JPH0726014Y2 - Air pressure regulator for multiple air cylinders - Google Patents

Description

[Detailed Description of the Invention] [Industrial application] The present invention relates to a device for adjusting the air pressure of a plurality of air cylinders, and relates to the air pressure of a die cushion air cylinder or a knockout air cylinder of a press machine. It is available for adjustment.

[Conventional technology]

The transfer press machine is equipped with a die cushion for each processing stage, and the air pressure of the air cylinder and tank of this die cushion acts on the molded product during drawing to prevent wrinkles from forming on the molded product. To do. The air pressure of the air cylinder and tank of each die cushion is determined according to the press-molded product.Therefore, when the moving bolster moves to the mold change position outside the transfer press machine to perform the mold change, the air cylinder and tank are The air pressure must be adjusted to that applied to the next molded product.

FIG. 4 shows an air pressure adjusting device for a conventional die cushion air cylinder provided by the present applicant as Japanese Utility Model Laid-Open No. 57-11625.

The die cushions A and B have switching valves 72 for each air cylinder 71A and 71B.
Tanks 73A and 73B are provided with A and 72B interposed,
The tanks 73A and 73B are connected to the air supply circuit 76 via the check valves 74A and 74B and the air supply valves 75A and 75B, and the exhaust circuit 79 through the check valves 77A and 77B and the exhaust valves 78A and 78B. , Air supply circuit 76 and exhaust circuit 79
Are connected and disconnected by a connecting valve 80. Further, an air source is connected to the air supply circuit 76 via a shutoff valve 81. The right ends of the air supply circuit 76 and the exhaust circuit 79 in FIG. 4 are closed ends.

The tanks 73A, 73B are provided with pressure detection / comparison devices 82A, 82B, and these devices 82A, 82B have ports 83A, 83B for receiving the air pressure of the tanks 73A, 73B and air sources adjusted by regulators 84A, 84B. The ports 85A and 85B for receiving the air pressure from the device are provided, and the piston rods 86A and 86B that receive the spring force of the devices 82A and 82B correspond to the magnitude of the air pressure from the ports 83A, 83B, 85A and 85B. Move and limit switch 87A, 87B, 88
Activate A, 88B. Limit switches 87A and 87B are air supply valves
Limit switch 88A, 88B connected to 75A, 75B, exhaust valve
Connected to 78A, 78B.

After the drawing work is completed, move the moving bolster to the mold replacement position, and at this position lower the air pressure of the tank 73A that was currently high pressure and lower the air pressure of the tank 73B that was low pressure corresponding to the next molded product. When increasing the pressure, switch valve 7
2A and 72B are switched to positions 72Aa and 72Ba, and shutoff valve 81 is switched to position 81a to bring them into a shutoff state, and connecting valve 80 is switched to position 80a to bring air supply circuit 76 and exhaust circuit 79 into communication. If the set pressure of regulator 84A is reduced, port 8
Since the air pressure entering the device 82A from 5A decreases, the movement of the piston rod 86A actuates the limit switch 88A to switch the exhaust valve 78A to the position 78Aa, and increasing the set pressure of the regulator 84B increases the device from the port 85B.
Since the air pressure entering the 82B increases, the piston rod 8
6B movement causes limit switch 87B to operate and supply valve 7
5B is switched to the position 75Ba, and as a result, the high pressure air in the tank 73A is supplied by the air in the air supply circuit 76 to the air supply valve 75B and the check valve 7B.
As it flows into the tank 73B via 4B, the check valve 77A,
Exhaust valve 78A, exhaust circuit 79, connection valve 80, air supply circuit 76, air supply valve 75B, and check valve 74B flow into tank 73B and tank 7
The air pressure of 3A and 73B changes so as to be the same.

After the air pressure in tanks 73A and 73B becomes the same, connect valve 80
Is switched to the position 80b, and thereafter, if the air pressure in the tank 73A is still higher than the next set pressure, the air in the tank 73A is discharged from the connecting valve 80 in the exhaust circuit 79, and the tank 73B
If the air pressure is lower than the next set pressure, the shutoff valve 81 is switched to the position 81b to supply the air from the air source to the tank 73B via the air supply circuit 76 and the like. As a result, the air pressure in the tanks 73A, 73B becomes the set pressure, and the switching valves 72A, 72B
To position 72Ab, 72Bb, air cylinders 71A, 71B
The air pressure of is the same as the set pressure.

According to the above, since the air pressure is adjusted by supplying air from the high pressure tank to the low pressure tank, it is possible to reduce the amount of air compressed from the atmosphere and supplied to the tank and the amount of air discharged from the tank to the atmosphere. Energy can be achieved.

[Problems to be solved by the device]

However, according to the above conventional technique, as described above, the connecting valve 80
With the tanks 73A and 73B in communication with each other, when the air in the tank 73A is flowing into the tank 73B, if the air pressure difference between the tanks 73A and 73B becomes small, the amount of air flowing into the tank 73B gradually decreases. As a result, there is a problem that it takes a long time until the air pressures in the tanks 73A and 73B reach the same pressure, and the air pressure adjustment time becomes long.

In addition to the above, the switching time of the connecting valve 80 is uniformly set by a timer, and after this, the connecting valve 80 is switched to the position 80b after a certain period of time and the air pressure of the tanks 73A and 73B is transferred to the tank 73B before reaching the same pressure. It is also possible to stop the inflow of air, but according to this, since the air pressure of the tanks 73A, 73B is various depending on the molded product,
Depending on the air pressure, before the air is sufficiently supplied to the tank 73B or after the air pressures of the tanks 73A and 73B become the same pressure, the setting time of the timer is reached and the connection valve 80 is switched. In some cases, if the set time is reached before sufficient air is supplied to the tank 73B, energy saving cannot be substantially realized.
When the set time is reached after the air pressures of 73A and 73B become the same, it is practically impossible to shorten the air pressure adjustment time.

An object of the present invention is to provide an air pressure adjusting device for a plurality of air cylinders that can achieve both energy saving and shortening of the air pressure adjusting time.

[Means for Solving the Problems]

Therefore, the air pressure adjusting device for a plurality of air cylinders according to the present invention is provided with a tank for each air cylinder,
An air supply circuit and an exhaust circuit are connected to these tanks via an air supply / exhaust valve, and the air supply circuit and the exhaust circuit are connected and disconnected by a connecting valve, and the air supply circuit is connected via a cutoff valve. In an air pressure adjusting device for a plurality of air cylinders connected to an air source, a control device is connected to the air supply / exhaust valve, and the air supply circuit and the exhaust circuit of the air supply circuit when a plurality of tanks are connected to the control device are connected. Via the pipe air pressure calculation unit that calculates the pipe air pressure from the original tank air pressure and the tank capacity, and the air supply circuit and the exhaust circuit that are connected by the connection valve by switching the air supply and exhaust valve. Air is supplied from the high-pressure tank to the low-pressure tank, and when the air pressure in the tank reaches a predetermined value with respect to the pipeline air pressure, the air supply to the low-pressure tank is stopped based on the tank air pressure signal. Valve switching drive And parts, is characterized in that the provided.

[Action]

When changing the air pressure of the air cylinder to the next set pressure, the valve switching drive of the control unit switches the air supply / exhaust valve, which causes the exhaust circuit and the air supply circuit connected by the connecting valve to communicate. Air is supplied from the high-pressure tank to the low-pressure tank.The air is supplied from the tank air pressure and the tank capacity, which is calculated by the pipeline air pressure calculator. When a predetermined value is reached for the road air pressure (air pressure when the tanks have the same pressure), the valve switching drive unit supplies and exhausts air based on the tank air pressure signal that detected this predetermined value. It is stopped by switching the valve.

After this, air supply and air discharge for correcting the excess and shortage air pressure is performed for each tank, and the air pressure of each tank is set to the set pressure.

As described above, in the present invention, the supply of air to the low-pressure tank is stopped without waiting for the air pressures of the tanks to become the same, and this supply stop is based on the air pressure detection signal of the tank. Therefore, even if the original air pressure of the tank is any, it is possible to save energy and shorten the air pressure adjusting time for each air pressure.

〔Example〕

FIG. 1 is an air circuit diagram of an apparatus according to an embodiment of the present invention, and FIG. 2 is a control block diagram thereof. The apparatus of this embodiment is applied to three die cushions A, B and C of a transfer press machine.

As shown in Fig. 1, air cylinders 1A, 1B and 1C have switching valves 2A, 2B and 2C.
Tanks 3A, 3B, 3C are connected via
Air supply / exhaust valves 4A, 4B, 4C are connected to A, 3B, 3C. In this embodiment, the intake / exhaust valves 4A, 4B, 4C are 4-port 3-position switching valves,
It has 4Aa, 4Ba, 4Ca, positions 4Ab, 4Bb, 4Cb, and positions 4Ac, 4Bc, 4Cc. These supply / exhaust valves may be composed of two valves, an intake valve and an exhaust valve, as in the conventional device shown in FIG.

When a transfer press machine draws a molded product, the switching valves 2A, 2B, 2C are set to the positions 2Aa, 2Ba, 2Ca, and the supply / exhaust valve 4A,
4B, 4C are switched to positions 4Ab, 4Bb, 4Cb respectively, and by the air pressure in the tanks 3A, 3B, 3C and the air cylinders 1A, 1B, 1C acting on the molded product via a cushion pin etc. not shown, Wrinkling of the molded product is prevented.

The supply / exhaust valves 4A, 4B, 4C are connected to an air supply circuit 6 via check valves 5A, 5B, 5C and an exhaust circuit 8 via check valves 7A, 7B, 7C to supply these air. The circuit 6 and the exhaust circuit 8 are connected and disconnected by a connecting valve 9 so that they can be shut off. The connecting valve 9 also serves as a valve that shuts off the end of the air supply circuit 6 and opens the end of the exhaust circuit 8 to the atmosphere.

The air supply circuit 6 is connected to an air source 11 via a shutoff valve 10, and the tanks 3A, 3B, 3C are provided with pressure sensors 12A, 12B, 12C.

The supply / exhaust valves 4A, 4B, 4C, the connecting valve 9, the shutoff valve 10, and the pressure sensors 12A, 12B, 12C are connected to the control unit 13 shown in FIG. It has a section 14.

The control device 13 includes an air pressure detection unit 15 and an air pressure storage unit 1.
6 ,. Pipeline air pressure calculation unit 17, air distribution procedure creation unit 18,
An air distribution procedure storage unit 19 and a valve switching drive unit 20 are provided, and an input operation unit 14 is provided with a next air pressure setting unit 21, a start command unit 22, and an air pressure final adjustment unit 23.

The air pressure detector 15 detects the air pressure in the tanks 3A, 3B, 3C based on the signals from the pressure sensors 12A, 12B, 12C. The air pressure storage unit 16 stores the current and next air pressures of the tanks 3A, 3B, 3C.

The pipeline air pressure calculation unit 17 switches the three supply / exhaust valves 4A, 4B, 4C, the connecting valve 9, and the shutoff valve 10 to the three tanks 3A, 3B, 3C.
For each of the cases where two of them are in a communication state by an arbitrary combination, the pipeline air pressure of the air supply circuit 6 and the exhaust circuit 8 (the air pressure when the two communicated tanks have the same pressure) ) Is theoretically calculated, and in this calculation unit 17, one of the two tanks that were initially in communication and one that was not first in communication were The pipe line air pressure when the individual tanks are communicated next is also calculated. Such calculation of the pipe line air pressure can be theoretically obtained from the original air pressures of the two tanks in the communicating state and the tank capacity including the capacities of the air supply circuit 6 and the exhaust circuit 8.

The air distribution procedure creation unit 18 uses the calculation result of the pipeline air pressure calculation unit 17 and the tank 3 stored in the air pressure storage unit 16.
Based on the next air pressure of A, 3B, 3C, 3 tanks 3A,
The purpose is to find out which two tanks of 3B and 3C are in the communication state first, and then which two tanks are in the communication state, so that the air pressure adjustment work can be completed in the shortest time, that is, The air distribution procedure creating unit 18 creates a procedure for distributing air between tanks.

Here, in creating the procedure for distributing the air between the tanks in the creating unit 18, as shown in FIG.
The two tanks, which were P ₁ and P ₂ , have the same pressure P ₀ (the above-mentioned pipeline air pressure calculated by the calculation unit 17), but do not make it on condition that air flows in. It is made on the condition that the air pressure in the tank on the side becomes a predetermined pressure of P ₄ which leaves P ₃ for P ₀ . This P ₃ is, for example, 0.5 to 1 kgf / cm ²
Is.

In this embodiment, the procedure for distributing the air created by the creating unit 18 in this way is to supply the air from the high-pressure tank 3A to the low-pressure tank 3B by first connecting the tanks 3A and 3B to each other, and then to the tanks 3A and 3C. It is assumed that air is supplied from the tank 3A, which is still in a high pressure tank in the communicating state, to the low pressure tank 3C.

The air distribution procedure storage unit 19 stores the distribution procedure of air created by the creation unit 18. The valve switching drive unit 20 performs the initial switching of the supply / exhaust valves 4A, 4B, 4C, or when the pressure of the tank on the air supply side reaches a predetermined pressure (P _{4 in} FIG. 3). The air supply / exhaust valves 4A, 4B, 4C are switched in accordance with the air distribution procedure stored in the storage unit 19 based on the signal from the air pressure detection unit 15 that has detected The shutoff valve 10 is also switched.

The next air pressure setting unit 21 is for setting the next air pressure of the tanks 3A, 3B, 3C, and the set air pressure is stored in the air pressure storage unit 16. Start command unit 22
Is a command to start switching of the supply / exhaust valves 4A, 4B, 4C, the connecting portion 9, and the shutoff valve 10 by the valve switching drive unit 20.
The air pressure final adjusting unit 23 switches the air supply / exhaust valves 4A, 4B, 4C, the connecting valve 9, and the shutoff valve 10 by the valve switching drive unit 20 by, for example, an operation operation, whereby the air pressure of the tanks 3A, 3B, 3C is changed. Eventually change the pressure to be equal to the next air pressure.

Next, the operation will be described.

The next air pressure of the tanks 3A, 3B, 3C is set by the next air pressure setting unit 21 while drawing is being performed by the transfer press machine, and this is stored in the air pressure storage unit 16. As a result, the pipeline air pressure calculation unit 17 performs the above calculation, and the air distribution procedure creation unit 18 creates a distribution procedure of air between tanks, which is stored in the storage unit 19.

After completion of the drawing work, the switching valves 2A, 2B, 2C are in the positions 2Ab, 2Bb, 2C.
Switched to b, the moving bolster moves to the mold change position.

Next, when the start command unit 22 is operated, the valve switching drive unit
The connecting valve 9 is switched to the position 9a by 20 so that the air supply circuit 6 and the exhaust circuit 8 are in communication with each other, and the shutoff valve 10 is switched to the position 10a to be in the shutoff state, and further stored in the storage unit 19. Exhaust valve according to the air distribution procedure
Switching of 4A, 4B, 4C begins.

That is, in this embodiment, first, the intake / exhaust valve 4A is moved to the position 4Ac.
The air in the high-pressure tank 3A is switched to the supply / exhaust valve 4B position 4Ba, and the air in the high-pressure tank 3A is supplied to the supply / exhaust valve 4A, the check valve 7A, the exhaust circuit 8, the connecting valve 9, the supply circuit 6, the check valve 5B, and the supply / exhaust valve. It flows into the low-pressure tank 3B through the valve 4B, and the air pressure in this tank 3B gradually increases. When this air pressure reaches a predetermined value corresponding to P ₄ in FIG. 3, a signal relating to this air pressure is input from the air pressure detection unit 15 to the valve switching drive unit 20, so the supply / exhaust valve
4B is switched to position 4Bb, which stops the supply of air to tank 3B.

The time during this period is T ₁ in FIG. 3, and it is not necessary to wait until the time T _{2 at} which the air pressure in the tank 3B becomes a pressure corresponding to P ₀ , so the working time can be shortened.

The supply / exhaust valve 4B is switched to the position 4Bb, and at the same time, the supply / exhaust valve 4C is switched to the position 4Ca, whereby the air check valve 5 of the high-pressure tank 3A reaching the supply circuit 6 as described above.
C, flows into the low-pressure tank 3C through the air supply / exhaust valve 4C, and the air pressure in this tank 3C gradually increases. This air pressure is also detected by the air pressure detection unit 15, and this detection signal is sent to the valve switching drive unit.
Since it is input to 20, when the air pressure in the tank 3C reaches a predetermined value corresponding to P ₄ in FIG. 3, the intake / exhaust valve 4C is switched to the position 4Cb, and the intake / exhaust valve 4A is also switched to the position 4Ab. Further, the connecting valve 9 is switched to the position 9b and the shutoff valve 10 is switched to the position 10b.

In this way, the working time can be shortened even when the air is supplied from the tank A to the tank C.

Next, the air pressure final adjustment unit 23 is operated to operate the valve switching drive unit 20.
The air supply / exhaust valves 4A, 4B, 4C are switched to arbitrary positions by this, and air is supplied from the air source 11 to the tank whose air pressure is still lower than the next set air pressure. , From the tank whose air pressure is still higher than the next air pressure, the air is exhausted to the atmosphere from the connecting valve 9 at the end of the exhaust circuit 8, so that each tank can be accurately pressured at the next air pressure. To

Since the final adjustment work of the air pressure of the tank performed in this way corrects a slight excess or deficiency of the air pressure, it can be completed in a short time.

After completing the above work, set the intake / exhaust valves 4A, 4B, 4C to positions 4Ab, 4Bb, 4C.
By switching to b and switching the switching valves 2A, 2B and 2C to the positions 2Aa, 2Ba and 2Ca, preparation for the next drawing process is completed.

According to the present embodiment described above, the supply of air to the low-pressure tank is stopped without waiting for the air pressures of the two tanks in the communication state as described above to become the same, so that the working time is shortened. Be promoted. In addition to this, the air supply to the low-pressure tank is stopped based on the signal that detects the air pressure in the low-pressure tank, so the air supply to the low-pressure tank is uniformly stopped after the time set by the timer has elapsed. Different from the case where the original air pressure of the tank (corresponding to P ₁ and P ₂ in Fig. 3) is set differently, it is necessary to supply a sufficient amount of air to the low pressure tank. The problem that the connecting valve 9 is switched after the air pressures of the two tanks become the same pressure does not occur, and appropriate control is performed according to the respective air pressures. Even with such a configuration, it is possible to save energy and shorten the air pressure adjustment time.

Further, according to the present embodiment, the next air pressure can be set by the next air pressure setting unit 21 while the previous drawing work is being performed, and immediately by operating the start command unit 22 at the time of mold replacement. Since the air distribution work between the tanks can be performed, the work efficiency can be improved in this respect as compared with the conventional device shown in FIG.

In the above embodiment, the air pressure of the low pressure tank is detected and the supply of air to the low pressure tank is stopped.
Even if this is performed by detecting the air pressure in the high-pressure tank, the same effect as described above can be obtained. Further, in the above-mentioned embodiment, two of the three tanks are placed in the communication state by dividing the time,
These were put into communication at the same time, and the air pressure in the low-pressure tank or high-pressure tank reached a specified value with respect to the pipeline air pressure in the air supply circuit and exhaust circuit calculated from all the original tank air pressure and tank capacity. At times, the supply of air to the low pressure tank may be stopped. In this case, the air distribution procedure creation unit 18 and the air distribution procedure storage unit 19 in the above embodiment are not required, and the calculation result by the pipe air pressure calculation unit 17 is directly input to the valve switching drive unit 20.

Therefore, the configuration of the control device is determined according to the required function, and is not limited to that of the above embodiment, the control device may also control the switching valves 2A, 2B, 2C of the above embodiment. .

Further, although the number of die cushions is three in the above-mentioned embodiment,
Of course, the device according to the invention can also be applied to a press machine having more or less die cushions.
Further, the device according to the present invention can be applied not only to the air cylinder for die cushion but also for adjusting the air pressure of the air cylinder for knockout provided on the slide of the press machine, for example.

[Effect of device]

According to the present invention, it is possible to achieve both the energy saving and the shortening of the air pressure adjustment time.

[Brief description of drawings]

FIG. 1 is a diagram showing an air circuit of an apparatus according to an embodiment of the present invention, FIG. 2 is a control block diagram thereof, and FIG. 3 is an air pressure of a tank showing time for stopping supply of air to a low pressure tank. FIG. 4 is a change diagram, and FIG. 4 is an air circuit diagram showing a conventional device. 1A, 1B, 1C …… Air cylinder, 3A, 3B, 3C …… Tank, 4A, 4
B, 4C …… Supply / exhaust valve, 6 …… Supply circuit, 8 …… Exhaust circuit,
9 ... Connection valve, 10 ... Shutoff valve, 11 ... Air source, 13 ... Control device, 15 ... Air pressure detection unit, 17 ... Pipe line air pressure calculation unit, 20 ... Valve switching drive unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area F15B 11/064 21/14

Claims (1)

[Scope of utility model registration request] 1. A tank is provided for each air cylinder, and an air supply circuit and an exhaust circuit are connected to these tanks via an air supply / exhaust valve, and the air supply circuit and the exhaust circuit are connected by a connecting valve. In an air pressure adjusting device for a plurality of air cylinders, which can communicate with each other and shut off freely, and which connects the air supply circuit to an air source through a shutoff valve, a control device is connected to the air supply / exhaust valve, and a plurality of air pressure control devices are connected to the control device. A pipeline air pressure calculation unit that calculates the pipeline air pressure in the air supply circuit and the exhaust circuit when the tank is in communication from the original tank air pressure and the tank capacity, and the connection valve by switching the supply / exhaust valve. Air is supplied from the high-pressure tank to the low-pressure tank via the air supply circuit and the exhaust circuit communicated with each other, and when the air pressure in the tank reaches a predetermined value with respect to the pipeline air pressure, Based on air pressure signal Air pressure regulator of the plurality of air cylinders, characterized and can the valve switching drive unit for stopping the supply of air to the low pressure tank, that was provided.