JPS6214404B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a vehicle height adjustment device.

Conventionally, the relative position between the vehicle axle and the vehicle body, that is, the vehicle height, is detected using mechanical, electrostatic, magnetic, or optical detectors, and the detection signal from the detector is used to detect when the vehicle is stopped or when the vehicle is running. A vehicle height adjustment device that adjusts the vehicle height at the same time is known. In the adjustment, the vehicle height is defined in three states, for example, high, medium, and low, and the vehicle height judgment is correspondingly divided into three regions, high, medium, and low. Means for outputting a predetermined vehicle height adjustment signal when the detection signal obtained from the detector continuously vibrates within a high or low range within a certain period of time, or a high, medium, or low range. A method has been proposed in which the vehicle height signal corresponding to the vehicle height signal is integrated over a certain period of time, the average vehicle height is detected from the comparison result of the integrated value, and the vehicle height is adjusted based on this detection result. ing. By the way, with the former method, there is no problem with response when the vehicle height changes minutely, but on the other hand, when the vehicle height changes significantly due to an excessive impact while driving, the detection signal from the detector becomes multiple. If it varies between regions, an accurate response will not necessarily be obtained. On the other hand, with the latter method, the average vehicle height can be reliably determined even in cases of severe vibration, but on the other hand, a value of about 10 to 20 seconds is generally selected as the integration time, so it is usually 10 seconds. The vehicle height is adjusted based on the detection results based on the comparison results that are output once every ~20 seconds, and as a result, the vehicle height adjustment is excessive and the vehicle height is not set to the medium state, but instead is set to high or low. The state may be set again.

The present invention has been made in view of the above points,
The purpose is to provide a vehicle height adjustment device that can reliably detect the vehicle height when there is no vibration in the vehicle body even when the vehicle body is subject to strong vibrations, and can also prevent excessive adjustment of the vehicle height. It is in.

Next, a preferred specific example of the present invention will be explained based on the drawings.

In the suspension system 1 shown in FIG. 1, 2 is an outer cylinder of a shock absorber. The outer cylinder 2 has a mounting ring 3 at its lower end for connection to an axle, and a piston (not shown) and a piston rod 4 are slidably accommodated therein.

A cap 6 is hermetically fixed to the piston rod 4 by a mounting rod 5 or other means. The upper end of the mounting rod 5 is fixed to the vehicle body (not shown). The upper end of a cylinder 7 made of a non-magnetic material is hermetically fixed to the outer periphery of the cap 6. The cap 6 is a cylinder 7 that covers part of the outer periphery of the piston rod 4 and the outer cylinder 2.
is held. Incidentally, the cap 6 and the tube 7 may be formed integrally.

At the lower end of the cylinder 7, one end is sealed and fixed to the outer cylinder 2 with a fastener 8, and the other end is fixed to the outer cylinder 2 with a fastener 1.
0, thereby defining an air chamber 11 between the outer cylinder 2 and the cylinder 7. Air chamber 11
A pipe 12 is connected to the air chamber 1, and the pipe 12 is connected to the air chamber 1.
It is connected to an air supply side electromagnetic valve 13 and an exhaust side electromagnetic valve 14 that control the air pressure inside the air pump 1. Part or all of the weight of the vehicle is supported by the pressure of the compressed air introduced into the air chamber 11.

A magnet 15 is attached to the outer cylinder 2 along the axial direction of the outer cylinder 2.
is fixed. Two magnetic sensors 16 and 17 consisting of reed switches are fixed to the outer surface of the tube 7 facing the magnet 15. Sensors 16, 17
It is also possible to fix it to the inner surface of the cylinder 7. When the sensors 16 and 17 are fixed to the inner surface of the cylinder 7, the cylinder 7 does not necessarily have to be made of a non-magnetic material. When the vehicle height is at its lowest, the lower end 18 of the magnet 15
6 and 17, that is, the magnet 15 is the upper sensor 1.
6 only, and when the vehicle height is at its maximum, magnet 1
5 is moved below the position of the lower sensor 17, that is, both sensors 16 and 17 are inactivated,
Also, when the vehicle is at the standard height, the upper end 19 of the magnet 15
The sensor 1
6, 17 and magnet 15 are arranged, and the maximum stroke and amplitude of the shock absorber, the length of magnet 15, and the distance between sensors 16 and 17 are set.

On/off signals of the sensors 16 and 17 are supplied to a control device 20. Valve 13 is air compressor 21
The air compressor 21 generates compressed air by a driving source 22 such as an engine or a motor. The air compressor 21 has a pressure switch 23
is attached, and the switch 23 switches the drive source 2 when the generated compressed air pressure becomes higher than the specified value.
Automatically stops the operation in step 2. The control device 20 is supplied with a stop signal from a sensor 24 that detects whether the vehicle is stopped or running. The control device 20 has a determination circuit 25 that determines whether the vehicle height, that is, the position of the vehicle body relative to the axle, belongs to a high, standard, or low range based on signals from the sensors 16 and 17. The determination circuit 25 determines whether the vehicle height changes and the sensors 16, 17 and the magnet 15 are positioned so that both sensors 16, 17 output off signals (in the case of FIG. 4 1). outputting a region signal H as a determination result signal assuming that the height is in the high region;
Both sensors 1 are connected so that sensor 16 outputs an off signal and sensor 17 outputs an on signal.
6, 17 and the magnet 15 are located (Fig. 4 2)
), the vehicle height is assumed to be in the standard range, and the range signal M is output as a determination result signal, and both sensors 1
When both the sensors 16, 17 and the magnet 15 are positioned so that the ON signal is output from the sensors 6 and 17 (in the case of FIG. 4 3), the ON signal is output from the sensor 16, and the OFF signal is output from the sensor 17. When both the sensors 16, 17 and the magnet 15 are located so that the following is output (as in the case of FIG. 4), it is determined that the vehicle height is in the low region, and a region signal L is output as a determination result signal. These area signals H, M, and L are supplied to an integration circuit 26 as an integration circuit via a switching circuit 31 when a stop signal is not output from the stop sensor 24. The integration circuit 26 receives area signals H, M,
It has a digital integrator, for example a counter, corresponding to L, and each integrator has, within each time T,
When the corresponding area signals H, M, and L are input from the determination circuit 25, the pulses CL from the pulse generation circuit 27 are counted. Count values n _H , n _M , as integration result signals counted by each integrator of the integration circuit 26
n _L is output to the average position detection and area determination circuit 28 as a second determination circuit every time T elapses, while the count values of each integrator are cleared at the same time.

The detection/judgment circuit 28 detects the average vehicle height within time T from the count values n _H , n _M , n _L sent every time T elapses, and determines whether the vehicle height is again lower than this average vehicle height. Determine which region it belongs to: high, standard, or low. That is, the detection judgment circuit 28 detects the case where n _L > n _M , n _H = 0 and n _L > n _M > _{n H in} the count values n _H , n M , n _L (respectively in the case of FIG. ), assuming that the average vehicle height X is in the low region, output the region signal Lm, n _L < n _M , n _H = 0,
n _L < n _M > n _H , n _L > n _M < n _H , and n _L =0,
When nM> _nH (Fig. 6, , ,
), assuming that the average vehicle height X is in the standard region, the region signal Mm is output, and n _L < n _M < n
When _H and n _L =0 and n _H >n _M (respectively in the case of FIG. 6), it is assumed that the average vehicle height X is in the high region, and a region signal Hm is output. The vehicle height displacement pattern detection circuit 29 determines whether the area signal Hm or
When Lm is continuously supplied, for example, four or more times, the vehicle height adjustment signal A _H or A _L is output. Control circuit 30
When it receives the signal A _L , it outputs a valve open signal to the valve 13, and when it receives the signal A _H , it outputs a valve open signal to the valve 14, but when it does not receive either the signals A _L or A _H , it outputs a valve open signal to the valve 13. , outputs a valve close signal to valve 13 and valve 14. When the switching circuit 31 receives a stop signal from the stop sensor 24, that is, when the vehicle is stopped, the switching circuit 31 directly supplies the area signals H and L, which are the outputs of the determination circuit 25, to the control circuit 30; When the stop signal is not received from the sensor 25, that is, when the vehicle is running, the determination circuit 25
The area signals H, M, and L are supplied to the integration circuit 26. Therefore, when the stop signal is output from the stop sensor 25, the control circuit 30 outputs the valve open signal A according to the area signals H and L from the switching circuit 31.
The opening and closing of valves 13 and 14 is controlled in the same manner as in _H and A _L. Pattern detection circuit 29, control circuit 30, suspension system 1, valves 13, 14, compressor 21
This constitutes an adjustment circuit that adjusts the vehicle height. The control circuit 30 turns on and off a vehicle height display device, such as a lamp 40, to display whether the vehicle height is in a high or low range, or whether the vehicle height is in a standard range. You can also do this.

The operation of the vehicle height adjustment device configured as described above will be explained. P indicates the locus of change in vehicle height when the vehicle height changes moment by moment due to unevenness of the road surface while the vehicle is currently driving. When the vehicle height changes as shown in the trajectory P, both sensors 1
On/off signals are output from 6 and 17 and input to the determination circuit 25. The determination circuit 25 outputs area signals H, M, and L according to the input on/off signals, respectively. The area signals H, M, and L are provided by the switching circuit 31.
is supplied to the integration circuit 26 via the integration circuit 26.
detects the duration of the area signals H, M, and L within a certain time T as the number of clock pulses CL.
For example, as shown in FIG.
Within, the region signal H does not occur, the region signal M occurs during the period t _M , and the region signal L occurs during the period t _L1 +
t _L2 , each of the integrators of the integrator circuit 26 has a count value n _H =0, n _M =1, and n _L =9.
These count values n _H , n _M , n _L are supplied to the detection determination circuit 28 . The detection/judgment circuit 28 detects the average vehicle height within a certain time T based on the received count values n _H , n _M , n _L , and determines in which region this average vehicle height is located. do. For example, the first period T
Since n _L > n _M and n _H = 0 (this is the case shown in FIG. 6), the detection judgment circuit 28 outputs the area signal Lm to the pattern detection circuit 29 as being lower than the standard vehicle height. . Next, the pattern detection circuit 29 checks the continuity of the area signals Hm, Mm, and Lm received every period T in this manner. When the area signal Hm or Lm is continuously input for four times longer than the period T, the pattern detection circuit 29 outputs the vehicle height adjustment signal A _H or A _L to the control circuit 30. That is, when the area signal Hm is inputted four times or more consecutively in units of cumulative time T, the vehicle height adjustment signal A _H
On the other hand, when the area signal Lm is input four or more times in succession, the pattern detection circuit 29 outputs the vehicle height adjustment signal A _L to the control circuit 30. Note that if the area signal Hm or Lm is input continuously for more than four times the period T, and then the area signal Mm is input even once, the pattern detection circuit 29 outputs the vehicle height adjustment signal A _L or A _H. Stop and turn area signal Hm or Lm again
The occurrence and persistence of Therefore, the pattern detection circuit 29 now detects four consecutive signals from the detection judgment circuit 28.
When the pattern detection circuit 29 receives the area signal Lm more than once, the pattern detection circuit 29 outputs the vehicle height adjustment signal A _L. When the control circuit 30 receives the vehicle height adjustment signal A _L , the control circuit 30 closes the valve 1
Outputs a valve open signal that excites 3. When the valve 13 is energized, compressed air from the air compressor 21 is supplied to the air chamber 11 of the suspension system 1 through the pipe 12, the cylinder 7 and the piston rod 4 are raised, and the vehicle body is raised. After this increase, in the count values from the integrating circuit 26, n _L < n _M , n _H = 0 (in the case of Fig. 6), n _L < n _M > n _H (in the case of Fig. 6), n _L >
n _M < n _H (in the case of Figure 6), n _L = 0, n _M > n _H
(In the case of FIG. 6), the detection/judgment circuit 28 determines that the average vehicle height is in the standard area and outputs the area signal Mm to the pattern detection circuit 29. The pattern detection circuit 29 receives the area signal Mm
Upon reception of the vehicle height adjustment signal A L, the transmission of the vehicle height adjustment signal A _L is stopped. When the control circuit 30 stops receiving the vehicle height adjustment signal A _L , it stops sending out the valve opening signal in order to eliminate the excitation of the valve 13, and therefore stops the compression from the air compressor 21 to the air chamber 11. The air supply is stopped and the vehicle body is set to approximately the standard vehicle height. Integration circuit 2 below
In the count values n _H , n _M , n _L from 6, n _L <n
_M < n _H (in the case of Figure 6), and n _L =0 n _H >
n _M (in the case of FIG. 6) is also the same, and the detection judgment circuit 28 continuously receives the area signal for more than four times the period T.
When Hm is input to the pattern detection circuit 29, the pattern detection circuit 29 outputs the vehicle height adjustment signal A _H to the control circuit 30, and the control circuit 30 outputs the vehicle height adjustment signal A
When it receives _H , it outputs a valve opening signal that excites the valve 14. When the valve 14 is excited, the compressed air in the air chamber 11 is discharged to the outside via the pipe 12 and the valve 14, and at the same time, the average vehicle height is successively lowered. Then, when the area signal Mm is input from the detection determination circuit 28 to the pattern detection circuit 29, the pattern detection circuit 29 controls the vehicle height adjustment signal A _H to the control circuit 3.
0 is stopped and the control circuit 30
4 is de-energized, the discharge of compressed air from the air chamber 11 is stopped, and the vehicle body is set at approximately the standard vehicle height. Note that when the vehicle is stopped and a stop signal is supplied from the stop sensor 24 to the switching circuit 31, the area signals H and L of the determination circuit 25 are directly supplied to the control circuit 30, and the control circuit 30 receives the area signal H. In this case, the valve 14 is excited in the same manner as when receiving the vehicle height adjustment signal A _H , and the valve 13 is excited in the same way as in receiving the vehicle height adjustment signal A _L when receiving the region signal L. Note that the integration period T as the integration period is preferably about 2 to 5 seconds. Furthermore, although the integration of the area signals H, M, and L is performed digitally using the integration circuit 26, the present invention is not limited to this, and the area signals H, M, and L are time-integrated in an analog manner. Good too. In addition, the average vehicle height was determined by continuing the area signal Hm or Lm for more than four times the period T, but the multiple is The vehicle height adjustment operation may be set optimally, and the vehicle height adjustment operation is stopped immediately upon generation of the area signal Mm. In this case, the vehicle height adjustment operation may be stopped.

As described above, according to the present invention, the vehicle height adjustment operation is started by detecting a vehicle height that can be considered to be approximately the vehicle height when the vehicle is stopped, and the vehicle height adjustment operation is stopped by temporarily detecting the standard vehicle height. Therefore, while not responding to temporary changes in vehicle height, it is possible to prevent the adjustment operation from going too far. Further, since the integral method is used, the average vehicle height can be detected no matter what the vehicle height change, and the almost perfect vehicle height adjustment can be performed. In addition, by using an integration circuit as an integration circuit, digital processing is possible, configuration using a microprocessor is possible, and an inexpensive device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional explanatory diagram of a suspension device according to one embodiment of the present invention, FIG. 2 is a block diagram of one embodiment of the present invention,
Fig. 3 is a detailed block diagram of the control device shown in Fig. 2, Fig. 4 is an explanatory diagram showing the relationship between the positions and areas of the sensors and magnets, and Fig. 5 is the operation time of the specific example shown in Fig. 2. FIG. 6 is an explanatory diagram of the operation of the fluctuation pattern detection circuit shown in FIG. 3. 1... Suspension device, 13, 14... Solenoid valve, 15
... Magnet, 16, 17 ... Sensor, 20 ... Control device, 21 ... Air compressor, 24 ... Stop sensor, 25 ... Judgment circuit.

Claims (1)

[Claims] 1. A detector that detects the position of the vehicle body relative to the axle, and a signal from the detector that determines which vehicle height region among a plurality of vehicle height regions the vehicle body belongs to regarding the position of the vehicle body relative to the axle. a first determination circuit that integrates each determination result signal from the first determination circuit for a certain period of time; and an integration circuit that integrates each determination result signal from the first determination circuit for a certain period of time; A second determination circuit determines which vehicle height region the vehicle belongs to, and a determination result signal indicating that vehicle height adjustment is required is continuously output with respect to each determination result signal from the second determination circuit. A vehicle height adjustment device consisting of an adjustment circuit that adjusts the position of the vehicle body relative to the axle. 2. The vehicle height adjustment device according to claim 1, wherein the integrating circuit is an integrating circuit that counts pulses supplied while the determination result signal from the first determining circuit is generated. 3. Claims in which the second determination circuit is configured to determine which of the vehicle height regions the position of the vehicle body relative to the axle belongs to by comparing the counts as each integral result signal from the integration circuit. The vehicle height adjustment device according to item 2. 4. The vehicle height adjustment device according to any one of claims 1 to 3, wherein the integration time is 2 to 5 seconds. 5. Claim No. 5, wherein the adjustment circuit performs the adjustment operation when the determination result signal indicating that vehicle height adjustment is required is continuously outputted from the second determination circuit four or more times in units of integral time. The vehicle height adjustment device according to any one of items 1 to 4.