JPH0820321A - Slope start assisting device - Google Patents

Abstract

PURPOSE:To improve the safety at the time of a slope start by releasing a service brake on condition that the vehicle speed is practically zero, a parking brake is released, a transmission is set to a start gear, a clutch is temporarily disengaged then engaged beyond the release point. CONSTITUTION:A program control circuit 10 confirms whether a parking switch 4 is set to the off-state or not when the vehicle speed is practically zero based on the output from a vehicle speed sensor 1 and releases a service brake when the parking switch 4 is set to the on-state. When the parking switch 4 is set to the off-state, the program control circuit 10 judges whether a gear-in switch 5 is set to the on-state or not. When the gear-in switch 5 is set to the on-state, the program control circuit 10 judges that a transmission is set to a start gear (including reverse) and receives the detected output from a clutch stroke sensor 2 to judge whether a clutch is temporarily disengaged or not. When the clutch is temporarily disengaged then engaged beyond the release point, a solenoid valve 9 is turned off, and the service brake is released.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is used in automobiles. The present invention relates to an improvement in a device for automatically maintaining a braking state. The present invention, when the vehicle starts from a state where the vehicle is stopped on a slope, the brake is automatically held even if the driver releases the foot from the brake, and when the clutch pedal exceeds the set release point, the automatic The present invention relates to an improvement in a device for releasing a brake.

[0002]

2. Description of the Related Art The above-described hill-start assisting device is a device that has been known for a long time, but various improvements have been made to implement it on a practical vehicle. Among the improvements, what should be noted in connection with the present invention is JP-A-64-604.
This is disclosed in Japanese Patent Publication No. 59. This makes it possible to subtly adjust the release point set on the clutch pedal, designing and manufacturing a practical device that does not reverse the vehicle when starting on a slope and does not put a significant load on the clutch. This is the technology that has contributed to this.

As a matter of course, various improvements have been made in order to provide a practical hill-starting assisting device that can stably operate for a long period of time under severe operating conditions. In particular, safety measures need to be sufficiently improved so as not to cause a serious failure even if the driver makes an erroneous operation. For example, when the parking brake is released and the vehicle is operated to start on a slope, and the brake pressure is temporarily retained even after the brake pedal is released, the driver forgets this and drives the vehicle. It is dangerous to leave the seat, and a practical device needs a device for safely responding to such a situation.

[0004]

The inventor of the present application has found that the technique disclosed in the above-mentioned publication still needs improvement, while performing many tests on the slope starting assist device and making many improvements. . It is one of the conditions to hold the brake pressure temporarily even when the brake pedal is released.
The technique disclosed in the above publication sets that the transmission is not in the neutral position. That is, when the transmission is in the neutral position, it is impossible to execute the start on the slope, so that the neutral switch detects that the transmission is in the neutral position, and the neutral switch is in the ON state. At times, the control logic is such that the operation for releasing the holding of the brake pressure is not performed regardless of other conditions. This control logic is quite correct.

However, in the course of conducting the test, it was found that the actual transmission is not in the neutral position, that is, the gear is not in the engaged state. The widely used neutral switch of the transmission is to detect that the transmission is reliably in the neutral position, and there is a gap between the neutral position and the state where the transmission gear is engaged. is there.

FIG. 3 is a diagram for explaining the angle of the transmission shift shaft. In FIG. 3, the transmission is surely in the neutral position when the transmission shift shaft is in the range of the angle θ ₁ , and the transmission is in the gear closing state when the transmission shift shaft is in the range of the angle θ _2. But this angle θ
There is a condition of an angle Δθ between ₁ and the angle θ ₂ , and when the transmission shift shaft is at this angle Δθ, it is not in the neutral position but not in the position where the gear is surely engaged. There is an indeterminate state.

When the transmission lever is operated while the brake pressure is being held and the transmission shift shaft is in the uncertain state indicated by the angle Δθ, if the clutch pedal is connected after the pedal is released beyond the release point, The control circuit of the hill start assist device determines that the hill start is to be executed, and releases the brake pressure. If the driver thinks that the vehicle will start on a slope when the gear is not fully engaged, and if it is found that the vehicle will not start on a slope when performing a driving operation, the vehicle will not be released until the brake pedal is pressed again. There is a slight backtrack on the slope.

The present invention has been made against such a background, and the transmission surely operates in a starting gear (for example, first speed and second speed).
It is an object of the present invention to provide a device for performing a brake pressure releasing operation for starting a slope only when the gear is engaged in the reverse gear. An object of the present invention is to improve the usability of a slope start assist device. SUMMARY OF THE INVENTION It is an object of the present invention to provide a slope start assist device that can improve the safety of the driver even when the driver performs an uncertain operation. It is an object of the present invention to provide a slope starting assist device that operates reliably.

[0009]

According to the present invention, in place of the neutral switch for detecting that the transmission is in the neutral position, the transmission is reliably put in the starting gear position or the reverse gear position. Gear in to detect
It is characterized by controlling a slope start assisting operation by using a switch. Here, the gear-in switch does not simply output the signal of the reverse logic of the neutral switch, but also includes the fact that the transmission is not in the neutral position, and furthermore, the transmission is reliably put into the starting gear. , Or a switch for detecting a state in which the gear is set in the start gear or the reverse gear.

That is, the present invention includes a vehicle speed sensor, a clutch stroke sensor, a service brake switch, a parking brake switch, and a gear-in switch for detecting that the transmission is in the starting gear. An electromagnetic valve that holds the service brake in a braking state even when the brake pedal is released, and a control circuit that takes in the outputs of the sensors and switches and controls the electromagnetic valve are provided. Is zero and
It is provided with a control means for releasing the service brake on condition that the parking brake is released, the transmission is in the starting gear, and the clutch is disengaged and then connected beyond the release point. Characterize.

[0011] A gradient sensor is provided, and the control circuit includes means for prohibiting holding the service brake in a braking state when the gradient of the vehicle is equal to or less than a predetermined value.
It is preferable that the control circuit includes means for detecting that the transmission is in the reverse gear, and the control circuit enables the control means even when the transmission is in the reverse gear.

[0012]

The detection output from the vehicle speed sensor indicates substantially zero vehicle speed, and the output from the parking brake switch indicates that the parking brake is released.
When the output from the clutch stroke sensor indicates that the clutch has been disengaged and then engaged beyond the release point, the service brake is released on these conditions.

When the vehicle is equipped with a gradient sensor, it is prohibited to keep the service brake in the braking state when the gradient of the vehicle is below a predetermined value. Further, when the means for detecting that the transmission is in the reverse gear is provided, the control is enabled even if the transmission is in the reverse gear.

This ensures that the transmission has a start gear (1
(3rd speed and 2nd speed) or only when the vehicle is in the reverse gear, the assisting operation for starting a slope can be performed to enhance the safety in starting a slope.

[0015]

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 embodiment of the present invention.

In the embodiment of the present invention, a vehicle speed sensor 1 for detecting a vehicle speed, a clutch stroke sensor 2 for detecting a stroke of a clutch, a service brake switch 3 for detecting a braking state by a service brake, and a braking by a parking brake. Parking brake switch 4 for detecting the state and gear-in switch 5 for detecting that the transmission is in the start gear or the reverse gear
, A gradient sensor 6 for detecting the gradient of the vehicle, a brake
Even if the pedal 11 is released, the solenoid valve 9 that adjusts the brake valve 12 according to the control signal to maintain the service brake in the braking state, and the output of the gradient sensor 6 that exceeds the predetermined value while the brake pressure is maintained An alarm device 14 for issuing an alarm when on a slope and when a failure occurs, and a program control circuit 10 for controlling the solenoid valve 9 by taking in outputs from the respective sensors and switches.
The program control circuit 10 is provided with an input unit 13 for inputting an operation. The alarm device 14 is provided with an alarm buzzer 14a for generating an alarm by sound and an alarm lamp 14b for emitting an alarm by lighting.

The program control circuit 10 includes a vehicle speed sensor 1
The vehicle speed detected by is substantially zero, the parking brake is released, the transmission is in the start gear or reverse gear, and the clutch is disengaged and then connected past the release point. Means for releasing the service brake on the condition that the vehicle brakes are kept below the predetermined value, the means for prohibiting the service brake from being held in the braking state when the vehicle gradient is equal to or less than a predetermined value, and Means for enabling the means for releasing the service brake, and means for issuing an alarm to the alarm device 14 are provided.

The gear-in switch 5 will now be described. As shown in FIG.
Upper cover 1 with neutral switch 15
6 and the transmission shift shaft 17 is turned to the left side in FIG. 3, for example, the neutral switch 15 is moved at the position P ₁ moved by the angle θ _1.
4 is in the OFF state as shown in FIG. 4, but the gear-in switch 5 is still in the OFF state, and when the position of Q _{1 in} FIG. It turns on. transmission·
Similarly, when the shift shaft 17 is turned to the right by an angle θ ₁ , the neutral switch 15 is turned off at the position P _2.
Although it is in the F state, the gear-in switch 5 is in the OFF state, and is in the ON state when it reaches the position of Q _{2 in} FIG. 3 further rotated by the angle Δθ.

This is because the transmission shift shaft 17 is turned to either the left or right, and the neutral
The range of the angle Δθ until the switch 15 is turned off and the gear-in switch 5 is turned on is ON, OF
Since F is ambiguous, the neutral switch is turned on and off and the gear-in switch is turned on and off at an angle Δθ.

A feature of the present invention is that it is detected that the gear is surely put in the starting position or the reverse position,
By this, the brake pressure release control for starting a slope is performed.

Next, the operation of the embodiment of the present invention thus constructed will be described. FIG. 5 is a flow chart showing the flow of operations in the embodiment of the present invention.

The program control circuit 10 takes in the detection output from the vehicle speed sensor 1, checks if the parking brake switch 4 is in the off state when the vehicle speed is substantially zero, and if it is in the on state, the parking brake switch 4 is in the off state. Unconditionally release the service brake as the brake is in use.
If it is in the off state, it is determined that the parking brake is released and whether or not there is a malfunction in the device is confirmed. If there is a failure condition, an alarm signal is sent to the alarm device 14, an alarm sound is generated from the alarm buzzer 14a, and the alarm lamp 14b is turned on to notify that there is a failure condition.

If there is no abnormality, it is confirmed whether or not the gear-in switch 5 is in the on state, and if it is in the on state, it is determined that the transmission is in the state of being put in the starting gear (including the reverse gear). Take the detection output from 2 and check whether the clutch has been disengaged. If the clutch is in the disengaged state, check whether it is connected after the disengagement point after disengagement, and if it is connected after the disengagement point after disengagement,
The solenoid valve 9 is turned off to release the service brake.
After the disconnection, if the connection is not established beyond the release point, the braking state by the service brake is continuously maintained.

The present invention replaces the neutral switch 15 which detects when the transmission is in the neutral position,
The gear-in switch 5 is used. Thus, as shown in FIG. 3, the transmission is in the neutral position when the transmission shift shaft 17 is in the range of the angle θ ₁ , and the transmission is in the range of the angle θ ₂ when the transmission shift shaft 17 is in the range of the angle θ _2. It is in the gear-in state, but when it is in the range of Δθ between the angle θ ₁ and the angle θ ₂ , it is neither in the neutral position nor in the position where the gear is surely engaged. It can be avoided. That is, it is possible to reliably detect the state in which the transmission is in the start gear or the reverse gear, including the fact that the transmission is not in the neutral position, and control the slope start assist operation.

The program control circuit 10 also takes in the detection output from the gradient sensor 6 and keeps the service brake in a braking state when the vehicle is on a slope and reaches the release point unless the vehicle is on a steep grade, which is dangerous. Sometimes the holding state is released to improve driving operability.

[0026]

As described above, according to the present invention, the brake pressure releasing operation for starting a slope is performed only when the transmission is surely engaged in the starting gear (first gear and second gear) or the reverse gear. When the vehicle is in an uncertain state where the gears are not securely engaged, the brake pressure release operation for starting the slope is surely prohibited, so even if the driver makes an uncertain operation, the start on the slope is guaranteed. Can be

[Brief description of drawings]

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

FIG. 2 is a view showing a mounting state of the gear-in switch according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating a neutral position and a gear-in position due to rotation of a transmission shift shaft.

FIG. 4 is a diagram illustrating a neutral region and a gear-in region in the embodiment of the present invention.

FIG. 5 is a flowchart showing a flow of operations in the embodiment of the present invention.

[Explanation of symbols]

 1 vehicle speed sensor 2 clutch stroke sensor 3 service brake switch 4 parking brake switch 5 gear-in switch 6 gradient sensor 9 solenoid valve 10 program control circuit 11 brake pedal 12 brake valve 13 input unit 14 alarm device 14a alarm buzzer 14b Warning lamp 15 Neutral switch 16 Upper cover 17 Transmission shift shaft

Claims (3)

[Claims] 1. A vehicle speed sensor, a clutch stroke sensor, a service brake switch, a parking brake switch, a gear-in switch for detecting that the transmission is in a starting gear, and a brake pedal released. The control circuit includes a solenoid valve that holds the service brake in a braking state even if the vehicle is operated, and a control circuit that takes in the outputs of the sensors and switches and controls the solenoid valve. Provided with a control means for releasing the service brake on condition that the parking brake is released, the transmission is in the start gear, and the clutch is disengaged and then connected beyond the release point. Slope start assist device. 2. The slope starting assist device according to claim 1, further comprising a slope sensor, wherein the control circuit includes means for prohibiting holding the service brake in a braking state when the slope of the vehicle is equal to or less than a predetermined value. 3. The control circuit includes means for detecting when the transmission is in the reverse gear, and the control circuit enables the control means even when the transmission is in the reverse gear. Or the slope start assist device described in 2.