JP3282308B2 - Fixing device for piston / sleeve type control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for fixing a piston-sleeve type control valve, and more particularly to a technique for temporarily fixing a flow rate when controlling a flow path.

[0002]

2. Description of the Related Art A piston-sleeve type control valve can accurately set an opening by linearly moving a valve body by fluid pressure applied to both sides of a piston.
It is applied to a fuel flow control device and the like.

On the other hand, when it is necessary to temporarily supply a certain amount of fluid such as fuel regardless of a change in servo pressure,
There may be a case where the movement of the piston is restricted.

As a method of restricting the movement of the piston, it has been considered to forcibly fix the piston with a large mechanical force.

[0005]

However, in the case of the method of fixing by mechanical force, the apparatus and equipment for that purpose tend to be large-scale, and in some cases, the piston or the sleeve may be damaged. Technical issues remain.

The present invention has been made in view of these problems, and has as its object to perform highly reliable fixing without being affected by a change in servo pressure.

[0007]

A plurality of means for solving the above problems are proposed. The first means is for temporarily fixing a piston-sleeve type control valve for controlling a flow path by moving a valve body by fluid pressure applied to a high pressure plenum portion and a low pressure plenum portion on both sides of a piston. In the case of a device, a shut-off valve interposed between two servo pressure supply paths sent to the piston-sleeve type control valve, and a working fluid which is connected to the shut-off valve and feeds the working fluid when the piston-sleeve type control valve is fixed. A high-pressure fluid supply means for shutting off the servo pressure supply path at the valve and a fluid connected to the low-pressure plenum portion of the piston / sleeve type control valve when the valve body moves when the servo pressure supply path is cut off when the servo pressure supply path is shut off A configuration having release means is employed. The second means is provided in the gap between the piston and the sleeve, which is disposed on the valve body of the shut-off valve and is located between the high-pressure fluid supply port and the connection part of the servo pressure supply path, instead of the fluid release means in the first means. A configuration to which a fluid releasing means to be connected is added is adopted. A third means is to temporarily fix a piston-sleeve type control valve for controlling a flow path by moving a valve body by fluid pressure applied to a high-pressure plenum portion and a low-pressure plenum portion on both sides of a piston. In the case of a device, a shut-off valve interposed between two servo pressure supply paths sent to the piston-sleeve type control valve, and a working fluid which is connected to the shut-off valve and feeds the working fluid when the piston-sleeve type control valve is fixed. And a high-pressure fluid supply means for shutting off the servo pressure supply path with a connection passage for connecting the two servo pressure supply paths to the valve body of the shutoff valve. However, the upstream side is set at a position shifted in the direction of the high pressure fluid supply port with respect to the downstream side, and the connection flow path is formed to have a larger width dimension than the shift of the connection portion, and the high pressure Fluid supply Sealing means for sealing between between and downstream thereon two servo pressure supply passage upon actuation of the stage employs a configuration in which is disposed. The fourth means adopts a configuration in which, in addition to the third means, a shutoff valve for isolating between the upper and lower streams of the two servo pressure supply paths is arranged on only one side.

[0008]

In the first means, when the piston-sleeve type control valve is temporarily fixed, high-pressure fluid is sent from the high-pressure fluid supply means to the shut-off valve to cut off the two servo pressure supply paths. Then, the supply of new servo pressure to the piston-sleeve type control valve is interrupted. At this time, the movement of the valve body of the shut-off valve connects the low-pressure plenum portion of the piston-sleeve type control valve to the fluid releasing means, thereby causing a change in the direction of the pressure applied to the seal portion of the control valve and the shut-off valve. The piston is kept in a stable state without causing the movement of the piston based on the volume constancy even when the pressure of the fluid fluctuates. In the second means, similarly to the first means, when the piston / sleeve type control valve is temporarily fixed, high-pressure fluid is sent to the shutoff valve to cut off the servo pressure supply path. In addition, the servo pressure supply is interrupted, but in addition, by moving the valve body of the shutoff valve, the pressure in the gap between the piston and the sleeve located between the high pressure fluid supply port and the connection part of the servo pressure supply path is reduced. The high-pressure fluid is guided to the fluid releasing means to suppress the occurrence of the piston movement phenomenon based on the volume invariance in the fluid in the pressurized state without causing a change in the direction of the pressure applied to each seal portion, When the fluid moves the shutoff valve, the impact pressure applied to the seal portion on the connection side of the high-pressure fluid supply means is suppressed. In the third means, the servo pressure supply is interrupted by the operation of the shutoff valve, as in the first means and the second means. By locating the means between the two servo pressure supply paths and between upstream and downstream thereof, the connection path and the two servo pressure supply paths downstream thereof are isolated from the high pressure fluid, and the two servo pressure supply fluids at the control valve are separated. To maintain equilibrium. According to the fourth means, although the operation is the same as that of the third means, with the movement of the valve element in the shutoff valve, the sealing means seals one of the two servo pressure supply paths between the upstream and downstream. To maintain the balance between the two servo pressure supply fluids at the control valve when the direction of the external force acting on the control valve is constant.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a piston-sleeve type control valve fixing device according to the present invention will be described below with reference to FIGS.

[First Embodiment] FIGS. 1 and 2 show a first embodiment of a fixing device for a piston-sleeve type control valve according to the present invention. (Control valve) 2 is a servo pressure generating means, 3A and 3B are servo pressure supply paths, 4 is a shutoff valve, 5 is a high pressure fluid supply means,
6 is a fluid release means, 7 is a fluid supply system, 8 is a fluid consumption system,
9 is a common casing and 10 is a case pressure setting means.

The control valve 1 has a high-pressure plenum portion 1c and a low-pressure plenum portion 1d connected to two servo pressure supply paths 3A and 3B on both sides of a piston 1b housed inside a sleeve 1a. The opening of the flow path 1f is controlled by the movement of the valve 1e connected to the piston 1b.
Is constrained. Further, the piston 1b and the valve element 1e
Are provided with seal rings 1g and 1h for sealing between the sleeve and the sleeve 1a.

The servo pressure generating means 2 applies two servo pressures to the high-pressure plenum 1c and the low-pressure plenum 1d of the control valve 1 with the shut-off valve 4 interposed in the middle of the servo pressure supply passages 3A and 3B. In addition, the opening of the control valve 1 is adjusted.

The shut-off valve 4 includes a sleeve 4a, a piston 4b housed inside the sleeve 4a, a solenoid valve 5
B, a high-pressure fluid supply port 4c for driving the piston 4b, a valve element 4d integrally connected to the piston 4b for connecting or disconnecting the servo pressure supply paths 3A and 3B,
The valve body 4d is returned by the elastic force and the servo pressure supply paths 3A, 3
A spring 4e for connecting to B, and a valve body 4d
And a plurality of seal rings 4f, 4g, 4h, 4i which are arranged on the outer periphery of the sleeve 4a and seal between the sleeve 4a.

The high-pressure fluid supply means 5 is disposed between the high-pressure fluid generation means 5A and the high-pressure fluid supply port 4c of the shut-off valve 4, and is used to shut off the working fluid when fixed. 4 for shutting off the servo pressure supply passages 3A and 3B.

The fluid releasing means 6 includes a valve body 4 of the shut-off valve 4.
The opening 6a is connected to the gap between the sleeve 4a and the valve body 4d, and the opening 6a is formed at a position between the seal rings 4g and 4h. At the same time, the servo pressure supply path 3A by the shutoff valve 4
At the time of shutoff of 3B, as shown in FIG. 2, the control valve 1 is set to be connected to the low-pressure plenum portion 1d.

The fluid supply system 7 supplies a desired fluid to the fluid consumption system 8, and the flow rate is adjusted and controlled by the control valve 1 provided in the middle of the supply path.

In the example shown in FIG. 1, the common casing 9 houses the control valve 1 and the shut-off valve 4, respectively.

The case pressure setting means 10 is connected to the surplus fluid storing portion 10a such as the shut-off valve 4 and the like in the common casing 9 and the solenoid valve 5B, and sets the fluid pressure discharged from these to a relatively low pressure constant value. Things.

A method of fixing the control valve 1 by the control valve fixing device having such a configuration will be described below.

In the steady state, as shown in FIG.
When the solenoid valve 5B is closed, the high-pressure fluid generating means 5A
And the high-pressure fluid supply port 4c is shut off, and the shut-off valve 4 connects the servo pressure generating means 2 to the control valve 1 so that the servo pressure passes through the servo pressure supply paths 3A and 3B. By applying to the high-pressure plenum 1c and the low-pressure plenum 1d, the position of the piston 1b is controlled, and the opening of the flow path 1f is set based on the amount of movement of the valve 1e.

In this steady state, the seal rings 1g, 1h,
Looking at the direction of the pressure applied to 4f, 4g, 4h, 4i,
Based on the relationship of the pressure of the flow path 1f> the pressure of the servo pressure supply path 3A> the pressure of the servo pressure supply path 3B> the case pressure, as shown by a solid line arrow in FIG.
h, 1g, 4g, and 4i, a left-facing state, and seal rings 4f and 4h, a right-facing state. Therefore, each seal ring 1g, 1h, 4f, 4g, 4h, 4
i will be compressed in the direction of these pressures.

On the other hand, when the control valve 1 is temporarily fixed while the opening of the flow path 1f is set by the control valve 1, the solenoid valve 5B of the high-pressure fluid supply means 5 is opened. Then, the high-pressure fluid is sent from the high-pressure fluid supply port 4c into the inside of the sleeve 4a, thereby moving the piston 4b and the valve body 4d to the left in FIG. 1 to the state shown in FIG. That is, the valve element 4d is connected to the two servo pressure supply paths 3A,
By moving to the shut-off position of 3B, the servo pressure supply paths 3A and 3B downstream of the shut-off valve 4 are isolated.
The supply of the new servo pressure to the control valve 1 is interrupted, and the fluctuation of the servo pressure is suppressed.

In the state shown in FIG. 2, the high-pressure plenum 1c and the low-pressure plenum 1d in the control valve 1 are separated from the servo pressure generating means 2, so that no new servo pressure is supplied and fluid is not supplied. , The piston 1b and the valve element 1e are fixed at positions corresponding to the servo pressure just before the operation of the shut-off valve 4.

The seal rings 1g, 1h, 4f, 4g, 4h, 4i of the valve bodies 1e, 4d in this fixed state.
Looking at the direction of the pressure applied to the opening,
Since a is connected to the servo pressure supply path 3B downstream of the high pressure fluid, the high pressure fluid is supplied from the high pressure fluid supply port 4c at the seal ring 4f. As shown in the figure, the pressure relationship is leftward, but the other portions have the above-described pressure relationship.

In this case, the direction of the pressure applied to the portion of the seal ring 4f is different from the direction of the solid line arrow in FIG. 1, but at the moment when the high-pressure fluid is supplied to the high-pressure fluid supply port 4c, FIG.
Then, the seal ring 4f is compressed in the direction shown by the broken line arrow, and after the balance with the servo pressure supplied from the servo pressure supply path 3A is performed, the valve body 4d of the shut-off valve 4 is set.
, The servo pressure supply path 3A at the downstream position is isolated. Therefore, even if the seal ring 4f is used, the pressure direction does not change when the servo pressure supply path 3A is isolated just before and after the servo pressure supply path 3A is isolated, and the movement restriction state of the valve element 1e continues thereafter. .

Next, when releasing the fixed state,
When the supply of the high-pressure fluid from the high-pressure fluid generating means 5A is stopped by the solenoid valve 5B, the internal fluid in the high-pressure fluid supply port 4c is sent to the case pressure setting means 10, and the operating pressure in the shut-off valve 4 disappears, and the spring The valve element 4d is returned to the state shown in FIG. 1 by the elastic force of 4e, and the flow rate is again controlled by the servo pressure.

[Second Embodiment] FIGS. 3 and 4 show a piston-sleeve type control valve fixing device according to a second embodiment of the present invention.

The second embodiment has many parts common to the first embodiment shown in FIGS. 1 and 2, except that a plurality of openings 6a in the fluid releasing means 6 are provided.
The formation positions are in the vicinity of the seal ring 4f and shifted in the direction of the high-pressure fluid supply port 4c, and the seal rings 4g, 4h
Is set to a position between

Even in the steady state shown in FIG. 3, when the servo pressure is applied to the high-pressure plenum 1c and the low-pressure plenum 1d, the position of the piston 1b is controlled, and the opening of the flow path 1f is set. You. In this case, each of the seal rings 1g, 1h, 4f, 4g, 4h, and 4i has the structure shown in FIG.
Are applied in the directions indicated by arrows, and the seal rings 1g, 1h, 4f, 4g, 4h, 4i are compressed in these directions.

Next, the solenoid valve 5B is opened, high-pressure fluid is fed into the sleeve 4a from the high-pressure fluid supply port 4c, and the valve body 4d is moved to the left in FIG. When the servo pressure supply passages 3A and 3B are shut off as described above, the high-pressure fluid sent into the sleeve 4a passes through the opening 6a from the annular gap located between the piston 4b and the high-pressure fluid supply port 4c. Then, the fluid is discharged outside the shut-off valve 4 (outside the common casing 9) by the fluid releasing means 6.

The servo pressure supply path 3A downstream of the shut-off valve 4
In the internal fluid, the opening 6a is arranged at a position shifted to the side of the high-pressure fluid supply port 4c from the servo pressure supply path 3A, and pressure fluctuation occurs due to the high-pressure fluid flowing into the opening 6a. Is suppressed.

Therefore, as shown by each arrow in FIG.
The direction of the pressure applied to each seal ring 1g, 1h, 4f, 4g, 4h, 4i does not change compared to FIG. 3, in other words, each seal ring 1g, 1h, 4f,
The direction of the pressure applied to 4g, 4h, 4i is constant regardless of whether or not the shut-off valve 4 is operated.

In FIG. 4, a low-pressure plenum 1d located on the left side of the piston 1b of the control valve 1 and the servo pressure supply path 3
B has a completely sealed state without deformation of the seal rings 1g, 4h, 4i, and therefore, in the second embodiment, similarly to the first embodiment, based on the incompressibility of the fluid. , The piston 1b and the valve element 1e maintain a fixed state at a position corresponding to the servo pressure immediately before the operation of the shut-off valve 4.

[Third Embodiment] FIGS. 5 and 6 show a third embodiment of the piston-sleeve type control valve fixing device according to the present invention.

In the third embodiment, as shown in FIG. 5 and FIG.
Connection flow paths 4j and 4k for connecting A and 3B are formed, and the fluid release means 6 and the opening 6a are omitted as compared with the examples of FIGS.

The connection openings of the servo pressure supply paths 3A and 3B are
The upstream side is set at a position shifted in the direction of the high-pressure fluid supply port 4c with respect to the downstream side, and correspondingly,
As shown in FIG. 5, the connection flow paths 4j and 4k are formed in an annular shape having a width larger than the displacement dimension of the connection part between the servo pressure supply paths 3A and 3B.

In the steady state shown in FIG. 5, when the servo pressure is applied to the high-pressure plenum 1c and the low-pressure plenum 1d, the position of the piston 1b is controlled and the flow path 1
The opening of f is set. In this case, the seal rings 1g, 1h, 4f, 4g, 4h, 4i are pressed in the directions indicated by the arrows based on the above-mentioned pressure difference.

Next, when the high-pressure fluid is sent from the high-pressure fluid supply port 4c to the inside of the sleeve 4a, and the valve element 4d is moved in the direction of the high-pressure fluid supply port 4c, as shown in FIG.
When the servo pressure supply paths 3A, 3B are cut off by the seal rings 4f, 4g, 4h, 4i, the seal rings 1g, 1h, 4f, 4g, 4h, 4i are pressed in the directions indicated by the arrows in FIG. Can be

Comparing the arrows in FIG. 5 and FIG. 6, only the seal ring 4f changes the direction. But,
As shown in FIG. 6, the connection flow path 4j and the servo pressure supply path 3
A, the high pressure plenum 1c and the connection flow path 4k, the servo pressure supply path 3B, and the low pressure plenum 1d are formed of seal rings 4f and 4d.
g, 4h, and 4i, the volume of the sealed fluid does not change based on the incompressibility of the fluid as in the first and second embodiments because the volume of the sealed fluid does not change. , The piston 1b and the valve element 1e maintain a fixed state at a position corresponding to the servo pressure immediately before the operation of the shut-off valve 4.

Fourth Embodiment FIGS. 7 and 8 show a fourth embodiment of a fixing device for a piston-sleeve type control valve according to the present invention.

In the fourth embodiment, the servo pressure supply path 3B and its shut-off means are omitted, and only the servo pressure supply path 3A is opened and shut off, as compared with the examples of FIGS. Like that.

When the pressure of the high-pressure fluid supplied from the high-pressure fluid supply port 4c is lower than or equal to the internal pressure of the servo pressure supply path 3A, the pressure of the servo pressure supply path 3A upstream of the shut-off valve 4 is increased. When the volume is large, when the volume of the servo pressure supply path 3A downstream of the shut-off valve 4 is large and the deformation of the seal ring 4f can be ignored, and when the deformation of the seal ring 4f is set to be extremely small, When two or more conditions are satisfied, the shut-off valve 4
Can be simplified.

In the steady state shown in FIG. 7, when a servo pressure is applied to the servo pressure supply path 3A, the seal rings 4f and 4g are pressed in the directions indicated by the double arrows based on the pressure difference.

Next, when the high-pressure fluid is fed into the inside of the sleeve 4a from the high-pressure fluid supply port 4c, the seal ring 4f is moved based on the above-described conditions together with the movement of the valve element 4d.
Are set as shown by the solid line or the broken line in FIG.

When the pressure in the direction indicated by the broken line in FIG. 8 is applied to the seal ring 4f, as described above, the connection fluid 4j, the servo pressure supply path 3A, and the internal fluid of the high pressure plenum portion 1c are removed. Based on the incompressibility, the fixed state of the control valve 1 is maintained. When the pressure in the direction indicated by the solid line arrow is applied to the seal ring 4f, the opening degree of the control valve 1 fluctuates by the volume change based on the deformation of the seal ring 4f, but can be ignored under the above-described conditions. Range, and a substantially fixed state is maintained.

[0046]

According to the piston-sleeve type control valve fixing device according to the first aspect, the following effects can be obtained. (1) A shut-off valve interposed between the two servo pressure supply paths, high-pressure fluid supply means connected to the shut-off valve to supply working fluid to shut off the servo pressure supply path, and a valve body of the shut-off valve. And a fluid releasing means connected to the low pressure plenum of the piston / sleeve type control valve, whereby high pressure fluid is sent to the shutoff valve to shut off the two servo pressure supply passages, thereby providing a new control valve to the control valve. By interrupting the supply of the two servo pressures, the control valve can be temporarily fixed, and the opening can be kept constant. (2) The connection between the low pressure plenum portion of the control valve and the fluid release means, without causing a change in the direction of the pressure applied to each seal portion, based on the volume constancy of the fluid,
The movement of the valve body of the control valve can be suppressed. (3) Since the shut-off valve is interposed between the two servo pressure supply paths, the structure is simplified and the piston and the sleeve are damaged as compared with the method of fixing the piston by mechanical means. Can be prevented. According to the piston-sleeve type control valve fixing device according to the second aspect, the following effects can be obtained. (1) By adopting a configuration in which a fluid releasing means connected to the gap between the piston and the sleeve is disposed on the valve body of the shut-off valve, the high-pressure fluid that has entered the gap between the piston and the sleeve is drawn when the piston is moved by the high-pressure fluid. Thus, the occurrence of the movement phenomenon of the seal portion can be suppressed, and the fixed state of the control valve can be reliably maintained. (2) When the high-pressure fluid enters the gap between the piston and the sleeve, the high-pressure fluid is discharged to reduce the impact pressure applied to the seal portion, thereby improving the overall safety. According to the piston-sleeve type control valve fixing device according to the third aspect, the following effects can be obtained. (1) The connection part of the servo pressure supply path on the upstream side is set at a position shifted in the direction of the high pressure fluid supply port with respect to the downstream side, and two servos are provided on both sides of the connection flow path when the high pressure fluid supply means is operated. By providing seal means for sealing between the pressure supply paths and between the upstream and downstream thereof, the servo pressure supply is interrupted by the operation of the shut-off valve, and the seal means separates the high pressure fluid from the connection flow path and the two downstream parts thereof. By isolating the servo pressure supply path, the two servo pressure supply fluids can be kept in an equilibrium state, and the control valve can be fixed for a long time. (2) The movement of the valve body of the control valve can be effectively suppressed based on the isolation of the servo pressure supply fluid separated from the high pressure fluid supply port and the volume invariance of the fluid in the isolated portion. According to the piston-sleeve type control valve fixing device of the fourth aspect, the following effects can be obtained. Claim 3
In addition, since the shut-off valve that isolates the upstream and downstream of the two servo pressure supply paths is arranged only on one side, the degree of the pressure of the high-pressure fluid and the volume of the servo pressure supply path are large. Under certain conditions, the effect on the sealing means can be reduced and the structure can be simplified.

[Brief description of the drawings]

FIG. 1 is a front sectional view in a steady state, together with a block diagram showing a first embodiment of a fixing device for a piston-sleeve type control valve according to the present invention.

FIG. 2 is a front sectional view, partially omitted, showing a situation in which a servo pressure supply path is shut off by a shut-off valve of FIG. 1;

FIG. 3 is a front sectional view showing a second embodiment of a fixing device for a piston-sleeve type control valve according to the present invention, in which a part of a steady state is omitted.

FIG. 4 is a front sectional view, partially omitted, showing a situation in which a servo pressure supply path is shut off by a shut-off valve in FIG. 3;

FIG. 5 is a front sectional view showing a third embodiment of a fixing device for a piston-sleeve type control valve according to the present invention, in which a part of a steady state is omitted.

FIG. 6 is a front sectional view, partially omitted, showing a situation in which a servo pressure supply path is shut off by the shut-off valve in FIG. 5;

FIG. 7 is a front sectional view showing a fourth embodiment of a fixing device for a piston-sleeve type control valve according to the present invention, with a part of a steady state being omitted.

8 is a front sectional view, partially omitted, showing a situation in which the servo pressure supply path is shut off by the shut-off valve in FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piston-sleeve type control valve (control valve) 1a Sleeve 1b Piston 1c High-pressure plenum 1d Low-pressure plenum 1e Valve 1f Flow path 1g, 1h Seal ring 2 Servo pressure generating means 3A, 3B Servo pressure supply path 4 Shutoff valve 4a Sleeve 4b Piston 4c High-pressure fluid supply port 4d Valve 4e Spring 4f, 4g, 4h, 4i Seal ring 4j, 4k Connection flow path 5 High-pressure fluid supply means 5A High-pressure fluid generation means 5B Electromagnetic valve 6 Fluid release means 6a Opening 7 Fluid supply System 8 Fluid consumption system 9 Common casing 10 Case pressure setting means 10a Storage unit

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16K 31/12-31/42 F23R 3/28 F02C 9/26 F23N 1/00 F15B 13/044

Claims (4)

(57) [Claims] A valve body is moved by fluid pressure applied to a high pressure plenum portion and a low pressure plenum portion on both sides of a piston,
A device for temporarily fixing a piston / sleeve type control valve for controlling a flow path, a shutoff valve interposed in the middle of two servo pressure supply paths sent to the piston / sleeve type control valve, and , A piston connected to the shut-off valve
A high-pressure fluid supply means for feeding the working fluid to shut off the servo pressure supply path when the sleeve-type control valve is fixed, and a piston-sleeve type for displacing the valve body when the servo pressure supply path is cut off when the servo pressure supply path is shut off. Fluid release means connected to the low pressure plenum of the control valve. 2. A valve body is moved by fluid pressure applied to a high pressure plenum portion and a low pressure plenum portion on both sides of a piston,
A device for temporarily fixing a piston / sleeve type control valve for controlling a flow path, a shutoff valve interposed in the middle of two servo pressure supply paths sent to the piston / sleeve type control valve, and , A piston connected to the shut-off valve
A high-pressure fluid supply means for supplying a working fluid to shut off the servo pressure supply path when the sleeve-type control valve is fixed, and between a high-pressure fluid supply port disposed on a valve body of the shutoff valve and a connection portion of the servo pressure supply path. And a fluid release means connected to the gap between the piston and the sleeve located therein. 3. A valve body is moved by fluid pressure applied to a high pressure plenum portion and a low pressure plenum portion on both sides of a piston,
A device for temporarily fixing a piston / sleeve type control valve for controlling a flow path, a shutoff valve interposed in the middle of two servo pressure supply paths sent to the piston / sleeve type control valve, and , A piston connected to the shut-off valve
High pressure fluid supply means for supplying a working fluid to shut off the servo pressure supply path when the sleeve type control valve is fixed, and a connection flow path for connecting the two servo pressure supply paths to the valve body of the cutoff valve Is formed, the connection part of the servo pressure supply path is set at a position where the upstream side is shifted in the direction of the high pressure fluid supply port with respect to the downstream side, and the connection flow path is formed with a width dimension larger than the deviation of the connection part. A piston-sleeve type control valve, wherein seal means for sealing between the two servo pressure supply paths and upstream and downstream thereof when the high-pressure fluid supply means is operated are disposed on both sides of the connection flow path. Fixing device. 4. The piston-sleeve type control valve fixing device according to claim 3, wherein a shut-off valve for isolating between the upstream and downstream of the two servo pressure supply paths is provided only on one side.