Brake fluid pressure control device

[Problem] The present invention provides a brake hydraulic pressure controller capable of suppressing vibrations of the brake hydraulic pressure controller by lowering a position of center of gravity of the brake hydraulic pressure controller at the time of being mounted on a vehicle.[Means for Resolution] A brake hydraulic pressure controller for a four-wheeled motor vehicle that controls a hydraulic pressure of a brake hydraulic circuit includes: a housing; a motor mounted on a first surface of the housing; and plural electromagnetic control valves mounted on a second surface that opposes the first surface of the housing. The plural electromagnetic control valves are arranged in plural rows from a near side to a far side from a third surface that continues perpendicularly from both of the first surface and the second surface. Two circuit control valves and four booster regulators are arranged in the same row. The two circuit control valves are arranged in channels that connect piping ports, to which piping connected to a master cylinder is connected, and discharge sides of pumps driven by the motor. The four booster regulators are arranged in channels that connect the circuit control valves and piping ports, to which piping connected to wheel cylinders is connected.

BACKGROUND OF THE INVENTION

The present invention relates to a brake hydraulic pressure controller.

Conventionally, a brake hydraulic pressure controller that executes brake control by controlling a hydraulic pressure of a brake fluid to be supplied to a braking section in a hydraulic circuit has been known. The brake hydraulic pressure controller includes a hydraulic unit and an electronic control unit (ECU).

The hydraulic unit includes plural electromagnetic control valves, a pump, a motor for driving the pump, and the like. These plural electromagnetic control valves and the motor are operated under control by the ECU. When the hydraulic pressure in the brake hydraulic circuit is increased or reduced, a braking force generated in a wheel is controlled (for example, see JP-A-2016-203880).

The plural electromagnetic control valves are mounted on a surface of a housing. The surface opposes a surface to which the motor is attached. In addition, at least a part of a piping port, to which piping is connected, is formed in a surface which perpendicularly continues from both of the mounting surface of the motor and the mounting surface of the plural electromagnetic control valves in the housing. The plural electromagnetic control valves are arranged in plural rows from a near side to a far side from the surface to which the piping port is formed.

The brake hydraulic pressure controller mounted on a four-wheeled motor vehicle usually includes the 12 electromagnetic control valves. In general, the plural electromagnetic control valves are mounted on the single surface of the housing such that a maximum of the four electromagnetic control valves are arranged in the single row (for example, see JP-A-2005-145239). Lengths in two directions of the single surface, on which the plural electromagnetic control valves are mounted, in the housing are set in accordance with such arrangement of the plural electromagnetic control valves.

SUMMARY OF THE INVENTION

When the brake hydraulic pressure controller is mounted on the vehicle, the brake hydraulic pressure controller is usually mounted such that the mounting surface of the motor and the mounting surface of the plural electromagnetic control valves face a lateral direction while the surface in which at least the part of the piping port is formed faces upward. In the cases where the number of the electromagnetic control valves arranged in the single row is set to be the maximum of four as in the conventional brake hydraulic pressure controller and where the surface formed with the piping port is set as an upper surface, it is difficult to reduce size of the housing in a height direction. Thus, center of gravity of the brake hydraulic pressure controller is located high, and the brake hydraulic pressure controller tends to be unbalanced at the time of being mounted on the vehicle. As a result, the brake hydraulic pressure controller is likely to vibrate, and sound and vibration properties are possibly deteriorated. Meanwhile, there is a case where a yaw rate sensor and an acceleration sensor are mounted on the ECU of the brake hydraulic pressure controller. In such a case, when the brake hydraulic pressure controller tends to vibrate, sensing properties of these sensors are possibly deteriorated.

The present invention has been made in view of the above problem and therefore provides a brake hydraulic pressure controller capable of suppressing vibrations of the brake hydraulic pressure controller by lowering a position of center of gravity of the brake hydraulic pressure controller at the time of being mounted on a vehicle.

According to one aspect of the present invention, a brake hydraulic pressure controller for a four-wheeled motor vehicle that controls a hydraulic pressure in a brake hydraulic circuit is provided. The brake hydraulic pressure controller includes: a housing; a motor mounted on a first surface of the housing; and plural electromagnetic control valves mounted on a second surface that opposes the first surface of the housing. The plural electromagnetic control valves are arranged in plural rows from a near side to a far side from a third surface that continues perpendicularly from both of the first surface and the second surface. Two circuit control valves and four booster regulators are arranged in the same row. The two circuit control valves are arranged in channels that connect piping ports, to which piping connected to a master cylinder is connected, and discharge sides of pumps driven by the motor. The four booster regulators are arranged in channels that connect the circuit control valves and piping ports, to which piping connected to wheel cylinders is connected.

As it has been described so far, according to the present invention, vibrations of the brake hydraulic pressure controller can be suppressed by lowering a position of center of gravity of the brake hydraulic pressure controller at the time of being mounted on the vehicle.

DETAILED DESCRIPTION

A detailed description will hereinafter be made on a preferred embodiment of the present invention with reference to the accompanying drawings. In this specification and the drawings, components that have substantially the same functional configurations will be denoted by the same reference signs, and thus a description thereon will not be repeated.

Referring toFIG. 1, a brief description will be made on a brake hydraulic circuit1to which a brake hydraulic pressure controller10according to this embodiment can be applied.

The brake hydraulic circuit1illustrated inFIG. 1is a hydraulic circuit in a brake system for a four-wheeled motor vehicle. Such a brake hydraulic circuit1is applied to a brake system that increases a depression force of a brake pedal by a driver without using a booster and transmits the increased depression force to a wheel cylinder. However, the booster may be used in an example of the brake system herein.

The brake hydraulic circuit1includes a first hydraulic circuit28and a second hydraulic circuit30, both of which have the same configuration as each other. A brake fluid is supplied from a master cylinder14to each of the first hydraulic circuit28and the second hydraulic circuit30.

The brake hydraulic circuit1is configured as of a so-called X-shaped piping type in which each of the first hydraulic circuit28and the second hydraulic circuit30controls a hydraulic pressure of a pair of a front wheel and a rear wheel at diagonal positions in the vehicle. Note that the brake system is not limited to that of the X-shaped piping type.

The second hydraulic circuit30has the same configuration as the first hydraulic circuit28. A brief description will hereinafter be made on the first hydraulic circuit28, and a description on the second hydraulic circuit30will not be made.

The first hydraulic circuit28includes a pump element44athat is driven by a motor96. The first hydraulic circuit28also includes an accumulator71aand a damper73a.

The pump44ais driven by the motor96and discharges the brake fluid. Driving of the motor96is controlled by an ECU90. The number of the pump44aprovided in the first hydraulic circuit28is not limited to one.

A first pressure sensor24is provided in a pipeline that communicates with the master cylinder14. The first pressure sensor24detects an internal pressure of the master cylinder14.

A second pressure sensor26ais provided in a pipeline that communicates with a wheel cylinder38ain a hydraulic brake22aof a front right wheel. The second pressure sensor26adetects an internal pressure of the wheel cylinder38a.

The second pressure sensor26amay be provided in a pipeline that communicates with a wheel cylinder38bin a hydraulic brake22bof a rear left wheel, and may detect an internal pressure of the wheel cylinder38b.

The first hydraulic circuit28includes plural electromagnetic control valves. The plural electromagnetic control valves include: a circuit control valve36aof a normally closed type that can be controlled linearly; a suction control valve34aof a normally closed type that is subjected to on/off control; booster regulators58aa,58ba, each of which is of a normally open type and can be controlled linearly; and pressure regulators54aa,54ba, each of which is of the normally closed type and is subjected to the on/off control.

The circuit control valve36ais arranged in a channel33athat connects the master cylinder14and a discharge side of the pump44a. The circuit control valve36acan be controlled linearly and continuously regulates a channel area between the master cylinder14and each of the booster regulators58aa,58ba.

The suction control valve34ais arranged in a channel31athat connects the master cylinder14and a suction side of the pump44a. The suction control valve34acommunicates or blocks between the master cylinder14and the suction side of the pump44a.

The booster regulators58aa,58baare respectively arranged in channels51aa,51ba, each of which connect the circuit control valve36aand corresponding one of the wheel cylinders38a,38b. The booster regulators58aa,58bacan be controlled linearly, and continuously regulate a flow rate of hydraulic oil from a side of the master cylinder14and the circuit control valve36ato the wheel cylinder38aside of the hydraulic brake22aof the front right wheel and the wheel cylinder38bside of the hydraulic brake22bof the rear left wheel, respectively.

The pressure regulators54aa,54baare respectively arranged in channels53aa,53ba, each of which connects the suction side of the pump44aand corresponding one of the wheel cylinder38a,38b. Each of the pressure regulators54aa,54bacommunicates or blocks between the suction side of the pump44aand corresponding one of the wheel cylinder38a,38b. The pressure regulators54aa,54bain open states supply the hydraulic oil that has been supplied to the wheel cylinders38a,38bin the hydraulic brakes22a,22bof the front right wheel and the rear left wheel to the accumulator71aand thereby reduces the hydraulic pressures. When opening/closing of each of the pressure regulators54aa,54bais intermittently repeated, the flow rate of the hydraulic oil flowing from each of the wheel cylinders38a,38bto the accumulator71acan be regulated.

The ECU90controls driving of these electromagnetic control valves. Each of the electromagnetic control valves may be of the normally open type or the normally closed type.

The second hydraulic circuit30controls a hydraulic brake22cof a front left wheel and a hydraulic brake22dof a rear right wheel. The second hydraulic circuit30is configured in a similar manner to the first hydraulic circuit28except for points that the wheel cylinder38ain the hydraulic brake22aof the front right wheel in the above description on the first hydraulic circuit28is replaced with a wheel cylinder38cin the hydraulic brake22cof the front left wheel and that the wheel cylinder38bin the hydraulic brake22bof the rear left wheel is replaced with a wheel cylinder38din the hydraulic brake22dof the rear right wheel.

A description will be made on an overall configuration of the brake hydraulic pressure controller10according to this embodiment with reference toFIG. 2andFIG. 3.

FIG. 2is a perspective view in which the brake hydraulic pressure controller10is seen from an attachment surface side of the motor96.FIG. 3is a perspective view in which the brake hydraulic pressure controller10is seen from an attachment surface side of the ECU90. InFIG. 3, the ECU90is not illustrated.

The illustrated brake hydraulic pressure controller10is an apparatus for controlling a braking force on each of the wheels of the four-wheeled motor vehicle. The brake hydraulic pressure controller10includes a hydraulic unit20and the ECU90. The hydraulic unit20is formed with the brake hydraulic circuit1illustrated inFIG. 1.

The hydraulic unit20includes a housing110. The motor96for driving the pumps44a,44bis mounted on a first surface110aof the housing110. The motor96is mounted such that an unillustrated motor shaft96ais directed inward in the housing110.

The ECU90is attached to a second surface110bthat opposes the first surface110aof the housing110. The 12 electromagnetic control valves and the 3 pressure sensors are mounted on this second surface110b. The ECU90is attached to the second surface110bin a manner to cover these electromagnetic control valves and these pressure sensors. The 12 electromagnetic control valves and the 3 pressure sensors are electrically connected to the ECU90.

The 12 electromagnetic control valves include the 2 circuit control valves36a,36b, the 2 suction control valves34a,34b, the 4 booster regulators58aa,58ba,58ab,58bb, and the 4 pressure regulators54aa,54ba,54ab,54bb. The three pressure sensors include the one first pressure sensor24and the two second pressure sensors26a,26b.

Of four surfaces110c,110d,110e,110f, each of which continues perpendicularly from both of the first surface110aand the second surface110b, the third surface110cis formed with six piping ports, to each of which piping is connected. The six piping ports include: two piping ports121a,121b, to each of which the piping connected to the master cylinder is connected; and four piping ports123a,123b,123c,123d, to each of which the piping connected to the wheel cylinder is connected.

On the fourth surface110dand the fifth surface110e, each of which continues perpendicularly from the first surface110a, the second surface110b, and the third surface110c, pump elements40a,40b, which respectively include the pumps44a,44b, are attached, respectively. Each of the pumps44a,44bhas a piston that reciprocates in conjunction with rotation of the motor shaft in the motor96, so as to suction or discharge the brake fluid.

The sixth surface110f, which continues perpendicularly from the first surface110aand the second surface110band opposes the third surface110c, is provided with the unillustrated accumulators.

Support members88a,88b,88c, each of which has a damper function, are fixed to the first surface110aand the fifth surface110e. An unillustrated bracket, which is used to attach the brake hydraulic pressure controller10to a vehicle body, is attached to each of the support members88a,88b,88c, the brake hydraulic pressure controller10is mounted on the vehicle body via such brackets.

Note that positions where the support members88a,88b,88care fixed are not limited to the illustrated positions.

(2-2. Configuration of Housing)

FIG. 4andFIG. 5are explanatory views, each of which illustrates a configuration example of the housing110of the hydraulic unit20.FIG. 4is a perspective view in which an internal configuration of the housing110is indicated by solid lines, andFIG. 5is a front view of the housing110illustrated inFIG. 4.

The housing110is made of light metal such as aluminum or metal, for example. The housing110is formed with internal channels as the channels for the brake fluid. In addition, the housing110has plural attachment sections in which the motor, the two pump elements, the plural electromagnetic control valves, the accumulators, the pressure sensors, and the like are arranged. Each of the attachment sections is a columnar recess that is formed in the housing110by boring, for example.

In the housing110illustrated inFIG. 5, the internal channels or the attachment sections forming the first hydraulic circuit28are provided in a left-half portion, and the internal channels or the attachment sections forming the second hydraulic circuit30are provided in a right-half portion.

The housing110has plural piping ports121a,121b,123a,123b,123c,123das the attachment sections on the third surface110c. The piping that connects the master cylinder14and the first hydraulic circuit28is connected to the piping port121a. The piping that connects the master cylinder14and the second hydraulic circuit30is connected to the piping port121b.

The piping that is connected to the wheel cylinder38ain the hydraulic brake22aof the front right wheel is connected to the piping port123a. The piping that is connected to the wheel cylinder38bin the hydraulic brake22bof the rear left wheel is connected to the piping port123b. The piping that is connected to the wheel cylinder38cin the hydraulic brake22cof the front left wheel is connected to the piping port123c. The piping that is connected to the wheel cylinder38din the hydraulic brake22dof the rear right wheel is connected to the piping port123d.

The housing110has pump mounting sections143a,143bas the attachment sections in the fifth surface110eand the fourth surface110d, respectively. The pump element40ais mounted on the pump mounting section143aof the fifth surface110e. The pump element40bis mounted on the pump mounting section143bof the fourth surface110d.

The housing110has accumulator bores139a,139bas the attachment sections on the sixth surface110f. The accumulators71a,71bare respectively assembled into the accumulator bores139a,139b.

The housing110has a motor mounting section147as the attachment section on the first surface110a. The motor96is mounted on the motor mounting section147. The housing110also has a through-hole145that penetrates from the first surface110aside to the second surface110bside. Electric wiring that connects the motor96and the ECU90, and the like are disposed in the through-hole145.

The housing110has valve mounting sections131ato131d,133ato133b,135ato135b,137ato137d, on each of which one of the plural electromagnetic control valves is mounted, as the attachment sections on the second surface110b.

The booster regulator58aa, which supplies the brake fluid to the wheel cylinder38ain the hydraulic brake22aof the front right wheel, is mounted on the valve mounting section131a. The booster regulator58ba, which supplies the brake fluid to the wheel cylinder38bin the hydraulic brake22bof the rear left wheel, is mounted on the valve mounting section131b. The booster regulator58ab, which supplies the brake fluid to the wheel cylinder38cin the hydraulic brake22cof the front left wheel, is mounted on the valve mounting section131c. The booster regulator58bb, which supplies the brake fluid to the wheel cylinder38din the hydraulic brake22dof the rear right wheel, is mounted on the valve mounting section131d.

The circuit control valve36ain the first hydraulic circuit28is mounted on the valve mounting section133a. The circuit control valve36bin the second hydraulic circuit30is mounted on the valve mounting section133b. The suction control valve34ain the first hydraulic circuit28is mounted on the valve mounting section135a. The suction control valve34bin the second hydraulic circuit30is mounted on the valve mounting section135b.

The pressure regulator54aa, which discharges the brake fluid from the wheel cylinder38ain the hydraulic brake22aof the front right wheel, is mounted on the valve mounting section137a. The pressure regulator54ba, which discharges the brake fluid from the wheel cylinder38bin the hydraulic brake22bof the rear left wheel, is mounted on the valve mounting section137b. The pressure regulator54ab, which discharges the brake fluid from the wheel cylinder38cin the hydraulic brake22cof the front left wheel, is mounted on the valve mounting section137c. The pressure regulator54bb, which discharges the brake fluid from the wheel cylinder38din the hydraulic brake22dof the rear right wheel, is mounted on the valve mounting section137d.

The housing110further has sensor mounting sections141ato141c, on each of which one of the plural pressure sensors is mounted, as the attachment sections on the second surface110b.

The second pressure sensor26a, which detects the internal pressure of the wheel cylinder38ain the hydraulic brake22aof the front right wheel, is mounted on the sensor mounting section141a. The second pressure sensor26b, which detects an internal pressure of the wheel cylinder38cin the hydraulic brake22cof the front left wheel, is mounted on the sensor mounting section141b. The first pressure sensor24, which detects the internal pressure of the master cylinder14, is mounted on the sensor mounting section141c.

(2-3. Arrangement of Electromagnetic Control Valves)

FIG. 6is an explanatory view illustrating arrangement of the plural electromagnetic control valves in the brake hydraulic pressure controller10according to this embodiment.

On the second surface110b, the plural electromagnetic control valves are separately arranged in a first row L1to a third row L3from a near side to a far side from the third surface110c. In the first row L1, a total of the six electromagnetic control valves including the four booster regulators58aa,58ba,58ab,58bband the two circuit control valves36a,36bis arranged.

In the second row L2, the two suction control valves34a,34band the two second pressure sensors26a,26bare arranged. In the third row L3, the fourth pressure regulators54aa,54ba,54ab,54bband the first pressure sensor24are arranged.

In the brake hydraulic pressure controller10according to this embodiment, the six electromagnetic control valves are arranged in the first row L1. In this way, a total of the 12 electromagnetic control valves and the 3 pressure sensors are arranged in the 3 rows. As a result, a distance H between the third surface110cand the sixth surface110fbecomes shorter than a distance W between the fourth surface110dand the fifth surface110e. The brake hydraulic pressure controller10is usually mounted on the vehicle such that the third surface110cformed with the piping ports is located on an upper side. Thus, the height (H) of the brake hydraulic pressure controller10is less than the width (W) thereof.

FIG. 7illustrates a reference example of a brake hydraulic pressure controller in which a maximum of the four electromagnetic control valves is arranged in a single row. In the reference example, the two suction control valves are arranged in the first row L1, and the fourth booster regulators are arranged in the second row L2. In addition, the two circuit control valves and the one pressure sensor are arranged in the third row L3, and the four pressure regulators are arranged in the fourth row L4.

In the brake hydraulic pressure controller according to the reference example, the maximum of the four electromagnetic control valves is arranged in the single row. Thus, the total of the 12 electromagnetic control valves and the single pressure sensor are arranged in the 4 rows. As a result, while the width (W) of the brake hydraulic pressure controller is reduced, the height (H) thereof is increased. Thus, center of gravity C2of the brake hydraulic pressure controller is located relatively high.

Meanwhile, as illustrated inFIG. 6, in regard to the brake hydraulic pressure controller10according to this embodiment, center of gravity C1of the brake hydraulic pressure controller10, to which the motor96, the ECU90, the pump elements40a,40b, and the like are assembled, is located relatively low. Thus, the brake hydraulic pressure controller10, which is fixed to the brackets via the support members88ato88c, can stably be supported. As a result, vibrations of the brake hydraulic pressure controller10are suppressed, and sound and vibration properties are improved.

There is a case where the ECU90in the brake hydraulic pressure controller10includes a yaw rate sensor or an acceleration sensor that is used for brake control such as an electronic stability program (ESP). Since the vibrations of the brake hydraulic pressure controller10according to this embodiment are suppressed, a sensing property of each of these yaw rate sensor and acceleration sensor is improved.

A length in a width (W) direction of the brake hydraulic pressure controller10according to this embodiment is increased. Thus, a diameter of the motor96to be used can be increased.FIG. 8andFIG. 9are explanatory views illustrating size of the motors that can be used in the brake hydraulic pressure controller10according to this embodiment and the brake hydraulic pressure controller according to the reference example, respectively.

As described above, the housing110is formed with the internal channels, the piping ports, and the various attachment sections. In order to suppress a weight increase of the housing110, the housing110is desirably formed as small as possible. Thus, a position of a screw or the like used to fix the motor is often restricted.

In the case of the brake hydraulic pressure controller according to the reference example illustrated inFIG. 9, a space is available in a vertical (height) direction of a housing210with respect to arrangement of a motor220, but no space is provided in a lateral (width) direction. On the contrary, in the case of the brake hydraulic pressure controller10according to this embodiment illustrated inFIG. 8, a space in a lateral (width) direction of the housing110can effectively be used. Thus, a diameter R1of the motor96to be mounted can be larger than a diameter R2of the motor220in the reference example.

Also, in the brake hydraulic pressure controller according to the reference example, the diameter R2of the motor220to be used can be increased by increasing a lateral width of the housing210. However, an increased space becomes a dead space and increases mass of the housing210. Thus, such an increase is not preferred.

As described above, in the brake hydraulic pressure controller10according to this embodiment, the diameter R1of the motor96that can be mounted can be increased. Thus, in the case where output of the motor96is set to be the same, an axial length of the motor96can be reduced. As a result, the position of the center of gravity C1of the brake hydraulic pressure controller10becomes close to a center of a fixed position of the brake hydraulic pressure controller10. In this way, the brake hydraulic pressure controller10can stably be supported.

In the brake hydraulic pressure controller10according to this embodiment, the circuit control valve36a, which is arranged in the first row L1, is arranged between the two booster regulators58aa,58bain the first hydraulic circuit28of the brake hydraulic circuit1. Similarly, in the second hydraulic circuit30, the circuit control valve36b, which is arranged in the first row L1, is arranged between the two booster regulators58ab,58bb.

Since the circuit control valves36a,36bare respectively arranged between the two booster regulators58aa,58baand between the two booster regulators58ab,58bb, the hydraulic circuits formed in the housing110become less complicated. In this way, an excessive increase in size of the housing110is suppressed.

In the brake hydraulic pressure controller10according to this embodiment, the lateral width of the housing110is increased, and the pump elements40a,40bare respectively mounted on the fifth surface110eand the fourth surface110d, which are located in the lateral direction (seeFIG. 5). Accordingly, an axial length of each of the pump elements40a,40bcan be increased, and a relatively large damper space can be provided in each of the pump elements40a,40b. Thus, the dampers (73a,73b) that are separately provided can be omitted, and it is possible to improve an effect of suppressing pressure pulsations of the brake fluid caused by driving of the pumps44a,44b.

The detailed description has been made so far on the preferred embodiment of the present invention with reference to the accompanying drawings. However, the present invention is not limited to such an embodiment. It is obvious that a person who has basic knowledge in the technical field to which the present invention pertains could have easily arrived at various modification examples and correction examples that fall within the scope of the technical idea described in the claims. It is understood that those naturally fall within the technical scope of the present invention.

For example, the brake hydraulic circuit1, which has been described in the above embodiment, includes the dampers73a,73bin the first hydraulic circuit28and the second hydraulic circuit30, respectively. However, these dampers73a,73bmay not be provided.

The brake hydraulic pressure controller10, which has been described in the above embodiment, includes the second pressure sensors26a,26bto detect the internal pressures of the wheel cylinders. However, these second pressure sensors26a,26bmay not be provided.

In the brake hydraulic pressure controller10, which has been described in the above embodiment, the piping ports121a,121b, to which the piping connected to the master cylinder14is connected, and the piping ports123ato123d, to which the piping connected to the wheel cylinders is connected, are all formed in the third surface110c. However, the present invention is not limited to such an example. At least one of the piping ports may be formed in another surface. For example, the piping ports121a,121b, to which the piping connected to the master cylinder14is connected, may be provided in the first surface110a, on which the motor96is mounted.

REFERENCE SIGNS LIST