JP2001059501A - Fluid pressure intensifying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance responsiveness to stroke changeover, reduce a radial size for compactness and relax accuracy need in working parts. SOLUTION: A pressure intensifier 3 and a control valve mechanism 4 are provided inside a main case 2, a changeover of an oil passage is carried out by the control valve mechanism 4 thereby successively actuating the pressure intensifier 3, and a primary pressure supplied from a primary port 6 is intensified by the pressure intensifier 3 to be discharged into a secondary port 8. The pressure intensifier 3 and the control valve mechanism 4 are serially arranged, and a movement of a piston 10a is directly transmitted to the control valve mechanism 4 via a spool 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure intensifying device which can be operated continuously, and more particularly to a device having an improved arrangement and structure of a control valve mechanism.

[0002]

2. Description of the Related Art Continuously operable fluid pressure intensifiers include:
A pressure intensifier for increasing the secondary pressure to generate a secondary pressure, and a control valve mechanism for switching a fluid passage so as to continuously operate the pressure intensifier are provided. The pressure intensifier has a piston that receives a primary pressure and a plunger that is driven by the piston to generate a secondary pressure. In this pressure-intensifying device, a plurality of fluid passages are switched by a control valve mechanism, and the piston and the plunger are reciprocated integrally, whereby the pressure-increasing stroke and the return stroke are continuously performed at a high speed.

In the return stroke, while the pressure receiving chamber is in communication with the tank port, the piston is returned to the return limit position while filling the pressure boosting chamber with the primary pressure. When the secondary pressure is charged, the piston receives the primary pressure in the pressure receiving chamber, drives the plunger, and pressurizes the fluid in the pressure increasing chamber to generate a secondary pressure higher than the primary pressure.

Conventionally, various control valve mechanisms have been applied. In the pressure booster described in U.S. Pat. No. 5,170,691, a pilot switching valve is used as a control valve mechanism. This pilot type switching valve includes a cylindrical first movable body (sleeve) movably mounted in a cylinder hole in a main body case, and a pipe-shaped shaft member internally fitted to the first movable body so as to be relatively movable. A second movable body (spool), a friction ring mounted between the first and second movable bodies, a coil spring for urging the first movable body so that the switching valve is in a communicating position, and a plunger hole of the pressure intensifier. It has a pilot pressure introduction passage for introducing fluid pressure as pilot pressure of the switching valve.

In this pressure-increasing device, during the pressure-increasing stroke, the switching valve is held at the supply position and the pressure-receiving chamber is filled with the primary pressure while the low-pressure chamber between the piston and the plunger communicates with the tank to increase the pressure. Do. At the time of the return stroke, the switching valve is held in the communicating position to communicate the pressure receiving chamber and the low pressure chamber, and the piston and the plunger are returned by the primary pressure filled in the pressure increasing chamber.

[0006]

In the pressure booster described in the above publication, the piston is not directly mechanically connected to the spool or the sleeve, but is indirectly connected via a pilot pressure introduced from a pilot pressure introduction passage. It is a structure connected to. Therefore, it is difficult to increase the responsiveness of the switching valve that operates in conjunction with the piston, and it is difficult to increase the pressure increasing performance. That is, since the pilot pressure introduction path is long and the amount of fluid inside the pilot pressure introduction path is large, there is a limit in improving the responsiveness of switching of the switching valve. Moreover, since the switching valve is switched to the communicating position by the elastic force of the coil spring, it is disadvantageous in operating at high speed, and the responsiveness and durability of the switching valve may be reduced due to deterioration of the coil spring. In addition, since the number of parts of the switching valve is large and the structure is complicated, the manufacturing cost is high.

In order to shorten the pilot pressure introduction path as much as possible,
In the actual product, the switching valve is arranged in a parallel position in parallel with the side portion of the pressure intensifier. In this case, the size of the pressure intensifier device in the radial direction becomes large, which is disadvantageous in various aspects such as manufacturing cost, handling, and attachment to an external device. An object of the present invention is to provide a fluid pressure intensifier having a control valve having excellent switching response, to provide a fluid pressure intensifier capable of being miniaturized in the radial direction, and to improve the precision of component processing. And to provide an advantageous fluid pressure intensifier.

[0008]

According to a first aspect of the present invention, there is provided a fluid pressure increasing device, comprising: a main body case; a piston provided in the main body case and receiving a primary pressure; and a secondary pressure driven by the piston. An intensifier having a plunger to generate;
A control valve mechanism for switching a fluid passage so as to continuously operate the pressure intensifier, wherein the control valve mechanism is connected to a piston of the pressure intensifier and extends to a side opposite to a plunger. And a sleeve having a spool hole into which the spool can be slidably inserted, and a valve accommodation hole formed in the main body case so that the sleeve can move by a predetermined stroke. The connection between the piston and the spool may be an integral connection, but is preferably a connection that can be disconnected.

As described above, since the spool is connected to the piston and extends to the side opposite to the plunger, the movement of the piston can be directly transmitted to the control valve mechanism via the spool, thereby improving the responsiveness of the control valve mechanism. ,
The operating speed can be increased to increase the pressure increasing performance of the fluid pressure increasing device. In addition, since the pressure intensifier and the control valve mechanism are arranged in series, the thickness (radial size) of the control valve mechanism can be reduced and a compact structure can be achieved. This is advantageous in terms of attachment to an external device.

According to a second aspect of the present invention, in the first aspect of the invention, the spool is formed separately from the piston and has an engaging portion at a base end on the piston side, and the piston is provided with a spool. Characterized by having an engaging groove for integrally and movably engaging the engaging portion in the axial direction. Since the piston slides in the cylinder hole in a fluid-tight manner and the spool slides in the spool hole of the sleeve almost in a fluid-tight manner, precision requirements for manufacturing the spool and the piston are very severe. However, since the spool is formed separately from the piston, and the engagement portion of the spool is engaged with the engagement groove of the piston to connect the two, the accuracy requirement when manufacturing the spool and the piston is remarkably relaxed. In addition to being advantageous in terms of manufacturing, it is not easily unevenly worn and durability is improved.

A third aspect of the present invention is the fluid pressure intensifying device according to the first or second aspect, further comprising an urging mechanism for receiving the primary pressure and urging the sleeve toward the piston. Is what you do. When the spool is urged by the spring member, the responsiveness and durability are likely to decrease due to the deterioration (set) of the spring member. However, since the urging is performed by receiving the primary pressure, the responsiveness and the responsiveness are reduced. This is advantageous in ensuring durability.

According to a fourth aspect of the present invention, in the fluid pressure intensifying device according to the third aspect of the present invention, a stroke switching annular groove is formed on an outer peripheral portion of the sleeve, and the pressure switching process is performed via the stroke switching annular groove. Is characterized in that a primary pressure is supplied to a pressure receiving chamber for receiving a pressure by a piston, and a fluid in the pressure receiving chamber is discharged to a tank port in a return stroke. Since the stroke switching annular groove moves together with the sleeve, the stroke can be switched from the return stroke to the pressure increasing stroke and vice versa by moving the sleeve in conjunction with the piston and the sleeve.

According to a fifth aspect of the present invention, in the fluid pressure intensifying device according to the fourth aspect, a sleeve pressure receiving chamber for receiving pressure by the sleeve is formed in a portion of the valve receiving hole closer to the piston than the sleeve and on the outer peripheral side of the spool. An annular groove is formed on the outer peripheral portion of the sleeve, and the primary pressure is supplied to the sleeve pressure receiving chamber through the annular groove at the start of the pressure increase process. Since the annular groove formed in the outer peripheral portion of the spool moves together with the spool, the annular groove can be moved in conjunction with the piston and the spool, and the primary pressure is supplied to the sleeve pressure receiving chamber in conjunction with the piston and the spool. be able to.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment is an example in which the present invention is applied to a hydraulic pressure booster that increases the hydraulic pressure. As shown in FIGS. 1 to 3, a hydraulic pressure intensifier 1 includes a main body case 2 and a pressure intensifier 3 provided in the main body case 2.
And a control valve mechanism 4 for switching a hydraulic passage so as to continuously operate the pressure intensifier 3.
And a control valve mechanism 4 provided therein.

The main body case 2 comprises a block 2a having a square cross section and blocks 2b to 2d having a circular cross section. These blocks 2a to 2d are arranged in series and integrally connected by two through bolts 5. ing. A primary pressure is supplied to the right end of the main body case 2 from a hydraulic pump.
A next port 6 and a tank port 7 connected to the tank are formed, and a secondary port 8 for discharging a secondary pressure is formed at the left end of the main body case 2. In addition, the blocks 2a to 2
An O-ring 9 is mounted between d.

The pressure intensifier 3 includes a piston member 10 integrally formed with a piston 10a and a plunger 10b,
It includes a cylinder hole 11, a plunger hole 12, a suction check valve 13, a discharge check valve 14, a check valve mechanism 15 for releasing secondary pressure, and the like. Piston 10a
Is formed much larger in diameter than the plunger 10b. The cylinder hole 11 is formed in the block 2b in a penetrating manner, and the plunger hole 12 is formed concentrically with the cylinder hole 11 so as to communicate with the cylinder hole 11. The piston 10a is slidably mounted in the cylinder hole 11. A pressure receiving chamber 16 is formed in the cylinder hole 11 on the right side of the piston 10a, and the low pressure chamber 1 is on the left side of the piston 10a.
7 are formed. A plurality of labyrinth seal grooves 19 forming a labyrinth seal are provided on the outer peripheral portion of the piston 10a.
Are formed.

The plunger 10b is slidably mounted in the plunger hole 12, and a pressure increasing chamber 18 is formed in the plunger hole 12 on the left side of the plunger 10b.
A discharge check valve 14 is provided between the secondary port 8 and the secondary port 8. A plurality of labyrinth seal grooves 20 forming a labyrinth seal are formed on the outer peripheral portion of the plunger 10b. The blocks 2 a to 2 d are formed with a straight oil passage 21 communicating with the primary port 6 and a straight oil passage 22 communicating with the tank port 7. The pressure receiving chamber 16 is connected to the oil passage 21 via the oil passage 23, the control valve 4, and the oil passage 24. The low pressure chamber 17 is connected to the oil passage 22 via an oil passage 25. The booster chamber 18 is
6, the check valve 13 and the oil passage 27 are connected to the oil passage 21. The pressure increasing chamber 18 is provided with an oil passage 28 and the check valve 14.
Is connected to the secondary port 8 (discharge port) via the

The check valve mechanism 15 is a mechanism for releasing the secondary pressure, and is not essential for the hydraulic pressure increasing device 1. The check valve mechanism 15 includes the check valve 3
0, the piston member 3 for opening the check valve 30
1 and a cylinder hole 32 in which the piston member 31 is slidably mounted. The check valve 30 shuts off an oil passage 33 leading to the secondary port 8, and the piston member 31 Pressure is being received. When the secondary pressure is released by the check valve mechanism 15, the primary pressure is supplied to the tank port 7, and when the check valve 30 is opened by the piston member 31, the secondary port 8 and the oil passage 33 are opened. The incoming high pressure oil passes through the check valve 30 and passes through the oil passage 3
4 flows into the oil passages 27 and 21 and is opened to the primary port 6.

Next, the control valve mechanism 4 will be described. The control valve mechanism 4 includes a valve housing chamber 40,
A spool 41 connected to the piston 10a, a sleeve 42 slidably mounted in the valve receiving hole 40, a biasing mechanism 43 for biasing the sleeve 42 to the left, and a plurality of oil passages are provided. . The valve receiving hole 40 is formed concentrically with the cylinder hole 11 in the block 2c, and the block 2c is also formed with a spool insertion hole 44 that is continuous with the cylinder hole 11 and the valve receiving hole 40. The spool 41 has a spool insertion hole 44.
Is slidably inserted into the spool hole 42a of the sleeve 42.
Is slidably inserted into

An engagement portion 41a formed through a pair of grooves is formed at a base end (left end) on the piston side of the spool 41. The engaging portion 41a is detachably connected to the engaging groove 10c at the right end of the piston 10a, and the spool 41 and the piston 10a are connected so as to move integrally in the axial direction. However, the engaging portion 41a and the engaging groove portion 10c have a spool 4 with respect to the piston 10a.
There is a slight gap that allows 1 to be relatively movable. An annular sleeve pressure receiving chamber 40a is formed on the left side portion (piston side portion) of the valve receiving hole 40 with respect to the sleeve 42 and on the outer peripheral side of the spool 41, and the volume of the sleeve pressure receiving chamber 40a changes according to the movement of the sleeve 42. . The sleeve introduction chamber 40b on the right side of the sleeve 42 in the valve accommodation hole 40
Is connected to the oil passage 22 by an oil passage 45, and the spool hole 42
a spool introduction chamber 42b on the right side of the spool 41 in FIG.
Communicates with the sleeve introduction chamber 40b (see FIG. 7).

The spool 41 has an annular groove 46 formed therein.
The primary pressure of the oil passage 21 can be supplied to the sleeve pressure receiving chamber 40a via the oil passage 47 and the annular groove 46. Sleeve 4
An annular groove 48 for switching a stroke is formed in an outer peripheral portion at a substantially central portion in the left-right direction. In the pressure increasing stroke in which the piston member 10 moves to the left, the primary pressure of the oil passage 21 is supplied to the pressure receiving chamber 16 via the oil passage 24, the annular groove 48, and the oil passage 23, and the piston member 10 In the return stroke moving rightward, the oil in the pressure receiving chamber 16 is filled with the oil passage 23 and the annular groove 4.
The oil is discharged to the oil passage 22 via the oil passage 8 and the oil passage 49. Further, a shallow annular groove 49 a communicating with the oil passage 49 is formed in the peripheral surface of the valve housing hole 40.

The urging mechanism 43 is a mechanism that receives the primary pressure and urges the sleeve 42 leftward. The urging mechanism 43 is a small-diameter cylinder hole 5 formed in the block 2d.
0, and a piston member 51 movably mounted in the cylinder hole 50. A groove 52 smaller than the diameter of the piston member 51 is formed on the right end surface of the sleeve 42, and the piston member 51 is in contact with the right end surface of the sleeve 42. The piston member 51 receives the primary pressure introduced into the right end portion of the cylinder hole 50 from the oil passage 21 via the oil passage 53 and is urged to the left by receiving the primary pressure, and applies the urging force to the sleeve 42. In addition, only the main ones among many oil paths are illustrated and described, and some of the oil paths are not illustrated and the description is also omitted.

Next, the operation of the hydraulic pressure booster 1 will be described with reference to FIG.
This will be described with reference to FIG. When the hydraulic pressure is increased by the hydraulic pressure increasing device 1, the primary pressure discharged from the hydraulic pump is supplied to the primary port 6, the tank port 7 is connected to the oil tank, and the secondary port 8 is connected to the actuator. Increase the pressure while connected. 4 to 9, coarse dots as shown in the primary port 6 and the oil passage 21 indicate primary pressure oil, and fine dots as shown in the secondary port 8 indicate secondary pressure oil. , Coarse dots with oblique lines as shown in the tank port 7 and the oil passage 22 indicate drain pressure oil.

FIG. 4 shows a bottom dead center state in which the piston member 10 has returned to the maximum. In the bottom dead center state, the pressure increasing chamber 18 is filled with the primary pressure,
Communicates with both the oil passage 47 and the sleeve pressure receiving chamber 40 a, the stroke switching annular groove 48 communicates with the oil passage 23, and the annular groove 48 starts communicating with the oil passage 24. When the sleeve 42 is moved rightward by receiving the primary pressure of the sleeve pressure receiving chamber 40a and the annular groove 48 communicates with the oil passage 23 as shown in FIG. 5, the oil passages 21 and 24, the annular groove 48, the oil The primary pressure is supplied to the pressure receiving chamber 16 and the piston member 10
Is a pressure increasing stroke that moves to the left.

Thus, during the pressure increase stroke, the pressure receiving chamber 16
, The primary pressure in the pressure-intensifying chamber 18 is compressed by the plunger 10b to become a secondary pressure that is much higher than the primary pressure. (See FIGS. 5 and 6). During this pressure increase stroke, the sleeve 42 is urged leftward by the urging mechanism 43, but the rightward urging force by the primary pressure of the sleeve pressure receiving chamber 40a is large, so that the sleeve 42 is moved rightward. Move. At the end of the pressure increase stroke shown in FIG. 6, the sleeve 42 moves to the right as much as possible, and the distance between the left end of the sleeve 42 and the annular groove 49a decreases. Therefore, the amount of leakage from the sleeve pressure receiving chamber 40a to the annular groove 49a increases, and the oil pressure in the sleeve pressure receiving chamber 40a substantially decreases to the drain pressure. As a result, the sleeve 42 is
Start moving to the left with a bias of 3.

As shown in FIG. 7, when the piston member 10 moves to the left as much as possible to reach the top dead center state, the spool introduction chamber 42b and the sleeve pressure receiving chamber 40a substantially communicate with each other, and together with the sleeve 42, move to the left. The moving annular groove 48 is
And the oil passage 49 begin to communicate. As a result, the pressure receiving chamber 16 is communicated with the oil passage 22 by the oil pressure 23, the annular groove 48, and the oil passage 49. Thus, when the operation is switched to the return stroke, the pressure intensifying chamber 18
Is supplied with the primary pressure through the check valve 13,
The primary pressure in the pressure receiving chamber 16 is discharged to the oil passage 22, and the piston member 10 returns and moves.

As shown in FIG. 8, during the return stroke, the sleeve 42 moves to the left as much as possible. As shown in FIG. 9, at the final stage of the return stroke, the annular groove 46 is
7 starts to communicate with the sleeve pressure receiving chamber 40a, the annular groove 48 starts to separate from the oil passage 49, and immediately after that, the state is switched to the bottom dead center state in FIG. 4 to 9 are continuously performed at a high speed (for example, 3000 times per minute), and a high secondary pressure (for example, 30 to 60 MPa) is almost continuously discharged from the secondary port 8. You.

The hydraulic pressure booster 1 described above has the following effects. First, it is possible to enhance the responsiveness of switching the stroke of the control valve mechanism 4 and enhance the durability.
That is, since the spool 41 is connected to the piston 10a and extends to the side opposite to the plunger 10b to directly transmit the movement of the piston 10a to the control valve mechanism 4, the responsiveness of the stroke switching can be significantly improved.
The primary pressure introduced into the sleeve pressure receiving chamber 40a is equivalent to a pilot pressure for switching the control valve mechanism 4. An oil passage for introducing the pilot pressure from the oil passage 21 to the sleeve pressure receiving chamber 40a, Since the length of the oil passage for discharging the pressure from the sleeve pressure receiving chamber 40a to the spool introduction chamber 42b is configured to be extremely short, the responsiveness of switching the stroke from the return stroke to the pressure increase stroke and vice versa is remarkably improved. be able to. As a result, the hydraulic pressure intensifier 1 can operate at a higher speed, and the pressure intensifying performance of the hydraulic pressure intensifier 1 can be significantly improved.

Second, since the urging mechanism 43 for urging the sleeve 42 by receiving the primary pressure instead of urging the sleeve 42 with a spring member is provided, there is a concern that the spring member may be deteriorated (set). Therefore, the durability of the control valve mechanism 4 can be increased. The control valve mechanism 4 has a simple structure including a small number of components such as a valve housing hole 40, a spool 41, a sleeve 42, and a biasing mechanism 43, except for a plurality of oil passages. Third, the spool 42 is connected to the piston 1
0a and extended to the opposite side of the plunger 10b, and the pressure intensifier 3 and the control valve mechanism 4 were arranged in series, so that the hydraulic pressure intensifier 1 could have an elongated and compact structure. Therefore, the thickness (radial size) of the hydraulic pressure intensifier 1 is not increased, which is advantageous in terms of production, handling, attachment to an external device, and the like.

Fourth, the piston 10a and the spool 41 are separately formed, and the engaging portion 41a of the spool 41 is removably connected to the engaging groove 10c of the piston 10a, and is engaged with the engaging portion 41a. Since the groove 10c has a small gap that allows the spool 41 to slightly move with respect to the piston 10a, the piston 10a and the spool 41 are smaller than when the piston 10a and the spool 41 are integrally formed. The precision in machining the valve housing hole 40, the sleeve 42, and the spool hole 42a is not strict, so that the manufacture is easy, and they are less likely to be unevenly worn, and the durability is increased.

Next, an example of partially changing the hydraulic pressure increasing device 1 will be described. The structure of the main body case 2 is not limited to the structure of the above-described embodiment, and may be configured by three or less blocks instead of the four four blocks 2a to 2d. Further, the control valve mechanism 4 may have a smaller diameter. In addition, a seal member may be attached to the piston 10a in addition to the rabbititerinse seal mechanism, and a seal member may be attached to the plunger 10b in addition to the rabbititerinse seal mechanism. Further, the sleeve 42 and the piston member 51 may be integrally connected. Further, the present invention can be similarly applied to a pressure increasing device that increases various hydraulic pressures other than the hydraulic pressure. Others
It goes without saying that the present invention can be implemented in a form in which various changes are added without departing from the spirit of the present invention.

[0032]

According to the fluid pressure increasing device of the first aspect, the spool is connected to the piston and extends to the side opposite to the plunger, so that the movement of the piston is transmitted to the control valve mechanism via the spool. Since the direct transmission is possible, the responsiveness of the control valve mechanism can be enhanced, and the pressure increasing performance of the fluid pressure increasing device can be enhanced. Moreover, since the pressure intensifier and the control valve mechanism are arranged in series, the thickness (radial size) of the control valve mechanism is reduced,
The structure can be made compact, which is advantageous in terms of manufacturing, handling, and mounting the pressure booster to external equipment.

According to the second aspect of the present invention, the spool is formed separately from the piston and has an engaging portion at the base end on the piston side. With an engagement groove that engages so that it can move integrally in one direction, the precision requirements when manufacturing pistons and spools are remarkably relaxed, which is advantageous in terms of manufacturing, is less prone to uneven wear, and improves durability I do. The other effects are the same as those of the first aspect. According to the fluid pressure intensifying device of the third aspect, since the urging mechanism that receives the primary pressure and urges the sleeve toward the piston is provided, compared with a case where the spool is urged by the spring member, This is advantageous in ensuring responsiveness and durability of the control valve mechanism. The other effects are the same as those of the first or second aspect.

According to the fluid pressure increasing device of the fourth aspect, the stroke switching annular groove is formed on the outer peripheral portion of the sleeve, and the piston receives the pressure through the stroke switching annular groove in the pressure increasing stroke. While supplying the primary pressure to the chamber, the fluid in the pressure receiving chamber is discharged to the tank port in the return stroke. Since the stroke switching annular groove moves together with the sleeve, the stroke can be switched from the return stroke to the pressure increasing stroke and vice versa by moving the sleeve in conjunction with the piston and the sleeve. The other effects are the same as those of the third aspect.

According to the fluid pressure increasing device of the fifth aspect, a sleeve pressure receiving chamber for receiving pressure by the sleeve is formed in a portion of the valve receiving hole closer to the piston than the sleeve and on the outer peripheral side of the spool.
An annular groove is formed in the outer peripheral portion of the spool, and the primary pressure is supplied to the sleeve pressure receiving chamber via the annular groove at the start of the pressure increasing stroke. Since the annular groove formed in the outer peripheral portion of the spool moves together with the spool, the annular groove can be moved in conjunction with the piston and the spool, and the primary pressure is supplied to the sleeve pressure receiving chamber in conjunction with the piston and the spool. be able to. The other effects are the same as those of the fourth aspect.

[Brief description of the drawings]

FIG. 1 is a sectional view of a hydraulic pressure booster according to an embodiment of the present invention.

FIG. 2 is a sectional view of the hydraulic pressure intensifier at a position different from that of FIG. 1;

FIG. 3 is a cross-sectional view of the hydraulic pressure booster at a position different from FIGS. 1 and 2;

FIG. 4 is an operation explanatory diagram in the case of a hydraulic pressure booster (bottom dead center state).

FIG. 5 is an explanatory diagram of an operation when the hydraulic pressure increasing device is in the middle of a pressure increasing stroke.

FIG. 6 is an operation explanatory diagram in the case of a hydraulic pressure booster (end of pressure boosting stroke).

FIG. 7 is an operation explanatory diagram in the case of a hydraulic pressure increasing device (top dead center state).

FIG. 8 is an operation explanatory diagram in the case of a hydraulic pressure increasing device (during the return stroke).

FIG. 9 is an operation explanatory diagram in the case of a hydraulic pressure increasing device (end of a return stroke).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic pressure booster 2 Main body case 3 Booster 4 Control valve mechanism 6 Primary port 7 Tank port 8 Secondary port 10 Piston member 10a Piston 10b Plunger 10c Engagement groove part 16 Pressure receiving chamber 40 Valve accommodation hole 40a Sleeve pressure chamber 41 Spool 41a engaging portion 42 sleeve 43 urging mechanism 46 annular groove 48 stroke switching annular groove

Claims (5)

[Claims] An intensifier having a main body case, a piston provided in the main body case and receiving a primary pressure, and a plunger driven by the piston to generate a secondary pressure, And a control valve mechanism for switching a fluid passage so as to be operated in a controlled manner. The control valve mechanism comprises: a spool connected to a piston of a pressure intensifier and extending to a side opposite to a plunger; and A fluid pressure booster comprising: a sleeve having a spool hole that can be slidably inserted; and a valve housing hole formed in the main body case such that the sleeve is movable by a predetermined stroke. 2. The spool is formed separately from the piston and has an engagement portion at a base end on the piston side. The piston is engaged with the engagement portion of the spool so as to be integrally movable in the axial direction. 2. An engaging groove portion for mating.
3. The fluid pressure intensifier according to claim 1. 3. The fluid pressure intensifier according to claim 1, further comprising an urging mechanism that receives the primary pressure and urges the sleeve toward the piston. 4. A process switching annular groove is formed in an outer peripheral portion of the sleeve, and a primary pressure is supplied to a pressure receiving chamber which is made to receive pressure by a piston in a pressure increasing stroke through the process switching annular groove. The fluid in the pressure receiving chamber is discharged to a tank port during the return stroke.
3. The fluid pressure intensifier according to claim 1. 5. A sleeve pressure receiving chamber for receiving pressure by the sleeve is formed at a portion of the valve receiving hole closer to the piston than the sleeve and at an outer peripheral side of the spool, and an annular groove is formed at an outer peripheral portion of the spool. 5. The fluid pressure booster according to claim 4, wherein a primary pressure is supplied to the sleeve pressure receiving chamber at the start of the pressure boosting stroke.