JPH10196834A - Booster valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To activate the pressure boost function of a booster valve only upon necessity. SOLUTION: When a vacuum is normally produced in a booster valve 13, a pressure-boost inhibition piston 20 suffers the maximum differential pressure at both its surfaces 20a and 20b to maximize its pressing force to a valve plunger 14, in which condition the crossover point of the booster valve 13 is extremely raised. If the pressure Pm in a master cylinder 8 falls within the pressure range for service braking at the same time, the booster valve 13 effects no pressure boost. When a vacuum is insufficiently produced in the booster valve 13, on the other hand, the pressure-boost inhibition piston 20 suffers no differential pressure at both surfaces 20a and 20b to nullify its pressing force to the valve plunger 14, in which condition the crossover point of the booster valve 13 is relatively lowered. After any braking operation, the booster valve 13 in that state promptly effects a pressure boost. The pressure boost function of the booster valve 13 is thus activated upon necessity and inhibited otherwise.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a pressure increasing valve which performs a pressure increasing operation for increasing a hydraulic pressure generated by a hydraulic pressure generating device such as a master cylinder. The present invention belongs to the technical field of a pressure-intensifying valve that performs an operation and does not perform an operation of increasing pressure when pressure increase is unnecessary.

[0002]

2. Description of the Related Art Conventionally, for example, in an automobile, for example, a hydraulic brake system has generally been adopted in which hydraulic pressure generated in a master cylinder is introduced into a wheel cylinder to operate a brake. As an example of a conventional hydraulic brake system, for example, a hydraulic pressure booster as shown in FIG. 10 is used to boost the pedal effort and output the same, and the master cylinder is operated by this output to generate a large brake pressure. There is a pressure brake boost system. In the drawing, 1 is a hydraulic brake booster system, 2 is a brake pedal, 3 is a hydraulic booster, 4 is a pump, 5 is a motor M, 6 is an accumulator, 7 is a reservoir for a booster, and 8 is a tandem master. Cylinder (hereinafter also referred to as MCY), 9 is an MCY reservoir, 10 is a wheel cylinder (hereinafter also referred to as W / C)
It is.

In such a hydraulic brake booster system 1, when the motor 5 is driven to operate the pump 4, the hydraulic fluid in the booster reservoir 7 is supplied to the hydraulic booster 3 and the accumulator. 6 and a predetermined hydraulic pressure is stored in the accumulator 6. In this state,
When the brake pedal 2 is depressed, the control valve (not shown) of the hydraulic booster 3 is switched, and the hydraulic pressure of the accumulator 6 is introduced into the power chamber (not shown) of the hydraulic booster 3 according to the pedaling force. The power piston (not shown) boosts the pedal effort by the hydraulic pressure introduced into the power chamber and outputs the boosted power. The output of the hydraulic booster 3 is used to output MCY8.
Is operated, MCY8 generates MCY pressure Pm, and this MCY pressure Pm is used as the brake fluid pressure as W / C1
Supplied to zero and the brake is applied. At this time, the pedaling force is boosted by the hydraulic booster 3, so that the braking force is large.

As another example of a conventional hydraulic brake system, there is a negative pressure brake boosting system for obtaining a large brake pressure by boosting the pedal depression force by a negative pressure booster as shown in FIG. 11, for example. In the figure, reference numeral 11 denotes a negative pressure brake booster, and 12 denotes a negative pressure booster. Since the negative pressure booster 12 is very well known, its detailed structure is not shown, but for example, refer to JP-A-2-164656.

[0005] Such a negative pressure brake booster system 11
In (2), the negative pressure booster 12 includes a diaphragm piston (not shown) that partitions a constant pressure chamber into which a negative pressure is always introduced and a variable pressure chamber. When the brake pedal 2 is depressed, a control valve (not shown) of the negative pressure booster 12 is switched, and the atmosphere is introduced into the variable pressure chamber according to the pedal depression force. The atmospheric pressure introduced into the transformer chamber causes the diaphragm piston to boost the pedal effort and output. Similarly, the piston of the MCY 8 is operated by the output of the negative pressure booster 12, and the MCY pressure Pm generated by the MCY 8 becomes W /
It is supplied to C10 and the brake is applied. At this time, the pedaling force is boosted by the negative pressure booster 12, so that the braking force is large.

The brake booster system employs various power sources such as a positive pressure air pressure or an electromagnetic force in addition to a hydraulic pressure and a negative pressure as a power source for the above-described boosting. There is a brake boost system. In addition, there are various types of boosters in a brake booster system using the same power source.

[0007]

In the brake boosting system such as the hydraulic brake boosting system 1 and the negative pressure brake boosting system 11 described above,
Boosters such as the hydraulic booster 3 and the negative pressure booster 12 are relatively large and expensive. The output of such a booster is limited by its capacity.
In order to increase the output of the booster beyond the limit, it is necessary to increase the capacity of the booster. However, if the capacity of the booster is increased, the booster becomes larger.

Therefore, as shown in FIG. 12A, for example, the MCY pressure Pm generated by the pedal depression force is increased without using the hydraulic booster 3 or the negative pressure booster 12 as described above. A brake boosting system that increases the braking force is conceivable.

As shown in FIG. 12A, in this brake booster system, a pressure increasing valve 13 is provided in a brake passage connecting the MCY 8 and the W / C 10. The pressure increasing valve 13 includes a valve plunger 14 having a valve portion 14a, a valve seat 15 formed of a rubber sheet on which the valve portion 14a can be seated, and a valve plunger 14 in a direction in which the valve portion 14a is separated from the valve seat 15. Spring 19 that constantly urges
And In this case, when the valve portion 14a is seated on the valve seat 15, the effective pressure receiving area S1 on the MCY8 side of the valve plunger 14 is larger than the cross-sectional area S2 of the portion (small diameter portion 14b) of the valve plunger 14 where pressure is not received (S1> S).
2) It is set. As the pressure increasing valve 13, a proportioning valve (P valve) which has been widely used in the past can be used in reverse. However, the present invention is not limited to this, and any valve having the above-described configuration can be used. Such a structure may be used.

The motor 16 is operated by the MCY.
Pump 1 for supplying brake fluid 3 to W / C 10
7 bypasses the pressure-intensifying valve 13 and
3, and a pedal switch 18 for detecting depression of the brake pedal 2 is provided.

In this brake booster system, when the brake pedal 2 is depressed, the pedal switch 18
Detects this, the motor 16 is driven and the pressure increasing pump 17 is operated. As means for detecting a brake operation by depressing the brake pedal 2, there are various detecting means other than the pedal switch 18, such as a pressure spring or a pressure sensor for detecting the MCY pressure Pm, a stroke sensor for detecting the pedal stroke, and the like. .

When the brake pedal 2 is depressed, MC
Since the MCY pressure is generated at Y8, the valve plunger 14
Strokes immediately, and the valve portion 14a is seated on the valve seat 15. At this time, the MCY pressure P on the input side of the pressure increasing valve 13
The relationship between m and the W / C pressure Pw on the output side is

[0013]

(Equation 1)

## EQU1 ##

When the valve portion 14a is seated on the valve seat 15, W /
The C pressure Pw is increased by the discharge pressure of the pressure increasing pump 17. Then, when the W / C pressure Pw rises above the pressure Pw represented by Expression 1, the valve plunger 14 is pushed back, and the valve portion 14a is separated from the valve seat 15. As a result, the W / C pressure Pw escapes to the MCY 8 side and falls, and when the W / C pressure Pw returns to the pressure Pw of Equation 1, the valve plunger 14 again strokes rightward and the valve portion 14
a sits on the valve seat 15 and balances. Thus, W /
The C pressure Pw is increased by increasing the MCY pressure Pm so that the formula 1 is satisfied. When the spring force SPG of the spring 19 is set to be extremely small, the S pressure of the formula 1 is increased.
Since the term of PG becomes almost zero, the pressure increasing valve 13
The input / output characteristics as shown by the solid line in FIG.

As described above, according to the brake booster system shown in FIG. 12A, it is possible to increase the MCY pressure by the pedal depression force without using the hydraulic booster 3 or the negative pressure booster 12. It becomes possible.

Incidentally, in the pressure boosting valve 13 of such a brake booster system, the valve plunger 14
The spring force of the spring 19 that constantly biases the valve plunger 14 is set to be extremely weak so that when the MCY pressure is generated in the MCY 8, the valve plunger 14 immediately strokes.
The pressure increasing valve 13 increases the pressure of this input as soon as there is an input and outputs it.

However, in the brake booster system, the input / output characteristics of the pressure increasing valve 13 are as shown in FIG.
As shown in, output without increasing the pressure until the input becomes a predetermined size, when the input is more than a predetermined size,
In some cases, input / output characteristics having a break point (pressure increase start point) such that the input is increased in pressure and output is required. Therefore, by setting the spring force of the spring 19 to a size that does not cause the valve plunger 14 to stroke rightward until the MCY pressure Pm reaches a predetermined pressure, the pressure-intensifying valve 1
3 can have the input / output characteristics shown in FIG.

Incidentally, in the brake booster system, for example, two systems of brake systems such as a loaded state of the vehicle, an emergency brake operation, or a malfunction state of the booster function of the hydraulic booster 3 or the negative pressure booster 12 are used. Since various conditions such as the failure of one system at the time can occur, depending on various brake operating conditions required for the brake booster system, a case where the pressure increasing operation of the pressure increasing valve 13 is required and a case where the pressure increasing operation is required. And sometimes not. Similarly, there is a brake system without a booster in such a brake system, and even in such a brake system, it may be necessary to increase the pressure due to various conditions.

However, when a pressure increasing valve 13 having the input / output characteristics shown in FIG. 12C is provided in a brake system (including a system having a booster) under such a brake operating condition, the pressure increasing effect is obtained. Irrespective of the necessity or unnecessary, when the MCY pressure Pm rises past the break point, the pressure increasing valve 13 always performs the pressure increasing action.
For this reason, it is conceivable that it is not possible to flexibly and surely cope with the above-mentioned various brake operating conditions required for the brake system. It is desirable to be able to flexibly and reliably respond to various brake operating conditions.

The present invention has been made in view of such circumstances, and has as its object to be able to perform a pressure-increasing action when pressure-increasing is required and to perform pressure-increasing action when pressure-increasing is not necessary. The object is to provide a pressure intensifier valve that can be prevented from performing.

[0022]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is to derive an output port from which a hydraulic pressure from a hydraulic pressure generator is introduced, an output hydraulic pressure, and a pressure booster. An output port through which a pressure-increasing hydraulic pressure from a hydraulic pressure source is introduced, and when the hydraulic pressure of the input port is smaller than a predetermined pressure, the communication between the input port and the output port is performed so that the hydraulic pressure of the input port is increased. Is output from the output port as the output hydraulic pressure, and when the hydraulic pressure of the input port is equal to or higher than the predetermined pressure, the pressure between the input port and the output port is shut off, and the pressure-increasing fluid is supplied to the output port. A valve plunger that derives from the output port a hydraulic pressure obtained by increasing the hydraulic pressure of the input port by introducing pressure as the output hydraulic pressure, and a hydraulic pressure of the input port to the valve plunger when pressure increase is unnecessary. Apply pressure to oppose and prohibit pressure increase It is characterized by comprising a pressure increase inhibit control means to perform for increasing pressure action by releasing the action of the pressing force to the valve plunger when the pressure increase necessary.

According to a second aspect of the present invention, there is provided an input port to which the hydraulic pressure from the hydraulic pressure generator is introduced, and an output to derive the output hydraulic pressure and to introduce the pressure increasing hydraulic pressure from the pressure increasing hydraulic pressure source. Port, when the hydraulic pressure of the input port is smaller than a predetermined pressure, communicates between the input port and the output port, and derives the hydraulic pressure of the input port from the output port as the output hydraulic pressure, When the fluid pressure at the input port is equal to or higher than the predetermined pressure, the pressure between the input port and the output port is shut off, and the fluid pressure at the input port is increased by introducing the pressure increasing fluid pressure to the output port. A valve plunger that derives the pressurized hydraulic pressure from the output port as the output hydraulic pressure, and sets the valve seat to a position where the valve portion cannot be seated when pressure increase is unnecessary, thereby inhibiting the pressure increase effect and increasing the pressure. When the pressure is required, the valve seat is set to a position where the valve section can be seated, and the pressure is increased. It is characterized by comprising a pressure increase inhibit control means to perform.

Further, the invention of claim 3 is characterized in that the operation of the pressure increase inhibition control means is controlled by any one of negative pressure, positive pressure air pressure, liquid pressure and electromagnetic force. Further, the invention of claim 4 is characterized in that the pressing force by the pressure increase inhibition control means is controlled by a hydraulic pressure from the hydraulic pressure generating device.

Further, according to a fifth aspect of the present invention, there is provided an input port into which the hydraulic pressure from the hydraulic pressure generating device is introduced, and an output from which the output hydraulic pressure is derived and the pressure increasing hydraulic pressure from the pressure increasing hydraulic pressure source is introduced. Port, when the hydraulic pressure of the input port is smaller than a predetermined pressure, communicates between the input port and the output port, and derives the hydraulic pressure of the input port from the output port as the output hydraulic pressure, When the hydraulic pressure at the input port is equal to or higher than the predetermined pressure, the input port moves to shut off the connection between the input port and the output port, and the hydraulic pressure at the input port is introduced by introducing the pressure increasing hydraulic pressure to the output port. A valve plunger that derives the pressure-increased hydraulic pressure from the output port as the output hydraulic pressure, and enables the valve plunger to move to the extent that the hydraulic pressure of the input port can be increased when pressure increase is required. When the pressure increase is unnecessary, the valve plunger Both are characterized by comprising a valve plunger movement control means for movement preventing or movement limiting the extent of disabling the pressure increase of the hydraulic pressure of the input port.

According to a sixth aspect of the present invention, the valve plunger movement control means is arranged such that an end of the valve plunger opposite to the end on which the hydraulic pressure of the input port acts is disposed and the valve plunger is filled. And a control means for sealing the liquid chamber when pressure increase is not necessary and releasing the liquid seal of the liquid chamber when pressure increase is required to bring the liquid chamber to an atmospheric pressure state. .

According to a seventh aspect of the present invention, the valve plunger movement control means is provided to face the end of the valve plunger opposite to the end of the input port on which the hydraulic pressure acts. And a lock member having a lock portion and a lock release portion, and when the pressure increase is required, the lock release portion is opposed to the opposite end of the valve plunger to move the valve plunger for the pressure increase operation. Actuating the lock member so that the lock portion is opposed to the opposite end of the valve plunger when pressure increase is unnecessary, so as to prevent movement required for the pressure increase operation of the valve plunger. And control means for controlling the

Further, according to the present invention, an input port into which the hydraulic pressure from the hydraulic pressure generating device is introduced, and an output from which the output hydraulic pressure is derived and the pressure increasing hydraulic pressure from the pressure increasing hydraulic pressure source is introduced. Port, when the hydraulic pressure of the input port is smaller than a predetermined pressure, communicates between the input port and the output port, and derives the hydraulic pressure of the input port from the output port as the output hydraulic pressure, When the fluid pressure at the input port is equal to or higher than the predetermined pressure, the pressure between the input port and the output port is shut off, and the fluid pressure at the input port is increased by introducing the pressure increasing fluid pressure to the output port. A valve plunger that derives the pressurized hydraulic pressure from the output port as the output hydraulic pressure, and a bypass passage that connects the input port side and the output port side by bypassing a path in which the valve plunger performs a pressure increasing operation. And when the bypass passage is shut off when pressure increase is required Moni, is characterized by comprising a communication control unit a bypass passage for opening the bypass passage at increasing 圧不 required.

Further, the invention according to claim 9 is characterized in that the communication control means is constituted by a bypass valve having a valve piston which is controlled by the hydraulic pressure from the hydraulic pressure generator and controls opening and closing of the bypass passage. Features.

[0030]

In the pressure-intensifying valve according to the first aspect of the present invention, when the pressure-increasing is not required, the pressure-inhibiting control means applies a pressing force to the valve plunger so as to oppose the hydraulic pressure of the input port when pressure-increasing is unnecessary. Acted upon. As a result, the hydraulic pressure at the input port for starting the movement of the valve plunger becomes extremely large beyond the normal range, and the break point of the pressure increasing valve is set at an extremely high position. Therefore, when the hydraulic pressure at the input port is within the normal range, the pressure increasing action is prohibited, and the pressure increasing valve does not perform the pressure increasing action. When pressure increase is necessary,
The action of the pressing force from the pressure increase inhibition control means on the valve plunger is released. As a result, the hydraulic pressure at the input port for starting the movement of the valve plunger becomes relatively small in the normal region, and the break point of the pressure increasing valve is set at a relatively low position. Therefore, it is possible to increase the pressure at a position where the hydraulic pressure of the input port is low in the normal range, and the pressure increasing valve performs the pressure increasing operation.

According to the second aspect of the present invention, when the pressure increase is unnecessary, the valve seat is set to a position where the valve portion cannot be seated by the pressure increase inhibition control means. As a result, the pressure increasing valve cannot perform the pressure increasing operation, and the pressure increasing valve does not perform the pressure increasing operation. When pressure increase is required, the valve seat is set at a position where the valve portion can be seated. Thus, the pressure increasing valve can perform the pressure increasing operation, and the pressure increasing valve performs the pressure increasing operation.

Further, according to the third aspect of the invention, the operation of the pressure increase inhibition control means is controlled by any one of the negative pressure, the positive pressure air pressure, the hydraulic pressure and the electromagnetic force. Therefore, by appropriately controlling the negative pressure, the positive pressure air pressure, the liquid pressure, and the electromagnetic force, it is possible to disable the pressure increasing valve or to enable the pressure increasing valve.

Further, according to the present invention, the pressing force of the pressure increase inhibition control means is controlled by the hydraulic pressure from the hydraulic pressure generator. Therefore, the pressure increasing operation of the pressure increasing valve can be disabled or made possible without requiring any special power source. This simplifies the configuration and reduces costs.

According to the fifth aspect of the present invention, the valve plunger movement control means enables the valve plunger to move to such an extent that the pressure of the input port can be increased when the pressure increase is required. Thus, the pressure increasing valve can perform the pressure increasing operation, and the pressure increasing valve performs the pressure increasing operation.
Further, when pressure increase is not necessary, the movement of the valve plunger is prevented or restricted at least to such an extent that it is impossible to increase the hydraulic pressure at the input port. As a result, the pressure increasing valve cannot perform the pressure increasing operation, and the pressure increasing valve does not perform the pressure increasing operation.

Further, in the invention according to claim 6, the liquid chamber filled with the liquid is sealed by the control means when the pressure increase is unnecessary. As a result, the valve plunger cannot move, the pressure increasing valve cannot perform the pressure increasing operation, and the pressure increasing valve does not perform the pressure increasing operation. When the pressure increase is required, the liquid seal of the liquid chamber is released. As a result, the valve plunger can move, and the pressure increasing valve can perform the pressure increasing operation, so that the pressure increasing valve performs the pressure increasing operation.

According to the seventh aspect of the present invention, when the pressure increase is required, the unlocking portion is opposed to the opposite end of the valve plunger by the control means, so that the valve plunger can be moved for the pressure increasing operation. Become. Thus, the pressure increasing valve can perform the pressure increasing operation, and the pressure increasing valve performs the pressure increasing operation. When the pressure increase is unnecessary, the lock portion is opposed to the end on the opposite side of the valve plunger, and the movement required for the pressure increase operation of the valve plunger is prevented. As a result, the pressure increasing valve cannot perform the pressure increasing operation, and the pressure increasing valve does not perform the pressure increasing operation.

Further, in the invention according to claim 8, the communication control means shuts off the bypass passage connecting the input port side and the output port side when the pressure increase is required. As a result, the input port side and the output port side are connected only through the passage through which the valve plunger performs the pressure increasing operation. As a result, the output pressure from the output port is the input pressure increased by the pressure increasing action of the pressure increasing valve. When the pressure increase is unnecessary, the bypass passage is opened. Thereby, the input port side and the output port side are connected via the bypass passage. As a result, the effect of the pressure increasing valve of the pressure increasing valve is lost, and the output pressure is such that the input pressure is not increased.

Further, according to the ninth aspect of the present invention, the opening and closing of the bypass passage is controlled by controlling the valve piston by the hydraulic pressure from the hydraulic pressure generating device. Therefore, the pressure increasing operation of the pressure increasing valve can be disabled or made possible without requiring any special power source. This simplifies the configuration and reduces costs.

[0039]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a negative pressure brake booster system using a first example of an embodiment of a pressure increasing valve according to the present invention. The same components as those of the brake system shown in FIGS. 11 and 12 are denoted by the same reference numerals, and a detailed description thereof will be omitted.

The vacuum booster 12 of the vacuum brake booster system 11 of the first example shown in FIG. 1 is the same as the vacuum booster 12 shown in FIG. Yes, and the description is omitted.

As shown in FIG. 1, the pressure increasing valve 13 of the first example is, like the pressure increasing valve 13 shown in FIG. 12, a valve plunger 14 having a valve portion 14a and a valve portion 14a.
And a spring 19 that constantly biases the valve plunger 14 in a direction in which the valve portion 14a is separated from the valve seat 15. The spring force of the spring 19 has an input / output characteristic in which the pressure increasing valve 13 has a break point as shown in FIG. In that case, this first
The input / output characteristics of the example pressure-intensifying valve 13 are set at a position where the break point is lower than the input / output characteristics shown in FIG. 12C (a break point h in FIG. 2 described later). Hereinafter, regarding the break point in the description of the present invention, a low position means that the break point is set at a position where the input is small, and a high position means that the break point is set at a position where the input is large. . Therefore, in the pressure increase valve 13 of the first example, the pressure increase is set to start with a relatively small input.

The pressure increasing valve 13 shown in FIG.
Similarly, when the valve portion 14a is seated on the valve seat 15, the effective pressure receiving area on the MCY8 side of the valve plunger 14 is S1.
And the area of the non-pressure receiving portion of the valve plunger 14 is set to a value S2 smaller than the pressure receiving area S1.

Further, the pressure increasing valve 13 of the first example includes a pressure increasing inhibition control piston 20 for pressing the valve plunger 14. One surface 20 of this pressure increase inhibition control piston 20
At a, the atmospheric pressure is constantly applied via the hole 27 so as to press the pressure increase inhibition control piston 20 in the direction of the valve plunger 14. If it is not necessary to avoid the pressure change due to the operation of the pressure increase inhibition control piston 20 and the temperature, the hole 27 is omitted, and the positive pressure approximately equal to the atmospheric pressure is applied to one surface 20a of the pressure increase inhibition control piston 20. May always operate. Thus, even if the hole 27 is omitted and the one surface 20a side of the pressure increase inhibition control piston 20 is closed, the air is compressible.
A stroke necessary for control with 0 is secured.

On the other hand, the other surface 2 of the pressure increase inhibition control piston 20
0b is a negative pressure booster 12 in which a negative pressure is constantly introduced.
The negative pressure of the constant pressure chamber (not shown) is
Is acted in the direction away from the valve plunger 14, and the spring force of the spring 21 always acts in the direction away from the valve plunger 14.

Incidentally, one surface 2 of the pressure increase inhibition control piston 20
At 0a, the spring force of the spring 22 acts to oppose the spring force of the spring 21 to adjust the characteristics of the pressure-intensifying valve. However, the spring force of the spring 22 is not necessarily required.

Further, a hydraulic pressure sensor 23 for detecting the MCY pressure Pm and a negative pressure sensor 24 for detecting the negative pressure in the constant pressure chamber of the negative pressure booster 12 are provided.
Reference numerals 3 and 24 are both electrically connected to an electronic control unit (ECU) 25, and the MCY pressure Pm from the hydraulic pressure sensor 23 is provided.
And the negative pressure detection signal from the negative pressure sensor 24 are supplied to the ECU 25, respectively.
The ECU 25 also controls the drive motor 1 of the pressure increasing pump 17.
6 based on the respective detection signals from the hydraulic pressure sensor 23 and the negative pressure sensor 24, the MCY pressure Pm is set to the pressure at the break point h (shown in FIG. When the pressure becomes slightly higher, the operation of the drive motor 16, that is, the pressure increasing pump 17 is started.

The other configuration of the pressure increasing valve 13 of the first example and another configuration of the negative pressure brake booster system 11 are shown in FIG.
1 and those of FIG.

Next, the operation of the thus configured negative pressure brake booster system 11 will be described. If the negative pressure of the negative pressure source in the negative pressure brake booster system 11 is normal and the normal negative pressure is always introduced into the constant pressure chamber of the negative pressure booster 12, the negative pressure is applied to the pressure increase inhibition control piston. 20 acts on the other surface 20b. Atmospheric pressure or a positive pressure equivalent thereto is constantly applied to one surface 20a of the pressure increase inhibition control piston 20. For this reason, a large pressure difference is generated between both surfaces 20a and 20b of the pressure increase inhibition control piston 20, and the pressure increase inhibition control piston 20
, And presses the valve plunger 14 in the direction in which the valve portion 14a separates from the valve seat 15. Therefore, the valve portion 14a of the pressure increasing valve 13 is
5, the input port 13a is in communication with the output port 13b.

In this state, when the brake pedal 2 is depressed and the normal brake operation is performed, the control valve (not shown) of the negative pressure booster 12 is switched, similarly to the conventional negative pressure brake boosting system. As a result, the negative pressure booster 12 is activated to generate an output of a magnitude obtained by boosting the pedal depression force, and the output of the negative pressure booster 12 activates the piston (not shown) of the MCY 8 to cause the MCY 8 to operate. Generates the MCY pressure Pm, and the pressure liquid of the MCY pressure Pm is introduced into the input port 13 a of the pressure increasing valve 13. In that case, MCY8 constitutes the hydraulic pressure generator of the present invention. Further, the pressure fluid is supplied to the valve 1
It flows out of the output port 13b through the gap between the valve seat 4a and the valve seat 15 and flows into the W / C 10. In this way, the MCY pressure is supplied to the W / C 10 as the brake fluid pressure, and the normal service brake is applied. In this case, the pedaling force is boosted by the vacuum booster 12, so that the braking force is large.

At this time, the W / C pressure Pw, which is the output pressure from the output port 13b, is not controlled by the pressure increasing valve 13 and becomes the same as the MCY pressure Pm. That is,
W / C pressure Pw is the same size as MCY pressure Pm, and MCY pressure Pw
As shown in FIG. 2, the input / output characteristics of the pressure-intensifying valve 13 follow a straight line a inclined 45 degrees from the origin O as shown in FIG.

Further, the MCY pressure Pm acts on the valve plunger 14 in the direction in which the valve portion 14a is seated on the valve seat 15, that is, in the direction against the spring force of the spring 19, and the force is Pm × S2. Given. However, in the range of the MCY pressure Pm such that the force Pm × S2 acting on the valve plunger 14 becomes smaller than the sum of the spring force of the spring 19 and the pressing force from the pressure-inhibition control piston 20, the valve plunger 14 is moved in FIG. It does not move down. Similarly, when the MCY pressure Pm is in this range, the ECU 25 operates the pressure increasing pump 17 based on the detection signal of the MCY pressure Pm from the hydraulic pressure sensor 23 and the detection signal of the negative pressure from the negative pressure sensor 24. do not do. Therefore, the pressure increasing valve 13 does not perform the pressure increasing operation.

The MCY pressure Pm rises beyond the normal braking range, and the force Pm × S acting on the valve plunger 14
2 is the spring force of the spring 19 and the pressure-inhibiting control piston 2
When the pressure becomes larger than the sum of the pressing force applied to the valve plunger 14 and the valve plunger 14, the valve plunger 14 moves downward in FIG. The port 13a and the output port 13b are shut off.

On the other hand, when the MCY pressure Pm is
In the vicinity of the pressure at which the MCY pressure 4 is moved, the ECU 25 detects the MCY pressure Pm from the hydraulic pressure sensor 23,
The pressure increasing pump 17 is operated. As a result, FIG.
As in the case of the pressure increasing valve 13 and the pressure increasing pump 17 shown in FIG. 2A, the liquid discharged from the pressure increasing pump 17 is supplied to the W / C 10 and also supplied to the output port 13b of the pressure increasing valve 13. The pressure increasing valve 13 performs a pressure increasing operation. That is, the input / output characteristic of the pressure increasing valve 13 is represented by a straight line a
The characteristics are along a straight line b having a larger inclination. The relationship between the MCY pressure Pm and the W / C pressure Pw at this time is as follows:

[0054]

(Equation 2)

Is given by The slope of the straight line b is determined by the balance of the MCY pressure Pm applied to the valve plunger 14, the W / C pressure Pw, the spring force of the spring 19, and the pressing force from the pressure increase inhibition control piston 20. In addition, as shown in FIG.
Is a very high position.

Due to the pressure-intensifying action of the pressure-intensifying valve 13, the negative-pressure brake booster system 11 can increase the boost of the negative-pressure booster 12 when an extremely large braking force exceeding the normal braking range is required. Since the pressure increasing effect of the pressure increasing valve is added to the operation, a large W / C pressure Pw can be obtained, and the braking force becomes extremely large.

As described above, when the negative pressure is normal, the pressing force from the pressure-inhibiting control piston 20 is maximum on the valve plunger 14, and as shown in FIG. Will be set at a very high position. Therefore, when the MCY pressure Pm is within the range of the normal brake, the pressure-intensifying valve 13 does not perform the pressure-increasing operation, that is, in the region of the normal brake that does not require the pressure-increasing by the pressure-increasing valve 13, The prohibition control piston 20 prohibits the pressure increasing operation of the pressure increasing valve 13,
Further, when a large braking force exceeding the range of the normal brake is required, the pressure increasing operation of the pressure increasing valve 13 is performed.

When the negative pressure of the negative pressure source of the negative pressure brake booster system 11 is completely lost and the pressure drops to the atmospheric pressure, no differential pressure is generated between the two surfaces 20a and 20b of the pressure increase inhibition control piston 20. Therefore, the pressing force of the valve plunger 14 from the pressure increase inhibition control piston 20 is eliminated, and only the spring force of the spring 19 acts on the valve plunger 14. Then, the valve plunger 14 moves downward at a relatively small value of the MCY pressure Pm, and the valve portion 14a is seated on the valve seat 15. That is, as shown in FIG. 2, the break point h of the pressure increasing valve 13 in this case is set to a low position.
Therefore, when the MCY pressure Pm is a relatively small value, the pressure increasing valve 13 performs the pressure increasing operation along the straight line i. The slope of the straight line i is the same as the straight line b. As a result, when the negative pressure of the negative pressure source is lost and the boosting action of the negative pressure booster 12 is not performed and the boosting action of the Since the pressure increasing operation by the pressure increasing valve 13 is performed, W / C
The pressure Pw, that is, the brake pressure is rapidly increased, and the shortage of the braking force is compensated, so that the brake is reliably operated.

As described above, the pressure increasing valve 13 of the first example
According to the above, when the pressure increasing action is required, the pressure increasing valve 13
When the pressure increasing operation is not required, the pressure increasing effect of the pressure increasing valve 13 can be prohibited.

According to the negative pressure brake booster system 11 having the pressure increasing valve 13 of the first example, when the negative pressure of the negative pressure source fails, the pressure increasing valve 13 performs the pressure increasing operation.
It is possible to obtain a braking force equal to that at the time of normal negative pressure by compensating for the lack of the braking force, and to reliably operate the brake.

By changing at least one of the spring force of the spring 21 and the piston diameter of the pressure increase inhibition control piston 20, the pressing force of the pressure increase inhibition control piston 20 against the valve plunger 13 is appropriately controlled. As shown in FIG. 2, the breaking point of the pressure increasing valve 13 can be arbitrarily set to a breaking point d or a breaking point f, and the like.
Can be arbitrarily controlled (at this time, the pressure increase after the breakpoints d and f is represented by straight lines b and i, respectively).
Along the straight lines e and g having the same inclination as the above.) In that case, the valve plunger 13 of the pressure increase inhibition control piston 20
When the pressing force is increased, the break point moves to a higher position and the pressure boosting operation prohibition area widens, and when this pressing force is reduced, the break point moves to a lower position and the pressure boosting operation prohibition area increases. Narrows.

FIG. 3 is a view similar to FIG. 1 showing a negative pressure brake booster system having a second embodiment of the booster valve according to the present invention. The same components as those in the negative pressure brake booster system of the first example shown in FIG. 1 described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the above-described first example, the pressure-intensifying action of the pressure-intensifying valve 13 is prohibited in the normal brake region when the negative pressure of the negative pressure source is normal. In the booster system 11, the pressure-intensifying valve 13 performs a pressure-increasing operation even in a normal brake region when the negative pressure of the negative pressure source is normal.

That is, as shown in FIG. 3, the negative pressure brake booster system 11 is provided in a passage for applying the negative pressure of the constant pressure chamber of the negative pressure booster 12 to the other surface 20b of the pressure increase inhibition control piston 20. The electromagnetic switching valve 26 is provided. The electromagnetic switching valve 26 is connected to the other surface 20 of the pressure increase inhibition control piston 20.
A first position I for applying a negative pressure to b and a second position II for applying an atmospheric pressure are set, and are normally set to the first position I. The electromagnetic switching valve 26 is electrically connected to the ECU 25. The ECU 25 switches the electric switching valve 26 to the second position II when a pressure increasing condition for increasing the pressure of the pressure increasing valve 13 is input within the normal brake range. Other configurations of the first example are the same as those of the first example.

In the negative pressure brake booster system 11 of the second example configured as described above, for example, when the loading weight is large and a large braking force is required, the ECU 25 quickly applies a large brake for emergency braking operation. When a pressure increasing condition for a pressure increasing operation such as when a force is required is input, the ECU 25 switches the electric switching valve 26 to switch the second position.
Set to II. As a result, the pressure increase inhibition control piston 20
Atmospheric pressure is applied to the other surface 20b, the break point of the booster valve 13 is set to a break point h at a lower position, and the booster valve 13 is set within the normal brake area when the negative pressure of the negative pressure source is normal. By performing the pressure increasing operation, it is possible to reliably cope with the pressure increasing condition.

Further, not only in the case of a negative pressure failure, but also in the case of two or more brake systems, when at least one system fails, the electromagnetic switching valve 26 is switched.
It is also possible to perform pressure increasing action of other normal systems. Other operational effects of the second example are the same as those of the first example. Note that, instead of the electric switching valve 26, a switching valve that senses a negative pressure and switches mechanically can be used.

FIG. 4 is a view similar to FIG. 1, showing a negative pressure brake booster system having a third embodiment of the booster valve according to the present invention. Note that the same components as those of the negative pressure brake booster system of the first example shown in FIG. 1 are denoted by the same reference numerals, and a detailed description thereof will be omitted.

The pressure increasing valve 13 of the third example has exactly the same structure as the pressure increasing valve 13 of the first example shown in FIG. The type of pressure applied to the pressure inhibition control piston 20 and the operation state of the pressure are different. That is, the positive pressure air pressure of the pressure source 29 or the atmospheric pressure is selectively applied to one surface 20a of the pressure increase inhibition control piston 20 by the electromagnetic switching valve 30, and the atmospheric pressure is applied to the other surface 20b of the pressure increase inhibition control piston 20. Always works. The magnitude of the air pressure of the pressure source 29 is determined by the fact that this air pressure
b, the pressure-inhibiting control piston 20
However, the pressure is set to such an extent that a large pressing force equivalent to the pressing force of the pressure-inhibiting control piston 20 when the negative pressure is normal in the first example described above acts on the valve plunger 14.
Therefore, when the air pressure is acting on the one surface 20b of the pressure increase prohibition control piston 20, the break point of the pressure increasing valve 13 is a break point located at an extremely high position beyond the normal braking region as shown in FIG. is set to c.

The electromagnetic switching valve 30 includes a first position I in which the positive pressure of the pressure source 29 is applied to one surface 20a of the pressure-inhibition control piston 20;
A second position II at which atmospheric pressure acts on a is set, and is normally set to the first position I. Other configurations of the negative pressure brake booster system 11 of the third example are the same as those of the negative pressure brake booster system 11 of the first example.

In the negative pressure brake booster system 11 of the third example configured as described above, when the negative pressure in the constant pressure chamber of the negative pressure booster 12 is normal, the detection signal from the negative pressure sensor 24 is output. Accordingly, the ECU 25 sets the electromagnetic switching valve 30 to the first position I without switching. Therefore, the positive pressure of the pressure source 29 acts on the one surface 20a of the pressure-inhibition control piston 20, so that the pressure-inhibition control piston 20 pushes the valve plunger 14 to the valve portion 14 with an extremely large pressing force.
a is pressed in a direction away from the valve seat. Therefore, the break point of the pressure increasing valve 13 of the third example is set to a break point c at an extremely high position, and the pressure increasing valve 13 is prohibited from increasing its pressure in the normal braking region as in the first example. .

When the negative pressure in the constant pressure chamber of the negative pressure booster 12 is lost, the detection signal from the negative pressure sensor 24 causes
The CU 25 switches the electromagnetic switching valve 30 to set it to the second position II. For this reason, both sides 2 of the pressure increase inhibition control piston 20
No differential pressure is generated between 0a and 20b, and the pressure increase inhibition control piston 20 does not press the valve plunger 14. Therefore, as in the first example, the break point of the pressure-intensifying valve 13 becomes the position of the break point h at a lower position as shown in FIG.
The pressure increasing operation of the pressure increasing valve 13 is enabled.

Further, as in the case of the above-described second example, even in the normal braking region where the negative pressure is normal, the pressure increasing condition is determined by the ECU 25.
, The pressure-intensifying action of the pressure-intensifying valve 13 can be performed. Other functions and effects of the negative pressure brake booster system 11 of the third example are the same as those of the negative pressure brake booster system 11 of the first and second examples.

In the third example, the positive pressure of the pressure source 29 is used to control the operation of the pressure-inhibition control piston 20. However, the present invention is not limited to this. The operation of the pressure increase inhibition control piston 20 can also be controlled by negative pressure, hydraulic pressure, or electromagnetic force from a negative pressure source other than the negative pressure source.

FIG. 5 is a view similar to FIG. 1 showing a negative pressure brake booster system having a fourth embodiment of the booster valve according to the present invention. The same components as those of the negative pressure brake booster system of the third example shown in FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the pressure increasing valve 13 of the third example, a pressure increasing inhibition control piston 20 is provided, and when the pressure increasing inhibition control piston 20 presses the valve plunger 14, the pressure increasing operation of the pressure increasing valve 13 is performed. However, the pressure increasing valve 13 of the fourth example is not provided with the pressure increasing inhibition control piston 20 as shown in FIG. The pressure increasing valve 13 of the fourth example has a small-diameter end portion 14b of the valve plunger 14 opposite to the valve portion 14a.
Is provided in the chamber 28. This room 28 is M
It is connected to the reservoir 9 of the CY 8 and
The inside is filled with brake fluid.

Further, an electromagnetic on-off valve 48 is provided in a passage connecting the chamber 28 and the reservoir 9. The solenoid on-off valve 48 is provided at a first position I at which communication between the chamber 28 and the reservoir 9 is interrupted, and at a second position I at which communication between the chamber 28 and the reservoir 9 is established.
I is set, and is normally set to the first position I. When the solenoid on-off valve 48 is set to the first position I, the chamber 2
When the communication between the reservoir 8 and the reservoir 9 is cut off,
Is sealed at atmospheric pressure. And the electromagnetic on-off valve 4
Reference numeral 8 is electrically connected to the ECU 25 similarly to the electromagnetic switching valve 30 of the third example, and is switched by a control signal from the ECU 25. Another configuration of the pressure increasing valve 13 of the fourth example and the negative pressure brake booster system 1
The other configuration of 1 is the same as that of the third example.

In the negative pressure brake booster system 11 of the fourth example configured as described above, when the negative pressure in the constant pressure chamber of the negative pressure booster 12 is normal, the detection signal from the negative pressure sensor 24 is output. Accordingly, the ECU 25 sets the electromagnetic opening / closing valve 48 to the first position I without switching, so that the interior of the chamber 28 is sealed at atmospheric pressure. In this state, regardless of the magnitude of the MCY pressure Pm, the valve plunger 14 cannot move and is completely locked. Therefore, the valve portion 14a does not sit on the valve seat 15, and the input port 13a and the output port 13b are always in communication with each other.
The pressure increasing valve 13 does not perform any pressure increasing operation, no matter how much the MCY pressure Pm increases.

When the negative pressure in the constant pressure chamber of the negative pressure booster 12 is lost, the detection signal from the negative pressure sensor 24 causes
The CU 25 switches the electromagnetic on-off valve 48 to set it to the second position II. For this reason, since the chamber 28 and the reservoir 9 communicate with each other, the liquid seal of the chamber 28 is released, and the valve plunger 14 becomes movable. That is, the pressure-intensifying valve 13 has a break point, so that the pressure-increasing action can be performed. This break point is a break point h at a lower position shown in FIG. 2, and the MCY pressure Pm
Is relatively small, the pressure increasing valve 13 performs the pressure increasing operation. Other operational effects of the negative pressure brake booster system 11 of the fourth example are the same as those of the negative pressure brake booster system 11 of the first example.

FIG. 6 is a view similar to FIG. 5, showing a negative pressure brake booster system having a fifth embodiment of the booster valve according to the present invention. The same components as those of the negative pressure brake booster system of the fourth example shown in FIG. 5 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the pressure increasing valve 13 of the fourth example, a chamber 28 is provided in which the small-diameter end portion 14b of the valve plunger 14 is disposed, and the chamber 28 is liquid-sealed to lock the movement of the valve plunger 14. But this 5th
As shown in FIG.
Numeral 1 faces the small-diameter end 14b of the valve plunger 14 and is located within the movement area of each small-diameter end 14b. The lock pin 31 is provided with a lock portion 31a and a lock release portion 31b formed of a cutout recess. The lock pin 31 is made movable forward and backward by a predetermined amount by an electromagnetic solenoid 32.

The electromagnetic solenoid 32 is electrically connected to the ECU 25, and its operation is controlled by the ECU 25. In the normal state where the negative pressure of the negative pressure source of the negative pressure booster 12 is normal, the ECU 25 moves the lock pin 31 to the first position where the lock portion 31a faces the small diameter side end portion 14b of the valve plunger 14 as shown in the figure. When the valve plunger 14 is set to the first position, the movement of the valve plunger 14 by a predetermined amount or more is prevented. This valve plunger 1
In the movement inhibition state of No. 4, the state is exactly the same as the locked state at the time of liquid sealing of the chamber 28 of the fourth example described above, so that the valve portion 14 does not sit on the valve seat 15. Also,
When the negative pressure of the negative pressure source has failed, the ECU 25 sets the lock pin 31 to the second position where the lock release portion 31b faces the small-diameter side end portion 14b of the valve plunger 14, as shown in FIG. The movement of the plunger 14 is allowed. In the movement allowable state of the valve plunger 14, the same state as the unlocked state at the time of releasing the liquid seal of the chamber 28 of the fourth example described above is obtained, and the valve portion 14 is
It is possible to sit on. This fifth example of the pressure increasing valve 13
Other configurations and the other configurations of the negative pressure brake booster system 11 are the same as those of the first example.

In the thus configured negative pressure brake booster system 11 of the fifth example, when the negative pressure in the constant pressure chamber of the negative pressure booster 12 is normal, the detection signal from the negative pressure sensor 24 is output. Accordingly, the ECU 25 does not operate the electromagnetic solenoid 32 and sets the lock pin 31 to the first position. In this state, the valve plunger 14 is connected to the chamber 2 of the fourth example described above.
The state becomes exactly the same as the locked state at the time of liquid sealing of No. 8, the pressure increasing valve 13 has no break point, and no pressure increasing action is performed at all, no matter how much the MCY pressure Pm increases.

When the negative pressure in the constant pressure chamber of the negative pressure booster 12 fails, the detection signal from the negative pressure sensor 24 causes
The CU 25 operates the electromagnetic solenoid 32 to set the lock pin 31 to the second position. In this state, the valve plunger 14 becomes exactly the same as the unlocked state when the liquid seal of the chamber 28 of the fourth example is released, and the pressure increasing valve 13
Has a break point h shown in FIG. 2, and performs the pressure increasing operation at a relatively small value of the MCY pressure Pm. Other functions and effects of the negative pressure brake booster system 11 of the fifth example are the same as those of the negative pressure brake booster system 11 of the first example.

FIG. 7 is a diagram partially showing a negative pressure brake booster system having a sixth embodiment of the pressure increasing valve according to the present invention. The same reference numerals are given to the same components as those in the negative pressure brake booster system of the above-described fourth example, and a detailed description thereof will be omitted.

As shown in FIG. 7, the pressure increasing valve 13 of the sixth embodiment has a valve plunger 14 on the opposite side of the valve portion 14a.
Is provided with a stepped pressure-inhibiting control piston 20 which is cylindrical and has a step on the small-diameter portion 14b side. This pressure increase inhibition control piston 20
The small-diameter portion 14b is loosely fitted to the small-diameter portion 14b such that the small-diameter portion 14b passes through the center through hole 20a. In that case,
The small diameter end 20b of the pressure increase inhibition control piston 20 is
a small-diameter end portion 20b
Between the valve plunger 14 and the valve plunger 14
A spring 19 for urging the spring 4 is contracted. Also,
The end of the small diameter end 20b is the step 14 of the valve plunger 14.
c can be contacted.

On the other hand, the diameter of the large diameter end 20c of the pressure increase inhibition control piston 20 is set to be larger than the diameter S1 of the valve portion 14a and the diameter of the small diameter end 20b. Further, the right end face of the large diameter end portion 20c is always in communication with the output port 13b through the central through hole 20a of the pressure increase inhibition control piston 20.

The small-diameter end portion 20 of the pressure increase inhibition control piston 20
b and the pressure receiving area S4 of the large-diameter end portion 20c.
Is between the pressure receiving area S1 of the valve plunger 14 on the MCY8 side when seated on the valve seat 15 of the valve portion 14a and the area S2 of the non-pressure receiving portion of the valve plunger 14 (S4-
S3)> (S1-S1).

The large-diameter end portion 20c and the small-diameter portion 20b have a stepped portion 20d which selectively communicates with the MCY 8 or the reservoir 9 of the MCY 8. The communication between the step 20d and the MCY 8 or the reservoir 9 is controlled by the first and second solenoid on-off valves 33 and 34, respectively.

The first solenoid on-off valve 33 is connected to the stepped portion 20d and the MC
A first position I for blocking Y8, a stepped portion 20d and MCY8.
Is set to a first position I, which is normally closed, and the valve is normally closed. In addition, the second electromagnetic on-off valve 34 has a first position I that connects the step portion 20d and the reservoir 9 and a second position II that shuts off the step portion 20d and the reservoir. It is set to 1 position I and is normally open. Therefore, the step portion 20 d is normally communicated with the reservoir 9 at normal times. These first and second solenoid on-off valves 33, 34 are respectively provided by ECU
25 is electrically connected. Another configuration of the pressure increasing valve 13 of the sixth example and the negative pressure brake booster system 11
The other configuration is the same as that of the fourth example.

In the negative pressure brake booster system 11 of the sixth example configured as described above, when the negative pressure in the constant pressure chamber of the negative pressure booster 12 is normal, the detection signal from the negative pressure sensor 24 is output. Accordingly, the ECU 25 sets the first and second electromagnetic on-off valves 33, 34 to the first position I without operating both. In this state, the stepped portion 2 of the pressure increase inhibition control piston 20
0d communicates with the reservoir 9, and atmospheric pressure acts on the step 20d. Further, the valve plunger 14 is in a state where the valve portion 14a is separated from the valve seat 15 as described above.

In this state, when the normal brake operation is performed, the MCY pressure Pm is changed to the input port 13a and the
It is introduced into the W / C 10 through the gap between the valve portion 14a and the valve seat 15 and the output port 13b, and the normal brake is operated. At this time, the MCY pressure Pm that has passed through the gap between the valve portion 14a and the valve seat 15 acts on the small-diameter end portion 20b of the pressure increase inhibition control piston 20, and the pressure increase inhibition control piston 2
0 through the central through hole 20a to act on the large diameter end 20c. Atmospheric pressure acts on the step 20d of the large diameter end 20c. For this reason, a force difference is generated between both ends of the pressure increase inhibition control piston 20 due to the action of the MCY pressure Pm.
4 and the respective areas of the pressure increase inhibition control piston 20 are (S4
−S3)> (S1−S2), so that the pressure increase prohibition control piston 20 is urged leftward in the drawing, that is, toward the valve portion 14a. As a result, the pressure increase inhibition control piston 20 presses the valve plunger 14 in the same direction via the spring 19.

On the other hand, the MCY pressure Pm passing through the input port 13a acts on the small-diameter portion 14a of the valve plunger 14 in the same manner as described above, so that the valve portion 14a Power is occurring,
This force is smaller than the pressing force of the pressure increase inhibition control piston 20 on the valve plunger 14. Therefore, since the valve plunger 14 does not move rightward in the figure, the valve portion 1
4a does not sit on the valve seat 15. That is, the valve plunger 14 is locked. And
Since the difference between these forces increases as the MCY pressure Pm increases, the more the MCY pressure Pm increases,
The valve plunger 14 is more securely locked. When the MCY pressure Pm rises above a predetermined pressure, the small-diameter end portion 20b of the pressure-intensification prohibition control piston 20 comes into contact with the step portion 14c of the valve plunger 14. As a result, the valve plunger 14 is directly pressed.

Thus, when the negative pressure in the constant pressure chamber of the negative pressure booster 12 is normal, the valve plunger 14 becomes exactly the same state as the above-described locked state of the chamber 28 at the time of liquid sealing, The pressure intensifying valve 13 has no break point, and MCY
No matter how large the pressure Pm becomes, no pressure boosting action is performed.

When the negative pressure in the constant pressure chamber of the negative pressure booster 12 is lost, a detection signal from the negative pressure sensor 24
The CU 25 operates the first and second solenoid on-off valves 33 and 34 to set each of them to the second position II. Therefore, the step portion 20d of the pressure increase inhibition control piston 20 is disconnected from the reservoir 9 and communicates with the MCY 8.

When a normal brake operation is performed in this state, the generated MCY pressure Pm is introduced into the W / C 10 in the same manner as described above, and the valve portion 14a, the small-diameter end portion 20b of the pressure increase inhibition control piston 20, and the large Although it acts on the radial end portion 20c, it also acts on the step portion 20d of the pressure increase inhibition control piston 20 rightward through the first solenoid on-off valve 33. For this reason, even if the MCY pressure Pm acts between both ends of the pressure increase inhibition control piston 20, there is no difference in force, and the pressure increase inhibition control piston 20 is not energized by the action of the MCY pressure Pm. . As a result, the pressure-inhibition control piston 20 does not press the valve plunger 14 at all, and the valve plunger 14 becomes exactly the same as the unlocked state when the liquid seal of the chamber 28 of the fourth example is released, and the pressure is increased. The pressure valve 13 has a break point h shown in FIG. 2, and the pressure increasing operation is started when the MCY pressure Pm is relatively small. Other operational effects of the negative pressure brake booster system 11 of the sixth example are the same as those of the negative pressure brake booster system 11 of the fourth example.

In the sixth example, the MCY pressure Pm is applied to the step 20d by the first and second solenoid on-off valves 33 and 34.
Alternatively, the atmospheric pressure of the reservoir 9 is selectively actuated. However, the present invention is not limited to this. For example, the second solenoid valve 34 may be omitted, and a stroke absorbing piston 46 shown in FIG. You can also do so.

FIG. 8 is a diagram partially showing a negative pressure brake booster system having a seventh embodiment of the pressure increasing valve according to the present invention. The same components as those of the above-described sixth example of the negative pressure brake booster are denoted by the same reference numerals, and a detailed description thereof will be omitted.

In the sixth example shown in FIG. 7 described above, a pressure increase inhibition control piston 20 that presses the valve plunger 14 is provided.
The CY pressure Pm and the atmospheric pressure are compared with the first and second solenoid on-off valves 3
The negative pressure brake booster system 11 of the seventh example is not provided with the pressure increase inhibition control piston 20 as shown in FIG. A bypass passage 35 that connects the MCY 8 and the output side of the pressure increasing valve 13 by bypassing the pressure increasing valve 13 in place of the control piston 20;
5 is provided.

The bypass valve 36 is connected to the bypass passage 35
And a spring 38 that constantly urges the valve piston 37 with a relatively weak force in a direction to shut off the bypass passage 35. Then, the small diameter side end 37a of the valve piston 37
The MCY pressure Pm acts on the large-diameter end 37 b of the valve piston 37.
As in the case of the step portion 20d of the pressure increase inhibition control piston 20 in the example, the MCY pressure Pm and the atmospheric pressure are selectively actuated by the first and second solenoid on-off valves 33 and 34. Atmospheric pressure is applied. Other configurations of the pressure increasing valve 13 of the seventh example and other configurations of the negative pressure brake booster system 11 are the same as those of the sixth example.

In the negative pressure brake booster system 11 of the seventh example having the above-described configuration, when the negative pressure in the constant pressure chamber of the negative pressure booster 12 is normal, the first pressure is increased in the same manner as in the sixth example. The second solenoid on-off valves 33 and 34 are both set to the first position I. In this state, the atmospheric pressure is applied to the large-diameter end 37 b of the valve piston 37.

In this state, when the normal brake operation is performed, the MCY pressure Pm is applied to the input port 13 as in the sixth example.
a, is introduced into the W / C 10 through the gap between the valve portion 14a and the valve seat 15 and the output port 13b, and the normal brake is operated.
At this time, the MCY pressure Pm also acts on the small-diameter end 37a of the valve piston 37, so that the valve piston 37 moves leftward in the figure against the relatively weak spring force of the spring 38, The bypass passage 35 is opened. Therefore, the MCY 8 and the output port 13 of the pressure increasing valve 13
b directly communicates with the pressure increasing valve 13 bypassing the pressure increasing valve 13.

In this state, when the MCY pressure Pm increases, the valve plunger 14 moves rightward, and the valve portion 14a
Is seated on the valve seat 15. However, MC
Since Y8 is in direct communication with the output port 13b of the pressure increasing valve 13, that is, the W / C 10, through the bypass passage 35, the operation of the pressure increasing valve 13 has no relation. For this reason, the W / C pressure Pw is not increased no matter how much the MCY pressure Pm increases, and increases along the straight line a in FIG. 2 with the same magnitude as the MCY pressure Pm as the MCY pressure Pm increases. Become like Thus, when the negative pressure of the negative pressure booster 12 is normal, the state becomes exactly the same as the state in which the pressure increasing operation of the pressure increasing valve 13 is prohibited.

When the negative pressure of the negative pressure booster 12 is lost, the first and second electromagnetic opening / closing valves 33,
34 are respectively set to the second position II. For this reason,
The large-diameter end 37 b of the valve piston 37 is connected to the reservoir 9.
And is communicated with MCY8.

When the normal brake operation is performed in this state, the generated MCY pressure Pm is reduced to W / C10 in the same manner as described above.
And acts on the small-diameter end 37a of the valve piston 37.
7 also acts on the large-diameter end 37b. For this reason, a force for urging the valve piston 37 rightward is generated in the valve piston 37, so that the bypass passage 35 is maintained in a closed state. Therefore, MC
Y8 communicates only with the W / C 10 via the pressure-intensifying valve 13, and the W / C pressure Pw is compared with the MCY pressure Pm by the pressure-intensifying action of the pressure-intensifying valve 13 having a break point h shown in 2. The pressure is increased by a relatively small value. Another operation and effect of the negative pressure brake booster system 11 of the seventh example is as follows.
It is the same as the negative pressure brake booster system 11 of the example.

FIG. 9 is a diagram partially showing a negative pressure brake boosting system having an eighth embodiment of the pressure increasing valve according to the present invention. The same components as those of the negative pressure brake booster system of the sixth example shown in FIG. 7 described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the sixth example shown in FIG. 7, the valve seat 15 is fixed, and the pressure-intensifying prohibition control piston 20 presses the valve plunger 14, thereby inhibiting the pressure-intensifying valve 13 from increasing the pressure. However, in the negative pressure brake booster system 11 of the eighth example, when the valve seat 15 is made movable as shown in FIG. The piston 20 separates the valve plunger 14 from the valve plunger 14 so that the valve portion 14a of the valve plunger 14b is not seated on the valve seat 15.

The pressure-intensifying valve 13 of the eighth example will be specifically described. A valve plunger 14 is formed in a cylindrical shape, and a valve seat 15 is provided so as to be movable in the axial direction. 15 is a stepped pressure increase inhibition control piston 20
The connection member 39 is connected so as to be relatively movable and the relative movement amount is regulated to a predetermined amount or less. Also,
Valve seat 15 and small-diameter end 20 of pressure-inhibiting control piston 20
A spring 40 is contracted between the spring member 40b and the spring 40, and is normally kept at a maximum distance by a predetermined amount regulated by the connecting member 39 by the spring force of the spring 40.

The large-diameter end 20a of the pressure-inhibition control piston 20 is arranged in a chamber 41, which is
It can communicate with CY8. The communication between the MCY 8 and the chamber 41, the cutoff is performed by the first solenoid on-off valve 33 (in this example, only one solenoid on-off valve is provided,
Since it is exactly the same as the on-off valve 33, it is denoted by the first), and the chamber 41 is normally shut off from the MCY 8 and is in a liquid sealed state at a pressure equivalent to the atmospheric pressure. It has become.

The pressure increase prohibition control piston 20 is constantly urged leftward in the figure by the spring force of a spring 42 disposed in the chamber 41. When not operating, the step portion 20e of the pressure increase prohibition control piston 20 is turned off. The first fixed to the housing 43
The piston 2 is brought into contact with the end of the cylindrical member 44 and
The movement of 0 to the left is restricted. In the state where the stepped portion 20e of the pressure increase inhibition control piston 20 is in contact with the end of the first tubular member 44, as shown in the drawing, between the valve portion 14a of the valve plunger 14 and the valve seat 15, , The same gap as the gap between the valve portion 14a and the valve seat 15 is set.

As described above, when the valve portion 14a and the valve seat 15 are separated from each other, the input port 13a is provided at the center through hole 14e of the valve plunger 14, the gap between the valve portion 14a and the valve seat 15, the first cylindrical shape. A connection is made to the output port 13b through a radial hole 44a formed in the member 44 and an axial groove 45a formed on the outer periphery of the second cylindrical member 45.

Further, a step 14f is provided on the outer periphery of the valve plunger 14, and when the valve plunger 14 moves rightward, the step 14f is
4 can be abutted. In other words, the axial movement distance of the valve plunger 14 is restricted between the illustrated leftmost position and the rightmost position where the step 14f abuts on the end of the first tubular member 44. On the other hand, the pressure increase inhibition control piston 20
Is restricted between the leftmost limit position shown in the figure and the rightmost position where the right end of the pressure increase inhibition control piston 20 abuts the housing 43. The axial movement distance of the pressure increase inhibition control piston 20 is set to be longer than the axial movement distance of the valve plunger 14. As a result, the valve portion 14a is moved from the valve seat 15
It can be set to a non-seatable state.

At the right end of the pressure-inhibition control piston 20, when the chamber 41 is in a liquid-sealed state, the pressure-inhibition control piston 2
Stroke absorbing piston 4 that allows rightward movement of 0
6 is contacted by a spring 47. The rightward end 46a of the stroke absorbing piston 46 abuts on the housing 43, so that the rightward movement thereof is regulated to a predetermined amount. Other configurations of the eighth example negative pressure brake booster system 11 are the same as those of the sixth example.

In the negative pressure brake booster system 11 of the eighth example configured as above, when the negative pressure in the constant pressure chamber of the negative pressure booster 12 is normal, the first pressure is increased in the same manner as in the sixth example. The solenoid on-off valve 33 is set to the first position I. In this state, the chamber 41 is shut off from the MCY 8 and is in a liquid-sealed state,
A pressure equal to the atmospheric pressure acts on the large-diameter end portion 20a of the pressure increase inhibition control piston 20.

In this state, when the normal brake operation is performed, the MCY pressure Pm is applied to the input port 13a, the central through hole 14e,
W / C1 through the gap between the valve portion 14a and the valve seat 15, the radial hole 44a, the axial groove 45a, and the output port 13b.
0 and the brake normally operates. At this time, the MCY pressure Pm that has passed through the gap between the valve portion 14a and the valve seat 15 is
This acts on the small-diameter end portion 20b of the pressure increase inhibition control piston 20. For this reason, the pressure increase inhibition control piston 20
In the drawing, it is urged rightward, that is, in a direction away from the valve portion 14a, and moves rightward. At this time, although the chamber 41 is in the liquid-sealed state, since the stroke absorption piston 46 moves to the right, the pressure increase inhibition control piston 20 easily moves to the right. As a result, the valve seat 15 moves in a direction away from the valve portion 14a.

When the MCY pressure Pm increases and reaches the pressure at the break point h shown in FIG. 2, the valve plunger 14 moves to the right, that is, toward the valve seat 15, but as the MCY pressure Pm increases, the pressure increase inhibition control is performed. Since the piston 20 and the valve seat 15 also move rightward, the valve portion 14a does not sit on the valve seat 15. The MCY pressure Pm further rises, and the valve plunger 1
4 moves further rightward, and when the step 14f abuts on the end of the first cylindrical member 44, the valve plunger 14 does not move any further even if the MCY pressure Pm further increases. on the other hand,
As the MCY pressure Pm further rises, the pressure increase inhibition control piston 20 and the valve seat 15 move further rightward, so that the valve portion 14a does not sit on the valve seat 5 at all.

When the negative pressure in the constant pressure chamber of the negative pressure booster 12 is normal, the valve portion 14a and the valve seat 15
The locked state of the example valve plunger 14 is exactly the same, the booster valve 13 has no break point, and MC
No matter how large the Y pressure Pm becomes, no pressure increasing action is performed.

When the negative pressure in the constant pressure chamber of the negative pressure booster 12 fails, the first solenoid on-off valve 33 is similarly set to the second position II. Therefore, the liquid sealing state of the chamber 41 is released, and the chamber 41 is connected to the MCY 8.

When the normal brake operation is performed in this state, the generated MCY pressure Pm is introduced into the W / C 10 in the same manner as described above, and acts on the small-diameter end portion 20b of the pressure increase inhibition control piston 20. However, it further acts on the large-diameter end 20a of the pressure increase inhibition control piston 20 to the left through the first electromagnetic opening / closing valve 33. For this reason, a force difference occurs between both ends of the pressure increase inhibition control piston 20 due to the action of the MCY pressure Pm, and the pressure increase inhibition control piston 20 is urged to the left. As a result, the pressure increase prohibition control piston 20 is held at the leftmost position shown in the drawing in which the stepped portion 20e is in contact with the right end of the first tubular member 44. In this state, the pressing force from the pressure-intensifying prohibition control piston 20 does not act on the valve seat 15 at all, and the gap between the valve portion 14a and the valve seat 15 is the regular gap of the pressure-intensifying valve 13 as described above. Is held. Accordingly, the pressure-intensifying valve 13 is in exactly the same state as the state in which the pressure-inhibiting control piston 20 in the sixth example does not press the valve plunger 14 at all, and the pressure-increasing valve 13 has a break point h shown in FIG. As a result, the pressure increasing operation starts at a relatively small value of the MCY pressure Pm. Other functions and effects of the negative pressure brake booster system 11 of the eighth example are the same as those of the negative pressure brake booster system 11 of the sixth example.

In the eighth embodiment, the chamber 41 is in a liquid-sealed state, and the stroke of the pressure increase inhibition control piston 40 is made possible by the stroke absorbing piston 46. However, the present invention is not limited to this. As shown in the sixth example, a second electromagnetic on-off valve 34 is also provided, and the chamber 41 is controlled by the first and second electromagnetic on-off valves 33 and 34 to MCY8 or MCY8.
8 may be selectively connected to the reservoir 9.

In the above description, the present invention is applied to the negative pressure brake booster system 11, but the present invention is not limited to this, and the present invention is not limited to this. It can be applied to a brake booster system of various power sources such as an air pressure brake booster system, or a brake booster system with various types of brake boosters even with the same power source. Also applicable to no brake system. Further, the present invention can be applied to other hydraulic systems (with or without a booster) other than the brake system.

[0121]

As is apparent from the above description, according to the pressure-intensifying valve of the present invention, the pressure-intensifying action can be reliably performed when the pressure-intensifying action is required, and the pressure-increasing action is not required. When necessary, it is possible to reliably prevent the pressure increasing operation from being performed. Therefore, in various brake operating conditions required for the brake booster system, for example, in the loaded state of the vehicle, emergency brake operation, or a malfunction state of the booster function of the hydraulic booster or the negative pressure booster, the booster valve is provided. It is possible to flexibly and surely cope with the case where the pressure increasing action is required and the case where the pressure increasing action is not required.

[Brief description of the drawings]

FIG. 1 is a diagram showing a negative pressure brake boosting system using a first example of an embodiment of a pressure increasing valve according to the present invention.

FIG. 2 is a graph showing input / output characteristics of first to eighth examples and a conventional example.

FIG. 3 is a diagram showing a negative pressure brake boosting system using a second example of the embodiment of the present invention.

FIG. 4 is a diagram showing a negative pressure brake boosting system using a third example of an embodiment of the present invention.

FIG. 5 is a diagram partially showing a negative pressure brake boosting system using a fourth example of an embodiment of the present invention.

FIG. 6 is a diagram partially showing a negative pressure brake booster system using a fifth example of an embodiment of the present invention.

FIG. 7 is a diagram showing a negative pressure brake boosting system using a sixth example of an embodiment of the present invention.

FIG. 8 is a diagram partially showing a negative pressure brake boosting system using a seventh example of the embodiment of the present invention.

FIG. 9 is a diagram partially showing a negative pressure brake boosting system using an eighth embodiment of the present invention.

FIG. 10 is a diagram showing a conventional general hydraulic brake booster system.

FIG. 11 is a view showing a conventional general negative pressure brake booster system.

FIG. 12 is a diagram showing an example of a conceivable brake system for increasing the brake fluid pressure without using a booster.

[Explanation of symbols]

2… Brake pedal, 8… Master cylinder (MCY),
9: reservoir, 10: wheel cylinder (W / C), 1
1 ... Negative pressure brake booster system, 12 ... Negative pressure booster,
13 ... Pressure increasing valve, 14 ... Valve plunger, 14a ...
Valve part, 15 ... Valve seat, 17 ... Pump for increasing pressure, 19, 21, 3
8, 40, 42, 47 ... spring, 20 ... pressure increase inhibition control piston, 23 ... hydraulic pressure sensor, 24 ... negative pressure sensor, 25
... Electronic control unit (ECU), 26, 30, 48 ... electromagnetic switching valve, 28, 41 ... chamber, 29 ... pressure source, 31 ... lock pin, 32 ... electromagnetic solenoid, 33 ... first electromagnetic on-off valve, 3
4 ... second electromagnetic on-off valve, 35 ... bypass passage, 36 ... bypass valve, 37 ... valve piston, 39 ... connecting member,
43: Housing, 44: First cylindrical member, 45: Second cylindrical member, 46: Stroke absorbing piston

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hidefumi Inoue 2-11-6 Shinmeicho, Higashimatsuyama-shi, Saitama Automobile Equipment Co., Ltd. Matsuyama Plant (72) Inventor Mamoru Sawada 1-1-1 Showacho, Kariya-shi, Aichi Prefecture Address: Inside Denso Corporation (72) Inventor Shuichi Yonemura 1-1-1, Showa-cho, Kariya City, Aichi Prefecture Inside Denso Corporation (72) Inventor Takahiro Goshima 1-1-1, Showa-cho, Kariya City, Aichi Prefecture Inside Denso Corporation

Claims (9)

[Claims] 1. An input port into which a hydraulic pressure from a hydraulic pressure generator is introduced, an output port through which an output hydraulic pressure is derived and a pressure increasing hydraulic pressure from a pressure increasing hydraulic pressure source is introduced, and the input port When the hydraulic pressure of the input port is smaller than the predetermined pressure, the input port and the output port communicate with each other, and the hydraulic pressure of the input port is derived from the output port as the output hydraulic pressure. When the pressure is equal to or higher than the predetermined pressure, the pressure between the input port and the output port is shut off, and the hydraulic pressure of the input port is increased by introducing the pressure increasing hydraulic pressure to the output port. A valve plunger derived from the output port as an output hydraulic pressure, and when a pressure increase is unnecessary, a pressing force is applied to the valve plunger so as to oppose the hydraulic pressure of the input port, thereby inhibiting the pressure increase effect and increasing the pressure. When necessary, release the action of the pressing force on the valve plunger. And a pressure-inhibition control means for performing a pressure-increasing operation. 2. An input port to which a hydraulic pressure from a hydraulic pressure generator is introduced, an output port to derive an output hydraulic pressure and to receive a hydraulic pressure from a hydraulic pressure source, and the input port. When the hydraulic pressure of the input port is smaller than the predetermined pressure, the input port and the output port communicate with each other, and the hydraulic pressure of the input port is derived from the output port as the output hydraulic pressure. When the pressure is equal to or higher than the predetermined pressure, the pressure between the input port and the output port is shut off, and the hydraulic pressure of the input port is increased by introducing the pressure increasing hydraulic pressure to the output port. A valve plunger derived from the output port as an output hydraulic pressure, and when the pressure increase is not required, the valve seat is set to a position where the valve section cannot be seated to inhibit the pressure increase action, and when the pressure increase is required, the valve seat Is set at a position where the valve section can be seated so as to perform a pressure increasing action. And a stop control means. 3. The operation of the pressure increase prohibition control means includes the steps of:
The pressure increasing valve according to claim 1, wherein the pressure is controlled by any one of a positive air pressure, a hydraulic pressure, and an electromagnetic force. 4. The pressure-intensifying valve according to claim 1, wherein the pressure by the pressure-inhibiting control means is controlled by a hydraulic pressure from the hydraulic pressure generating device. 5. An input port to which a hydraulic pressure from a hydraulic pressure generator is introduced, an output port to derive an output hydraulic pressure and to receive a hydraulic pressure for pressure increase from a hydraulic pressure source for pressure increase, and the input port. When the hydraulic pressure of the input port is smaller than the predetermined pressure, the input port and the output port communicate with each other, and the hydraulic pressure of the input port is derived from the output port as the output hydraulic pressure. When the pressure is equal to or higher than the predetermined pressure, the liquid is moved to shut off the connection between the input port and the output port, and the hydraulic pressure of the input port is increased by introducing the pressure increasing hydraulic pressure to the output port. A valve plunger for deriving pressure from the output port as the output hydraulic pressure, and a valve plunger that can be moved to such an extent that the pressure of the input port can be increased when pressure increase is required. When necessary, set the valve plunger at least at the input port hydraulic pressure. A valve plunger movement control means for preventing movement or restricting movement to such an extent that pressure increase cannot be performed. 6. The valve plunger movement control means,
An end of the valve plunger opposite to the end of the input port on which the hydraulic pressure acts is disposed and a liquid chamber filled with liquid, and the liquid chamber is liquid-sealed when pressure increase is unnecessary. 6. The pressure increasing valve according to claim 5, further comprising control means for releasing a liquid seal of the liquid chamber when the pressure increasing is required to bring the liquid chamber into an atmospheric pressure state. 7. The valve plunger movement control means,
A lock member disposed opposite to an end of the valve plunger on the side of the input port on which the hydraulic pressure acts, and having a lock portion and a lock release portion; The unlocking portion is opposed to the opposite end of the valve plunger to enable the valve plunger to move for the pressure increasing operation, and when the pressure increasing is unnecessary, the lock portion is moved to the position of the valve plunger. 6. A control means for controlling the operation of the lock member so as to oppose the opposite end to prevent the valve plunger from moving for pressure increasing operation.
Pressure booster valve as described. 8. An input port to which a hydraulic pressure from a hydraulic pressure generator is introduced, an output port to derive an output hydraulic pressure and to receive a hydraulic pressure from a hydraulic pressure source, and the input port. When the hydraulic pressure of the input port is smaller than the predetermined pressure, the input port and the output port communicate with each other, and the hydraulic pressure of the input port is derived from the output port as the output hydraulic pressure. When the pressure is equal to or higher than the predetermined pressure, the pressure between the input port and the output port is shut off, and the hydraulic pressure of the input port is increased by introducing the pressure increasing hydraulic pressure to the output port. A valve plunger derived from the output port as an output hydraulic pressure, a bypass passage connecting the input port side and the output port side by bypassing a path in which the valve plunger performs a pressure increasing operation, While shutting off the bypass passage, when pressure increase is unnecessary A pressure-intensifying valve, comprising: a communication control means for communicating with the bypass passage that opens the bypass passage. 9. The communication control means according to claim 8, wherein said communication control means comprises a bypass valve having a valve piston controlled by a hydraulic pressure from said hydraulic pressure generating device to open and close said bypass passage. Pressure booster valve as described.