JP3987696B2 - Slope start assist device - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention is used in an automobile equipped with a clutch pedal. In the present invention, when starting from a state where the vehicle stops on a slope, the brake is automatically held even when the driver removes his / her foot from the brake pedal, and the clutch pedal is released beyond a preset release point. The present invention relates to an improvement in a slope start assist device that automatically releases a brake when the vehicle starts. The present invention relates to an improvement for smoothly executing an operation for causing a vehicle to travel at a low speed while maintaining a clutch pedal in a half-clutch state with a left foot and changing a brake pedal or an accelerator pedal with a right foot.
[0002]
[Prior art]
When starting a car that has stopped on a hill road in the direction of climbing the hill, the driver applies brakes to the vehicle, applies braking force to the vehicle, steps on the clutch pedal, sets the transmission gear to the start gear, While reducing the stroke, loosen the brake and depress the accelerator pedal to increase the engine output. Such an operation is a basic procedure in a driving operation of an automobile having a clutch pedal, as a slope starting operation. In large vehicles such as trucks and buses, the operation varies greatly depending on the size of the cargo and the number of passengers, and it is easy to stop the engine or reverse the vehicle when starting a slope. As a device for assisting such a driving operation, a slope start assist device has come to be widely used (Japanese Patent Laid-Open Nos. 60-11719, 4-244462, etc.).
[0003]
In such a device, when the brake pressure exceeds a certain value due to the operation of the brake pedal and the vehicle speed becomes zero, if the clutch pedal is depressed deeply, the driver The brake pressure is automatically maintained even when the foot is released. In this state, if the transmission is engaged in the starting gear, when the clutch pedal is removed, when the clutch pedal stroke reaches a preset release point, the brake pressure that has been held is automatically Controlled to be released. Using this device, the driver does not need to use nerves to determine how much to operate the clutch stroke with the left foot, the timing for quickly switching the right foot from the brake pedal to the accelerator pedal, etc. become. Such a slope start assist device has been widely installed in trucks and other vehicles. And this device will be used not only when starting up a hill in an uphill direction but also for simplifying the procedure of driving operation in a scene where starting and stopping are repeated on a congested road. It was.
[0004]
Here, even if the brake pedal is released as described above, it is necessary to step on the clutch pedal at least to the release point of the brake pressure in order to start the operation to maintain the brake pressure. is there. In order to start the operation of maintaining the brake pressure, a device has been proposed for setting the stroke of the clutch pedal so that it must be stepped further deeper than the brake pressure release point (Japanese Patent Laid-Open No. Hei 1). No. 60455, Japanese Patent No. 2718037). In other words, an offset is provided between the brake pressure holding start point and the brake pressure release point, rather than being set at the same point of the clutch pedal stroke. Please refer to FIG. FIG. 3 will be described in more detail later.
[0005]
This device prevents the clutch from entering the half clutch state when the brake pressure is automatically maintained, that is, the braking force generated by maintaining the brake pressure is not reduced by the half clutch state. It is an excellent device that can be made. In addition, by providing this offset, the brake pressure is limited only when the clutch / pedal stroke is within the range of this offset in the case of slow speed driving on a congested road, garage entry operation of the vehicle, change of stop position, etc. There is an advantage that traveling by a half-clutch is possible without performing the holding operation.
[0006]
On the other hand, the slope start assisting device is designed so that the driver can adjust the brake pressure release point position by operation (Japanese Patent Laid-Open No. 8-111080). This allows the driver to adjust and set the release point at which the brake pressure is released to the deeper side or the shallower side of the clutch / pedal stroke. As a result, the driver can change the release point of the brake pressure according to the road surface condition, the load condition, the mechanical wear state of the clutch plate, or the driver's preference. A device that can change the release point by operation is very popular among users.
[0007]
[Problems to be solved by the invention]
By the way, the driver operates the brake pressure release point position as described above, and the technology for providing an offset in the clutch pedal stroke between the brake pressure holding start point and the brake pressure release point as described above. The technology that can be adjusted by is not in harmony with each other. If the driver adjusts the brake pressure release point position to the larger side of the clutch / pedal stroke and the offset becomes zero, the above-described slow speed operation cannot be performed. That is, if the vehicle is started using the slope start assist device and the vehicle is driven at a slow speed while the clutch is engaged and disengaged after starting the vehicle, the clutch pedal stroke reaches the brake pressure holding start point. In this case, if the brake pedal is operated at this time, the brake pressure is maintained as it is. Such a situation often occurs when the vehicle is repeatedly stopped and started using a slope start assist device on a congested road.
[0008]
Further, if the brake pressure release point position is adjusted beyond the position where the offset becomes zero and the clutch / pedal stroke is increased, the operation itself for maintaining the brake pressure does not work. In this case, the slope start assist device cannot be used effectively.
[0009]
When the driver changes the release point position of the brake pressure, keep the offset value as it is and change the brake pressure holding start point position with the change of the release point position. Although it is conceivable to configure the software, in this case, the brake pressure holding start position cannot be physically configured to move deeper than the deepest position of the clutch pedal stroke. Therefore, the range in which the release point position can be changed is narrowed by the offset, and the advantage that the release point position can be changed is substantially lost. In other words, if the clutch pedal stroke is offset between the brake pressure release point and the brake pressure holding start point, the brake pressure release point position can be changed by operation. The release point of the brake pressure cannot be changed over a wide range from the state where the clutch is connected to the state where the clutch is disengaged.
[0010]
The present invention has been made against such a background, and the vehicle can be operated without providing an offset with respect to the stroke of the clutch pedal between the brake pressure holding start point and the brake pressure release point. An object of the present invention is to provide a slope start assist device capable of traveling at a low speed in a half-clutch state. SUMMARY OF THE INVENTION An object of the present invention is to provide a slope start assist device that can change a brake pressure release point in a wide range by a driver's operation.
[0011]
[Means for Solving the Problems]
When the vehicle is started using the slope start assist device and the vehicle is driven at a low speed while maintaining the half-clutch state, the driver operates the clutch / pedal stroke shallowly (to make it smaller) and brake pressure Even after passing the release point, the clutch operation is continued without releasing the foot from the clutch pedal. The present invention pays attention to such driving habits, and after the stroke of the clutch pedal reaches the release point of the brake pressure, the clutch pedal is not released once, and then the half clutch operation is continued. When the brake pedal is operated, the brake pedal stroke is operated again to the brake pressure holding start point, and even if the brake pedal is depressed, holding of the brake pressure is started after the holding start point is detected. The greatest feature is that a delay time (t) is provided.
[0012]
That is, the present invention holds and releases the brake pressure of the brake cylinder provided in the brake pressure generating means (15, 16, 17) associated with the brake pedal and the passage for supplying the brake pressure to the brake cylinder. A solenoid valve (9), and a control circuit (10) for supplying a control current to the solenoid valve (9) by using outputs of the vehicle speed sensor (1), the clutch stroke sensor (2), and the gear switch (5) as inputs. And the control circuit (10) brakes in a state where the clutch pedal is stepped on with a stroke larger than a brake pressure holding start point when the brake pedal (11) is stepped on and the vehicle is stopped.・ When the driving operation is performed to release the pedal, the means for holding the brake pressure and the transmission start position with the brake pressure held In hill-start assist and means for releasing the brake pressure is held by the said means the stroke of the clutch pedal is not larger than the release point of the brake pressure is in,
[0013]
After the control circuit (10) performs the operation of holding and releasing the brake pressure, the clutch pedal is stepped over the holding start point again without returning the clutch pedal stroke to zero once. When the brake pedal is depressed, a delay time (t) is provided from when the stroke of the clutch pedal reaches the holding start point until the brake pressure is held.
[0014]
The numbers in the above parentheses are reference numerals for the drawings of an embodiment apparatus to be described later. This is provided to facilitate understanding of the configuration of the invention, and is not intended to limit the configuration of the invention to the embodiments.
[0015]
By adopting such a configuration, the holding start point and the release point are set to substantially equal points of the clutch / pedal stroke, and it is not necessary to provide the offset described above. After starting the vehicle, a slow speed driving operation such as entering a garage or changing the stop position can be performed in a half-clutch state. Since the offset is eliminated, the range in which the driver can change the release point of the brake pressure is increased.
[0016]
The clutch pedal stroke is zero when the state where the clutch pedal is released is detected, but as a practical structure, the clutch pedal stroke is set near zero. It can be the case where the detection point is reached.
[0017]
The delay time (t) is a time for executing one slow speed running, and is suitably several seconds to several tens of seconds. More specifically, it is appropriate to select and set the delay time (t) between 5 seconds and 30 seconds. Before this delay time (t) elapses, when the stroke of the clutch / pedal is operated in the direction in which the stroke becomes smaller again and passes the holding start point again, the delay time is reached when the holding start point is passed again. It is desirable that the time measurement in (t) is reset and the time measurement is started again from time zero.
[0018]
The control circuit of the present invention is preferably configured so that when the release point of the brake pressure is changed by operation, the brake pressure holding start point is automatically changed in conjunction with the release point. . With this arrangement, the offset described above is always maintained at zero or a very small value.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. This device includes a vehicle speed sensor 1, a clutch stroke sensor 2, a service brake switch 3 for detecting an operating state of a service brake, a parking brake switch 4 for detecting an operating state of a parking brake, and a gear for detecting a state of a transmission. A control circuit 10 having each output electric signal of the switch 5 as input information is provided. The control circuit 10 is a program control circuit. The calculation control output of the control circuit 10 is supplied to the electromagnetic valve 9 that drives the brake valve 12 and the alarm device 14.
[0020]
Explaining the brake system, the air pressure is supplied from the air pressure tank 15 to the brake valve 12 via the rear brake valve 16 and the front brake valve 17 which are opened and closed according to the operation of the brake pedal 11. The air pressure controlled by the brake valve 12 is supplied to the rear brake booster 18 and the front brake booster 19. When a control signal is sent to the solenoid valve 9 while air pressure is being sent to the rear brake booster 18 and the front brake booster 19, the brake pressure is maintained even when the brake pedal 11 is released. When the control signal 9 is lost, the brake pressure is released. The operation unit 13 is provided in the driver's seat, and when the operation switch 13a is operated in the ON state, the slope start assist device is in an effective state. When the slope start assist device is not required, the operation switch 13a is turned off. The operation unit 13 is provided with a release point position adjusting end 13b. By operating the adjustment end 13b, the brake pressure release point can be set in a direction in which the clutch pedal stroke is deep or shallow. Operation settings can be made. Further, when the driving operation or the operation of the apparatus is inappropriate and the apparatus cannot follow the operation or when the apparatus has a failure, an alarm is sent out by the alarm buzzer 14a or the alarm lamp 14b.
[0021]
Here, the feature of the present invention is the operation of the control circuit 10. FIG. 2 is a main part flowchart showing the operation of the apparatus control circuit according to the embodiment of the present invention. The clutch pedal when the vehicle speed is zero, the parking brake is released, the transmission is engaged in the starting gear (forward or reverse), and the service brake brake pedal is depressed. Is operated in the direction in which the stroke increases, and the control circuit 10 sends a control signal to the electromagnetic valve 9 when the release point is exceeded. As a result, the electromagnetic valve 9 maintains the brake pressure of the brake / cylinder, and the brake pressure is maintained even when the driver releases the foot from the brake pedal 11.
[0022]
At this time, the apparatus according to the present invention identifies whether there is a history (history) in which the stroke of the clutch pedal is returned to the set stroke zero after the previous release of the brake pressure. When there is a progress of returning, the operation for holding the brake pressure is executed by controlling the electromagnetic valve 9 as described above, but when there is no progress of returning, counting of the delay time (t) is started. During this time, the brake pressure holding operation is suspended, and if this time has elapsed after the set delay time (t), if the vehicle speed is zero, the parking flake is released, and the brake pedal is depressed by gear-in, the brake The operation for maintaining the pressure is executed. The brake pressure releasing operation is the same as that of the conventional device.
[0023]
By performing such control, it is possible to run the vehicle at a low speed while continuing the half-clutch operation after starting using the slope start assist device. This is often the case on busy roads. In addition, when changing the vehicle's stop position or putting in the garage, the clutch / pedal is adjusted to the half-clutch state without releasing the clutch / pedal even after starting the vehicle, and the vehicle moves forward or backward at a slow speed I do. At this time, even if the clutch pedal reaches the brake pressure holding start point again, the clutch pedal has not been returned to zero stroke, so the delay time is started, but the brake pressure holding state is immediately entered. Don't be.
[0024]
As described above, the delay time (t) is suitably set between several seconds and several tens of seconds. However, in this embodiment, the delay time (t) is set to 10 seconds as an example. Therefore, even if the brake pedal is depressed for 10 seconds, the brake pressure is not maintained. If the clutch / pedal stroke is manipulated finely during this slow speed and the brake pressure holding start point may be passed again, the time measurement of the delay time (t) is reset here, and the time measurement is started again. The If the delay time (t) elapses with the clutch pedal stroke increasing past the brake pressure holding start point, then the vehicle speed is zero, the parking brake is released, and the brake pedal is depressed with the gear in The brake pressure is automatically maintained.
[0025]
FIG. 3 is a diagram for explaining a brake pressure holding start point and a release point with respect to the clutch pedal stroke. If the clutch pedal stroke (St) is taken on the horizontal axis and the clutch hydraulic pressure is taken on the vertical axis, the clutch pedal will be stepped in deeply from the released state. It becomes a locus like a curve shown. With the configuration of the present invention, as shown in FIG. 3A, the holding start point and the release point can be set equal to the clutch pedal stroke. FIG. 3B shows a case where an offset is provided between the brake pressure holding start point and the release point (conventional device). If this offset section is made large to some extent, it becomes possible to operate at a slow speed using the half-clutch state in this offset section, but even if the brake pressure release point is changed by operation, the clutch -The degree of freedom to change to the side where the pedal stroke increases will be limited.
[0026]
In addition, when it is necessary to travel at a low speed when the vehicle is at a loading / unloading place or a parking lot, the operation switch 13a of the operation unit provided in the driver's seat is operated to operate a slope start assist device. By stopping the operation of the vehicle and starting the vehicle, the brake pressure is never held at an unintended timing with the half-clutch operation. When the engine key switch is turned off and the engine is stopped, the power supplied to the slope start assist device is cut off. Even when the engine key switch is turned on again, the slope starting assistance device is configured to stop its function until the operation unit 13 is operated. Therefore, even when the vehicle is driven at a low speed immediately after the engine is started by the engine key switch, the function of the present invention does not operate and the brake pressure is not held at an unintended timing.
[0027]
【The invention's effect】
According to the present invention, it is possible to assist the start of a hill where the vehicle can run at a low speed in a half-clutch state without providing an offset with respect to the stroke of the clutch pedal between the brake pressure holding start point and the brake pressure release point. An apparatus can be provided. In the apparatus of the present invention, the half-clutch operation can be performed in a wider range than when the offset described above is set. Further, according to the present invention, the release point of the brake pressure can be changed in a wide range according to the driver's operation.
[Brief description of the drawings]
FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart for explaining the operation of the main part of the control circuit of the embodiment device of the present invention;
FIG. 3 is a diagram illustrating a stroke of a clutch pedal.
(A) In the case of the embodiment device of the present invention (b) In the case of providing an offset (comparative example)
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vehicle speed sensor 2 Clutch stroke sensor 3 Service brake switch 4 Parking brake switch 5 Gear switch 9 Solenoid valve 10 Control circuit 11 Brake pedal 12 Brake valve 13 Operation unit 13a Operation switch 13b Adjustment end of brake pressure release point 14 Alarm device 14a Alarm buzzer 14b Alarm lamp 15 Pneumatic tank 16 Rear brake valve 17 Front brake valve 18 Rear brake booster 19 Front brake booster

Claims (1)

Brake pressure generating means linked to the brake pedal, a solenoid valve provided in a passage for supplying the brake pressure to the brake cylinder and holding and releasing the brake pressure of the brake cylinder, a vehicle speed sensor, a clutch stroke sensor, A control circuit for supplying a control current to the solenoid valve with the output of the gear switch as an input;
The control circuit performs an operation of releasing the brake pedal when the brake pedal is depressed and the vehicle is stopped and the clutch pedal is depressed with a stroke larger than the brake pressure holding start point. The brake pressure is maintained when the transmission is in the starting position and the clutch pedal stroke is reduced beyond the brake pressure release point. A slope start assist device including means for releasing the brake pressure
The control circuit performs the operation of holding and releasing the brake pressure, and then once the clutch pedal is stepped over the holding start point again without the clutch pedal stroke becoming zero. When the vehicle is stepped on, the slope start assist device is provided with a delay time from when the clutch pedal stroke reaches the holding start point to when the brake pressure is held.

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