JPH01295006A - Pressure converter using remaining pressure in double acting cylinder - Google Patents

Abstract

PURPOSE:To recover excess energy by extracting remaining pressure in a double acting cylinder, leading it to a pressure converter and obtaining high pressure. CONSTITUTION:A pressure converter 10 using remaining pressure in a double acting cylinder, is composed of a switch valve 30, a remaining pressure supply valve 40, a pressure converter 50 operating by remaining pressure and supplying boosted pressure air and an open valve 60 for opening the remaining pressure to the atmosphere. Consequently, the excess energy can be recovered and an inexpensive, high pressure air can be supplied to an end using higher pressure than general air sources because high pressure can be obtained from the remaining pressure.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is directed to reducing the residual pressure of a double-acting cylinder by effectively utilizing the differential pressure between the pressure required during operation of the double-acting cylinder and the pressure required when the cylinder is stopped. The present invention relates to a pressure transducer using a pressure converter.

(Prior art) The required pressure to be supplied to a double-acting cylinder used to move an object is different when the object is moving and when it is stopped. That is, when the piston rod is moving in and out, High pressure is required due to the inertial resistance of the load connected to the cylinder and the outflow resistance of the air on the exhaust side of the double-acting cylinder, but when the cylinder stops, these resistances disappear and the pressure required to maintain the static load is increased. All you need is pressure.

If the double-acting cylinder operates in a horizontal direction, the static friction resistance of the load is sufficiently large, or the double-acting cylinder is equipped with a locking device next to it, the supply pressure required during operation and the required supply when stopped. There is a large pressure difference between the pressure and the pressure, and conventionally, this differential pressure was either discarded as residual pressure or was held in the cylinder without being used until the next operation.

On the other hand, in addition to the operating end of the factory that uses general pressure supplied from the - pneumatic source, there are also many operating ends that require operating pressure higher than the general pressure, and conventionally such high pressure At some points, it was necessary to boost the pressure using a separate high-pressure compressor.

(Problem to be solved by the invention) However, releasing all the residual pressure of these double-acting cylinders, which are used in large numbers in factories, into the atmosphere would be extremely wasteful in terms of energy economy, and it would be extremely wasteful in terms of energy economy. It acted as a resistance force, doubly wasting energy.

Further, if a separate high-pressure compressor is provided at the high-pressure end, which is higher than the pressure used in a general factory, there are problems in that equipment costs increase and extra power is consumed, leading to higher costs.

The present invention was made in view of these conventional problems, and it not only aims to recover surplus energy by effectively utilizing the residual pressure of a double-acting cylinder with a simple circuit, but also goes further. It is an object of the present invention to provide a pressure conversion device that utilizes the residual pressure of a double-acting cylinder, which makes it possible to supply high-strength air to a high-pressure use end that is higher than the pressure for -i.

<Means for Solving the Problems> In order to solve the above problems, the gist of the present invention is to receive pressurized air from an air pressure source at the inlet port, and connect the outlet port to the cap side of the double-acting cylinder. and a switching valve that performs a switching operation to communicate with each port on the head side, and a switching valve that is connected to both the ports of the double-acting cylinder and is in a closed position with respect to the double-acting cylinder during operation of the double-acting cylinder. When the double-acting cylinder stops operating, it has a built-in residual pressure supply valve that opens to at least the pressure-side port of both ports of the double-acting cylinder, a large-diameter piston, and a small-diameter piston, and the residual pressure is supplied to the drive chamber side. a pressure converter that receives the residual pressure of the double-acting cylinder via a supply valve, converts the pressure in a pressure conversion chamber, and sends out pressurized air; and an opening that releases the drive chamber to a predetermined pressure when the conversion operation by the pressure converter is completed. The present invention provides a pressure conversion device using residual pressure of a double-acting cylinder, characterized by comprising a valve.

(Operation) When the switching valve is switched to one side, the piston rod of the double-acting cylinder starts to move out or move in.

Pressurized air enters the pressurized side, and air is exhausted from the opposite side of the piston. During this time, the residual pressure supply valve is in the closed position relative to the double acting cylinder.

When the piston of the double-acting cylinder reaches its stroke end and a signal is issued based on a detection result by a limit switch or the like, the switching valve becomes an intermediate position and cuts off the pressure supply port to the double-acting cylinder.

On the other hand, the signal causes the residual pressure supply valve to switch to a position where it communicates with the port of the double-acting cylinder, which has been on the pressurizing side.

This residual pressure is then supplied to the drive chamber of the pressure converter through the residual pressure supply valve.

Pressure air is supplied from an air pressure source to the pressure conversion chamber side of the pressure transducer, and the piston is pushed by the residual pressure supplied to the drive chamber, the piston of the pressure transducer operates, and the pressure conversion chamber side is supplied with pressurized air. It sends out compressed air that has been converted to a pressure of

Pressurized air sent out from the pressure conversion chamber is stored in an air tank or the like and supplied to the end of use.

When the piston of the pressure transducer reaches the stroke end and the delivery of pressurized air stops, the release valve installed on the outlet side of the residual pressure supply valve opens, and the remaining residual pressure is released to the atmosphere, and the remaining pressure is released into the drive chamber and the residual pressure circuit. Bring the inside to the specified pressure.

When the switching valve switches to the other direction and the double-acting cylinder operates in the opposite direction to the above-mentioned direction and then stops, the residual pressure supply valve switches to the opposite direction and performs the same action. .

(Embodiment) A first embodiment of the present invention will be described below with reference to the drawings, taking as an example a case in which pressure is increased using a double-acting cylinder arranged along the vertical direction.

FIG. 1 is a circuit diagram showing a first embodiment of a pressure converting device using the residual pressure of a double-acting cylinder according to the present invention.

A pressure conversion device 10 that uses the residual pressure of a double-acting cylinder includes a double-acting cylinder 20, a switching valve 30 that switches the operating direction of the double-acting cylinder 20, and a residual pressure supply valve that supplies the residual pressure of the double-acting cylinder 20. 40, a pressure converter 50 that operates upon receiving residual pressure and sends out pressurized air, and a release valve 60 that releases the residual pressure to atmospheric pressure, which is a predetermined pressure in this case.

The double-acting cylinder 20 includes a cylinder body 21, a piston 22 that slides under pressure within the cylinder body 21, and a piston rod 23 connected to the piston 22, and a cap side port 24 and a head. A side port 25 is provided.

The piston rod 23 has a load object W connected to its lower end, and a limit switch 61 that detects the end of the stroke.
．． 62 is provided corresponding to the position of the load object W.

The switching valve 30 is a closed center type 5-point, 3-position switching valve, in which the inlet port P1 is connected to the air pressure source S via the check valve 63, and the outlet port c1 is connected to the head side of the double-acting cylinder 20. In the port 25, an outlet port C2 communicates with the cap side port 24, and both ports RI and R2 are open to atmospheric pressure.

Although not shown, the switching means of the switching valve 30 may be a solenoid, a manual switch, or any other means.

The residual pressure supply valve 40 is a closed center type three-bottom, three-position switching valve, and the inlet port D1 and the inlet port D2 communicate with the head side port 25 and cap side port 24 of the double-acting cylinder 2o, respectively. The outlet port P2 communicates with a residual pressure conduit 64 leading to the pressure transducer 5o.

Although the operating means for the residual pressure supply valve 40 is not shown, it is operated using, for example, a solenoid.

The pressure transducer 50 includes a large-diameter piston 52 that is located within the large-diameter cylinder body 1a and receives residual pressure within the drive chamber 51, and a large-diameter piston 52 that is connected to the large-diameter piston 52 by a connecting rod 53 and that is located within the small-diameter cylinder body 4a. The large diameter piston 52, the small diameter piston 55, and the connecting rod 53 form a piston block 56.

A pair of check valves 65 and 66 are connected to the outlet port of the pressure conversion chamber 54, and one check valve 65 supplies the pressure from the air pressure source S to the pressure conversion chamber 54 through the pipe line 11.
The other check valve 66 is for sending out high pressure air pressurized within the pressure conversion chamber 54. A high-pressure air tank 13 is connected to this high-pressure side pipe line 12.
The outlet side of the high-pressure air tank 13 communicates with the inlet port P1 of the switching valve 30 through a conduit 14.

On the other hand, the residual pressure conduit 64 is provided with a pressure switch 67 for detecting residual pressure and a solenoid-operated release valve 6°.

Next, the operation of the pressure conversion device using the residual pressure of the double-acting cylinder according to the above embodiment of the present invention will be explained.

Assuming that the operation starts from the state in which the piston rod 23 is fully protruded as shown by the solid line in FIG.
The switching valve 30 is switched from the center position to the position indicated by B,
The operating pressure is inlet port P! The piston rod 23 is fed into the head side port 25 of the double-acting cylinder 2° through the outlet port C1, and the piston rod 23 enters.

During this time, the residual pressure supply valve 40 maintains the central position.

When the piston rod 23 is fully inserted and reaches the position shown by the two-dot chain line, and the load object W reaches the limit switch 6], the switching valve 30 returns to the center position by the signal from the limit switch 61, and the supply of pressurized air is stopped. will be stopped. And on the other hand,
The residual pressure supply valve 4o is activated by the signal from the limit switch 61.
is switched to position A.

Since the high air pressure during operation remains as residual pressure on the head side of the cylinder 20, by switching the residual pressure supply valve 40 as described above, the residual pressure is transferred from the port 25 to the inlet port D of the residual pressure supply valve 4o.

It reaches the outlet port P2 through the residual pressure line 64 and is sent into the drive chamber 51 of the pressure transducer 50. Then, the large-diameter piston 52 is pressed, and the pressure air in the pressure conversion chamber 54, which has been sent in advance from the air pressure source, is further increased in pressure by the small piston 55, and is sent into the high-pressure air tank 13 through the check valve 66.

When the operation of the large diameter piston 52 is completed and the pressure in the residual pressure line 64 reaches a predetermined pressure, the pressure switch 67 detects this and issues a signal, switching the residual pressure supply valve 40 to the center position, The release valve 60 is opened to release to atmospheric pressure, and the residual pressure line 6
The release valve 60 is closed again in response to a signal from a pressure sensor (not shown) indicating that the pressure inside the valve 4 has reached atmospheric pressure, and prepares for the next operation.

On the other hand, due to the low pressure inside the residual pressure pipe 64, the check valve 6
5, air from the pneumatic pressure source S is supplied into the pressure conversion chamber 54 of the pressure converter 50, and the piston block 56 is moved to the left end side in the figure, and preparation for the next operation is also completed.

When the switching valve 30 is switched to position A with the piston rod 23 fully inserted, pressurized air is supplied through the cap side port 24, and when the rod 23 protrudes and reaches the stroke end, the signal from the limit switch 62 is activated. The switching valve 30 returns to the center position, and at the same time the residual pressure supply valve 40
The switch is switched to position B, and residual pressure is supplied from the inlet port D2, and the subsequent operation is the same as described above.

In this embodiment, the high pressure from the high pressure air tank 13 is supplied to the inlet port side of the switching valve 30.
This is just one embodiment, and a pressure switch 67 provided in the residual pressure line 64 is used to terminate the operation of the pressure transducer 50, which can be branched from the high-pressure air tank 13 and connected to each necessary terminal. Instead of detecting by
Actuation of the piston block 56 of the pressure transducer 50 may be detected directly by a proximity switch or the like.

FIG. 2 is a circuit diagram showing a pressure transducer according to a second embodiment of the present invention.

In the case of this second embodiment, the switching valve 70 is a 5-point, 3-position switching valve with a closed center type, the residual pressure supply valve 80 is a closed center type with a 3-position direct switching valve, and the open valve 80 is a closed center type of a 3-position direct switching valve.
0 is connected to a throttle 91 and a relief valve 90 for flow rate and pressure adjustment. The same parts as in the first embodiment are denoted by the same reference numerals, and the explanation thereof will be omitted.

The switching valve 70 connects two ports Q + and Q 2 to the head side port 25 and cap side port 24 of the double-acting cylinder 20, respectively, and connects the other two ports E1 and E2 to the residual pressure supply valve 80. , the central port LO is connected to a pneumatic source S, and solenoids S, , S2 are provided. The switching valve 70 is in the center position, and ports E, E2 are connected to the head side port 25 and cap side port 2 of the double acting cylinder 20.
It connects to 4.

The residual pressure supply valve 80 has a solenoid S3. S4, release valve 60
is equipped with a solenoid S5.

Next, the operation of the pressure converter according to the second embodiment of the present invention will be explained.

For example, the piston rod 23 of the double-acting cylinder 20
It is assumed that the operation starts from the lower stroke end shown by the solid line in the figure.

Solenoid S,, S2. When S5 is turned on, the switching valve 70 is set to position iA, the residual pressure supply valve 80 is set to position 2B, and the release valve 60 is set to the open position, air is transferred from the air pressure source S to port E. and port Q1
The pressurized air reaches the head side port 25 through the piston rod 25, and the piston rod 23 is moved into the piston rod 23 by this pressurized air.

On the other hand, due to the opening of the release valve 60, air from the air pressure source S is already supplied into the pressure conversion chamber 54 of the pressure converter 50 through the check valve 65, and the piston block 56 has moved toward the residual pressure line.

When the piston rod 23 reaches the stroke end in the -E direction as shown by the two-dot chain line, the limit switch 61 is turned on by the load object W, the piston rod 23 is stopped, the solenoids S1 and 84 are turned off, and the switching valve is turned on. 70 and the residual pressure supply valve 80 are placed in the center position. Next, solenoid S3
When S5 is turned on and S5 is turned off, the head side pressure of the double-acting cylinder 20 is sent to the drive chamber 51 of the pressure transducer 50 via the ports Fl and Q3 and the residual pressure pipe 64, and the pressure transducer 50
is activated, and the pressure on the head side of the double-acting cylinder 20 decreases. When the minimum predetermined pressure necessary only to hold the load object W in the same position is reached, a signal from the pressure switch 67 that detects this turns off the solenoid S3 and turns on the solenoid S5. The double-acting cylinder 20 maintains the upper stroke end position of the piston rod 23, and the pressure in the residual pressure line 64 is maintained between the open valve 60 and the throttle 91.
, is released to atmospheric pressure through the relief valve 90, and pressurized air is sent into the pressure conversion chamber 54 through the check valve 65, so that the pressure converter 50 is reset.

A signal from a pressure sensor (not shown) indicating that the inside of the residual pressure pipe 64 has reached atmospheric pressure turns S5 off, and the on-off valve 60
It's quiet.

The next step is solenoid S2. S3 is turned on, and pressurized air reaches the cap side port 24 from the air pressure source S through port EO and port Q2, and the piston rod 23 is moved out by this pressurized air.

That is, the head side pressure air of the double acting cylinder 20 is transferred to the switching valve 7.
0 and the residual pressure supply valve 80, and is sent to the drive chamber 51 of the pressure transducer 50 through the residual pressure line 64, and the pressure transducer 50
is activated, and the pressure on the head side of the double-acting cylinder 20 decreases. During this time, solenoid S5 is off, and release valve 60
is in the closed position.

If the operating speed of the double-acting cylinder cannot be maintained during this operation, turn on solenoid S5.

By adjusting and moving the throttle 91 and the relief valve 90, the piston rod 23 can be operated at a required speed to the stroke end. The subsequent operation is the same as described above.

Note that the present invention is applicable not only to pressure increase but also to pressure reduction of air using a pressure transducer, and the piston rod of a double-acting cylinder can move along any direction, not just vertically. There may be.

(Effects of the Invention) The present invention is configured as described above, and extracts the difference in the required pressure between when the double-acting cylinder is in operation and when it is stopped, that is, the residual pressure, with a simple circuit configuration and guides it to the pressure transducer, thereby converting the high pressure, etc. Not only does this greatly contribute to power savings in factories, but it also makes it possible to supply low-cost high-pressure air to the end of use, which has a higher pressure than a general air source.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a pressure converting device using the residual pressure of a double-acting cylinder according to a first embodiment of the present invention, and FIG. 2 is a circuit diagram showing a pressure converting device according to a second embodiment of the present invention. It is. Pl...input port, C,, C2...output port,
S... Air pressure source, W... Load object, 10... Pressure conversion device, 20... Double acting cylinder, 22... Piston, 23... Piston rod, 24... Cap side port , 25... Head side port, 30... Switching valve, 40... Residual pressure supply valve, 50... Pressure transducer, 51
... Drive chamber, 52... Large diameter piston, 54... Pressure conversion chamber, 55... Small diameter piston, 56... Piston block, 5 o... Open valve, 64... Residual pressure pipe ,
70...Switching valve, 80...Residual pressure supply valve, 90...Relief valve, 91... Throttle.

Claims (1)

[Claims] A switching valve that receives pressurized air from an air pressure source at an inlet port and performs a switching operation to connect the outlet port to each port on the cap side and the head side of the double acting cylinder, and is connected to both the ports of the double acting cylinder. The remaining portion is in a closed position with respect to the double-acting cylinder while the double-acting cylinder is in operation, and is in an open position with respect to at least the pressurizing side port of the two ports of the double-acting cylinder when the double-acting cylinder stops operating. A pressure converter that incorporates a pressure supply valve, a large-diameter piston, and a small-diameter piston, and sends pressurized air that receives the residual pressure of the double-acting cylinder through the residual pressure supply valve and converts the pressure in a pressure conversion chamber to the drive chamber side. and a release valve that opens the drive chamber to a predetermined pressure when the conversion operation by the pressure converter is completed.