JPH0891184A - Up-slope start assisting device - Google Patents

Abstract

PURPOSE: To automatically release the temporarily held braking pressure in a preset value when a clutch is pulled out by setting release point in a stroke value by adding a specific length to a stroke value passing through a specific oil pressure value in a process where oil pressure is raised. CONSTITUTION: In a program control circuit 10, braking pressure is held by a solenoid valve 1 when car speed becomes zero under braking pressure not less than a prescribed value and a stroke of a clutch pedal 12 is larger than a prescribed value, and a braking pressure holding condition of the solenoid valve 1 is released when a stroke of the clutch pedal 12 becomes smaller than a preset release point. Information on oil pressure generated by the clutch pedal 12 is taken in from an oil pressure sensor 5, and a release point is set in a stroke value (Lo +LK) by adding a specific length LK to a stroke value Lo passing through a specific oil pressure value Po in a process where the oil pressure is raised.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used as a vehicle driving assistance device. The present invention temporarily holds the braking pressure even when the brake pedal is released when the vehicle speed reaches zero due to the application of a braking pressure above a predetermined level, and the clutch is disengaged. And a slope start assist device that automatically releases the temporarily held braking pressure at a set value. INDUSTRIAL APPLICABILITY The present invention is applied to an automobile equipped with a clutch and a manual shift transmission, and is not applied to an automatic vehicle having no clutch pedal.

[0002]

2. Description of the Related Art A driving operation for starting a slope on a vehicle that is stopped in the middle of a slope in an uphill direction is performed by depressing a clutch pedal with the brake pedal depressed to shift the transmission to a start gear (or a reverse gear). When the clutch is in the half-clutch state, the brake pedal is released and the accelerator pedal is depressed, while the clutch pedal is set and the clutch pedal is gently pulled in the shallower step.
The slope start assist device is a driving assist device that automatically executes this. In other words, the slope start assist device depresses the brake pedal to decelerate the vehicle and the vehicle speed becomes zero (or almost zero).
If the clutch pedal exceeds the predetermined value and the brake pedal is released, the braking pressure is automatically maintained even if the brake pedal is released. Further, when the clutch pedal, on which the transmission has been set and depressed, is released to the set release point, the holding state of the braking pressure is automatically released.

This device takes in a solenoid valve connected so as to maintain braking pressure according to control even when the brake pedal is released, and vehicle speed information, braking pressure information and clutch pedal stroke information. And a program control circuit that electrically controls the solenoid valve. In a vehicle equipped with this device, even if the driver releases the brake pedal while the side brake is not applied, the vehicle is held in a stopped state, so that the driving operation for starting a slope as described above can be performed smoothly. It can be carried out. Further, when driving on a road in a congested state, it is not necessary to continue to press the brake pedal for a long time or repeatedly operate the side brake, so that the driver's fatigue can be reduced.

Such a slope starting assist device is disclosed in Japanese Patent Laid-Open No.
No. 4-60456, JP-A-64-60457, and others. This device has come into widespread use in freight vehicles whose operating conditions change depending on the weight of the vehicle.

As described above, in the above-described hill-start assisting device, when a vehicle stopped on a hill is started,
When the clutch pedal is slowly released, and the stroke of the clutch pedal reaches a preset release point, the braking pressure held is automatically released. Since the proper position of this release point changes depending on the wear state of the clutch, the setting of the release point must also be changed in accordance with the wear state of the clutch. A device that can automatically follow this according to the wear of the clutch is disclosed in Japanese Patent Laid-Open No. 4-2.
It was disclosed in Japanese Patent No. 44462.

This conventional device detects a clutch stroke where the clutch hydraulic pressure generated by the clutch pedal reaches a specific hydraulic pressure P ₀ when the clutch pedal is gently released from the depressed state, and is fixed at this clutch stroke. The stroke obtained by adding the length Lq is used as the set release point. By doing this,
Even if the clutch is worn, the set release point is automatically set to follow.

[0007]

The inventor of the present application repeatedly tested the above-described conventional hill-start assisting device. This conventional device is an excellent device in which the release point set according to the wear of the clutch is changed to follow, but the release point for releasing the braking pressure is at a relatively deep position of the clutch stroke, and the clutch hydraulic pressure is Since the point at which the hydraulic pressure becomes a specific hydraulic pressure P ₀ is detected in the state where the clutch stroke is gently disengaged, the release point is set according to the old history of the clutch being stepped on.

The present invention has been made against such a background, and when the appropriate value of the set release point of the braking pressure with respect to the clutch stroke changes due to wear of the clutch, the release is followed and released. It is an object of the present invention to provide a slope start assist device in which points are automatically changed and set, and release points set according to the latest history are always changed.

[0009]

SUMMARY OF THE INVENTION According to the present invention, when a braking pressure of a predetermined level or more is applied and the vehicle speed reaches zero, if the clutch is depressed, the braking pressure is temporarily released even if the brake pedal is released. It is related to a device that automatically releases the temporarily held braking pressure according to the set value when the clutch is disengaged and is connected so as to maintain the braking pressure according to the control even when the brake pedal is released. And a control circuit for controlling the solenoid valve by taking in vehicle speed information, braking pressure information and clutch pedal stroke information, and the control circuit controls the electromagnetic valve so that the vehicle speed is zero at a braking pressure equal to or higher than a predetermined value. And when the stroke of the clutch pedal is larger than a predetermined value, the solenoid valve holds the braking pressure, and the stroke of the clutch pedal becomes smaller than the set release point. In hill-start assist provided with a control means for releasing the brake pressure holding state of the solenoid valve,
The control circuit takes in information on the hydraulic pressure generated by the clutch pedal, and the release point has a stroke value (L ₀ ) that passes a specific hydraulic pressure value (P ₀ ) in the process of increasing the hydraulic pressure.
₀ ) plus a certain length (Lk) stroke value (L ₀
+ Lk) is set.

[0010] The control circuit, the hydraulic pressure is recorded the oil pressure value that oil pressure value for each reach (P ₀₎ corresponding stroke value _{(P 0) (L 0)} , to the stroke value (L ₀₎ It is preferable that the hydraulic pressure information includes means for calculating a stroke value (L ₀ + Lk) obtained by adding a fixed length (Lk), and the hydraulic pressure information is obtained from a hydraulic pressure sensor provided in a hydraulic circuit of the clutch.

[0011]

The vehicle speed information, the braking pressure information, and the clutch pedal stroke information are fetched, and the solenoid valve is braked when the braking pressure exceeds a predetermined value, the vehicle speed becomes zero, and the clutch pedal stroke is greater than the predetermined value. The pressure is held, and the braking pressure holding state of the solenoid valve is released when the stroke of the clutch pedal becomes smaller than the set release point.

The set release point changes due to wear of the clutch. Therefore, as an initial value, when the clutch is new, information on the hydraulic pressure generated when the clutch pedal is depressed is fetched, and as shown in FIG. 4, a specific hydraulic pressure value (P ₀ ) is generated in the process of the hydraulic pressure rising. The stroke value (L ₀ ) of the point (A ₀ ) passing through
Is set to the stroke value (L ₀ + Lk).

[0013] This oil pressure for each reaches the oil pressure value (P _0), and recording the pressure values corresponding stroke value (P ₀₎ and (L _0), a predetermined length to the stroke value (L ₀₎ It is performed by calculating a stroke value (L ₀ + Lk) obtained by adding (Lk). The information on the oil pressure is taken in from an oil pressure sensor provided in the oil pressure circuit of the clutch.

Next, when the clutch wears, the point where the hydraulic pressure reaches the specific value P ₀ moves from A ₀ to A ₁ . The stroke corresponding to this point A ₁ is L ₁ , and a stroke L ₁ + Lk obtained by adding a fixed length Lk to this stroke L _1.
The point C'corresponding to is set as a new appropriate release point.

Accordingly, when the appropriate value of the release point of the braking pressure set in the clutch stroke changes due to the wear of the clutch, the release point can be automatically changed and set in accordance with the change. It is possible to always change the release point set according to the latest history.

[0016]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the main part of the embodiment of the present invention.

In the embodiment of the present invention, the solenoid valve 1 connected so as to maintain the braking pressure according to the control even when the brake pedal 11 is released, the vehicle speed sensor 2 for detecting the vehicle speed, and the braking pressure are detected. A stop lamp switch 3, a clutch stroke sensor 4 that detects the stroke of the clutch pedal 12, a hydraulic sensor 5 that detects the hydraulic pressure value of the hydraulic circuit of the clutch, a gradient sensor 6 that detects the gradient of the vehicle, and a vehicle speed lever. The neutral switch 7 indicating that the position is in neutral, the vehicle speed sensor 2, the stop lamp switch 3, the clutch stroke sensor 4, the hydraulic pressure sensor 5, the gradient sensor 6 and the neutral switch.
A program control circuit 10 for controlling the solenoid valve 1 by taking the output from the switch 7, and the program control circuit 10
And an alarm device 22 for issuing an alarm when the output of the gradient sensor 6 exceeds a predetermined value while the brake pressure is being held, and when a failure occurs. Is provided. The alarm device 22 is provided with an alarm buzzer 23 that sounds an alarm and an alarm lamp 24 that lights up to generate an alarm.

Further, the program control circuit 10 controls the solenoid valve 1 when the vehicle speed becomes zero when the braking pressure exceeds a predetermined value and the stroke of the clutch pedal 12 is larger than the predetermined value.
When the stroke of the clutch pedal 12 becomes smaller than the set release point, the solenoid valve 1
The control means for releasing the holding state of the braking pressure is provided, and as a feature of the present invention, information on the hydraulic pressure generated by the clutch pedal 12 is fetched from the hydraulic pressure sensor 5, and the release point is set to a specific hydraulic pressure in the process of increasing the hydraulic pressure. means for setting a value (P ₀₎ stroke value passing through (L ₀₎ to the stroke value obtained by adding a predetermined length _{(Lk) (L 0 + Lk} ), each hydraulic pressure reaches the oil pressure value (P ₀₎ The hydraulic pressure value (P ₀ )
And means for recording a stroke value (L ₀ ) corresponding to, and calculating a stroke value (L ₀ + Lk) obtained by adding a constant length (Lk) to this stroke value (L ₀ ).

Next, the operation of the embodiment of the present invention thus constructed will be described.

First, a description will be given of the hill start assisting operation performed during normal traveling. FIG. 2 is a flow chart showing the flow of the brake holding operation in the embodiment of the present invention, and FIG. 3 is a flow chart showing the flow of the brake release operation in the embodiment of the present invention.

The brake holding operation by the program control circuit 10 is as shown in FIG.
Takes in the output from the stop lamp switch 3 and determines whether or not the brake pedal is depressed. If the brake pedal is not depressed, it means that the vehicle is not stopped due to braking, so the sending of the control signal to the solenoid valve 1 is prohibited and the assisting operation for starting the slope is stopped. When the brake pedal is depressed, the output from the vehicle speed sensor 2 is fetched to determine whether the vehicle speed is zero. If the vehicle speed is not zero, the vehicle is running, so the sending of the control signal to the solenoid valve 1 is prohibited and the auxiliary operation for starting the slope is stopped.

When the vehicle speed is zero, the output from the gradient sensor 6 is fetched and it is determined whether or not the current output of the gradient sensor 6 exceeds the set predetermined value S. When the output of the gradient sensor 6 exceeds the predetermined value S, it is determined that the vehicle is moving, and the sending of the control signal to the solenoid valve 1 is prohibited and the auxiliary operation is stopped. If it does not exceed the predetermined value S, it is determined that the vehicle is stopped, and it is determined whether or not the clutch stroke exceeds the predetermined value. If it exceeds the predetermined value, a control signal is sent to the solenoid valve 1, The solenoid valve 1 is driven to operate the brake valve 13 to execute a slope start assisting operation. If it does not exceed the predetermined value, the control signal transmission to the solenoid valve 1 is prohibited and the execution of the auxiliary operation is stopped.

Next, the brake release operation performed during normal traveling will be described with reference to FIG.

When the vehicle is in a brake holding state on a slope, the clutch stroke sensor 4 and the neutral
The output from the switch 7 is taken in and it is determined whether or not the clutch pedal 12 is depressed and the gear is set to the forward drive position (low or second) or the reverse position.

When the clutch pedal 12 is depressed and the gear is set to the starting state, it is judged from the output of the clutch stroke sensor 4 whether or not the stroke is equal to or less than a predetermined stroke. When the stroke is equal to or less than the predetermined stroke, it is assumed that the vehicle is started, and the sending of the control signal to the solenoid valve 1 is prohibited and the brake is released. If the gear is not set to the start state or the depression amount of the clutch pedal 12 is equal to or more than the predetermined stroke,
The control signal is continuously sent to the solenoid valve 1 to maintain the brake holding state.

The brake release position (stepping stroke value of the clutch pedal 12) can be set arbitrarily by adapting to the driver's preference and changes due to wear of the clutch by an operation input from the operation panel 21. The value of the set stroke of the clutch pedal 12 is held until it is reset. If the depression stroke of the clutch pedal exceeds the set reference value, the starting assist operation is continued.

As described above, the setting and changing of the releasing point for releasing the braking pressure in the hill start assisting operation are performed by the operation input from the input unit 21, but the present invention automatically sets and changes the releasing point. It was made possible. Here, the automatic setting and changing operation of the release point for releasing the braking pressure, which is a feature of the present invention, will be described. FIG. 4 is an operation explanatory view (clutch hydraulic pressure hysteresis) for explaining the setting and changing operation of the release point for releasing the braking pressure in the embodiment of the present invention, and FIG. 5 is the setting of the release point for releasing the braking pressure in the embodiment of the present invention. 7 is a flowchart showing a flow of control operation for change and change.

First, the hysteresis of the clutch hydraulic pressure will be described with reference to FIG. Here, the stroke of the clutch pedal 12 (unit: cm) is plotted on the horizontal axis, and the control oil pressure of the clutch (unit: kg / cm ² ) generated by the operation of the clutch pedal 12 is plotted on the vertical axis. It shows the hysteresis of the generated hydraulic pressure with respect to the stroke.

The solid line shows the hysteresis when the clutch is not worn yet, and the broken line shows the hysteresis when the clutch is worn. That is, the clutch pedal 1
When stepping on 2, hydraulic pressure hardly changes with asobi at first. The clutch hydraulic pressure changes significantly when the pedal is further depressed beyond the range of play, and the clutch hydraulic pressure is saturated when the pedal is further depressed. From that state, when you reverse the clutch pedal,
Instead of following the same curve as the previous curve, the hydraulic pressure suddenly drops in a stepwise manner, the hydraulic pressure gradually changes from that value, and when the clutch pedal is further withdrawn, the hydraulic pressure changes suddenly. After going through the territory, it enters the range of Asobi.

On this hysteresis curve, the release point of the proper braking pressure in the half-clutch state is C in the figure.
The point is to pull out the clutch (meet the clutch)
It is advisable to set it in a region where the hydraulic pressure gradually decreases when operating in the direction. This hysteresis curve changes like the curve indicated by the broken line in the figure when the clutch wears. Then, the proper release point C changes to the point C '.

The above-mentioned conventional apparatus follows this as follows. That is, after passing the point C, the clutch hydraulic pressure is measured by the hydraulic pressure sensor to recognize the point B ₀ when the hydraulic pressure reaches the specific value P ₀ . Then, point C is obtained by adding a fixed length Lq to this point B ₀ .

[0032] In the present invention, when Yuku depressing the clutch, i.e., in the process of hydraulic pressure increases, recognizes the points A ₀ to the hydraulic pressure becomes a specific value P _0, constant stroke L ₀ of the clutch pedal at this time A stroke having a value obtained by adding the length Lk is set as a point C.

When the clutch is worn and has a hysteresis as shown by a broken line, the point where the hydraulic pressure becomes the specific value P ₀ is from A ₀ to A
Move to ₁ . The stroke corresponding to the point A ₁ is L ₁ , and the point C ′ corresponding to the stroke L ₁ + Lk obtained by adding the constant length Lk to this stroke L ₁ is a new proper release point.

That is, in the conventional apparatus, since the B ₀ point is recognized after the C point in the course of a series of clutch operations, the C point is changed based on the B ₀ point recorded by the previous clutch operation. On the other hand, in the present invention, point A ₀ is a point recognized before point C, so point C is calculated based on point A ₀ recorded by the current clutch operation.

Next, the control operation for setting and changing the release point will be described with reference to FIG.

The program control circuit 10 confirms whether or not the stroke of the clutch pedal 12 is displaced. This takes in a specific value P ₀ of the clutch oil pressure from the oil pressure sensor 5, and the clutch pedal 12 corresponding to the specific value P _0.
This is done by recognizing the stroke Li. Then, a calculation for adding a fixed length Lk to the stroke Li corresponding to the recognized specific value P ₀ is performed to rewrite the set value of the release point, and the stroke of the clutch pedal 12 is set to the set value L 0.
Check if i + Lk is exceeded.

When the stroke exceeds the set value Li + Lk, the clutch pedal is released and the stroke is set to the set value Li.
It is detected whether or not the pressure has returned to + Lk, and when it returns, the control for releasing the braking pressure is executed.

[0038]

As described above, according to the present invention, when the appropriate value of the release point of the braking pressure set in the clutch stroke changes due to wear of the clutch, the release point is automatically tracked according to the change. The release point can be changed and set, and the release point set according to the latest history can always be changed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of an embodiment of the present invention.

FIG. 2 is a flowchart showing a flow of a brake holding operation by a program control circuit in the embodiment of the present invention.

FIG. 3 is a flowchart showing a flow of a brake release operation by the program control circuit in the embodiment of the present invention.

FIG. 4 is an operation explanatory view (clutch hydraulic pressure hysteresis) illustrating an operation of setting and changing a release point for releasing a braking pressure in the embodiment of the present invention.

FIG. 5 is a flowchart showing a flow of control operation for setting and changing a release point for releasing the braking pressure in the embodiment of the present invention.

[Explanation of symbols]

 1 Solenoid Valve 2 Vehicle Speed Sensor 3 Stop Lamp Switch 4 Clutch Stroke Sensor 5 Oil Pressure Sensor 6 Gradient Sensor 7 Neutral Switch 10 Program Control Circuit 11 Brake Pedal 12 Clutch Pedal 13 Brake Valve 21 Operation Panel 22 Alarm Device 23 Alarm Buzzer 24 Alarm lamp

Claims (3)

[Claims] 1. A solenoid valve connected so as to maintain a braking pressure according to control even when the brake pedal is released, and a solenoid valve for taking in vehicle speed information, braking pressure information and clutch pedal stroke information. And a control circuit for controlling the clutch pedal, wherein the control circuit causes the solenoid valve to hold the braking pressure when the vehicle speed becomes zero at a braking pressure equal to or higher than a predetermined value and the stroke of the clutch pedal is larger than the predetermined value. In a slope start assist device including control means for releasing the braking pressure holding state of the solenoid valve when the stroke becomes smaller than the set release point, the control circuit provides information on the hydraulic pressure generated by the clutch pedal. Incorporation, the release point has a constant length (Lk) at a stroke value (L ₀ ) that passes a specific hydraulic pressure value (P ₀ ) in the process of increasing the hydraulic pressure. Is set to a stroke value (L ₀ + Lk) obtained by adding Wherein the control circuit, the hydraulic pressure is the hydraulic pressure value (P ₀₎ that oil pressure value for each reach the corresponding stroke value (P ₀₎ (L ₀₎ is recorded, the stroke value (L ₀ 3. The slope start assist device according to claim 1, wherein a stroke value (L ₀ + Lk) is calculated by adding a constant length (Lk) to the above). 3. The slope start assist device according to claim 2, wherein the hydraulic pressure information is obtained from a hydraulic pressure sensor provided in a hydraulic circuit of the clutch.