JP3663639B2 - Brake hydraulic pressure control actuator for vehicles - Google Patents

Description

[0001]
[Industrial application fields]
The invention of this application relates to a vehicle brake hydraulic pressure control actuator.
[0002]
[Prior art]
A vehicle brake fluid pressure control actuator that is inserted in a fluid pressure path from a vehicle brake master cylinder to a wheel brake, an electromagnetically operated fluid pressure control valve that controls the flow of brake fluid into and out of the wheel brake; A low-pressure reservoir for storing brake fluid discharged from the wheel brake by the hydraulic control valve, a positive displacement pump for returning the brake fluid in the low-pressure reservoir to the hydraulic pressure path, and an electric motor for driving the positive displacement pump. Brake fluid pressure control actuators for vehicles assembled on one actuator body are well-known, for example, Toyota Crown Hardtop New Model Car Description (published August 17, 1993, Toyota Motor Corporation Service Department) 3- 2 to 3-9.
[0003]
The positive displacement pump is generally a plunger type pump, and its drive shaft is disposed in a hole extending horizontally in the actuator body, and the plunger is placed in a hole extending perpendicularly to the hole and horizontally in the actuator body. It is slidably fitted in the hydraulic pressure. In order to prevent the failure of the motor by discharging the leaked brake fluid to the outside even if the brake fluid leaks due to damage to the seal member that makes the sliding part of the plunger and the hole fluid-tight, generally a drive shaft is arranged A leakage brake fluid discharge hole extending downward from the hole and opening in the lower surface of the actuator is provided in the actuator body.
[0004]
In addition, although the electromagnetic drive part of the motor and hydraulic control valve attached to the actuator body has a waterproof structure, moisture enters through the breathing action from the abutment part of the motor housing or the cover of the electromagnetic drive part and the actuator body. In order to prevent water intrusion due to this breathing action and intrusion moisture to the outside to prevent failure of the electric motor and electromagnetic drive unit, in general, it should be placed at the bottom of the motor housing and electromagnetic drive unit cover. A breathing hole is provided. This breathing hole is formed in a labyrinth shape because the cover of the motor housing and the electromagnetic drive section is thin and becomes a water inlet when the cover is simple.
[0005]
[Problems to be solved by the invention]
However, providing a leakage brake fluid discharge hole as described above and further providing a breathing hole separately in the motor housing and the cover of the electromagnetic drive unit has a high possibility of water ingress when viewed as the entire actuator. This will increase the possibility of failure due to flooding.
[0006]
The invention of this application can discharge the brake fluid leaked to the hole in which the drive shaft of the displacement pump is arranged, prevent water from entering due to breathing action into the internal space of the motor housing and the electromagnetic drive cover, The purpose of the present invention is to provide a brake fluid pressure control actuator for a vehicle that can discharge it to the outside when it enters, and has a lower possibility of water intrusion from the brake fluid or water discharge passage than the conventional device. To do.
[0007]
[Means for Solving the Problems]
The vehicle brake hydraulic pressure control actuator of the invention of the present application according to the above object is inserted in a hydraulic pressure path from the vehicle brake master cylinder to the wheel brake, and the brake fluid flows into and out of the wheel brake. An electromagnetically operated hydraulic pressure control valve for controlling the pressure, a low pressure reservoir for storing brake fluid discharged from the wheel brake by the hydraulic pressure control valve, and a displacement type for returning the brake fluid in the low pressure reservoir to the hydraulic pressure path A brake hydraulic pressure control actuator for a vehicle in which a pump and an electric motor that drives the positive displacement pump are assembled in one actuator body,
A drive shaft of the positive displacement pump is rotatably disposed in a hole formed in the actuator body so as to extend in the horizontal direction, and the electric motor that drives the drive shaft is attached to a side surface of the actuator body, A leakage brake fluid discharge hole extending downward from the hole is formed in the actuator body, and an electromagnetic drive part of the hydraulic control valve and a cover covering the electromagnetic drive part are attached to the side surface of the actuator body. , At least one of the lowermost portion of the inner space of the cover or the lowermost portion of the inner space of the housing of the electric motor is disposed below the upper end of the leakage brake fluid discharge hole, and is formed in a horizontal direction formed in the actuator body. The breathing hole communicates with the leakage brake fluid discharge hole.
[0008]
[Action]
In the brake fluid pressure control actuator having the above-described configuration, the brake fluid leaked into the hole in which the drive shaft of the positive displacement pump is disposed is discharged to the outside through the leaked brake fluid discharge hole. At least one of the lowermost part of the internal space of the electromagnetic drive cover or the lowermost part of the internal space of the motor housing communicates with the outside air through the breathing hole and the leakage brake fluid discharge hole in order, thereby causing respiration. Infiltration of water is prevented, and when water intrudes, the intrusion water is discharged to the outside through the breathing hole and the leakage brake fluid discharge hole sequentially.
[0009]
In this way, flooding is possible by using the leaked brake fluid discharge hole as the outside air side part of at least one breathing hole at the bottom of the internal space of the electromagnetic drive cover or at the bottom of the internal space of the motor housing. This reduces the possibility of malfunction due to flooding. In addition, the actuator body is much thicker than the cover of the electromagnetic drive unit and the motor housing, and the length of the breathing hole is naturally long, so that the possibility of flooding is further reduced.
[0010]
【Example】
An embodiment of the invention of this application will be described with reference to the drawings.
[0011]
FIG. 1 shows the left front wheel brake and right rear wheel brake in one of the two pressure chambers of the master cylinder, and the right front wheel brake and left rear wheel brake in the other of the two pressure chambers of the master cylinder. 1 shows 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 each chamber. In FIG. 1, the brake operation force applied to the brake pedal 10 is doubled by a negative pressure booster 11 and applied to a tandem master cylinder 12. As is well known, the master cylinder 12 has two pressure chambers. Of the four front and rear wheel brakes 13, 14, 16, and 17, 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 the actuator 15, The right front wheel brake 16 and the left rear wheel brake 17 are connected to the other pressure chamber of the two pressure chambers of the master cylinder via an actuator 18.
[0012]
The actuator 15 shuts off the left front wheel brake 13 from the one pressure chamber of the master cylinder 12 and the two-port two-position normally open electromagnetic shut-off valve 19 that can shut off the left front wheel brake 13 from the one pressure chamber of the master cylinder 12. A two-port two-position normally open type electromagnetic shut-off valve 20 and a check valve which is arranged in parallel with the electromagnetic shut-off valves 19 and 20 and allows only the brake fluid flow from the wheel brake side to the master cylinder side. 21 and 22, a 2-port 2-position normally closed electromagnetic shut-off valve 24 capable of connecting the left front wheel brake 13 to a single low-pressure reservoir 23, and a 2-port capable of connecting the right rear wheel brake 14 to the low-pressure reservoir 23 The two-position normally-closed electromagnetic shut-off valve 25 and the brake fluid in the low-pressure reservoir 23 are sequentially passed through the damper chamber 26 and the orifice 27 having a constant volume, 0 and is composed of a plunger pump 28 of the displacement pump motor drive for pumping the hydraulic passage between the master cylinder 12.
[0013]
The actuator 18 shuts off the right front wheel brake 16 from the other pressure chamber of the master cylinder 12 and the two-port two-position normally-open electromagnetic shut-off valve 29 and the left rear wheel brake 17 from the other pressure chamber of the master cylinder 12. A two-port two-position normally open electromagnetic shut-off valve 30 and a check valve which is arranged in parallel with the electromagnetic shut-off valves 29 and 30 and allows only the brake fluid flow from the wheel brake side to the master cylinder side. 31 and 32, a two-port two-position normally closed electromagnetic shut-off valve 34 capable of connecting the right front wheel brake 16 to a single low pressure reservoir 33, and two ports capable of connecting the left rear wheel brake 17 to the low pressure reservoir 33 A two-position normally-closed electromagnetic shut-off valve 35 and a brake fluid in the low-pressure reservoir 33 are sequentially passed through a damper chamber 36 and an orifice 37 having a constant volume, It is composed of a 0 and the master cylinder 12 plunger pump 38 of the motor drive for pumping the hydraulic passage between.
[0014]
A single motor 39 drives both plunger pumps 28,38.
[0015]
The electromagnetic shut-off valves 19, 20, 24, 25, 29, 30, 34, and 35 constitute a hydraulic control valve.
[0016]
The detailed structure of the assembly (actuator for brake fluid pressure control) 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, FIG. 4 is a sectional view taken along line GG in FIG. 3, and FIG. 5 is a partially omitted sectional view taken along line HH in FIG. 6 is a partially omitted cross-sectional view taken along line JJ in FIG. An actuator body (hereinafter simply referred to as “body”) 102 having two rubber mounts 101 for mounting on the vehicle on the left side and one on the right side of the lower portion is provided from the master cylinder 12 to the wheel brakes 13, 14, 16 and 1, that is, a hydraulic pressure path extending from a position indicated by point A to a position indicated by points B and C, and a hydraulic pressure path extending from a position indicated by point D to a position indicated by points E and F. Form. In the upper part of the body 102, six ports corresponding to the locations indicated by points A to F in FIG. 1 are arranged, and ports 103 and 104 corresponding to the locations indicated by points A and B appear in FIG. ing.
[0017]
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 has a plunger shape driven by an electric motor 39 coupled to the left side surface of the body 102. A drive shaft 106 common to the pumps 28 and 38, 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 are fitted. A ball bearing 108 is incorporated. Pump plungers 109 and 110 of plunger pumps 28 and 38 are incorporated in a hole formed in a direction orthogonal to the hole 105 on the outer peripheral side of the ball bearing 108 in a liquid-tight manner and slidably. These 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.
[0018]
As shown in FIG. 5, the plug 111 is inserted and fixed in the hole opened in the front of the body 102 to form the damper chamber 26, and the plug 112 is inserted and fixed in the hole opened in the back of the body 102. A damper chamber 36 is formed. In FIG. 5, the code | symbol 39a shows the output shaft of an electric motor.
[0019]
As shown in FIG. 6, on the right side surface of the body 102, the electromagnetic drive parts of the electromagnetic shut-off valves 19, 20, 24, 25, 29, 30, 34 and 35 and a cover 113 covering them are attached. . And the valve part driven by these electromagnetic drive parts is incorporated in the body 102. In FIG. 6, the electromagnetic drive parts 19a and 24a and the valve parts 19b and 24b of the electromagnetic cutoff valves 19 and 24 appear. The cover 113 includes a frame member 113A made of an electrically insulating material surrounding the electromagnetic drive unit and a lid member 113B made of an electrically insulating material, and the frame member 113A has a connector portion 113Aa shown in FIG. Yes. A number of connector terminals located in the connector portion 113Aa, connection terminals electrically connected to terminals of the electromagnetic drive portions of the electromagnetic shut-off valves 19, 20, 24, 25, 29, 30, 34 and 35, and an electric motor 39 A bus bar 114 having 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 39a and 39b of the electric motor 39 are connected to the bus bar by the through holes 115 and 116 extending from the left side surface of the body 102 to the right side and the conductive members 117 and 118 passing through the through holes of the frame member 113A. It is electrically connected to 114 connection terminals. A pipe 119 made of an electrically insulating material is disposed in the hole 115 so that the plus-side conductive member 117 is not short-circuited to the body 102.
[0020]
In FIG. 4, a low-pressure reservoir 23 is disposed below the body 102. The low-pressure reservoir 23 is fitted in a fluid-tight and slidable manner in a hole formed in the body 102 so as to open to the lower surface of the body 102, and forms a brake fluid chamber 120 between the bottom of the hole. A piston 121, a piston stopper 122 fitted in the body 102, locked to the body 102 by a retaining ring and substantially fixed, and stretched between the piston stopper 122 and the piston 120. And a compression coil spring 123. The space between the piston stopper 122 and the piston 120 is an air chamber, and is connected to the atmosphere through the breathing hole of the dust cover 124 attached to the piston stopper 122 using the same hole as the hole formed in the piston stopper 122. ing.
[0021]
In FIG. 6, the body 102 extends downward from the lower portion of the hole 105 in order to discharge 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. A leakage brake fluid discharge hole 125 is formed in the lower surface of the body. The leakage brake fluid discharge hole 125 intersects with 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. A seal member 126 is interposed at the joint between the frame member 113A and the body 102 of the cover 113, and a seal member 127 is interposed 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 through a horizontal breathing hole 128 formed in the body 102.
[0022]
A protrusion 129 shown in FIGS. 2 and 4 is provided at the bottom of the housing of the electric motor 39, and a maze-like breathing hole is formed in the protrusion 129. A seal member 130 is interposed at the joint between the housing of the electric motor 39 and the body 102. As shown 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 leaked brake fluid discharge hole 125 is formed by the horizontal breathing hole 131 formed in the body 102. You may make it communicate. In FIG. 7, the protrusion 129 of the first embodiment is eliminated.
[0023]
In FIG. 1, the electromagnetic shut-off valves 19, 20, 24, 25, 29, 30, 34, and 35 and the electric motor 39 are prevented from being locked by the electronic control device (not shown) according to the behavior of the wheel during vehicle braking. It is electrically operated. As is well known, the electronic control unit detects the behavior of each wheel based on a signal from a rotation sensor mounted on each wheel, determines the necessity of pressure reduction and pressure increase of each wheel brake, And the electric motor 39 is operated. When the vehicle is traveling, the electromagnetic shut-off valves 19, 20, 24, 25, 29, 30, 34, and 35 are not operated and occupy the positions shown in FIG. 1, and the electric motor 39 is also operated. Absent.
[0024]
When the driver applies a brake operation force to the brake pedal 10 to brake the traveling vehicle, the left front wheel brake 13 and the right rear wheel brake 14 from one pressure chamber of the master cylinder 12 and the master cylinder 12 On the other hand, the brake fluid is pumped from the pressure chamber to the right front wheel brake 16 and the left rear wheel brake 17, respectively, and the brake fluid pressures of the wheel brakes 13, 14, 16 and 17 are increased to the fluid pressure corresponding to the brake operation force. The brakes 13, 14, 16 and 17 apply braking force corresponding to the brake operation force to the left front wheel, right rear wheel, right front wheel and left rear wheel, respectively.
[0025]
When the electronic control unit determines that any one of the four wheels on the front, rear, left, and right, for example, the right rear wheel, tends to lock during vehicle braking, and the brake fluid pressure of the right rear wheel brake 14 needs to be reduced, The electromagnetic shut-off valves 21 and 25 and the electric motor 39 are operated by the control device. As a result, the right rear wheel brake 14 is disconnected from the 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. The hydraulic pressure is suddenly reduced. The brake fluid that has flowed into the low-pressure reservoir 23 is returned to the master cylinder 12 through the damper chamber 26 and the orifice 27 by the plunger-type pump 28 driven by the electric motor 39. At this time, the discharge pulsation of the plunger-type pump causes the damper chamber 26 and the orifice 27 to discharge. And attenuated. When the electronic control unit continues to operate the electromagnetic shut-off valve 20 and simultaneously repeats the release and operation of the electromagnetic shut-off valve 25 at a predetermined cycle, the brake fluid of the left rear wheel brake 14 flows out into the low-pressure reservoir 23 in a pulsed manner, The brake fluid pressure of the wheel brake 14 is gradually reduced in a stepped manner. When the electronic control unit determines that the right rear wheel locking tendency has been resolved and releases the operation of the electromagnetic shut-off valves 20 and 25, the brake fluid from the right rear wheel brake 14 to the low pressure reservoir 23 stops flowing, and the master cylinder 12 Side brake fluid is pumped to the right rear wheel brake 14 through the electromagnetic shut-off 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 is a sign that the right rear wheel tends to lock and repeats the operation and release of the electromagnetic shut-off valve 20 at a predetermined cycle, the brake fluid on the master cylinder 12 side is pulsed to the right rear wheel brake 14 The brake fluid pressure of the wheel brake 14 is gradually increased stepwise.
[0026]
The electric motor 39 is stopped only when the antilock control for all the wheels is finished.
[0027]
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 electromagnetic shut-off valves 30 and 35 are operated by the electronic control device. . As a result, the left rear wheel brake 17 is disconnected 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 into the low pressure reservoir 33. The hydraulic pressure is suddenly reduced. The brake fluid flowing into the low-pressure reservoir 33 is returned to the master cylinder 12 side through the damper chamber 36 and the orifice 37 by the plunger pump 38 driven by the electric motor 39, and at this time, the discharge pulsation of the plunger pump is the damper chamber 36 and the orifice 37. And attenuated. When the electronic control unit continues to operate the electromagnetic shut-off valve 30 and simultaneously repeats the release and operation of the electromagnetic shut-off valve 35 at a predetermined cycle, the brake fluid of the right rear wheel brake 17 flows into the low pressure reservoir 33 in a pulsed manner. The brake fluid pressure of the wheel brake 17 is gradually reduced in a stepped manner. When the electronic control unit determines that the left rear wheel locking tendency has been resolved and releases the operation of the electromagnetic shut-off valves 30 and 35, the brake fluid flow from the left rear wheel brake 17 to the low pressure reservoir 33 stops, and the master cylinder 12 The brake fluid on the side is pumped to the left rear wheel brake 17 through the electromagnetic shut-off valve 30, and the brake fluid pressure of the right rear wheel brake 17 is rapidly increased. When the electronic control unit determines that the left rear wheel is a sign of a tendency to lock and repeats the operation and release of the electromagnetic shut-off valve 30 at a predetermined cycle, the brake fluid on the master cylinder 12 side is pulsed to the left rear wheel brake 17. The brake fluid pressure of the wheel brake 17 is gradually increased stepwise.
[0028]
As for the brake fluid pressure of the left front wheel brake 13 and the right front wheel brake 16, the electromagnetic shut-off valves 19, 24, 29, and 34 are actuated and released by the electronic control device, and suddenly depressurized, slowly depressurized, rapidly increased, and slowly increased. Is.
[0029]
The specific configuration of the hydraulic pressure control valve that controls the inflow and outflow of the brake fluid to the wheel brake is not limited to the configuration of the first embodiment, and can be changed as appropriate.
[0030]
【The invention's effect】
As described above, the brake fluid pressure control actuator for a vehicle according to the invention of this application has a leakage brake fluid discharge hole at the lowermost part of the inner space of the electromagnetic drive unit cover or the lowermost part of the inner space of the motor housing. By using it as the outside air side portion of at least one of the breathing holes, the number of openings that can be submerged is reduced, and the possibility of failure due to submergence is reduced. In addition, the actuator body is much thicker than the cover of the electromagnetic drive unit or the motor housing, and the length of the breathing hole is naturally long, so that the possibility of flooding is further reduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a hydraulic pressure 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.
FIG. 3 is a left side view of the brake fluid pressure control actuator shown in FIG.
4 is a cross-sectional view taken along line GG in FIG.
5 is a partially omitted cross-sectional view taken along the line HH in FIG. 3. FIG.
6 is a partially omitted cross-sectional view taken along line JJ in FIG. 3;
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 valves 23, 33 ... low pressure reservoirs 28, 38 ... plunger type pump 39 ... electric motor constituting hydraulic pressure control valve 102 ... Actuator body 105 ... Hole 106 ... Plunger pump drive shaft 113 ... Cover 125 ... Leakage brake fluid discharge hole 128, 131 ... Breathing hole

Claims (1)

An electromagnetically operated hydraulic pressure control valve that is inserted in a hydraulic pressure path from a vehicle brake master cylinder to a wheel brake, and that controls the flow of brake fluid into and out of the wheel brake, and the hydraulic pressure control valve A low-pressure reservoir that stores brake fluid that has flowed out of the wheel brake by the above, a positive displacement pump that returns the brake fluid in the low-pressure reservoir to the hydraulic pressure path, and an electric motor that drives the positive displacement pump are combined into one actuator body. In the vehicle brake hydraulic pressure control actuator assembled, a drive shaft of the positive displacement pump is rotatably disposed in a hole formed in the actuator body so as to extend in the horizontal direction, and drives the drive shaft. An 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. Serial is formed in the actuator body, the fluid pressure and the electromagnetic drive portion of the valve and the cover covering the electromagnetic drive unit is attached to a side surface of the actuator body, the bottom or the electric motor of the inner space of the cover At least one of the lowermost part of the inner space of the housing is disposed below the upper end of the leakage brake fluid discharge hole and communicates with the leakage brake fluid discharge hole by a horizontal breathing hole formed in the actuator body. A brake fluid pressure control actuator for a vehicle.

Images