JP2000190839A - Fault judging method of braking device, and braking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fault judging method for a braking device and a braking device which can supply a liquid pressure (oil pressure) to the other piping quickly even if a liquid leakage is generated in one piping and which is structurally low-cost. SOLUTION: Pipings 32, 48, 66, 82 are provided with their respective orifices 102, 106, 110, 114 and pressure sensitive sensors 104, 108, 112, 116. For example, the liquid pressure is not increased in the piping 32 even if a brake liquid is supplied to respective pipings 32, 48, 66, 82 under such state that the liquid leakage of the brake liquid is generated from the piping 32 between the orifice 102 and LF brake 34, but the liquid pressure is increased at the upper streamside than the orifice 102 by the passage resistance of the orifice 102 and following this, the liquid pressure is increased in the pipings 48, 66, 82. In this state, the pressure sensitive sensor 104 does not detect the increase of the liquid pressure, but the pressure sensitive sensors 108∼116 detect the increase of the liquid pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of determining a failure of a braking device in a brake of a vehicle and the like, and a braking device.

[0002]

2. Description of the Related Art Normally, a braking device for a vehicle supplies a hydraulic pressure corresponding to an amount of depression of a brake pedal to both a rear wheel brake and a front wheel brake, and rotates integrally with a wheel which rotates by the hydraulic pressure at this time. A friction material is pressed into contact with a rotor, a drum, or the like, and the friction force at this time is used as a braking force. Two hydraulic lines, a first hydraulic line for supplying hydraulic pressure to the front wheel brake and a second hydraulic line for supplying hydraulic pressure to the left rear wheel brake and the right front wheel brake, are provided. In such a case, a braking device of a type that operates a brake corresponding to the hydraulic piping by using the hydraulic piping of the other system even if a failure occurs.

In this type of braking device, a pair of pistons are arranged coaxially in the cylinder in consideration of cost and the like, and the piston at the open end of the cylinder is displaced toward the bottom of the cylinder. The hydraulic pressure generated between the pair of pistons at the time is supplied to one hydraulic pipe, and the piston at the bottom of the cylinder is displaced toward the bottom of the cylinder by the above-described hydraulic pressure. A braking device using a so-called tandem master cylinder for supplying the generated hydraulic pressure to the other hydraulic piping is generally used.

In the case where the above master cylinder is applied, for example, if liquid leakage occurs in a hydraulic pipe to which hydraulic pressure is supplied between a pair of pistons, the displacement of the piston on the bottom side of the cylinder causes the displacement between the pair of pistons. Because most of the hydraulic pressure leaks without being supplied, the piston at the open end of the cylinder moves until the piston at the bottom end of the cylinder passes through the communicating part between the hydraulic piping where the liquid leaked and the inside of the cylinder. Otherwise, hydraulic pressure cannot be applied to the piston on the bottom side of the cylinder (ie, the piston on the bottom side of the cylinder cannot be displaced). On the other hand, if a leak occurs in the hydraulic pipe on the side to which the hydraulic pressure is supplied between the piston on the bottom side of the cylinder and the bottom of the cylinder, the hydraulic pressure between the pair of pistons is mostly changed by the piston on the bottom side of the cylinder. Until the piston on the bottom side of the cylinder passes through the communication part between the hydraulic pipe where the fluid leaks and the inside of the cylinder, the hydraulic pressure between the pair of pistons is It is not provided to the piping.

[0005]

In the case where the above master cylinder is applied, for example, if liquid leakage occurs in a hydraulic pipe on the side to which hydraulic pressure is supplied between a pair of pistons, displacement of the piston on the bottom side of the cylinder is caused. Since most of the hydraulic pressure leaks without being supplied with the hydraulic pressure between the pair of pistons, the piston on the open end side of the cylinder passes through the communicating portion between the hydraulic pipe where the liquid leaked and the inside of the cylinder. Until the piston at the bottom of the cylinder is approached, hydraulic pressure cannot be applied to the piston at the bottom of the cylinder (that is, the piston at the bottom of the cylinder cannot be displaced). On the other hand, if a leak occurs in the hydraulic pipe on the side to which the hydraulic pressure is supplied between the piston on the bottom side of the cylinder and the bottom of the cylinder, the hydraulic pressure between the pair of pistons is mostly changed by the piston on the bottom side of the cylinder. Until the piston on the bottom side of the cylinder passes through the communicating portion between the hydraulic piping where the fluid leaks and the inside of the cylinder, the hydraulic pressure between the pair of pistons is It is not provided to the piping.

[0006] As described above, in the braking device to which the tandem master cylinder is applied, when liquid leakage occurs in one hydraulic pipe, the liquid leakage occurs unless the piston inside the cylinder reaches a predetermined position as described above. The hydraulic pressure cannot be supplied to the hydraulic piping on the other side.

There is a so-called stepped bore master cylinder as a tandem master cylinder in which such disadvantages are improved. However, the cost of the stepped bore master cylinder is higher than that of a general tandem master cylinder.

In view of the above facts, the present invention can supply hydraulic pressure (hydraulic pressure) to the other pipe immediately even if a liquid leaks in one of the pipes, and has a structurally inexpensive brake. The purpose is to get the device.

[0009]

According to a first aspect of the present invention, a brake fluid pressurized in the same master cylinder is distributed to a plurality of pipes, and a brake connected to each of the plurality of pipes is provided. A brake device failure determining method for determining the brake fluid leakage that has occurred in any of the plurality of pipes, wherein the orifice is provided in each of the plurality of pipes, and a plurality of the orifices are provided from the master cylinder. While increasing the pressure of the brake fluid supplied to each of the pipes between the master cylinder and the orifice, measuring the fluid pressure of the brake fluid flowing between the orifice and the brake in each of the plurality of pipes Then, in a state where a rise in the hydraulic pressure is measured between the orifice and the brake in any of the plurality of pipes, a pipe other than the pipe in which the rise in the hydraulic pressure is measured is connected. In the case of increase of the fluid pressure was not measured, it is determined that the leakage of the brake fluid from the pipe increase of the fluid pressure was not measured occurs, it is characterized in that.

[0010] According to the brake device failure judging method having the above structure, orifices are provided in a plurality of pipes connected to the master cylinder, respectively. When the brake fluid is supplied to the pipe, the brake fluid receives the passage resistance of the orifice in each pipe, and the hydraulic pressure of the brake fluid is increased on the master cylinder side with respect to the orifice of each pipe.

Here, on the downstream side of each pipe from each orifice (ie, on the brake side corresponding to each pipe), the hydraulic pressure of the brake fluid flowing through each pipe between the orifice and the brake is measured. If there is no abnormality in each pipe, each orifice receives passage resistance, but in each pipe, the brake fluid is pressurized up to the brake, so each brake operates, and each pipe has an orifice and brake. The increase in the hydraulic pressure of the brake fluid is measured.

However, if a leak of the brake fluid occurs between the orifice and the brake in any one of the plurality of pipes (hereinafter, referred to as a “failed pipe” for convenience), the orifice and the brake are disconnected in the failed pipe. Does not cause an increase in the hydraulic pressure of the brake fluid between the orifice and the brake.

In the case where any of such pipes becomes a faulty pipe, in the conventional braking device, a pipe other than the faulty pipe and in which no liquid leakage occurs (hereinafter referred to as “non-failure pipe” for convenience). The brake fluid supplied to the non-failed pipe is extremely reduced until the brake fluid to be supplied to the failed pipe also escapes to the failed pipe side or the supply of the brake fluid to the failed pipe is stopped. State.

However, as described above, in the present braking device, each pipe is provided with an orifice, and the passage resistance of the orifice acts on the brake fluid flowing through each pipe.
Since this passage resistance also acts on the brake fluid flowing through the failed pipe, the fluid pressure of the brake fluid is increased upstream of the orifice (that is, on the master cylinder side) also in the failed pipe, whereby The brake fluid is also supplied to the non-failure pipe via the master cylinder. Therefore, an increase in the hydraulic pressure of the brake fluid is measured between the orifice on the non-failure pipe side and the brake.

As described above, the rise in hydraulic pressure of the brake fluid is not measured in the failed pipe due to fluid leakage, but the rise in hydraulic pressure can be measured in the non-failed pipe. When the increase in brake fluid pressure is measured in one of the plurality of pipes when the increase in brake fluid pressure is not detected when there is a pipe that supplies the brake fluid, It can be determined that the pipe for which the increase in the liquid pressure is not measured is a failed pipe (a pipe in which a liquid leak has occurred).

According to a second aspect of the present invention, in the brake device failure judging method according to the first aspect, a valve is provided between each of the plurality of pipes between the orifice and the master cylinder. The rise in the hydraulic pressure was measured in any of the pipes, and when the rise in the hydraulic pressure was not measured in a pipe other than the pipe in which the rise in the hydraulic pressure was measured, the rise in the hydraulic pressure was not measured. The valve corresponding to the pipe is closed.

In the brake device failure judging method having the above-described structure, even if an increase in the brake fluid pressure is measured between the orifice and the brake at any one of the plurality of pipes, the other pipes are not used. If the increase in the brake fluid pressure between the orifice and the brake is not measured, the brake between the orifice and the brake, among the valves provided between the orifice of each pipe and the master cylinder, The valve on the side of the pipe on which the increase in the liquid pressure was not measured (that is, the failed pipe) is closed. This allows
It is possible to prevent the influence of the liquid leakage from the failed pipe on the non-failed pipe side, and to quickly operate the brake on the non-failed pipe side.

According to a third aspect of the present invention, there is provided a braking device having a bottomed cylindrical master cylinder, and a plurality of brake cylinders each having one end connected to the master cylinder, to which brake fluid pressurized inside the master cylinder is distributed and supplied. A pipe, a plurality of brakes provided corresponding to the other ends of the pipes, the brakes being operated by hydraulic pressure of brake fluid supplied from the master cylinder, and the master cylinder provided in each of the plurality of pipes. And a plurality of orifices that increase the hydraulic pressure of the brake fluid between the master cylinder and the master cylinder, and are provided in each of the plurality of pipes, and the orifice and the brake Fluid pressure measuring means for measuring the fluid pressure of the brake fluid flowing through each of the plurality of pipes.

According to the braking device having the above structure, the plurality of pipes connected to the master cylinder are provided with orifices, respectively, and the hydraulic pressure of the brake fluid is increased by the master cylinder, and the brake fluid is supplied to each pipe. Is supplied, the brake fluid receives the passage resistance of the orifice in each pipe, and the hydraulic pressure of the brake fluid is increased on the master cylinder side with respect to the orifice of each pipe.

Here, on the downstream side of each pipe from each orifice (ie, on the brake side corresponding to each pipe), the hydraulic pressure of the brake fluid flowing through each pipe between the orifice and the brake is measured by hydraulic pressure measuring means. Has been measured. When there is no particular abnormality in each pipe, although the passage resistance is received at each orifice, each brake operates in each pipe because the brake fluid is pressurized up to the brake, and
The increase in the hydraulic pressure of the brake fluid between the orifice of each pipe and the brake is measured by hydraulic pressure measuring means.

However, if a leak of the brake fluid occurs between the orifice and the brake in any one of the plurality of pipes (hereinafter, referred to as “failed pipe” for convenience), the orifice and the brake There is no increase in the hydraulic pressure of the brake fluid between the orifice and the brake due to the fluid leakage between the two, and the hydraulic pressure measuring means does not measure the increase in the hydraulic pressure of the brake fluid.

In the case where any of such pipes becomes a faulty pipe, in the conventional braking device, a pipe other than the faulty pipe, in which no liquid leakage occurs (hereinafter, referred to as “non-failure pipe” for convenience) The brake fluid supplied to the non-failed pipe is extremely reduced until the brake fluid to be supplied to the failed pipe also escapes to the failed pipe side or the supply of the brake fluid to the failed pipe is stopped. State.

However, as described above, in the present braking device, each pipe is provided with an orifice, and the passage resistance of the orifice acts on the brake fluid flowing through each pipe.
Since this passage resistance also acts on the brake fluid flowing through the failed pipe, the fluid pressure of the brake fluid is increased upstream of the orifice (that is, on the master cylinder side) also in the failed pipe, whereby The brake fluid is also supplied to the non-failure pipe via the master cylinder. Therefore, the hydraulic pressure of the brake fluid increases between the orifice on the non-failure pipe side and the brake, and the increase in the hydraulic pressure is measured by the fluid pressure measuring means on the non-failure pipe side.

As described above, the hydraulic pressure measuring means on the failed pipe side cannot measure the increase in the hydraulic pressure of the brake fluid due to leakage, but the hydraulic pressure measuring means on the non-failed piping side cannot increase the hydraulic pressure. When the brake fluid is supplied from the master cylinder to each pipe, the hydraulic pressure measurement means measures the increase in the brake fluid pressure in any of the multiple pipes. If the hydraulic pressure measuring means cannot measure the increase in the hydraulic pressure of the brake fluid, the pipe corresponding to the hydraulic pressure measuring means that could not measure the increase in the hydraulic pressure is a defective pipe (a leak has occurred). Pipe).

According to a fourth aspect of the present invention, there is provided a braking device provided in each of the plurality of pipes,
A plurality of valves for opening and closing the piping corresponding to the orifice and the master cylinder, and control means for opening and closing the plurality of valves based on a result of the fluid pressure measurement from the fluid pressure measuring means. Is special.

In the braking device having the above-described structure, the rise of the hydraulic pressure is measured by any of the plurality of hydraulic pressure measuring means.
If the other hydraulic pressure measuring means does not measure the increase in the hydraulic pressure, the hydraulic pressure of the plurality of valves provided between the orifice of each pipe and the master cylinder does not measure the increase in the hydraulic pressure. The valve corresponding to the pressure measuring means (that is, the valve on the side of the failed pipe) is closed by the control means. As a result, it is possible to prevent the influence of the leakage of the liquid from the failed pipe on the non-failed pipe side, and to quickly operate the brake on the non-failed pipe side.

According to a fifth aspect of the present invention, there is provided the braking device according to the third or fourth aspect, wherein the first piston provided inside the master cylinder is connected to the master cylinder via the first piston. A second piston provided on the side opposite to the bottom, and communicating one of the plurality of pipes between the first piston and the master cylinder in the internal space of the master cylinder. And, among the plurality of pipes, pipes other than the pipe communicating with the internal space of the master cylinder between the first piston and the master cylinder, and the second piston and the second piston.
It is characterized in that it is communicated with the internal space of the master cylinder between the piston and the piston.

In the braking device having the above structure, the first and second pistons provided inside the master cylinder are the second pistons.
The piston is moved to the bottom side of the master cylinder, whereby the brake fluid between the first piston and the second piston is compressed and pressurized, so that the brake between the first piston and the second piston is increased. The liquid is supplied to a pipe that communicates with a space between the first piston and the second piston among the plurality of pipes. In addition, the first piston is moved to the bottom side of the master cylinder by the hydraulic pressure of the brake fluid compressed between the first piston and the second piston, so that the first piston moves between the bottom side of the master cylinder and the first piston. The brake fluid is compressed and pressurized, and the brake fluid is supplied to a pipe communicating with a space between the bottom side of the master cylinder and the first piston among the plurality of pipes. That is, the master cylinder of the present braking device is a so-called tandem master cylinder.

Here, the present braking device uses the above-described master cylinder (that is, a tandem master cylinder), but the first piston and the second piston do not sufficiently move to the bottom side of the master cylinder. Even if the brake fluid is supplied to each pipe, the presence / absence of a failed pipe can be determined based on whether or not each fluid pressure measuring means has measured an increase in the hydraulic pressure of the brake fluid.

According to a sixth aspect of the present invention, in the braking device according to the fourth or fifth aspect, the control means detects a state of each part of the vehicle during traveling based on a signal from a sensor group. The invention is characterized in that the plurality of brakes during traveling are controlled by opening and closing the valve.

In the braking device having the above structure, the control means not only opens and closes each valve based on whether or not the increase in the hydraulic pressure is measured from each hydraulic pressure measuring means, but also controls the state of each part of the vehicle when the vehicle is running. Is detected by the sensor group. For example, in a state where the rotation of the wheels is stopped despite the movement of the vehicle, the control means appropriately opens and closes each valve to release a so-called wheel lock. That is, the present braking device employs a so-called anti-lock brake system.

Here, in a braking device employing a so-called anti-lock brake system, as described above, each pipe is provided with a valve, and each valve is controlled by control means. Each valve and control means used in such an antilock brake system can be basically used as it is as a constituent element of the present invention. Therefore, in the present invention, since only the orifice and the fluid pressure measuring means are basically required to be separately provided, it can be realized at a lower cost, and for a vehicle employing the antilock brake system. It can be realized with simple design changes.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 schematically shows a system of a braking device 10 according to an embodiment of the present invention.
As shown in this figure, the braking device 10 includes a master cylinder 12. The master cylinder 12 is entirely cylindrical with a bottom, and a primary piston 14 as a first piston is slidably accommodated therein. A secondary piston 16 as a second piston is slidably housed on the side opposite to the bottom of the master cylinder 12 via the primary piston 14 inside the master cylinder 12. One end of a push rod 18 is connected to an end of the primary piston 14 opposite to the secondary piston 16.

The push rod 18 is connected to the master cylinder 1
2, and the other end in the longitudinal direction protrudes from the open end of the master cylinder 12 to the outside,
It is connected to a brake pedal 22 provided in a vehicle (not shown) through the brake booster 20. The brake pedal 22 is pivotally supported at a predetermined position in the vehicle cabin so as to be swingable around the axis with the vehicle width direction as the axial direction. When the brake pedal 22 is depressed forward, the push rod 18 is moved to the master cylinder. 12 is pressed and moved toward the bottom side. The push rod 1 is pressed by the pressing force from the brake pedal 22.
When 8 moves to the bottom side of master cylinder 12, the boosting mechanism of brake booster 20 amplifies the pressing force. Therefore, the push rod 18 can be moved toward the bottom of the master cylinder 12 with a relatively small pressing force (depressing force) on the brake pedal 22.

On the other hand, a reservoir tank 24 is disposed beside the master cylinder 12. Reservoir tank 24
, A brake fluid is stored therein, and its internal space communicates with the inside of the master cylinder 12 via two lines of piping (not shown). One of the two systems of pipes (not shown) communicates the space between the bottom of the master cylinder 12 and the primary piston 14 and the internal space of the reservoir tank 24 in the inside of the master cylinder 12, and the other. Is the space between the primary piston 14 and the secondary piston 16 and the reservoir tank 24
It communicates with the internal space. The brake fluid is supplied from the reservoir tank 24 to the space between the bottom of the master cylinder 12 and the primary piston 14 and the space between the primary piston 14 and the secondary piston 16 via these two pipes. .

Here, as described above, the push rod 18 is connected only to the secondary piston 16 and is not directly connected to the primary piston 14. When the secondary piston 16 and the primary piston 14 slide to the bottom of the master cylinder 12 due to
, The brake fluid supplied between them is compressed to increase the fluid pressure, whereby the primary piston 14 slides toward the bottom of the master cylinder 12.

Further, as shown in FIG. 1, one end of a pipe 26 is connected to the master cylinder 12. Piping 2
One end of 6 communicates with the space between the primary piston 14 and the bottom of the master cylinder 12 in the internal space of the master cylinder 12, and the other end of the solenoid valve 28 as a valve which is a constituent element of the present invention. It communicates with the inside. The solenoid valve 28 has a solenoid, and is configured to open and close the valve by energization and de-energization accompanying energization and de-energization of the solenoid. As shown in FIG. 2, the solenoid valve 28 is electrically connected to an ABS computer 30 as control means. A control circuit such as a relay (not shown) energizes or deenergizes the solenoid of the solenoid valve 28 in response to a signal from the ABS computer 30.

As shown in FIG. 1, one end of a pipe 32 is connected to the solenoid valve 28, and the solenoid valve 28 is connected to the left side of a pair of front wheels (not shown) of the vehicle via the pipe 32. Are connected to an LF brake 34 as a brake provided corresponding to the wheels of the vehicle.

One end of a pipe 36 is connected to the pipe 32 in the middle thereof, and the solenoid valve 28 is connected to a solenoid valve 38 via the pipe 36.

The solenoid valve 38 has basically the same configuration as the above-described solenoid valve 28, and opens and closes the solenoid valve 38 by energizing and deenergizing the solenoid. The solenoid valve 38 is also electrically connected to the ABS computer 30, and a control circuit (not shown) such as a relay turns on or off the solenoid of the solenoid valve 38 by a signal from the ABS computer 30.

The solenoid valve 38 is connected to a reservoir tank 42 via a pipe 40. When the solenoid valve 38 is open, the brake fluid supplied to the solenoid valve 38 via the pipe 36
Through the reservoir tank 42.

On the other hand, as shown in FIG.
Communicates with one end of the pipe 44 in the middle thereof.
4 is connected to a solenoid valve 46 as a valve which is a constituent element of the present invention. The solenoid valve 46 has a solenoid similarly to the solenoid valve 28, and is configured to open and close the valve by energization and de-energization accompanying energization and de-energization of the solenoid. As shown in FIG. Is electrically connected to the ABS computer 30, and a control circuit such as a relay (not shown) energizes or de-energizes the solenoid of the solenoid valve 46 by a signal from the ABS computer 30.

As shown in FIG. 1, one end of a pipe 48 is connected to the solenoid valve 46, and the solenoid valve 46 is connected via the pipe 48 to one of a pair of rear wheels (not shown) of the vehicle. It is connected to an RR brake 50 as a brake provided corresponding to the right wheel.

Further, one end of a pipe 52 is connected to the pipe 48 in the middle thereof, and the solenoid valve 46 is connected to the solenoid valve 54 via the pipe 52.

The solenoid valve 54 has basically the same configuration as the above-described solenoid valve 46, and opens and closes the solenoid valve 54 by energizing and deenergizing the solenoid. Further, the solenoid valve 54 is also electrically connected to the ABS computer 30, and a control circuit (not shown) such as a relay turns on or off the solenoid of the solenoid valve 54 by a signal from the ABS computer 30.

The solenoid valve 54 is connected to the reservoir tank 42 via a pipe 56. When the solenoid valve 54 is open, the brake fluid supplied to the solenoid valve 54 via the pipe 52 is supplied to the pipe 56.
Through the reservoir tank 42.

On the other hand, as shown in FIG. 1, one end of a pipe 62 is connected to the master cylinder 12. Piping 62
Has one end communicating with the space between the primary piston 14 and the secondary piston 16 in the internal space of the master cylinder 12, and the other end communicating with the inside of a solenoid valve 64 as a valve which is a component of the present invention. are doing. The solenoid valve 64 has a solenoid, and is configured to open and close the valve by energization and de-energization accompanying energization and de-energization of the solenoid. As shown in FIG. 2, the solenoid valve 64 is electrically connected to the ABS computer 30 as control means. A control circuit (not shown) such as a relay is connected to the solenoid valve 6 by a signal from the ABS computer 30.
The solenoid 4 is energized or de-energized.

As shown in FIG. 1, one end of a pipe 66 is connected to the solenoid valve 64, and the solenoid valve 64 is connected via the pipe 66 to the right side of a pair of front wheels (not shown) of the vehicle. Are connected to an RF brake 68 as a brake provided corresponding to the wheels of the vehicle.

Further, as shown in FIG.
One end of a pipe 70 is connected on the way, and the solenoid valve 64 is connected to the solenoid valve 72 via the pipe 70.

The solenoid valve 72 has basically the same configuration as the above-described solenoid valve 64, and opens and closes the solenoid valve 72 by energizing and deactivating the solenoid. The solenoid valve 72 is also electrically connected to the ABS computer 30, and a control circuit (not shown) such as a relay turns on or off the solenoid of the solenoid valve 72 by a signal from the ABS computer 30.

The solenoid valve 72 is connected to a reservoir tank 76 via a pipe 74. When the solenoid valve 72 is open, the brake fluid supplied to the solenoid valve 72 via the pipe 70 is supplied to the pipe 74.
Through the reservoir tank 76.

On the other hand, as shown in FIG.
Communicates with one end of the pipe 78 in the middle thereof.
8 is connected to a solenoid valve 80 as a valve which is a constituent element of the present invention. The solenoid valve 80 has a solenoid similarly to the solenoid valve 64, and is configured to open and close the valve by excitation and de-energization accompanying energization and de-energization of the solenoid. As shown in FIG. Is electrically connected to the ABS computer 30, and a control circuit such as a relay (not shown) energizes or de-energizes the solenoid of the solenoid valve 80 by a signal from the ABS computer 30.

As shown in FIG. 1, one end of a pipe 82 is connected to the solenoid valve 80, and the solenoid valve 80 is connected to the solenoid valve 80 via the pipe 82, of a pair of rear wheels (not shown) of the vehicle. It is connected to an LR brake 84 as a brake provided corresponding to the left wheel.
Further, one end of a pipe 86 is connected in the middle of the pipe 82, and the solenoid valve 80 is connected to a solenoid valve 88 via the pipe 86.

The solenoid valve 88 has basically the same structure as the above-described solenoid valve 80, and opens and closes the solenoid valve 88 by energizing and deenergizing the solenoid. The solenoid valve 88 is also electrically connected to the ABS computer 30, and a control circuit (not shown) such as a relay turns on or off the solenoid of the solenoid valve 88 by a signal from the ABS computer 30.

The solenoid valve 88 is connected to the reservoir tank 42 via a pipe 90. When the solenoid valve 88 is open, the brake fluid supplied to the solenoid valve 88 via the pipe 86 is supplied to the pipe 90.
Through the reservoir tank 42.

As described above, the braking device 10 includes the plurality of solenoid valves 28 to 88, and a sensor group 92 (FIG. 2) including various sensors for detecting the rotation speed of each wheel, the traveling speed of the vehicle, and the like. AB) based on the signal from
A brake device that employs a so-called anti-lock brake system that opens and closes a plurality of solenoid valves 28 to 88 appropriately according to a signal from the S computer 30 to thereby prevent locking of each wheel during a braking operation during traveling. Has become.

By the way, as shown in FIG.
An orifice 102 is provided in 2. As shown in FIG. 3, the orifice 102 partially reduces the cross-sectional area of the flow path of the pipe 32, and when the brake fluid passes through the orifice 102, the orifice 102 becomes a resistance, and the orifice 102 is smaller than the orifice 102. On the upstream side (that is, on the master cylinder 12 side), the brake fluid is compressed and the fluid pressure rises.

The orifice 102 of the pipe 32 and the LF
A pressure sensor 104 as a liquid pressure measuring means is provided between the brake and the brake 34, and the pressure of the brake fluid flowing in the pipe 32 is detected by the pressure sensor 104.

As shown in FIG. 1, the pressure-sensitive sensor 104
Is electrically connected to the ABS computer 30 described above, and sends a predetermined signal to the ABS computer 30 when the hydraulic pressure of the brake fluid flowing in the pipe 32 is detected.

On the other hand, the pipe 48 is provided with an orifice 106. Although not shown, the orifice 10
6 also partially reduces the cross-sectional area of the flow path of the pipe 48 in the same manner as the orifice 102. When the brake fluid passes through the orifice 106, the orifice 106 becomes a resistance, and the upstream side of the orifice 106 ( That is, the brake fluid is compressed by the master cylinder 12) to increase the fluid pressure.

The orifice 106 of the pipe 48 and the RR
A pressure sensor 108 as a fluid pressure measuring means is provided between the brake 50 and the pressure sensor 108 to detect the fluid pressure of the brake fluid flowing in the pipe 48 between the orifice 106 and the RR brake 50.

As shown in FIG.
Is electrically connected to the above-described ABS computer 30, and when detecting an increase in the hydraulic pressure of the brake fluid flowing in the pipe 48, outputs a predetermined signal to the ABS computer 3.
It is sent to 0.

Further, as shown in FIG.
Is provided with an orifice 110. Although not particularly shown, the orifice 110 also partially reduces the cross-sectional area of the flow path of the pipe 66 similarly to the orifice 102, and when the brake fluid passes through the orifice 110,
The orifice 110 acts as a resistor, and compresses the brake fluid upstream of the orifice 110 (that is, on the master cylinder 12 side) to increase the fluid pressure.

The orifice 110 of the pipe 66 and the RF
A pressure sensor 112 as a fluid pressure measuring means is provided between the brake 68 and the fluid pressure of the brake fluid flowing in the pipe 66 between the orifice 110 and the RF brake 68.

As shown in FIG. 2, the pressure-sensitive sensor 112
Is electrically connected to the above-described ABS computer 30, and when detecting an increase in the hydraulic pressure of the brake fluid flowing in the pipe 66, sends a predetermined signal to the ABS computer 3.
It is sent to 0.

Further, as shown in FIG.
Is provided with an orifice 114. Although not particularly shown, the orifice 114 also partially reduces the cross-sectional area of the flow path of the pipe 82 similarly to the orifice 102, and when the brake fluid passes through the orifice 114,
The orifice 114 becomes a resistance, and compresses the brake fluid upstream of the orifice 114 (that is, the master cylinder 12 side) to increase the fluid pressure.

The orifice 114 of the pipe 82 and the LR
A pressure sensor 116 as a fluid pressure measuring means is provided between the brake 84 and the pressure sensor 116 and detects the fluid pressure of the brake fluid flowing in the pipe 82 between the orifice 114 and the LR brake 84.

As shown in FIG.
Is electrically connected to the ABS computer 30 described above, and when detecting an increase in the hydraulic pressure of the brake fluid flowing in the pipe 82, outputs a predetermined signal to the ABS computer 3.
It is sent to 0.

Next, a method of determining a failure of the braking device 10 according to one embodiment of the present invention will be described through the description of the operation and effects of the present embodiment.

In the braking device 10 having the above-described structure, when the brake pedal 22 is depressed to move the push rod 18 to the bottom of the master cylinder 12, the secondary piston 16 is pressed by the push rod 18 and the bottom of the master cylinder 12 is moved. The brake fluid between the secondary piston 16 and the primary piston 14 in the internal space of the master cylinder 12 is thereby compressed,
The hydraulic pressure is increased. The brake fluid in the space between the secondary piston 16 and the primary piston 14 whose fluid pressure has been increased is supplied to a solenoid valve 64 via a pipe 62. At this time, if the solenoid valve 64 is in the open state, the brake fluid is supplied to the solenoid valve 64.
Is sent to the RF brake 68 via the pipe 66, and the RF brake 68 is operated by the hydraulic pressure of the brake fluid.

The brake fluid supplied to the pipe 62 is sent to the solenoid valve 64 and also to the pipe 78, and is supplied to the solenoid valve 80 via the pipe 78. At this time, if the solenoid valve 80 is in the open state, the brake fluid is sent from the solenoid valve 80 to the LR brake 84 via the pipe 82, and the LR brake 84 is operated by the hydraulic pressure of the brake fluid.

On the other hand, when the hydraulic pressure of the brake fluid between the secondary piston 16 and the primary piston 14 is increased by sliding the secondary piston 16 to the bottom side of the master cylinder 12, the brake fluid is supplied to the pipe 62. At the same time, the primary piston 14 is slid toward the bottom of the master cylinder 12 by being pressed by the increased hydraulic pressure of the brake fluid. Thereby, the primary piston 1
The brake fluid between the cylinder 4 and the bottom of the master cylinder 12 is compressed, the hydraulic pressure is increased, and the brake fluid is
Is supplied to the solenoid valve 28 through At this time, if the solenoid valve 28 is in the open state, the brake fluid is supplied from the solenoid valve 28 to the LF through the pipe 32.
The LF brake 34 is sent to the brake 34 and operates with the hydraulic pressure of the brake fluid.

The brake fluid supplied to the pipe 26 is sent to the solenoid valve 28 and also to the pipe 44, and is supplied to the solenoid valve 46 via the pipe 44. At this time, if the solenoid valve 46 is in the open state, the brake fluid is sent from the solenoid valve 46 to the RR brake 50 via the pipe 48, and the RR brake 50 is operated by the hydraulic pressure of the brake fluid.

As described above, normally, the brake pedal 22
Step on the LF brake 34, RR brake 50,
The brake fluid is supplied to all of the RF brake 68 and the LR brake 84, and the LF brake 34, the RR brake 50,
All of the RF brake 68 and the LR brake 84 operate.

As described above, the main braking device 10
Adopts a so-called antilock brake system including a plurality of solenoid valves 28 to 88, various sensor groups 92, and an ABS computer 30. Since the anti-lock brake system is a well-known technology, a detailed description thereof will be omitted here. If the ABS computer 30 determines that the rotation of the wheels has stopped, although the vehicle itself is moving, A
The BS computer 30 includes solenoid valves 28 to 88
And a relay that electrically connects each of them to a battery mounted on the vehicle is controlled to open and close the solenoid valves 28 to 88 appropriately, thereby preventing the wheels from being locked during traveling.

By the way, if the orifice 1 of the pipe 32 is
02 between the LF brake 34, between the orifice 106 of the pipe 48 and the RR brake 50, between the orifice 110 of the pipe 66 and the RF brake 68, and between the orifice 114 of the pipe 82 and the LR brake 84. For example, the orifice 102 of the pipe 32 and the LF brake 34
If the brake pedal 22 is depressed and the LF brake 34, the RR brake 50, the RF brake 68, and the LR brake 84 are actuated in a state in which the brake fluid leaks between Since the fluid leaks, no brake fluid is supplied to the LF brake 34, and the LF brake 34 does not operate.

Here, in the present braking device 10, the orifices 102, 106, 110, and 114 are respectively connected to the pipe 32,
48, 66, and 82, the passage resistance of each of the orifices 102 to 114 causes the pipe 48 to be closer to the master cylinder 12 than the orifice 106, the pipe 66 to be closer to the master cylinder 12 than the orifice 110, and the pipe 8
The brake fluid is compressed not only on the master cylinder 12 side than the second orifice 114 but also on the upstream side of the orifice 102 in the pipe 32, and the hydraulic pressure of the brake fluid increases on the upstream side of the orifice 102. For this reason, the pipe 32
Pipe 4
At 8, 66 and 82, the hydraulic pressure of the brake fluid increases.

At this time, on the downstream side of each of the orifices 106 to 114 of each of the pipes 48, 66, and 82, an increase in the pressure of the brake fluid flowing through the pressure-sensitive sensors 108, 112, and 116 is detected. I do. However, at this time, since the brake fluid leaks from the pipe 32, the fluid pressure of the brake fluid does not increase downstream of the orifice 102 of the pipe 32, and therefore, only the pressure sensor 104 has the brake fluid. Does not detect a rise in fluid pressure.

Pressure sensors 104, 108, 112, 11
In the ABS computer 30 electrically connected to the brake fluid 6, although the pressure-sensitive sensors 108, 112, and 116 detect an increase in the brake fluid pressure, the pressure-sensitive sensor 104 detects the brake fluid pressure. Is not detected, it is determined that the brake fluid is leaking in the pipe 32. The ABS computer 30 that has determined the leakage of the brake fluid in the pipe 32 controls a relay or the like corresponding to the solenoid valve 28, closes the solenoid valve 28, and stops the supply of the brake fluid downstream of the solenoid valve 28. I do.

As a result, unlike the hydraulic pressure that has been reduced due to the effect of the brake fluid leaking from the pipe 32, the brake fluid that has been further boosted is supplied to the RR brake 50, the RF brake 68, and the LR brake 84.

As described above, the orifice 102 of the pipe 32 and the LF
The operation and effect of the present embodiment have been described on the assumption that the brake fluid leaks from the brake 34, but the orifice 102 of the pipe 32 and the LF brake 34
Between the orifice 106 of the pipe 48 and the RR brake 5
0, between the orifice 110 of the pipe 66 and the RF brake 68, and between the orifice 114 of the pipe 82 and the LR brake 84, and if there is no liquid leakage otherwise, The same operation as the above-described operation is performed, and the solenoid valve (that is, any one of the solenoid valves 28, 46, 64, and 80) corresponding to the one of the pipes 32, 48, 66, and 82 in which the liquid leak has occurred is set. A brake (ie, LF) corresponding to one of the pipes 32, 48, 66, 82 which is closed and in which no liquid leakage occurs.
Any of the brakes 34, 50, 68, 84) is supplied with the boosted brake fluid to operate.

Here, in a so-called tandem master cylinder such as the master cylinder 12 of the brake system 10, even if the liquid leaks as described above, the master cylinder 12 has an inner space. To the space between the primary piston 14 and the bottom of the master cylinder 12 and the space between the primary piston 14 and the secondary piston 16 that are not in communication with the leaked pipe,
Although the brake fluid is supplied to operate the brake corresponding to the pipe, as described in the item of the problem to be solved by the invention, the primary piston 14 and the secondary piston 16 slide sufficiently to Only after the supply of brake fluid to the leaked pipe has been stopped
Brake fluid supplied to the pipe on the side where no fluid leakage occurs is not sufficiently boosted.

On the other hand, in the present braking device 10, if the brake fluid is supplied to each of the pipes 32, 48, 66, and 82 by depressing the brake pedal 22, the AB
Since the S computer 30 closes the solenoid valve corresponding to the leaked pipe among the pipes 26, 46, 64, and 80, the LF brake 34, the RR brake 50,
Of the RF brake 68 and the LR brake 84, a sufficiently pressurized brake fluid can be supplied very quickly to the pipe on the side where no fluid leakage occurs.

Further, when compared with a braking device employing a general anti-lock brake system, the configuration specifically used for the main braking device 10 is the orifices 102 to 114 and the pressure-sensitive sensors 104 to 116, so that it is inexpensive. The above effects can be obtained at a low cost.

In the present embodiment, the ABS computer 30 closes the solenoid valve corresponding to the leaked pipe among the pipes 26, 46, 64, and 80. For example, FIG. A solenoid valve having the same configuration as the solenoid valve 28 and the like is provided in a portion of the pipe 26 indicated by an arrow A and a portion of the pipe 62 indicated by an arrow B, and the ABS computer 30 detects a liquid leak among these solenoid valves. It is good also as a structure which closes the solenoid valve corresponding to the piping which generated the. However, in this embodiment, since the solenoid valve required for the antilock brake system can be used as it is, the pipe 26 shown in FIG.
The cost can be reduced as compared with a configuration in which a solenoid valve is provided at a portion indicated by arrow A of FIG.

Further, even if the braking device does not employ the above-described anti-lock brake system, an orifice having the same structure as the orifice 102 and the like and a pressure sensor 104 and the like provided in the pipe connecting the master cylinder and each brake. A pressure sensor having the same configuration and a solenoid valve having the same configuration as the solenoid valve 28 are provided in the piping corresponding to each brake, and it is determined whether or not these pressure sensors have detected an increase in hydraulic pressure. If one of the pressure sensors detects an increase in brake fluid pressure and the other pressure sensors do not detect an increase in brake fluid pressure, then no increase in fluid pressure is detected. If the control means for closing the solenoid valve of the pipe corresponding to the pressure-sensitive sensor is provided, the same effect as the above-described effect can be obtained. However, as described above, in the present embodiment, since the solenoid valve is also required for the antilock brake system, considering that the solenoid valve can be used as it is, the present embodiment has a lower cost. The rise can be suppressed.

[0087]

As described above, according to the first and third aspects of the present invention, it is possible to detect a pipe in which fluid leakage has occurred immediately regardless of the distribution state of the brake fluid in the master cylinder. In addition, since it is only necessary to provide an orifice and a hydraulic pressure measuring means for measuring the hydraulic pressure in each pipe, the cost can be reduced.

According to the second and fourth aspects of the present invention, not only the effects of the first and fourth aspects of the present invention can be obtained, but also the liquid leakage immediately after the detection of the liquid leakage from the piping. Since the supply of the brake fluid to the pipe in which the liquid leakage has occurred can be stopped, the brake of the pipe on the side where no liquid leakage has occurred can be quickly operated.

Further, according to the present invention described in claim 5, not only the effects of the present invention described in claim 3 or claim 4 can be obtained, but also the first and second pistons can be sufficiently provided even in a so-called tandem master cylinder. It is possible to detect in which pipe a liquid leak has occurred earlier than when the liquid is moved to the bottom side of the master cylinder.

In the present invention described in claim 6, not only the effects of the present invention described in claim 4 or 5 are obtained, but also valves and control means used in a so-called antilock brake system are used. Therefore, the present invention can be realized at a lower cost, and can be realized by a simple design change for a vehicle employing the antilock brake system.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a system of a braking device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a control system of a system of the braking device according to the embodiment of the present invention.

FIG. 3 is a sectional view showing a configuration of an orifice.

[Explanation of symbols]

 Reference Signs List 10 braking device 12 master cylinder 14 primary piston (first piston) 16 secondary piston (second piston) 28 solenoid valve (valve) 30 ABS computer (control means) 32 piping 34 LF brake (brake) 46 solenoid valve (valve) 48 Piping 50 RR brake (brake) 64 Solenoid valve (valve) 66 Piping 68 RF brake (brake) 80 Solenoid valve (valve) 82 Piping 84 LR brake (brake) 92 Sensor group 102 Orifice 104 Pressure sensitive sensor (liquid pressure measuring means) 106 Orifice 108 Pressure-sensitive sensor (fluid pressure measuring means) 110 Orifice 112 Pressure-sensitive sensor (fluid pressure measuring means) 114 Orifice 116 Pressure-sensitive sensor (fluid pressure measuring means)

Claims (6)

[Claims] 1. A braking device for distributing brake fluid pressurized in the same master cylinder to a plurality of pipes and operating a brake connected to each of the plurality of pipes. A brake device failure determination method for determining the brake fluid leakage that has occurred in, wherein an orifice is provided in each of the plurality of pipes, and the brake fluid supplied to each of the plurality of pipes from the master cylinder is provided. While increasing the pressure between the master cylinder and the orifice, measuring the pressure of the brake fluid flowing between the orifice and the brake at each of the plurality of pipes, and measuring the hydraulic pressure of the orifice at any of the plurality of pipes When the increase in the hydraulic pressure is not measured in a pipe other than the pipe in which the increase in the hydraulic pressure is measured while the increase in the hydraulic pressure is measured between the brake and the brake. In this case, it is determined that the brake fluid has leaked from a pipe in which the increase in the hydraulic pressure has not been measured. 2. A valve is provided in each of the plurality of pipes between the orifice and the master cylinder, and a rise in the hydraulic pressure is measured in any of the plurality of pipes, and the rise in the hydraulic pressure is measured. 2. The braking device according to claim 1, wherein when the rise in the hydraulic pressure is not measured in a pipe other than the measured pipe, a valve corresponding to the pipe in which the rise in the hydraulic pressure is not measured is closed. Failure determination method. 3. A master cylinder having a bottomed cylindrical shape, a plurality of pipes having one end connected to the master cylinder, and a brake fluid boosted inside the master cylinder being distributed and supplied, and each of the pipes A plurality of brakes provided corresponding to the other end of the brake fluid and operated by the hydraulic pressure of the brake fluid supplied from the master cylinder; and a plurality of brakes provided on each of the plurality of pipes and supplied to the brake fluid supplied from the master cylinder. A plurality of orifices that provide resistance and increase the hydraulic pressure of the brake fluid between the master cylinder and the plurality of orifices provided in each of the plurality of pipes and the plurality of pipes between the orifice and the brake; A hydraulic pressure measuring means for measuring a hydraulic pressure of the brake fluid flowing through each of the brake fluids. 4. A plurality of valves provided in each of the plurality of pipes and configured to open and close the corresponding pipe between the orifice and the master cylinder, and based on a hydraulic pressure measurement result from the hydraulic pressure measuring means. The braking device according to claim 3, further comprising: control means for opening and closing the plurality of valves. 5. A first piston provided inside the master cylinder, and a second piston provided on a side opposite to a bottom of the master cylinder via the first piston. Any one of the pipes communicates between the first piston and the master cylinder in the internal space of the master cylinder, and the first piston and the master cylinder of the plurality of pipes communicate with each other. A pipe other than a pipe communicating with the internal space of the master cylinder between the first piston and the second piston is communicated with an internal space of the master cylinder between the first piston and the second piston. Item 5. The braking device according to Item 4. 6. The control device according to claim 1, wherein the control unit controls the brake during traveling by opening and closing the valve based on a signal from a sensor group that detects a state of each part of the vehicle during traveling. The braking device according to claim 4 or 5.