JP2001354132A - Brake boosting master cylinder and brake system using this - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake characteristic for nearly equalizing vehicle deceleration and a pedal stroke to pedal actuating force regardless of operation and nonoperation of the other brake system. SOLUTION: A pressure control means 68 directly connects a pump 56 to both passages 66 and 67 when both a friction brake system and the other system are not operated, and respectively supplies delivery pressure of the pump 56 to the passages 66 and 67 so hat a hydraulic pressure difference between respective hydraulic pressures of the passages 66 and 67 becomes a hydraulic pressure difference corresponding to friction brake independently operating time at the friction brake independently operating time, and respectively supplies the delivery pressure of the pump 56 to the passages 66 and 67 so that the hydraulic pressure difference between the respective hydraulic pressures of the passages 66 and 67 becomes a hydraulic pressure difference corresponding to brake cooperatively operating time at the brake cooperatively operating time for operating both a friction brake and the other brake system. Brake force and stroke characteristics can be almost equalized at the other brake operating time and nonoperating time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake system using a master cylinder pressure which is used together with another brake system such as a regenerative brake system. Brake pressure boosted master cylinder pressure that is output and belongs to the technical field of brake booster master cylinder. In particular, when another brake system is operated, the master cylinder pressure is equivalent to the braking force by the operation of this other brake system. The present invention belongs to the technical field of a brake pressure-increasing master cylinder that corrects a pedal stroke amount and reduces a pedal stroke in order to reduce a braking force caused by the brake pedal. In the following description, the master cylinder is also referred to as MCY.

[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, the piston of the brake master cylinder is operated by the output of the brake hydraulic pressure booster, MCY generates MCY pressure, and the MCY pressure is introduced into the wheel cylinder as brake hydraulic pressure, so that the brake operates. It is supposed to.

[0004]

By the way, in the conventional brake system, various normal brake systems using MCY pressure which are used together with another brake system such as a regenerative brake system have been proposed.

In such a brake system, MCY
In addition to the braking force due to the pressure, the braking force due to another braking system is applied. In this case, when the braking force of the MCY is applied by the normal braking operation while the braking force is being generated by another braking system, the total braking force of the vehicle becomes too large. Therefore, in such a case, the braking force by the MCY pressure must be reduced by the amount of the braking force by the other braking system. Therefore, when the other brake system is operated, when the normal brake is operated with the same input as the input during the normal brake operation when the other brake system is not operated, the pedal stroke is smaller than the pedal stroke during the normal brake operation. There is a need to. Also,
When the normal brake is operated when the other brake system is operated, the pedal input needs to be smaller than when the normal brake is operated when the other brake system is not operated.

As described above, in a braking system in which a braking force is applied by another braking system in addition to the braking force by the MCY pressure, correction of the MCY pressure and the pedal stroke in the braking system by the MCY pressure is required. In this case, especially when the stroke characteristics are changed, the system configuration becomes complicated in the conventional brake system using the MCY pressure, and a brake feeling becomes a problem in artificially creating such stroke characteristics.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has as its object to reduce the vehicle deceleration relative to the pedal depression force (regardless of the operation or non-operation of another brake system such as a regenerative brake system). An object of the present invention is to provide a brake pressure-increasing master cylinder capable of obtaining brake characteristics that make brake force) and pedal stroke substantially the same. Another object of the present invention is to provide a brake pressure increasing master cylinder having a stroke characteristic capable of shortening a pedal stroke irrespective of operation or non-operation of another brake system such as a regenerative brake system. Still another object of the present invention is to provide a brake pressure-increasing master cylinder capable of improving brake feeling even when stroke characteristics are corrected.

[0008]

According to an aspect of the present invention, there is provided an input shaft which is stroked by an input applied at the time of operation, and which is operated and controlled by the input shaft in accordance with the input. A control valve for generating a controlled hydraulic pressure;
A booster chamber to which a hydraulic pressure controlled by the control valve is supplied, and at least a master cylinder piston which operates with the hydraulic pressure supplied to the booster chamber to generate a master cylinder pressure; An input shaft stroke control means for controlling a stroke of the input shaft in accordance with a stroke of a cylinder piston or the master cylinder pressure is provided.

The invention according to claim 2 further includes a reaction chamber in which a hydraulic pressure controlled by the control valve and acting on the input shaft as a reaction force is supplied, wherein the input shaft stroke control means includes: The stroke control sleeve is provided with a stroke control sleeve that is interlocked with the control valve.The stroke control sleeve acts on one end of the booster chamber in a direction in which the control valve generates the hydraulic pressure, and on the other end. The hydraulic pressure of the reaction force chamber is acted on in a direction in which the control valve does not generate a hydraulic pressure, and further,
The urging force of the first urging means is applied in a direction in which the control valve does not generate hydraulic pressure, and the urging force of the second urging means is applied in a direction in which the control valve generates hydraulic pressure. It is characterized by becoming.

Further, the invention of claim 3 provides a brake booster master cylinder according to claim 2, a brake pedal for operating the brake booster master cylinder, a pump connected to the brake booster master cylinder, A brake system including at least a wheel cylinder that is supplied with a master cylinder pressure of a brake booster master cylinder and performs a brake operation, wherein a pressure control unit is provided between the pump and the brake booster master cylinder, A control device for controlling the pressure control means based on a signal from another brake system is provided.

Further, the invention according to claim 4 is characterized in that the control device is arranged such that when the other brake system is inactive, the hydraulic pressure of the boosting chamber is higher than the hydraulic pressure of the reaction chamber.
Further, the pressure control means is controlled so that the hydraulic pressures of the two chambers become the same when the other brake system is operated.

Further, the invention according to claim 5 is characterized in that the control device controls the hydraulic pressure of the booster chamber and the hydraulic pressure of the reaction chamber to be the same when the other brake system is inactive. ,
Further, when the other brake system is operated, the pressure control means is controlled such that the hydraulic pressure of the reaction chamber becomes higher than the hydraulic pressure of the boost chamber. Further, the invention according to claim 6 is characterized in that the other brake system is a regenerative brake system.

[0013]

In the brake pressure increasing master cylinder according to the first aspect of the present invention, the stroke of the input shaft is controlled by the input shaft stroke control means in accordance with the stroke of the master cylinder piston or the master cylinder pressure. . This makes it possible to control the stroke of the input shaft to be reduced according to the stroke of the master cylinder piston or the master cylinder pressure.

According to the second aspect of the present invention, the stroke control sleeve for controlling the control valve is controlled by the pressure difference between the boosting chamber and the reaction chamber, thereby controlling the control valve. Therefore, by controlling the input applied to the input shaft and the reaction force of the input shaft due to the pressure of the reaction force chamber to be balanced, the input of the input shaft is not affected even if the pressure of the booster chamber changes. As a result, the input feeling is improved. In particular, since the stroke of the input shaft is controlled by the stroke control sleeve, a better feeling can be obtained.

On the other hand, in the brake system according to the third aspect, the pressure difference between the booster chamber and the reaction chamber is controlled by the pressure control means when the other brake system is not operating and when the other brake system is operating. The control can be performed such that the brake force due to the pressure is large when the other brake system is not operated, and is reduced when the other brake system is operated, by the brake force due to the operation of the other brake system.

In addition, even if the braking force due to the master cylinder pressure changes, the stroke of the input shaft is controlled by the input shaft stroke control means, so that the input when the other brake system is not operating and when the other brake system is operating is controlled. It is possible to control the stroke of the shaft so as to be substantially the same with little change.

Further, according to the present invention, when the other brake system is not operated by the pressure control means, the pressure in the booster chamber becomes larger than the pressure in the reaction force chamber, and the other brake system operates. When the system is in operation, the pressure difference between the two chambers is controlled so that the pressures in the two chambers are the same.

Further, according to the fifth aspect of the present invention, the pressure control means ensures that the pressures in both chambers are the same when the other brake system is inactive, and doubles when the other brake system is in operation. The pressure difference is controlled such that the pressure in the force chamber is greater than the pressure in the reaction chamber.

Further, in the invention of claim 6, a regenerative braking system is applied as another brake system. When the regenerative braking system is not operated, the braking force due to the master cylinder pressure is controlled to be large, and when the regenerative braking system is operated, the braking force is controlled to be reduced by the amount of the regenerative braking force due to the operation of the regenerative braking system. Moreover, even if the braking force due to the master cylinder pressure changes in this way, the input shaft stroke is controlled by the input shaft stroke control means, so that the stroke of the input shaft when the regenerative braking system is not operating and when the regenerative braking system is operating is reduced. It is controlled to be substantially the same with little change.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an example of an embodiment of a brake pressure-increasing master cylinder according to the present invention and a basic configuration of a brake system using the same. In the following description, “front” refers to the left of the figure in any of the figures, and “rear” refers to the right of the figure.

As shown in FIG. 1, the brake system in this basic configuration is a cooperative brake system employing a friction brake system and another brake system such as a regenerative brake system. The brake pressure increasing master cylinder 1 used in the friction braking system has an open center type control valve. The brake pressure-increasing master cylinder 1 includes a pressure-intensifying control unit 2 that generates a fluid pressure adjusted in accordance with an operating force of a brake operating member such as a pedal depression force of a brake pedal (not shown), and a pressure-intensifying control unit 2 that controls the pressure. And a master cylinder pressure generating section 3 for generating an MCY pressure increased by the increased hydraulic pressure.

The brake pressure-increasing master cylinder 1 has a housing 4. The housing 4 is formed with a first hole 5 opened at the right end and continuously with the left end of the first hole 5. A second hole 6 having a smaller diameter and a third hole formed continuously with the left end of the second hole 6 and having a diameter smaller than the diameter of the second hole 6.
The third hole 7 is formed continuously with the left end of the third hole 7.
The front end of a fourth hole 8 having a diameter smaller than the diameter of the hole 7 and a fifth hole 9 formed continuously with the left end of the fourth hole 8 and having a diameter smaller than the diameter of the fourth hole 8 is closed. It has a stepped hole.

A first cylindrical member 10 is fitted in the second to fourth holes 6 to 8 in the stepped holes. The first cylindrical member 10 is fitted in the fourth hole 8 in a liquid-tight manner and the third
And a large-diameter portion 10b fitted in the third hole 7 in a liquid-tight manner and extending into the second hole 6. An annular disk-shaped center plate 11 is fitted in the second hole 6 in a liquid-tight manner. Further, a bottomed second cylindrical member 12 is fitted in the first hole 5 in a liquid-tight manner. The second cylindrical member 12 has a small-diameter portion 12a having an outer diameter smaller than the inner diameter of the first hole 5 at a front end thereof, and a female screw portion 4a of the housing 4 at a rear end thereof.
Has a male screw portion 12b screwed into the screw hole. Then, the male screw portion 12b is screwed into the female screw portion 4a so that the front end of the first cylindrical member 10 abuts on the step 4b of the housing 4 at the boundary between the fourth hole 8 and the fifth hole 9. First cylindrical member 10, center plate 11, and second cylindrical member 1
2 are fixed so that they cannot move in the axial direction.

A cylindrical primary piston 13 is accommodated in the first cylindrical member 10. The primary piston 13 includes a front small-diameter portion 13a and a rear large-diameter portion 13b. The small-diameter portion 13a is provided in an inner hole of a bottomed cylindrical secondary piston 14 to be described later.
6, the large-diameter portion 13b is liquid-tightly and slidably fitted on the inner periphery of the first cylindrical member 10.

Further, a third cylindrical member 15 is provided in the fifth hole 9.
Are fitted and fixed in a liquid-tight manner.
The secondary piston 14 is accommodated in the inner hole, the fifth hole 9 and the inner hole of the first cylindrical member 10. The secondary piston 14 includes a front small diameter portion 14a, a central large diameter portion 14b, and a rear middle diameter portion 14c.
Is fitted in the inner hole of the third cylindrical member 15 in a liquid-tight and slidable manner by the second cup seal 17, and the large-diameter portion 14 b is liquid-tight and slidable in the inner periphery of the fifth hole 9. The small diameter portion 13a of the primary piston 13 is movably fitted in the inner hole of the middle diameter portion 14c as described above.
6 slidably fits in a liquid-tight manner.

The outer diameters of the large diameter portion 13b of the primary piston 13 and the large diameter portion 14b of the secondary piston 14 are set to be equal to each other, and the small diameter portions 13a, 13a at the front ends of the primary piston 13 and the secondary piston 14 are set. Each outer diameter of 14a is set equal to each other.

A first atmospheric pressure chamber 18 is formed in the inner hole of the secondary piston 14 between the front end of the primary piston 13 and the secondary piston 14, and the first atmospheric pressure chamber 18 Axial hole 1
9, a radial hole 20 of the primary piston 13, an annular space 21 between an inner periphery of the first cylindrical member 10 and an outer periphery of the primary piston 13, a radial hole 2 of the first cylindrical member 10.
2, an annular passage 23 between the inner periphery of the third hole 7 and the outer periphery of the first cylindrical member 10, and a radial hole 24 of the housing 4.
Through the reservoir 57 at all times. Also, the third
A second atmospheric pressure chamber 25 is formed in the inner hole of the cylindrical member 15 between the front end of the secondary piston 14 and the housing 4, and the second atmospheric pressure chamber 25 is formed in the third cylindrical member 1.
5 is always in communication with the reservoir 57 via the radial groove 26 at the front end and the radial hole 27 of the housing 4.

A first MCY pressure chamber 28 is formed inside the first cylindrical member 10 between the primary piston 13 and the rear end of the secondary piston 14.
The MCY pressure chamber 28 is always connected to a wheel cylinder (not shown) of a first brake system via a radial groove 29 formed at the front end of the first cylindrical member 10 and a passage hole 30 formed in the housing 4. ing. Further, a radial hole 31 that is always in communication with the first MCY pressure chamber 28 is formed in the middle diameter portion 14c of the secondary piston 14. When the first cup seal 16 is located behind the radial hole 31 as shown in the drawing, the radial hole 31 communicates with the first atmospheric pressure chamber 18, so that the first MCY pressure chamber 28 is Hole 3
When the first cup seal 16 is located forward of the radial hole 31, the radial hole 31 is shut off from the first atmospheric pressure chamber 18. Therefore, the first MCY pressure chamber 28 is cut off from the first atmospheric pressure chamber 18, that is, the reservoir 57.

On the other hand, a second MCY pressure chamber 32 is formed between the secondary piston 14 and the rear end of the third cylindrical member 15 inside the fifth hole 9 of the housing 4.
The CY pressure chamber 32 is provided with a passage hole 33 formed in the housing 4.
Through the second brake system (not shown). Further, a radial hole 34 is formed at the rear end of the third cylindrical member 15 so as to always communicate with the second MCY pressure chamber 32. When the second cup seal 17 is located behind the radial hole 34 as shown in the figure, the radial hole 34 communicates with the second atmospheric pressure chamber 25, so that the second MCY pressure chamber 32 It is connected to the second atmospheric pressure chamber 25, that is, the reservoir 57 through the hole 34,
When the cup seal 17 is located forward of the radial hole 34, the radial hole 34 is shut off from the second atmospheric pressure chamber 25, and the second MCY pressure chamber 32 is shut off from the second atmospheric pressure chamber 25, that is, the reservoir 57. It has become.

A boosting chamber 35 is formed in the inner hole of the first cylindrical member 10 between the rear end of the primary piston 13 and the front end of the center plate 11, and the boosting chamber 35 is formed in the first cylindrical member. Through a radial hole 36 formed in the cylindrical member 10 and always communicates with an annular passage 37 formed between the inner periphery of the second hole 6 of the housing 4 and the outer periphery of the first cylindrical member 10. I have. Further, a reaction chamber 38 is formed in the inner hole of the second cylindrical member 12 between the rear end of the center plate 11 and the second cylindrical member 12, and the reaction chamber 38 is formed in the second cylindrical member 12. The annular space 40 between the inner peripheral surface of the first hole 5 and the outer peripheral surface of the second cylindrical member 12 is always communicated via the radial hole 39 of the cylindrical member 12.

A first return spring 41 is contracted between the primary piston 13 and the secondary piston 14 in the first atmospheric pressure chamber 18, and the primary piston 13 is moved by the spring force of the first return spring 41. It is always biased backward. When the primary piston 13 is not operated, the rear end of the primary piston 13 is in contact with the center plate 11 as shown in the drawing, so that the primary piston 13 is in a retreat limit. At this time, the first cup seal 16 is located behind the radial hole 31, The first MCY pressure chamber 28 communicates with the reservoir 57 via the first atmospheric pressure chamber 18. A second return spring 42 is contracted between the secondary piston 14 and the third cylindrical member 15 in the second MCY pressure chamber 32,
The secondary piston 14 is constantly urged rearward by the spring force of the second return spring 42. When the secondary piston 14 is not in operation, the rear end of the secondary piston 14 is in contact with the front end of the first cylindrical member 10 as shown in the drawing, so that the secondary piston 14 is in a retreat limit. The second MCY pressure chamber 32 is located at the rear and communicates with the reservoir 57 via the second atmospheric pressure chamber 25.

An input shaft 43 extends through the second cylindrical member 12 in the housing 4 toward the front. The input shaft 43 includes a large-diameter portion 43a at the rear end, a medium-diameter portion 43b extending forward from the large-diameter portion 43a, and a medium-diameter portion 4b.
It comprises a small-diameter portion 43c extending further forward from 3b, and an extension 43d integrally connected to the small-diameter portion 43c. The large diameter portion 43a penetrates the rear end of the second cylindrical member 12 in a liquid-tight and slidable manner, and a brake pedal (not shown) is connected to the rear end of the large diameter portion 43a. The extension 43d is a small diameter portion 43d having the same diameter as the small diameter portion 43c.
_1, the greater than that of the small diameter portion 43d ₁ together consists diameter of the large-diameter portion 43d ₂ Prefecture, the large diameter portion 43d ₂ are slidably through which and liquid-tightly to the primary piston 13.

Further, a stroke control sleeve 44 made of a stepped cylindrical member is provided through the center plate 11, and the stroke control sleeve 44 is provided on a small diameter portion 43 c of the input shaft 43. A small diameter portion 44a loosely fitted with a gap, a large diameter portion 44b extending forward from the small diameter portion 44a, and a cylindrical valve sleeve 46 integrally connected to a rear end of the small diameter portion 44a. . The small diameter portion 44a penetrates the center plate 11 in a liquid-tight and slidable manner, and the large diameter portion 44b
d is slidably fitted in the large diameter portion 43d ₂ of. The large-diameter portion 44b also enters the primary piston 13 so that the hydraulic pressure in the booster chamber 35 acts rearward, that is, in a direction to close a control valve 52 described later. A first stroke control spring 45 is provided between the front end flange portion 44b ₁ of the large diameter portion 44b and the power piston 13.
(Corresponding to the first urging means of the present invention) is contracted,
The spring force of the stroke control spring 45 acts in a direction to open the control valve 52. The valve sleeve 46 is slidably fitted to the middle diameter portion 43b of the input shaft 43. The hydraulic pressure in the reaction force chamber 38 acts on the stroke control sleeve 44 in the forward direction, that is, in the direction to open the control valve 52. It is supposed to.

Further, at the rear end of the valve sleeve 46,
A spring retainer 47 is slidably fitted and a stopper ring 48 is attached. Between the center plate 11 and the spring retainer 47, a second stroke control spring 49 (the second stroke control spring
(Corresponding to an urging means) is contracted, and the spring force of the second stroke control spring 49 acts in a direction to close the control valve 52. The rear end of the spring retainer 47 is always in contact with the stopper ring 48 by the spring force of the second stroke control spring 49. Further, the first and second stroke control springs 45, 49
When the primary piston 13 makes a forward stroke, the stroke control sleeve 44
The set load and the spring constant are set so as to move relative to 3. That is, when the primary piston 13 is in the forward stroke, the stroke of the stroke control sleeve 44 with respect to the housing 4 is smaller than the stroke of the primary piston 13 with respect to the housing 4. Further, the stroke control sleeve 44 makes a relative stroke forward with respect to the housing 4 and a relative stroke backward with respect to the input shaft 43 when activated. Further, the set load of the first stroke control spring 45 is set to be larger than the set load of the second stroke control spring 49, so that the front end of the stroke control sleeve 44 contacts the primary piston 13 when not in operation. Has become.

The valve sleeve 46 has a radial hole 50 formed therein, and the radial hole 50 and the input shaft 43 are formed.
The step portion 51 between the middle diameter portion 43b and the small diameter portion 43c constitutes a control valve 52 configured as a throttle valve. The control valve 52 is fully opened when not in operation and does not generate any fluid pressure by not squeezing the brake fluid flowing therethrough. It is an open center type control valve that generates pressure.

An annular disk-shaped retainer 53 is slidably fitted to the middle diameter portion 43b of the input shaft 43. The disc-shaped retainer 53 can contact a step 54 between the large-diameter portion 43a and the middle-diameter portion 43b of the input shaft 43. A return spring 55 is contracted between the center plate 11 and the retainer 53, and the retainer 53 is constantly urged rearward by the spring force of the return spring 55. When the retainer 53 contacts the rear end of the second cylindrical member 12, the retraction limit is defined. When the brake pressure increasing master cylinder 2 is not operated, the retainer 53 contacts the rear end of the second cylindrical member 12 and the step 54 of the input shaft 43 is
To come into contact with.

Further, the passage 66 is connected to the passage 37, and the passage 67 is connected to the annular space 40.
The pressure control means 68 is connected to these passages 66 and 67, and the discharge side of the pump 56 is connected to the pressure control means 68. The pressure control means 6
8 and pump 56 are controllers 6
9 is electrically connected, and further, a controller 70 of another brake system is electrically connected to the controller 69.

The controller 69 controls the pressure control means 68 and the pump 56 based on the information of the deactivation and operation of the other brake system from the controller 70 of the other brake system and the deactivation and operation of the friction brake system. Has become. Thus, when the friction brake system and the other brake system are both inoperative, the pressure control means 68 directly connects the pump 56 to both the passages 66 and 67, and also operates the friction brake system and the other brake system. When the friction brake is not operated (hereinafter also referred to as the friction brake alone operation), the discharge pressure of the pump 56 is supplied to the passages 66 and 67 so that the hydraulic pressure difference between the respective hydraulic pressures of the passages 66 and 67 becomes the hydraulic pressure difference corresponding to the friction brake alone operation. Further, when the friction brake operation is performed and another brake system is operated (hereinafter, also referred to as brake cooperative operation), the hydraulic pressure difference between the hydraulic pressures in the passages 66 and 67 becomes a hydraulic pressure difference corresponding to the brake cooperative operation. Passages 66, 6
7 is supplied with the discharge pressure of the pump 56.

The operation balance formula of the stroke control sleeve 44 is as follows. Pressure receiving area of stroke control sleeve 44 Pressure receiving area on boosting chamber 35 side: A ₁ = A ₁₁ −A ₁₂ Pressure receiving area on reaction force chamber 38 side: A ₂ = A ₁₁ −A ₁₀ A ₁₀ : End of reaction force chamber 38 side part of the cross-sectional area of the inner hole of the valve sleeve 46 (input shaft cross-sectional area of diameter 43b in the 43) a _11: cross-sectional area of the outer peripheral shape of the small diameter portion 44a a _12: large diameter portion of the booster chamber 35 side end portion Cross-sectional area of the inner hole 44b (cross-sectional area of the outer peripheral shape of the extension 43d of the input shaft 43)
(A ₁₁ > A ₁₀ ; A ₁₁ > A ₁₂ ) First stroke control spring 45 Set load: S ₁ , spring constant: K ₁ Second stroke control spring 49 Set load: S ₂ , spring constant: K ₂ (S ₁ > stroke S ₂₎ the primary piston 13: S _t primary piston 13 of the stroke control sleeve 44
Stroke: L The urging force when the first stroke control spring 45 operates:
S ₁ + K ₁ · L Biasing force when the second stroke control spring 49 operates:
_{S 2 + K 2 · (S} t -L) boost chamber 35 during operation hydraulic pressure: fluid pressure in the reaction force chamber 38 when P ₁ operation: sliding against the sliding resistance input shaft 43 of the P ₂ stroke control sleeve 44 Dynamic resistance: f ₁ (direction: front) Sliding resistance to housing 4: f ₂ (direction: rear)

[0040] From the above, operation balance equation of the stroke control sleeve _{44, P 1 · A 1 + [} S 2 + K 2 · (S t -L)] + f 2 = P 2 · A 2
+ (S ₁ + K ₁ · L) + f ₁ Therefore, the relative stroke L of the stroke control sleeve 44 with respect to the primary piston 13 is L = (P ₁ · A ₁ -P ₂ · A ₂ + S ₂ -S ₁ + K ₂ · S _t + f ₂ -f ₁₎ / become _{(K 1 + K 2) (} 1).

The input shaft 43 controls the hydraulic pressure in the reaction force chamber 38 by the input shaft 4.
3, the throttle of the control valve 42 is maintained in a state commensurate with the input, so that the stroke of the input shaft 43 is shortened by the relative stroke L given by Expression 1, Accordingly, the pedal stroke is also reduced. Therefore, the stroke control sleeve 44
A stroke simulator mechanism (corresponding to the input shaft stroke control means of the present invention) for shortening the pedal stroke for a predetermined stroke of the primary piston 13 or a predetermined MCY pressure is configured. That is, the stroke simulator mechanism allows the stroke of the input shaft 43 to be shortened based on the stroke of the primary piston 13 or the MCY pressure. Now
If A ₁ = A ₂ = A is set, Equation 1 is expressed as L = (P ₁ −P ₂ ) · A + S ₂ −S ₁ + K ₂ · _St + f ₂ −f ₁ / (K ₁ + K ₂ ) (2) Become.

Next, the operation of the brake pressure-increasing master cylinder 1 and the brake system of the example configured as described above will be described. When the brake booster master cylinder 1 is not operated when the brake pedal is not depressed, the primary piston 13, the secondary piston 14, the input shaft 43,
Stroke control spring 44 and valve sleeve 4
6 is the retreat limit in the figure.

In the non-operating state shown in the drawing, the opening amount of the control valve 52 is maximum (full open). At this time, the reaction force chamber 38 has a radial hole 50, the control valve 52 having the maximum opening,
Cylindrical axial passage 61 between the inner peripheral surface of the small diameter portion 44a of the outer peripheral surface and the stroke control sleeve 44 of the small diameter portion 43c of the input shaft 43, the outer peripheral surface and the stroke control sleeve of the small diameter portion 43d ₁ of the extension portion 43d An annular space 62 between the large-diameter portion 44b and the inner peripheral surface of the large-diameter portion 44;
And via the axial hole 64 of the extension 43d to the axial hole 19 of the primary piston 13 and therefore
At this time, the reaction force chamber 38 is connected to the reservoir 57.

The boosting chamber 3 is controlled by the pressure control means 68.
Since the pressure chamber 5 and the reaction chamber are both connected to the discharge side of the pump 56, the boost chamber 35 is connected to the reaction chamber 38, and thus the boost chamber 35 is also connected to the reservoir 57. Further, the pump 56 is driven when the engine is started.

Accordingly, the brake fluid in the reservoir 57 is discharged from the pump 56, and the discharged brake fluid passes through the passage 67 connected to the pump 56 discharge side.
8 and further flows through the fully open control valve 52 and thereafter returns to the reservoir 57 through the aforementioned path.
At this time, since the control valve 52 is fully opened, the brake fluid flowing through the control valve 52 is not restricted at all, and the reaction chamber 3
No hydraulic pressure is generated at 8. Therefore, the reaction chamber 38 is at atmospheric pressure, and the boost chamber 35 connected to the reaction chamber 38 is also at atmospheric pressure.

The brakes of other brake systems (hereinafter referred to as brakes)
When the brake pedal is depressed and the normal brake operation is performed by the friction brake alone in a non-operating state of other brakes), the input shaft 43 makes a forward stroke. Then, since the opening amount of the control valve 52 becomes small, the control valve 52
The brake fluid flowing from the pump 56 is throttled, and a hydraulic pressure is generated in the reaction force chamber 38. Due to the generation of the hydraulic pressure in the reaction chamber 38, the hydraulic pressure is also generated in the booster chamber 35. At this time, the hydraulic pressure in the booster chamber 35 and the hydraulic pressure in the reaction chamber 38 correspond to the hydraulic pressure difference between the hydraulic pressure in the reaction chamber 38 and the hydraulic pressure in the booster chamber 35 by the pressure control means 68, respectively, corresponding to the friction brake alone operation. It is controlled so as to be a hydraulic pressure difference.

The hydraulic pressure in the boost chamber 35 causes the primary piston 13 to move forward, and the first cup seal 16 attached to the front end of the primary piston 13 has a radial hole 31.
And moves forward from the radial hole 31. Then, the first MCY pressure chamber 28 is cut off from the first atmospheric pressure chamber 18, and the primary piston 13 further advances, thereby causing the first MCY pressure chamber 28 to move forward.
MCY pressure is generated in the MCY pressure chamber 28.

Further, the secondary piston 14 moves forward by the MCY pressure in the first MCY pressure chamber 28, and the second cup seal 17 assembled at the front end of the secondary piston 14 passes through the radial hole 34 to It moves forward from the hole 34. Then, the second MCY pressure chamber 32 is shut off from the second atmospheric pressure chamber 25, and the secondary piston 14 further advances, so that MCY pressure is generated in the second MCY pressure chamber 32.

The respective MCY pressures of the first and second MCY pressure chambers 28, 32 are supplied to the respective wheel cylinders of the two brake systems via the passage holes 30, 33, respectively, and the wheel cylinders are operated to operate the MCY. The friction brake by pressure operates, that is, the normal brake operates. In this case, the outer diameters of the large-diameter portions at the axial center of the primary piston 13 and the secondary piston 14 are equal to each other, and the outer diameters of the front-end small-diameter portions of the primary piston 13 and the secondary piston 14 are set equal to each other. , First and second MCY pressure chambers 28,3
The two MCY pressures are equal to each other, and therefore the respective braking forces of the two brake systems are also equal.

On the other hand, since the hydraulic pressure in the reaction force chamber 38 acts on the step portion 54 of the input shaft 43, a reaction force is applied to the input shaft 43,
The control valve 52 controls the hydraulic pressure of the reaction force chamber 38 so that the reaction force balances the input of the input shaft 43. That is, the hydraulic pressure of the reaction force chamber 38 is controlled according to the input of the input shaft 43. At this time, the operation balance equation of the stroke control sleeve 44 is given by the following equation ( ₂ ): L = [K ₂ · _St + (P ₁ -P ₂ ) · AC] / (K ₁ + K ₂ ) (3) . Here, C = S ₂ −S ₁ + f ₂ −f ₁ > 0 is set. The value of C affects the start of stroke shortening. That is, if the value of C is large, the start of stroke shortening is delayed.

When another brake system is operated when the friction brake system is operated, or when the friction brake system is operated when the other brake system is operated,
As described above, the opening amount of the control valve 52 is reduced,
Hydraulic pressure is generated in the boost chamber 35 and the reaction chamber 38. At this time, the hydraulic pressures of the boosting chamber 35 and the reaction chamber 38 are respectively
The pressure control means 68 controls the hydraulic pressure difference between the reaction chamber 38 and the boost chamber 35 so that the hydraulic pressure difference corresponds to the brake cooperative operation. Due to the hydraulic pressure in the boost chamber 35, the brake boost MCY1 generates the MCY pressure in the same manner as described above. At this time, the MCY pressure is a hydraulic pressure based on another brake operation, and therefore, the brake cooperative operation is performed.

In the present invention, the boosting chamber 35
The following two cases are set for the control by the pressure control means 68 of the hydraulic pressure of the reaction force chamber 38 and the hydraulic pressure of the reaction force chamber 38. The control of the hydraulic pressures of the boosting chamber 35 and the reaction chamber 38 by the pressure control means 68 is not limited to this.

(I) It is set so that P ₁ > P ₂ at the time of the normal brake operation by the friction brake alone operation, and P ₁ at the time of the normal brake operation by the brake cooperative operation.
= P ₂ (in this case, the above-mentioned hydraulic pressure difference is 0). Since P ₁ > P ₂ when the friction brake is operated alone, the operation balance equation of the stroke control sleeve 44 at this time is given by Equation 3. When the friction brake is operated alone, the MCY pressure is large, so that the stroke of the primary piston 13 is also large. However, at this time, since P ₁ > P ₂ , the value of L in Equation 3 increases. For this reason, even if the stroke of the primary piston 13 is large, the stroke reduction amount L is large, so that the pedal stroke becomes small. The operation balance equation of the stroke control sleeve 44 at this time is given by Equation 2. Further, since P ₁ = P ₂ at the time of the brake cooperative operation, the operation balance formula of the stroke control sleeve 44 at this time is:
From Equation 3, L = (K ₂ · _St− C) / (K ₁ + K ₂ ) (4)

At the time of the brake cooperative operation, the MCY pressure is small, and accordingly, the stroke of the primary piston 13 is also small. Therefore, since the set load S _t of the first stroke control spring 45 is reduced in Formula 4, the value of L is smaller than the time of non-operation of the other brake.
Therefore, even if the stroke reduction amount L is small, the stroke of the primary piston 13 is small, so that the pedal stroke is small. In this way, there is almost no difference in pedal stroke between when the friction brake is operated alone and when the regenerative cooperative brake is operated, and the stroke can be shortened.

(Ii) At the time of the normal brake operation by the sole operation of the friction brake, it is set so that P ₁ = P ₂ (in this case, the above-mentioned hydraulic pressure difference is 0), and at the time of the normal brake operation by the brake cooperative operation Are set so that P ₁ <P ₂ . Since P ₁ = P ₂ when the friction brake is operated alone, the operation balance equation of the stroke control sleeve 44 at this time is given by Equation 4. At the time of this friction brake alone operation, since the stroke S _t of the primary piston 13 is large, the value of L increases in Formula 5. Also,
Since P ₁ <P ₂ at the time of the brake cooperative operation, the operation balance equation of the stroke control sleeve 44 at this time is expressed by the following equation (3).
More _{L = [K 2 · S t} - (P 2 -P 1) · A-C] a _{/ (K 1 + K 2)} (5).

[0056] with a stroke S _t of the primary piston 13 is smaller than when the brake cooperative operation, P _2> P
_Since it is _1, it is further subtracted by (P ₂ −P ₁ ) · A in Equation 5, and the value of L becomes smaller when other brakes are not operated than when normal brake is operated. However, since the stroke S _t of the primary piston 13 is small, the pedal stroke is smaller. In this way, there is no difference in the pedal stroke between the friction brake alone operation and the brake cooperative operation, and the stroke can be shortened.

When the depression of the brake pedal is released, the pressure control means 68 is deactivated. Further, since the input shaft 43 is retracted, the opening amount of the control valve 52 is increased, the throttle of the brake fluid by the control valve 52 is reduced, and the reaction force chamber 38 is reduced.
And the hydraulic pressure in the booster chamber 35 also decreases. Then, the primary piston 13 is retracted by the spring force of the first return spring 41 and the MCY pressure of the first MCY pressure chamber 28. Then, the MCY of the first MCY pressure chamber 28
The pressure of the secondary piston 14 is reduced by the spring force of the second return spring 42 and the M of the second MCY pressure chamber 32.
The MCY pressure in the second MCY pressure chamber 32 decreases due to the CY pressure.

When the first cup seal 16 moves rearward from the radial hole 31 by retreating the primary piston 13, the first
When the MCY pressure chamber 28 communicates with the first atmospheric pressure chamber 18, and when the second cup seal 17 moves rearward from the radial hole 34 by retreating the secondary piston 14, the second MCY pressure chamber 32 is connected to the second atmospheric pressure chamber 25. The first and second MCs
Each MCY pressure in the Y pressure chambers 28 and 32 is discharged to the reservoir 57 together. Primary piston 13, secondary piston 14, stroke control sleeve 44, and input shaft 4
3 are both in the retracted position shown in the figure, the first and second
The MCY pressure chambers 28 and 32, the boost chamber 35, and the reaction chamber 38 all become atmospheric pressure, the brake pressure-increasing master cylinder 1 is deactivated, and the brake is released.

When the pump 56 fails, the front end of the extension 43d of the input shaft 43 comes into direct contact with the primary piston 13 by causing the input shaft 43 to largely advance, thereby causing the primary piston 13 to stroke. As described above, the primary piston 13 is directly operated by the input of the input shaft 43, and the MCY pressure is generated as described above, and the brake is operated.

As described above, according to the brake pressure-increasing master cylinder 1 and the brake system of this embodiment, the hydraulic pressure of the booster chamber 35 and the reaction force chamber By controlling the hydraulic pressures of the brakes 38 as described above, these hydraulic pressure differences are controlled as described above, so that the brake force of the brake operation by the MCY pressure can be made larger at the time of the normal brake operation by the friction brake alone operation than at the time of the brake cooperative operation, At the time of brake cooperative operation, the amount of braking force by other brake operation,
The braking force due to the MCY pressure, that is, the braking force of the friction brake can be reduced.

Even if the braking force due to the MCY pressure during the independent operation of the friction brake and the braking force due to the MCY pressure during the coordinated operation of the brake change as described above, both the pedal stroke during the independent operation of the friction brake and the coordinated operation of the brake are different. Can be reduced, and the pedal strokes can be made substantially the same when the friction brake is operated alone and when the regenerative cooperative brake is operated.

Further, since the hydraulic pressure in the reaction chamber 38 is controlled so as to be balanced with the pedal input, even if the hydraulic pressure in the boost chamber 35 is changed between when the friction brake is operated alone and when the brake cooperative operation is performed, Influence on pedal input can be prevented.

Therefore, it is possible to perform the normal brake so that the brake force becomes substantially the same as a whole with substantially the same pedal depression force and substantially the same pedal stroke, regardless of the operation or non-operation of the other brakes. it can.
Moreover, since the stroke of the primary piston 13 or the MCY pressure is used as a reference, the pedal stroke can be reduced compared to the conventional brake system without deteriorating the pedal feeling, and a good pedal feeling can be obtained.

When the pump 56 fails, the primary piston 13 is directly operated by the input shaft 43, so that the brake can be reliably operated by manual force even in the case of such a hydraulic pressure failure.

FIG. 2 is a sectional view similar to FIG. 1, showing a specific example of the brake system of the present invention. The same components as those in the above-described example are denoted by the same reference numerals, and detailed description thereof will be omitted. In a specific example of this brake system,
A regenerative braking system is employed as the other braking system described above. Further, the brake booster MCY1 is exactly the same as the brake booster MCY1 in the brake system having the basic configuration described above. Further, a passage 58 which is always connected to the discharge side of the pump 56 is provided as the above-described passage 66, and a passage 58 which is the above-described passage 67 is provided.
There is provided a passage 59 branching from. Further, a pressure control valve 60 is used as the above-described pressure control means 68. The pressure control valve 60 is provided in the passage 59. That is, the discharge side of the pump 56 is directly connected to the boosting chamber 35 via the passage 58, and the reaction chamber 38 is connected to the Tsuro 5
8, are connected via a passage 59 and a pressure control valve 60.

The pressure control valve 60 is switched between the communicating position set when not operating and the operating position so that the hydraulic pressure in the boosting chamber 35 becomes higher than the hydraulic pressure in the reaction chamber 38 by a predetermined pressure. , 38 and a hydraulic pressure control position for controlling the hydraulic pressure. At this time, the predetermined pressure, which is the difference between the hydraulic pressure of the booster chamber 35 and the hydraulic pressure of the reaction chamber 38 and the valve opening pressure, is variable. The pressure control valve 60 is set to a communication position when the brakes are cooperatively operated, and is set to a hydraulic pressure control position when the friction brakes are operated alone. Other configurations of the brake system of this specific example are the same as those of the above-described basic configuration.

Next, the operation of the thus-configured brake pressure-increasing master cylinder 1 of this embodiment will be described. When the friction brake is not operated, the brake booster MCY1 is not operated as described above, and the primary piston 13, the secondary piston 14, the input shaft 43, the stroke control spring 44, and the valve sleeve 46 are all retracted as shown. Is limited. Further, as shown, the pressure control valve 60 is set at the communication position.

When the brake booster MCY1 shown in the drawing is not operated, the opening amount of the control valve 52 is maximum (full open). control valve 52 are a cylindrical outer circumference of the axial passage 61, the small diameter portion 43d ₁ of the extension portion 43d between the inner peripheral surface of the small diameter portion 44a of the outer peripheral surface and the stroke control sleeve 44 of the small diameter portion 43c of the input shaft 43 Surface and stroke control sleeve 44
Is connected to the axial hole 19 of the primary piston 13 through the annular space 62 between the inner peripheral surface of the large diameter portion 44b, the radial hole 63 of the extension 43d and the axial hole 64 of the extension 43d, Therefore, at this time, the reaction force chamber 38 is connected to the reservoir 57. Further, the boosting chamber 35 includes the radial hole 36, the passage 37, the passage 58, the passage 59, and the pressure control valve 6.
0, connected to the reaction chamber 38 via the annular space 40 and the radial passage 39, so that the boost chamber 35 is also connected to the reservoir 57.

Therefore, the brake fluid in the reservoir 57 is discharged from the pump 56, and the discharged brake fluid is supplied to the reaction chamber 38 through the communicating position of the pressure control valve 60, and furthermore, the fully opened control valve 52 is opened. And flows back to the reservoir 57 through the above-mentioned path. At this time, since the control valve 52 is fully opened, the brake fluid flowing through the control valve 52 is not throttled at all, and no hydraulic pressure is generated in the reaction force chamber 38. Therefore, the reaction chamber 38 is at atmospheric pressure, and the boost chamber 35 is also at atmospheric pressure.

When the brake pedal is depressed and the normal brake operation is performed in a state where the regenerative brake is not operated, the input shaft 43 moves forward and the pressure control valve 60 is switched to the hydraulic control position. Then, the opening amount of the control valve 52 becomes small, so that the brake fluid from the pump 56 flowing through the control valve 52 is throttled, and the reaction force chamber 38
A hydraulic pressure is generated at Due to the generation of the hydraulic pressure in the reaction chamber 38, the hydraulic pressure is also generated in the booster chamber 35. At this time, the pressure control valve 60
Is set at the hydraulic pressure control position, the hydraulic pressure in the booster chamber 35 is controlled to be higher than the hydraulic pressure in the reaction chamber 38 by a predetermined pressure.

In the brake system of this example, P ₁ > P ₂ is set when the friction brake is operated alone, the MCY pressure is large, and P ₁ = P ₂ is set when the regenerative cooperative brake is operated. That is, the pressure control valve 60 controls the hydraulic pressures of the booster chamber 35 and the reaction force chamber 38 corresponding to (i) by the pressure control means 66 described above.

Therefore, when the friction brake is operated alone, M
The CY pressure is large, so that the stroke of the primary piston 13 is also large. Therefore, the value of L in Equation 3 increases. For this reason, even if the stroke of the primary piston 13 is large, the stroke reduction amount L is large, so that the pedal stroke becomes small.

When the regenerative cooperative brake is operated, the MCY pressure is small, and the stroke of the primary piston 13 is also small. Therefore, since the set load S _t of the first stroke control spring 45 is reduced in Formula 4, the value of L is smaller than the inoperative regenerative braking. Therefore, even if the stroke reduction amount L is small, the stroke of the primary piston 13 is small, so that the pedal stroke is small.

As described above, the input-MCY pressure characteristic of the input shaft 43 of the brake pressure-increasing master cylinder 1 of this example shows a relatively large MCY pressure when the friction brake is operated alone.
Since the pressure is generated, the characteristic becomes relatively steep as shown by a solid line in FIG. 3A, and a relatively small MCY pressure is generated when the regenerative cooperative brake is operated. The characteristics are relatively gentle.

On the other hand, in the input-pedal stroke characteristic of the input shaft 43 in the brake pressure-increasing master cylinder 1 of this example, the stroke characteristic of the primary piston 13 when the friction brake is operated alone is indicated by a chain line in FIG. The characteristic has a relatively steep gradient, and when the regenerative braking is operated, the characteristic has a relatively gentle gradient as shown by a dotted line in FIG. As described above, the stroke of the primary piston 13 is greatly different between when the regenerative brake is activated and when it is not activated, and corresponds to the operation state of the regenerative brake.
In addition, the stroke characteristics of the input shaft 43 when the friction brake operates alone are as shown by the solid line in FIG.
When the regenerative braking is operated, the characteristics are substantially the same as those when the friction brake is operated alone, as indicated by the two-dot chain line in FIG. As described above, the stroke of the input shaft 43 is substantially the same regardless of whether the friction brake is operated alone or the regenerative cooperative brake is operated. In FIG. 4B, the difference between the stroke of the primary piston 13 indicated by the dashed line when the friction brake is operated alone and the stroke of the input shaft 43 indicated by the solid line when the friction brake is operated alone is the primary piston of the stroke control sleeve 44. 13 relative to the stroke L.

As described above, according to the brake pressure-increasing master cylinder 1 of this embodiment, when the regenerative braking operation is performed, the hydraulic pressure in the booster chamber 35 is reduced by the pressure control valve 60 to reduce the braking force due to the regenerative braking operation. Accordingly, the braking force by the MCY pressure can be reduced, and when the regenerative brake is not operated, the hydraulic pressure in the booster chamber 35 is increased by the pressure control valve 60 so that the friction brake can be operated alone (that is, the brake operation by the MCY pressure). The braking force can be increased.

Even if the braking force due to the MCY pressure during the regenerative cooperative brake operation and the braking force due to the MCY pressure during the friction brake alone operation change as described above, both the friction brake alone and the regenerative cooperative brake actuate the pedal. The stroke can be reduced,
The pedal stroke can be made substantially the same when the friction brake alone is operated and when the regenerative cooperative brake is operated. Further, since the fluid pressure in the reaction force chamber 38 is controlled so as to be balanced with the pedal input, even if the fluid pressure in the boost chamber 35 is changed between when the friction brake is operated alone and when the regenerative cooperative brake is operated, the pedal input is not changed. Can be prevented.

Therefore, regardless of the operation or non-operation of the regenerative brake, the normal brake can be made to have substantially the same overall brake force with substantially the same pedal depression force and substantially the same pedal stroke. .
Moreover, since the stroke of the primary piston 13 or the MCY pressure is used as a reference, the pedal stroke can be reduced compared to the conventional brake system without deteriorating the pedal feeling, and a good pedal feeling can be obtained. Other operations and other effects of the brake system of this embodiment are the same as those of the brake system having the above-described basic configuration.

FIG. 4 is a sectional view similar to FIG. 1, showing another embodiment of the brake system of the present invention. The same components as those in the above-described example are denoted by the same reference numerals, and detailed description thereof will be omitted. In the example shown in FIG. 2 described above, a passage 58 that is always connected to the discharge side of the pump 56 is provided as the above-described passage 66, and a passage 58 that is the above-described passage 67 is provided.
In this example, as shown in FIG. 4, a passage 58 that is always connected to the discharge side of the pump 56 is provided, and as shown in FIG. A passage 59 branched from 58 is provided. Further, a pressure control valve 60 is provided in the passage 59. That is, in the brake pressure increasing master cylinder 1 of this example, the discharge side of the pump 56 is
8 and the pump 5
The discharge side of No. 6 is connected to the boost chamber 35 via a passage 58, a passage 59 and a pressure control valve 60.

In the example shown in FIG. 2 described above, the pressure control valve 60 is set to the communication position when the regenerative brake is operated, and is set to the hydraulic pressure control position when the regenerative brake is not operated. Conversely, the brake pressure-increasing master cylinder 1 is set to the hydraulic pressure control position when the regenerative brake is operated, and is set to the communication position when the regenerative brake is not operated.

In the brake system of this example, P ₁ = P ₂ is set when the friction brake is operated alone, the MCY pressure is large, and P ₂ > P ₁ is set when the regenerative cooperative brake is operated. That is, the pressure control valve 60 controls the hydraulic pressures of the boosting chamber 35 and the reaction chamber 38 corresponding to (ii) by the pressure control means 66 described above. The other configuration of this example is the same as the example shown in FIG.

In the thus configured brake pressure-increasing master cylinder 1 of this embodiment, the setting of the pressure control valve 60 is different between the case where the regenerative brake is operated and the case where the regenerative brake is not operated, as compared with the case shown in FIG. different. That is, when the friction brake is operated alone, the pressure control valve 60 is set to the communication position. At this time, the hydraulic pressure P ₁ of the booster chamber 35 and the hydraulic pressure P _{2 of the} reaction chamber 38 are equal to each other, and the stroke control sleeve 4
4 is the same as Expression 4 described above. When the regenerative braking is activated, the pressure control valve 60 is set to the hydraulic pressure control position. At this time, the fluid pressure P ₂ of the reaction force chamber 38 is larger than the fluid pressure P ₁ of the booster chamber 35, hydraulic balance equation of the stroke control sleeve 44 is a formula 5 above.

Therefore, when the friction brake is operated alone, the
Stroke S of primary piston 13_tIs large,
In Equation 5, the value of L increases. Also, regeneration coordination blur
When the brake is activated, the stroke S of the primary piston 13 is
_tIs small and P_Two> P ₁So, in equation 5
And further (P_Two−P₁) · A is subtracted, and the value of L is friction
It becomes smaller than when the brake is operated alone. But the primer
Stroke S of the re-piston 13_tIs small, so the pedal
The stroke becomes smaller. In this way, the friction break
Pedal strike between single operation and regenerative braking operation
There is no difference in the stroke and the stroke can be shortened. this
Other operations and other effects of the example are shown in FIG.
Is the same as

In each of the examples shown in FIGS. 2 and 4 described above, the case where the regenerative braking system is used in combination with the braking system using the MCY pressure is described, but the present invention is not limited to this. Instead, any other brake system such as an engine brake system and a retarder may be used in combination with the brake system using the MCY pressure.

[0085]

As apparent from the above description, according to the brake pressure increasing master cylinder of the first aspect of the present invention, the input shaft stroke is controlled by the input shaft stroke control means to the master cylinder piston stroke or the master cylinder pressure. It is controlled accordingly. This makes it possible to control the stroke of the input shaft to be reduced according to the stroke of the master cylinder piston or the master cylinder pressure.

According to the second aspect of the present invention, the control valve is controlled by controlling the stroke control sleeve for controlling the control valve based on the pressure difference between the boosting chamber and the reaction chamber. By controlling the input applied to the shaft and the reaction force of the input shaft due to the pressure of the reaction force chamber,
Even if the pressure in the booster chamber changes, the influence on the input of the input shaft can be prevented, and the input feeling can be improved. In particular,
Since the stroke of the input shaft can be made smaller than that of the conventional brake system, a better feeling can be obtained.

On the other hand, according to the third to sixth brake systems, the pressure difference between the booster chamber and the reaction chamber is controlled by the pressure control means when the other brake system is not operating and when it is operating. The control can be performed such that the braking force due to the master cylinder pressure is large when the other braking system is not operating, and is reduced when the other braking system is operating, by the amount of the braking force due to the operation of the other braking system.

In addition, even if the braking force due to the master cylinder pressure changes, the stroke of the input shaft is controlled by the input shaft stroke control means, so that the input when the other brake system is not operating and when the other brake system is operating. It is possible to control the stroke of the shaft so as to be substantially the same with little change. That is, the stroke characteristics with respect to the input or the vehicle deceleration can be made substantially equal.

Further, according to the invention of claim 6, since a regenerative braking system is employed as another brake system, the braking force due to the master cylinder pressure is large when the regenerative braking system is not operating, and the regenerative braking is performed. During operation of the system, control can be performed to reduce the regenerative braking force due to the operation of the regenerative brake system. Moreover, even if the braking force due to the master cylinder pressure changes in this way, the input shaft stroke is controlled by the input shaft stroke control means, so that the stroke of the input shaft when the regenerative braking system is not operating and when the regenerative braking system is operating is reduced. It can be controlled to be substantially the same with little change.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an embodiment of a brake pressure-increasing master cylinder according to the present invention and a basic configuration of a brake system using the same.

FIG. 2 is a sectional view similar to FIG. 1, showing a specific example of the brake system of the present invention.

3A and 3B show brake characteristics of the brake pressure increasing master cylinder shown in FIG. 2; FIG.
FIG. 4B is a diagram illustrating a Y pressure characteristic, and FIG. 4B is a diagram illustrating a stroke characteristic of the input shaft with respect to an input of the input shaft.

FIG. 4 is a sectional view similar to FIG. 1, showing another specific example of the brake system of the present invention.

[Explanation of symbols]

1 ... brake pressure increasing master cylinder, 2 ... pressure increasing control part, 3
.. Master cylinder pressure generator, 4 housing, 11 center plate, 13 primary piston, 14 secondary piston, 16 first cup seal, 17 second cup seal, 18 first atmospheric pressure chamber, 25 2nd atmospheric pressure chamber, 28 ... 1st MCY pressure chamber, 32 ... 2nd MCY pressure chamber,
35: boost chamber, 38: reaction chamber, 43: input shaft, 44: stroke control sleeve, 45: first stroke control spring, 46: valve sleeve, 49: second stroke control spring, 52: control valve, 56 ... pump, 57 ...
Reservoir, 58 passage, 59 passage, 60 pressure control valve, 66, 67 passage, 68 pressure control means, 69 controller, 70 controller of another brake system

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroyuki Oka 2-11-6 Shinmeicho, Higashimatsuyama-shi, Saitama Bosch Brake System Co., Ltd. (72) Inventor Hiroaki Niino 1-1-1 Showacho, Kariya-shi, Aichi Prefecture Address Denso Corporation (72) Inventor Kazuya Maki 1-1-1, Showa-cho, Kariya City, Aichi Prefecture Incorporated Company (72) Inventor Mamoru Sawada 1-1-1, Showa-cho, Kariya City, Aichi Prefecture Co., Ltd. F term in DENSO (reference) 3D046 BB03 CC02 DD02 EE01 HH00 HH02 HH16 LL06 LL11 LL14 LL17 LL37 3D048 BB25 BB26 BB27 CC10 DD02 FF23

Claims (6)

[Claims] An input shaft that strokes with an input applied during operation, a control valve that is operated and controlled by the input shaft to generate a hydraulic pressure that is controlled in accordance with the input, and a fluid that is controlled by the control valve. A booster chamber to which pressure is supplied, and a master cylinder piston that operates with the hydraulic pressure supplied to the booster chamber to generate a master cylinder pressure, further comprising: a stroke of the master cylinder piston or the master cylinder. A brake pressure increasing master cylinder comprising input shaft stroke control means for controlling a stroke of the input shaft according to a pressure. 2. The control apparatus according to claim 2, further comprising a reaction chamber controlled by said control valve and supplied with a hydraulic pressure acting as a reaction force on said input shaft, wherein said input shaft stroke control means includes a stroke interlocked with said control valve. The stroke control sleeve is provided with a hydraulic pressure in the boost chamber at one end in a direction in which the control valve generates the hydraulic pressure, and a hydraulic pressure in the reaction chamber at the other end. The control valve is acted on in a direction in which no hydraulic pressure is generated, and the urging force of the first urging means is acted on in a direction in which the control valve does not generate hydraulic pressure, and the urging force of the second urging means is 2. The brake pressure increasing master cylinder according to claim 1, wherein the control valve is operated in a direction in which the control valve generates a hydraulic pressure. 3. A brake booster master cylinder according to claim 2, a brake pedal for operating the brake booster master cylinder, a pump connected to the brake booster master cylinder, and a master of the brake booster master cylinder. A brake system including at least a wheel cylinder to which a cylinder pressure is supplied to perform a brake operation, wherein a pressure control unit is provided between the pump and the brake pressure increasing master cylinder, and a signal from another brake system is provided. A control device for controlling the pressure control means based on the control signal. 4. The control device according to claim 1, wherein the hydraulic pressure in the booster chamber is higher than the hydraulic pressure in the reaction chamber when the other brake system is inactive. 4. The brake system according to claim 3, wherein said pressure control means is controlled so that the hydraulic pressures of said two chambers become equal during operation. 5. The control device according to claim 1, wherein the hydraulic pressure of the booster chamber and the hydraulic pressure of the reaction chamber are the same when the other brake system is not operated, and the other brake is provided. 4. A brake system according to claim 3, wherein said pressure control means is controlled such that a hydraulic pressure of said reaction force chamber becomes higher than a hydraulic pressure of said booster chamber when the system operates. 6. The brake system according to claim 3, wherein the other brake system is a regenerative brake system.