JPH0811709A - Brake liquid pressure controlling actuator for vehicle - Google Patents

Abstract

PURPOSE:To prevent the intrusion of water into an inside space through the aspiration action, by discharging the brake liquid which leaks into a hole in which a displacement type pump driving shaft is arranged, from a leaked-out brake liquid discharge hole, and allowing the inside space of an electromagnetic driving part cover and an electric motor housing to communicate to the outside air through the aspiration hole and a brake liquid discharge passage. CONSTITUTION:A leaked brake liquid discharge hole 125 for discharging the brake liquid which leaks inside a hole 105 because of the destruction of the liquidtight state of the slidable part of a pump plunger, outside a body 102, is formed on the undersurface of the body 102 from the lower part of the hole 105. The discharge hole 125 crosses with a through hole 116 which penetrates left and right through the body 102, and the hole diameter of the upper part from the hole 116 is made smaller than the hole diameter of the lower part from the hole 116. The lowest part of the inside space of a cover 113 is positioned slightly lower than the hole 116, and is allowed to communicate to the leaked brake liquid discharge hole 125 through an aspiration hole 128 in the horizontal direction formed on the body 102.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle brake fluid pressure control actuator.

[0002]

2. Description of the Related Art A vehicle brake fluid pressure control actuator inserted in a fluid pressure path from a brake master cylinder of a vehicle to a wheel brake, which is an electromagnetically operated fluid for controlling inflow and outflow of the brake fluid to and from the wheel brake. A pressure control valve,
A low-pressure reservoir that stores the brake fluid that has flowed out of the wheel brakes by the fluid pressure control valve, a positive displacement pump that returns the brake fluid in the low pressure reservoir to the fluid pressure passage, and an electric motor that drives the positive displacement pump. Brake fluid pressure control actuators for vehicles that are assembled into one actuator body are well known, and are described in, for example, the Toyota Crown Hardtop New Vehicle Manual (issued on August 17, 1993 by Toyota Motor Corporation Service Department) It is described on pages 2 to 3-9.

The positive displacement pump described above is generally a plunger type pump, the drive shaft of which is arranged in a hole extending horizontally in the actuator body, and a hole extending in the actuator body at a right angle to the hole and in the horizontal direction. A plunger is hydraulically and slidably fitted therein. Even if the brake fluid leaks due to damage to the seal member that liquid-tightens the sliding part between the plunger and the hole, the drive shaft is generally arranged to drain the leaked brake fluid to the outside and prevent the motor from malfunctioning. The actuator body is provided with a leakage brake fluid discharge hole extending downward from the hole and opening to the lower surface of the actuator.

Further, although the electromagnetic drive portion of the electric motor and the hydraulic pressure control valve attached to the actuator body has a waterproof structure, it is breathable from the butting portion between the housing of the electric motor and the cover of the electromagnetic drive portion and the actuator body. Water may enter, and in order to prevent the intrusion of water due to this breathing action and the ingress of water to the outside to prevent the failure of the electric motor or electromagnetic drive unit, generally, the cover of the electric motor housing or electromagnetic drive unit is There is a breathing hole at the bottom.
The breathing hole is formed in a labyrinth because the cover of the electric motor housing and the electromagnetic drive section is thin and serves as a water inlet when the hole is a simple hole.

[0005]

However, when the leaked brake fluid discharge hole is provided as described above and the breathing holes are separately provided in the housing of the electric motor and the cover of the electromagnetic drive unit, when viewed as the whole actuator. The possibility of water intrusion increases, and the possibility of failure due to water infiltration increases.

According to the invention of this application, the brake fluid leaked through the hole in which the drive shaft of the positive displacement pump is arranged can be discharged to the outside,
Prevents water from invading into the internal space of the motor housing or electromagnetic drive cover due to breathing action, and when water invades, it can be discharged to the outside, and water can enter from the brake fluid or water discharge passages. It is an object of the present invention to provide a vehicle brake fluid pressure control actuator that is less effective than conventional devices.

[0007]

The brake fluid pressure control actuator for a vehicle according to the invention of the present application according to the above object,
It is inserted in the hydraulic pressure path from the brake master cylinder of the vehicle to the wheel brakes, and is an electromagnetically operated hydraulic pressure control valve that controls the flow of brake fluid into and out of the wheel brakes. The low pressure reservoir for storing the brake fluid that has flowed out from the wheel brake by the positive pressure pump, the positive displacement pump that returns the brake fluid in the low pressure reservoir to the hydraulic pressure path, and the electric motor that drives the positive displacement pump are provided in one actuator body. A vehicle brake fluid pressure control actuator assembled, wherein a drive shaft of the positive displacement pump is rotatably disposed in a hole formed in the actuator body so as to extend in a horizontal direction, and the drive shaft is driven. The electric motor is attached to a side surface of the actuator body, and a leakage brake fluid discharge hole extending downward from the hole is provided. The actuator body is formed with an electromagnetic drive unit of the hydraulic control valve and a cover for covering the electromagnetic drive unit is attached to a side surface of the actuator body, and the electromagnetic drive unit of the hydraulic control valve and the electromagnetic drive unit are provided. A cover for covering the electromagnetic drive unit is attached to a side surface of the actuator body, and a lowermost part of an inner space of the cover and / or a lowermost part of an inner space of a housing of the electric motor is located above an upper end of the leaked brake fluid discharge hole. Is also disposed below and communicates with the leaked brake fluid discharge hole by a horizontal breathing hole formed in the actuator body.

[0008]

In the brake fluid pressure control actuator configured as described above, the brake fluid exposed in the hole in which the drive shaft of the positive displacement pump is arranged is discharged to the outside through the leaked brake fluid discharge hole. Further, since the internal space of the cover of the electromagnetic drive unit and / or the internal space of the housing of the electric motor communicates with the outside air through the breathing hole and the leaked brake fluid discharge passage in order, the intrusion of water due to the breathing action is prevented, When water invades, the infiltrated water is discharged through the breathing hole and the leaked brake fluid discharge hole in order.

As described above, by utilizing the leaked brake fluid discharge hole as an outside air side portion of the breathing hole in the inner space of the cover of the electromagnetic drive section and / or the inner space of the housing of the electric motor, there is a possibility that water may leak. Is reduced and the possibility of failure due to flooding is reduced. In addition, the actuator body is much thicker than the electromagnetic drive cover and the motor housing, and the length of the breathing hole is naturally long, so that the possibility of water infiltration is further reduced.

[0010]

Embodiments of the invention of this application will be described with reference to the drawings.

FIG. 1 shows a front left wheel brake and a rear right wheel brake in one of the two pressure chambers of the master cylinder, and a front right wheel brake and a rear left wheel brake in the two pressure chambers of the master cylinder. 2 is a schematic hydraulic pressure path of a brake hydraulic pressure control actuator applied to a hydraulic brake device for an FF vehicle (front engine / front drive vehicle) connected to the other pressure chamber. In FIG. 1, the brake operating force applied to the brake pedal 10 is doubled by a negative pressure type booster 11 and applied to a tandem type master cylinder 12. As well known, the master cylinder 12 has two pressure chambers. Front, rear, left and right four wheel brakes 13, 14, 1
Among them, the left front wheel brake 13 and the right rear wheel brake 14 are connected to one of the two pressure chambers of the master cylinder via an actuator 15, and the right front wheel brake 16 and the left rear wheel brake 17 are connected. Is connected via an actuator 18 to the other pressure chamber of the two pressure chambers of the master cylinder.

The actuator 15 includes a two-port two-position normally open electromagnetic shutoff valve 19 capable of shutting off the front left wheel brake 13 from one pressure chamber of the master cylinder 12, and one rear pressure wheel brake 14 to the master cylinder 12 at one pressure. 2 port 2 position normally open type electromagnetic shutoff valve 20 capable of shutting off from the chamber,
The check valves 21 and 22 arranged in parallel with the electromagnetic cutoff valves 19 and 20 and allowing only the flow of the brake fluid from the wheel brake side to the master cylinder side, and the left front wheel brake 13 in a single low pressure reservoir 23. In the low-pressure reservoir 23, a 2-port 2-position normally-closed electromagnetic shutoff valve 24 that can be connected, a 2-port 2-position normally-closed electromagnetic shutoff valve 25 that can connect the right rear wheel brake 14 to the low-pressure reservoir 23. Brake fluid of a constant volume damper chamber 26 and orifice 27
Through the electromagnetic shutoff valves 19 and 20 and the master cylinder 1
2 and a plunger type pump 28 as a positive displacement pump driven by an electric motor.

The actuator 18 includes a normally open type electromagnetic shut-off valve 29 at the 2-port 2-position capable of shutting off the right front wheel brake 16 from the other pressure chamber of the master cylinder 12, and the left rear wheel brake 17 at the other pressure of the master cylinder 12. 2 port 2 position normally open type electromagnetic shutoff valve 30 capable of shutting off from the chamber,
The check valves 31 and 32, which are arranged in parallel with the electromagnetic cutoff valves 29 and 30 and allow only the brake fluid flow from the wheel brake side to the master cylinder side, and the right front wheel brake 16 are provided in a single low pressure reservoir 33. In the low-pressure reservoir 33, the normally-closed electromagnetic shut-off valve 34 of the 2-port 2-position that can be connected, the normally-closed electromagnetic shut-off valve 35 of the 2-port 2-position that can connect the left rear wheel brake 17 to the low-pressure reservoir 33. The brake fluid of the damper chamber 36 and the orifice 37 of a constant volume.
Through the electromagnetic shut-off valves 29, 30 and the master cylinder 1
2 and a plunger pump 38 driven by an electric motor, which pumps the fluid to a hydraulic pressure path.

A single electric motor 39 drives both plunger pumps 28,38.

Solenoid shutoff valves 19, 20, 24, 25, 2
Reference numerals 9, 30, 34 and 35 constitute hydraulic pressure control valves.

The detailed structure of the assembly (actuator for controlling the brake hydraulic pressure) of the actuators 15 and 18 and the electric motor 39 shown in FIG. 1 is shown in FIGS. 2 is a bottom view of the assembly, FIG. 3 is a left side view, and FIG. 4 is G- in FIG.
5 is a sectional view taken along the line G, FIG. 5 is a partially omitted sectional view taken along the line HH in FIG. 3, and FIG. 6 is a partially omitted sectional view taken along the line JJ in FIG. An actuator body (hereinafter, simply referred to as body) 102 having two rubber mounts 101 for mounting on a vehicle on the left side surface of the lower portion and one on the right side surface thereof.
From the master cylinder 12 to the wheel brakes 13, 14,
16 and 17, that is, the hydraulic pressure path from the point A in FIG. 1 to the points B and C, and the point D
A hydraulic path is formed from the point indicated by to the point indicated by points E and F. On the upper part of this body 102, points A to F in FIG.
There are 6 ports corresponding to the locations indicated by
Ports 103 and 104 corresponding to points A and B appear in FIG.

As shown in FIGS. 4 and 5, a hole 105 formed in the body 102 and opened on the left side surface of the body 102 is driven by an electric motor 39 coupled to the left side surface of the body 102. Plunger type pump 2
8 and 38 are fitted to a drive shaft 106, two ball bearings 107 for rotatably supporting both ends of the drive shaft 106 on the body 102, and an eccentric portion between both ends of the drive shaft 104. A ball bearing 108 is incorporated. Ball bearing 1
Pump plungers 109, 110 of the plunger type pumps 28, 38 are liquid-tightly and slidably incorporated in holes formed in a direction orthogonal to the hole 105 on the outer peripheral side of 08. The pump plungers 109 and 110 are engaged with the outer periphery of the eccentric portion of the drive shaft 106 via a ball bearing 108.

As shown in FIG. 5, the plug chamber 111 is formed by fitting and fixing the plug 111 in the hole opening in the front surface of the body 102, and the plug 112 is fitting in the hole opening in the rear surface of the body 102. The damper chamber 36 is fixedly formed. In FIG. 5, reference numeral 39a indicates an output shaft of the electric motor.

As shown in FIG. 6, on the right side surface of the body 102, the electromagnetic shutoff valves 19, 20, 24, 25, 29,
Electromagnetic drive units 30, 34 and 35 and a cover 113 for covering them are attached. The valve portion driven by these electromagnetic drive portions is incorporated in the body 102. In FIG. 6, the electromagnetic drive parts 19a, 24a and the valve parts 19b, 24b of the electromagnetic cutoff valves 19, 24 are shown. The cover 113 includes a frame member 113A made of an electrically insulating material and a lid member 1 made of an electrically insulating material, which surrounds the electromagnetic drive unit.
13B and the frame member 113A has a connector portion 113Aa shown in FIG. A large number of connector terminals located in the connector portion 113Aa, connection terminals electrically connected to terminals of the electromagnetic drive portions of the electromagnetic cutoff valves 19, 20, 24, 25, 29, 30, 34, and 35, and the motor 39. The bus bar 114 having the connection terminals to which the terminals 39a and 39b (see FIG. 4) are electrically connected is arranged in the cover 113. As shown in FIG. 4, the terminals 39 a and 39 b of the electric motor 39 are connected to the body 102.
Member 11 passing through the through holes 115 and 116 reaching the right side surface from the left side surface of the frame and the through hole of the frame member 113A.
7, 118 electrically connect to the connection terminals of the bus bar 114. The conductive member 117 on the plus side is the body 10.
A pipe 119 made of an electrically insulating material is arranged in the hole 115 so as not to be short-circuited with the two.

In FIG. 4, a low pressure reservoir 23 is arranged below the body 102. The low-pressure reservoir 23 is opened on the lower surface of the body 102 so that the body 1
A piston 121 which is fitted in a hole formed in 02 in a liquid-tight and slidable manner to form a brake fluid chamber 120 between the hole and the bottom of the hole, and a snap ring which is fitted in the body 102. The piston stopper 122 is locked to the body 102 and is substantially fixed, and the compression coil spring 123 is stretched between the piston stopper 122 and the piston 120. An air chamber is provided between the piston stopper 122 and the piston 120, and a hole formed in the piston stopper 122 is used to connect to the atmosphere through a breathing hole of a dust cover 124 attached to the piston stopper 122. ing.

In FIG. 6, in the body 102, the brake fluid leaked into the hole 105 due to the collapse of the liquid tight state of the sliding portions of the pump plungers 109 and 110 is discharged from the lower portion of the hole 105 to the outside of the body. A leaked brake fluid discharge hole 125 is formed which extends downward and opens on the lower surface of the body. The leaked brake fluid discharge hole 125 intersects the hole 116, and the diameter of the portion above the hole 116 is smaller than the diameter of the portion below the hole 116. Cover 11
A seal member 126 is provided at the joint between the frame member 113A and the body 102, and a seal member 127 is provided at the joint between the frame member 113A and the lid member 113B. The lowermost part of the internal space of the cover 113 is located slightly below the hole 116, and communicates with the leaked brake fluid discharge hole 125 by a horizontal breathing hole 128 formed in the body 102.

The lowermost part of the housing of the electric motor 39 is shown in FIG.
Further, a protrusion 129 shown in FIG. 4 is provided, and a maze-like breathing hole is formed in the protrusion 129. A seal member 130 is interposed between the housing of the electric motor 39 and the body 102. As in the second embodiment of FIG. 7, the lowermost part of the internal space of the housing of the electric motor 39 is positioned slightly below the hole 116, and the horizontal breathing hole 131 formed in the body 102 allows the leaked brake fluid discharge hole 1
25 may be communicated. In FIG. 7, the protrusion 129 of the first embodiment is omitted.

In FIG. 1, the electromagnetic shutoff valves 19, 20, 2 are shown.
4, 25, 29, 30, 34, 35 and the electric motor 39 are electrically operated by an electronic control unit (not shown) so as to avoid locking of the wheels in accordance with the behavior of the wheels during vehicle braking. As is well known, the electronic control unit detects the behavior of each wheel by a signal from a rotation sensor mounted on each wheel, determines the necessity of reducing or increasing the brake fluid pressure of each wheel brake, and determines the electromagnetic shutoff valve. And the electric motor 39 is operated. When the vehicle is running, the electromagnetic shutoff valve 1
9, 20, 24, 25, 29, 30, 34, 35 are not operated and occupy the positions shown in FIG.
Is not activated.

When the driver applies a brake operating force to the brake pedal 10 to brake the running vehicle,
Brake fluid is pumped from one pressure chamber of the master cylinder 12 to the left front wheel brake 13 and the right rear wheel brake 14, and from the other pressure chamber of the master cylinder 12 to the right front wheel brake 16 and the left rear wheel brake 17, respectively.
The brake fluid pressure of the wheel brakes 13, 14, 16 and 17 is increased to a fluid pressure corresponding to the brake operating force, and the wheel brakes 13, 14, 16 and 17 increase the left front wheel, the right rear wheel, the right front wheel and the left rear wheel. A braking force corresponding to the brake operation force is applied to each.

While the vehicle is being braked, the electronic control unit can move the
When any one of the two wheels, for example, the right rear wheel, tends to lock, and it is determined that the brake fluid pressure of the right rear wheel brake 14 needs to be reduced, the electromagnetic cutoff valve 2 is determined by the electronic control unit.
1, 25 and the electric motor 39 are operated. This allows
The right rear wheel brake 14 is disconnected from one pressure chamber of the master cylinder 12 and connected to the low pressure reservoir 23, and the brake fluid of the right rear wheel brake 14 flows out to the low pressure reservoir 23, whereby the brake fluid pressure of the same wheel brake 14 is increased. The pressure is suddenly reduced. The brake fluid that has flowed into the low-pressure reservoir 23 is driven by an electric motor 39 and is a plunger pump 28.
Is returned to the master cylinder 12 side through the damper chamber 26 and the orifice 27, and the discharge pulsation of the plunger type pump is damped in the damper chamber 26 and the orifice 27. When the electronic control unit continues to operate the electromagnetic cutoff valve 20 and simultaneously releases and operates the electromagnetic cutoff valve 25 in a predetermined cycle, the brake fluid of the left rear wheel brake 14 flows into the low pressure reservoir 23 in pulses, The brake fluid pressure of the wheel brake 14 is gradually reduced in a stepwise manner. When the electronic control unit determines that the lock tendency of the right rear wheel is released and releases the operation of the electromagnetic cutoff valves 20 and 25, the brake fluid stops flowing from the right rear wheel brake 14 to the low pressure reservoir 23, and the master cylinder 12 The brake fluid on the side is pumped to the right rear wheel brake 14 through the electromagnetic cutoff valve 20, and the brake fluid pressure of the right rear wheel brake 14 is rapidly increased. When the electronic control unit determines that the right rear wheel tends to be locked and repeats the operation and release of the electromagnetic cutoff valve 20 at a predetermined cycle, the brake fluid on the master cylinder 12 side is pulsed to the right rear wheel brake 14. Inflow, the brake fluid pressure of the wheel brake 14 is gradually increased in a stepwise manner.

The electric motor 39 is not stopped until the antilock control for all wheels is completed.

When the electronic control device also tends to lock the left rear wheel during braking of the vehicle and it is determined that the brake fluid pressure of the left rear wheel brake 17 needs to be reduced, the electronic control devices cause the electromagnetic shut-off valves 30, 35 to operate. Is activated. As a result, the left rear wheel brake 17 is cut off from the other pressure chamber of the master cylinder 12 and connected to the low pressure reservoir 33, and the brake fluid of the left rear wheel brake 17 flows out to the low pressure reservoir 33, whereby the brake of the same wheel brake 17 is released. The liquid pressure is suddenly reduced. The brake fluid that has flowed into the low-pressure reservoir 33 is returned to the master cylinder 12 side through a damper chamber 36 and an orifice 37 by a plunger pump 38 driven by an electric motor 39, at which time the discharge pulsation of the plunger pump is changed to the damper chamber 36 and the orifice 37. Attenuated with and. When the electronic control unit continues to operate the electromagnetic cutoff valve 30 and simultaneously releases and operates the electromagnetic cutoff valve 35 in a predetermined cycle, the brake fluid of the right rear wheel brake 17 flows out to the low pressure reservoir 33 in a pulse form, The brake fluid pressure of the wheel brake 17 is gradually reduced stepwise. The electronic control unit determines that the locking tendency of the left rear wheel has been resolved, and the electromagnetic shutoff valve 3
When the operation of 0, 35 is released, the outflow of the brake fluid from the left rear wheel brake 17 to the low pressure reservoir 33 is stopped, and the brake fluid on the master cylinder 12 side is pumped to the left rear wheel brake 17 through the electromagnetic shutoff valve 30 and the right rear wheel brake 17 is released. The brake fluid pressure of the rear wheel brake 17 is rapidly increased. When the electronic control unit determines that the left rear wheel tends to be locked and repeats the operation and release of the electromagnetic cutoff valve 30 at a predetermined cycle, the brake fluid on the master cylinder 12 side is pulsed to the left rear wheel brake 17. Inflow, the brake fluid pressure of the wheel brake 17 is gradually increased in a stepwise manner.

With respect to the brake fluid pressures of the front left wheel brake 13 and the front right wheel brake 16, the electronic shut-off valves 19, 24, 29, 34 are also activated and deactivated by the electronic control unit to suddenly reduce pressure, gradually reduce pressure, rapidly increase pressure, and gradually increase pressure. It is pressured.

The specific construction of the hydraulic pressure control valve for controlling the inflow / outflow of the brake fluid to / from the wheel brakes is not limited to the construction of the first embodiment, but can be appropriately changed if necessary. .

[0030]

As described above, in the vehicle brake fluid pressure control actuator according to the invention of the present application, the leaked brake fluid discharge hole is provided in the internal space of the cover of the electromagnetic drive section and / or the internal space of the housing of the electric motor. By using it as the outside air side portion of the breathing hole of, the opening that may be flooded is reduced and the possibility of failure due to flooding is reduced. In addition, the actuator body is much thicker than the electromagnetic drive cover and the motor housing,
The length of the breathing hole is naturally long, and the possibility of flooding is further reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a hydraulic path of a first embodiment of the invention of this application.

2 is a bottom view of the brake fluid pressure control actuator shown in FIG. 1. FIG.

3 is a left side surface of the brake fluid pressure control actuator shown in FIG.

4 is a cross-sectional view taken along the line GG in FIG.

5 is a partially omitted cross-sectional view taken along the line HH in FIG.

6 is a partially omitted cross-sectional view taken along the line JJ in FIG.

FIG. 7 is a diagram showing a second embodiment of the invention of this application.

[Explanation of symbols]

12 ... Master cylinder 13 ... Left front wheel brake 14 ... Right rear wheel brake 15,115 ... Actuator 16 ... Right front wheel brake 17 ... Left rear wheel brake 18, 118 ... Actuator 19, 20, 24, 25, 29, 30, 34, 35 ...
・ Electromagnetic shut-off valve 23, 33 ... Low pressure reservoir 28, 38 ... Plunger type pump 39 ... Electric motor 102 ... Actuator body 105 ... Hole 106 ... Plunger type Pump drive shaft 113 ... Cover 125 ... Leakage brake fluid discharge hole 128, 131 ... Breathing hole

Claims (1)

[Claims] 1. A hydraulic pressure passage extending from a brake master cylinder of a vehicle to a wheel brake,
An electromagnetically operated hydraulic pressure control valve that controls the flow of brake fluid into and out of the wheel brakes, a low-pressure reservoir that stores the brake fluid that has flowed out of the wheel brakes with this fluid pressure control valve, and a brake fluid in this low-pressure reservoir. In a vehicle brake fluid pressure control actuator in which a positive displacement pump for returning the hydraulic pressure to the hydraulic pressure passage and an electric motor for driving the positive displacement pump are assembled in one actuator body, the brake hydraulic pressure control actuator is formed to extend in the horizontal direction in the actuator body. The drive shaft of the positive displacement pump is rotatably arranged in the hole, and the electric motor for driving the drive shaft is attached to the side surface of the actuator body. A hole is formed in the actuator body to connect the electromagnetic drive unit of the hydraulic control valve and the electromagnetic drive unit. A cover is attached to the side surface of the actuator body, and the lowermost part of the inner space of the cover and / or the lowermost part of the inner space of the housing of the electric motor is arranged below the upper end of the leakage brake fluid discharge hole. A brake fluid pressure control actuator for a vehicle, which is communicated with the leaked brake fluid discharge hole by a horizontal breathing hole formed in the actuator body.