JP2000177576A - Fluid pressure generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further effectively shorten the total length of an integral assembly of a hydraulic booster and a master cylinder, and to reliably reduce a fluctuation in a lost stroke of the master cylinder. SOLUTION: A part of a primary piston 43 of a master cylinder 3 is arranged in a housing 4d of a hydraulic booster, and a small diameter part 12b of a power piston 12 of the hydraulic booster is loosely fitted in a hole of a rear end part of the primary piston 43. An adjusting member 49 is arranged on the tip of the small diameter part 12b of this power piston 12. This adjusting member 49 adjusts respective strokes of both pistons 43, 44 to a prescribed value until master cylinder pressure is generated in a primary chamber 52 and a secondary chamber 55 when respective radial directional holes 58, 62 of the primary and secondary pistons 43, 44 respectively pass through third/fifth cup seals 47, 51 from a non-actuated position, in other words, adjusts a lost stroke of the master cylinder 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic booster for boosting an operating force of an operating means to a predetermined magnitude by a hydraulic pressure and outputting the boosted force, and a hydraulic booster operated by the output of the hydraulic booster It belongs to the technical field of a hydraulic pressure generator configured by integrally assembling a master cylinder that generates a master cylinder pressure, and in particular, a hydraulic booster and a master cylinder that are formed separately from each other are integrally formed. The present invention belongs to the technical field of a hydraulic pressure generator for shortening the total stroke of an integrated assembly formed by connection and shortening a loss stroke of a piston of a master cylinder.

[0002]

2. Description of the Related Art For example, in a brake fluid pressure generating device of an automobile, a brake fluid pressure booster for boosting the pedal depression force of a brake pedal to a predetermined magnitude by a fluid pressure and outputting the boosted fluid has been known. In many cases, a master cylinder that generates a master cylinder pressure by being actuated by the output of the pressure booster is formed separately, and these are integrally connected to form an integrated assembly. This brake fluid pressure generating device is capable of obtaining a large braking force with a small brake pedal depression force, thereby ensuring braking and reducing the driver's labor.

As an example of such a brake hydraulic pressure booster in such a brake hydraulic pressure generator, Japanese Utility Model Application Laid-Open No. 7-315 is disclosed.
There is a brake hydraulic pressure booster disclosed in Japanese Patent Publication No. 40-240. The brake hydraulic booster disclosed in this publication is formed separately from a master cylinder, houses a power piston in a housing for the hydraulic booster, and outputs the output of the power piston to the hydraulic booster. The output is made from the inside of the housing through an output shaft extending through the housing and extending outside the housing.

A master cylinder disposed in front of the brake hydraulic booster is operated by the output of the brake hydraulic booster to generate a master cylinder pressure, and the brake is operated by the master cylinder pressure. It is supposed to be.

[0005]

Conventionally, a brake hydraulic booster and a master cylinder have a structure in which a master cylinder housing is integrally connected to a front end of a hydraulic booster housing. A master cylinder piston housed in the master cylinder housing is actuated by an output shaft of a brake hydraulic booster extending from the hydraulic booster housing to the master cylinder housing, A master cylinder pressure is generated.

For this reason, the brake fluid pressure generating device, which is an integrated assembly of the brake fluid pressure booster and the master cylinder, has a relatively long overall length. Also, since the power piston of the brake hydraulic booster and the master cylinder piston of the master cylinder are simply connected by the output shaft, the time between when the master cylinder piston actually generates the master cylinder pressure from its non-operating position is obtained. The loss stroke of the brake hydraulic pressure booster and the master cylinder have various variations due to the integrated assembly.

The present invention has been made in view of such circumstances, and an object of the present invention is to make it possible to more effectively shorten the total length of an integrated assembly of a hydraulic booster and a master cylinder, and to reduce the length of a master cylinder. An object of the present invention is to provide a hydraulic pressure generator capable of surely reducing variation in a loss stroke of a cylinder.

[0008]

In order to solve the above-mentioned problems, a first aspect of the present invention provides a housing for a hydraulic booster,
A power chamber provided in the hydraulic booster housing and supplied with a hydraulic pressure from a hydraulic pressure source, provided in the hydraulic booster housing and operated by the hydraulic pressure of the power chamber. A power piston that outputs power, an input shaft that operates with an input applied during operation, and an input that is controlled by the input shaft and controls supply and discharge of hydraulic pressure from a hydraulic pressure source to the power chamber. A hydraulic booster having at least a control valve for generating a power chamber pressure corresponding to the input of the shaft, and a hydraulic booster formed separately from the hydraulic booster housing and in front of the hydraulic booster housing Master cylinder housing integrally connected to the unit, a master cylinder piston provided in the master cylinder housing and operated by the output of the power piston, and operation of the master cylinder piston A master cylinder having at least a master cylinder pressure chamber in which a master cylinder pressure is generated and the master cylinder pressure disappears when the master cylinder piston is not operated, and a part of the master cylinder piston is provided with the hydraulic pressure booster. A front end of the power piston is loosely fitted in a hole formed in a rear end of the master cylinder piston, the power piston and the master cylinder piston being disposed in a housing for the device. And an adjusting member for adjusting the stroke from the inoperative position of the master cylinder piston to the start of generation of the master cylinder pressure to a predetermined value. The invention according to claim 2 is characterized in that the power chamber pressure is supplied to one system and the master cylinder pressure is supplied to another system.

The invention of claim 3 further provides a housing for the hydraulic booster, a power chamber provided in the housing for the hydraulic booster and supplied with hydraulic pressure from a hydraulic pressure source, A power piston provided in the booster housing and operated by the hydraulic pressure of the power chamber to output, an input shaft operated by an input applied at the time of operation, and an operation controlled by the input shaft and provided to the power chamber. A hydraulic booster including at least a control valve that controls supply and discharge of hydraulic pressure from a hydraulic pressure source to generate a power chamber pressure in the power chamber in accordance with an input of the input shaft; A master cylinder housing formed separately from the device housing and integrally connected to a front portion of the hydraulic booster housing, provided in the master cylinder housing and operated by the output of the power piston Do A master cylinder pressure chamber for generating a master cylinder pressure when the master cylinder piston is operated and for eliminating the master cylinder pressure when the master cylinder piston is not operated, wherein the master cylinder piston is a primary piston And the secondary piston, and the master cylinder hydraulic chamber is composed of a primary chamber and a secondary chamber, and the primary piston is operated by the output of the power piston to generate a master cylinder pressure in the primary chamber. The secondary piston is constituted by a master cylinder which is operated by a master cylinder pressure generated in the primary chamber to generate a master cylinder pressure in the secondary chamber, and a part of the primary piston is a hydraulic booster. A front end of the power piston is loosely fitted in a hole formed at a rear end of the primary piston, and the power piston and the primary piston are further disposed between the power piston and the primary piston. An adjusting member for adjusting a stroke from at least the inoperative position of the primary piston to the start of generation of the master cylinder pressure to a predetermined value is provided therebetween.

Further, in the invention according to claim 4, the power chamber pressure and the master cylinder pressure of one of the primary chamber and the secondary chamber are supplied to one system, and one of the primary chamber and the secondary chamber is provided. It is characterized in that the other master cylinder pressure is supplied to another system.

Further, in the invention according to claim 5, the adjusting member is fitted into a hole formed at the tip of the power piston and is prevented from falling out of the hole by an elastic member. The member is characterized in that adjustment members of various lengths are prepared.

[0012]

In the hydraulic pressure generating apparatus according to the present invention having the above-described structure, a part of the master cylinder piston or the primary piston of the master cylinder is disposed in the hydraulic booster housing, and the master cylinder piston and the primary piston are arranged in the housing. The front end of the power piston is inserted into a hole provided at the rear end of the cylinder piston or the primary piston. Therefore, the total length of the integrated assembly of the hydraulic booster and the master cylinder is effectively reduced.

[0013] Further, an adjusting member interposed between the power piston and the master cylinder piston or the primary piston adjusts a loss stroke until a master cylinder pressure of the master cylinder piston or the primary piston is generated to a predetermined value. . As a result, variation in the loss stroke of the master cylinder is reduced.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a brake fluid pressure generator to which an embodiment of a fluid pressure generator according to the present invention is applied, FIG. 2 is a partially enlarged sectional view of FIG. 1, and FIG. 3 is a brake fluid shown in FIG. FIG. 4 is a partially enlarged sectional view of FIG. 1 showing a reaction force piston used in the pressure generating device.

As shown in FIGS. 1 to 4, the brake hydraulic pressure generating device 1 of this embodiment has a hydraulic booster 2 and a master cylinder 3 which is operated by the output of the hydraulic booster 2. Although provided on the body, the hydraulic booster 2 and the master cylinder 3 are integrally connected to each other to form an integrated assembly. The housing 4 of the integrated assembly of the hydraulic booster 2 and the master cylinder 3 includes a housing front portion (left portion in FIG. 1) 4a and a housing first intermediate portion 4
b, a housing second intermediate part 4c and a housing rear part (right part in FIG. 1) 4d are divided into four parts, and the housing first intermediate part 4b is fitted in a hole of the housing front part 4a in a liquid-tight manner. The intermediate portion 4c is fitted and fixed in a hole of the housing front portion 4a in a liquid-tight manner, and the housing front portion 4a and the housing rear portion 4d are connected to each other. In this case, a housing for the hydraulic booster 2 is constituted by the housing rear part 4d, and the housing front part 4a and the first and second intermediate parts 4b and 4c form
A housing for the master cylinder 3 is configured.

The hydraulic booster 2 will be described. A first opening at the right end of the housing 4 at the rear portion 4d of the housing 4 will be described.
The first hole 5 is formed continuously with the left end of the first hole 5.
A second hole 6 having a diameter smaller than the diameter of the hole 5 is formed, a third hole 7 is formed in the housing second intermediate portion 4c, and a fourth hole 8 is formed in the housing first intermediate portion 4b. And a fifth hole 9 is further formed in the housing front part 4a. These first to fifth holes 5, 6, 7, 8, 9 are formed as one stepped hole, of which the second to fourth holes 6, 7, 8 are set to have the same diameter. ing. First
The right end of the hole 5 is closed by a plug 10 in a liquid-tight manner.
d through the first hole 5 and the second hole 5
It is in contact with the step of the hole 6 and is fixed to the housing 4.

A power piston 12 of the hydraulic booster 2 is provided in the second hole 6.
Is configured as a stepped piston having a large-diameter portion 12a on the rear side and a small-diameter portion 12b on the front side.
It is fitted in a liquid-tight and slidable manner by an O-ring provided on the outer peripheral surface of the large diameter portion 12a.

The power piston 12 has a sixth hole 13 opening at the rear end of the power piston 12 and a sixth hole 1.
A third hole 14 having a diameter smaller than the diameter of the sixth hole 13 is formed in the left end of the third hole 3 and is closed at the left end, and these sixth and seventh holes 13 and 14 are formed. It is formed as one stepped hole. A cylindrical valve seat member 15 is disposed in the seventh hole 14 in a liquid-tight manner. The flange portion 15 a of the valve seat member 15 is provided with a cylindrical fixing member 16 fitted in the sixth hole 13. The power piston 12 is screwed into the right end of the power piston 12 through a nut 17.
It is fixed to. A predetermined number of radial grooves 15b are formed in the rear end face of the flange portion 15a of the valve seat member 15.

In the seventh hole 14, a valve body 19 supporting a ball valve 18 is slidably provided.
Is constantly urged by the valve spring 20 in the direction in which the ball valve 18 is seated on the first valve seat 15 c of the valve seat member 15. In addition, a cylindrical member 21 having a second valve seat 21a at the distal end capable of contacting the ball valve 18 is provided in the axial hole 15d of the valve seat member 15. This tubular member 21 is
The valve seat member 1 is fitted in an axial hole of a cylindrical stopper member 23 fitted and fixed to a front end of the input shaft 22.
It is fixed to the cylindrical stopper member 23 by a spring 24 contracted between the cylindrical member 5 and the cylindrical member 21. The input shaft 22 and the cylindrical stopper member 23 penetrate through the axial hole 10b of the cylindrical protrusion 10a of the plug 10. Further, the input shaft 22 penetrates the plug 10 in a liquid-tight and slidable manner,
The rear end of the input shaft 22 is connected to a brake pedal (not shown). As shown, the flange 23a of the cylindrical stopper member 23 is
By contacting the leading end 10c of the zero cylindrical protrusion 10a, the respective retreat limits of the cylindrical member 21, the input shaft 22, and the cylindrical stopper member 23 are respectively defined.

A cylindrical reaction force piston 25 slides between each of the outer circumferences of the input shaft 22 and the cylindrical stopper member 23 and the inner circumference of the axial hole 10b of the cylindrical projection 10a of the plug 10. Mated as possible. As shown in FIG. 3, a first flange portion 25a and a second flange portion 25b are provided at the left end of the reaction force piston 25 in FIG.
The left side of the first flange portion 25a is the cylindrical stopper member 2
3 can be brought into contact with each other, and when the flange 23a comes into contact, the reaction force piston 2
A stopper portion 25c for preventing the cylindrical stopper member 23 from retreating further is provided.

The right side of the second flange 25b is
When the reaction force piston 25 moves backward by a predetermined amount with respect to the power piston 12, the engagement portion 25d is engaged with the step 16a of the cylindrical fixing member 16. Further, the right end 25 e of the reaction force piston 25 can contact the step 22 a of the input shaft 22. The spring 2 is located between the second flange portion 25 b of the reaction force piston 25 and the cylindrical fixing member 16.
The second flange portion 25b of the reaction force piston 25 is normally operated by the spring force of the spring 26.
Is in contact with the rear surface of the flange portion 15a of the valve seat member 15.

Further, an input port 27 through which pressure fluid is introduced, and a passage hole 28 communicating the input port 27 with the second hole 6 are provided at a rear portion 4 d of the housing 4. An annular groove 29 communicating with the passage hole 28 is provided on the outer circumference of the power piston 1.
2, a passage hole 30 is formed to communicate between the annular groove 29 and the valve body 19 side of the seventh hole 14 from the valve seat member 15. The input port 27, the passage hole 28, the annular groove 29, and the passage hole 30 form a hydraulic pressure supply passage.

A power chamber 31 is formed in the second hole 6 between the plug 10 and the rear end of the power piston 12.
The power chamber 31 is always in communication with the axial hole 15d of the valve seat member 15. In the power chamber 31, a flange portion 23a of the cylindrical stopper member 23 and first and second flange portions 25a, 25b of the reaction force piston 25 are respectively located. An axial groove (not shown) is provided between the outer peripheral surface of the cylindrical protrusion 10 a of the plug 10 and the inner peripheral surface of the spring support of the cylindrical fixing member 16. The hydraulic fluid can flow freely on both axial sides. The power chamber 31 is always communicated with an output port (not shown) through a passage hole 32 formed in the housing 4, and the output port is connected to a wheel cylinder (not shown) in one of the two brake systems. Is always in communication.

Further, the axial holes 21b of the cylindrical member 21 opened at both left and right ends are formed with an axial passage hole 33 and a radial passage hole 34 formed in the input shaft 22, and an annular groove formed in the plug 10. 35 and radial passage hole 36, plug 10
An annular space 37 formed between the housing 4 and the housing 4 and an axial passage hole 38 formed in the housing rear portion 4d of the housing 4 always communicate with the outlet 39. The outlet 39 is shown in the drawing. It is always in communication with the reservoir for the hydraulic booster.

Further, although not shown, a hydraulic circuit connecting the input port 27 and the reservoir for the hydraulic booster is provided with a hydraulic pump and the hydraulic pump in the same manner as a conventional general hydraulic brake system. An accumulator is provided on the discharge side via a check valve. The accumulator always stores a predetermined pressure by the discharge pressure of the hydraulic pump, and the accumulated pressure of the accumulator is stored in the input port 2.
7 is always introduced.

When the brake is not operated without the brake pedal being depressed, the ball valve 18, the first valve seat 15c of the valve seat member 15, and the second valve seat 21a of the tubular member 21
The positional relationship is shown in FIG. 1 and FIG. That is, the ball valve 18 is seated on the first valve seat 15 c of the valve seat member 15 and the ball valve 18 is seated on the second valve seat 2 of the cylindrical member 21.
1a, and in this state, the passage hole 30 that is always in communication with the input port 27 and the axial hole 15 of the valve seat member 15.
d is shut off, and the cylindrical member 21 is always in communication with the axial hole 15 d of the valve seat member 15 and the discharge port 39.
And the axial hole 21b. Therefore, when the brake is not operated, the power chamber 31 is shut off from the hydraulic pump and the accumulator, and communicates with the reservoir for the hydraulic booster, so that no pressure fluid is supplied to the power chamber.

When the brake pedal is depressed, the input shaft 22 moves forward, the second valve seat 21a of the cylindrical member 21 comes into contact with the ball valve 18, and the ball valve 18 is moved to the second valve seat 21a. And the ball valve 18 is separated from the first valve seat 15c of the valve seat member 15, so that in this state, the axial hole 15d of the valve seat member 15 and the axial hole 21b of the tubular member 21 are shut off. At the same time, the passage hole 30 communicates with the axial hole 15d of the valve seat member 15. Therefore, at the time of the brake operation, the power chamber 31 is disconnected from the reservoir for the hydraulic booster, communicates with the hydraulic pump and the accumulator, and the pressure fluid of the accumulator is supplied to the power chamber 31. Thus, the ball valve 18, the valve seat member 1
5 of the first valve seat 15c and the second valve seat 21 of the cylindrical member 21
The control valve 40 of the hydraulic booster 2 that selectively switches and controls the power chamber 31 to either the hydraulic pressure source of the hydraulic pump and the accumulator or the reservoir for the hydraulic booster is constituted by a. Further, the power chamber 31 is provided with the power piston 1
2 is always in communication with a chamber 42 facing the left end of the valve body 19 through an axial passage hole 41 formed in the valve body 19.

On the other hand, the master cylinder 3 will be described. As shown in FIGS.
Is configured as a tandem master cylinder having a primary piston 43 and a secondary piston 44 having the same effective pressure receiving area.

As shown in FIGS. 2 and 4, the primary piston 43 has a second hole 6 in the housing rear portion 4d of the housing 4, a third hole 7 in the housing second intermediate portion 4c, and a second hole 6 in the housing first intermediate portion 4b. It is arranged in four holes 8. That is, a part of the primary piston 43 is disposed in a housing rear portion 4d which is a housing for the hydraulic booster 2. The primary piston 43 has a first cup seal 45 provided on the inner peripheral surface of the second hole 6 of the housing rear part 4d, and a second cup seal provided on the inner peripheral surface of the third hole 7 of the housing second intermediate part 4c. 46 and a third cup seal 47 provided between the first and second intermediate portions 4b and 4c and provided on the inner peripheral surface of the third hole 7 of the housing second intermediate portion 4c. The holes 6, 7, 8 are movably provided in these holes 6, 7, 8. The third cup seal 47 is
The liquid is prevented from flowing from the front side to the rear side, and the reverse flow is allowed.

The space between the outer peripheral surface of the primary piston 43 behind the first cup seal 45 and the inner peripheral surface of the second hole 6 of the housing rear part 4d is always in communication with the passage hole 38. In other words, in order to reduce the sliding resistance of the primary piston 43, a part of the passage that connects the outer peripheral surface of the primary piston 43 behind the first cup seal 45 to the reservoir for the hydraulic booster to make it atmospheric pressure is provided. , And also serves as a discharge passage of the hydraulic booster 2.

As described above, a part of the primary piston 43 is disposed in the housing rear portion 4d which is the housing of the hydraulic booster 2, and the first cup seal 45 is provided on the inner peripheral surface of the housing rear portion 4d of the housing 4. Is provided, and the outer peripheral surface of the primary piston 43 behind the first cup seal 45 is communicated with the atmosphere through the discharge passage of the hydraulic booster 2 so that the hydraulic booster 2 and the master cylinder are connected. 3 has been reduced in size.

An eighth hole 48 formed in the rear end of the primary piston 43 has a small diameter portion 12 of the power piston 12.
b is loosely fitted. An adjusting member 49 is provided at the distal end of the small-diameter portion 12b of the power piston 12, and the adjusting member 49 is fitted and fixed to a hole 12c formed at the center of the distal end of the small-diameter portion 12b. And an elastic member 49b, such as an O-ring or a rubber ring, which is externally fitted to the cylindrical member 49a to prevent the cylindrical member 49a from dropping out of the hole 12c. The adjusting member 49 abuts on the primary piston 43 of the master cylinder 3 to adjust the positions of the power piston 12, the primary piston 43, and the secondary piston 44. Specifically, the adjusting member 49 has a configuration in which the radial hole 58 of the primary piston 43 and the radial hole 62 of the secondary piston 44 pass through the third cup seal 47 and the fifth cup seal 51 from the inoperative position, respectively, as described later. Then, each stroke of the primary piston 43 and the secondary piston 44 until the master cylinder pressure is generated in the primary chamber 52 and the secondary chamber 55 is adjusted to a predetermined value, in other words, the loss stroke of the master cylinder 3 is adjusted. . Several types of adjusting members 49 having different axial lengths of the columnar members 49a are prepared, and they are selected according to the predetermined value of the stroke set in the brake fluid pressure generating device 1. The loss stroke of the master cylinder 3 is adjusted.

The secondary piston 44 is disposed in the fourth hole 8 of the housing first intermediate portion 4b of the housing 4 and the fifth hole 9 of the housing front portion 4a. The secondary piston 44 is disposed between the fourth cup seal 50 provided on the inner peripheral surface of the fourth hole 8 of the housing first intermediate portion 4b and the housing front portion 4a and the housing first intermediate portion 4b. A fifth cup seal 51 provided on the inner peripheral surface of the fifth hole 9 of the front portion 4a is provided in these holes 8, 9 in a liquid-tight and slidable manner. The fifth cup seal 51 prevents the flow of the liquid from the front side to the rear side and allows the reverse flow.

A primary chamber 52 is formed between the primary piston 43 and the secondary piston 44, and a primary return spring 54 whose maximum length is regulated by a primary spring retainer 53.
Has been curtailed. In a fifth hole 9 between the housing front part 4a of the housing 4 and the secondary piston 44, a secondary chamber 55 is formed, and a secondary return spring 57 whose maximum length is regulated by a secondary spring retainer 56 is formed. It has been curtailed. In this case, the spring force of the secondary return spring 57 is set to be larger than the spring force of the primary return spring 54.

At the front end of the primary piston 43, a radial hole 58 is formed. The radial hole 58 is a gap between the outer peripheral surface of the primary piston 43 and the inner peripheral surface of the third hole 7, It is possible to communicate with the master cylinder reservoir 61 through a passage hole 59 formed in the housing second intermediate portion 4c between the second and third cup seals 46 and 47, and a passage hole 60 formed in the housing front portion 4a. It has become. Then, in the illustrated inoperative position of the primary piston 43,
The radial hole 58 is located slightly behind the third cup seal 47. At this time, the primary chamber 52 communicates with the master cylinder reservoir 61, but when the primary piston 43 advances, the radial hole 58 becomes the third hole. When located in front of the cup seal 47, the primary chamber 52 and the master cylinder reservoir 61 are shut off in the direction from the primary chamber 52 to the master cylinder reservoir 61,
A master cylinder pressure is generated in the primary chamber 52.

A radial hole 62 is formed at the front end of the secondary piston 44.
Are the gap between the outer peripheral surface of the secondary piston 44 and the inner peripheral surface of the fourth hole 8, and the fourth and fifth cup seals 50 and 51.
Passage hole 6 drilled in the housing first intermediate portion 4b
3. It can communicate with the master cylinder reservoir 61 via a passage hole 64 formed in the front part 4a of the housing. When the secondary piston 44 is in the non-operating position shown in the drawing, the radial hole 62 is located slightly behind the fifth cup seal 51. At this time, the secondary chamber 55 communicates with the master cylinder reservoir 61. When the radial hole 62 is located forward of the fifth cup seal 51 by the advance of the secondary piston 44, the secondary chamber 55 and the reservoir 61 for the master cylinder are connected to the secondary chamber 55.
Is shut off in a direction toward the master cylinder reservoir 61, and a master cylinder pressure is generated in the secondary chamber 55.

The primary chamber 52 is connected to a wheel cylinder of one of the two brake systems via a hole 65 formed in the first housing middle part 4b and a primary output port 66 formed in the front part 4a of the housing. And the secondary chamber 55 is connected to the housing front 4
is connected to a wheel cylinder (not shown) of the other system of the two-brake system via a secondary output port 67 drilled in a.

The brake fluid pressure generating device 1 of this embodiment comprises a power chamber pressure of the power chamber 31 of the hydraulic booster 2 and a primary chamber 52 and a secondary chamber 55 of the master cylinder 3.
Is used in a so-called semi-full power brake system in which the master cylinder pressure is supplied to the wheel cylinders of the two-brake system, so that the power chamber pressure and the master cylinder pressure need to be equal. For this purpose, it is conceivable that the effective pressure receiving area of the power piston 12 and each effective pressure receiving area of the primary piston 43 and the secondary piston 44 are simply made equal. However, since the accumulated pressure of the accumulator, which is a hydraulic pressure source, is constantly acting on the annular groove 29 on the outer peripheral surface of the power piston 12 through the input port 27, the sliding resistance of the power piston 12 reduces the primary piston 43 and the secondary piston 4.
Since each of the effective pressure receiving areas is simply equalized in this manner, the power chamber pressure becomes higher than the master cylinder pressure because the effective pressure receiving areas are simply equalized. Therefore, in the brake fluid pressure generating device 1 of this example, each effective pressure receiving area of the primary piston 43 and the secondary piston 44 is smaller than the effective pressure receiving area of the power piston 12, and the power chamber pressure and the master cylinder pressure are equal. Is to be.

In the brake hydraulic pressure generating device 1 of this embodiment, the hydraulic booster 2 and the master cylinder 3 are formed separately. In this case, the power piston 12 in the hydraulic booster 2 is used. The dedicated return spring is omitted. Then, in order to return the power piston 12 to the inoperative position, the primary return spring 54 of the primary piston 43 in the master cylinder 3 is used.
The secondary return spring 57 of the secondary piston 44 is also used. As described above, the return spring of the master cylinder 3 is also used for the return of the power piston 12, so that the power piston 1
No special return spring is required, and
Since a space for disposing the dedicated return spring is not required, the number of components is reduced, and the brake fluid pressure generating device 1 can be simplified and downsized.

Next, the operation of the thus constructed brake fluid pressure generating device 1 of this embodiment will be described. When the brake is not operated without the brake pedal being depressed, the input shaft 22 does not advance, and the control valve 40 is in the non-operating state shown in FIGS. 1 and 2 as described above. Therefore, the power room 3
Since pressure fluid from the accumulator is not supplied to 1,
The power piston 12 does not operate, and the hydraulic booster 2 does not output. The right end 25e of the reaction force piston 25 is separated from the step 22a of the input shaft 22, and the flange 23a of the cylindrical stopper member 23 is
a of the first flange portion 25a of the reaction force piston 25 is separated from the stopper portion 25c of the reaction force piston 25, and is at a position advanced from the stopper portion 25c.

Further, the master cylinder 3 does not operate, and as shown in FIG.
Is located behind the third cup seal 47, and the primary chamber 52 communicates with the master cylinder reservoir 61 via the radial hole 58 and the passage holes 59 and 60. Further, the radial hole 62 of the secondary piston 44 is located behind the fifth cup seal 51, and the secondary chamber 55 is provided with the radial hole 6.
2 and through the passage holes 63 and 64, it communicates with the reservoir 61 for the master cylinder. Therefore, no master cylinder pressure is generated in the primary chamber 52 and the secondary chamber 55.

When the brake operation is performed by depressing the brake pedal, the input shaft 22, the cylindrical stopper member 23 and the cylindrical member 21 advance, and the ball valve 18 is seated on the second valve seat 21a as described above. The control valve 40 is switched away from the first valve seat 15c. As a result, the power chamber 31 is shut off from the reservoir for the hydraulic pressure booster and communicates with the accumulator, so that the pressurized liquid from the accumulator is introduced into the power chamber 31. When the pressure liquid introduced into the power chamber 31 becomes a pressure that overcomes the sliding resistance of the power piston 12 and the spring force of the primary return spring 54, the power piston 12 advances by the pressure liquid, and the hydraulic pressure booster 2 operates. At the same time, the primary piston 43 advances and the radial hole 58 thereof passes through the third cup seal 47, and a master cylinder pressure is generated in the primary chamber 52. At the same time, the pressure liquid in the power chamber 31
2 to two wheel cylinders of one system. Further, due to the master cylinder pressure generated in the primary chamber 52, the secondary piston 44 advances, the radial hole 62 passes through the fifth cup seal 51, and the master cylinder pressure is also generated in the secondary chamber 55. The master cylinder pressure generated in the secondary chamber 55 is introduced from the secondary output port 67 to both wheel cylinders of the other system.

As described above, the power chamber pressure in the power chamber 31 and the master cylinder pressure in the primary chamber 52 and the secondary chamber 55 are the same, and the same hydraulic pressure is applied to each wheel cylinder. Supplied, the brake pressures of the two brake systems are equal. Further, the power room 31
The pressure fluid in the inside is also introduced into the chamber 42 through the axial passage hole 41, and the hydraulic pressure in the chamber 42 causes the valve element 19 to move the input shaft 22.
Is biased in a direction against the input of.

The reaction force piston 2 is driven by the hydraulic pressure in the power chamber 31.
5 is the power piston 1 against the spring force of the spring 26
2 and the input shaft 22 are displaced to the right.
In the early stage of operation when each wheel cylinder has a loss stroke and each of these wheel cylinders does not substantially generate a braking force, it does not reach the point where the rear end 25e of the reaction force piston 25 comes into contact with the step 22a of the input shaft 22. Absent. Thus, the right end 25 e of the reaction force piston 25 is
The input shaft 22 does not receive any force from the reaction force piston 25 because it does not contact the stepped portion 22a. Therefore, the input shaft 22 receives a force due to the hydraulic pressure in the power chamber 31 which is received by the cylindrical stopper member 23 at the tip and the relatively small effective pressure receiving surface of the cylindrical member 21. It is transmitted to the driver as a reaction force.

When the reaction force of the input shaft 22 becomes equal to the input of the input shaft 22, the ball valve 18 moves to the first valve seat 15c and the second valve seat 15c.
The power chamber 31 is seated on any of the valve seats 21a, and is shut off from both the accumulator and the reservoir for the hydraulic booster. When the input of the input shaft 22 further rises, the ball valve 18 again separates from the first valve seat 15c, and the power chamber 3
1 is further supplied with a pressurized fluid of an accumulator and a power chamber 3
The fluid pressure in 1 further increases. After that, the ball valve 18
By repeatedly seating and unseating on the valve seat 15c, the hydraulic pressure in the power chamber 31 continuously increases at a predetermined boosting ratio as the input of the input shaft 22 increases.

During the loss stroke of each wheel cylinder, the right end 25e of the reaction force piston 25 is not in contact with the step 22a of the input shaft 22, so that the input shaft 22 to which the hydraulic pressure in the power chamber 31 acts is effective. The pressure receiving area is small, and the boost ratio at this time is large. For this reason, the output of the hydraulic booster 2 rises very greatly with respect to the input of the input shaft 22 at a large boost ratio, and the hydraulic booster 2 performs a so-called jumping action.

When the hydraulic pressure in the power chamber 31 further rises and the power piston 12 further moves forward and the loss stroke of each wheel cylinder is eliminated, each wheel cylinder generates a braking force, and substantially, two brake systems are used. The brakes are activated. In this state, the raised power chamber 31
The right end 25e of the reaction force piston 25 abuts on the step 22a of the input shaft 22 due to the hydraulic pressure in the input shaft 22, and the reaction force piston 25 applies a force to the input shaft 22 by the urging force due to the hydraulic pressure in the power chamber 31.
It acts to oppose the input of 2. Therefore, the reaction force acting on the input shaft 22 increases, and the hydraulic booster 2
Output of the input shaft 22 rises smaller than the input of the input shaft 22 during the loss stroke, and the jumping action ends.

Thereafter, since the reaction force of the hydraulic booster 2 becomes large, the input of the input shaft 22 is boosted and output at an ordinary relatively small boost ratio, and the hydraulic pressure in the power chamber 31 is reduced. The hydraulic pressure corresponds to this boost ratio. The hydraulic fluid in the power chamber 31 is supplied to one of the wheel cylinders, and the master cylinder 3 generates the master cylinder pressure by the output of the hydraulic booster 2, and the master cylinder generated in the secondary chamber 55. The pressure is supplied to the wheel cylinders of the other system, and each wheel cylinder of each system generates a large braking force with respect to the input of the input shaft 22, and the brake is operated by this braking force.

When the brake pedal is released to release the brake operation, the input shaft 22, the cylindrical stopper member 23 and the cylindrical member 21 are all retracted to the right, and the second valve seat 21a of the control valve 40 as described above. Is switched away from the ball valve 18, and the power chamber 31 is
d, a gap between the ball valve 18 and the second valve seat 21a, an axial hole 21b of the cylindrical member 21, an axial passage hole 33 and a radial passage hole 34 of the input shaft 22, and an annular groove 35 of the plug 10.
And a power passage through a radial passage hole 36, an annular space 37 between the plug 10 and the housing 4, an axial passage hole 38 in the rear part 4d of the housing, and a discharge port 39 to communicate with the reservoir for the hydraulic booster. The pressure fluid in 31 is discharged to the reservoir for the hydraulic booster. At this time, the cylindrical stopper member 23
The input shaft 22 is largely retracted until the flange portion 23a of FIG. 2 abuts against the stopper portion 25c of the reaction force piston 25, so that the second valve seat 21a is largely separated from the ball valve 18,
The control valve 40 opens greatly. Therefore, the pressure fluid in the power chamber 31 is quickly discharged, and the fluid pressure in the power chamber 31 decreases.

When the hydraulic fluid in the power chamber 31 is discharged, the hydraulic fluid in one of the wheel cylinders is also quickly discharged through the power chamber 31 to the reservoir for the hydraulic booster, and the secondary chamber 55 and the secondary chamber 55 are discharged. Return spring 5
7, the primary piston 43, the secondary piston 44, and the power piston 12 are quickly retracted together. With the retraction of the primary piston 43 and the secondary piston 44, the radial holes 58 and 62 pass through the third cup seal 47 and the fifth cup seal 51, respectively, and again the third cup seal 47 and the fifth cup seal 51 are closed. Since it is located rearward, both the primary chamber 52 and the secondary chamber 55 communicate with the master cylinder reservoir 61 again. Therefore, the pressure fluid of the wheel cylinder of the other system is also quickly discharged to the master cylinder reservoir 61 through the secondary chamber 55. As a result, the brakes of both brake systems are quickly released.

When the hydraulic pressure in the power chamber 31 decreases to a predetermined pressure, the reaction force piston 25 advances relative to the power piston 12 and the input shaft 22 by the spring force of the spring 26, and the flange of the valve seat member 15 The right end 25e of the reaction force piston 25 is separated from the step portion 22a of the input shaft 33 while being in contact with the portion 15a.

Until the brake release is almost completed, the input shaft 2
2 further retracts, the flange portion 23a of the cylindrical stopper member 23 moves to the tip 10c of the cylindrical protrusion 10a of the plug 10.
, The input shaft 22, the cylindrical stopper member 23, and the cylindrical member 21 stop retreating.
Both the cylindrical stopper member 23 and the cylindrical member 21 are in the retreat limit. However, even if the retraction of the input shaft 22, the cylindrical stopper member 23, and the cylindrical member 21 is stopped, the power piston 12, the reaction force piston 25, the ball valve 18, and the valve seat member 15 all continue to retreat. For this reason,
The flange portion 23a of the cylindrical stopper member 23 is separated from the stopper portion 25c of the reaction force piston 25, and the ball valve 18 approaches the second valve seat 21a of the cylindrical member 21.

When the rear end of the power piston 12 comes into contact with the plug 10 shown in FIGS.
Is stopped, the power piston 12 is in the inoperative position, and accordingly the primary piston 43 and the secondary piston 44 of the master cylinder 3 are also stopped in the inoperative position, and the brake is quickly and completely released. Is done. In this state, the ball valve 18 is connected to the second valve seat 21.
a, and the gap between the ball valve 18 and the second valve seat 21a becomes extremely small, and the seat is on the verge of being seated. Therefore, next, the brake pedal is depressed and the input shaft 2
2 and the cylindrical member 21 advance, the second valve seat 2 immediately
1a comes into contact with the ball valve 18, and the ball valve 18 immediately seats on the second valve seat 21a and separates from the first valve seat 15c. That is, the loss stroke for performing the switching operation of the control valve 40 becomes extremely small, and the brake operates quickly.

In this way, the brake is quickly operated when the brake is operated, and the brake is quickly released when the brake is released, so that the brake fluid pressure generating device 1 becomes extremely responsive.

If a hydraulic pressure source such as a pump or an accumulator fails and the hydraulic fluid of the accumulator does not flow into the power chamber 31 during a brake operation, the brake pedal is depressed and the input piston 8 moves forward in the same manner as described above. The cylindrical member 21 contacts the ball valve 18 and presses the valve body 19 forward through the ball valve 18. Then, the stopper portion 23a of the cylindrical stopper member 23 contacts the flange portion 15a of the valve seat member 15. Therefore, the input shaft 22 directly pushes the primary piston 43 via the cylindrical stopper member 23, the valve seat member 15, the power piston 12, and the adjustment member 49, so that the primary piston 43 moves forward. As a result, the radial hole 58 advances forward from the third cup seal 47 in the same manner as described above to generate a master cylinder pressure in the primary chamber 52, and the secondary piston 44
Is moved forward, so that the radial hole 62 is formed in the fifth cup seal 51.
The cylinder moves further forward and a master cylinder pressure is generated in the secondary chamber 55. The master cylinder pressure in the primary chamber 52 and the secondary chamber 55 is supplied to each wheel cylinder of the two-brake system via the primary output port 66 and the secondary output port 67, respectively, and the brake of the two-brake system is operated. Thus, even when the pump fails, the brake operation of the two-brake system is reliably performed.

As described above, according to the brake hydraulic pressure generating device 1 of this embodiment, a part of the primary piston 43 of the master cylinder 3 is disposed in the housing rear portion 4d of the hydraulic booster 2 and the power is increased. Since the small-diameter portion 12b at the front of the piston 12 is loosely fitted in the hole 48 at the rear end of the primary piston 43, the total length of the integrated assembly of the hydraulic booster 2 and the master cylinder 3 can be effectively reduced. Can be shorter.

The small diameter portion 12b of the power piston 12
The primary piston 4 of the master cylinder 3 is adjusted by an adjustment member 49 interposed between the primary piston 43 and the primary piston 43.
Since the stroke from the inoperative position of the third and secondary pistons 44 to the passage of the radial hole 58 and the radial hole 62 through the third cup seal 47 and the fifth cup seal 51 respectively is adjusted to a predetermined position, Hole 5
8 and the loss stroke of the radial hole 62, that is, the variation of the loss stroke of the primary piston 43 and the secondary piston 44 is reduced.

In the above-described hydraulic pressure generating device, the brake hydraulic pressure generating device 1 supplies the power chamber pressure to one wheel cylinder and supplies the master cylinder pressure to the other wheel cylinder. However, the hydraulic pressure generating device of the present invention is used only for the operation of the power piston 12 without supplying the power room pressure to the wheel cylinder of one system, and The present invention can also be applied to a brake system in which the master cylinder pressure in the chamber 52 is supplied to one system of wheel cylinders and the master cylinder pressure in the secondary chamber 55 is supplied to the other system.

Further, the brake fluid pressure generator 1 of the above-described example is used.
In the embodiment, the jumping characteristic is provided by the reaction force piston 25. However, the reaction force piston 25 is not always necessary and can be omitted.

Further, the hydraulic pressure generating device of the present invention is not limited to the two-system hydraulic pressure system, and the single master cylinder is operated by the output of the hydraulic booster to generate the single master cylinder. The present invention can also be applied to a single hydraulic system using only the master cylinder pressure. Further, the hydraulic pressure generating device of the present invention can be applied to a hydraulic system other than the brake system.

[0061]

As is apparent from the above description, according to the hydraulic pressure generating device of the first aspect of the present invention, a part of the piston of the master cylinder is disposed in the housing for the hydraulic booster. Since the front end of the power piston is inserted into the hole provided at the rear end of the piston of the master cylinder, the total length of the integrated assembly of the hydraulic booster and the master cylinder can be effectively reduced. Can be shortened.

Further, the loss stroke until the master cylinder pressure of the piston of the master cylinder is generated is adjusted to a predetermined value by the adjusting member interposed between the power piston and the piston of the master cylinder. Variations in the loss stroke of the cylinder can be reliably reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a brake hydraulic pressure generator to which an example of an embodiment of a hydraulic pressure generator according to the present invention is applied.

FIG. 2 is a partially enlarged cross-sectional view of the brake fluid pressure generating device shown in FIG.

FIG. 3 is a detailed sectional view of the reaction force piston shown in FIGS. 1 and 2;

4 is a partially enlarged cross-sectional view of the brake fluid pressure generating device shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Brake hydraulic pressure generator, 2 ... Hydraulic booster, 3 ... Master cylinder, 4a ... Housing front part (housing for master cylinder), 4b ... Housing 1st intermediate part (housing for master cylinder), 4c ... Housing 2nd intermediate part (housing for master cylinder), 4d ... rear part of housing (housing for hydraulic booster), 12 ... power piston, 12a ... large diameter part, 12b ... small diameter part, 15 ... valve seat member, 15c ... 1 valve seat, 16: cylindrical fixing member, 18: ball valve, 19: valve body, 21: cylindrical member, 21a: second valve seat, 22: input shaft, 22a: step portion, 23: cylindrical stopper member , 25 ... reaction force piston, 27 ... input port, 31 ... power chamber, 32 ... passage hole, 39 ... discharge port, 40 ... control valve, 43
... Primary piston, 45 ... First cup seal, 46
... Second cup seal, 47 ... Third cup seal, 49 ...
Adjusting member, 50: fourth cup seal, 51: fifth cup seal, 52: primary chamber, 54: primary return spring, 55: secondary chamber, 57: secondary return spring, 58: radial hole, 61: master cylinder Reservoir, 62: Radial hole, 66: Primary output port, 67: Secondary output port

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[Procedure amendment]

[Submission date] January 5, 2000 (2000.1.5)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

FIG. 4

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Hiroyuki Yamaga 2-11-6 Shinmeicho, Higashimatsuyama-shi, Saitama F-term in the Matsuyama Plant of Automotive Equipment Co., Ltd. (Reference) 3D047 BB15 BB33 BB41 CC09 CC13 CC19 FF16 JJ01 3D048 BB27 BB53 BB59 CC09 GG03 GG05 GG18 GG33 HH54 HH55 QQ07

Claims (5)

[Claims] 1. A housing for a hydraulic booster, a power chamber provided in the housing for the hydraulic booster and supplied with a hydraulic pressure from a hydraulic pressure source, and a housing for the hydraulic booster. A power piston that is provided and outputs by operating with the hydraulic pressure of the power chamber, an input shaft that operates with an input applied during operation, and a hydraulic pressure that is controlled by the input shaft and is supplied to the power chamber from a hydraulic pressure source. A hydraulic booster having at least a control valve for controlling the supply and discharge of the power chamber and generating a power chamber pressure corresponding to the input of the input shaft in the power chamber; and a housing separate from the hydraulic booster housing. A master cylinder housing formed and integrally connected to a front portion of the hydraulic booster housing, a master cylinder piston provided in the master cylinder housing and operated by an output of the power piston And a master cylinder having at least a master cylinder hydraulic pressure chamber in which a master cylinder pressure is generated when the master cylinder piston is in operation and the master cylinder pressure disappears when the master cylinder piston is not in operation. A part is disposed in the hydraulic booster housing, and a front end of the power piston is loosely fitted in a hole formed in a rear end of the master cylinder piston. An adjusting member is provided between the power piston and the master cylinder piston to adjust a stroke from a non-operating position of the master cylinder piston to a start of generation of the master cylinder pressure to a predetermined value. Hydraulic pressure generator. 2. The hydraulic pressure generator according to claim 1, wherein said power chamber pressure is supplied to one system, and said master cylinder pressure is supplied to another system. 3. A housing for the hydraulic booster, a power chamber provided in the housing for the hydraulic booster and supplied with a hydraulic pressure from a hydraulic pressure source, and in the housing for the hydraulic booster. A power piston that is provided and outputs by operating with the hydraulic pressure of the power chamber; an input shaft that operates with an input applied during operation; A hydraulic booster having at least a control valve that controls the supply and discharge of the power chamber and generates a power chamber pressure in accordance with the input of the input shaft in the power chamber; and a housing separate from the hydraulic booster housing. A master cylinder housing formed and integrally connected to a front portion of the hydraulic booster housing, a master cylinder piston provided in the master cylinder housing and operated by an output of the power piston And at least a master cylinder pressure chamber in which a master cylinder pressure is generated when the master cylinder piston is operated and the master cylinder pressure is extinguished when the master cylinder piston is not operated, wherein the master cylinder piston includes a primary piston and a secondary piston. And the master cylinder hydraulic chamber comprises a primary chamber and a secondary chamber, and the primary piston operates by the output of the power piston to generate a master cylinder pressure in the primary chamber, and the secondary piston is A master cylinder which is operated by a master cylinder pressure generated in the primary chamber and generates a master cylinder pressure in the secondary chamber, wherein a part of the primary piston is disposed in the hydraulic booster housing. Arrangement And a front end of the power piston is loosely fitted in a hole formed at a rear end of the primary piston. Further, at least the primary piston is located between the power piston and the primary piston. A pressure adjusting device for adjusting a stroke from a non-operating position to a start value of the master cylinder pressure to a predetermined value. 4. The power chamber pressure and the master cylinder pressure of one of the primary chamber and the secondary chamber are supplied to one system, and the master cylinder pressure of the other of the primary chamber and the secondary chamber is other than the other. 4. The hydraulic pressure generating device according to claim 3, wherein the hydraulic pressure generating device is supplied to the system. 5. The adjusting member is fitted into a hole formed at the tip of the power piston and is prevented from falling out of the hole by an elastic member. Further, the adjusting member has various lengths. The hydraulic pressure generator according to any one of claims 1 to 4, wherein an adjusting member is provided.