JPS6311167B2 - - 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 or the like and a vehicle body frame using a vehicle height detector, and controls the fluid pressure of a suspension system in correspondence with the detected vehicle height to adjust the vehicle height. The present invention relates to a vehicle height adjustment device that adjusts the vehicle height to a predetermined 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, and this signal is given to the drive system, and when the vehicle height is "high" in the drive system, the fluid pressure of the suspension system is lowered and the vehicle height is set to "low". When , the fluid pressure is increased. By the way, in this type of vehicle height adjustment, there are cases where it is desired to change the target vehicle height between "high" and "low" vehicle heights. For example, on well-maintained roads such as expressways, the target vehicle height is lowered to improve vehicle driving stability, and on unpaved roads, the vehicle height is lowered to avoid contact between the vehicle body and the ground. This is a case where the vehicle height is changed depending on the road conditions, such as raising the target vehicle height and raising the vehicle height. In order to change the target vehicle height, conventionally, a plurality of vehicle height detectors or a number of detection means are provided within the vehicle height detector, and signals from these vehicle height detectors or detection means are selected. A circuit was installed to determine the target vehicle height using the selected signal. However, with such a configuration, the gate circuit for selecting the signal and the like becomes complicated, which increases the cost and increases the power consumption due to the increase in the circuit and the detection means. One object of the present invention is to provide a low-cost vehicle height adjustment device that allows changing the target vehicle height with a small number of circuit elements, and another object is to provide an inexpensive vehicle height adjustment device that does not involve an increase in power consumption. To provide a vehicle height adjustment device that allows a target vehicle height to be changed by means. In order to achieve the above object, in the present invention,
The vehicle height detector is provided with a plurality of detection means each having a light emitting element and a photoelectric conversion element, and the energizing current of the light emitting element provided in each detection means is controlled by a switch means for instructing a change in the set vehicle height. By turning the sensor on/off, the detection function of the detection means is selectively turned on/off. According to this, only the detection means whose detection function is in the ON state outputs a signal, so even when a large number of detection means are used, it is difficult to select some of the signals outputted by them. No signal selection circuit is required. Further, in a preferred embodiment of the present invention, in order to reduce the number of detection means to reduce costs and to improve the precision of vehicle height adjustment, the signal is set to H in accordance with the binary signal output from one detection means. (high level), the vehicle height is adjusted so that it becomes L (low level), and when that signal is L, the vehicle height is adjusted so that it becomes H. These vehicle height adjustments are made based on that signal. Stop when it reverses from H to L or from L to H. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the installation of the vehicle height detector of the present invention. The vehicle height detector 100 is fixed to the vehicle body frame 10, and one end of a link 20 is connected to its 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. In the vehicle height detector 100, an arc-shaped fold 1 is provided at the tip of the rotating shaft 103.
A light shielding plate 105 formed with 04 is fixed,
A link 20 is fixed to the other end. base 10
A printed circuit board 107 is fixed to 6, and a photo sensor 102 and 1 are connected to this printed circuit board 107.
02 is fixed. 2b, 2c, 2d and 2.
Shown in Figure e. In this embodiment, the target vehicle height is switched between "high" and "low"; however, in the "low" setting, the vehicle height in Fig. 2b is "low" and the vehicle height in Fig. 2d is "low".
2e and 2e show the vehicle height "high", and FIG. 2c shows the state of the boundary between the vehicle heights "high" and "low", that is, the state of the target vehicle height. Also, in the “high” setting,
FIGS. 2b and 2c show the vehicle height "low", FIG. 2e shows the vehicle height "high", and FIG. 2d shows the boundary between the "high" and "low" vehicle heights, that is, the state of the target vehicle height. Photo sensors (detection means) 101 and 102 are the third a
As shown in the figure, it is composed of a light emitting diode and a phototransistor, and a light shielding plate 105 blocks light from the former to the latter. FIG. 3a is a circuit diagram of a vehicle height adjusting device using the vehicle height detector 100, and FIGS. 3b and 3c are time charts showing the operation of the device. First, the configuration of the apparatus will be explained with reference to FIG. 3a. 400 is a vehicle height adjustment drive device, which is connected to a vehicle height adjustment control device 200 that controls it. On the input side of the vehicle height adjustment control device 200, photo sensors 101 and 10 of the vehicle height detector 100 are provided.
2. Door switch that issues vehicle height adjustment instruction signal a
Warning lamp WL and photo sensor 101, 10 that turn on and off in response to the operation of SW ₁ and SW ₁
Monostable multivibrators MM ₁ , MM _{2 ,} etc. are connected to a vehicle height changeover switch SW ₂ that turns on one detection function and turns off the other detection function. The vehicle height adjustment control device 200 includes a clock pulse generator 210, counters CO ₁ to CO ₃ , AND gates AN ₁ , NAND gates NA ₁ to _{NA 7} , and an inverter.
IN~ _IN4 , diode _D1 , amplifier _AMP1 and
Consists of AMP ₂ . Terminal CLK of counters CO ₁ to CO ₃ is clock input, CLR is clear input,
CE is count enable, Q ₂ and Q ₃ are count outputs, CLR is cleared when H, and count is enabled when CE is H. The state of Q ₂ terminal changes every 4 counts of clock pulse (divided by 8). The state of the _Q3 terminal changes every 8 clock pulse counts (divided by 16). The vehicle height adjustment drive device 400 includes a suspension shock absorber 401, a dryer 450,
It is composed of an exhaust valve (valve means) 410, a compressor (pressure source) 420, a motor 430, and a relay 440. Exhaust valve 410 closes when it is not likely to open when its solenoid is energized.
Relay 440 is a normally open type whose contacts close when its coil is energized. Door switch SW ₁ has a contact that closes when each of the four doors opens, and a contact that opens when those doors close. Monostable multivibrator MM ₁ ,
The output of MM ₂ is always H, and when the level at the input terminal rises, it is triggered and outputs an L pulse at the output terminal. Next, the operation will be explained with reference to FIG. 3b. When the vehicle is running and all doors are closed,
Door switch SW ₁ opens all contacts and sets vehicle height adjustment instruction signal a to H. At this time, Nand Gate
The output of NA ₇ becomes L, clearing of counter CO ₁ is canceled, and the Q ₂ end of CO ₁ and Q ₃ at the previous count
The state in which the end becomes H and counting is prohibited (CE is L) is maintained in the counter _CO1 . The output of NAND gate NA ₁ becomes L, and the NAND gate
Let the output of NA ₂ be H. Further, the output terminals _Q3 of the counters _CO2 and _CO3 are always at L, and the outputs of the inverters _IN3 and _IN4 are set at H. As a result, the outputs of NAND gates NA ₃ and NA ₅ become L, the outputs of NAND gates NA ₄ and NA ₆ become H, and counters CO ₂ and CO ₃ are cleared. In this state, the output terminals Q ₃ of the counters CO ₂ and CO ₃ are at L, so the exhaust valve 410 and the relay 440 are deenergized and the vehicle height is not adjusted. When even one door is opened, such as when someone is getting on or off, the corresponding contact of door switch SW ₁ closes, setting the vehicle height adjustment instruction signal a to L, and also turning on the warning lamp.
Turn on WL. This causes the output terminal of the NAND gate NA ₇ to become H, clearing the counter CO ₁ , and setting the output terminals Q ₂ and Q ₃ to L, thereby setting the output of the NAND gate NA ₁ to H. At this time, since the signal a is L, the output of the NAND gate _NA2 remains at H as before, the states of other circuits connected to it do not change, and the vehicle height is not adjusted. When people have finished getting on and off the vehicle and all doors have been closed, the vehicle height adjustment instruction signal a
is inverted again to H, the output of NAND gate _NA7 is set to L, and the counter _CO1 is cleared, so that the counter _CO1 starts counting clock pulses. At this time, since the output terminals Q ₂ and Q ₃ are L, the output of the NAND gate NA ₁ becomes H, and since the signal a is H, the output of the NAND gate NA ₂ becomes L, and the outputs of the NAND gates NA ₃ and NA ₅ become H. Here, if the contact of vehicle height selector switch SW ₂ is connected to the "high" side, transistor Q ₁ turns on Q ₂
is turned off, current flows through the light emitting diode of photo sensor 101, but no current flows through the light emitting diode of photo sensor 102. Then, the light emitting diode of the photo sensor 102 does not emit light, the photo transistor 102 is turned off, and the output of the photo sensor 102 becomes H regardless of the vehicle height. Here, when the vehicle height is "high" (the state shown in Fig. 2e), the photo sensor 101 is shielded from light and its output becomes H, and the output of the AND gate AN ₁ is set to H, the output of the NAND gate NA ₄ is set to L, and the counter CO ₂ Clear the . In addition, at this time, the output of inverter IN ₂ becomes L and becomes a NAND gate.
The output of NA ₆ remains high and CO ₃ remains cleared. Now counters CO ₁ and CO ₂ start counting at the same time. When 8 pulses have been counted from the start of counting, Q ₃ of CO ₂ becomes H, the output of inverter IN ₃ is set to L, inhibiting counting of CO ₂ , and Q ₃ is held at H. This energizes the solenoid of the exhaust valve 410 via the amplifier AMP ₁ , which opens the exhaust valve and lowers the vehicle height. When the vehicle height is lowered in this manner, the vehicle height gradually decreases, and the state of the vehicle height detector 100 changes from the state shown in FIG. 2e to the state shown in FIG. 2d. When the photo sensor 101 is no longer shielded from light and its output becomes L (vehicle height "low"),
The output of the NAND gate NA ₄ is reversed to H, clearing the counter CO ₂ , and setting its output Q ₃ to L to close the exhaust valve 410 and stop lowering the vehicle height. On the other hand, 101
When the output of inverter IN ₂ changes from H to L,
When the counter CO ₁ counts 12 clock pulses, its output Q ₂ and Q ₃ become H at the same time, and the output of the NAND gate NA ₁ becomes H.
The output of inverter IN 4 is inverted to L, the count of CO ₁ is prohibited, and the output of NAND gate NA ₂ is inverted to H. At this time, the output of inverter IN ₄ is H, so the output of NAND gate NA ₅ is inverted to L, and this Since the output of the inverter IN ₂ becomes H after becoming L, the output of the AND gate AN ₆ maintains the H state, continues to clear the counter CO ₃ , and prohibits raising the vehicle height. Further, when the output of the photo sensor 101 is L (vehicle height "low") and the door is opened once and then closed, and the output of the NAND gate NA ₂ becomes L as described above, the output of the NAND gate NA ₅ becomes H, and the inverter IN ₂ Since the output of NAND gate NA 6 is H, the output of NAND gate NA ₆ is inverted to L and the clearing of counter CO ₃ is canceled. When the counter CO ₃ counts 8 pulses thereafter, the output Q ₃ becomes H, the output of the inverter IN ₄ is set to L to inhibit counting, and the output Q ₃ of CO ₃ is held at H. This energizes relay 440 via amplifier AMP ₂ , which drives motor 430 to drive compressor 420 and raise the vehicle height. The vehicle height increases and the state of the vehicle height detector 100 changes from the vehicle height "low" shown in FIG. 2c to the state shown in FIG. 2d,
The photo sensor 101 is shielded from light and its output is H.
(vehicle height "high") when reversed, Nand Gate NA ₆
The output of is inverted to H, clearing the counter CO ₃ ,
Set Q ₃ of CO ₃ to L to deenergize relay 440 and stop raising the vehicle height. On the other hand, when the output of 101 inverts from L to H, one input terminal of NAND gate NA ₄ becomes H, but before that, the other input terminal of NA ₄ inverts to L, so counter CO ₂ is cleared. condition, and lowering the vehicle height is prohibited. Furthermore, when the contact of the vehicle height changeover switch SW ₂ is connected to the "low" side, transistor Q ₁ is turned off and transistor Q ₂ is turned on, and current flows to the light emitting diode of the photo sensor 102 but not to the light emitting diode of the photo sensor 101. No current flows. Then, the light emitting diode of the photo sensor 101 does not emit light, the photo transistor 101 is turned off, and the output of the photo sensor 101 becomes H regardless of the vehicle height. Even when SW ₂ is set to "low", the operations of vehicle height adjustment control device 200 and vehicle height adjustment drive device 400 are the same as when set to "high". Vehicle height selector switch SW ₂ , transistor
The relationships among Q ₁ , Q ₂ , vehicle height, the outputs of the photo sensors 101 and 102, and the output of the AND gate AN ₁ are summarized in Table 1 below.

[Table] Next, the vehicle height adjustment operation when operating the vehicle height changeover switch _SW2 will be described with reference to the time chart in FIG. 3c. When vehicle height selector switch SW ₂ is set to ``high'' and the vehicle height detector is in the state shown in Figure 2d, when vehicle height selector switch SW <sub>2</sub> is set to ``low'' to lower the vehicle height, the monostable multi The input end of vibrator MM ₂ flips from L to H, and MM ₂ is triggered to have a negative (L) output on its output.
generates a pulse of This pulse is a NAND gate
Clear counter CO ₁ via NA ₇ . As a result, the output of NAND gate NA ₁ becomes H, and NA ₂
The output of NA ₃ and NA 5 becomes L and the outputs of NA 3 and NA ₅ are inverted to H. At this time, the vehicle height is set to 2nd level with the "lower" setting.
Since the condition is shown in Figure d, as shown in Table 1 above, 10
The output of AN 1 becomes H, the output of 102 becomes H, and the output of AN ₁ becomes H. Then, the output of the NAND gate _NA4 becomes L, and the clearing of the counter _CO2 is canceled. When the counter _CO2 has counted a predetermined value, its output terminal _Q3 is set to H and the vehicle height is lowered as described above. When the vehicle height is lowered and the vehicle height detector is in the state shown in FIG. 2c, and the output of the photo sensor 102 is reversed to L, the counter CO ₂ is cleared by NA ₄ and the lowering of the vehicle height is stopped. In addition, if the vehicle height selector switch SW ₂ is reset to "high" in this state,
The input of the monostable multivibrator MM ₁ flips from L to H, triggering MM ₁ to produce a negative (L) pulse at its output. This pulse clears counter CO ₁ via NAND gate NA ₇ .
As a result, the output of NAND gate NA ₁ becomes H, the output of NA ₂ becomes L, and the outputs of NA ₃ and NA ₅ are inverted to H. Also, when changing the vehicle height changeover switch SW ₂ , the vehicle height detector is
In the state shown in Figure c, the photo sensor 102 is not shielded from light, but when SW ₂ is switched, the transistor Q ₂ is turned off, the light emitting diode 102 goes out, the photo sensor 102 stops functioning, and the output is reversed to H. do. Then, the output of photo sensor 101 becomes L, the output of AN ₁ becomes L, and inverter IN ₂
With the output of NAND gate NA ₆ as L,
Clear counter CO ₃ . counter co ₃
When has completed a given count, its output terminal Q ₃
is set to H, and the compressor 420 is driven as described above to raise the vehicle height. When the output of the photo sensor 101 is reversed from L to H (see Figure 2d), NA ₆ clears the counter CO ₃ and Q ₃ of CO ₃ becomes L, stopping the vehicle height raising. FIGS. 4 and 5 show a modification of the above embodiment. The structure of the parts not shown in these drawings is the same as that shown in FIG. 3a. First, explanation will be given with reference to FIG. In this embodiment, the transistors Q ₁ and Q ₂ are omitted, and the photo sensors 101 and 102 are directly connected to each other by the changeover switch SW _2.
It turns on and off the current flowing through the light emitting diode. In addition _, when switching the changeover switch SW ₂ , _one contact opens and then the other closes (break-make contact). Orgate OR ₁ is provided instead. Furthermore, the outputs of the photo sensors 101 and 102 (collectors of the photo transistors) are connected to one resistor and an AND gate in the vehicle height adjustment control device 200 as a common connection.
AN ₁ has also been omitted. In this example,
When the vehicle height changeover switch SW ₂ is operated, the two inputs of the OR gate OR ₁ become H at the same time at the moment when the contact of SW ₂ changes, the output of OR ₁ becomes H, the output of the NAND gate NA ₇ becomes L, and the counter CO ₁ changes. Since clearing is canceled, the vehicle height is adjusted in the same way as in the previous embodiment. Next, a description will be given with reference to FIG. In this embodiment, the functions of the photo sensors 101 and 102 are turned on and off by a vehicle height changeover switch _SW2 provided on the ground side. Also in this embodiment, the circuit is constructed with a minimum number of parts by utilizing the fact that the vehicle height changeover switch _SW2 is a break-make contact. The output of the NAND gate NA ₈ is normally H, and becomes L only when the vehicle height changeover switch SW ₂ is switched, and the output of the NAND gate NA 8 is output to the vehicle height adjustment control device 2.
Give to 00. The same signals as in the previous embodiment (Table 1) are obtained from the photo sensors 101 and 102. FIG. 6a shows another configuration of the present invention, and FIG. 6b shows an example of its operation flow. Chapter 6a
This will be explained with reference to FIG. 6b. In this embodiment, the main part of the vehicle height adjustment control device 200 is composed of a microcomputer CPU, and a pressure switch 500 is connected to a flow path from the dryer 450 to the suspension device 401. The pressure switch 500 is of a type in which the contacts close when the pressure exceeds a predetermined value and open when the pressure decreases. The contact of the pressure switch 500 is connected to the input port P ₀ of the CPU,
Door switch SW ₁ and monostable multivibrator MM ₁ are connected to input port P ₁ , photo sensor 101,
102 is connected to the input port P ₂ , the amplifier AMP ₁ is connected to the output port P ₃ , the amplifier AMP ₂ is connected to the output port P ₄ , and the inverter IN ₅ is connected to the output port P ₅ . Note that MM ₁ uses an open collector output. The operation flow will be explained with reference to FIG. 6b. First, when the power is turned on, L is output to output ports P ₃ , P ₄ , and P ₅ as an initial setting, and at the same time, vehicle height adjustment is prohibited and the light emitting diode LED is turned off. Next, check input port _P0 to see if the pressure is normal. If the pressure is normal (high), check input port _P1 and read the status of door switch _SW1 . If the door is closed, the pressure switch 500 and door switch SW ₁ are checked repeatedly. Door opens input port P ₁
When the switch reverses to L, wait for some time (approximately 20ms) to remove the chattering of the door switch SW, then check input port _P1 again and _P1 becomes H.
Wait until it flips to (door closed). When the door is closed and port _P1 becomes H, wait for a while again to remove the chattering of the door switch SW, and then set the timer. This timer is used to wait until the vertical vibration of the vehicle body stops when a person gets on or off the vehicle. After this time has expired, the timer is set again to limit the upper limit of the vehicle height adjustment time. Then check port P ₂ and find that the vehicle height is "high"
If the vehicle height is “high” (P ₂ = H), H is output to the output port P ₃ and the exhaust valve 41 is
0 and lower the vehicle height. When port _P2 is reversed to L (vehicle height "low") or time-up occurs, L is output to port _P3 and vehicle height adjustment is stopped. If the vehicle height is determined to be "low", H is output to port _P4 , energizes the relay 440, drives the compressor 420, and raises the vehicle height. When port _P2 reverses to H (vehicle height "high") or time-up occurs, output L to port _P4 and stop adjusting the vehicle height. If the pressure switch 500 is activated and the check at the input port P ₀ determines that the pressure is "low" (abnormal), it outputs H to the ports P ₄ and P ₅ , turns on the light emitting diode LED, and turns on the relay 440. The compressor 420 is energized and the pressure is increased to raise the vehicle height. Set a timer to limit the time for this adjustment and
Wait for P ₀ to return to L (normal pressure). When the pressure returns to normal, output L to ports P ₄ and P ₅ ,
The light emitting diode LED is turned off, the relay 440 is deenergized, the drive of the compressor 420 is stopped, and the vehicle height adjustment is stopped. If the pressure does not return to normal and time-up occurs, output L to port _P4 , de-energize the relay 440, and turn off the compressor 420.
The drive is interrupted and the light emitting diode LED blinks to indicate that an abnormality has occurred. In addition, since the output of MM ₁ is also monitored at port P ₁ at the same time as the door opening/closing check, when vehicle height changeover switch SW ₂ is operated, the output of AN ₂ becomes H, triggering MM ₁ , and port P _1. When the predetermined time L has passed, the vehicle height is adjusted in the same way as in the case of the door switch _SW1 . As described above, according to the present invention, the target vehicle height can be switched with a simple configuration, and a circuit for selecting a signal is not required.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the mounting state of the vehicle height detector used in the embodiment of the present invention, Fig. 2a is a longitudinal sectional view of the vehicle height detector 100, Fig. 2b, Fig. 2c, and Fig. 2d.
Figure 2e and Figure 2e are cross-sectional views taken from the - line cross section in Figure 2a, showing different vehicle heights. FIG. 3a is a circuit diagram showing an embodiment of the present invention;
Figures 3b and 3c are time charts showing the operation of the apparatus of Figure 3a. Figures 4 and 5
The figure is a circuit diagram showing a modification of the embodiment of figure 3a. FIG. 6a is a circuit diagram showing another embodiment of the present invention, and FIG. 6b is a flowchart showing an example of its operation flow. 10: Vehicle body frame, 20: Link, 30: Differential gear, 40: Axle, 100: Vehicle height detector (vehicle height detector), 101, 102: Photo sensor (detection means), 104: Folding of light shielding plate 105 , 200: Vehicle height adjustment control device, 210: Clock generator, 401: Suspension device, 410: Exhaust valve (valve means), 420: Air compressor (pressure source), 430: Motor, 440: Relay,
SW ₁ : Door switch, SW ₂ : Vehicle height selection switch (selection means).

Claims (1)

[Scope of Claims] 1. A vehicle height detector having a plurality of detection means each having a light emitting element and a photoelectric conversion element, each of which has a different output state at different vehicle heights; - Turn off and selectively turn on the detection function of the detection means.
a selection means for turning off; a valve means and a pressure source for adjusting the fluid pressure of the suspension system; and an opening bias or pressure of the valve means so that the vehicle height reaches a target vehicle height in response to a signal from the selected detection means. A vehicle height adjustment device comprising: a vehicle height adjustment control device that performs power source drive; 2. The vehicle height adjustment control device is operated according to the binary signal output by the detection means, and when the signal is at a high level, it is inverted to a low level, and when the signal is at a low level, it is changed to a high level. The vehicle height adjustment device according to claim 1, wherein the vehicle height adjustment device is configured to bias the valve means open or drive the pressure source until the valve is reversed. 3. The vehicle height adjustment device according to claim 1 or 2, which is configured to give a vehicle height adjustment instruction to the vehicle height adjustment control device in conjunction with selection switching of the selection means.