JPH0735801B2 - Pressure converter using residual pressure of double-acting cylinder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a residual pressure of a double-acting cylinder that effectively utilizes a differential pressure between a pressure required during operation of the double-acting cylinder and a pressure required during stoppage. The present invention relates to a pressure conversion device using the.

(Prior Art) The required pressure 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, the piston rod requires a high pressure during the ingress / egress operation due to the inertial resistance of the load object connected to the rod and the outflow resistance of the air on the exhaust side of the double-acting cylinder, but at the time of stop, these There is no resistance, and only the pressure required to hold the static load is required.

If the double-acting cylinder operates horizontally, the static friction resistance of the load is sufficiently large, or if the double-acting cylinder has a lock mechanism, the supply pressure required during operation and the supply pressure required during stop will differ. There is a large pressure difference, and in the past, this pressure difference was either discarded as residual pressure as it is, or was not used and was retained in the cylinder until the next operation.

On the other hand, in the factory, in addition to the general-use pressure supplied from one air pressure source, there are not a few general-use pressures that require a higher working pressure than the general-purpose pressure. In some places, it was necessary to boost the pressure with a separate high pressure compressor or the like.

(Problems to be solved by the invention) However, it is very wasteful in terms of energy economy to release all the residual pressure of these double-acting cylinders used in many factories into the atmosphere. It became resistance and wasted energy twice.

Further, if a high-pressure compressor is separately provided at the high-pressure end that is higher than the pressure used in a general factory, there is a problem in that equipment costs increase and extra power is consumed, resulting in higher costs.

The present invention has been made in view of such a conventional problem, and by making good use of the residual pressure of the double-acting cylinder with a simple circuit, not only is the excess energy recovered, but further progress is made. It is an object of the present invention to provide a pressure conversion device that uses the residual pressure of a double-acting cylinder, such as enabling high-pressure air to be supplied to a high-pressure use end that is higher than the pressure for general use.

(Means for Solving the Problems) In order to solve the above problems, the gist of the present invention is that the inlet side port receives pressurized air from an air pressure source and the outlet side port is the cap side of the double-acting cylinder. And a switching valve for performing a switching operation that communicates with each port on the head side, and is connected to the both 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 operation of the dynamic cylinder is stopped, the residual pressure supply valve that is open to at least the pressurizing side port of the double acting cylinder and the large diameter piston and the small diameter piston are built in and the residual pressure is supplied to the drive chamber side. A pressure converter for sending out pressure air whose pressure has been converted in a pressure conversion chamber by receiving the residual pressure of the double-acting cylinder via a valve, and an opening valve for releasing the drive chamber to a predetermined pressure when the conversion operation by the pressure converter is completed. And The present invention is a pressure conversion device utilizing the residual pressure of a double-acting cylinder.

(Operation) When the switching valve is switched to one side, the piston rod of the double-acting cylinder starts the output operation or the input operation. Pressurized air enters the pressurization side and is expelled from the opposite side of the piston. During this time, the residual pressure supply valve is in the closed position with respect to the double-acting cylinder.

When the piston of the double-acting cylinder comes to the stroke end and a signal is generated based on the detection result of the limit switch or the like, the switching valve is in the intermediate position, and the pressure supply port to the double-acting cylinder is shut off.

On the other hand, the residual pressure supply valve is switched to a position communicating with the port of the double-acting cylinder which has been on the pressurizing side by the signal.
Then, this residual pressure is supplied to the drive chamber of the pressure converter through the residual pressure supply valve.

Pressure air is supplied from the air pressure source to the pressure conversion chamber side of the pressure converter, the piston is pushed by the residual pressure supplied to the drive chamber, the piston of the pressure converter operates, and The pressure-converted pressure air is sent out.

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

When the piston of the pressure converter reaches the stroke end and the delivery of pressurized air stops, the opening valve provided on the outlet side of the residual pressure supply valve opens, and the residual pressure remaining is released to the atmosphere, 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 direction opposite to the above direction and then stops, the residual pressure supply valve switches to the opposite direction and performs the same operation. .

(Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings by taking as an example the case of increasing the pressure using a double-acting cylinder arranged along the vertical direction.

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

The pressure conversion device 10 utilizing the residual pressure of the double-acting cylinder includes a double-acting cylinder 20, a switching valve 30 for switching the operating direction of the double-acting cylinder 20, and a residual pressure supply valve for supplying the residual pressure of the double-acting cylinder 20. 40, a pressure converter 50 that operates by receiving the residual pressure and sends out pressurized air, and an opening valve 60 that opens the residual pressure to the atmospheric pressure which is the predetermined pressure in this case.

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

The load object W is connected to the lower end of the piston rod 23, and the limit switches 61, 6 for detecting the stroke end are detected.
2 is provided corresponding to the position of the load object W.

The switching valve 30 is a closed center type of a 5-port 3-position switching valve, and the inlet port ₁ is the air pressure source S via the check valve 63 and the outlet port C ₁ is the head side port of the double-acting cylinder 20.
In FIG. 25, the outlet port C ₂ communicates with the cap port 24, respectively, and the ports R ₁ and R ₂ are both open to atmospheric pressure.

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

The residual pressure supply valve 40 is a closed center type of 3-port 3-position switching valve, and the inlet side port D ₁ and the inlet side port D ₂ are the head side port 25 and the cap side port of the double acting cylinder 20, respectively.
The outlet port P ₂ communicates with the residual pressure line 64 leading to the pressure converter 50.

Although not shown, the residual pressure supply valve 40 is also operated by a solenoid, for example.

The pressure converter 50 is located in the large-diameter cylinder body 51a and is located in the drive chamber 5
A large-diameter piston 52 that receives residual pressure in 1 and a small-diameter piston that is connected to the large-diameter piston 52 by a connecting rod 53 and that is in a small-diameter cylinder body 54a and that generates high pressure in the pressure conversion chamber 54
55, 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, and the other one. Check valve
Reference numeral 66 is for sending out high-pressure air whose pressure is increased in the pressure conversion chamber 54. A high-pressure air tank 13 is connected to the high-pressure side pipeline 12, and the outlet side of the high-pressure air tank 13 communicates with the inlet port P ₁ of the switching valve 30 through the pipeline 14.

On the other hand, the residual pressure line 64 has a pressure switch for detecting residual pressure.
67 and a solenoid operated open valve 60 are provided.

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

Assuming that the operation is started from the state where the piston rod 23 is fully projected as shown by the solid line in FIG. 1, the switching valve 30 is switched from the central position to the position indicated by B, and the operating pressure is changed to the inlet port P. _The piston rod 23 fed from ₁ to the head-side port 25 of the double-acting cylinder 20 through the outlet-side port C ₁ performs an inserting operation.

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

When the piston rod 23 reaches the position shown by the chain double-dashed line and the load object W reaches the limit switch 61, the switching valve 30 is returned to the central position by the signal of this limit switch 61, and the supply of pressurized air is stopped. To be done. On the other hand, the residual pressure supply valve 40 is switched to the position A by the signal of the limit switch 61.

Since the high air pressure during the operation remains as residual pressure on the head side of the cylinder 20, the residual pressure is changed from the port 25 to the inlet port D ₁ of the residual pressure supply valve 40 by the switching of the residual pressure supply valve 40. It reaches the outlet side port P ₂ through, is fed into the driving chamber 51 of the pressure transducer 50 through the residual pressure line 64. Then, the large-diameter piston 52 is pressed, the pressure air in the pressure conversion chamber 54, which has been previously sent from the air pressure source, is further raised by the small piston 55, and the high pressure air tank 13 is passed through the check valve 66.
Send in.

When the operation of the large-diameter piston 52 ends 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 central position, The release valve 60 is opened to open it to the atmospheric pressure, and the open valve 60 is closed again by the signal of the pressure sensor (not shown) indicating that the inside of the residual pressure line 64 has become the atmospheric pressure, to prepare for the next operation.

On the other hand, since the pressure in the residual pressure line 64 becomes low, the air from the air pressure source S is supplied from the check valve 65 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 drawing. It is moved and this is also ready for the next operation.

With the piston rod 23 fully inserted, this time switch valve 30
Is switched to the position of A, pressurized air is supplied through the port 24 on the cap side, and when the rod 23 projects and reaches the stroke end, the signal of the limit switch 62 causes the switching valve 30 to return to the central position and simultaneously supply residual pressure. The valve 40 is switched to the position B and the residual pressure is supplied from the inlet port D ₂ , and the subsequent operation is the same as that described above.

The high pressure from the high-pressure air tank 13 is the switching valve 30 in this embodiment.
Is supplied to the inlet port side of the above, but this is only one embodiment, and it is also possible to branch from the high pressure air tank 13 and couple each to the required use terminal.

Instead of detecting the end of the operation of the pressure converter 50 by the pressure switch 67 provided in the residual pressure line 64, the operation of the piston block 56 of the pressure converter 50 may be directly detected by a proximity switch or the like.

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

In the case of the second embodiment, the switching valve 70 is an exhaust center type of a five-port three-position switching valve, the residual pressure supply valve 80 is a closed center type of a three-position switching valve, and the opening valve 60 has a flow rate and a pressure. A throttle 91 for adjustment and a relief valve 90 are connected. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The switching valve 70 connects the two ports Q ₁ and Q ₂ to the head side port 25 and the cap side port 24 of the double-acting cylinder 20, respectively,
The other two ports E ₁ and E ₂ are connected to the residual pressure supply valve 80, and the central port E ₀ is connected to the air pressure source S.
S ₁ and S ₂ are provided. The switching valve 70 is in the central position and has ports E ₁ ,
E ₂ communicates with the head side port 25 and the cap side port 24 of the double-acting cylinder 20.

Solenoid S ₃ is the residual pressure supply valve 80, S _4, the open valve 60 is solenoid S ₅ is provided.

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

For example, it is assumed that the piston rod 23 of the double-acting cylinder 20 starts its operation from the state where it is at the lower stroke end shown by the solid line in FIG.

Turn on solenoids S ₁ , S ₄ and S ₅ , set switching valve 70 to position A,
When the residual pressure supply valve 80 is in the position B and the open valve 60 is in the open position,
Pressure air reaches the head side port 25 from the air pressure source S through the port E ₀ and the port Q ₁ , and the piston block 23 is put into operation by this pressure air.

On the other hand, when the open valve 60 is already opened, the check valve 65 to the air pressure source S
Is supplied into the pressure conversion chamber 54 of the pressure converter 50, and the piston block 56 moves to the residual pressure line side.

When the piston rod 23 reaches the upper stroke end 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 S ₁ and S ₄ are turned off, and the switching valve 70 and residual pressure supply valve 80 are in the center position. Next, the solenoid S ₃ is turned on and S ₅ is turned off, and the head side pressure of the double-acting cylinder 20 is sent to the drive chamber 51 of the pressure converter 50 through the residual pressure line 64 through the ports F ₁ and Q ₃ to convert the pressure. The device 50 operates and the head side pressure of the double-acting cylinder 20 decreases. Then, when the minimum predetermined pressure necessary only for holding the load object W at the same position is reached, the solenoid S ₃ is turned off and the solenoid S ₅ is turned on by a signal from the pressure switch 67 which detects this. The double-acting cylinder 20 holds the position of the stroke end above the piston rod 23, and the pressure in the residual pressure line 64 is controlled by the release valve 60 and the throttle valve 9.
1. The pressure is released to the atmospheric pressure through the relief valve 90, the pressure air is sent into the pressure conversion chamber 54 through the check valve 65, and the pressure converter 50 is reset.

A signal from a pressure sensor (not shown) indicating that the pressure inside the residual pressure line 64 has reached atmospheric pressure causes S ₅ to be turned off and the on-off valve 60 to be closed.

In the next step, the solenoids S ₂ and S ₃ are turned on and the air pressure source S
From port E ₀ and port Q ₂ to reach the cap side port 24, and this pressure air causes the piston rod
Operate 23.

That is, the pressure air on the head side of the double-acting cylinder 20 passes through the switching valve 70 and the residual pressure supply valve 80 and then through the residual pressure line 64 to the pressure converter.
The pressure is sent to the drive chamber 51 of 50, the pressure converter 50 operates, and the head side pressure of the double-acting cylinder 20 decreases. During this time the solenoid S ₅ is off and the open valve 60 is in the closed position.

If the operating speed of the double-acting cylinder cannot be maintained during this operation, the solenoid S ₅ is turned on, and the throttle 91 and the relief valve 90 are adjusted and operated, respectively.
Can be operated up to the stroke end at the required speed. The subsequent operation is the same as described above.

The present invention can be applied not only to the case of increasing the pressure but also to the case of decompressing the air with the pressure converter, and the piston rod of the double-acting cylinder operates not only in the vertical direction but also in any direction. It may be.

(Effects of the Invention) The present invention is configured as described above, and the difference in the required pressure between when the double-acting cylinder is operating and when it is stopped, that is, the residual pressure is extracted with a simple circuit configuration and is guided to the pressure converter to generate high pressure and the like. As a result, not only does it contribute greatly to the power saving of the factory, but it also makes it possible to supply low-cost high-pressure air to the use end having a higher pressure than the general-purpose air source.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a pressure conversion device utilizing 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 conversion device according to a second embodiment of the present invention. Is. P ₁ …… Inlet port, C ₁ , C ₂ …… Outlet port, S …… Air pressure source, W …… Loaded 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 converter, 51 ...
… Drive chamber, 52 …… Large-diameter piston, 54 …… Pressure conversion chamber, 55
...... Small diameter piston, 56 ...... Piston block, 60 ...... Open valve, 64 ...... Residual pressure line, 70 ...... Switching valve, 80 ...... Residual pressure supply valve, 90 ...... Relief valve, 91 ...... Throttle.

Claims (1)

[Claims] 1. A switching valve for performing a switching operation for receiving pressurized air from an air pressure source into an inlet port and communicating the outlet port with each of the cap-side and head-side ports of a double-acting cylinder; It is connected to both ports and is in a closed position for the double-acting cylinder during operation of the double-acting cylinder, and at least for the port on the pressurizing side among the both ports of the double-acting cylinder when the operation of the double-acting cylinder is stopped. The residual pressure supply valve in the open position, a large-diameter piston and a small-diameter piston are built-in, and the residual pressure of the double-acting cylinder is passed through the residual pressure supply valve on the drive chamber side to receive the pressure air converted in the pressure conversion chamber. A pressure converter using a residual pressure of a double-acting cylinder, comprising: a pressure converter for sending out; and an opening valve for opening the drive chamber to a predetermined pressure when a conversion operation by the pressure converter is completed.