JP2001048002A - Hydraulic booster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic booster of lever type which can perform output control in no relation to an input of an input member during operation. SOLUTION: At operation time, an input shaft 4 is advanced, and a lever 27 is turned to operate a control valve 8, which generates an operating hydraulic pressure in accordance with an input. This operating hydraulic pressure is introduced to a power chamber 6 and reaction force chamber 58, a primary piston 37 is operated by this hydraulic pressure to generate a master cylinder pressure. Here, by discharging a fluid of the reaction force chamber 58 to a stroke simulator 68, a stroke of the input shaft 4 is ensured, and reaction force is applied to the input shaft 4 by a hydraulic pressure of the reaction force chamber 58. During this operation, a valve spool 10 is moved in an inoperative direction by a solenoid 80, so as to connect the power chamber 6 to a reservoir, consequently a hydraulic pressure of the power chamber 6 is decreased, to reduce the master cylinder pressure. In this case, reducing control of the master cylinder pressure is performed in no relation to the input.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a hydraulic booster which boosts an operating force of an operating means to a predetermined magnitude by a hydraulic pressure controlled by a control valve and outputs the boosted power. The input stroke can be set variously without being affected by the operation of the actuator such as the master cylinder which is operated by the output of the hydraulic booster. The invention belongs to the technical field of a hydraulic booster capable of controlling the output of a power device.

[0002]

2. Description of the Related Art For example, in a brake system of an automobile, a brake hydraulic booster for generating a large brake hydraulic pressure by boosting a pedal pressure of a brake pedal to a predetermined magnitude by a hydraulic pressure is conventionally used. ing. This brake hydraulic booster can obtain a large braking force with a small brake pedal depression force, thereby ensuring braking and reducing the driver's labor.

In such a conventional brake hydraulic booster, a control valve is operated by an input based on a pedaling force of a brake pedal to generate a hydraulic pressure according to the input, and the hydraulic pressure is supplied to a power chamber. With the introduction, the input is boosted at a predetermined boost ratio and output. Then, by operating the piston of the brake master cylinder with the output of the brake hydraulic pressure booster, the master cylinder generates a master cylinder pressure, and the master cylinder pressure is introduced to the wheel cylinder as the brake hydraulic pressure. The brake is activated.

[0004]

By the way, in the conventional brake system, for example, anti-lock control (ABS), brake assist control used for starting a slope, regenerative cooperative brake control when regenerative braking is used in combination, and the like. Various brake controls such as brake force control during the operation of a brake, automatic control such as brake control for headway control, collision avoidance brake control for avoiding obstacles, and brake control for traction control (TRC) Has been done. Such brake control is often performed in the brake circuit up to the wheel cylinder ahead of the master cylinder, but when the brake control is performed in the brake circuit ahead of the master cylinder, the input stroke of the hydraulic booster is However, it is required not to be affected by the brake control because of, for example, a brake feeling.

However, in a conventional brake system combining a brake hydraulic booster and a brake master cylinder, the stroke of the master cylinder piston is determined from the relationship between the master cylinder and the wheel cylinder. The stroke of the input shaft of the brake hydraulic booster, that is, the pedal stroke of the brake pedal is determined.
For this reason, the stroke on the input side is affected by the brake control in the brake circuit ahead of the master cylinder,
With a conventional combination of a brake hydraulic booster and a brake master cylinder, it has been difficult to reliably and sufficiently meet the above-mentioned requirements.

Further, when the stroke characteristics of the brake pedal on the input side are changed due to a brake feeling or the like, the brake master cylinder and the brake circuit preceding the brake master cylinder are also affected. These outputs need to be changed. In addition, when the output side is changed, the output characteristics of the brake are affected, so that the entire brake system needs to be reviewed and changed, and the scale of the change becomes large.

Further, even if the brake circuit before the master cylinder changes in various ways depending on the type and size of the vehicle, it is desired that the input side be as little affected by such different brake circuits as possible. Therefore, if the input side and the output side are simply separated to generate an output irrespective of the input stroke, the stroke on the input side stops, and the stroke on the input side cannot be secured.

Therefore, conventionally, a stroke simulator is provided in the brake circuit before the master cylinder so that the input stroke of the brake hydraulic booster is not affected by the brake control before the master cylinder. In addition, it has been proposed to secure an input stroke. However, the special provision of the stroke simulator requires many components such as a stroke cylinder and an electromagnetic on-off valve used in the stroke simulator, which not only complicates the configuration but also increases the cost. Will be. Further, even when a stroke simulator or the like is provided, there is a problem that it is necessary to ensure that the brake operation can be performed when the hydraulic pressure source fails.

Further, in the anti-lock control system, when a wheel tends to lock at the time of braking, it is desired to control the braking force so that the tendency to lock the wheel can be eliminated. Furthermore, in the regenerative brake cooperative system combined with the regenerative brake, when the regenerative brake operation is activated during the operation of the brake hydraulic booster, only the braking force by the regenerative brake operation is applied.
It is necessary to reduce the braking force due to the operation of the brake hydraulic booster. In such a case, it is desired that the output of the brake hydraulic booster be reduced accordingly. Also, in a brake system combined with a brake assist system, it is possible to easily start on a slope by controlling the release of the brake operation,
When the driver cannot depress the pedal with a predetermined pedaling force when the brake hydraulic booster is operated, the predetermined braking force cannot be obtained, and when the brake assist is required, the brake by the operation of the brake hydraulic booster is required. In such a case, it is desired to increase the output of the brake hydraulic booster. When the brake control is performed during the braking operation,
Even if a stroke simulator or the like is provided, it is required that the brake pedal is not affected.

Further, in the headway control brake system, it is desirable to automatically activate the brake when the headway distance between the vehicle and the preceding vehicle is reduced during traveling to maintain the headway distance at a constant value. In a brake system, when there is an obstacle or the like in front of the vehicle and it is likely to collide with the obstacle or the like, it is desired to automatically operate the brake to avoid collision with the obstacle or the like. Further, in a traction control system, if a driving wheel tends to slip when the vehicle starts, the brake is automatically applied to the driving wheel to eliminate the slipping tendency and to ensure that the vehicle can start. Is desired.

[0011] When the automatic braking is performed as described above, it is required that the brake pedal is not affected by the provision of a stroke simulator or the like. In addition, it is required to form a system for performing such a braking force control or an automatic brake control during the operation of the brake with a simple configuration. Further, it is also required that the input-stroke characteristic, the input-brake pressure characteristic, the stroke-brake pressure characteristic, and the like can be changed with a simple configuration according to the situation of a vehicle or the like.

The present invention has been made in view of such circumstances, and has as its object to variously change the stroke characteristics of the input side without requiring a large-scale change without being influenced by the output side. It is an object of the present invention to provide a compact and inexpensive lever-type hydraulic booster that can operate reliably when a hydraulic pressure source fails. It is another object of the present invention to provide a lever-type hydraulic booster capable of performing output control during operation regardless of an input of an input member.

[0013]

In order to solve the above-mentioned problems, a hydraulic booster according to the present invention has an input member that strokes with an input applied during operation, and an operation controlled by the input member. A control valve for controlling the hydraulic pressure of the hydraulic pressure source in accordance with the operation amount of the input member to generate a hydraulic pressure for operating the actuator, and for operating the actuator when the hydraulic pressure is introduced. A hydraulic chamber that generates a hydraulic pressure corresponding to the input of the input member and applies a reactive force to the input member by the hydraulic pressure. The pressure acts on the control valve in a non-operating direction, and an elastic member is disposed between the control valve and the input member, and the elastic member is operated in accordance with an operation amount of the input member. Acting on the control valve in the operating direction. The control valve is configured to operate in response to the input so that the acting force by the hydraulic fluid and the acting force by the elastic member are balanced, and the reaction chamber is an input member. When the hydraulic pressure source is normal, the reaction force chamber is connected to the stroke simulator to secure the stroke of the input member, and the hydraulic pressure source is secured. When the source fails, the reaction chamber is shut off from the stroke simulator and is sealed, so that the actuator is operated by the stroke of the input member.

According to a second aspect of the present invention, the control valve comprises:
A valve spool whose operation is controlled by an operating force of the elastic member being applied in an operating direction and an operating hydraulic pressure being applied in a non-operating direction, and a valve fixed to a housing of the hydraulic booster A sleeve, and the valve spool is attached to the valve sleeve in response to an input from the input member so that the acting force of the hydraulic fluid acting on the valve spool and the acting force of the elastic member are balanced. It is characterized by being relatively moved with respect to.

Further, according to a third aspect of the present invention, the elastic member is rotated between the elastic member and the control valve by the action force of the elastic member in accordance with the operation amount of the input member, and actuated by the control valve. A lever that acts in the direction, the position of the pivot point of the lever is constant irrespective of the stroke of the input member, and the control valve is operated by the hydraulic fluid pressure and by the rotation of the lever. The operation is controlled in accordance with the input member so that the balance is achieved. Further, the invention of claim 4 generates an urging force for urging the control valve in at least one of an operating direction and a non-operating direction, thereby controlling the hydraulic fluid pressure regardless of an input of the input member. It is characterized by providing an electromagnetic solenoid.

[0016]

In the hydraulic booster of the present invention having the above-described structure, the elastic member generates an operating force by the input applied to the input member, and the control valve is operated and controlled by the operating force. The hydraulic fluid pressure is controlled in accordance with the input of the input member. Then, a hydraulic pressure controlled by the control valve is generated as an output, and the actuator is directly operated by the output hydraulic pressure. Therefore, in the hydraulic booster of the present invention, the input side and the output side operate separately.
In this case, since the hydraulic booster includes the stroke simulator, the input stroke of the input member is ensured, and the input stroke of the input member can be varied without being affected by the control state of the output side beyond the actuator. It can be set.

Further, during operation of the hydraulic booster, the hydraulic pressure control means controls the hydraulic pressure for operating the actuator, that is, the output of the hydraulic booster, regardless of the input of the input member. Become like As a result, the operation of the hydraulic booster such as the above-described control of the hydraulic fluid pressure reduction during the regenerative braking operation of the regenerative brake cooperative system and the increase of the hydraulic fluid pressure during the brake assist of the brake assist system are performed. It is possible to easily and flexibly cope with a system that requires control of the working fluid pressure regardless of the input of the input member.

Furthermore, in the hydraulic booster in a state where the operation by the input member is not performed, the hydraulic pressure control means controls the hydraulic pressure for operating the actuator regardless of the operation of the input member. become. This makes it possible to easily and flexibly cope with a system that requires automatic operation control, such as the above-described automatic brake control such as the inter-vehicle control brake, the collision avoidance brake control, or the traction control brake control. Become.

Further, since the control valve of the conventional hydraulic booster can be used as the control valve with almost no change,
The hydraulic booster of the present invention has a simple structure and is inexpensive without using any special parts. Further, when the hydraulic pressure source fails, the actuator is operated by the advance of the input member, and the actuator is reliably operated even when the hydraulic pressure source fails.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a brake hydraulic booster to which a first embodiment of a hydraulic booster according to the present invention is applied, and FIG. 2 is control of the brake hydraulic booster shown in FIG. FIG. 3 is a partially enlarged cross-sectional view of the master cylinder portion shown in FIG. 1. In the following description, the up, down, left, and right directions represent the up, down, left, and right directions in the drawings, respectively, and the front and rear directions respectively correspond to the left and right in the drawings.

As shown in FIG. 1, in the brake hydraulic booster 1 of the first embodiment, a master cylinder described later is integrally connected, and the master cylinder is operated by the output of the brake hydraulic booster 1. It has become so. As shown in FIGS. 1 and 2, the brake hydraulic booster 1 includes a housing 2 for a brake hydraulic booster. The housing 2 for the brake hydraulic booster includes an input piston 3.
The input piston 3 is connected to a brake pedal (not shown), and an input shaft 4 is connected to the input piston 3. A power piston 5 is provided in the brake hydraulic booster housing 2 coaxially with the input shaft 4 in a fluid-tight manner. The power piston 5 defines a power chamber 6 in front of the power piston 5. I have. As described above, the power piston 5 functions as a plug that defines the power chamber 6 in the brake hydraulic booster 1 of this example, and does not perform the function of generating the output of the brake hydraulic booster 1. A lever support portion 5a (described later) at the rear end of the power piston 5 is disposed so as to be movable by a predetermined distance between the first and second step portions 2a and 2b of the housing 2, and is contracted in the power chamber 6. The spring 7 contacts and is fixed to the second step portion 2b.

The front end 4a of the input shaft 4 has a power piston 5
Is slidably fitted in the axial bottomed hole 5b in a liquid-tight manner. A reaction force chamber 58 is formed by the front end 4a of the input shaft 4 in the bottomed hole 5b in front of the front end 4a of the input shaft 4. When the input shaft 4 is not operated, the reaction force chamber 58 has an axial hole 4 formed in the front end 4 a of the input shaft 4.
d and a radial hole 4e, an annular groove 5e and an inclined hole 5f provided in the power piston 5, and are connected to a chamber 56 which will be described later.
e and the annular groove 5e are shut off from the chamber 56. Further, the reaction force chamber 58 is connected to a shutoff valve 67 and a stroke simulator 68 provided in the housing 2 through an inclined hole 5g formed in the power piston 5 and a passage hole 2d of the housing 2.

The shutoff valve 67 is provided in a hole of the housing 2 and has a cylindrical valve seat member 70 having a valve seat 69, a ball valve 71 which can be seated on the valve seat 69, and a ball valve 71.
A valve spring 72 which constantly urges the ball valve 71 to be seated on the valve seat 69, and a valve which separates the ball valve 71 from the valve seat 69 by the action of the hydraulic pressure of the accumulator of the hydraulic pressure source when the hydraulic pressure source is normal. An operating piston 73 and a piston spring 74 that constantly urges the valve operating piston 73 in a direction opposite to the direction of action of the hydraulic pressure of the accumulator are provided.

The stroke simulator 68 is provided in a hole of the housing 2 in a liquid-tight and slidable manner.
And the first and second simulator springs 77 and 78 (the spring force of the first simulator spring 77> the spring force of the second simulator spring 78) which constantly urges the simulator piston 76 in the direction in which the liquid storage chamber 75 contracts. And In this case, the ball valve 71 side of the shutoff valve 67 passes through the reaction hole 5d through the passage hole 2d and the inclined hole 5g.
8 and the valve operating piston 73 side of the shutoff valve 67 is always connected to the liquid storage chamber 75 through the passage hole 79. When receiving the normal hydraulic pressure of the accumulator, the valve operating piston 73 pushes the ball valve 71 as shown to separate from the valve seat 69, opens the shut-off valve 67, and opens the reaction force chamber 58. When the hydraulic pressure source fails and the accumulator does not receive the normal hydraulic pressure, the piston valve 74 retracts (moves to the right) to move the ball valve 71. The valve seat 69 is seated, the shut-off valve 67 is closed, and the reaction force chamber 58 is
It is designed to be shut off from a closed state.

Further, a control valve 8 is provided in the housing 2. The control valve 8 includes a valve sleeve 9 fitted and fixed in a liquid-tight manner in the housing 2 and a valve spool 10 slidably fitted in the valve sleeve 9. The cylinder hole in the axial direction of the valve sleeve 9 is provided with a step 9a, and is formed as a stepped hole including a small-diameter cylinder hole 9b at the front end and a large-diameter cylinder hole 9c at the rear end from the center. The valve sleeve 9 has first to fifth radial holes 11, 12, 1 from its front end side.
3, 14, 15 are respectively drilled. In this case, the first radial hole 11 is formed in the small-diameter cylinder hole 9b, and the second to fifth radial holes 12, 13, 14, 1 are formed.
5 are both formed in the large-diameter cylinder hole 9c.

The first radial hole 11 is always connected to a reservoir (not shown) for a brake hydraulic booster through the passage holes 16, 17, 18 of the housing 2 and, therefore, is located in front of the valve spool 10. A space 19 in the valve sleeve 9 is always in communication with the reservoir. Second
The radial holes 12 are formed in the passage holes 20, 21, 22 of the housing 2.
And is always connected to the power room 6
The radial hole 13 is always connected to the reservoir for the brake hydraulic booster through the passage hole 18. Further, the fourth radial hole 14 is always connected to an accumulator of a hydraulic pressure source (not shown) through the passage hole 23 and the hydraulic pressure introduction port 24 of the housing 2, and is connected to the accumulator by a pump (not shown) of the hydraulic pressure source. The stored hydraulic pressure is constantly being introduced. Further, the fifth radial hole 15 is always connected to the power chamber 6 through the passage hole 22 of the housing 2.

The valve pool 10 is formed as a step having a small-diameter spool portion 10a at the front end and a large-diameter spool portion 10b from the center to the rear end. In this case, the small-diameter spool portion 10a is fitted in the small-diameter cylinder hole 9b of the valve sleeve 9 in a liquid-tight and slidable manner, and the large-diameter spool portion 10b is
c so as to be slidable. This valve spool 1
0, the small-diameter spool portion 10a and the large-diameter spool portion 10b
And a second annular groove 26 is formed in the large diameter spool portion 10b.

The first annular groove 25 is always connected to the second radial hole 12 and is connected to the third radial hole 13 when the valve spool 10 shown in FIG. The hydraulic pressure in the power chamber 6 is set to the atmospheric pressure, and the power chamber 6 is disconnected from the third radial hole 13 when the valve spool 10 is operated forward, so that the power chamber 6 is connected to the brake hydraulic pressure booster. From the reservoir. The third radial hole 13 and the first annular groove 25 constitute a hydraulic pressure discharge valve. On the other hand, the second annular groove 26 is always connected to the fifth radial hole 15, and is shut off from the fourth radial hole 14 when the valve spool 10 is not operated to shut off the power chamber 6 from the accumulator of the hydraulic pressure source. In addition, when the valve spool 10 is moved forward, the power chamber 6 is connected to the fourth radial hole 14 to connect the power chamber 6 to the accumulator, and the hydraulic pressure of the accumulator is introduced into the power chamber 6. The fourth radial hole 14 and the second annular groove 26 constitute a hydraulic pressure supply valve.

When the hydraulic pressure discharge valve is closed and the hydraulic pressure supply valve is opened to introduce hydraulic pressure into the power chamber 6 as described later, the hydraulic pressure in the power chamber 6 is applied to the first annular groove 25. When the hydraulic pressure of the first annular groove 25 acts on the small-diameter and large-diameter spool portions 10a and 10b having different pressure receiving areas, the valve spool 10 is urged rightward, that is, toward the inoperative position. It has become.

Further, in the brake hydraulic booster 1 of the first embodiment, an electromagnetic solenoid 80 is provided on the housing 2 coaxially with the valve spool 10. When the electromagnetic solenoid 80 is excited, its movable plunger 80a presses the valve spool 10 in the non-operation direction. Further, one end of a lever 27 is swingably supported by a first support pin 28 on the lever support portion 5 a of the power piston 5. The other end of the lever 27 is swingably supported by a valve operating member 29 by a second support pin 30.

A retainer 62 is slidably fitted to the input shaft 4, and a single two-return spring 31 is contracted between the retainer 62 and the input piston 3. This return spring 31
Always urges the input piston 3 and the input shaft 4 rearward with respect to the retainer portion 62. And the input shaft 3 shown
Is not actuated, the input piston 3 and the input shaft 4 are urged rearward by the spring force of the return spring 31, whereby the flange portion 4b of the input shaft 4 abuts on the retainer portion 62,
A retraction limit of the input shaft 4 is defined.

The retainer portion 62 has a vertically long hole 62a.
An engagement pin 27a protruding inward from the lever 27 is engageable in the long hole 62a in the front-rear direction (left-right direction in the figure) and slidable in the up-down direction. Is fitted. First support pin 28 and engagement pin 27
is set to be always smaller than the distance between the engaging pin 27a and the second support pin 30 irrespective of whether the brake hydraulic booster 1 is operated or not. . The valve actuating member 29 is fitted and fixed to the valve spool 10. The valve actuating member 29 is always urged rearward by a spool return spring 32. The rear end of the illustrated valve spool 10 is set to a non-operating position where the rear end of the valve spool 10 contacts the housing 2.

Next, the master cylinder will be described. As shown in FIGS.
Is provided with a cylindrical master cylinder housing 34 having a rear end opening, and a sleeve 35 is disposed inside the master cylinder housing 34,
A cylindrical cap 36 that axially supports the sleeve 35 between the sleeve 35 and the master cylinder housing 34 is screwed to the master cylinder housing 34 in a liquid-tight manner. The cap 36 is liquid-tightly fitted and fixed to the brake hydraulic booster housing 2. The master cylinder 33 is configured as a tandem master cylinder having a primary piston 37 and a secondary piston 38 whose effective pressure receiving areas are set equal to each other.

The primary piston 37 is disposed in the power chamber 6 in the brake hydraulic booster housing 2 and in each hole of the cap 36 and the sleeve 35. The primary piston 37 includes a first cup seal 39 provided on the inner peripheral surface of the hole of the cap 36, and a sleeve 35.
And a second cup seal 40 provided on the inner peripheral surface of the hole of the cap 36 in a liquid-tight and slidable manner. Second cup seal 40
Is designed to block the flow of liquid from the front side to the rear side and allow the reverse flow. Further, the primary piston 37 is supported by the hydraulic booster housing 2 so as to be slidable in a liquid-tight manner by a third cup seal 41, and the rear end 37 a of the primary piston 37 is connected to the power chamber 6.
Faces.

The secondary piston 38 is disposed in the hole of the sleeve 35 and in the master cylinder housing 34. The secondary piston 38 has a sleeve 35
A fourth cup seal 42 provided on the inner peripheral surface of the hole of the first cylinder and a fifth cup provided on the inner peripheral surface of the hole of the master cylinder housing 34 and disposed between the master cylinder housing 34 and the sleeve 35. The seal 43 is provided so as to be liquid-tight and slidable. Fifth cup seal 43
Is designed to block the flow of liquid from the front side to the rear side and to allow the flow of liquid in the opposite direction.

A primary chamber 44 is formed between the primary piston 37 and the secondary piston 38, and a primary return spring 46 whose maximum length is regulated by a primary spring retainer 45.
Has been curtailed. A secondary chamber 47 is formed in a hole between the master cylinder housing 34 and the secondary piston 38, and a secondary return spring 49 whose maximum length is regulated by a secondary spring retainer 48 is contracted. . In that case, the spring force of the secondary return spring 49 is set to be larger than the spring force of the primary return spring 46.

The primary piston 37 has a radial hole 50.
Are drilled. The radial hole 50 is located slightly behind the cup seal 40 in the illustrated inoperative position of the primary piston 37, and at this time, the primary chamber 44 defines the radial hole 50, the rear surface of the cup seal 40, and the cap. 36, an axial hole 36a formed in the cap 36, and a cap 3 between the cup seals 39 and 40.
6 is connected to the master cylinder reservoir 51 via a circumferential groove 36b drilled in the groove 6, an inclined hole 36c extending continuously from the circumferential groove 36b in the axial direction, and a radial hole 34a of the master cylinder housing 34. It has become.

Therefore, in this state, no master cylinder pressure is generated in the primary chamber 44. In addition, the radial hole 50 is formed in the cup seal 4 by the advance of the primary piston 37.
When it is located forward of 0, the flow of liquid from the primary chamber 44 to the reservoir 51 is shut off, so that a master cylinder pressure is generated in the primary chamber 44.

The secondary piston 38 has a radial hole 52
Are drilled. The radial hole 52 is located slightly behind the cup seal 43 when the secondary piston 38 is in the non-operating position shown in the figure, and at this time, the secondary chamber 47 is in contact with the radial hole 52 and the inner peripheral surface of the sleeve 35. It is connected to the master cylinder reservoir 51 via a gap between the secondary piston 38, a radial hole 35a formed in the sleeve 35, and a radial hole 34b of the master cylinder housing 34.

Therefore, in this state, no master cylinder pressure is generated in the secondary chamber 47. Further, when the secondary piston 38 advances, the radial hole 52 is formed in the cup seal 4.
When it is located forward of 3, the flow of liquid from the secondary chamber 47 to the reservoir 51 is interrupted, so that a master cylinder pressure is generated in the secondary chamber 47.

The primary chamber 44 is connected to a wheel cylinder of one of the two brake systems via a hole 53 formed in the sleeve 35 and a primary output port 54 formed in the master cylinder housing 34. The secondary chamber 47 is connected to a wheel cylinder (not shown) of the other of the two brake systems via a secondary output port 55 formed in the master cylinder housing 34. The chamber 56 in the housing 2 of the brake hydraulic booster 1 in which the lever 27 and the like are housed is always connected to the hydraulic booster reservoir through the passage hole 57 and the passage hole 18, and is always It is kept at atmospheric pressure.

In the brake hydraulic booster 1 of the first example having the above-described structure, when the hydraulic pressure source is normal and the brake is not operated, the input piston 3 and the input shaft 4 are moved to the positions shown in FIGS. Since the lever 27 is also at the non-operating position as shown in the retreat limit position, the control valve 8 is in the non-operating state as shown above, and the hydraulic pressure supply valve is closed and the hydraulic pressure discharge valve is open. Further, since the radial hole 4e and the annular groove 5e are connected as shown, the reaction force chamber 58 is connected to the chamber 56 which is always connected to the reservoir, and is at atmospheric pressure.
Further, the shut-off valve 67 is opened as shown, and the reaction force chamber 58 is connected to the liquid storage chamber 75. Further, an electromagnetic solenoid 8
0 is not energized and its movable plunger 80a is not substantially energizing the valve spool 10.

Also, the master cylinder 33 does not operate,
As shown in FIG. 1, the primary piston 37 is the piston 5
Is in the inoperative position of the retreat limit abutting on the front end of the vehicle. At this time, as shown in FIG. 3, the radial hole 50 of the primary piston 37 is located behind the second cup seal 40, and the primary chamber 44 has the radial hole 50, the axial hole 36a, and the circumferential groove 3.
6b, inclined hole 36c, radial hole 34a of housing 34
Through the reservoir 51 for the master cylinder. Further, the radial hole 52 of the secondary piston 38 is located behind the fifth cup seal 43 and
Is a radial hole 52 and two radial passage holes 35a, 34b.
And the reservoir 10. Therefore, no master cylinder pressure is generated in the primary chamber 44 and the secondary chamber 47.

When the brake is operated, an input based on the pedal depression force is applied to the input piston 3 and the input shaft 4 by depressing the brake pedal, and the input piston 3 and the input shaft 4 move forward. At this time, the retainer portion 62 does not follow the forward movement of the input piston 3 and the input shaft 4 because the long hole 62a and the engaging pin 27a are engaged in the front-rear direction. Increase. The increased biasing force of the return spring 31 is transmitted to the lever 27 by the longitudinal engagement between the elongated hole 62a and the engagement pin 27a, and the lever 27 rotates counterclockwise about the first support pin 38. I do. The counterclockwise rotation of the lever 27 causes the valve spool 10 to move the movable plunger 80 of the electromagnetic solenoid 80 through the valve operating member 29.
Move forward while pressing a. At this time, the electromagnetic solenoid 8
Since 0 is not excited, the movable plunger 80a moves forward without resistance. Then, the first annular groove 25 is shut off from the third radial hole 13 to close the hydraulic pressure discharge valve, and the second annular groove 26 is connected to the fourth radial hole 14 to open the hydraulic pressure supply valve, and the accumulator is opened. Is supplied to the power chamber 6.

The hydraulic pressure introduced into the power chamber 6 is
Is introduced into the first annular groove 25 through the passage holes 21 and 20 and the second radial hole 12. The hydraulic pressure introduced into the first annular groove 25 acts on the small-diameter and large-diameter spool portions 10a and 10b having different pressure receiving areas as described above.
The valve spool 10 is biased in a direction in which the hydraulic pressure supply valve is closed and the hydraulic pressure discharge valve is opened.

On the other hand, when the input shaft 4 moves forward, the radial hole 4e and the annular groove 5e are immediately shut off, so that the reaction force chamber 58 is shut off from the chamber 56, that is, the reservoir. Therefore, the liquid in the reaction force chamber 58 is discharged to the liquid storage chamber 75 through the inclined hole 5g, the passage hole 2d, the open shutoff valve 67, and the passage hole 79 as the input shaft 4 advances. You. For this reason,
The simulator piston 76 moves leftward to effectively contain the liquid discharged from the reaction force chamber 58, and the stroke of the input shaft 4 is secured. Then, the spring force of the litter spring 31, that is, the input applied to the input piston 3, the spring force of the spool return spring 32, and the first annular groove 25
The valve spool 10 is controlled such that the urging force of the valve spool 10 due to the hydraulic pressure is balanced. By controlling the balance of the valve spool 10 in this manner,
The hydraulic pressure in the power chamber 6 becomes a hydraulic pressure according to the input of the input shaft 4, that is, the pedaling force, and the brake hydraulic booster 1 enters the intermediate load state. As a result, the output of the brake fluid pressure booster 1 becomes the magnitude of the input at this time, that is, the magnitude obtained by boosting the depression force of the brake pedal. That is, the hydraulic pressure of the power chamber 6, that is, the output of the brake hydraulic booster 1 is
, That is, according to the pedal stroke.

Further, the hydraulic pressure of the reaction force chamber 58 is equal to the first and second hydraulic pressures.
The hydraulic pressure acts on the front end of the input shaft 4 in the backward direction, and is transmitted to the driver via the brake pedal as a reaction force. . In that case, litter spring 3
Since the spring force of No. 1 is in accordance with this reaction force, the valve spool 10 is also controlled in accordance with this reaction force. As a result, the hydraulic pressure introduced into the power chamber 6 is controlled by the reaction force of the stroke simulator 68. Become so.

The hydraulic pressure introduced into the power chamber 6 acts on the rear end face of the primary piston 37, and the primary piston 37 moves forward. As the primary piston 37 advances, the radial hole 50 passes through the second cup seal 40, and a master cylinder pressure is generated in the primary chamber 44. Furthermore,
Due to the master cylinder pressure generated in the primary chamber 44 and the spring force of the primary return spring 46, the secondary piston 38 advances and its radial hole 52 passes through the fifth cup seal 43, and the secondary cylinder 47 also applies the master cylinder pressure. Occurs. Then, the master cylinder pressure generated in the primary chamber 44 is introduced into both wheel cylinders of one system through the primary output port 54, and
The master cylinder pressure generated in the secondary chamber 47 is introduced from the secondary output port 5 to both wheel cylinders of the other system, and the two systems of brakes operate. At this time,
The master cylinder pressures of the primary chamber 44 and the secondary chamber 47 are the same, the same hydraulic pressure is supplied to each of the two wheel cylinders, and the two systems have the same brake hydraulic pressure. . This brake fluid pressure has a magnitude obtained by boosting the depression force of the brake pedal.

When the brake pedal is released to release the brake operation, the input shaft 4 moves backward. Then, the spring force of the return spring 31 decreases, the lever 27 rotates clockwise about the first support pin 38, and the valve operating member 29 retreats. Thus, the second annular groove 26 is shut off from the fourth radial hole 14 to close the hydraulic pressure supply valve, and the first annular groove 25 is connected to the third radial hole 13 to open the hydraulic pressure discharge valve. Therefore, the hydraulic fluid in the power chamber 6 is discharged to the reservoir for the hydraulic booster through the hydraulic pressure discharge valve, and the hydraulic pressure in the power chamber 6 decreases. Further, the liquid from the liquid storage chamber 75 is returned to the reaction force chamber 58 by the retreat of the input shaft 4.

When the fluid pressure in the power chamber 6 decreases, the primary piston 37 is actuated by the master cylinder pressure in the primary chamber 44 and the spring force of the primary return spring 46.
Retreats. With the retraction of the power piston 5, the lever 2
Reference numeral 7 rotates counterclockwise about the second support pin 30.
Further, since the master cylinder pressure in the primary chamber 44 decreases due to the retraction of the primary piston 37, the secondary piston 38 is reduced by the master cylinder pressure in the secondary chamber 47 and the spring force of the secondary return spring 49.
Also retreat. With the retraction of the primary piston 37 and the secondary piston 38, the radial hole 50 and the radial hole 52 are respectively connected to the second cup seal 40 and the fifth cup seal 40.
Since it passes through the cup seal 43 and is located again behind the second cup seal 40 and the fifth cup seal 43, both the primary chamber 44 and the secondary chamber 33 communicate with the master cylinder reservoir 10 again. For this reason, the hydraulic fluid of the wheel cylinders of both systems is discharged to the master cylinder reservoir 10 through the primary chamber 44 and the secondary chamber 47, respectively.

When the input of the input piston 3 disappears, the power chamber 6
When the hydraulic pressure reaches the atmospheric pressure, the primary piston 37 is in the non-operation position, and the secondary piston 38 is also in the non-operation position, so that the master cylinder 33 does not generate the master cylinder pressure. Thereby, the brakes of both brake systems are quickly released. At this time, the radial hole 4e
And the annular groove 5e are connected again, the reaction force chamber 58 is connected to the reservoir via the chamber 56, and the liquid pressure in the reaction force chamber 58 becomes atmospheric pressure.

When the brake is operated, the pedaling force of the brake pedal is greatly increased, and the valve operating member 29 of the control valve 8 and the valve spool 10 are largely advanced. When the hydraulic pressure supply valve is opened to the maximum, the hydraulic pressure of the power chamber 6 is reduced. The pressure becomes equal to the pressure of the accumulator and does not increase any more, and the brake hydraulic booster 1 is in the full load state. In such a full load state of the brake hydraulic pressure booster 1, since the hydraulic pressure in the power chamber 6 is constant, further movement of the primary piston 37 due to the hydraulic pressure in the power chamber 6 stops. In the brake hydraulic booster 1 of the first example, the input shaft 4 cannot contact the primary piston 37 even if the input shaft 4 further strokes due to the input rise in the full load operating state. Therefore, at the time of full load operation, the primary piston 37 does not advance even if the input increases, and the master cylinder pressure does not increase more than the hydraulic pressure of the power chamber 6 at the time of full load operation.

Further, when the brake hydraulic booster 1 is operated,
Since the hydraulic pressure introduced into the power chamber 6 also acts on the power piston 5, the power piston 5 is
Does not move while being in contact with the second step portion 2b.
Therefore, the lever support portion 5a of the power piston 5
In addition, the position of the rotation fulcrum of the lever 27, which is swingably supported by the first support pin 28, does not move and is kept constant regardless of the stroke of the input shaft 4.

If a hydraulic pressure source such as a pump or an accumulator fails, the hydraulic pressure from the accumulator is not introduced into the power chamber 6 at the time of the brake operation. At this time, the ball valve 71 of the shut-off valve 67 has a valve seat as described above. 69 and shut off valve 6
7 is closed, and the reaction force chamber 58 is shut off from the liquid storage chamber 75.
In this state, when the brake pedal is depressed and the input shaft 4 moves forward to cut off the radial hole 4e and the annular groove 5e as described above, the reaction force chamber 58 is sealed. Then, since the input shaft 4 and the power piston 5 operate integrally, the power piston 5 also advances with the advance of the input shaft 4, and the power piston 5 pushes the primary piston 37 to advance. As a result, the master cylinder 33 generates the master cylinder pressure, so that the brake of the two-brake system operates even when the hydraulic pressure source fails.

By the way, in the brake hydraulic booster 1 of the first example, by operating the electromagnetic solenoid 80 in the normal operation state, the hydraulic pressure of the power chamber 6 can be controlled regardless of the input. Has become. That is, when the electromagnetic solenoid 80 is excited during the normal operation, the movable plunger 80a of the electromagnetic solenoid 80 operates and presses the valve spool 10 in the non-operation direction.
Is pushed back in the non-operation direction. Then, the first annular groove 25
Is connected to the third radial hole 13, so that the hydraulic pressure in the power chamber 6 is reduced and the master cylinder pressure is reduced.

At this time, the above-mentioned hydraulic pressure of the first annular groove 25 acts on the valve spool 10 in the non-operating direction, the combined force of the spring force of the spool return spring 32 and the electromagnetic force of the electromagnetic solenoid, and the input shaft 4. The valve spool 10 is controlled such that the spring force of the return spring 31 according to the input stroke of the valve spring is balanced, so that the hydraulic pressure in the power chamber 6 causes the electromagnetic force of the electromagnetic solenoid 80 to move the valve spool 10 in the non-operating direction. It decreases as much as it is added. Therefore, by controlling the supply current to the electromagnetic solenoid 80 and variously setting the electromagnetic force, it is possible to arbitrarily reduce the hydraulic pressure of the power chamber 6 and the master cylinder pressure. When this pressure reduction control is performed, the spring force of the return spring 31 of the input shaft 4 does not change, so that the input of the input shaft 4 and the input stroke do not change. As described above, even if the pressure reduction control of the hydraulic pressure in the power chamber 6 is performed, the influence does not occur on the input side.

As described above, according to the brake fluid pressure generating device 1 of the first example, the spring force of the return spring 31, that is, the input applied to the input piston 3, the spring force of the spool return spring 32, and the first annular shape Groove 25
Since the valve spool 10 is controlled so that the urging force of the valve spool 10 due to the hydraulic pressure is balanced and the stroke simulator is built in, the input side and the output side of the brake hydraulic booster 1 are separated. And a small-diameter spool portion 10 of the valve spool 10.
a and the spring force of the spool return spring 32 are variously set so as not to affect the output side of the brake hydraulic pressure booster 1 and to have the stroke characteristic on the input side. Can be changed in various ways.

Further, by controlling the supply current to the electromagnetic solenoid 80, the hydraulic pressure of the power chamber 6 during operation, that is, the master cylinder pressure can be reduced in accordance with the supply current. By appropriately setting, the pressure reduction control of the master cylinder pressure can be arbitrarily performed. Furthermore, since the stroke simulator 68 is only incorporated in the brake hydraulic booster 1 and a separately formed stroke simulator is not provided externally, the hydraulic booster 2 can be formed compact.

Further, since the stroke simulator 68 is simply incorporated in the conventional lever-type brake hydraulic booster, the conventional lever-type brake hydraulic booster 1
Can be simply changed, and the conventional lever type brake hydraulic booster 1 can be simplified,
Cost can be reduced.

FIG. 4 is a partial sectional view similar to FIG. 2, showing a second example of the embodiment of the present invention. In the following description of each embodiment of the present invention, the same components are denoted by the same reference numerals. As shown in FIG. 4, the brake hydraulic booster 1 of the second example does not include the electromagnetic solenoid 80 in the brake hydraulic booster 1 of the first example. Other configurations of the brake hydraulic booster 1 of the second example and the master cylinder 33 are the same as those of the first example.

Therefore, in the brake hydraulic booster 1 of the second example having such a configuration, the pressure reduction control of the power chamber 6 by the electromagnetic solenoid 80 of the first example, that is, the pressure reduction control of the master cylinder pressure is performed. Absent. The other operation and effect of the brake hydraulic booster 1 of the second example and the operation and effect of the master cylinder 33 are the same as those of the first example.

FIG. 5 is a partial sectional view similar to FIG. 2, showing a third embodiment of the present invention. In the first example described above, the valve spool 10 is pushed in the non-operation direction by the electromagnetic force of the electromagnetic solenoid 80.
In the example brake hydraulic booster 1, the electromagnetic solenoid 80
The valve spool 10 is pulled in the operation direction by the electromagnetic force. Therefore, in the movable plan of the electromagnetic solenoid 80, the valve 80a and the valve spool 10 are connected so as to be engaged with each other in the pulling direction. Other configurations of the brake hydraulic booster 1 of the third example and the master cylinder 33 are the same as those of the first example.

In the brake hydraulic booster 1 of the third example having the above-described structure, when the electromagnetic solenoid 80 is excited during the normal braking operation, the movable plunger 80a moves the valve spool 10 in the operating direction. To pull.
Therefore, the valve spool 10 moves to the left, so that the output pressure of the control valve 8 increases, and the hydraulic pressure of the power chamber 6 increases. Therefore, the master cylinder pressure is increased.

At this time, the above-described hydraulic pressure of the first annular groove 25 acts on the valve spool 10 in the non-operating direction and the resultant force of the spool return spring 32, the electromagnetic force of the electromagnetic solenoid and the input shaft 4. Since the valve spool 10 is controlled so that the resultant force of the return spring 31 according to the input stroke is balanced, the hydraulic pressure in the power chamber 6 causes the electromagnetic force of the electromagnetic solenoid 80 to move the valve spool 10 in the operating direction. As you add, it will rise. Therefore, by controlling the supply current to the electromagnetic solenoid 80 and variously setting the electromagnetic force, the power room 6
Pressure control of the hydraulic pressure and the master cylinder pressure can be arbitrarily performed. When the pressure increase control is performed, the spring force of the return spring 31 of the input shaft 4 does not change, so that the input and the input stroke of the input shaft 4 do not change. As described above, even if the pressure increase control of the hydraulic pressure in the power chamber 6 is performed, the input side has no influence.

When the normal brake is inactive,
When the electromagnetic solenoid 80 is excited, the movable plunger 8
0a pulls the valve spool 10 in the operating direction. Accordingly, the control valve 8 operates to generate an output pressure corresponding to the exciting force of the electromagnetic solenoid 80. When the output pressure is supplied to the power chamber 6, the master cylinder 33 operates to generate the master cylinder pressure, and the brake operates. As described above, when the electromagnetic solenoid 80 is excited in the non-operating state of the normal brake, automatic braking can be performed. The other operational effects of the brake hydraulic booster 1 of the third example and the operational effects of the master cylinder 33 are as follows.
Same as the example.

FIG. 6 is a partial sectional view, similar to FIG. 2, showing a fourth embodiment of the present invention. In each of the above examples, the normally closed control valve in which the control valve 8 is closed when the hydraulic pressure supply valve is not operated is used. However, in the brake hydraulic booster 1 of the fourth example, the control valve In FIG. 8, a normally open control valve having a non-operating valve open is used. That is, in the first example shown in FIGS. 1 and 2 described above, the fourth and fifth radial holes 14 and 15 of the valve sleeve 9 are, as shown in FIG. It is provided at the same position in the direction. Further, the second annular groove 26 is always connected not only to the fifth radial hole 15 but also to the fourth radial hole 14. Furthermore, the third radial hole 13 of the valve sleeve 9
The first annular groove 25 and the first annular groove 25 are connected with a relatively large passage area when not in operation as compared with the first example. Furthermore, this fourth
In the example, the accumulator is not used for the hydraulic pressure source,
Only a pump (not shown) is used. In the brake hydraulic booster 1 of the fourth example, the hydraulic pressure of the hydraulic pressure source received by the valve operating piston 73 of the shut-off valve 67 is the pump discharge pressure.

The other structure of the brake hydraulic booster 1 of the fourth example and the master cylinder 33 are the same as those of the first example. Therefore, when the control valve 8 is not operated, the power chamber 6 is not only connected to the reservoir for the brake hydraulic booster but also connected to the pump.
Is a normally open control valve.

In the brake hydraulic booster 1 of the fourth example having the above-described structure, when the pump is driven in the non-operating state of the brake, the pump discharge liquid from the hydraulic booster reservoir passes through the passage. Hole 23, fourth radial hole 14, second annular groove 26, passage hole 22, passage hole 21, passage hole 20, second radial hole 12, first annular groove 25, third radial hole 13, and passage The fluid is returned to the reservoir for the hydraulic booster through 18. At this time, since the first annular groove 25 and the third radial passage 13 are connected with a large passage area, the recirculating pump discharge liquid is not restricted at all, and no hydraulic pressure is generated.

When the brake is operated, when the input shaft 4 moves forward, the lever 27 rotates counterclockwise as in the above-described embodiments, and the valve spool 10 moves forward. Then, the first
Since the area of the passage between the annular groove 25 and the third radial passage 13 is gradually reduced, the pump discharge liquid flowing back is restricted,
Hydraulic pressure is generated in the annular groove 25. This hydraulic pressure is also introduced into the passage hole 22, and therefore also into the power chamber 6 as in the case of the first example. Other functions and effects of the brake hydraulic booster 1 of the fourth example are substantially the same as those of the first example.

Although the normally open control valve is applied to the brake hydraulic booster 1 of the first example, it can be applied to the brake hydraulic booster 1 of another example. In each of the above-described examples, the hydraulic booster of the present invention is described using a lever type hydraulic booster using a lever as a hydraulic booster. It can also be applied to a hydraulic booster that does not use a lever. Further, in each of the above-described embodiments, the hydraulic booster of the present invention is applied to the brake hydraulic booster, but the present invention can be applied to other hydraulic boosters other than the brake. Further, in each of the above-described embodiments, the hydraulic booster of the present invention is applied to the brake hydraulic booster, but the present invention can be applied to other hydraulic boosters other than the brake.

[0071]

As is apparent from the above description, according to the hydraulic booster of the present invention, the hydraulic fluid controlled by the control valve is generated as an output, and the actuator is operated by the hydraulic pressure of the output. Since the operation is performed directly, the input side and the output side can be operated separately. And since the hydraulic booster of the present invention is provided with the stroke simulator, the input stroke of the input member can be secured, and it is not affected by the control situation on the output side prior to the actuator,
Various input strokes of the input member can be set.

During the operation of the hydraulic booster, the hydraulic pressure control means controls the hydraulic pressure for operating the actuator, that is, the output of the hydraulic booster, regardless of the input of the input member. Therefore, for example, a hydraulic pressure booster such as a pressure reduction control of the hydraulic pressure when the regenerative brake is operated in the regenerative brake cooperative system as described above or a hydraulic pressure increase control in the brake assist system when the brake assist is performed. It is possible to easily and flexibly cope with a system that requires control of the hydraulic pressure during operation of irrespective of the input of the input member.

Further, in the hydraulic booster in a state where the operation by the input member is not performed, the hydraulic fluid pressure control means can control the hydraulic pressure for operating the actuator regardless of the operation of the input member. Become. This makes it possible to easily and flexibly cope with a system that requires automatic operation control, such as the above-described automatic brake control such as the inter-vehicle control brake, the collision avoidance brake control, or the traction control brake control. Become.

Further, the control valve of the conventional hydraulic booster can be used as the control valve with almost no change.
ADVANTAGE OF THE INVENTION The hydraulic booster of this invention can be inexpensive with a simple structure, without using a special part. Further, when the hydraulic pressure source has failed, the actuator is operated by moving the input member forward, so that the actuator can be reliably operated even when the hydraulic pressure source has failed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a brake hydraulic booster to which a first embodiment of a hydraulic booster according to the present invention is applied.

FIG. 2 is a partially enlarged sectional view of a control valve and a lever portion of the brake hydraulic booster shown in FIG.

FIG. 3 is a partially enlarged cross-sectional view of a master cylinder portion shown in FIG.

FIG. 4 is a partial sectional view showing a second example of the embodiment of the present invention.

FIG. 5 is a partial sectional view showing a third example of the embodiment of the present invention.

FIG. 6 is a partial sectional view showing a fourth example of the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Brake hydraulic booster, 2 ... Hydraulic booster housing, 3 ... Input piston, 4 ... Input shaft, 5 ... Power piston, 6 ... Power chamber, 8 ... Control valve, 9 ... Valve sleeve,
9a: step, 10: valve spool, 27: lever, 2
8 First support pin, 29 Valve actuating member, 30 Second support pin, 31 Return spring, 31a First return spring, 31b Second return spring, 32
... Spool return spring, 33 ... Master cylinder, 37 ... Primary piston, 38 ... Second piston, 58 ... Reaction chamber, 67 ... Shutoff valve, 68 ... Stroke simulator, 75 ... Liquid storage chamber, 76 ... Simulator piston, 80 ... Electromagnetic solenoid

Claims (4)

[Claims] An input member that strokes with an input applied during operation, and an operation that is controlled by the input member to control a hydraulic pressure of a hydraulic pressure source in accordance with an operation amount of the input member to operate an actuator. A control valve for generating hydraulic pressure, a power chamber in which the operating hydraulic pressure is introduced to operate the actuator, and a hydraulic pressure corresponding to the input of the input member is generated, and the hydraulic pressure At least a reaction force chamber in which a reaction force is applied to the input member, wherein the working fluid pressure acts on the control valve in a non-operating direction, and the control valve and the input member An elastic member is disposed between the control member and an operating force of the elastic member in accordance with an operation amount of the input member, which acts on the control valve in an operating direction. Working force by hydraulic pressure and work by the elastic member The reaction chamber is connected to a stroke simulator for securing a stroke of an input member so as to balance communication with a force so as to balance the force, and the reaction pressure chamber is connected to the stroke simulator in a disconnectable manner. In the normal state, the reaction force chamber is connected to the stroke simulator to secure the stroke of the input member, and when the hydraulic pressure source fails, the reaction force chamber is shut off from the stroke simulator to be sealed. Thus, the actuator is actuated by a stroke of the input member. 2. The control valve according to claim 1, wherein the control valve is operated by an operating force of the elastic member in an operating direction and the operating hydraulic pressure is operated in a non-operating direction. A valve sleeve fixed to a housing of a force device, wherein the valve spool is configured such that the input member is configured such that an operating force of the hydraulic fluid acting on the valve spool and an operating force of the elastic member are balanced. 2. The hydraulic booster according to claim 1, wherein the hydraulic booster is adapted to move relative to the valve sleeve in response to an input from the valve sleeve. 3. A lever is provided between the elastic member and the control valve, the lever being turned by an acting force of the elastic member in accordance with an operation amount of the input member to act on the control valve in an operating direction. The position of the fulcrum of rotation of the lever is constant irrespective of the stroke of the input member, and the control valve is configured to balance the acting force by the hydraulic pressure and the acting force by the rotation of the lever. The hydraulic booster according to claim 1 or 2, wherein the operation is controlled in accordance with the input member. 4. An electromagnetic solenoid for generating an urging force for urging the control valve in at least one of an operation direction and a non-operation direction, thereby controlling the hydraulic fluid pressure regardless of an input of the input member. 2. The method according to claim 1, wherein
Or the hydraulic booster according to 2.