JP2015231794A - Air-bleeding method for vehicular brake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent invasion of air into a master cylinder side by bleeding air from a component downstream of the master cylinder when replacing the component.SOLUTION: An instruction device for externally transmitting a control command to an ECU 101 is connected to a vehicle. Operating the instruction device, a worker causes the ECU 101 to control so as to close normal-open master cut valve 60a and master cut valve 60b (S1). Then the worker replaces a necessary component among components disposed downstream of the master cut valves 60a, 60b, that is, downstream of a brake fluid, such as a slave cylinder 16 (S2). Then, while the slave cylinder 16 is caused to perform a stroke operation by the transmission of a command from the instruction device to the ECU 101, the worker bleeds air in the downstream of the master cut valves 60a, 60b (S3).

Description

  The present invention relates to an air bleeding method for a vehicle braking system.

For example, as shown in Patent Document 1, in response to a driver's operation of a brake pedal, a slave cylinder (motor cylinder) is driven by a motor to generate hydraulic pressure (hydraulic pressure), thereby generating a vehicle friction braking force. So-called by-wire brakes are known. Even in the by-wire brake, a master cylinder that generates hydraulic pressure in response to the driver's operation of the brake pedal is provided and hydraulically connected to the slave cylinder arranged downstream of the brake fluid flow. Communicate.
In such a by-wire brake, it may be necessary to replace parts downstream of the master cylinder, such as a slave cylinder.

JP 2013-112038 A

However, in a by-wire brake, when a part downstream of the master cylinder, such as a slave cylinder, is replaced, there is no brake fluid in the new part, that is, air is contained. Therefore, there is a problem that air enters the interior of the master cylinder or the like on the upstream side of the component.
An object of the present invention is to prevent the air from entering the master cylinder side by appropriately bleeding the parts even when the parts downstream from the master cylinder are replaced.

According to one aspect of the present invention, a master cylinder that generates hydraulic pressure by operating a brake pedal and a downstream side of the master cylinder communicate with each other, and the hydraulic pressure is increased by driving an electric actuator according to the operation of the brake pedal. An air venting method for a vehicle braking system, comprising: an electric hydraulic pressure generating unit to be generated; and a normally open valve that opens and closes a communication path for brake fluid between the master cylinder and the electric hydraulic pressure generating unit. A first step of closing the normally open valve via a command generated by a predetermined operation; and after the first step, the downstream side of the normally open valve while maintaining the normally open valve closed state And a second step of releasing the air of the vehicle.
According to the present invention, after the normally open valve between the master cylinder and the electric hydraulic pressure generating unit is closed, the air is released from the downstream side of the normally open valve while the closed state is maintained. Therefore, when replacing a part downstream of the master cylinder, even if the part is vented, it is possible to prevent air from entering the master cylinder.

In the above case, a third step of replacing the part on the downstream side of the brake fluid with respect to the normally open valve may be provided after the first step and before the second step.
According to the present invention, when a part downstream from the master cylinder is replaced, the part can be vented to prevent air from entering the master cylinder.

Further, in the above case, in the second step, the electrohydraulic generator is controlled to operate at a preset operating amount so that the air is released according to the operating amount. Good.
According to the present invention, air bleeding can be performed by controlling and operating the electrical hydraulic pressure generating unit, so that the air bleeding operation is facilitated.

  Even when a part downstream of the master cylinder is replaced, the part can be appropriately vented to prevent air from entering the master cylinder.

It is explanatory drawing of the braking system of the vehicle concerning one Embodiment of this invention. 1 is a block diagram of a control system centered on an ECU of a vehicle braking system according to an embodiment of the present invention. FIG. It is a flowchart explaining the air bleeding method of the braking system of the vehicle concerning one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory diagram of a vehicle braking system 10 according to an embodiment of the present invention. The vehicle braking system 10 is a device for generating a friction braking force in the vehicle. Specifically, the vehicle braking system 10 includes a by-wire brake system.

That is, the vehicle braking system 10 responds to the brake fluid pressure generated in the input device 14 including the master cylinder 34 and the like that converts the pedaling force input by the driver by the operation of the brake pedal 12 into the brake fluid pressure. Or a motor cylinder (slave cylinder) 16 that generates a brake fluid pressure regardless of the brake fluid pressure, a vehicle behavior stabilization device 18, and disc brake mechanisms 30a to 30d. The slave cylinder 16 serving as an electric hydraulic pressure generating unit includes first and second slave pistons 77a and 77b that receive a driving force of a motor 72 serving as an electric actuator and generate brake hydraulic pressure.
Note that the piping tubes 22a to 22f are provided with brake fluid pressure sensors Pm, Pp, and Ph that detect the brake fluid pressure of each part.

  The slave cylinder 16 includes a wheel cylinder 32FR that generates friction braking force by hydraulic pressure by a disc brake mechanism 30a provided on the right front wheel of the vehicle, and a hydraulic brake that controls the disc brake mechanism 30b provided on the left rear wheel. The wheel cylinder 32RL for generating power, the wheel cylinder 32RR for generating friction braking force by hydraulic pressure on the disc brake mechanism 30c provided on the right rear wheel, and the disc brake mechanism 30d provided on left front wheel by the hydraulic pressure A wheel cylinder 32FL that generates a braking force is connected.

The vehicle behavior stabilization device 18 includes a pump 73 that supplies brake fluid, a motor M that drives the pump 73, and various valves illustrated in FIG. This is a device for stabilizing the behavior of the vehicle by individually supplying hydraulic pressure to the cylinders 32FR, 32RL, 32RR, and 32FL. For example, an ABS (Antilock Brake System) is also operated by the vehicle behavior stabilization device 18.
In addition, an ECU (Electronic Control Unit) 101 for controlling a by-wire brake system mainly including the input device 14 and the slave cylinder 16 of the vehicle braking system 10 is provided in the housing of the input device 14. It has been.

  Next, the basic operation of the vehicle braking system 10 will be described. In the vehicle braking system 10, when the driver steps on the brake pedal 12 during normal operation of the ECU 101 that controls the by-wire brake system such as the slave cylinder 16, a so-called by-wire brake system is activated. become. Specifically, in the vehicle braking system 10 during normal operation, when the driver steps on the brake pedal 12, the operation amount and operation speed of the brake pedal 12 are detected by a brake pedal stroke sensor (not shown). In the state where the first shutoff valve 60a and the second shutoff valve 60b shut off the communication between the master cylinder 34 and the disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR, 32FL) that brake the wheels, the slave cylinder 16 However, the brake fluid pressure generated by driving the motor 72 is used to actuate the disc brake mechanisms 30a-30d (wheel cylinders 32FR, 32RL, 32RR, 32FL) to brake each wheel. The first cutoff valve 60a and the second cutoff valve 60b are electromagnetic valves that are normally open valves, and are hereinafter also referred to as a master cut valve 60a and a master cut valve 60b.

  Further, during normal operation, the first shut-off valve 60a and the second shut-off valve 60b are shut off, while the third shut-off valve 62 is opened, and the brake fluid is supplied from the master cylinder 34 to the stroke simulator (pedal force simulator) 64. Even when the first shut-off valve 60a and the second shut-off valve 60b are shut off, the brake fluid moves, and a stroke occurs when the brake pedal 12 is operated, and a pedal reaction force is generated. The third shut-off valve 62 may be provided in the system on the piping tube 22a side.

On the other hand, in the vehicle braking system 10, when the driver steps on the brake pedal 12 in an abnormal state in which the slave cylinder 16 or the like is inoperative, the existing hydraulic brake system becomes active. Specifically, in the vehicle braking system 10 at the time of abnormality, when the driver steps on the brake pedal 12, the first cutoff valve 60a and the second cutoff valve 60b are opened, and the third cutoff valve 62 is set. Is closed, the brake hydraulic pressure generated in the master cylinder 34 is transmitted to the disc brake mechanisms 30a to 30d (the wheel cylinders 32FR, 32RL, 32RR, and 32FL), and the disc brake mechanisms 30a to 30d (the wheel cylinders 32FR, 32RL, 32RR, 32FL) are actuated to brake each wheel.
Since other configurations and operations of the input device 14, the slave cylinder 16, the vehicle behavior stabilization device 18, and the like are well known, detailed description thereof is omitted.

  FIG. 2 is a block diagram of a control system of the vehicle braking system 10 with the ECU 101 as the center. The ECU (so-called ESB-ECU) 101 centrally controls the input device 14, the slave cylinder 16, and the like. In particular, the ECU 101 includes a valve control unit 111 that controls the master cut valve 60a and the master cut valve 60b, and a valve drive circuit 112 that opens and closes the master cut valve 60a and the master cut valve 60b based on the control of the valve control unit 111. I have. The ECU 101 also includes a cylinder control unit 121 that controls a motor 72 that drives the slave cylinder 16, and a motor drive circuit 122 that drives the motor 72 based on the control of the cylinder control unit 121.

By the way, in the vehicle braking system 10 configured as described above, the slave cylinder 16, the vehicle behavior stabilization device 18, the wheel cylinders 32FR, 32RL, which are components located downstream of the master cylinder 34 in the flow of the brake fluid. 32RR, 32FL, etc. may be exchanged.
For example, when the slave cylinder 16 is replaced with a new one, air exists in the flow path or space in which the brake fluid in the new slave cylinder 16 flows. Therefore, if the slave cylinder 16 is replaced with a new one as it is, the air in the new slave cylinder 16 will flow into the master cylinder 34 which is further upstream of the brake fluid flow. is there. The same problem also occurs when the vehicle behavior stabilization device 18 and the wheel cylinders 32FR, 32RL, 32RR, 32FL are replaced with new ones.

Therefore, an air bleeding method of the vehicle braking system for solving such a problem of air inflow to the slave cylinder 16 in the case of parts replacement will be described below.
In the air bleeding method of this vehicle braking system, an indicating device 201 shown in FIG. 2 is used. The instruction device 201 is prepared in a vehicle repair shop or the like, and is a device separate from the vehicle that is used when performing the above-described part replacement work. The instruction device 201 is connected to the vehicle so as to be communicable with the ECU 101 only when used. That is, for example, the instruction device 201 can communicate with a CAN (Controller Area Network) mounted on the vehicle, and thus can communicate with the ECU 101 via the CAN. The instruction device 201 transmits a control signal (command) for controlling the master cut valve 60a and the master cut valve 60b to the ECU 101, and performs control via the ECU 101 so as to close the master cut valve 60a and the master cut valve 60b. A valve closing instruction unit 211 is provided. In addition, the instruction device 201 transmits a control signal (command) for controlling the motor 72 and the like of the slave cylinder 16 to the ECU 101, and a cylinder operation instruction unit that is controlled via the ECU 101 so as to cause the slave cylinder 16 to perform an operation described later. 212 is provided.

The air bleeding method of the vehicle braking system according to the present embodiment is executed after the pointing device 201 is connected to the vehicle so as to be communicable with the ECU 101. Below, the procedure is demonstrated with reference to the flowchart of FIG.
First, the operator operates the indicating device 201, transmits a command to the ECU 101 by the valve closing instruction unit 211, and is controlled by the valve control unit 111 of the ECU 101, so that the master cut valve 60a and the master cut valve which are normally open valves are used. 60b is closed (S1) (first step).

Next, the operator can use components located downstream of the brake fluid from the master cut valve 60a and the master cut valve 60b (also downstream from the master cylinder 34), such as the slave cylinder 16 and the vehicle behavior stabilization device 18. Of the wheel cylinders 32FR, 32RL, 32RR, 32FL, etc., ones that need to be replaced are replaced (S2) (third step).
Thereafter, the operator performs an air bleeding operation on the downstream side of the brake fluid from the master cut valve 60a and the master cut valve 60b while maintaining the closed state of the master cut valve 60a and the master cut valve 60b.

For this work, the instruction device 201 is operated, the cylinder operation instruction unit 212 transmits a command to the ECU 101, the slave cylinder 16 (the motor 72 thereof) is controlled, and the slave cylinder 16 is operated with a preset operation amount. Accordingly, the air can be removed from the bleeder provided in the slave cylinder 16 and the bleeder provided in the wheel cylinders 32FR, 32RL, 32RR, and 32FL in accordance with the operation amount. That is, by transmitting a command from the pointing device 201 to the ECU 101, the worker performs a bleeding operation in accordance with the continuous stroke operation of the slave cylinder 16 (S3) (second step). In order to synchronize with the continuous stroke operation of the slave cylinder 16, a lamp is turned on by the pointing device 201 so that the operator can easily understand that the stroke operation of the slave cylinder 16 is being executed. May be. This completes the air bleeding operation.
In addition, as described above, after the air bleeding operation is sufficiently performed and the replacement parts on the downstream side of the master cut valve 60a and the master cut valve 60b are filled with the brake fluid, the master cut valve 60a and the master cut valve are filled. 60b is opened by the valve closing instruction unit 211 of the indicating device 201.

  According to the air bleeding method of the vehicle braking system of the present embodiment described above, the master cut valve 60a and the master cut valve 60b, which are normally open valves, are closed (S1), and necessary parts are replaced ( S2) The air venting operation is performed downstream of the master cut valve 60a and the master cut valve 60b (S3). Therefore, when replacing parts downstream of the master cylinder 34 (master cut valve 60a, master cut valve 60b), the part is bleed to prevent air from entering the master cylinder 34 side. be able to.

  Needless to say, the present invention is not limited to the above-described embodiment. For example, in the above example, the slave cylinder 16 (the motor 72 thereof) is driven by a command transmitted from the cylinder operation instruction unit 212 of the instruction device 201. However, the driving of the slave cylinder 16 can also be realized by the operator continuously depressing the brake pedal 12 and releasing the foot. Therefore, in S3, the stroke operation of the slave cylinder 16 may be performed without using the pointing device 201.

However, the operation of continuously driving the slave cylinder 16 by the operator repeating the operation of stepping on and releasing the brake pedal 12 is complicated.
That is, as described above, if the work of S3 is performed using the pointing device 201, the workability of the air bleeding work can be improved and the number of work steps can be reduced as compared with the case where the brake pedal 12 is manually operated. it can.

10 Brake System for Vehicle 12 Brake Pedal 16 Slave Cylinder (Electric Fluid Pressure Generator, Parts)
18 Vehicle behavior stabilization device (parts)
32FR, 32RL, 32RR, 32FL Wheel cylinder (parts)
34 Master cylinder 72 Motor (electric actuator)
S1 (first step)
S2 (third process)
S3 (2nd process)

Claims (3)

A master cylinder that generates hydraulic pressure by operating the brake pedal;
An electrical hydraulic pressure generator that is communicated downstream of the master cylinder and generates hydraulic pressure by driving an electrical actuator in response to an operation of the brake pedal;
A normally open valve that opens and closes the communication path of the brake fluid between the master cylinder and the electrical hydraulic pressure generator;
An air bleeding method for a vehicle braking system comprising:
A first step of closing the normally open valve via a command generated by a predetermined operation;
After the first step, a second step of performing air bleeding on the downstream side of the normally open valve while maintaining the closed state of the normally open valve;
An air bleeding method for a vehicle braking system, comprising:   2. The vehicle according to claim 1, further comprising a third step of exchanging the parts downstream of the brake fluid from the normally open valve after the first step and before the second step. Method of air release for braking system.   The said 2nd process performs the said air bleeding according to the said operation amount by controlling the said electrohydraulic pressure generation | occurrence | production part from the outside of a vehicle, and making it operate | move by the preset operation amount. 3. A method for bleeding air from a vehicle braking system according to 2.

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