JPH0349762B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to vehicle height control, and in particular, detects the height between an axle and a vehicle body frame with a vehicle height detector,
The present invention relates to a vehicle height adjustment device that controls the fluid pressure of a suspension system in correspondence with the detected vehicle height to set the vehicle height within a target range. In this type of vehicle height adjustment, for example, as disclosed in U.S. Pat. The signal is processed to obtain a signal that energizes the vehicle height adjustment drive system, which is then applied to the drive system to lower the fluid pressure of the suspension system when the vehicle height is "high" and to lower the fluid pressure when the vehicle height is "low". At certain times, the fluid pressure is increased. Therefore, in order to prevent repeated fluid pressure reduction operations when the detected vehicle height vibrates near the boundary between "medium" and "high",
In order to prevent repeated fluid pressure raising operations when vibrating near the boundary between and "low", the vehicle height adjustment control circuit generally includes a vehicle height "high" signal processing system and a vehicle height "low" signal processing system. Each system includes one set of rise delay circuits, and in order to prevent continuous compressor drive when the vehicle weight is large and the vehicle height can hardly be raised, an additional delay circuit is provided. In order to prevent continuous fluid pressure release (relief valve opening) when the pressure does not drop below this level, the vehicle height adjustment circuit includes a vehicle height "high" signal processing system and a vehicle height "low" signal processing system.
Each signal processing system includes a set of energization time circuits. However, since this type of display is used in a harsh environment with high temperatures (or low temperatures) and many vibrations, it is likely that connectors will come off, wires will break, shorts, active elements will fail, or drive devices will break down. For example, if an abnormality occurs in a detector that detects the vehicle height, an abnormal situation may occur in which vehicle height raising control and vehicle height lowering control are performed simultaneously. Conventional vehicle height control does not take measures against abnormalities, so the driver often does not notice that an abnormality has occurred. Become. Also, although it is not a vehicle height adjustment device, for example,
No. 50-34318 discloses detecting an abnormality in a gyroscope, which is a sensor, and displaying the abnormality. However, with this type of conventional technology, it is not possible to detect an uncontrollable state such as a failure in something other than a sensor or a case where a vehicle height adjustment device comes off the wheel, nor can it display an abnormality. The present invention provides a vehicle that quickly detects and notifies when vehicle height control becomes impossible, even if a failure occurs in either the vehicle height detector or the drive means, or even if the wheels come off. Aims to provide highly adjustable display. In order to achieve the above object, in the present invention,
A vehicle height detector that generates a vehicle height signal corresponding to the distance between the vehicle wheel axle and the vehicle body; A drive means that controls the vehicle height up and down; A control circuit that generates a vehicle height adjustment signal to be applied to the drive means in response to when the vehicle is running; a first abnormality detection means that detects and outputs an abnormality signal; a second abnormality detection means that detects an uncontrollable state and outputs an abnormality signal when the time for energizing the drive means exceeds a predetermined time limit; third abnormality detection means for detecting whether or not there is a failure in the vehicle height detector based on the states of a plurality of signals output from the detector and outputting an abnormality signal; the first, second and third abnormality detection means; Abnormality displaying means for displaying an abnormality when at least one abnormality signal is detected among the means; and after the abnormality displaying means detects an abnormality signal from the second abnormality detection means and displays an abnormality; When an output signal entering the target vehicle height region is detected from the vehicle height detector and no abnormality detection signals from the first and third abnormality detection means are detected, an output signal from the second abnormality detection means is detected. An abnormality display canceling means is provided for stopping the output of the abnormality signal and canceling the abnormality display of the abnormality display means. According to the present invention, if (1) the detected vehicle height does not change even if the vehicle height is adjusted by derailing or jacking up the vehicle body, (2) the actual vehicle height is within the target vehicle height range. However, if the vehicle height detector continuously outputs a vehicle height signal indicating a state higher than the target vehicle height range, (3) the actual vehicle height may not be the same even if it is activated due to a failure of the drive means. In any case, such as when the drive means is no longer lowered, the state in which the drive means is energized continues for a long time, and when that time exceeds a predetermined time limit, the control circuit detects an uncontrollable state. When an uncontrollable condition is detected, energization of the drive means is prohibited, and the abnormality is displayed by the abnormality display means. The uncontrollable detection state is maintained until the detected vehicle height returns to the target vehicle height. [Example] Hereinafter, an example of the present invention will be described with reference to the drawings. First, a vehicle height detector 100 according to an embodiment will be explained. As shown in FIG.
One end of a link 20 is connected to the rotating shaft, and the other end of the link 20 is connected to the outer case of the differential gear 30. 40 is an axle. A cross-sectional view of the vehicle height detector 100 is shown in FIG. 1b. In the vehicle height detector 100, a light shielding plate 105 having an arcuate fold 104 is fixed to the tip of a rotating shaft 103, and a link 20 is fixed to the other end. A printed circuit board 107 is fixed to the base 106, and a photo sensor 10 is attached to this printed circuit board 107.
1 and 102 are fixed. C- in Figure 1b
The C-line sectional views are shown in Figure 1c, Figure 1d, and Figure 1.
Shown in Figure e. Figure 1c shows a state where the vehicle height is high,
FIG. 1d shows a state where the vehicle height is medium, and FIG. 1e shows a state where the vehicle height is low. Photo sensor 101,
Each of numerals 102 is composed of a light emitting diode and a phototransistor, and a fold 104 of a light shielding plate 105 blocks light from the former to the latter. FIG. 2 shows an embodiment of vehicle height adjustment that is connected to the vehicle height detector 100 and controls the opening and closing of a relief valve 240 for releasing air pressure from the suspension system 400 and a relay 303 for energizing the compressor 302. Control unit CCU is shown. This vehicle height control device CCU
is the photo sensor 101,1 of the vehicle height detector 100
02, a timer 220, amplifiers AMP1 and AMP2 that control the drive means 500, and drive system activation gate means 230.
Means 210 is in this embodiment a Noah gate NOR
1, and produces the output shown in Table 1 below depending on the vehicle height.

[Table] This is the starting signal.
The timer 220 includes a first counter CO1, an AND gate, AND1, an inverter NOT1, and a second counter CO1.
It consists of a counter CO2 and a NOR gate NOR2 used as a timed output gate. Counter CO1 is cleared when output c of NOR gate NOR1 is H, and when c is L, inverter NOT1
When the output of the clock pulse is H (high level "1"), clock pulses are counted, and when a predetermined number of clock pulses are counted, the output terminal _Q1 is set to H. When _Q1 becomes H, the output of inverter NOT1 is inverted to L, so ENABLE of counter CO1 becomes L and counting stops, the output of NOR gate NOR2 becomes H, and counter CO2 is cleared and starts counting. Start. When the counter CO2 counts a predetermined number, the output terminal _Q2 becomes H, the output of the NOR gate NOR2 becomes L, the AND gate AND1 turns off, and the counter CO2 stops counting up. Output H of NOR gate NOR2
is the “vehicle height adjustment drive system energizing instruction level signal” and is applied to the drive system energizing gate means 230. The gate means 230 is composed of AND gates AND2 and AND3 in this embodiment,
The vehicle height “high” detection signal a of the photo sensor 101 and the activation instruction signal of NOR2 are applied to AND2,
The vehicle height “low” detection signal b of the photo sensor 102 and the energization instruction signal of NOR2 are applied to AND3,
AND2 and AND3 produce an H output when the two inputs are H, that is, a relief valve 240 opening energizing signal (AND2) and a drive command signal (AND3) to the compressor 302.
Apply to AMP1 and AMP2. If the vehicle height is currently "medium", the outputs a and b of the photo sensors 101 and 102 are both L, so
When the output c of NOR1 is H, the counter CO1 is cleared, and when its _Q1 output is L, the inverter NOT1
The output of is H. Therefore, the count enable given to CO1 is H which indicates that counting is possible.
Also, the counter CO2 is cleared by the H output of NOT1, and its _Q2 output is L. Since the H of NOT1 is applied to the NOR gate NOR2, its output is L, and the AND gate AND1~
AND3 is all off, the relief valve 240 is closed, and the relay 303 is open (compressor 302 is stopped). When the vehicle height becomes high, a=H, b=L
Therefore, the output c of the NOR gate NOR1 becomes L and the counter CO1 starts counting up.
After that, when the vehicle height becomes the same, a=L, b=L, and the counter CO1 is cleared. If the vehicle height remains high, the counter CO1 continues to count up and its output terminal _Q1 becomes H (first time period _t1 ). Then, the output of NOT1 changes to L, and the output of NOR2 changes to H.
, the relief valve 240 opens, the air pressure of the suspension system 400 begins to decrease, and the AND gate AND1 turns on, the CO2 count enable changes to countable H, the CO1 count enable changes to countable L, and the counter CO1
stops counting and counter CO2 counts up. After that, the vehicle height returns to inside a
=L, b=L, the counter CO1 is cleared, the output of NOT1 becomes H and CO2 is also cleared, the output of the NOR gate NOR2 becomes L, the AND gates AND1 and AND2 are turned off, and the relief valve 240 is closed. Return to In other words, even after the relief valve 240 is opened, the relief valve 240 is immediately closed when the vehicle height returns to the inside. If the vehicle height remains high, counter CO2 sets the output of _Q2 to H after a predetermined time (second time limit t ₂ ), thereby setting the output of NOR gate NOR2 to L and turning off AND gates AND1 and AND2 for relief. Return valve 240 closed. If the vehicle height is still high, the relief valve 240 will no longer open. 250 is a first abnormality detection circuit, which is composed of two circuits: a circuit consisting of a transistor Tr ₁ , an exclusive OR EXR1, and a resistor, and a circuit consisting of a transistor Tr ₂ , an exclusive OR EXR2, and a resistor; The former detects an abnormality in the amplifier AMP1 and the relief valve (electromagnetic valve) 240, and the latter detects an abnormality in the amplifier AMP2 and the relay 303. Specifically, the abnormality detected by the former is () Disconnection of the solenoid of valve 240 () Solenoid short of valve 240 () Amplifier
AMP1 output shot and ()amplifier AMP
1 output is open, and the signals d, e, f in each state are as shown in Table 2 below.

[Table] The abnormality of () and () is when d is L,
Abnormalities in () and () are detected when d is H. The abnormalities detected by the latter are () disconnection of the coil of the relay 303, () the coil short of the relay 303, () the output short of the amplifier AMP2, and () the output open of the amplifier AMP2, and the states g, h, and i is as shown in Table 3, and abnormalities in () and () are detected when g is L, and abnormalities in () and () are detected when g is H.

[Table] Counter CO2 also serves as a second abnormality detection circuit, and when it continues counting for a predetermined time or longer, its output _Q2 becomes H, and therefore the abnormality detection signal j
becomes H. AND gate AND4 is the third abnormality detection circuit. Referring to Table 1 above, the signals (a, b) from the vehicle height detector 100 are (H, L),
Only three combinations of (L, L) and (L, H) are allowed, and the state of (H, H) is the state of the vehicle height detector 100.
Indicates that an abnormality has occurred. When (a, b) becomes (H, H), the output signal of the AND gate AND4, that is, the abnormality detection signal k becomes H. 260 is a display circuit (display means), which is composed of OR gates OR1, OR4, an AND gate AND6, a transistor _Tr3 , and a light bulb LP. Normally, the output of OR gate OR1 is L and the AND gate
The output of AND6 is L. On the other hand, if vehicle height raising control or vehicle height lowering control is performed, the Noah Gate
The output of NOR2 becomes H, the output of OR gate OR4 becomes H, transistor _Tr3 is turned on, and the light bulb LP is turned on.
lights up. When vehicle height control is not performed, the output of the NOR gate NOR2 is L, and under normal conditions, the transistor _Tr3 is off and the light bulb is off. If an abnormality is detected in at least one of the abnormality detection circuits, the output of OR gate OR1 becomes H, AND gate AND6 is opened, and the divided clock pulse from the clock generator passes through AND gate AND6 and OR gate OR4. and is applied to the base of transistor _Tr3 . Therefore, transistor Tr ₃ is intermittently turned on and the light bulb is turned on.
LP flashes to indicate that an abnormality has occurred. For example, when coming off the wheels or jacking up the vehicle body, the detected vehicle height may not change even if the vehicle height is adjusted, even though it is not a real abnormality, and there is a risk that unnecessary vehicle height adjustments will be made over a long period of time. Therefore, this device detects this as a pseudo-out-of-control condition and displays an abnormality. In other words, due to wheel derailment or jack up, the detected vehicle height becomes the target vehicle height "medium".
When the value is off, counter CO1 starts counting as described above, and when the count reaches a predetermined value,
Counter CO2, which is the second abnormality detection circuit, starts counting. When the count number of CR2 reaches a predetermined value, that is, if the detected vehicle height remains out of the "medium" range for a long time even though the vehicle height is being adjusted, _Q2 of CO2 becomes H, i.e. An abnormality signal is output, and the display circuit 260 displays the abnormality. however,
In the case of a pseudo-uncontrollable state, the abnormality display is automatically canceled when the cause disappears, that is, when the vehicle exits from the derailed state or when the jack-up ends. That is, when the counter CO2 outputs an abnormal signal, the output of the NOR gate NOR2 becomes L, and the AND gate AND1, which is an abnormality display canceling means, stops inputting the clock signal to the counter CO2, and the abnormality detection state is maintained. , when the vehicle height returns to "medium" due to the termination of the jack up, etc.
The output signal c of the NOR gate NOR1 becomes H, the counter CO1 is cleared, and the _Q1 of CO1 becomes L, thereby clearing CO2 and
_Q2 is L, meaning the abnormal signal is released. If both the first abnormality detection circuit 250 and the third abnormality detection circuit AND4 do not output abnormality signals at this time,
Since the output of the OR gate OR1 becomes L, the display state of the display circuit 260 is automatically canceled. Therefore, in the case of a pseudo-uncontrollable state such as during a jack-up, an abnormality display is displayed, but the abnormality display is automatically canceled without the driver performing any special switch operation. FIG. 3 shows another embodiment of the invention. In this case, the maximum time (t ₃ ) for biasing the vehicle height up is set to be longer than the maximum time (t ₂ ) for biasing the vehicle height down.
That is, in the timer 220, the timer output gate is activated.
As two sets of NOR2 and NOR3, the input terminal is the Q ₃ (t ₃ time period) output terminal of counter CO2 and Q ₂ (t ₂ time period).
Connect to the output end and gate the outputs respectively.
Inverter NOT2 and OR gate OR1 allow AND gate AND1 to be turned on only when the vehicle height is high or low, so that it is divided into AND2 and AND3. In addition, the second abnormality detection circuit adds an AND gate AND5 and an OR gate OR3,
The signals from the outputs Q ₂ and Q ₃ of the counter CO2 are selected in response to vehicle height lowering and vehicle height raising and are used as the abnormality detection signal j. The display circuit 260' uses the OR gate OR4 as a three-input type, and the AND gate.
It is connected to the outputs of AND2 and AND3. The rest of the structure is the same as the embodiment shown in FIG. Other embodiments of the display circuit 260 are shown in FIGS. 4a, 4b, and 4c, respectively. In FIG. 4a, a light bulb is made to blink when controlling the vehicle height, and is turned on when an abnormality occurs. Figure 4b shows a light bulb.
There are two lights, LPa and LPb, and LPb is turned on when controlling the vehicle height, and LPa is turned on when an abnormality occurs. Fig. 4c shows a configuration in which a light emitting diode LED whose emitted light color changes depending on the bias current is used to change the display color during vehicle height control and when an abnormality occurs.
Therefore, resistors _R1 and _R2 with different resistance values are used. As described above, according to the present invention, even if a failure occurs in the vehicle height detector, the control circuit, the drive means, etc., or even if the wheels come off or the vehicle body is jacked up, it is possible to prevent the vehicle from becoming uncontrollable. It is possible to detect this as an abnormality, prohibit vehicle height adjustment, and display an abnormality display. Since the uncontrollable detection state is maintained until the vehicle height returns to the target range, there is no risk of the display being overlooked. Furthermore, in the case of a pseudo-uncontrollable state such as during a jack-up, the abnormality display is automatically canceled when the jack-up ends, so there is no need to perform a special switch operation, resulting in good operability.

[Brief explanation of drawings]

FIG. 1a is a side view showing the mounting state of the vehicle height detector, and FIG. 1b is a longitudinal sectional view of the vehicle height detector. Figures 1c, 1d and 1e are C of Figure 1b.
-C line sectional views showing different vehicle height states. FIGS. 2 and 3 are circuit diagrams each showing an embodiment of the present invention. Figure 4a,
FIGS. 4b and 4c are circuit diagrams each showing an embodiment of the display means. 10: Vehicle frame, 20: Link, 30: Differential gear, 40: Axle, 100: Vehicle height detector, 101, 102: Photo sensor, 10
3: rotating shaft, 106: base, 107: printed circuit board, 210: means for generating a delay time start signal,
220: Timing device, 230: Drive system energizing gate means, 240: Relief valve, 250: First abnormality detection circuit, 260, 260': Display circuit (abnormality display means), 301: Motor, 302: Compressor, 303 : Relay, 400: Suspension device, 50
0: Driving means, AND1 to AND6: AND gate, AND1: (Abnormality display cancellation means), NOR1 to
NOR3: Noah gate, AND4: Third abnormality detection circuit, CO2: Counter (counter means), OR1
~OR4: OR gate, EXR1, EXR2: Exclusive OR gate, NOT1, NOT2: Inverter, LP, LPa, LPb: Light bulb, LED: Light emitting diode, AMP1, AMP2: Amplifier,
CCU: Control circuit.

Claims (1)

[Claims] 1 Vehicle height detector that generates a vehicle height signal corresponding to the distance between the vehicle wheel axle and the vehicle body; Drive means that performs vertical control of vehicle height; When the signal output from the vehicle height detector deviates from the target vehicle height range A control circuit that generates a vehicle height adjustment signal to be applied to the drive means in response to when the drive means is running; detects whether or not there is a failure in the drive means and the control circuit from the state of signals on both the input and output sides of the control circuit. a first abnormality detection means for detecting an abnormality signal and outputting an abnormality signal; a second abnormality detection means for detecting an uncontrollable state and outputting an abnormality signal when the time for energizing the drive means exceeds a predetermined time limit; A third device that detects whether or not there is a failure in the vehicle height detector based on the states of a plurality of signals output from the height detector and outputs an abnormal signal.
abnormality detection means; abnormality display means for displaying an abnormality when detecting at least one abnormality signal among the first, second and third abnormality detection means; and an abnormality signal from the second abnormality detection means. is detected and the abnormality display means displays an abnormality, an output signal entering the target vehicle height region is detected from the vehicle height detector, and an output signal from the first and third abnormality detection means is detected. A vehicle height characterized by comprising abnormality display canceling means for stopping the output of the abnormality signal from the second abnormality detection means and canceling the abnormality display of the abnormality display means when the abnormality detection signal is not detected. Adjustment device.