. Although the brake is applied to the movement of 7, the electromagnetic proportional flow control valve 14 can adjust the flow rate by adjusting the switching timing with an electric signal, so instead of applying the brake immediately, the material is applied from the peak pressure. The change in the progress state of the breakup is measured by the strain gauge 8, and as the breakage progresses, the counter-push force from the machined material becomes smaller and the electromagnetic proportional flow control valve 14 is set to be inversely proportional to the decrease in the pressing force. Operate in the closing direction to increase the pressure in the hydraulic balance cylinders 11a and 11b, and when the processed material breaks, the hydraulic pressure in the hydraulic balance cylinders 11a and 11b replaces the processed material, and the repulsive thrust of the slide 7. It is in charge of dealing with the breakthrough phenomenon after breakage.

When the electromagnetic proportional flow control valve 14 is closed to support breakthrough, the high pressure oil that is suddenly generated inside the hydraulic balance cylinders 11a and 11b due to the breakthrough energy is discharged by the check valve 12 for low pressure. While preventing backflow to the booster 33, it flows into the air / hydraulic booster 16 for high pressure through the check valve 15 and pushes up the piston 17 to push the compressed air on the pneumatic side back to the auxiliary air tank 19. , The energy of the pressure on the hydraulic side is converted into air pressure, the energy of the pressure is released to the pneumatic side to absorb the breakthrough energy, and the pressure is adjusted by the air pressure reducing valve 22 on the pneumatic side. There are no pressure adjustment function parts such as relief valves on the hydraulic side, and some throttle valve elements occur during the switching transition period of the electromagnetic proportional flow control valve 14, but the release of pressure energy is the empty / hydraulic booster 16 for high pressure. Since it is performed on the pneumatic side through the hydraulic system, when the pressure oil propagating the pressure flows in and out, the fluid friction resistance in the hydraulic system becomes an element that raises the oil temperature in the hydraulic system. Since the amount of oil discharged from the hydraulic balance cylinders 11a and 11b to the air / hydraulic booster 16 for high pressure due to the breakthrough is a substantially constant small amount, the heat generation capacity is small and the oil temperature rises. It can be suppressed and can be used for continuous operation.

The end of the breakthrough state (the end of punching) is set by the rotary encoder 3 (the rotary encoder is used, but the limit switch and proximity switch for detecting the top dead point and bottom dead point, which are attached to conventional crank presses, etc.). Detecting that the crank shaft 1 is near the bottom dead point, the solenoid 13 is excited to use the electromagnetic proportional flow control valve 14, the hydraulic balance cylinders 11a and 11b, and the empty / hydraulic boosters 16 and 33. When the hydraulic circuit is conducted, the high-pressure oil on the hydraulic side of the high-pressure air / hydraulic booster 16 flows back into the hydraulic circuit of the hydraulic balance cylinders 11a and 11b and the low-pressure air / hydraulic booster 33, resulting in low pressure. Push back the piston 34 of the air / hydraulic booster 33 for hydraulic pressure, and the pressure inside the hydraulic circuit drops to the pressure on the hydraulic side of the air / hydraulic booster 33 for low pressure to return the hydraulic balance cylinders 11a and 11b to the normal operating state. In preparation for the press operation of the above, the high pressure oil of the air / hydraulic booster 16 for high pressure rapidly flows into the hydraulic circuit of the air / hydraulic booster 33 for low pressure, and surge pressure is generated to generate oil. The electromagnetic proportional flow control valve 14 controls the inflow speed by adjusting the switching speed and the flow rate even when switching to the return stroke so as not to cause a hammer phenomenon.

Even if the timing of switching to the return stroke is delayed and the hydraulic circuit is closed by the electromagnetic proportional flow control valve 14 and the slide 7 goes up, the high pressure oil of the empty / hydraulic booster 16 for high pressure Is stopped from flowing into the hydraulic circuit by the check valve 15, and the low pressure oil of the empty / hydraulic booster 33 for low pressure flows into the hydraulic circuit to the hydraulic balance cylinders 11a and 11b through the check valve 12. Therefore, the hydraulic balance cylinders 11a and 11b can operate ascending as usual, and even if breakthrough energy is stored as pressure energy on the hydraulic side of the empty / hydraulic booster 16 for high pressure, urethane rubber It does not act as a repulsive force on the slide 7 after the end of descent, unlike the spring and hydraulic pressure method, and it does not act as a repulsive force at any position during the ascending stroke of the slide 7, even after stopping at the upper end of the ascending stroke. The solenoid 13 is excited and the electromagnetic proportional flow control valve 14 can perform a shockless return switching operation. In the proximity switch 18, the piston 17 in the air / hydraulic booster 16 for high pressure is the high pressure oil inside. This is to confirm that the oil pressure has returned to the lowermost end by releasing the entire amount.

If the amount of oil in the hydraulic circuits of the hydraulic balance cylinders 11a and 11b and the air / hydraulic boosters 16 and 33 decreases and the operating position of the piston 34 in the air / hydraulic booster 33 for low pressure is lowered, the proximity is reached. The position of the piston 34 is detected by the switch 35, the solenoid 29 of the air electromagnetic valve 28 is excited, the hydraulic pump 25 driven by pneumatic pressure is operated, and a certain amount of hydraulic oil is replenished in the hydraulic circuit. However, it is not only for replenishing the hydraulic oil, but also for circulating the hydraulic oil in the hydraulic circuit to the oil tank 7 and replacing it. The crank shaft 1 is stopped at the bottom dead point, and the adjustment bolt is used. In step 6, the ram rods 10a and 10b of the hydraulic balance cylinders 11a and 11b connected to the slide 7 are lowered to the lowermost end, and the pressure oil of the pneumatically driven hydraulic pump 25 is used to reduce the pressure of the hydraulic pressure booster 33. If the pressure oil 34 is pushed up to the uppermost end and the pressure oil is still sent, the excess pressure oil returns from the relief valve 36 to the oil tank 27, so that the hydraulic oil in the low pressure empty / hydraulic booster 33 is replaced. The relief valve 36 is set to a height higher than the normal operating pressure as a safety valve and does not normally operate. The hydraulic oil in the hydraulic circuit is circulated to the oil tank 27 for regular operation. Even if the oil temperature of the hydraulic oil inside the closed hydraulic circuit rises slightly due to continuous operation, the hydraulic oil can be circulated and replaced regularly. It is possible to suppress deterioration of hydraulic oil in the hydraulic circuit and increase in oil temperature.

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As a means of knowing how much strain and stress are generated in the press frame due to the press load, a method of attaching a strain gauge to the press frame and measuring is a known technique that has been conventionally performed. On the contrary, it is also a technique that has been used as a method to know the pressurization amount as the numerical value of the strain gauge at that time, and it is commercialized as a load cell. This device is operated by measuring the load of the press machine, but as measurement and command measures to operate this device, (1) strain gauge to detect the load, (2) signal from strain gauge If there is an arithmetic device for proper processing and (3) an amplifier for amplifying the signal from the arithmetic device, this device can be operated, but is it operating with the correct load value as it is? Is unknown, and (4) a display device for outputting the result processed by the arithmetic device is required, but the output of the strain gauge with respect to the pressurizing load differs greatly depending on the press machine, so the press pressurization amount and load The display does not match. Therefore, by pressurizing the load cell with the slide 7 using the load cell, the sensitivity is adjusted so that the display load value of the load cell and the display load value of the device match. As a result, the press machine itself has been calibrated as a load cell, and in addition to knowing the pressurized load not only as a measurement / command device for breakthrough shock absorbers but also as a press load gauge, it is possible to grasp the state of the mold and detect abnormalities. As a load monitoring device, it can also be applied to mold management.

Although the hydraulic balance cylinders 11a and 11b are used, they always follow the movement of the slide 7 by using a small-diameter hydraulic cylinder driven by the hydraulic pressure of the low-pressure air / hydraulic booster 33 operated in the factory airline. Since it has such a configuration, it can be attached to the bolster side of the existing press machine as a hydraulic shock absorber so that it operates following the movement of the slide, and it can be used as a retrofit breakthrough shock absorber, and it is already distorted. If the press machine is equipped with a load gauge using a gauge, the load gauge device can be used for retrofitting work.

1 Crank shaft 2 Conrod 3 Rotary encoder 4 Plunger 5 pin 6 Adjustment bolt 7 Slide 8 Strain gauge 9 Bed 10a, 10b Piston rod 11a, 11b Hydraulic balance cylinder 12, 15, 24 Check valve 13, 29 Electromagnetic proportional flow rate Control valve 16 Air / hydraulic booster for high pressure 33 Air / hydraulic booster for low pressure 17,34 Piston 19,37 Auxiliary air tank 20,38 Stop valve 21,30,39 Pressure gauge 22,31,40 Air pressure reducing valve 23, 32,41 Air filter 25 Pneumatically driven hydraulic pump 26 Strainer 27 Oil tank 28 Air electromagnetic valve 18,35 Proximity switch 36 Relief valve

Claims (3)

The hydraulic balance cylinder that supports the slide of the press machine from the bottom upward is operated by an air / hydraulic converter or an air / hydraulic booster, and the strain amount of the press frame during punching is measured to detect the break time of the material. Then, operate the hydraulic balance cylinder with an electromagnetic control valve, etc., and use the hydraulic balance cylinder as a hydraulic buffer cylinder to receive breakthrough energy and use the high-pressure oil generated in the hydraulic balance cylinder for high pressure separately. Breakthrough shock absorber that absorbs and relaxes shock vibration by breakthrough energy by discharging to the hydraulic side of the air / hydraulic booster and compressing the pneumatic side. The high-pressure oil in the hydraulic balance cylinder generated by the breakthrough energy flows into the hydraulic side of the high-pressure air / hydraulic booster through the check valve, and the high-pressure oil in the high-pressure air / hydraulic booster after the breakthrough ends. However, the check valve stops the backflow to the hydraulic balance cylinder, and while adjusting the flow rate of the high-pressure oil in the empty / hydraulic booster for high pressure, it returns to the hydraulic balance cylinder circuit without shock, and rises after processing. The breakthrough shock absorber according to claim 1, wherein the press machine can be operated without causing the slide in the process to be raised by two steps. The fracture time is detected based on the strain amount of the press frame due to the load for each punching process, and the switching timing of the electromagnetic control valve, etc. is determined based on the strain amount of the press frame that changes according to the progress of the break. A claim that adjusts the flow rate so that the hydraulic balance cylinder can absorb and relax breakthrough energy while adjusting the internal pressure of the hydraulic balance cylinder so that the hydraulic balance cylinder can take charge of the press load instead of the repulsive thrust from the machined material at the time of breakage. Item 1. Breakthrough shock absorber according to Item 1.

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