JPH065932Y2 - Failure sensor for G sensor for anti-skid control - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an on-off type G sensor used in an anti-skid control device for preventing wheel lock by brake hydraulic pressure control, and a device for informing of its failure. It is a thing.

(Prior Art) During braking of a vehicle, the rotation state of the wheels or the propeller shaft, that is, the deceleration or slip ratio of the wheels is detected, and the brake fluid pressure is adjusted so as to maintain a certain slip ratio according to the detected value. An anti-skid control device for controlling the vehicle to obtain maximum deceleration and lateral stability of the vehicle body is already known.

Here, for example, when the vehicle travels on a road surface with a high friction coefficient μ between the tire and the road surface, that is, on a paved road, anti-skid control for a high μ road is performed and the friction coefficient is When traveling on a low μ road surface, that is, on a snowy road, anti-skid control for low μ roads is performed, and the judgment of high μ roads and low μ roads is provided on the vehicle body. It is performed based on a signal from a G sensor (also referred to as an acceleration / deceleration sensor). As shown in FIG. 5, the G sensor 1 is formed in a casing 2 made of resin or metal, and is formed in the casing 2. The G sensor 1 rises in the front-rear direction of the vehicle (left-right direction in the figure) and is located at the bottom in the approximate center. An inclined groove 2b having a point 2a and the inclined groove 2b
Are arranged along the slanted groove 2b, and one base end is connected to the plus power source 6 and the other end is connected to the controller 15 composed of a microcomputer for controlling anti-skid control, and one end 3b and the other end are connected. Reed switches 3 respectively located in the vicinity of the lowest point 2a in the inclined groove 2b in a non-contact state with the base end 3c, and the inclined groove
It is composed of a mercury ball 4 as a conductive liquid particle enclosed in 2b, and when braking when traveling on a high μ road, the road surface resistance is high, so the deceleration becomes large, and the mercury ball 4 is caused by inertial force. As it rises upward in the slanted groove 2b, the above-mentioned reed switch 3 is released from the energized state. On the other hand, when braking on a low μ road, the deceleration becomes small because the road surface resistance is low and the mercury ball 4 becomes Since it stops at the lowest point 2a in the inclined groove 2b as shown by the solid line, the reed switch 3 is energized. In this way, since the reed switch 3 is turned off during braking when traveling on a high μ road,
Since the G sensor 1 does not energize the controller 15, the reed switch 3 is turned on during braking when traveling on a low μ road, so an on signal is sent from the G sensor 1 to the controller 15 and the road surface condition is reduced. A high μ road or a low μ road is determined based on the presence or absence of a signal, that is, an ON signal. That is, when no output is sent from the G sensor 1 to the controller 15, the high μ road is determined, and when an output is sent to the controller 15, the low μ road is determined. Incidentally, when the determination of the high μ road and the low μ road based on the signal from the G sensor is added, this is as follows.
This is because the deceleration of the vehicle that occurs when the braking force increases until the wheels tend to lock and the antiskid control is performed is governed by the friction coefficient between the wheels and the road surface. That is, the deceleration (signal from the G sensor) generated in the vehicle at the time of shifting to the anti-skid control utilizes a phenomenon that it is low on the low μ road and high on the high μ road. For example, Japanese Patent Publication No. 58-47381. Are known from.

(Problems to be solved by the device) The on / off type G sensor 1 may occasionally have an on failure. This on failure means that the mercury ball 4 is solid lined at the lowest point 2a in the inclined groove 2b. It means that the vehicle stops and does not move as shown in Fig. 6.In such a state, the output is always sent to the controller 15, and even if the vehicle runs on a high μ road, it is judged by the controller 15 that the vehicle runs on a low μ road. As a result, the brake hydraulic pressure is extremely relaxed when braking on a high μ road, resulting in a problem that the braking distance is greatly extended, which is even dangerous. Here, the anti-skid controller is
If a sensor failure alarm device is equipped, the driver can be notified of the failure and the defective G sensor can be replaced, so there is no problem. However, such a failure alarm device for a G sensor has not been available in the past. It was

An object of the present invention is to provide an inexpensive and highly reliable anti-skid control G-sensor failure alarm device for informing a driver of a failure of an on-off type G sensor used in an anti-skid control device. is there.

(Means for Solving the Problems) In order to achieve the above object, the failure alarm device of the anti-skid control G sensor of the present invention supports an on / off type G sensor and one end of the G sensor, and at normal temperature. A shape memory alloy that keeps the G sensor in a horizontal state, tilts the G sensor during heating to release the energized state of the G sensor, and returns to the shape at room temperature after heating, and the vicinity of the shape memory alloy And a heating means for heating the shape memory alloy for a predetermined time when the vehicle is started, and an output signal from the G sensor is received, and when the G sensor is in an energized state at the time of heating, the G A configuration is provided that includes a controller that sends a failure notification signal indicating that the sensor has failed, and failure notification means that notifies the failure of the G sensor when the failure notification signal is received. It

(Operation) According to the present invention, when the vehicle is started, the shape memory alloy locked by the on-off type G sensor is warmed for a predetermined time, and the shape memory alloy tilts the G sensor to make the G sensor conductive. However, if the G sensor has an ON failure, the ON signal is sent to the controller without releasing the energized state of the G sensor. Then, the controller sends a failure notification signal indicating that the G sensor is in failure to the failure notification means, and when the failure notification signal is input to the failure notification means, the failure notification means notifies the failure of the G sensor. I will let the driver know about it. Then, after a lapse of a predetermined time, the shape memory alloy is naturally cooled and the G sensor naturally returns to the horizontal state at room temperature to return the G sensor to the energized state.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an anti-skid control G showing an embodiment of the present invention.
FIG. 2 is a block diagram showing the configuration of a sensor failure alarm device, and FIG. 2 is a schematic configuration diagram of the G sensor and its vicinity in the same device at room temperature. As shown in FIG. On the lower surface of one end 2c of the vehicle in the front-rear direction (left-right direction in the drawing), a rod-shaped shape memory alloy 10 having a base end locked to a fixing plate 12 fixed to a base surface 13 is formed.
, The end of which is locked, while the bottom surface of the other end 2d is
A leg that is rotatably supported by a hinge 14 provided on 13
11, the end of which is fixed, and the shape memory alloy 10
Means that the mercury bulb 4 enclosed in the inclined groove 2b is
When tilted with the fulcrum as the fulcrum, it is stored at a high temperature so that the length is equal to or longer than the length when moving from the vicinity including the lowest point 2a toward the end of the inclined groove 2b. It has been compressed and deformed so that it has a length equal to the horizontal state. Since the G sensor 1 is the same as the conventional G sensor described in FIG. 5, the description thereof is omitted here, and its output is input to the controller 5. A coil heater 49, one end of which is grounded to the base surface 13, is arranged in the vicinity of the shape memory alloy 10 in the longitudinal direction, and the other end of the coil heater 49 includes a timer circuit 48 and an ignition switch 45. It is connected to the positive power source 19 via. The timer circuit 48 is connected to a power source (not shown), and in response to an operation signal from the controller 5 after the ignition switch 45 is turned on, a current is supplied to the coil heater 49 for a certain period of time. Here, the coil heater 49 and the timer circuit 48 constitute the heating means 70.

Because it is configured in this way, the ignition switch
When the operation signal is sent from the controller 5 after turning on the 45, the electric current starts to flow through the coil heater 49 and the shape memory alloy 10 is heated. Therefore, as shown in FIG. The memory alloy 10 extends to the stored length at high temperature, and the G sensor 1 is rotated about the hinge 14 and tilted. Then, as shown in the figure, the mercury ball 4 moves from the vicinity including the lowest point 2a toward the end of the inclined groove 2b, so that the G sensor 1 is de-energized and sent to the controller 5. The signal is blocked. Then, after a lapse of a certain time, the timer circuit 48 is cut off.
Then, the energization state of the coil heater 49 is released, and the shape memory alloy 10 is naturally cooled. Therefore, as shown in FIG. 2, the shape memory alloy 10 returns to the compressed and deformed length at room temperature, and the G sensor 1 Level. Then, the G sensor 1 returns to the energized state, and the ON signal is sent to the controller 5. Thus, in the present invention, G
Since the shape memory alloy is used for tilting and returning the sensor 1 without using an actuator such as a solenoid or a motor, the shape memory alloy is very inexpensive. There is no failure that the G sensor 1 fails when it tilts and does not move as it is, and it does not return to its original state. After heating, it naturally returns to its normal temperature shape by natural cooling. There is no possibility that the G sensor 1 cannot be returned to its original state and cannot be used due to a mechanical failure of the mechanism for returning or returning, and the reliability is high. It goes without saying that the reed switch 3 connected to the plus power source 6 and the controller 5 is flexible in the middle thereof.

Here, in addition to the ON / OFF signal from the G sensor 1, the controller 5 senses the operation of the wheel speed sensor 30 and the brake pedal, which can detect the speed of each wheel, as shown in FIG. A fail lamp, which is a failure notification means, receives a signal from the brake switch 40 and an ignition switch 45 that turns the vehicle on and off and sends a drive signal to each modulator 50 that controls the brake fluid pressure.
A failure notification signal is sent to 46, and an operation signal is sent to the timer circuit 48. The controller 5 sends an ON signal from the well-known anti-skid control circuit 51 and the G sensor 1 when the shape memory alloy 10 is heated. When receiving an OFF signal from the G sensor 1 when receiving and when a predetermined time has elapsed after heating the shape memory alloy 10, a failure notification signal is sent to the fail lamp 46 as a failure of the G sensor 1. A microcomputer configured to achieve the same function as that of the G sensor failure detection circuit 52 that shuts off the antiskid control circuit 51 that controls the antiskid control system so that various controls are not performed. Further, a program capable of achieving the above functions is written in the ROM in the controller 5, and each set value and data table are stored and processed. . The flowchart of the program written in the ROM is shown in FIG.

The operation of the failure alarm device will be described below according to the program.

When the program starts, first in step 1, the ignition switch 45 is turned on and in step 2
In step 2, the timer circuit 48 is activated to start heating the coil heater 49, and the process proceeds to step 3. In step 3, it is determined whether or not a predetermined time has elapsed after heating the coil heater 49, and the predetermined value is determined. If the time has not elapsed, the process returns to step 3, and the same operation is repeated until the predetermined time elapses, while if the predetermined time has elapsed, the process advances to step 4. Here, the predetermined time is approximately equal to the time required for the shape memory alloy 10 to have a memorized shape at high temperature. And in step 4,
It is determined whether the G sensor 1 is off, and if it is off,
That is, the G sensor 1 is inclined as shown in FIG.
If the mercury bulb travels along the groove and cuts off electricity, step 8
On the other hand, if the G sensor 1 remains on, the G sensor 1 may have an ON failure or the like, and the process proceeds to step 5. In step 5, whether or not the counter is equal to or more than a predetermined value, that is, an arbitrary time has elapsed Whether or not it is determined.
If the counter is equal to or greater than the predetermined value, the G sensor 1
Has caused an on-state failure or the like, and proceeds to step 6 as a defect. In step 6, the anti-skid control system is shut off and the fail lamp 46 is flashed so as not to perform unintended control thereafter. In this way, when the vehicle is started, the ON failure of the G sensor 1 is checked, and if there is a failure, the fail lamp 46 blinks to notify the driver of the failure. You can take action quickly. On the other hand, if the counter has not reached the predetermined value or more, the process proceeds to step 7, the counter is incremented in step 7, and then the process returns to step 4. Then, if the G sensor 1 is still on, the process proceeds to step 5, and the same operation is repeated. On the other hand, if the G sensor 1 is turned off, it is determined that the G sensor 1 is in the normal state and the step 8 is performed. Go to. Then, in step 8, the heater 49 is shut off, and the process proceeds to step 9. In step 9, it is determined whether or not the set time has elapsed after shutting off the heater 49. If not, the process returns to step 9 to set the set time. The same operation is repeated until the time elapses, and when the time elapses, the process proceeds to step 10. Here, this set time is approximately equal to the time for the shape memory alloy 10 to naturally cool and return to the shape at room temperature. Then, in step 10, it is judged whether or not the G sensor 1 is on, and if it is on,
That is, when the G sensor 1 returns to the horizontal state at room temperature as shown in FIG. 2 and the mercury ball 4 returns to the lowest point 2a and the G sensor 1 is energized, the G sensor 1 is normally operated. Then, the anti-skid control is executed in step 11, and when it is off, the G sensor 1 has not returned to the normal temperature state, that is, the base surface 13 and the G sensor 1 If there is something abnormal such as something is sandwiched between and the shape memory alloy 10 is still stretched, proceed to step 12, and in step 12, whether the counter is equal to or greater than a predetermined value, that is, after that It is determined whether or not the time has passed. If the counter is equal to or greater than the predetermined value, something is sandwiched between the G sensor 1 and the base surface 13, and the shape memory alloy 10 remains stretched so that the G
Assuming that the sensor 1 is defective, proceed to step 6,
In step 6, the anti-skid control system is shut off and the fail lamp 46 is flashed so as to prevent unintended control. Thus, even when the shape memory alloy 10 is restored when the vehicle is started, the G sensor 1
The failure is checked, and if there is a failure, the fail lamp 46 blinks to notify the driver of the failure as before, so that measures such as replacement can be taken as soon as possible. It has become. On the other hand, if the counter has not reached the predetermined value or more, the process proceeds to step 13, the counter is incremented in step 13, and then the process returns to step 10. Then, if the G sensor 1 is still off, the process proceeds to step 12, and the same operation is repeated. On the other hand, if the G sensor 1 is turned on, it is assumed that the G sensor 1 has returned to the normal state and the step 11 Then, in step 11, anti-skid control is executed.

In the above embodiment, the driver is informed of the failure of the G sensor by blinking the fail lamp. However, the fail lamp may be turned on, which is the same as the turning on of the fail lamp of the known fail-safe circuit. If it is confusing, it is possible to newly provide a failure alarm lamp for the G sensor so as to turn on or blink it, and further, it may be notified by a failure notification means such as a buzzer.

(Effect) As described above, according to the present invention, when the G sensor used in the anti-skid control device fails, the driver is informed of the failure, so that the failed G sensor can be replaced, and safety is improved. The sex can be further enhanced. Further, since a shape memory alloy is used for the failure alarm device, and the G sensor is tilted and returned by this shape memory alloy, the reliability of the failure alarm device is enhanced and the device is inexpensive.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a failure alarm device for an anti-skid control G sensor according to an embodiment of the present invention.
FIG. 3 is a schematic configuration diagram of the G sensor in the same apparatus at room temperature and its vicinity, FIG. 3 is a schematic diagram of the G sensor when the shape memory alloy in the same apparatus is heated, and FIG. 4 is in FIG. 5 is a flow chart of a program stored in the controller of FIG. 5, and FIG. 5 is a schematic configuration diagram of a G sensor showing a conventional technique. 1 …… G sensor for anti-skid control, 2a …… bottom point,
2b ... Inclined groove, 2c ... One end of G sensor, 3 ... Reed switch, 4 ... Mercury bulb, 5,15 ... Controller, 10 ...
… Shape memory alloy, 45 …… Ignition switch, 46 ……
Failure notification means, 48 ... Timer circuit, 49 ... Heater, 70 ...
… Heating means.

Claims (1)

[Scope of utility model registration request] 1. A sloped groove that rises in the front-rear direction of a vehicle, and a sloped groove that is disposed along the sloped groove and that is close to each other in the sloped groove and that includes the lowest point. The reed switch that is in contact with the reed switch is enclosed in the inclined groove, and when the acceleration / deceleration is high, the reed switch is de-energized by inertial force to rise upward in the inclined groove. An anti-skid control G sensor consisting of a mercury ball for stopping the reed switch and energizing the reed switch and one end of the G sensor are supported to keep the G sensor horizontal at room temperature. A shape memory alloy that tilts the G sensor during heating to release the energized state of the G sensor and returns to the shape at room temperature after heating is finished; A heating means for heating the shape memory alloy for a predetermined time when the vehicle is started and an output signal from the G sensor, and when the G sensor is in an energized state at the time of heating, the G sensor fails. The anti-skid control G having a controller that sends a failure notification signal and failure notification means that notifies the failure of the G sensor when the failure notification signal is received.
Sensor failure alarm device.