JP2002283991A - Spool valve device, and brake fluid pressure booster using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten axial length and reduce cost, in a spool valve capable of switching the position of a spool between a case of leading high-pressure working fluid to a control chamber through a two-stage throttle part and a case of leading it without passing through the throttle part. SOLUTION: A spool valve device 27 has a sleeve 47 having a supply port 47b communicating with a high pressure source and a spool 29 that is inserted into the sleeve 47 axially and slidably and is exposed to the control chamber 31 at its one end side. An outer peripheral groove 29a is formed on the outer periphery of the spool 29, a variable throttle is formed with a corner 29aa of the outer peripheral groove and an opening end 47ba of the supply port and fluid pressure in the control chamber 31 is adjusted, due to the displacement of the spool 29 in the axial direction of the sleeve 47. The sleeve 47 has a control chamber port 47f opening at the axially same position as that of the opening end of the supply port 47b, and a communicating passage 47g for communicating the control chamber port 47f with the control chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spool valve device incorporated in a brake hydraulic booster of a vehicle or the like.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Unexamined Patent Application Publication No.
As described in Japanese Patent Publication No. 3 (2003), a master cylinder that operates a master cylinder piston in response to brake pedal operation to generate a brake fluid pressure, an accumulator (high-pressure source) that supplies high pressure, and a brake pedal in response to brake pedal operation. It has a spool valve device that includes a spool that operates and uses the high pressure from the high pressure source to adjust the hydraulic pressure in the control room. The brake pedal is operated by applying the hydraulic pressure in the control room to the master cylinder piston as servo pressure. There is known a brake hydraulic booster that assists in braking.

[0003] In such a brake hydraulic booster, the spool valve device used in the brake hydraulic booster described in the above-mentioned publication is designed to operate in a normal manner when a high pressure supplied from an accumulator is introduced into a control room. When braking,
In order to reduce the noise introduced, high pressure is introduced into the control room through a two-stage throttle section, and during sudden braking operation, the control room pressure is rapidly increased to ensure high responsiveness of assisting force. Therefore, it is configured such that high pressure can be introduced into the control chamber without passing through the throttle section. Such a configuration will be described below with reference to FIGS. Here, FIG. 3A shows a non-operating state in which the control chamber pressure is low, and FIG. 3B shows a state in which the control chamber pressure is being increased.

[0004] As shown in FIG. 3, a conventional spool valve device has a cylinder hole 100 d of a master cylinder case 100.
A spool 102 is slidably inserted in an axial direction (a left-right direction in FIG. 3) into a sleeve 101 housed in a liquid-tight manner. The spool 102 is configured to be displaced in response to operation of a brake pedal (not shown). At the right end of the spool 102 in FIG.
And a return chamber 104 is exposed at the left end. The hydraulic pressure in the control room 103 is controlled by the servo port 10
It is provided as servo pressure via 0a to assist the brake pedal operation. The return chamber 104 is connected to the port 101
e, communicating with a reservoir (not shown) via the return port 100c.

[0005] A first outer circumferential groove 102a and a second outer circumferential groove 102b are provided on the outer periphery of the spool 102 in series in the axial direction at a slight distance from each other. Sleeve 1
01 is provided with a supply port 101b for introducing the high pressure supplied from the accumulator to the control chamber 103 via the port 100b, and the sleeve 101 is used to connect the control chamber 103 to the return chamber 104. Communication holes 101c and 101d are provided. Further, the sleeve 101 is provided with an inner peripheral groove 101a having a predetermined width in the axial direction on the inner peripheral surface thereof as shown in FIG. A sufficient clearance is secured between the inner peripheral surface of the inner peripheral groove 101a and the outer peripheral surface of the spool 102 so as not to form a throttle.

Here, when the spool 102 is located at the axial position shown in FIG. 3A, the open end of the supply port 101b is positioned at the corner 1 of the first outer peripheral groove 102a of the spool 102.
Since it is closed by 02aa, the high pressure from the accumulator is not introduced into the control room 103. The open end of the communication hole 101d is located at the corner 1 of the spool 102.
The control room 103 is in communication with the return room 104 because it is in communication with the return room 104 at the position 02c.
Therefore, at the spool position shown in FIG. 3A, the control chamber pressure is maintained at a low pressure.

When a normal brake operation is performed by operating a brake pedal (not shown) from the state shown in FIG.
In the figure, a force in the direction A is applied to the spool 102, and the spool 102 slides leftward to the position shown in FIG.
When the spool 102 slides to this position, the communication hole 10
The open end of 1d is closed by the corner 102c of the spool 102, and the communication between the control chamber 103 and the return chamber 104 is released. Also, the open end 101 of the supply port 101b
ba and the corner 10 of the first outer peripheral groove 102a of the spool 102
2aa, the first throttle portion is formed, and the second throttle portion is formed by the corner portion 101aa of the inner peripheral groove 101a of the sleeve 101 and the corner portion 102ba of the second outer peripheral groove 102b of the spool 102. At the same time, the high pressure from the accumulator is introduced into the control chamber 103 through the gap between the outer circumference of the spool 102 and the inner circumference of the sleeve 101 while passing through the two-stage throttle section, and the control chamber pressure is controlled. You. Here, the introduced hydraulic fluid is decompressed every time it passes through the throttle unit, but since it passes through the two-stage throttle unit, compared to the case where it passes through the one-stage throttle, 1
The differential pressure generated before and after the two throttles can be reduced. Therefore, it is possible to suppress the occurrence of cavitation when the hydraulic fluid passes through the throttle portion, and it is possible to reduce the introduction noise of the hydraulic fluid due to the occurrence of cavitation as much as possible.

During a sudden braking operation, a large force is momentarily applied to the spool 102 from the direction A in FIG. 3, and the spool 102 may move further to the left from the position shown in FIG. 3B. In this case, the two-stage throttle section described above disappears at the same time, and the high pressure from the accumulator is introduced into the control room 103 without passing through the throttle section. Therefore, during a sudden braking operation,
The speed at which the control room pressure is increased can be improved, and high responsiveness of the assisting force for operating the brake pedal can be ensured.

[0009]

However, in the conventional spool valve device, as described above, depending on the position of the spool, a case where high pressure is introduced into the control chamber through a two-stage throttle portion and a case where high pressure is introduced through the throttle portion. In order to make it possible to switch between the case where the high pressure is introduced into the control chamber and the case where the high pressure is introduced into the control chamber, it is necessary to form two outer grooves on the outer periphery of the spool and to form an inner groove on the inner periphery of the sleeve.

[0010] Accordingly, there has been a problem that the axial length of the sleeve and the spool is increased, and the processing cost of these is also increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. When introducing a high-pressure hydraulic fluid into a control chamber, there are two cases where a high-pressure hydraulic fluid is introduced through a two-stage throttle section depending on the position of a spool. It is a technical object of the present invention to provide an inexpensive spool valve device that can be switched between a case where the spool valve device is introduced without passing through a part and a case where the axial length can be reduced.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a sleeve having a supply port communicating with a high pressure source, an axially slidably inserted sleeve inside the sleeve, and an outer peripheral groove formed on the outer periphery. Having a spool formed thereon,
In a spool valve device in which a variable throttle is formed by a corner portion of an outer peripheral groove and an opening end of a supply port by axial displacement of a spool with respect to a sleeve and a hydraulic pressure in a control chamber is adjusted, a sleeve has a supply port A spool valve device is characterized in that a control chamber port that opens at the same position in the axial direction as the open end and a communication path that communicates the control chamber port with the control chamber are formed. Here, the “axial direction” refers to a sliding direction of the spool with respect to the sleeve.

According to the present invention, the sleeve has an opening end of the supply port communicating with the high-pressure source and an opening end of the control chamber port communicating with the control chamber through the communication passage at the same position in the axial direction. Since the variable aperture can be formed by these two open ends and the corners of the outer peripheral groove formed in the spool, the positions of the corners of the outer peripheral groove of the spool are close to these two open ends. If there is a spool at a position where the two are located, two narrow portions are formed by these two adjacent portions. Therefore, the working fluid supplied from the high pressure source passes through the supply port, is squeezed at the open end of the supply port, passes through the space formed by the outer peripheral groove of the spool and the inner peripheral surface of the sleeve, and then enters the control chamber After being squeezed again at the opening end of the port, it is introduced into the control room via the control room port and the communication passage. Therefore, when the corner of the outer peripheral groove of the spool is located at a position close to these two open ends, high pressure is introduced into the control chamber from the high-pressure source through the two-stage throttle unit. Therefore, as described above, the introduction sound of the working fluid can be reduced.

Further, when the position of the corner of the outer peripheral groove of the spool is not close to these two opening ends and the spool is located at a position sufficiently distant so as not to form a throttle, the spool is supplied from a high pressure source. The hydraulic fluid does not pass through the throttle,
Via the supply port, via the space formed by the outer peripheral groove of the spool and the inner peripheral surface of the sleeve, the control room port,
It is introduced into the control room via the communication passage. Therefore, as described above, the speed of increasing the control chamber pressure can be improved.

As described above, according to the present invention, depending on the position of the spool, a case where high pressure is introduced into the control chamber through the two-stage throttle section and a case where high pressure is introduced into the control chamber without passing through the throttle section are described. Can be switched, it is only necessary to form one outer circumferential groove on the outer circumference of the spool, and it is not necessary to form an inner circumferential groove on the inner circumference of the sleeve. Therefore, the axial length of the sleeve and the spool can be reduced, and the processing cost of these can be reduced. In the present invention, the supply port and the control chamber port provided on the sleeve need not be formed on the same cross section in the axial direction as long as they are provided at the same position in the axial direction.

[0016] More preferably, the supply port and the control chamber port are formed coaxially in the axial direction and the vertical direction on the same cross section in the axial direction. According to this, when the supply port and the control chamber port are formed on the sleeve, the processing can be performed simultaneously by one drilling or the like, so that the processing cost can be further reduced.

More preferably, the communication passage is formed in parallel with the axial direction. According to this, when processing the sleeve, the outer peripheral surface and the inner peripheral surface can be processed and the communication passage can be processed by one chucking operation. Therefore, the processing cost can be further reduced.

Also, a master cylinder for operating a master cylinder piston in response to brake pedal operation to generate a brake fluid pressure, a high pressure source for supplying high pressure, and utilizing a high pressure from the high pressure source for operating in response to brake pedal operation. A brake valve booster that includes a spool valve device that includes a spool that adjusts the hydraulic pressure in the control chamber and that applies the hydraulic pressure in the control chamber to the master cylinder piston as servo pressure to assist brake pedal operation. In this, the spool valve device may be constituted by the above-described spool valve device according to the present invention. As described above, in the spool valve device used in the brake hydraulic pressure booster, the spool position is different between the normal brake operation and the sudden brake operation, and the high pressure source of the hydraulic fluid is used during the normal brake operation. It is necessary to reduce the noise introduced into the control room from the vehicle, and to increase the speed of increasing the control room pressure during a sudden braking operation. Therefore, depending on the position of the spool, it is necessary to switch between a case where high pressure is introduced into the control chamber through the two-stage throttle section and a case where high pressure is introduced into the control chamber without passing through the throttle section. If the spool valve device according to the present invention is used for the hydraulic booster, the axial length can be shortened and the cost can be reduced for the entire brake hydraulic booster. It becomes possible.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. First, an outline of a mechanical configuration of a brake hydraulic pressure booster using a spool valve device according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is an axial sectional view of the brake hydraulic booster in a state where a brake pedal is not depressed.

In FIG. 1, in a substantially cylindrical master cylinder case 1 constituting an overview of a brake hydraulic booster, tandemly provided in a stepped cylindrical hole 1g provided therein. A first master cylinder piston 7 and a second master cylinder piston 11 (master cylinder piston) are provided slidably in the axial direction in a liquid-tight manner. The first master cylinder piston 7 is connected via a member 5 to the rod 3 that operates in conjunction with a brake pedal (not shown). Further, the first master cylinder piston 7 is connected to the second master cylinder 11 via a member 9 integrally fixed to the left end portion. Therefore, the member 5, the first master cylinder piston 7, the member 9, and the second master cylinder piston 11 move in the axial direction integrally with the operation of the brake pedal (not shown).
Here, the master cylinder case 1, the rod 3, the member 5,
The first master cylinder piston 7, the member 9, and the second master cylinder piston 11 constitute a master cylinder.

Stepped cylindrical hole 1g of master cylinder case 1
In FIG. 1, the second master cylinder piston 11
The regulator piston 23 is disposed slidably in the axial direction in a liquid-tight manner at a predetermined distance to the left in FIG. A pressure chamber 17 is formed by the right end of the regulator piston 23, the left end of the second master cylinder piston 11, and the inner surface of the stepped cylindrical hole 1g.
Is a communication hole 23 provided in the regulator piston 23.
a, it communicates with a front wheel side wheel cylinder (not shown) through a space 25 provided in an annular groove of the regulator piston 23 and a port 1 b provided in the master cylinder case 1. Accordingly, the hydraulic pressure in the pressure chamber 17 becomes the braking hydraulic pressure that acts on the front wheels as it is.

A rod 21 is provided between the right end of the regulator piston 23 and the left end of the second master cylinder piston 11 so as to be relatively movable. The rod 21 is described in detail. Although omitted, the distance between them is configured to be limited to a predetermined value. A spring 19 for urging the two in a direction to separate them from each other is provided. In the expected state shown in FIG. 1, the regulator piston 23 and the second master cylinder piston 11 are urged by the urging force of the spring 19.
Are separated from each other by the predetermined value.

At the left end of the second master cylinder piston 11, there is provided an on-off valve 15 which can communicate and shut off the pressure chamber 17 and a reservoir (not shown). Although not described in detail, the on-off valve 15 has a structure that opens and closes according to the relative position between the rod 21 and the second master cylinder piston 11. When the regulator piston 23 and the second master cylinder piston 11 are separated by the predetermined value by the urging force of the spring 19 as shown in the initial state of FIG.
Is most protruded leftward relative to the second master cylinder piston 11, and the on-off valve 15
It is open. Therefore, in the initial state shown in FIG. 1, the pressure chamber 17 includes the on-off valve 15, the communication holes 11 b and 11 a provided in the second master cylinder piston 11, the outer peripheral surface of the second master cylinder piston 11, and the master cylinder case 1.
And a reservoir (not shown) through a space defined by the stepped cylindrical hole 1g and a communication hole 1a provided in the master cylinder case 1.

As will be described later, after operating the brake pedal,
The regulator piston 23 relatively approaches the second master cylinder piston 11 from the above-mentioned predetermined value against the urging force of the spring 19, and the relative position of the rod 19 with respect to the second master cylinder piston 11 is different from the initial position. When moving to the right by the fixed amount, the on-off valve 15 is closed. After the on-off valve 15 is closed, the pressure chamber 17
It is separated from a reservoir (not shown), and the hydraulic pressure in the pressure chamber 17 changes according to the pressing force of the second master cylinder piston 11 to the left in FIG.

Stepped cylindrical hole 1g of master cylinder case 1
Further, a sleeve 47 is inserted into the inside of the master cylinder case 1 in a liquid-tight manner at a predetermined distance to the left in FIG. 1 with respect to the regulator piston 23. It is fixed in the axial direction by a plug 41 inserted and fixed from the left end. Plug 4
A blind plug 41 is liquid-tightly inserted into and fixed to the inside 1 to prevent the hydraulic fluid in the master cylinder case 1 from flowing out. A spool 29 is inserted into the sleeve 47 so as to be slidable in the axial direction. The right end of the spool 29 is inserted into a concave portion provided at the left end of the regulator piston 23. Slidably in the axial direction. The integral spool 29 and the regulator 23
Is always urged rightward by the urging force of the spring 33 whose one end is in contact with the right end face of the sleeve 47 in order to ensure the initial position when not in operation. Spool 29
Is exposed to the return chamber 35, and the return chamber 35 communicates with a reservoir (not shown) via the return port 1h. This spool 29 and sleeve 47
These constitute the spool valve device 27.

The spool 29 is slidably inserted into the cylindrical hole of the plug 41, and is provided with a member 37 exposed to the return chamber 35 from an elastic body disposed in the recess of the plug 41. 1 receives a reaction force from the reaction disk 39 to the right in FIG. That is, the spool 29 moves relative to the sleeve 47 in the axial direction due to the balance between the leftward force received from the regulator piston 23 and the rightward force received from the reaction disk 39. As will be described later, depending on the axial position of the spool 29, the left end surface of the reaction disk 23, the right end surface of the sleeve 47, and the spool 2
9 and the inner surface of the stepped cylindrical hole 1g of the master cylinder case 1 control the fluid pressure in the control chamber 31.

The hydraulic pressure in the control chamber 31 controlled by the axial position of the spool 29 is supplied to a reaction chamber 45 through a communication hole 1 d provided in the master cylinder case 1. Reaction disk 3
9 is bent rightward in FIG. 1, and the bending causes the spool 29 to receive a rightward reaction force.

The hydraulic pressure in the reaction force chamber 45 is introduced to the right end face of the first master cylinder piston 7 through a communication hole 1f provided in the master cylinder case 1, and the hydraulic pressure is The master cylinder piston 7 receives a force in the left direction, and the operating force of the brake pedal is assisted. Therefore, the hydraulic pressure in the control room 31 functions as a servo pressure for assisting the brake pedal operation. The hydraulic pressure in the control chamber 31 introduced to the right end surface of the first master cylinder piston 7 communicates with a not-shown rear wheel cylinder via a communication hole 1c.
Therefore, the hydraulic pressure in the control chamber 31 becomes the braking hydraulic pressure acting on the rear wheel side as it is.

Next, referring to FIG.
Will be described. In addition, FIG.
FIG. 2 shows a non-operation state in which the control room pressure is low.
(B) shows a state where the control chamber pressure is being increased.

The spool 29 has an outer peripheral groove 29 on its outer periphery.
a is provided in series. The sleeve 47 is provided with a supply port 47b for introducing the high pressure supplied from the accumulator ACC into the control chamber 31 via the port 1e, and the sleeve 47 has a supply port 47b.
Control room port 47 at the same position in the axial direction
f is provided. The supply port 47b and the control chamber port 47f are formed coaxially in the axial direction and the vertical direction on the same plane in the axial direction. Can be. The control chamber port 47f communicates with the control chamber 31 via a communication hole 47g (communication passage) formed parallel to the axial direction. The sleeve 47 is provided with communication holes 47c and 47d for communicating the control chamber 31 with the return chamber 35.

Here, when the spool 102 is located at the axial position shown in FIG. 2A, that is, in the expected state shown in FIG. 1, the open end 47ba of the supply port 47b is opened.
Is closed by the corner 29aa of the outer peripheral groove 29a of the spool 29, so that the high pressure from the accumulator ACC is
It is not introduced into the control room 31. In addition, the communication hole 4
Since the open end of 7d communicates with the return chamber 35 at the position of the corner 29c of the spool 29, the control chamber 31 communicates with the return chamber 35. Therefore, at the spool position shown in FIG. 2A, the control chamber pressure is maintained at a low pressure.

When the spool 29 slides leftward from the state shown in FIG. 2A to the position shown in FIG. 2B, the open end of the communication hole 29d is closed by the corner 29c of the spool 29, and the control is performed. The communication between the chamber 31 and the return chamber 35 is released. Further, the first end is formed by the open end 47ba of the supply port 47b and the corner 29aa of the outer circumferential groove 29a of the spool 29.
An aperture portion (variable aperture) is formed, and a second aperture portion (variable aperture) is formed simultaneously with the first aperture portion by the opening end of the control chamber port 47f and the corner portion 29aa of the outer peripheral groove 29a of the spool 29. The high pressure from the accumulator ACC is supplied to the supply port 47b, the first throttle, the annular space formed by the outer peripheral groove 29a of the spool 29 and the inner circumference of the sleeve 47, the second throttle, the control chamber port 47f, and the communication hole. It is introduced into the control room 31 via 47g, and the control room pressure is controlled. Here, the introduced hydraulic fluid is decompressed every time it passes through the throttle unit, but since it passes through the two-stage throttle unit, compared to the case where it passes through the one-stage throttle, The differential pressure generated before and after one throttle can be reduced. Therefore, it is possible to suppress the occurrence of cavitation when the hydraulic fluid passes through the throttle portion, and it is possible to reduce the introduction noise of the hydraulic fluid due to the occurrence of cavitation as much as possible.

When the spool 29 moves further to the left from the position shown in FIG.
The position of the corner 29aa of 9a moves relative to the position of the supply port 47b of the sleeve 47, and
Since the throttle portion of the stage disappears at the same time, the high pressure from the accumulator ACC is applied to the control room 31 without passing through the throttle portion.
Will be introduced within. So, in this case,
The speed at which the control room pressure is increased can be improved, and high responsiveness of the assisting force for operating the brake pedal can be ensured.

The mechanical configuration of the brake hydraulic pressure booster using the spool valve device according to the embodiment of the present invention has been outlined above. Next, the operation will be described. When the brake pedal (not shown) is depressed from the state shown in FIG. 1 showing the initial state, which is a non-operation state, the second pedal is moved via the rod 3, the member 5, the first master cylinder piston 7, and the member 9 with the movement of the brake pedal. The cylinder piston 11 also moves to the left in FIG. 1 integrally with the brake pedal. Second
When the master cylinder piston 11 moves to the left, the biasing force of the spring 19 causes the regulator piston 23
Also moves to the left integrally with the second master cylinder piston 11, and the spool 29 integrated with the regulator piston 23 also moves to the left.

When the spool 29 moves relative to the sleeve 47 to the position shown in FIG.
The hydraulic pressure from the accumulator ACC is introduced into 1, and the hydraulic pressure in the control chamber 31 increases. The raised hydraulic pressure in the control chamber 31 is supplied to the reaction force chamber 45 and also to the right end face of the first master cylinder piston 7 as servo pressure.

The first master cylinder piston 7 to which the servo pressure is supplied applies a leftward assisting force to the second master cylinder piston 11 by the servo pressure, and the second master cylinder piston 11 is moved by the assisting force. It moves to the right relative to the regulator piston 23. As a result, the on-off valve 15 is closed, and the hydraulic pressure in the pressure chamber 17 can be generated. The hydraulic pressure in the pressure chamber 17 is a pressure corresponding to the resultant force of the operation force of the brake pedal (not shown) acting on the second master cylinder piston 11 to the left and the force of the servo pressure, and the front wheel cylinder (not shown) Supplied to

After the on-off valve 15 is closed, the regulator piston 23 balances the leftward force received from the hydraulic pressure in the pressure chamber 17 and the rightward force received from the hydraulic pressure in the control chamber 31. To slide in the axial direction, and as a result, the spool 29
Also slides integrally with the regulator piston 23. On the other hand, the spool 29 receives a rightward reaction force from the reaction disk 39 bent by the liquid pressure in the reaction force chamber 45, and the spool 29 moves rightward by the reaction force, as shown in FIG. When the state moves from the state b) to the state shown in the state (a), the hydraulic pressure in the control chamber 31 decreases. Therefore, the spool 29 slides with respect to the sleeve 47 by the balance between the hydraulic pressure in the control chamber 31 and the hydraulic pressure in the pressure chamber 17,
The hydraulic pressure in the control room 31 is controlled by increasing / decreasing the hydraulic pressure in the control room 31. Hydraulic pressure in the controlled control room 31;
That is, the pressure receiving area of each piston, the characteristics of the reaction disk, and the like are tuned so that the brake fluid pressure on the rear wheel side is substantially equal to the fluid pressure in the pressure chamber 17, that is, the brake fluid pressure on the front wheel side.

At the time of normal brake operation, FIG.
Since the spool 29 is located near the position shown in FIG.
In this state, the introduction sound of the working fluid from the accumulator ACC into the control room 31 is reduced by the effect of the two-stage throttle described above. On the other hand, at the time of sudden braking operation, the rightward reaction force received from the reaction disc 39 received by the spool 29 cannot catch up with the leftward force from the regulator piston 23 received by the spool 29,
The spool 29 may momentarily move to the left with respect to the sleeve 47 from the position shown in FIG. In this case, the two-stage throttle described above disappears, the speed of increasing the control chamber pressure can be improved, and high responsiveness of the assisting force of the brake pedal operation can be secured.

According to the brake hydraulic booster using the spool valve device 27 according to the embodiment of the present invention described above,
Depending on the position of the spool 29, it is possible to switch between a case where high pressure is introduced into the control chamber 31 through the two-stage throttle section and a case where high pressure is introduced into the control chamber 31 without passing through the throttle section. I have. Further, in the spool valve device 27 according to the present invention used here, the outer periphery of the spool 29 is
It is only necessary to form two outer grooves 29a, and there is no need to form an inner groove as shown in the related art on the inner periphery of the sleeve 47. Therefore, the sleeve 47 and the spool 2
9 can be reduced in length in the axial direction, and the processing cost can be reduced.

In the sleeve 47, the supply port 47b and the control chamber port 47f are formed coaxially in the axial direction and the vertical direction on the same cross section in the axial direction. When machining the control room port 47f and the control room port 47f, the machining can be performed simultaneously by one drilling or the like, so that the machining cost can be further reduced.

Further, the communication path 4 in the sleeve 47
Since 7 g is formed in parallel with the axial direction, when the sleeve 47 is processed, the outer peripheral surface and the inner peripheral surface can be processed and the communication passage 47 g can be processed by one chucking operation. Therefore, the processing cost can be further reduced.

Therefore, according to the brake hydraulic booster using the spool valve device 27 according to the above-described embodiment of the present invention, the axial length can be reduced even for the entire brake hydraulic booster. And cost can be reduced.

[0043]

As described above, according to the present invention,
When the high-pressure hydraulic fluid is introduced into the control chamber, the spool valve device can switch between a case where the high-pressure hydraulic fluid is introduced through a two-stage throttle portion and a case where the high-pressure hydraulic fluid is introduced without a throttle portion depending on the position of the spool. The length can be shortened and an inexpensive one can be provided.

[Brief description of the drawings]

FIG. 1 is an axial sectional view of a brake hydraulic booster in a state where a brake pedal is not depressed according to the present invention.

FIGS. 2A and 2B are enlarged views around the spool valve device in FIG. 1, wherein FIG. 2A shows a non-operating state in which the control chamber pressure is low, and FIG. The state under pressure is shown.

FIGS. 3A and 3B are enlarged views around a spool valve device in the related art, in which FIG. 3A shows a non-operating state in which the control chamber pressure is low, and FIG. 3B shows a state in which the control chamber pressure is being increased; Is shown.

[Explanation of symbols]

7 1st master cylinder piston (master cylinder piston) 11 1st master cylinder piston (master cylinder piston) 27 Spool valve device 29 Spool 29a Outer peripheral groove, 29aa Corner of outer peripheral groove 31 Control chamber 47 Sleeve 47b Supply port, 47ba supply port Open end of 47f Control room port, 47g Communication hole (communication passage)

Claims (4)

[Claims] 1. A sleeve having a supply port communicating with a high-pressure source, and a spool which is slidably inserted in the sleeve in the axial direction and has an outer peripheral groove formed in an outer periphery. In a spool valve device in which a variable throttle is formed by a corner portion of the outer peripheral groove and an opening end of the supply port by an axial displacement with respect to a sleeve and a hydraulic pressure in a control chamber is adjusted, the sleeve includes:
A spool valve device comprising: a control chamber port that opens at the same position in the axial direction as an open end of the supply port; and a communication path that communicates the control chamber port with the control chamber. 2. The spool valve device according to claim 1, wherein the supply port and the control chamber port are formed coaxially in the axial direction and the vertical direction on the same cross section in the axial direction. 3. The spool valve device according to claim 1, wherein the communication passage is formed in parallel with the axial direction. 4. A master cylinder for operating a master cylinder piston in response to a brake pedal operation to generate a brake fluid pressure, a high pressure source for supplying a high pressure, and operating in response to a brake pedal operation to reduce a high pressure from the high pressure source. A brake valve that includes a spool valve that includes a spool that adjusts the hydraulic pressure in the control chamber by utilizing the hydraulic pressure in the control chamber as a servo pressure to the master cylinder piston to assist the brake pedal operation. A brake hydraulic pressure booster, wherein the spool valve device is configured by the spool valve device according to any one of claims 1 to 3.