JP2004347079A - Safety device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely prevent unexpected motion of a vehicle provided with an automatic transmission against a will of a driver even if air pressure for operating brake is insufficient. <P>SOLUTION: In the vehicle provided with an automatic transmission for controlling air pressure with a brake pedal to hydraulically operate a wheel brake, a lock mechanism 11 to an operating lever 10 of the automatic transmission operates when a low-pressure switch detects that the air pressure inside an air tank is less than a set value capable of generating sufficient pressure in the wheel brake to constrain the operating lever 10, which is thrown into a parking range, in the parking range. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a safety device for a vehicle or the like equipped with an automatic transmission provided with a so-called air overbrake, which operates a wheel brake by hydraulic pressure obtained by boosting the positive air pressure controlled by a brake pedal.
[0002]
[Prior art]
In a conventional vehicle equipped with an automatic transmission equipped with an air overbrake, the engine is started in a state where the air pressure in the air tank filled from the air compressor has been reduced due to a relatively long stoppage, and If the automatic transmission's operating lever is shifted to the drive range and parked even though the low pressure alarm is normally activated to warn the driver due to a decrease in air pressure, the air pressure The vehicle is mainly stopped by the parking brake because it is difficult to apply the foot brake due to lack of gear.However, when the stall ability of the automatic transmission is relatively large, the driver must drive the parking brake sufficiently to drive the vehicle. It is conceivable that the vehicle starts to move against the will of the person.
[0003]
Note that a parking brake control device described in Patent Literature 1 below is conventionally known.
[0004]
[Patent Document 1]
Japanese Utility Model Registration No. 2593980 [0005]
[Problems to be solved by the invention]
An object of the present invention is to surely prevent a vehicle equipped with an automatic transmission from starting to move against the driver's will even when the air pressure for activating a brake is insufficient.
[0006]
[Means for Solving the Problems]
For this reason, the vehicle safety device according to the present invention is a vehicle that is equipped with an automatic transmission and controls the air pressure with a brake pedal to hydraulically operate the wheel brake. Has a lock mechanism for restraining the operation lever of the parking range.
[0007]
That is, when the air pressure controlled by the brake pedal to hydraulically actuate the wheel brake is less than the set value, the lock mechanism restricts the operation lever of the automatic transmission to the parking range, thereby shifting the operation lever to the drive range or the like. Is suppressed, even if the air pressure in the air tank is less than the set value due to the vehicle being stopped for a relatively long time, etc. It is possible to prevent the vehicle from starting moving against the driver's will.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
In FIG. 1 in which a solid line indicates an air pressure path and a dashed line indicates a hydraulic path, in an air overbrake of a vehicle equipped with an automatic transmission, an air tank 1 is filled with pressurized air from an air compressor 2 and is operated by a driver of the vehicle. The air pressure controlled by the dual brake valve 4 in response to the operation of the brake pedal 3 is transmitted to the brake boosters 5 and 6, and the brake boosters 5 and 6 respectively convert the control air pressure into a brake oil pressure to increase the brake pressure. The front wheel brake 7 is actuated by the brake oil pressure transmitted from 5, and the rear wheel brake 9 is operated by the brake oil pressure transmitted from the brake booster 6 via the load sensing valve 8.
[0009]
As shown in FIG. 2, the lock mechanism 11 for the operation lever 10 of the automatic transmission includes a brake switch 12 for detecting the operation of the brake pedal 3, and the operation lever 10 of the automatic transmission is put into the parking range. And a low-pressure switch 14 that detects that the air pressure in the air tank 1 has not reached a set value sufficient to generate sufficient brake oil pressure by the brake boosters 5 and 6. Each signal is received, and a signal from the low pressure switch 14 is sent to an alarm device 15 such as a lamp or a buzzer in the meter cluster.
[0010]
In the above-described device, when the air pressure of the set value is held in the air tank 1, the low-pressure switch 14 and the alarm device 15 are inactive, and like the conventional device,
(1) When the brake switch 12 detects the operation of the brake pedal 3 and the parking switch 13 detects that the operation lever 10 of the automatic transmission has been put into the parking range, the lock mechanism 11 is deactivated. Then, the operation lever 10 is allowed to be put into a range other than the parking range,
(2) When the brake switch 12 does not detect the operation of the brake pedal 3 and the parking switch 13 detects that the operation lever 10 of the automatic transmission has been put into the parking range, the lock mechanism 11 operates. The operating lever 10 is restrained by the parking range,
(3) If the brake switch 12 detects the operation of the brake pedal 3 and the parking switch 13 does not detect that the operation lever 10 of the automatic transmission has been put into the parking range, the lock mechanism 11 does not operate. Actuation, the operating lever 10 is allowed to enter a range other than the parking range,
(4) If the brake switch 12 does not detect the operation of the brake pedal 3 and the parking switch 13 does not detect that the operation lever 10 of the automatic transmission has been put into the parking range, the lock mechanism 11 As a result, the operation lever 10 is allowed to enter a range other than the parking range.
[0011]
However, when the low pressure switch 14 detects that the air pressure in the air tank 1 is lower than the set value, the low pressure switch 14 activates an alarm device 15 to warn a driver of the vehicle or the like of a decrease in the air pressure in the tank 1. On the other hand, regardless of the operation or non-operation of the brake switch 12 and the parking switch 13, the lock mechanism 11 is operated based on the signal from the low pressure switch 14, and the operation lever 10 that has been put into the parking range is moved to the parking range. As a result, the operation lever 10 cannot be put into a range other than the parking range.
[0012]
Therefore, since the vehicle has been stopped for a relatively long period of time and the air pressure in the air tank 1 filled from the air compressor 2 gradually decreases and becomes less than the set value, the brake boosters 5 and 6 provide sufficient braking. When the driver starts the engine in a state where it is difficult to generate the oil pressure, the operation of the lock mechanism 11 is performed until the air pressure in the air tank 1 reaches the above-described set value by the operation of the air compressor 2. As a result, the operation lever 10 is restrained by the parking range and is prevented from being put into the drive range or the like. Therefore, even if the effect of the parking brake itself is not sufficient, the driver's stall ability of the automatic transmission causes the driver's stall ability. It is possible to prevent the vehicle from starting to move unexpectedly, and therefore it is possible to easily increase the safety of the vehicle
[0013]
In addition, the above-described device can be simply configured by only partially adding the control circuit from the existing low-voltage switch 14 to the existing lock mechanism 11, and does not involve extra cost increase. It has a great practical advantage that can be easily applied to conventional devices.
[0014]
The above embodiment is directed to a vehicle provided with an air overbrake. However, a brake that is boosted and controlled by a brake pedal to control the air negative pressure obtained from a negative pressure source such as an engine intake negative pressure. When a vehicle equipped with an automatic transmission equipped with a so-called vacuum booster brake that activates the wheel brake by hydraulic pressure and the air negative pressure in the vacuum tank is less than the set value that can generate sufficient brake hydraulic pressure Even if the operation lever of the automatic transmission is restricted to the parking range by the lock mechanism, the same operation and effect as those of the above-described embodiment can be obtained.
[0015]
【The invention's effect】
In the vehicle safety device according to the present invention, when the air pressure controlled by the brake pedal to hydraulically operate the wheel brake is less than a set value, the lock mechanism reliably suppresses the shift of the operation lever to the drive range or the like. Even if the air pressure in the air tank is less than the set value, it is possible to suppress inappropriate shift changes of the operation lever and prevent the vehicle from starting against the driver's will, It is possible to easily increase the safety of the vehicle.
[Brief description of the drawings]
FIG. 1 is a schematic system diagram in an embodiment of the present invention.
FIG. 2 is a block configuration diagram of a main part in the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Air tank 2 Air compressor 3 Brake pedal 4 Dual brake valve 5, 6 Brake booster 7 Front wheel brake 9 Rear wheel brake 10 Operating lever 11 Lock mechanism 12 Brake switch 13 Parking switch 14 Low pressure switch 15 Alarm device

Claims (3)

A vehicle in which an automatic transmission is equipped and a wheel brake is hydraulically operated by controlling air pressure by a brake pedal and having a lock mechanism for restricting an operation lever of the automatic transmission to a parking range when the air pressure is less than a set value. Vehicle safety devices. The vehicle safety device according to claim 1, wherein the air pressure is a positive pressure obtained by an air compressor. The vehicle safety device according to claim 1, wherein the air pressure is a negative pressure obtained from a negative pressure source.

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