JPH0422743B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake lock device for a vehicle, and more particularly to a brake lock device for a vehicle in which the foot brake is automatically electromagnetically locked when the vehicle is stopped.

A brake lock device that electromagnetically locks the foot brake of a vehicle under predetermined conditions is well known, and an object of the present invention is to provide a device that facilitates braking operations on slopes or when waiting at traffic lights, and that is suitable for use by persons with physical disabilities. I can do it.

In this type of brake lock device, the locking action is such that the braking state is kept locked by an electromagnetic solenoid under a predetermined condition, such as when the foot brake is applied and the vehicle speed drops below a predetermined value. When the vehicle starts from this brake locked state, the brake lock is released by operating the accelerator, and when a main parking braking operation such as a parking brake or a shift operation to the parking position of an automatic transmission vehicle is performed, the brake lock is released. The brake lock is released.

Conventionally, in this type of brake lock device, the vehicle speed, which is the main operating condition, is detected from the rotation of the tires, so when a tire lock phenomenon occurs, the brake lock device detects the vehicle speed, which is the main operating condition, even though the vehicle is actually running. However, there was a problem in that the brake lock was activated due to the determination that the vehicle speed was zero, and the tire lock condition was not resolved. Therefore, conventionally, when such tire lock occurs, a device has been provided that prohibits brake lock by monitoring the deceleration of the vehicle.

However, such tire lock detection means cannot necessarily perform an accurate detection operation, and in conventional devices, brake lock is prohibited in anticipation of safety before tire lock occurs, and as a result, normal brake lock is prohibited when tire lock does not occur. There is a problem in that the brake lock is often prohibited in the detection state, and the advantages of the brake lock cannot be fully utilized.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide an improved vehicle that can quickly cancel the inhibition of brake lock after erroneously detecting or canceling tire lock by an extremely simple operation. The object of the present invention is to provide a brake lock device.

In order to achieve the above object, the present invention includes a brake lock control circuit that outputs a brake lock signal that electromagnetically locks the foot brake of a vehicle under predetermined conditions, and locks the brake and tires when braking the vehicle. A brake locking device for a vehicle that prohibits the brake lock when a brake lock occurs includes a brake operation detection circuit that detects a braking operation by the foot brake and outputs a short-time braking operation signal, and a vehicle speed detection circuit that outputs a delayed vehicle speed signal after a predetermined time delay. a delay output circuit, a comparator that compares the delayed vehicle speed signal with a predetermined low speed reference value, and calculates the output of the comparator and the braking operation signal to cause tire lock to occur when the vehicle speed immediately before the braking operation is below the predetermined value. The present invention is characterized in that it includes an arithmetic circuit that outputs a brake lock trigger signal regardless of the prohibition of brake lock due to the brake lock, and is capable of quickly locking the brake when the tire lock is released.

Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a preferred embodiment of the brake locking device according to the present invention, in which an electromagnetic brake 10 is provided for electromagnetically locking a foot brake pedal (not shown) in its depressed braking state. A brake lock signal is supplied to the electromagnetic brake from a brake lock control circuit 11 under predetermined conditions. The brake lock control circuit 11 includes a holding condition determination circuit 12 and a self-hold circuit 14.
A determination circuit 12 determines a predetermined brake lock condition based on signal input from various sensors installed in the vehicle, and applies a brake lock trigger signal to the self-hold circuit 14 to activate the electromagnetic brake 10. Lock the brakes.

The holding condition determination circuit 12 in this embodiment also has a vehicle tire lock detection function, and when a tire lock occurs, output of a brake lock trigger signal is prohibited to prevent the brake from being locked when the tires are locked. In addition, self-hold circuit 1
A reset signal is supplied to the reset input 4 from an accelerator switch or a parking switch via an OR gate 16, and the brake lock is immediately released depending on whether the vehicle is running or stopped.

A feature of the present invention is that even if brake locking is prohibited due to the tire lock detection described above, the brake lock is promptly performed when tire lock is resolved or tire lock is falsely detected. For this purpose, a circuit is added to detect when the brake is pressed again.

In other words, even if a tire lock occurs, if you press the foot brake again (depress it twice), the tire lock will be resolved and a correct braking condition will be obtained.In such a case, there is no need to prohibit brake lock, and normal It is preferable to make the brake lock work effectively, and similarly, even when a tire lock is erroneously detected, it is preferable to make the brake lock work by pressing the brake again when a vehicle is detected.

As mentioned above, when reapplying the brakes, it is insufficient to simply detect the brake operation electromagnetically. In order to accurately determine these necessary conditions, the present invention detects various conditions described below.

The first condition is to detect that a braking operation has been performed, and for this purpose, a braking operation detection circuit 18 is provided, and the braking operation detection circuit 1 in the embodiment
8 is a foot brake switch 20 and a delay circuit 22
It also includes an inverter 24. The foot brake switch 20 is turned off in the non-braking state, and the output of the delay circuit 22 becomes "H", and the inverter 2
The output of No. 4 is "L". In a braking state where the foot brake is depressed, the switch 20
is turned on, and the output of the delay circuit 22 changes to "L" after a predetermined short period of time, while the inverter 24
The output becomes "H" at the start of braking. Therefore, the brake operation detection circuit 18 can detect a short-time brake operation signal after the brake operation.

The second condition for detecting re-depression in the present invention is to detect the vehicle speed immediately before the braking operation is performed, and for this purpose, a vehicle speed delay output circuit 26 is provided. The vehicle speed delay output circuit 26 includes an FV converter 28 that converts a vehicle speed signal obtained from a reed switch or the like that electrically detects tire rotation into a voltage signal, and a delay circuit 30, and outputs a momentary vehicle speed signal, in this case. The tire rotational speed is delayed by a predetermined time and output as a delayed vehicle speed signal. and,
This delayed vehicle speed signal is compared with a predetermined reference value, in this embodiment, a reference value of 10 km/h, by the comparator 32, and when the delayed vehicle speed is less than this reference value, the comparator 32 outputs an "H" signal. Output.

In the present invention, the output of the comparator 32 and the output of the braking operation detection circuit 18 are calculated by an arithmetic circuit 34, and the arithmetic circuit 34 in the embodiment includes AND gates 36 and 38, The arithmetic circuit 34 determines that the brake operation has been performed and that the vehicle speed immediately before the braking operation is less than or equal to a predetermined value, and the arithmetic circuit 34 outputs a brake lock trigger signal. This brake lock trigger signal is supplied to the OR gate 40 together with the output of the holding condition determination circuit 12 described above, and when a desired condition is satisfied regardless of whether or not the tire lock is prohibited, a trigger signal is applied to the self-hold circuit 14 to lock the brake. Activate.

The embodiment of the present invention has the above configuration, and its operation will be explained below.

The occurrence of tire lock is determined by the holding condition determination circuit 12, and when tire lock occurs,
Even if other holding conditions are met, no brake lock trigger signal is applied to the self-hold circuit 14. As is well known, tire lock occurs when the vehicle speed is above a certain value. Therefore, when such tire lock occurs, even if a braking operation is detected by the braking operation detection circuit 18, the vehicle speed delay output is generated. Since the delayed vehicle speed of the circuit 26 exceeds the predetermined reference value, the comparator 32 outputs an "L" signal, and as a result, the arithmetic circuit 34
The output becomes "L" and the brake lock does not work. If the tire lock condition continues, the vehicle speed signal becomes zero, and the output of the comparator 32 becomes "H".
becomes. However, since the delay time of the delay circuit 22 of the braking operation detection circuit 18 is set to a short time, the output of the delay circuit 22 has already become "L" at this time, and the arithmetic circuit 34 has not output the brake lock trigger signal. There is no output. By setting the delay time of the delay circuit 22 in this way, it is possible to prevent the brakes from being erroneously locked when the tires lock.

That is, since the vehicle speed signal is normally obtained from the tire rotational speed, when a tire lock occurs, a signal indicating the vehicle speed is zero is output, and at this time a braking operation is being performed. Therefore, the holding condition determination circuit 12 works to stop the brake lock by locking the tires, but on the other hand, since zero vehicle speed is detected, if there is no vehicle speed delay output circuit 26, etc., a brake lock trigger signal would be output. It is conceivable that the brakes will be locked. However, in the present invention, the vehicle speed signal is delayed by a predetermined period of time by the vehicle speed delay output circuit 26, thereby preventing output of such an erroneous brake lock trigger signal. For this reason, it is preferable that the delay time of the vehicle speed delay output circuit 26 in the embodiment is set longer than the delay time of the braking operation detection circuit 18, thereby preventing the output of the erroneous brake lock trigger signal. Prevented.

As described above, it is possible to reliably prohibit the brake lock when a tire lock occurs, but even when a tire lock occurs or when a tire lock is falsely detected, it is preferable to activate the brake lock immediately if the vehicle speed decreases. .

However, if only a decrease in vehicle speed is detected, a malfunction will occur due to the apparent zero vehicle speed signal due to tire lock, as described above. Therefore, in the present invention, only the re-depression of the foot brake when the vehicle speed decreases is detected. It is understood that the brake operation detection circuit 18 outputs only short-term pulses so that the brake lock will not be resumed even if the brake is continued to be depressed. .

When a tire lock occurs, the driver normally depresses the foot brake again to take action to eliminate the tire lock. When the tire lock is released by re-depressing the brake, the apparent zero vehicle speed returns to the correct vehicle speed signal again, and the correct braking action is again obtained by re-depressing the brake. As a result of this re-depression of the brake, the braking operation detection circuit 18 again outputs a short braking operation signal, but immediately before this, the tire lock has been released as described above.
The vehicle speed delay output circuit 26 outputs the vehicle speed when the tire lock is released, and if this exceeds a predetermined value, the arithmetic circuit 34 does not output a brake lock trigger signal.

Then, when the brake is pressed again, the vehicle speed immediately before the brake is pressed is a predetermined value, which is 10 km/h in the example.
Only when it is lower does the arithmetic circuit 34 supply a brake lock trigger signal to the OR gate 40, whereby the self-hold circuit 14 is activated to perform the desired brake lock effect.

FIG. 2 shows an explanation of the operation at such a low vehicle speed. When the foot brake is depressed again at time _t1 , the output 100 of the brake switch 20 switches from "H" to "L". The output 102 of the inverter 24 switches from "L" to "H". Then, the output 104 of the delay circuit 22 switches from "H" to "L" at _t2 after a predetermined delay time T has elapsed. At this time, the vehicle speed immediately before the start of braking indicates the correct vehicle speed because the tire lock has been released, but if this vehicle speed is less than a predetermined value, the comparator 32
The output 106 of is “H”, and as a result,
The arithmetic circuit 34 receives the output 10 of its AND gate 36.
8 is switched from "H" to "L" for the first time at time _t2 after delay time T has elapsed from time _t1 . Therefore,
Output power 108 of AND gate 38 of arithmetic circuit 34
becomes "H" only from time _t1 to time _t2 , and this is supplied to the self-hold circuit 14 as a brake lock trigger signal.

Therefore, even when a tire lock occurs or a tire lock is erroneously detected, if the brake is applied again and the vehicle speed immediately before the braking operation is below a predetermined value, the lock will be resumed regardless of the state where the brake lock is prohibited due to the tire lock. As a result, the electromagnetic brake 10 performs the desired brake locking action.

Incidentally, the device according to the present invention can also be applied to a vehicle braking device of a brake hydraulic pressure containment type.

As described above, according to the present invention, the prohibition of brake lock due to tire lock detection is reliably canceled by reapplying the brake after the vehicle has almost stopped, even when tire lock is canceled by reapplying the brake, or even when tire lock is erroneously detected. Therefore, the brake lock can be quickly resumed, and the brake lock can be effectively utilized. According to the present invention, when a tire lock occurs, it is possible to reliably prohibit brake lock.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing a preferred embodiment of a brake lock device according to the present invention, and FIG. 2 is an explanatory diagram of the operation of the main parts in FIG. 1. 18... Braking operation detection circuit, 20... Foot brake switch, 22... Delay circuit, 26... Vehicle speed delay output circuit, 30... Delay circuit, 32... Comparator, 34...
Arithmetic circuit.

Claims (1)

[Claims] 1. A vehicle brake that has a brake lock control circuit that outputs a brake lock signal that electromagnetically locks the foot brake of a vehicle under predetermined conditions, locks the brake when the vehicle is braking, and prohibits the brake lock when a tire lock occurs. The locking device includes a braking operation detection circuit that detects a braking operation by a foot brake and outputs a short-time braking operation signal, a vehicle speed delay output circuit that outputs a delayed vehicle speed signal delayed by a predetermined time, and a vehicle speed delay output circuit that outputs a delayed vehicle speed signal delayed by a predetermined time. A comparator that compares with a reference value, and detects from the output of the comparator and the brake operation signal that the vehicle speed immediately before the brake operation is below a predetermined value and that the brake has been operated again, and uses the brake lock trigger signal to control the brake lock. 1. A brake locking device for a vehicle, comprising: an arithmetic circuit outputting an output to a circuit, and capable of quickly locking the brakes when a tire lock is released.