JPH0618802Y2 - Vehicle signal converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a vehicle signal conversion device effective for obtaining a polarity signal of relative displacement between a vehicle wheel and a vehicle body.

[Prior Art] Conventionally, there has been a technique for improving the ride comfort and the grounding property of wheels by adjusting the transmission force transmitted from the road surface of the vehicle to the vehicle body via the shock absorber by switching the damping force of the shock absorber. Are known. As such, for example, the direction determination means determines the direction of the transmission force transmitted from the road surface to the vehicle body through the suspension,
A "shock absorber control device" (Japanese Unexamined Patent Publication No. 60-248419) for controlling the damping force variable shock absorber to a low damping force when the determination result is the vibration direction and to a high damping force otherwise. Is proposed.

[Problems to be Solved by the Invention] By the way, in order to perform the above control, it is necessary to determine the direction of the transmission force transmitted from the road surface to the vehicle body. The determination of the direction of this transmission force is determined by the relative displacement between the unsprung member supporting the wheel and the sprung member connected to the vehicle body,
It was performed based on the positive / negative of the difference with the preset neutral displacement. The neutral displacement between the unsprung member and the unsprung member changes to various values depending on factors such as the number of occupants of the vehicle and the weight of the vehicle, so the neutral displacement that changes in this way and the unevenness of the road surface during vehicle traveling. In order to perform the damping force switching control of the shock absorber by comparing it with the relative displacement that changes corresponding to the above, it was necessary to store the neutral displacement.

However, since the neutral displacement is stored in a storage element such as an analog memory or a digital memory, the circuit configuration of the device becomes complicated.

In addition, for example, when the neutral displacement is stored by an analog memory, a predetermined required performance cannot be exhibited due to the occurrence of gain fluctuation and drift, and moreover, there is a problem that a battery backup is required in case of power shutdown. there were.

Further, it is necessary to adjust the zero point of the detector that detects the relative displacement between the sprung member and the unsprung member to the 0 position of the relative displacement or the maximum displacement position, which deteriorates workability and increases the number of work steps. There was also the problem of inviting.

Further, for example, in a configuration in which the neutral displacement is stored by a digital memory, a battery backup for supplying power for storage retention and a control circuit for controlling the digital memory are required, which causes a problem that the circuit configuration becomes complicated.

An object of the present invention is to provide a vehicular signal conversion device having a simple configuration and capable of suitably generating a polarity signal of relative displacement between a vehicle wheel and a vehicle body.

Configuration of the Invention [Means for Solving the Problems] The present invention, which has been made to solve the above problems, detects relative displacement between a vehicle wheel and a vehicle body, and at least,
Based on the relative displacement detection means that outputs a direction signal corresponding to the displacement direction of the relative displacement and the direction signal output by the relative displacement detection means, when the displacement direction of the relative displacement is the predetermined direction, the count value is increased. On the other hand, when the displacement direction of the relative displacement is the direction opposite to the predetermined direction, the calculation means for decreasing the count value, and the count value of the calculation means when the vehicle attitude of the vehicle is in a steady state. A setting means for setting a predetermined value; and a comparing means for outputting a comparison signal which is inverted depending on a comparison result of whether or not the count value of the calculating means exceeds a predetermined reference value. The gist is a characteristic signal conversion device for a vehicle.

The relative displacement detecting means detects a relative displacement between a vehicle wheel and a vehicle body and outputs at least a direction signal corresponding to the displacement direction of the relative displacement. For example, it is interposed between a wheel and a vehicle body, detects a relative displacement between the wheel and the vehicle body as a rotation angle, and outputs two types of signals having a predetermined phase difference in an order according to the displacement direction of the relative displacement. This can be realized by a rotary encoder and a phase discriminator that outputs, as a direction signal, a signal corresponding to the advance or delay of the phase of two types of output signals of the rotary encoder.

Based on the direction signal output from the relative displacement detection means, the computing means increments the count value when the displacement direction of the relative displacement is the predetermined direction, while the displacement direction of the relative displacement is opposite to the predetermined direction. In the case of, the count value is decreased. For example, various counts such as an up-down counter that down-counts the count value when the relative displacement is decreasing, and up-counts the count value when the relative displacement is increasing. It can be composed of a circuit.

The setting means sets the count value of the calculating means to a predetermined value when the vehicle attitude of the vehicle is in a steady state.
Here, the vehicle attitude being in a steady state means, for example, a state in which the vehicle is not running or stopped on an uneven or sloped road surface, a state not affected by a disturbance such as a side wind, or a sudden start + a sudden braking. For example, the vehicle is in a state in which the vehicle is not tilted, and the vehicle is in a substantially horizontal posture. Therefore, for example, a detector such as a vehicle speed sensor, a brake switch, an inclination sensor, and the like, and a reset circuit that resets the count value to 0 according to the detection signal of the detector can be used. Further, for example, a reset switch and a reset circuit that are operated by the driver after confirming that the driver is in the steady state of the vehicle attitude may be used.

The comparison means outputs a comparison signal which is inverted according to the comparison result of whether the count value of the calculation means exceeds a predetermined reference value. For example, the count value of the computing means is used as one input, and the reference value set by a digital switch or the like is used as the other input to compare the two. When the count value is larger than the reference value, a high level signal is given, and the count value is given. When is smaller than the reference value, it can be realized by a comparator that outputs a low level signal.

[Operation] In the vehicle signal conversion device of the present invention, the vehicle attitude of the vehicle is in a steady state based on the direction signal output from the relative displacement detection means and corresponding to the displacement direction of the relative displacement between the vehicle wheel and the vehicle body. The computing means increases the count value set to the predetermined value by the setting means when the displacement direction of the relative displacement is in the predetermined direction, while the displacement direction of the relative displacement is in the direction opposite to the predetermined direction. In this case, the comparison means outputs a comparison signal which is decreased when the count value exceeds the predetermined reference value and which is inverted according to the comparison result of whether the count value exceeds a predetermined reference value.

That is, the count value set to a predetermined value when the vehicle is in a steady state is increased or decreased according to a direction signal corresponding to the displacement direction of the relative displacement between the wheel and the vehicle body, and the count value and the reference value are calculated. A comparison signal that is inverted according to the magnitude comparison result is output.

Therefore, the vehicular signal conversion device of the present invention has a simple device configuration and functions to input the relative displacement between the wheel and the vehicle body and output the polarity signal thereof.

The technical problems of the present invention are solved by the action of each component of the present invention as described above.

[Embodiment] Next, a preferred embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a device configuration of a shock absorber control device having a vehicle signal conversion circuit according to an embodiment of the present invention.

As shown in the figure, the shock absorber control device 1 is
The coil spring 4 interposed between the wheel 2 and the body 3 and the control rod 5a and the valve 5b of the shock absorber 5 provided side by side are rotated to reduce the damping force to a high damping force (HARD) and a low damping force (SOFT). ), A motor 6, a pulley 7 having a sufficiently long circumference that does not make one rotation with respect to the total variation range of the relative displacement between the wheel 2 and the body 3, and the pulley 7 changes the relative displacement. The wheel 2 is set so as not to make one rotation even if the range is over.
A rotary encoder 8 for detecting relative displacement between the body 3 and the body 3, a relative speed polarity signal generation circuit 9 for generating a relative speed polarity signal from a displacement signal output from the rotary encoder 8, and a signal from the relative speed polarity signal generation circuit 9. Relative displacement polarity signal generation circuit 1 for generating a relative displacement polarity signal by
0, inputting the relative velocity polarity signal and the relative displacement polarity signal, the damping force of the shock absorber 5 is set to high + low 2
It is composed of a damping force switching signal generation circuit 11 for outputting a damping force switching signal for switching between stages and a drive circuit 12 for driving the motor 6 in response to the damping force switching signal.

The relative velocity polarity signal generation circuit 9 is composed of a phase discriminator 13 and an RS flip-flop 14.

The relative displacement polarity signal generation circuit 10 is composed of up / down counters 15, 16, 17, 4-bit comparators 18, 19, 20 and digital switches 21, 22, 23 for setting a predetermined set value.
The comparators 18, 19 and 20 receive the count values of the up / down counters 15, 16 and 17 as one input and the set values of the digital switches 21, 22 and 23 as the other input, and compare the two. Further, the up / down counters 15, 16 and 17 are provided with a reset circuit 24.
It is reset by the reset signal from. The reset circuit 24 includes a NAND circuit 24a and an inverter 24b, and the NAND circuit 24a includes a vehicle speed sensor 25.
And the signal from the brake switch 26 is input.
Here, the vehicle speed sensor 25 outputs a high level (value 1) signal when the vehicle speed is 0, and the brake switch 26 outputs a high level (value 1) signal when not braking. In the present embodiment, since the rotary encoder 8 outputs 600 pulse signals per rotation, the value 300 is set to the digital switches 21, 22, and 23.

Further, the damping force switching signal generation circuit 11 includes an anti-coincidence circuit 27, a NOT circuit 28, an RS flip-flop 29,
30 and Schmitt trigger circuits 31 and 32.

As shown in FIG. 2, the relative speed polarity signal generating circuit 9 includes capacitors 41, 42, NOT circuits 43, 44, N.
Phase discriminator 13 composed of AND circuits 45 and 46, NAN
It is composed of an RS flip-flop 14 including D circuits 47 and 48 and a NOT circuit 49.

Next, the operation will be described with reference to the circuit diagram of FIG. 2 and the timing charts of FIGS. 3 and 4. The third
Waveforms at respective points shown in FIGS. 4 and 5 are observed at positions indicated by the same reference numerals in the circuit diagram of FIG. When the relative displacement decreases, the rotary encoder 8
1/4 as the r1 and r2 waveforms shown in the figure
Two pulse trains having a wavelength phase difference (interval between time τ1 and time τ2) are output. The r1 point waveform is at time τ3.
At this time, it changes to a low level, but at this time, a pulse train like an s-point waveform is obtained by the action of the capacitor 41 and the NOT circuit 43. The s-point waveform and the r2-point waveform are input to the NAND circuit 45, and as its output, a pulse train like the a-point waveform is obtained as one output of the phase discriminator 13. As shown in FIG. 4, when the relative displacement decreases, one waveform of the point a, which is one output of the phase discriminator 13, becomes a pulse train, and the other output of the phase discriminator 13 e.
The point waveform is maintained at high level. On the other hand, when the relative displacement increases, the point a waveform is maintained at a high level, and the point e waveform becomes a pulse train. The NAND circuit 4 in which the point a waveform and the point e waveform form the RS flip-flop 14
It is input to 7,48. Therefore, the time τ11 of the point a waveform
The rsf point waveform which is the output of the RS flip-flop 14 is set to the high level in response to the change to the low level at. On the other hand, the rsf point waveform is reset to the low level according to the change of the point e waveform to the low level at time τ12. Thereafter, similarly, the rsf point waveform changes at time τ13, τ14, τ1 in accordance with changes in the point a waveform and the point e waveform.
At 5, the set and reset are repeated. The rsf point waveform output from the RS flip-flop 14 is NO
It is inverted by the action of the T circuit 49 and is output as a point b waveform which is a relative velocity polarity signal.

Next, as shown in FIG. 5, the damping force switching signal generating circuit 11 causes the polarity of the relative displacement between the wheel 2 and the body 3 (indicated by a solid line in the figure) and the relative speed (indicated by a broken line in the figure). When the polarity of the shock absorber 5 is in the same phase (same sign), {time t2 to t3, time t4 to t5}, the damping force of the shock absorber 5 is low damping force (SOFT), while the opposite phase (different sign). At time {time t1 to t2, time t3 to t4, time t5 to t6}, the drive circuit 12 outputs a control signal for switching to a high damping force (HARD).
To output to.

Next, the first operation of the shock absorber control device 1 will be described.
It will be described with reference to FIGS. The waveform of each point shown in the timing chart of FIG. 6 is observed at the positions shown by the same reference numerals in FIG. By the reset signal from the reset circuit 24 corresponding to the signals from the vehicle speed sensor 25 and the brake switch 26, the up / down counters 15, 16, 17 are set to the value 00 at time T1.
It is reset to 0, and the relative displacement at the same time T1 becomes the reference displacement. After the same time T1, when the relative displacement (shown by the solid line in FIG. 6) decreases with the movement of the vehicle from the reference displacement,
The waveform at point a which is one output signal of the phase discriminator 13 is
The pulse signal output from the rotary encoder 8 and the output signal b of the RS flip-flop 14
The waveform of the point {relative velocity polarity signal} becomes low level (value 0). At this time, the up / down counters 15, 16, 1
Since the counting state of 7 becomes the subtraction state (DOWN),
As shown in the figure, the count value is 99 according to the number of pulses (waveform at point a) output from the rotary encoder 8.
It decreases to 9,998,997. Here, the comparators 18, 19 and 20 are connected to the up / down counter 15,
16 and 17 count value (input A) and preset value 300 of the digital switches 21, 22 and 23
(Input B) is compared, and since input A is larger than input B, the waveform {relative displacement polarity signal} at point c, which is the comparison signal, becomes high level (value 1). Therefore, the output of the anti-coincidence circuit 27 to which the relative velocity polarity signal {waveform at point b (value 0 here)} and the relative displacement polarity signal {waveform at point c (value 1 here)} are input Control signal (waveform at point d)
Becomes high level (value 1). Therefore, the shock absorber damping force is switched to the high damping force (HARD).

Next, at time T2, as shown in FIG. 6, when the direction of the relative displacement changes and begins to increase, in this case, the waveform at the point a which is the output signal of the phase discriminator 13 is at a high level (value The waveform of the point e, which is the other output signal of the phase discriminator 13 which is held in 1), becomes the pulse signal output from the rotary encoder 8 and also the point b of the output signal of the RS flip-flop 14. The waveform {relative velocity polarity signal} becomes high level (value 1). At this time, the counting state of the up / down counters 15, 16 and 17 becomes the adding state (UP), so that the counting value is the number of pulses output from the rotary encoder 8 (waveform at point e), as shown in FIG. ), It increases to 993,992,993. Here, the comparators 18, 19, 20 compare the count value of the up / down counters 15, 16, 17 (input A) with the preset value 300 (input B) of the digital switches 21, 22, 23. Compare and input A
Is still larger than input B, the waveform {relative displacement polarity signal} at point c, which is the comparison signal, is maintained at a high level (value 1). Therefore, the output of the anti-coincidence circuit 27 which receives the relative velocity polarity signal {waveform at point b (here, value 1)} and the relative displacement polarity signal {waveform at point c (here, value 1)} Control signal (waveform at point d) to be turned on is low level (value 0)
become. Therefore, the shock absorber damping force is switched to the low damping force (SOFT).

Eventually, at time T3, the count values of the up / down counters 15, 16 and 17 in the addition state (UP) are the number of pulses output from the rotary encoder 8 (waveform at point e).
In accordance with the increase of 999,000,001,002. Here, the comparators 18, 19, 20 compare the count value of the up / down counters 15, 16, 17 (input A) with the preset value 300 (input B) of the digital switches 21, 22, 23. Compare and input A
Becomes smaller than the input B, the waveform {relative displacement polarity signal} at the point c, which is the comparison signal, changes to the low level (value 0). Therefore, the output of the anti-coincidence circuit 27 which receives the relative velocity polarity signal {waveform at point b (here, value 1)} and the relative displacement polarity signal {waveform at point c (here, value 0)} The control signal (waveform at point d) to be turned on is at high level (value 1)
become. Therefore, the shock absorber damping force is switched to the high damping force (HARD). After that, the relative velocity polarity signal (waveform at point b) and the relative displacement polarity signal (waveform at point c)
When and are in phase, low damping force (SOFT) {time T4 to T
5, time T6 to T7, time T8 to T9}, high damping force (HARD) in the reverse phase {time T3 to T4, time T5 to T
6, the control for switching to each of times T7 to T8} is continued.

In the present embodiment, the rotary encoder 8 and the phase discriminator 13 serve as relative displacement detecting means, the up / down counters 15, 16, 17 serve as computing means, the reset circuit 24 serves as setting means, and the comparators 18, 19, 20 serve as comparators. Each corresponds to a comparison means.

As described above, according to this embodiment, the up / down counters 15, 16, 17 and the comparators 18, 19, 2 are provided.
0, a digital switch 21, 22, 23, and a reset circuit 24, with a simple circuit configuration, it is possible to set the neutral position of the relative displacement between the wheel 2 and the body 3 that frequently changes according to the number of passengers and the weight of the vehicle. , The direction of relative displacement between the wheel 2 and the body 3 is determined by the rotary encoder 8 and the phase discriminator 1.
If detected by 3, the polarity signal can be accurately generated.

Further, by only disposing one rotary encoder 8 for detecting the relative displacement between the wheel 2 and the body 3 for each wheel, the relative displacement of the relative displacement can be obtained without providing a dedicated acceleration sensor for detecting sprung acceleration or the like. Since the polarity signal is obtained, the mountability on the chassis of the device is improved.

Furthermore, an up / down counter 1 that stores the neutral position
5, 16 and 17 and the reset circuit 24 are not adversely affected by gain change and drift, so that the required performance can be sufficiently exerted, and battery backup for retaining the memory is unnecessary, so that electrical noise from the outside is not necessary. When used under adverse conditions such as acceleration applied when the vehicle is running and temperature changes over a wide range, reliability + durability can be improved, and a large mounting space becomes unnecessary when mounted on the vehicle.
Its mountability is also improved.

Further, when the relative displacement polarity signal generating circuit 10 is mounted on the vehicle, adjustment such as adjusting the zero point of the rotary encoder 8 according to the displacement 0 position of the relative displacement or the maximum displacement position becomes unnecessary. The mounting work on the board becomes extremely easy, and the man-hours and manufacturing cost can be reduced.

Furthermore, since a relative displacement polarity signal and a relative velocity polarity signal between the wheel and the vehicle body are obtained, a shock absorber damping force switching control for suppressing vehicle body vibration is performed based on the so-called skyhook principle by using the bipolar signals. Can be suitably executed. That is, if the relative displacement polarity signal and the relative velocity polarity signal are in phase, they are switched to the low damping force side, and if they are in reverse phase, they are switched to the high damping force side.

It should be noted that in this embodiment, the vehicle speed sensor 2 is provided in the reset circuit 24.
5 and the brake switch 26 are connected. However, for example, in addition to these sensors and switches, an inclination sensor that detects the inclination of the vehicle may be connected. In such a configuration, for example, the roll-direction tilt sensor outputs a high level (value 1) signal when the roll angle is 0 [°], and the pitch-direction tilt sensor when the pitch angle is 0 [°]. Is set to output a high level (value 1) signal.

In this embodiment, the relative speed polarity signal generation circuit 9 outputs the relative speed polarity signal. But,
For example, when the relative displacement shown by the solid line in FIG. 6 is differentiated by the differentiating circuit, the relative velocity shown by the broken line in the figure is obtained. Therefore, when the sign of the relative speed obtained by the differentiating circuit is determined to generate the relative speed polarity signal, the same effect as that of the above-described embodiment can be obtained with a simple circuit structure.

Further, although the reset circuit 24 connected to the vehicle speed sensor 25 and the brake switch 26 is used in the present embodiment, for example, instead of each of the above-mentioned sensors and switches, any vehicle from the minimum loading state to the maximum loading state of the vehicle can be used. In this state, a reset switch capable of outputting a reset signal by a driver's operation when the vehicle is determined to be horizontal based on various conditions may be connected to the reset circuit 24.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and it is needless to say that the present invention can be implemented in various modes without departing from the scope of the present invention. .

Effect of the Invention As described in detail above, in the vehicle signal conversion circuit of the present invention, the count value set to a predetermined value when the vehicle is in a steady state corresponds to the displacement direction of the relative displacement between the wheel and the vehicle body. It is configured to perform an increase / decrease calculation according to the direction signal and output a comparison signal that is inverted according to the magnitude comparison result of the count value and the reference value. Therefore, the neutral position of the relative displacement of the vehicle that frequently changes according to the number of passengers and the loaded weight can be stored with a simple device configuration, and from the displacement direction of the relative displacement between the wheel and the vehicle body,
It has an excellent effect that the polarity signal can be obtained accurately.

Further, by arranging one detector for detecting the relative displacement between the wheel and the vehicle body for each wheel, the polarity of the relative displacement can be obtained without providing another detector for detecting sprung acceleration and the like. The signal is obtained.

This shows a particularly remarkable effect when mounted on a chassis of a vehicle that requires lightweight and small size and high vibration resistance.

Furthermore, since it is not adversely affected by the gain change and drift of the device and the power supply for storage is not necessary, it is not possible to have an external electrical noise, a large acceleration acting in three directions, a temperature change over a wide range, and the like. In addition to improving the reliability and durability of the vehicle signal conversion device used in an environment, a wide mounting space is not required when the vehicle is mounted, and its mounting property is also improved.

Further, when the device is mounted on each vehicle, it is not necessary to perform complicated adjustments such as adjusting the zero point of the relative displacement detector according to the relative displacement, so that workability at the time of mounting on the vehicle is improved and work is performed. The man-hours can be reduced and the manufacturing cost can be reduced.

Further, since the comparison signal which is the polarity signal of the relative displacement between the wheel and the vehicle body is obtained, it can be effectively used for the damping force switching control of the shock absorber that suppresses the vehicle body vibration based on the so-called skyhook principle.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing the relative speed polarity signal generating circuit, FIG.
4 is a timing chart showing the operation of the relative speed polarity signal generating circuit, FIG. 5 is a timing chart showing the operation of the control circuit, and FIG. 6 is a timing chart showing the operation of the shock absorber control device. Is. 8 ... Rotary encoder 9 ... Relative velocity polarity signal generation circuit 10 ... Relative displacement polarity signal generation circuit 24 ... Reset circuit

Claims (1)

[Scope of utility model registration request] 1. A relative displacement between a vehicle wheel and a vehicle body is detected,
At least based on the relative displacement detection means that outputs a direction signal corresponding to the displacement direction of the relative displacement, and the displacement direction of the relative displacement based on the direction signal output by the relative displacement detection means, the count value On the other hand, when the displacement direction of the relative displacement is opposite to the predetermined direction, the calculation means for decreasing the count value and the calculation means for calculating the calculation means when the vehicle attitude of the vehicle is in a steady state. A setting means for setting a numerical value to a predetermined value; and a comparing means for outputting a comparison signal which is inverted according to a comparison result of whether or not the count value of the calculating means exceeds a predetermined reference value. A vehicle signal conversion device characterized by the above.