JP2001138895A - Hydraulic brake device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture and assemble easily a device provided with a liquid pressure assistance means in which a change against a liquid pressure brake device provided with a master cylinder and a negative pressure booster is inhibited to the minimum without requiring a complex piping. SOLUTION: This hydraulic brake device for vehicle is provided with a negative pressure booster VB, a liquid pressure booster HB, and a valve mechanism VM for controlling an assistance by the liquid pressure booster HB. The negative pressure booster VB and a master cylinder MC are connected through an intermediate member MD and at least the liquid pressure booster HB and the valve mechanism VM is integrally constituted on the intermediate member. A motor M, a liquid pressure pump HP, a one directional valve CH, a relief valve RL and a solenoid valve device PV are integrally constituted on the intermediate member MD. Thereby, they are auxiliarily provided as a unit body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic brake system for a vehicle, comprising a negative pressure boosting means and a hydraulic pressure boosting means as a boosting means for driving a master cylinder in response to a brake pedal operation. The present invention relates to a hydraulic brake device having a valve mechanism for controlling assist by means and capable of performing various types of braking control.

[0002]

2. Description of the Related Art A hydraulic brake system having a negative pressure assisting means and a hydraulic assisting means is disclosed, for example, in Japanese Patent Laid-Open No. 52-496.
In Japanese Patent Application Publication No. 9-2006, there is proposed a vehicle brake booster in which the boosting ratio of the booster can be increased by combining a vacuum booster (negative pressure assisting means) and a hydraulic booster (hydraulic pressure assisting means).
The hydraulic booster provided for this uses the discharge brake hydraulic pressure of a power steering pump.

In the specification of US Pat. No. 3,976,536, there is disclosed a pneumatic power brake device (negative pressure assisting means) and a hydraulic power brake device (hydraulic pressure) utilizing a discharge brake hydraulic pressure of a power steering pump. It has been proposed to use an auxiliary hydraulic pressure source in a brake device having assisting means) to cope with a case such as when the engine is stopped. Specifically, an electric pump is provided as an auxiliary hydraulic pressure source, a pressure responsive switch is arranged between the pump and the power steering gear, and the electric pump is driven by the pressure responsive switch.

On the other hand, with respect to a brake fluid pressure generating device having a fluid pressure assisting means, a linear solenoid valve is interposed in an output side fluid pressure passage of an electric pump as an auxiliary fluid pressure source so that automatic operation of a brake can be performed. An apparatus has been proposed. For example, German Patent No. 197070376A1 discloses a master cylinder, a hydraulic booster mechanism having a booster piston, a motor-driven pump, and a pressure control valve for controlling boosted hydraulic pressure applied to the booster piston. There is disclosed a brake fluid pressure generating device which is configured to control the pressure control valve by a proportioning solenoid to perform traction control and stability control.

[0005]

SUMMARY OF THE INVENTION The aforementioned U.S. Pat.
In the apparatus described in Japanese Patent No. 67536, the discharge brake fluid pressure of a power steering pump or an electric pump is used for assisting the fluid pressure. However, since it is connected via a communication pipe, complicated piping is required. No consideration has been given to manufacturing problems and vehicle mountability.
According to the device described in German Patent No. 197070376A1, traction control and stability control can be performed by controlling the pressure control valve with a proportioning solenoid. Only means and no negative pressure assisting means are provided.

[0006] Further, in the apparatus described in the above-mentioned Japanese Patent Application Laid-Open No. 52-4969 and US Pat. No. 3,976,536, the valve mechanism is formed in a negative pressure booster, and the conventional master cylinder and / or Significant improvements are required for negative pressure boosters. For this reason, when manufacturing a hydraulic brake device having both a negative pressure booster and a hydraulic pressure booster, the system is different from that of the conventional hydraulic brake device having a master cylinder and a negative pressure booster. Therefore, it is necessary to set a hydraulic brake device having a completely different specification according to the type of vehicle. Also, different specifications may be set for the same vehicle type. In this case, it is necessary to prepare two completely different types of devices, a conventional hydraulic brake device and a dedicated hydraulic brake device.

[0007] Further, for example, a member provided with a hydraulic pressure urging means and a valve mechanism for controlling the hydraulic pressure urging is added to the conventional hydraulic brake device having a master cylinder and a negative pressure booster. If it is possible, it is possible to easily cope with various specifications, and it is possible to reduce costs by facilitating manufacturing and assembly.

In view of the above, the present invention provides a valve mechanism which includes a negative pressure assisting means and a hydraulic assisting means as assisting means for driving a master cylinder in response to a brake pedal operation, and controls the assisting by the hydraulic assisting means. In the hydraulic brake system of a vehicle equipped with, minimizing changes to the conventional hydraulic brake system with a master cylinder and a negative pressure booster, and easily manufacturing and assembling without requiring complicated piping It is an object of the present invention to provide a hydraulic brake device capable of performing the following.

Another object of the present invention is to provide a hydraulic brake device having a conventional master cylinder and a negative pressure booster so that hydraulic assisting means and the like can be easily provided.

[0010]

In order to solve the above-mentioned problems, the present invention, as described in claim 1, drives a master cylinder piston forward in response to operation of a brake pedal,
A master cylinder that boosts the brake fluid in the reservoir and outputs the brake fluid pressure, negative pressure assisting means that assists the master cylinder piston with a negative pressure according to the operation of the brake pedal, and is independent of the master cylinder. Pump means for increasing the brake fluid in the reservoir to output brake fluid pressure; and a power chamber formed behind the master cylinder piston, wherein the output fluid pressure of the pump means is increased in response to operation of the brake pedal. A hydraulic pressure assisting device for assisting the master cylinder piston by supplying to the chamber and a valve mechanism for controlling the assisting of the master cylinder piston by the hydraulic pressure assisting device; Means and said master cylinder are connected via an intermediate member, at least said hydraulic pressure assisting means and said valve are connected to said intermediate member. In which it was decided to construct integrally with the structure.

Preferably, the pump means is integrally formed with the intermediate member. For example,
If the pump means is disposed vertically in front of the negative pressure booster, the dead space between the conventional negative pressure booster and the reservoir can be effectively used.
The valve mechanism may be constituted by, for example, a valve seat formed at a front end of a power piston constituting the hydraulic pressure assisting means, and a valve body supported at a rear end of the master cylinder piston.

Further, as set forth in claim 3, there is provided a one-way valve which is connected to the output side of the pump means and permits a flow to the power chamber and prohibits a flow in the reverse direction. A directional valve may be provided in the intermediate member.

According to a fourth aspect of the present invention, there is provided a solenoid valve device having an input side connected to the discharge side of the hydraulic pressure assisting means and an output side connected to the reservoir. A valve device may be provided in the intermediate member. The solenoid valve device is interposed between the discharge side of the hydraulic pressure assisting means and the reservoir, and restricts a flow rate of the pressure reducing hydraulic passage according to an operation state of the brake pedal and / or a vehicle state. It is preferable to provide a linear solenoid valve that performs the operation.

Further, as set forth in claim 5, a hydraulic passage connecting the power chamber side of the one-way valve to an input side of the solenoid valve device is formed in the intermediate member, A relief valve interposed in the hydraulic pressure path, which is normally closed and communicates when the output hydraulic pressure of the pump means exceeds a predetermined pressure may be provided in the intermediate member.

According to a sixth aspect of the present invention, the negative pressure booster, the intermediate member, and the master cylinder are
The connection can be made by fastening with at least one bolt penetrating the negative pressure booster and the intermediate member.

It is to be noted that a pedal operation amount sensor for detecting an operation amount of the brake pedal is provided, and a detection output of the pedal operation amount sensor is compared with a predetermined operation amount. It is preferable that the pump unit is stopped and the pump unit is driven when a predetermined operation amount is exceeded. Alternatively, a pressure sensor for detecting the pressure in the variable pressure chamber of the negative pressure assisting means is provided, and the detection output of the pressure sensor is compared with a predetermined pressure, and when the pressure is below a predetermined pressure, the pump means is stopped. , The pump means may be driven when a predetermined pressure is exceeded. The predetermined operation amount and the predetermined pressure may be set to values immediately before the negative pressure assisting unit reaches the assisting limit.

[0017]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. First, an outline of an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the hydraulic brake device of the present embodiment has a master cylinder MC, a negative pressure booster VB and a hydraulic pressure booster HB, and the master cylinder piston MP is driven forward in response to the operation of the brake pedal BP. The brake fluid introduced from the reservoir RV is compressed, and the brake fluid pressure is output from the pressure chambers R1 and R2. The negative pressure booster VB and the hydraulic pressure booster HB assist the operation of the master cylinder piston MP in response to the operation of the brake pedal BP, and constitute the negative pressure assisting means and the hydraulic pressure assisting means of the present invention, respectively. The hydraulic booster HB of the present embodiment is formed integrally with the intermediate member MD,
Has a form interposed between the master cylinder MC and the negative pressure booster VB as a unit body. The output brake fluid pressure of the master cylinder MC is supplied to a wheel cylinder (not shown) mounted on each wheel of the vehicle.

The negative pressure booster VB is a housing HS which forms a constant pressure chamber CP and a variable pressure chamber VP via a movable wall MW.
And a driving member AM supported by the pressure chamber CP.
Is connected to a negative pressure source such as an intake manifold (not shown). The drive member AM is movably supported with the movable wall MW with respect to the housing HS, and communicates with the variable pressure chamber VP and the atmosphere in response to the operation of the brake pedal BP, and the variable pressure chamber V
And a control valve mechanism CV for controlling the communication between the pressure control chamber CP and the constant pressure chamber CP. The MP is configured to be boosted.

In this embodiment, the master cylinder piston MP is provided in the intermediate member MD interposed as a unit between the negative pressure booster VB and the master cylinder piston MC.
A power piston PP is disposed so as to contact the rear end of the power piston PP. And these master cylinder pistons MP
A valve mechanism VM that controls hydraulic pressure assist is formed between the power piston PP and the power piston PP. Note that a reaction force elastic member RD is interposed between the transmission member TM and the drive member AM.

Further, in the intermediate member MD configured as a unit body as described above, FIG.
The members and devices shown in the dashed-line frame are accommodated below. That is, as the pump means of the present invention, the hydraulic pump HP driven by the electric motor M is an intermediate member MD.
The brake fluid pressure is output independently of the master cylinder MC. The hydraulic pump HP has an input side connected to the reservoir RV, and an output side connected to a power chamber RP behind the power piston PP via a one-way valve CH. The output of the hydraulic pump HP is connected to the power chamber RP. When hydraulic pressure (power hydraulic pressure) is supplied, power piston PP
Is driven forward, and the master cylinder piston MP is assisted.

In the intermediate member MD, as shown in FIG. 1, the output side of the hydraulic pump HP is connected to the power chamber RP via the pressure-increasing-side hydraulic pressure path AI. A one-way valve CH is interposed in the pressure line AI. At the same time, the power chamber RP is provided with the valve mechanism VM and the pressure reducing hydraulic passage AO.
Is connected to the reservoir RV via the. And
A solenoid valve device PV is interposed in the pressure-reducing hydraulic passage AO, and constitutes a flow restricting means for restricting the flow rate of the pressure-reducing hydraulic passage AO according to the operation state of the brake pedal BP and / or the vehicle state. ing. Further, a hydraulic passage AC is formed in the intermediate member MD to connect the power chamber RP side of the one-way valve CH to the input side of the solenoid valve device PV, and the hydraulic passage AC is normally closed. And a relief valve R which communicates when the output hydraulic pressure of the hydraulic pump HP exceeds a predetermined pressure.
L is interposed. Incidentally, the solenoid valve device PV of the present embodiment is a linear solenoid valve, that is, a proportional control valve,
The pressure difference before and after the change is controlled so as to change in proportion to the solenoid drive current.

In the present embodiment, as a first detecting means for detecting the operation state of the negative pressure booster VB, the variable pressure chamber V
A pressure sensor DT1 for detecting the pressure in P is provided, and an output signal thereof is supplied to the electronic control unit ECU. Alternatively or together with this, as a second detecting means for detecting the operation amount of the brake pedal BP, as shown by a broken line in FIG.
A stroke sensor DT2 for detecting the stroke of P may be provided, and an output signal thereof may be supplied to the electronic control unit ECU.

The electronic control unit ECU includes a brake switch (not shown) which is turned on when the brake pedal BP is depressed, a wheel speed sensor (not shown) as a vehicle state detecting means, An acceleration sensor YG, a hydraulic pressure sensor PS, and the like are connected, and these output signals are configured to be input to the electronic control unit ECU. The electronic control unit ECU of the present embodiment is a microcomputer including a CPU (not shown), a ROM, a RAM (not shown), an input port, an output port (not shown), and the like, which are interconnected via a bus. The output signals of the above-described sensors and the like are configured to be input to the CPU from input ports via an amplifier circuit (not shown).

When the brake pedal BP is operated, the negative pressure booster VB is operated, the transmission member TM moves forward, and the master cylinder piston MP is assisted (negative pressure assist). When the brake fluid pressure in the master cylinder MC rises and exceeds a predetermined pressure, the power chamber RP is closed by the valve mechanism VM. Then, in the electronic control unit ECU, for example, the pressure sensor DT1 and the stroke sensor DT
If it is determined that at least one of the detection outputs of the second pump has exceeded a predetermined reference value, the electric motor M is driven and the hydraulic pump H
The output hydraulic pressure of P is supplied to the power chamber RP, and the master cylinder piston MP is assisted (hydraulic assist).

The solenoid valve device PV is controlled by the electronic control unit ECU so that the differential pressure before and after the brake pedal BP changes in proportion to the solenoid drive current in accordance with the operation state of the brake pedal BP and / or the vehicle state. Is done. Thus, the operation state of the brake pedal BP and / or the vehicle state is determined based on the detection output of each of the above sensors, and the solenoid valve device PV is appropriately controlled in accordance with these states, and the pressure-reducing hydraulic pressure path AO Is limited, and various types of braking control such as traction control, braking steering control, and brake assist control are performed.

Here, the drive start determination of the hydraulic pump HP will be described. First, the pressure (Pv) in the variable pressure chamber VP detected by the pressure sensor DT1 is equal to the predetermined pressure K.
The electric motor M is started when it is larger than p, and the brake hydraulic pressure is output from the hydraulic pump HP.
In other words, power is not supplied to the electric motor M until the pressure Pv (negative pressure) in the transformation chamber VP reaches the predetermined pressure Kp.
Therefore, the hydraulic pump HP is in a stopped state. Predetermined pressure Kp
Is set based on the assist limit of the negative pressure booster VB. In order to ensure a smooth transition when the assist of the hydraulic booster HB is added by the hydraulic pump HP, the pressure in the variable pressure chamber VP must be equal to the atmospheric pressure. (That is, immediately before the negative pressure booster VB reaches the assisting limit).

Further, the pressure Pv in the transformation chamber VP is differentiated,
The change amount DPv of the pressure Pv may be obtained, and the change amount DPv may be compared with a predetermined value Kdp. In this case, the predetermined value Kdp is also set to the pressure change amount immediately before the negative pressure booster VB reaches the assisting limit. Is desirable. Then, as a determination condition, the comparison result of the above-described pressure Pv and the predetermined pressure Kp may be combined, and the electric motor M may be started when both conditions are satisfied. Further, in addition to these conditions, the output of an existing brake switch (not shown) for detecting that the brake pedal BP has been operated is added, the brake switch is turned on, and the pressure P
The electric motor M may be configured to be activated when v and / or the change amount DPv exceeds a predetermined pressure Kp and / or a predetermined value Kdp.

Alternatively, a stroke sensor DT2 indicated by a broken line in FIG. 1 is used as a means for detecting the operation amount of the brake pedal BP, and the stroke (St) of the brake pedal BP, which is the detection output, is determined by a predetermined stroke KS.
The configuration may be such that the electric motor M is activated when it becomes larger than the value t. Even in this case,
The predetermined stroke KSt is desirably set to a value immediately before the negative pressure booster VB reaches the assist limit in order to ensure a smooth transition when the assist by the hydraulic pressure booster HB is added. Further, the stroke St is differentiated, and the change amount D is obtained.
St may be obtained and compared with a predetermined value Kds. In this case, it is preferable that the predetermined value Kds is also set to the stroke change amount immediately before the negative pressure booster VB reaches the assisting limit. Further, the configuration may be such that the electric motor M is started when both the conditions of the stroke St and the change amount DSt are satisfied.

As means for detecting the operation amount of the brake pedal BP, a pedaling force sensor (not shown) for detecting a pedaling force on the brake pedal BP, and a master cylinder MC
Pressure sensor (not shown) for detecting output brake fluid pressure
The driving start of the hydraulic pump HP can also be determined using the pedaling force or the master cylinder hydraulic pressure, which are the detection results, and / or their differential values. Further, a vehicle speed sensor (not shown) may be provided to drive and control the electric motor M according to the output signal thereof, and control the operation of the hydraulic pump HP according to the vehicle speed.

According to the hydraulic brake device of the present embodiment having the above configuration, the input / output characteristics shown in FIG. 2 can be obtained according to the operation of the brake pedal BP. FIG. 2 shows FIG.
(Depressing force on brake pedal 2) and output (output brake fluid pressure of master cylinder MC) in the embodiment of FIG.
The solid line indicates the assisting operation by the negative pressure booster VB, the broken line indicates the assisting limit of the negative pressure booster VB, and the two-dot chain line indicates the hydraulic booster HB in addition to the assisting by the negative pressure booster VB. , And the dashed line shows the characteristics when the negative pressure booster VB fails. In addition, according to the hydraulic brake device of the present embodiment, the braking force on each wheel can be controlled independently of the operation of the brake pedal BP, and, for example, braking steering control can be performed to ensure stable running of the vehicle. .

First, during normal brake operation,
When the brake pedal BP is operated, the state shown in FIG. 1 at the time of non-operation is changed to the state shown in FIG. The characteristic shown by the solid line in FIG. Further, when the brake pedal BP is operated and the master cylinder hydraulic pressure exceeds a predetermined pressure, the valve mechanism VM is closed as shown in FIG. Then, when the pressure Pv in the variable pressure chamber VP detected by the pressure sensor DT1 becomes larger than the predetermined pressure Kp, the electric motor M is started, and the discharge brake fluid of the hydraulic pump HP flows into the power chamber RP behind the power piston PP. The power piston PP is supplied and driven forward. In this case,
When the output hydraulic pressure of the hydraulic pump HP exceeds the predetermined pressure of the relief valve RL, the relief valve RL opens and communicates, so that the upper limit of the power hydraulic pressure in the power chamber RP, that is, the maximum pressure during the hydraulic pressure assist is Is set.

Thus, in addition to the assistance by the negative pressure booster VB, the assistance by the hydraulic pressure booster HB is performed.
The characteristic shown by the dotted line is obtained. Further, when the negative pressure booster VB fails, the characteristic shown by the one-dot chain line in FIG. 2 is obtained. Further, at the time of various types of braking control, after an ignition switch (not shown) is closed, a series of processes such as braking steering control and brake assist control are performed by the electronic control unit ECU. Omitted.

Next, an embodiment showing a specific configuration of the present invention will be described with reference to FIGS. The hydraulic brake device according to the embodiment of FIG. 5 includes a master cylinder 10, an intermediate member 20, and a negative pressure booster 40 corresponding to the master cylinder MC, the intermediate member MD, and the negative pressure booster VB of FIG.
Are connected. The intermediate member 20 includes the above-described valve mechanism VM.
And a hydraulic booster HB. The electric motor M, the hydraulic pump HP, the one-way valve CH, the relief valve RL, the solenoid valve device PV, and the hydraulic paths AO, AI, AC and the like are all stored in the intermediate member 20. The one-way valve CH, the relief valve RL, and the solenoid valve device PV are indicated by symbols in FIG.
And FIG. 9, which will be described later. The configuration of the electronic control unit ECU and the like is the same as that of the embodiment of FIG. 1, and the same components are denoted by the same reference numerals.

As shown in FIG. 5, the master cylinder 10 disposed on the front side of the vehicle (left side in FIG. 5) and the negative pressure booster 40 disposed on the rear side of the vehicle (right side in FIG. And a negative pressure booster 4
0, a brake pedal BP (omitted in FIG. 5) is provided. The depressing force applied to the brake pedal BP is transmitted as a brake operating force via the input rod 3, and is assisted by the negative pressure booster 40 in response thereto.
When the negative pressure booster 40 is near the assisting limit, the hydraulic pressure booster HB further assists and the master cylinder 10 outputs the brake hydraulic pressure. The output brake fluid pressure of the master cylinder 10 is supplied to a wheel cylinder (not shown) mounted on each wheel of the vehicle.

The master cylinder 10 and the intermediate member 20 are
It is configured as shown in FIG. First, the first cylinder 1a accommodates a part of the second cylinder 1b and the third cylinder 1c, and the first piston 11 and the second piston 12 are accommodated in these cylinders. Is configured. The first cylinder 1a is a bottomed cylindrical body, and is formed with a stepped hole so that the inner diameter increases gradually toward the opening. The second cylinder 1b is a substantially cylindrical body having a cylinder bore 1d, and the third cylinder 1c is a substantially cylindrical body having a stepped inner hole.
A cylinder bore 1e having an inner diameter larger than the inner diameter of d is formed, and a communication hole 1f having a diameter smaller than the inner diameter of the cylinder bore 1d is formed therein. Also, the first cylinder 1
a is a liquid supply port 1g, 1h and an output port 1j, 1k.
Are formed, and an input port 1p and a discharge port 1r are formed in the third cylinder 1c.

The second cylinder 1b has a communication hole 1 in the radial direction.
It is housed in the first cylinder 1a via an annular member 17 formed with 7a and cup-shaped seal members (represented by S1) disposed on both sides thereof. The third cylinder 1c is housed in the first cylinder 1a via an annular member 18 having a communication hole 18a formed in the radial direction and a seal member S1 and an annular member 1x disposed on both sides. .

A first piston 11 of a bottomed cylindrical body is slidably housed in the cylinder bore 1d in a liquid-tight manner, and a pressure chamber R1 is formed between the first cylinder 1a and the first piston 11. Have been. When the first piston 11 is not operated, the communication hole 11 a formed in the skirt portion thereof is
The pressure chamber R1 is configured to communicate with the reservoir 4 via the liquid supply port 1g.

The second piston 12 has concave portions 12b and 12c formed at both ends thereof, and has a large diameter portion 12e formed by expanding its rear end. Second piston 1
The front end of 2 is slidably housed in the cylinder bore 1d in a liquid-tight manner, and a pressure chamber R2 is defined between the first piston 11 and the second piston 12 in the cylinder bore 1d. When the second piston 12 is not actuated, the communication hole 12a formed in the skirt portion thereof is connected to the communication hole 1 of the annular member 18.
The pressure chamber R <b> 2 is configured to communicate with the reservoir 4 via the liquid supply port 1 h.

A rubber disc 25 is accommodated in the concave portion 12c behind the second piston 12, and a support member 22 is accommodated via an annular spacer 26.
A communication hole 22a is formed in the center of the support member 22 in the axial direction. A valve body 23 is slidably supported in the communication hole 22a, and a base end thereof is disposed so as to contact the rubber disk 25. Have been. A liquid chamber R3 is defined between the outer peripheral surface of the second piston 12 and the inner peripheral surface of the cylinder bore 1e, and the liquid chamber R3 is configured to always communicate with the discharge port 1r. Large-diameter portion 12 of second piston 12
On the front side of e, a communication hole 12f is formed in the radial direction, and the opening of the concave portion 12c communicates with the liquid chamber R3.

In FIG. 6, a spring 13 is stretched between the bottom of the recess in the first cylinder 1a and the bottom of the recess of the first piston 11 so that the first piston 11 moves in the direction of the second piston 12. Being energized. Further, one end of a rod 14 is fixed to the bottom surface of the concave portion 12b in front of the second piston 12, and the distal end of the retainer 16 is disposed on the head at the other end so as to be locked. The retainer 16 is disposed such that the bottom thereof abuts the rear end surface of the first piston 11, and the bottom of the retainer 16 and the second piston 1
A spring 15 is stretched between the bottom of the recess 12b and the front of the second piston 12 and is urged in a direction in which the space between the first piston 11 and the second piston 12 expands.

An intermediate member 20 is interposed between the first cylinder 1a constituting the master cylinder 10 and the negative pressure booster 40, and as shown in FIG.
Are joined by The intermediate member 20 incorporates various components and devices, including a hydraulic booster HB, around the body of a third cylinder 1c whose tip is housed in the first cylinder 1a. Intermediate member 2 shown in FIG.
0 indicates a state in which the arm portion 20a is extended and formed,
FIG. 6 shows a cross section of a portion different from FIG. 5 above the third cylinder 1c in FIG. In addition, the arm part 20a
Due to the arrangement of each member, the hydraulic passage is formed integrally so as to connect the hydraulic passage in the intermediate member 20 to the reservoir 4.

The large diameter portion 21d of the power piston 21 is slidably supported in the cylinder bore 1e of the third cylinder 1c. A small-diameter portion of the power piston 21 is slidably supported in the communication hole 1f formed in the third cylinder 1c. Thus, a power chamber RP is formed between the rear end face of the large diameter portion 21d of the power piston 21 and the step of the third cylinder 1c, and the input port 1p is configured to communicate with the power chamber RP. ing. A cup-shaped sealing member S2 is provided at the rear end of the large-diameter portion 21d of the power piston 21 to ensure the sealing performance with respect to the power chamber RP. In addition, an annular groove is formed on the inner surface of the communication hole 1f of the third cylinder 1c, and an annular groove is also formed on the inner surface separated from the inner surface by a predetermined distance in the axial direction. A cup-shaped seal member (typically represented by S3) is housed therein, and the sealing performance with respect to the power chamber RP is ensured.

Further, concave portions are formed at the front and rear ends of the power piston 21 so that the large-diameter portion 21 of the power piston 21 is formed.
d, a valve seat 21a is formed in the center of a concave portion formed on the front side, and an axial communication hole 21 opening in the valve seat 21a.
b and a radial communication hole 21c communicating therewith and opening to the power chamber RP. At the rear end of the power piston 21, the plunger 31a at the tip of the transmission member 31 is disposed so as to contact the bottom surface of the concave portion 21e.

In the communication hole 21b of the power piston 21,
A spring 24 for urging the valve body 23 in a direction away from the valve seat 21a is provided, and a gap is always formed between the tip of the valve body 23 and the valve seat 21a. As described above, when the distal end of the valve body 23 is separated from the valve seat 21a, the power chamber RP communicates with the liquid chamber R3 via the communication holes 21b and 21c of the power piston 21.

Next, the negative pressure booster 40 is shown in FIGS.
As shown in FIG. 1, a container-like housing 4 called a shell
1a and 41b are overlapped via the movable wall 42, a constant pressure chamber (negative pressure chamber) CP is formed in the front, and a variable pressure chamber VP is formed in the rear. The constant pressure chamber CP is connected to a negative pressure source such as an intake manifold (not shown) via an inlet (not shown), and maintains a negative pressure. The movable wall 42 is composed of a pressure receiving plate 42a and a diaphragm 42b, and has a cylindrical driving member 4
3 is hermetically fixed at one open end, and the driving member 43
The other open end portion extends rearward through the housing 41b. The drive member 43 is slidably supported by the opening of the housing 41b via a seal member S4, and is further surrounded by a boot BT. Although the boot BT is fixed to the input rod 3, a communication hole BTa is formed at the opening end of the driving member 43. The front end of the drive member 43 and the front housing 41a
A spring 44 is disposed between the movable wall 4 and the inner surface of the movable wall 4.
2 is urged toward the rear housing 41b.

The input rod 3 is arranged so as to be located on the central axis in the driving member 43, and the tip thereof is connected to a plunger 45 via a ball joint. This plunger 45
Is an axial communication hole 43a formed in the driving member 43.
Slidably supported by A valve seat 43b is formed around the communication hole 43a, and a first control valve mechanism 46 that urges an annular valve body 46a so as to abut the opening end surface of the valve seat 43b is provided with a driving member 43. Is configured within. The first control valve mechanism 46 is called a control valve. Further, a valve seat 45b is formed at the rear end of the plunger 45, and an annular valve body 47a is urged so as to contact the valve seat 45b. A second control valve mechanism 47 is connected. The second control valve mechanism 47 is called an air valve, and is provided with a valve body 4 at the front end of a cylindrical elastic member.
7a is formed and arranged so as to be urged toward the valve seat 43b by a spring 48a supported at the rear end.
The rear end of the elastic member constituting the second control valve mechanism 47 is also arranged so as to be urged in the direction of the valve seat 43b by a spring 48b, and a step 43c formed inside the drive member 43 by this urging force. It is locked to.

An annular reduced diameter portion 45a is formed behind the sliding portion formed at the tip of the plunger 45, and a key member is provided so as to be able to move a predetermined distance in the axial direction with respect to the reduced diameter portion 45a. 49 are fitted. The key member 49 protrudes from the outer periphery of the driving member 43 and is arranged so as to engage with the housing 41b so as to restrict the axial movement of the plunger 45 rearward, whereby the return position of the movable wall 42 is defined. .

A recess 43d is formed in front of the driving member 43, and the transmission member 32 is slidably fitted therein. The rear end portion 31b of the transmission member 31 is enlarged in diameter to form a bottomed cylindrical body.
Are accommodated and arranged coaxially with the transmission member 32 and the plunger 45. The transmission member 32 is supported movably in the axial direction by a predetermined distance, and is disposed so as to abut on the reaction rubber disc 33. The reaction rubber disc 33 is substantially the same as the reaction elastic member RD in the embodiment of FIG.

In this embodiment, as shown in FIG. 5, an electric motor M and a hydraulic pump HP driven by the electric motor M are also provided on the intermediate member 20, and the hydraulic pump HP has a reservoir on the input side. 4 and the output side is connected to the power chamber RP via the one-way valve CH.
As described above, since the hydraulic pump HP is connected to the power chamber RP via the one-way valve CH, even when the hydraulic pump HP is stopped, the brake fluid is supplied from the power chamber RP to the hydraulic pump HP. It does not flow out to the side, so that smooth operation can be maintained.

The drive start determination of the hydraulic pump HP is performed based on the detection output of the pressure sensor DT1 for detecting the pressure in the variable pressure chamber VP of the negative pressure booster 40 as described above.
In addition, instead of or together with the pressure sensor DT1,
A pedal operation amount sensor or the like for detecting the operation amount of the brake pedal BP is provided, and the hydraulic pump H
The determination of the start of driving of P may be performed. Thus,
When the negative pressure booster 40 comes to just before the assist limit, the second piston 12 is further assisted by the output hydraulic pressure of the hydraulic pump HP, as described later.

FIG. 8 shows the structure of a relief valve RL provided in the intermediate member 20. A valve seat 201 provided on the input side of the relief valve RL and a spring 203 in a direction for closing the valve seat 201 are shown.
The input side is connected to the output side of the hydraulic pump HP, and the output side is connected to the reservoir 4 (actually, the solenoid valve device PV and the discharge port 1).
r). Therefore, the valve body 202 is normally moved by the urging force of the spring 203 so that the valve seat 201 is closed.
When the discharge brake fluid pressure of the hydraulic pump HP exceeds a predetermined pressure, the valve body 202 separates from the valve seat 201 and the discharge brake fluid of the hydraulic pump HP passes through the solenoid valve device PV in the open position. And returned to reservoir 4. Thus, the upper limit of the power hydraulic pressure in the power chamber RP is set.

FIG. 9 shows a structure of a solenoid valve device PV provided in the intermediate member 20. The solenoid valve device PV is provided at the input side thereof, and is provided at the tip of a plunger 207. The valve body 205 is biased in a direction to open the valve body 205, and its input side is connected to the discharge port 1r, and its output side is connected to the reservoir 4. In the solenoid valve device PV, the plunger 207 is driven in accordance with the energization of the solenoid coil 208, and a valve body 205 provided at the tip of the plunger 207 sits on or separates from the valve seat 204, and the drive current to the solenoid coil 208 Is controlled so that the differential pressure across the valve element 205 changes in proportion to. 8 and 9 indicate the flow of the brake fluid.

Next, the overall operation of the hydraulic brake device having the above configuration will be described. First, when the brake pedal BP is in the non-operating state, each component is in the state shown in FIGS. Accordingly, the negative pressure booster 40 is in a non-operating state, the second control valve mechanism 47 is in a closed state with the valve body 47a abutting against the valve seat 45b, and the air is introduced into the variable pressure chamber VP. Has been blocked. At this time, only the negative pressure in the constant pressure chamber CP is acting on the first control valve mechanism 46.

When the brake pedal BP is operated and an operating force is applied to the input rod 3, the valve body 47a of the second control valve mechanism 47 of the negative pressure booster 40 separates from the valve seat 45b,
If the sum of the operating force on the input rod 3 and the force for urging the input rod 3 forward by the pressure difference between the pressure in the variable pressure chamber VP and the pressure in the constant pressure chamber CP exceeds the urging force of the spring 48b, The input rod 3 and the plunger 45 move forward,
A first control valve mechanism 46 is provided for the valve seat 43b of the drive member 43.
Of the variable pressure chamber VP and the constant pressure chamber CP are cut off. Then, the valve body 47a of the second control valve mechanism 47 separates from the valve seat 45b, and the communication hole B of the boot BT.
The atmosphere is introduced into the transformation chamber VP through Ta, and the transformation chamber V
The pressure in P increases. As a result, a force for pressing the movable wall 42 forward is generated, and the second force is applied via the driving member 43, the reaction rubber disc 33, the transmission member 31, the power piston 21, the support member 22, the spacer 26, and the rubber disc 25.
Is driven forward, and the first piston 11 is further driven forward.

When assisted by the negative pressure booster 40,
When the master cylinder fluid pressure rises due to the pressure rise in the pressure chambers R1 and R2, the reaction rubber disc 33 is
Is bulged rearward and abuts against the distal end surface of the transmission member 32, and a rearward reactive force proportional to the pressing force of the movable wall 42 is applied to the transmission member 32 and the plunger 45, and this reaction The first control valve mechanism 46 and the second control valve mechanism 47 are controlled according to the difference between the force and the operating force applied to the input rod 3.

When the pressure in the pressure chambers R1 and R2 further rises and becomes equal to or higher than a predetermined pressure, the rubber disk 25 is compressed, swells rearward through a hole in the center of the spacer 26, and is driven rearward. As a result, the valve body 23 moves rearward against the urging force of the spring 24, and the valve seat 21 of the power piston 21 is moved.
When seated at a, the communication between the power chamber RP and the liquid chamber R3 is cut off. Then, when it is determined based on the output signal of the pressure sensor DT1 that the negative pressure booster 40 is immediately before the assist limit, the electric motor M is started and the hydraulic pump HP is driven. Specifically, for example, when the pressure Pv in the variable pressure chamber VP detected by the pressure sensor DT1 becomes larger than a predetermined pressure Kp, the electric motor M is started, and the output hydraulic pressure of the hydraulic pump HP changes the input port 1p. It is configured to be supplied to the power chamber RP through the power chamber RP.

When the negative pressure booster 40 comes to just before the assist limit, the output hydraulic pressure of the hydraulic pump HP, that is, the power hydraulic pressure is applied to the rear end face of the large diameter portion 21d of the power piston 21, and the second The piston 12 is pressed forward, and the assistance by the hydraulic booster HB is added. At this time, the communication hole 1f
The power hydraulic pressure of the cross section of the power piston 21 is transmitted to the rear input rod 3 as a reaction force of the hydraulic booster HB.

As described above, in the present embodiment, the hydraulic booster HB and the valve mechanism VM are integrally formed in the intermediate members MD and 20, and the hydraulic pressure booster HB and the valve booster VM are integrated without changing the conventional negative pressure booster. Since a device including the booster HB and the valve mechanism VM can be configured, an inexpensive device can be provided. In particular, since a hydraulic path may be formed in the intermediate members MD, 20, it is not necessary to newly form a hydraulic path in the master cylinders MC, 10. Therefore, by adding the intermediate members MD and 20 as a unit to the conventional hydraulic brake device of the master cylinder and the negative pressure booster, a hydraulic pressure assisting means and a valve mechanism for controlling the hydraulic pressure assist can be easily added. be able to.

Further, by providing the electric motor M and the hydraulic pump HP integrally with the intermediate member MD, 20, these mounts, brackets and the like become unnecessary, and piping by pipes becomes unnecessary. As a result, not only can the cost be reduced, but also good reliability can be obtained. Further, if the electric motor M and the hydraulic pump HP are arranged vertically in front of the negative pressure booster 40 as shown in FIGS. 5, 10 and 11, the conventional dead space can be effectively used. be able to.

In particular, in this embodiment, the electric motor M, the hydraulic pump HP, the one-way valve CH, the relief valve RL,
Since the solenoid valve device PV and all of the hydraulic passages AO, AI, AC, etc. connecting them are accommodated in the intermediate member 20, for example, not only the specifications of the hydraulic pressure assisting means and the valve mechanism but also the hydraulic pressure Even if the control characteristics are different, the intermediate member 20
Can be set to desired specifications and desired characteristics simply by replacing

When the brake is activated, the electric motor M
In addition, the operating frequency of the hydraulic pump HP can be minimized, and the hydraulic pump HP is started before the negative pressure booster 40 reaches the assisting limit, so that the hydraulic pressure can be smoothly increased with good responsiveness. The assistance by the booster HB can be added. Further, by monitoring the detection output of the pressure sensor DT1, it is possible to detect an absolute pressure shortage of the negative pressure source connected to the negative pressure booster 40. In this case, the hydraulic pressure booster H
Since the necessary braking force can be ensured by the assistance of B, it is also effective in securing a so-called partial braking force.

Further, according to each embodiment of the present invention including FIG. 1 described above, not only the brake assist control but also the automatic brake control can be applied, whereby the inter-vehicle distance is automatically controlled. be able to. In addition to the control of the solenoid valve device PV, the brake assist control can be performed by, for example, controlling the duty of the motor M and controlling the output of the hydraulic pump HP.

FIG. 10 and FIG. 11 show another embodiment of the present invention. Although the assembling structure and the outer shape are slightly different, the internal structure is substantially the same as the above-described embodiment. In the present embodiment, the master cylinder 10x, the intermediate member 20x, and the negative pressure booster 40x can be integrally assembled with the two bolts BLx. That is, each of the bolts BLx penetrates the intermediate member 20x, one end extends to the master cylinder 10x side, the other end extends to the negative pressure booster 40x side, and furthermore, the vehicle body (not shown) is attached to the negative pressure booster 40x side end. ) Is formed.

Thus, according to this embodiment, the intermediate member 20x corresponding to various specifications can be easily assembled or replaced, and it is also necessary to separately provide a bolt for attaching to the vehicle body. Therefore, it can be easily and inexpensively mounted on a vehicle.

[0065]

The present invention has the following effects because it is configured as described above. That is, the invention according to claim 1 includes a negative pressure assisting unit and a hydraulic assisting unit, and further includes a valve mechanism that controls assisting by the hydraulic assisting unit,
The negative pressure assisting means and the master cylinder are connected via an intermediate member, and at least the hydraulic pressure assisting means and the valve mechanism are integrated with this intermediate member, so that the conventional master cylinder and negative pressure booster can be used. The change to the provided hydraulic brake device is minimized, and the manufacture and assembly can be easily performed without requiring complicated piping. In addition, an intermediate member integrally configured with a hydraulic pressure assisting unit and the like can be easily attached as a unit body to a conventional hydraulic brake device including a master cylinder and a negative pressure booster. .

In the hydraulic brake device according to the second to fifth aspects, the pump means, the one-way valve, the solenoid valve device, and the relief valve are appropriately disposed, respectively, so that complicated piping is not required and Can be manufactured and assembled. Further, an intermediate member including a pump means or the like can be easily attached as a unit body to a conventional hydraulic brake device including a master cylinder and a negative pressure booster.

Further, in the hydraulic brake device according to the sixth aspect, the negative pressure booster, the intermediate member, and the master cylinder can be easily connected, and the intermediate member corresponding to various specifications can be easily replaced. Can be. Further, since there is no need to separately provide a bolt for mounting to the vehicle body, the assembling property to the vehicle is excellent.

[Brief description of the drawings]

FIG. 1 is a sectional view of a hydraulic brake device according to an embodiment of the present invention.

FIG. 2 is a graph showing input / output characteristics according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a state in which assistance by a negative pressure booster is performed in one embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a state in which assistance is performed by a negative pressure booster and a hydraulic pressure booster in one embodiment of the present invention.

FIG. 5 is a sectional view showing a specific structure of a hydraulic brake device according to one embodiment of the present invention.

6 is an enlarged sectional view of a master cylinder and an intermediate member of the hydraulic brake device of FIG.

FIG. 7 is an enlarged sectional view of a negative pressure booster of the hydraulic brake device of FIG.

FIG. 8 is an enlarged sectional view of a relief valve of the hydraulic brake device of FIG.

FIG. 9 is an enlarged sectional view of a solenoid valve device of the hydraulic brake device of FIG. 5;

FIG. 10 is a side view of a hydraulic brake device according to another embodiment of the present invention.

FIG. 11 is a front view of a hydraulic brake device according to another embodiment of the present invention.

[Explanation of symbols]

BP brake pedal, RV, 4 reservoir, MC,
10 master cylinder, MD, 20 intermediate member, HB
Hydraulic booster, HP hydraulic pump, M electric motor, VM valve mechanism, PV solenoid valve device, VB,
40 negative pressure booster, AM driving means, CP constant pressure chamber, VP transformer chamber, TM, 31 transmission member,

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Taku Kurokawa 2-1-1 Asahi-cho, Kariya-shi, Aichi F-term (reference) in Aisin Seiki Co., Ltd. 3D048 BB21 BB54 CC11 CC26 CC39 GG03 GG22 HH15 HH26 HH66 HH67 RR06 RR11 RR25 RR35

Claims (6)

[Claims] 1. A master cylinder for driving a master cylinder piston forward in response to operation of a brake pedal to increase brake fluid in a reservoir to output brake fluid pressure, and a negative pressure in response to operation of the brake pedal. Negative pressure assisting means for assisting the master cylinder piston, pump means for increasing the brake fluid in the reservoir and outputting the brake fluid pressure independently of the master cylinder, and forming a power chamber behind the master cylinder piston A hydraulic pressure assisting means for supplying the output hydraulic pressure of the pump means to the power chamber in response to the operation of the brake pedal to assist the master cylinder piston; and assisting the master cylinder piston by the hydraulic pressure assisting means. A hydraulic brake device for a vehicle having a valve mechanism for controlling the pressure, wherein the negative pressure assisting means and the master cylinder A hydraulic brake device for a vehicle, wherein the hydraulic pressure assisting means and the valve mechanism are integrally formed with the intermediate member through an intermediate member. 2. A hydraulic brake system for a vehicle according to claim 1, wherein said pump means is formed integrally with said intermediate member. 3. A one-way valve connected to the output side of said pump means and permitting flow to said power chamber and prohibiting reverse flow is disposed in said intermediate member. 3. The hydraulic brake device for a vehicle according to 2. 4. A solenoid valve device having an input side connected to the discharge side of the hydraulic pressure assisting means and an output side connected to the reservoir is provided in the intermediate member. 4. The hydraulic brake device for a vehicle according to claim 3. 5. A hydraulic path for connecting and connecting the power chamber side of the one-way valve to an input side of the solenoid valve device is formed in the intermediate member, and is interposed in the hydraulic path, and is always connected. 5. A hydraulic brake system for a vehicle according to claim 4, wherein a relief valve which is closed and communicates when the output hydraulic pressure of said pump means exceeds a predetermined pressure is disposed in said intermediate member. 6. The negative pressure booster, the intermediate member and the master cylinder are connected by being fastened with at least one bolt penetrating the negative pressure booster and the intermediate member. A hydraulic brake device for a vehicle according to the above.