JPH0568396B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a braking oil pressure holding system for a vehicle braking system, and more particularly to a braking oil pressure holding system that can smoothly start a stopped vehicle on an uphill road.

(Prior art) If a vehicle uses a dry clutch or an electromagnetic clutch as its clutch mechanism and is not equipped with a torque converter, when starting after stopping on an uphill road, the vehicle must be stopped by operating the hand brake with one hand. , the vehicle is started by operating the clutch pedal, engaging the clutch, depressing the accelerator pedal, and releasing the hand brake. Also, do not operate the vehicle's brakes using the hand brake, but stop the vehicle by depressing the brake pedal with your right foot, then depress the clutch pedal to select a gear in the transmission, and then gradually engage the clutch and press the right foot. There is also an operation method in which the clutch is engaged at the same time as the brake is released while the engine speed is increased while the accelerator pedal is used instead of the brake pedal to start the vehicle.

The former method is the one commonly used when driving, but if the timing of the hand brake, clutch pedal, and accelerator pedal is out of order, the vehicle will move backwards or the engine will stop, and the latter method is a method that requires extremely skill;
It is not easy to become proficient and start the vehicle smoothly.

In addition, in order to solve the above-mentioned problems, an electromagnetic check valve is installed in the middle of the braking oil piping from the master cylinder to the wheel cylinder, so that the braking force is maintained even when the brake pedal is released, and the braking force is maintained even when the brake pedal is released. When the pedal is depressed and the vehicle restarts, the electromagnetic check valve is released and the braking force of the vehicle is released when the clutch begins to engage. In this method of installing an electromagnetic check valve, a clutch stroke sensor installed in the clutch detects the point at which the clutch begins to engage and releases the electromagnetic check valve. If it leans toward the cut side, the vehicle will move backwards on a steep slope. In addition, if the setting at the above point is biased toward the engagement side of the clutch, the brake force will be released while the torque transmitted from the engine by the clutch is applied to the wheels, which may cause impact to the vehicle or brake force. If the brakes are weak, the vehicle will be moved with the brakes applied. Therefore, in order to correct these problems, the release of the electromagnetic check valve is selected and set at an appropriate time while balancing the above two factors.

(Problems with the prior art) In order to smoothly start the vehicle on an uphill road, the electromagnetic check valve is set to be released at an appropriate time as described above, but in general, the vehicle is started backwards on an uphill road. In many cases, driving operations are performed more carefully and gradually than when moving forward, and as a result, the electromagnetic check valve may operate early and the brake may be released too early.
In other words, when the accelerator pedal is not depressed enough, the engine's driving torque is not enough, and the clutch is not fully engaged, the electromagnetic check valve operates and the brakes are released, causing the vehicle to drive down a slope due to its weight. This results in a falling defect.

(Object of the Invention) The object of the present invention is to eliminate the above-mentioned conventional drawbacks and to provide a brake hydraulic pressure holding device that allows a vehicle to smoothly reverse and climb a slope without any problems even when reversing on an uphill road. be.

(Summary of the Invention) In order to achieve the above-mentioned objects of the present invention, a check valve is provided that retains the hydraulic pressure that activates the brake when the brake pedal is depressed, and a solenoid that is connected in parallel with the check valve and energizes the solenoid. The solenoid valve is normally closed during operation when the clutch is closed, and the brake hydraulic pressure holding device detects the movement of the clutch from disengagement to engagement and moves the solenoid valve from close to open. A first engagement position detection means detects the A setting position in the middle of the A setting position, and a second engagement position detection means detects the B setting position provided on the contact side of the A setting position detected by the first engagement position detection means. The solenoid valve is driven in the opening direction by the position detection of the first engagement position detection means when the vehicle starts moving forward, and the position of the second engagement position detection means is detected when the vehicle starts moving backward. Accordingly, there is provided a brake oil pressure holding device characterized by comprising a solenoid valve driving means for driving the solenoid valve in the opening direction.

(Example) Next, an example of the present invention will be described in detail using the drawings.

FIG. 1 is a block diagram showing a first embodiment of a brake oil pressure holding device according to the present invention.

In the figure, reference numeral 1 denotes a master cylinder which serves as a fluid driving means that is activated by pressing down on a brake pedal 9, and which pressure-feeds braking fluid to the wheel cylinder 2, which is a brake actuating means, via an electromagnetic check valve device 3. , which operates the vehicle's brake system. The electromagnetic check valve device 3 has two hydraulic routes, a check valve 4 and a solenoid valve 5.
is the suction core 7 that is activated by energizing the solenoid 6.
The return spring 5a (these are defined as electromagnetic valve driving means) opens and closes the hydraulic route from the wheel cylinder 2 back to the master cylinder 1. The attraction force of the solenoid 6 is controlled by a current from a battery 10 by a transistor TR provided in a control unit 8, which will be described later.

Reference numeral 11 indicates various detection devices installed in the vehicle, including a vehicle speed sensor, an accelerator pedal sensor, a clutch stroke sensor A, a clutch stroke sensor B, an engine rotation sensor,
There is a brake pedal switch, gear position switch, clutch switch, and selector position switch, which detect the vehicle speed, accelerator pedal, clutch stroke, engine rotation, brake pedal, gear position, clutch pedal, and selector lever. It is configured to send detection signals for each of these states to the control unit 8. When the detection signals sent out by the various detection devices 11 satisfy predetermined operating conditions, the control unit 8 issues a drive signal to the base terminal of the internal transistor TR to turn on the transistor TR.
Then, the solenoid 6 is energized to attract the suction core 7 and the solenoid valve 5 is operated to disconnect the hydraulic route. Therefore, the oil pressure of the wheel cylinder 2 is maintained, and the braking force is also maintained. Further, when the detection signal from the various detection signals 11 satisfies a predetermined operating condition other than the above, no signal is sent to the base terminal of the transistor TR, so the transistor
TR does not turn ON, so solenoid 6
The solenoid valve 5 opens the hydraulic route by the operation of the return spring 5a, the braking oil in the wheel cylinder 2 flows to the master cylinder 1, and the brake is released. That is, the solenoid valve 5 becomes a normally closed solenoid valve during operation.

Next, the clutch stroke sensor A and the clutch stroke sensor B included in the various detection devices 11 are detection devices (these clutch stroke sensor A and clutch stroke sensor B) that detect the state of the clutch stroke and issue respective detection signals as described above. (defined as first engagement position detection means and second engagement position detection means, respectively)
However, clutch stroke sensor A detects when the vehicle starts forward in the middle of a slope and climbs a slope.
This is a detection device that detects the clutch stroke A (this is defined as the A setting position) at the timing when the clutch starts to engage and transmits the engine's driving force, and the vehicle does not move backward even if the brake is released, and issues a signal. Also, clutch stroke sensor B
is the timing when the vehicle does not descend due to the driving force of the engine even if the brake is released at a point on the clutch engagement side than the clutch stroke sensor A when the vehicle starts backwards in the middle of a slope. The detection device is configured to detect B (this is defined as the B setting position) of the clutch stroke of the clutch stroke and generate a signal.

FIG. 2 is a curve diagram showing the relationship between the clutch stroke and the above-mentioned A and B.

Next, the operation of this embodiment having such a configuration will be explained with reference to the processing flow diagram shown in FIG. First, various detection devices 11 of the control unit 8
Among them, it is determined that the engine is rotating based on the detection signal from the engine rotation sensor, the detection signal from the selector position switch is outside the neutral range, and the detection signal from the gear position switch is in the gear position 1. , the vehicle is in second gear or reverse gear, the amount of accelerator pedal depression is zero according to the detection signal from the accelerator pedal sensor, the vehicle speed is zero according to the detection signal from the vehicle speed sensor, and the clutch is in an open state according to the detection signal from the clutch sensor. , and if the brake pedal is depressed by a detection signal from the brake pedal switch, the predetermined operating condition is met, so a drive signal is sent to the base of the transistor TR, and the transistor TR ON
shall be. And solenoid 6 has battery 10.
Since the current is applied, the suction core 7 is activated, and the solenoid valve is activated against the elastic force of the return spring 5a, thereby cutting off the return hydraulic route from the wheel cylinder 2. Therefore, when the brake pedal 9 is depressed, the brake fluid that is forced from the master cylinder 1 and flows into the wheel cylinder 2 via the electromagnetic check valve device 3 applies the brakes to the wheels, causing the check valve 4 and the electromagnetic valve to 5 prevents backflow to the master cylinder 1, so even when the brake pedal 9 is released, the brake hydraulic pressure is maintained in the wheel cylinder 2, and the vehicle remains stopped.

Next, when starting the vehicle uphill, the process moves to step a in the process flow diagram of FIG. If it is determined from the detection signal from the accelerator pedal sensor that the accelerator pedal is being depressed, step b is performed.
If the detection signal from the gear position switch is other than reverse in step b, the process advances to step c. And clutch stroke sensor A
When the above-mentioned detection signal detects the engaged state of A in the clutch stroke and issues a signal, the drive signal to the base of the transistor TR inside the control unit 8 is released, and therefore the solenoid 6
The energization is also cut off, and the solenoid valve 5 is released by the restoring force of the return spring 5a.

Therefore, the brake fluid that had been holding the brake oil pressure in the wheel cylinder 2 flows back to the master cylinder 1 via the released solenoid valve 5, so that the brake force on the wheels is released and the clutch is engaged at the same time. As mentioned above, since the state is the appropriate state A for forward movement, the driving torque of the engine can be sufficiently transmitted, making it possible to start smoothly on a slope.

If the detection signal from the gear position switch indicates reverse gear in step b, the process proceeds to step d, and then the detection signal from clutch stroke sensor B detects the engaged state of B in the clutch stroke and sends a signal. When this occurs, the drive signal to the base of the transistor TR is released and the solenoid valve 5 is released.

In this case, since the vehicle is climbing a hill in reverse, the clutch stroke is set in state B, which has a larger engagement amount than state A, as described above, so the driver gradually increases the driving operation to reverse. Even if you go uphill, it is possible to climb smoothly.

In addition, in the above embodiment, the case of forward and reverse is explained for starting on a slope, but for example, the engagement amount may be changed outside of clutch strokes A and B to provide forward and reverse for starting on a steep slope. As such, various modifications and applications are possible.

Further, in this embodiment, two types of clutch stroke sensors A and B are provided, but it is also possible to switch and set the operating conditions to two types, A and B, using one clutch stroke sensor. .

FIGS. 4 and 5 are block diagrams showing second and third embodiments of the present invention, and the same parts as those described above are given the same reference numerals, and the explanation thereof will be omitted.

These second and third embodiments both relate to a braking mechanism having a booster 12, and when the brake pedal 9 is depressed, the air tank 1 is
3 actuates the relay valve 14 via the valve 9a, and sends the pressurized air from the air tank 13 to the booster 12, thereby actuating the power piston 12a and increasing the pressure of the connected hydraulic piston 12b. When activated, braking oil is force-fed to the wheel cylinders 2 to brake the vehicle.

Therefore, as shown in FIG. 4, the electromagnetic check valve device 3 installed in the pipe connecting the relay valve 14 and the booster 12 is a solenoid valve that releases the pressure air sent to the booster 12. As explained in the first embodiment, the operating conditions can be set to a plurality of conditions, and smooth hill start is possible under these conditions.

FIG. 5 also shows an electromagnetic check valve device 3 installed in the brake oil passage between the booster 12 and the wheel cylinder 2.
However, the operation of releasing the hydraulic pressure of the solenoid valve is the same as in the first embodiment.

FIG. 6 is a configuration block diagram showing a fourth embodiment of the present invention, in which when the brake pedal 9 is depressed, the pressure of the air tank 13 operates the relay valve 14 through the valve 9a, and the air is released from the air tank 13. Pressure air is sent to the air cylinder 15 via the relay valve 14 to operate the air piston 16, and the cam 17 is operated to operate the brake shoe 1.
8 to brake the wheels. The electromagnetic check valve device 3 is disposed in the middle of the air passage between the relay valve 14 and the air cylinder 15.
The operating conditions for the solenoid valve provided in the electromagnetic check valve device 3 to release the pressure in the air cylinder 15 can be set to a plurality of conditions as described above. It is possible to start on a slope.

(Effects of the Invention) As described above in detail, the present invention sets the operating conditions of the solenoid valve that releases the braking hydraulic pressure of the wheel cylinder to at least a plurality of engagements of the clutch in order to smoothly start the vehicle on an uphill road. The clutch stroke sensor detects the clutch stroke sensor, and the settings are made to correspond to multiple different conditions, with multiple settings being made for forward and reverse travel, so you can start smoothly even when starting on a slope in any case. This makes it possible to prevent the engine from stopping and the vehicle from moving backwards. Therefore, the driver is less concerned about starting the vehicle, and can concentrate on driving safely with pedestrians and other vehicles.

In addition, the operating conditions of the electromagnetic valve are not only suitable for general forward and reverse starting on a slope, but can also be modified to suit, for example, starting on a steep slope, so smooth starting is possible in various cases.

[Brief explanation of the drawing]

FIG. 1 shows a first diagram of a brake hydraulic pressure holding device according to the present invention.
FIG. 2 is a curve diagram showing the relationship between the clutch stroke and strokes A and B, FIG. 3 is a processing flow diagram showing the processing of the embodiment configured in FIG. 1, and FIG. , FIG. 5, and FIG. 6 are block diagrams showing second, third, and fourth embodiments of the present invention. 1...Master cylinder, 2...Wheel cylinder, 3...Solenoid check valve device, 5...Solenoid valve, 8
... Control unit, 9 ... Brake pedal, 11
... Various detection devices.

Claims (1)

[Scope of Claims] 1. A check valve that maintains the hydraulic pressure that activates the brake when the brake pedal is depressed, and a normally closed type that is connected in parallel with the check valve and closed by the energization of a solenoid. In the brake hydraulic pressure holding device which operates the solenoid valve from close to open by detecting the movement of the clutch from disengagement to engagement, a first part detects the A setting position on the way from disengagement to engagement of the clutch. an engagement position detection means, a second engagement position detection means for detecting a B setting position provided on the tangent side of the A setting position detected by the first engagement position detection means; When the position of the first engagement position detection means is detected, the electromagnetic valve is driven in the opening direction, and when the vehicle is started in reverse, the electromagnetic valve is driven in the opening direction by the position detection of the second engagement position detection means. A brake hydraulic pressure holding device comprising: a valve drive means. 2. The brake oil pressure holding device according to claim 1, wherein air is used as the fluid of the fluid driving means. 3. The brake oil pressure holding device according to claim 1, wherein oil is used as the fluid of the fluid driving means. 4. The brake oil pressure holding device according to claim 1, wherein air and oil are used as the fluid of the fluid driving means.