JPS5959511A - Vehicular height adjusting device - Google Patents

Abstract

PURPOSE:To improve safety in running, by automatically adjusting a vehicular height set value to a safety limit upon start of a vehicle in the case that a vehicular height value in a halt of the vehicle exceeds the safety limit such that the value influences a safety running. CONSTITUTION:In operation of a vehicular height setting device 22 allowing a vehicular height to be arbitrarily set to such a value as to exceed a safety limit permissible in running, a switching means 32 is operated according to a signal from a vehicular speed sensor 24, and a signal from the vehicular height setting device 22 is directly fed to a control device 39 in a halt of a vehicle, while it is fed through a first and a second comparing means 35 and 36 to the control device 39 during running. Each comparing means 35 and 36 serves to compare an output signal from the setting device 22 with a high level and a low level vehicular height reference signal permissible in running from signal generators 33 and 34. when the veticular height setting signal exceeds the highest limit of the veticular height, the vehicular height setting signal is compensated to a high and a low level vehicular height value by compensating means 37 and 38, and then is fed to the control device 39.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle height adjustment device for a vehicle equipped with an air spring large suspension device.

The air spring bodywork @C allows the vehicle height to be freely adjusted by adjusting the amount of air in the air spring. Therefore, while the Tp vehicle is stopped, the height of the vehicle may be lowered for passengers to get on and off, or in the case of a truck, the height of the opposite side should be made to match the height of the warehouse platform, etc., and the height of the forklift truck may be lowered to allow the driver to get on and off the vehicle. Loading and unloading can be done quickly.

However, moving the vehicle lower than the minimum vehicle height or higher than the maximum vehicle height for normal driving not only impairs its characteristics as an air spring, but also is at risk of being overthrown.

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problem, and to provide a vehicle in which the safety limit height is automatically adjusted when the vehicle starts from a state where the vehicle height exceeds the vehicle height limit set for driving. Our goal is to provide highly adjustable equipment.

For this reason, the present invention provides a suspension system that controls the vehicle height by adjusting the amount of air in an air spring disposed between the vehicle body and the axle using a vehicle height adjustment valve, and a vehicle height sensor disposed on the air spring. 6) A vehicle height setting device that generates a slope value for maintaining the vehicle height within a predetermined range; and a vehicle height setting device that controls the signal of the vehicle height setting device when the vehicle is stopped based on the signal of the vehicle speed sensor. It is sent directly to the control device, and the first one is sent while driving. Second
switching means for sending a signal to a comparison means for a first vehicle height (
ΔQ11 generator, a second medium/high signal generator that generates a signal corresponding to the low level vehicle height to be punched while traveling, and a second medium/high signal generator (No. 2 and the switching means of the first medium/high signal generator) the first comparing means for comparing the signal J of the vehicle height setting device applied via the shuttle; and the signal of the second vehicle height signal generator and the signal of the vehicle height setting device applied via the switching means. The second comparison means compares the vehicle height with the vehicle height value, and the first comparison means sets the vehicle height value to the high level when the reference value of the 131J record width setter is larger than the high level vehicle height value. A first correction means for taking a vehicle height value and a second comparison means are used to lower the vehicle height setting device when the reference (h) of the vehicle height setting device is smaller than the low level vehicle height value. A second correction means for calculating a vehicle height value operates the vehicle height adjustment valve based on signals from the first and second correction means, the first and second comparison means, and the vehicle height sensor. 1vO) equipped with a control device.

The present invention will be explained based on examples. As shown in Figure 1, the overall configuration is a vehicle height setting device that generates a signal to set the vehicle height to an arbitrary height that exceeds the safety limit when driving.
and a pick-up type vehicle speed sensor 24 placed on the output shaft side of the transmission.A switching means 32 is operated based on the signal from this vehicle speed sensor υ24, and when the vehicle is stopped, the signal from the vehicle height setting device 22 is activated. While the money is directly added to the immediate device 39, while the money is being driven, the first $. Via the second comparison means 35, 36, the signal of the vehicle height setting device 22 is applied to the control device 39, either directly or after being corrected to a safety limit.

A signal corresponding to a high level of vehicle height generated when traveling is applied from the first signal generator 33 to the first comparing means 35,
When the signal from the vehicle height setter 22 is lower than the high level vehicle height value, the signal is sent to the second comparison means 36, and when it is higher than the high level vehicle height value, the signal is sent to the first correction means 37. The vehicle height value is corrected to a high level and applied to the control device 39.

Similarly, the second comparison means 36 is supplied with a signal from the second signal generator 34 that corresponds to a low level of vehicle height (2) corresponding to the permitted low level vehicle height, and the signal of the vehicle height setter 22 is If the signal is higher than the high value, the signal is directly corrected, and if it is lower than the low level vehicle height value, it is corrected to the low level vehicle height value by the second correction means 38, and the signal is corrected to the low level vehicle height value by the road control device 39. do.

The control PI3 device fii39 is the first. Second comparison means 35.
3G, 1st. The vehicle height adjustment valve C is operated based on the signals from the second correction means 37, 38, the switching fl'4G32Jj and the height sensor 4) 15, and the height set by the vehicle height setting device 22 is based on the store value. This is to maintain the vehicle height within a predetermined range.

As shown in FIG. 2, the left and right front wheel suspensions Δ and the left and right rear wheel suspensions '4A and B are exactly the same.

A well-known vine absorber 1 [consisting of a screw 1-3 fitted between a cylinder 2 and a cylinder 2] is disposed between an arm 1 and the vehicle body to support the wheels, and the cylinder 2 is connected to the vehicle body. Then, the U-rads 3a of the piston 8 are respectively coupled to the lower arms. Both end chambers of a cylinder 2 partitioned by screws 1 to 3 are connected via an electromagnetic throttle valve 4.

A spring 5 is supported between the vehicle body and the L1 arm. This air spring 5 is connected by an electromagnetic throttle valve 8 to a tank 6 and a spring wheel body 7 which can move up and down according to the deformation of the diaphragm. Tank 6 has conduit 9 and intake valve 10
The solenoid 10a is connected to the air pressure tank 13 or the atmosphere via the vehicle height adjustment valve C consisting of the exhaust valve 26 and the exhaust valve 26.
When the intake valve 10 is opened by energizing the solenoid 26a, compressed air is applied from the pneumatic tank 13 to the air spring body 7, raising the vehicle height.On the other hand, when the solenoid 26a is energized and the exhaust valve 26 is opened,
The structure is such that the air in the air spring body 7 is released to the atmosphere and the vehicle height is lowered.

In the case of the rear wheel suspension system B, the tanks 6 of the left and right air springs 5 are connected to the air pressure tank 1 via separate vehicle height adjustment valves C.
3a or the atmosphere, but this is because the vehicle height of the left and right wheels changes more greatly depending on the state of the cargo in the rear wheels than in the front wheels, so the vehicle height of the left and right wheels is adjusted separately.

In addition, in order to operate the front wheel brake 17, the air pressure tank 19 is connected to the brake valve 27, the pressure reducing valve 28, and the relay valve 1.
8 and is connected to the front wheel brake 17. Similarly, air pressure tank 19 is connected to rear wheel brake 17a via brake valve 27, pressure reducing valve 28 and relay valve 18.

The spring body 7 is used to detect the vehicle body load applied to each wheel.
An air pressure sensor 14 is provided to detect the air pressure inside the air pressure sensor 14, and this detection signal is applied to the microcomputer 20 as a digital signal. In addition, in order to detect the vehicle height,
A vehicle height sensor 15 is disposed between the spring body 7 and a suitable part on the axle such as the tank 6, and this detection signal is applied to the microcomputer 20 as a digital signal.

Further, the microcomputer 20 includes an air pressure setting device 21 consisting of a potentiometer for setting a reference value of the air pressure of the spring body 7, a vehicle height setting device 22 consisting of a potentiometer and a switch for generating a reference value setting signal, an engine rotation speed sensor 23, and a vehicle speed sensor 23. Signals from a sensor 24 and a brake sensor 25 that detects the amount of operation of the brake pedal are added as digital signals.

The microcomputer 20 operates the vehicle height adjustment valve C based on the signal from the vehicle height sensor +j15 and the signal from the vehicle height setter 22, adjusts the amount of air in the air springs 5 of the front wheels and the rear wheels, and adjusts the vehicle height. It is maintained within a predetermined range based on the reference value set by the high setting device 22.

Next, the operation when the device of the present invention is controlled by a microcomputer will be explained. 3-6 are flowcharts of the above-mentioned control program, and 11 to 57 show each step of the flowchart. When the engine key is operated, the operation part is set to pll.

In order to automatically set a dead value ±ΔhO that does not adjust the vehicle height even if the height of the vehicle height changes and the vehicle height changes in 912, and to prevent abnormal operation of the control device, each is set in the program. Set the standard setting @hoo and the standard setting value α, and use this as the temporary base i! = load as a value.

The vehicle speed is detected by the vehicle speed sensor 1124 in p13, and the vehicle speed is detected in p14.
11 is determined whether the signal of the vehicle speed sensor 24 is 0 or not. When the vehicle speed is O, it is determined in p15 whether the state where the vehicle speed is 0 continues for 1 second.

This confirms that the vehicle has come to a complete stop and prohibits changes to the vehicle height reference value ho while the vehicle is running.

plG determines whether the switch of the setting signal circuit for the vehicle height reference value ho is closed. This switch is self! I
The story of the J return type: ``The vehicle height standard value is 1+.

11- Prevents the vehicle from changing regardless of the driver's will.

If the setting circuit for the vehicle height reference value 1+o is closed, the vehicle height setting value hot@ selected by the driver using the 11t% setting device 22 is read in p17, and the setting value 1111 is set in p18.
Set hOl as the new vehicle height standard value 1+o, p19
Set flag a to cellar 1. In this way, the vehicle height standard value.

Settings and changes can be made only when the vehicle is stopped, and while the vehicle is stopped, it is possible to easily load and unload cargo by adjusting the loading platform to the height of Bran 1-Bohm.

The vehicle height 11 while the vehicle is running is adjusted at two points, one on the front wheels and the other on the rear wheels, taking into consideration things such as unevenness of the load. That is, p20
The vehicle height hFR is detected by the vehicle height sensor 4J15 of the right front wheel at p21, and the vehicle height hF is detected by the vehicle height sensor 15 of the left front wheel at p21.
L is detected, and the average vehicle height hF of the right front wheel and the left front wheel is determined in p22. Next, as shown in FIG. 4, the program enters a vehicle height adjustment subroutine to be described later at p23, and controls the front wheels. At p24, the vehicle height hRR is detected by the vehicle height sensor 15 of the right rear wheel. 1) At step 25, the vehicle height adjustment subroutine is entered, and frill tH is performed for the 0-side rear wheel. Similarly,
At step 926, the vehicle height sensor "15" for the left rear wheel detects the vehicle height, and at step p27, the vehicle height adjustment subroutine is entered to control the left rear wheel.

The vehicle height adjustment 1 knob routine is programmed as shown in FIG. At p28, the vehicle height adjustment subroutine is entered, and 1) at step 29, it is determined whether the vehicle speed is 0 or not. If the vehicle speed is not O, proceed to p45. When the vehicle speed is O, the engine rotation speed sensor 23 determines whether or not the re-engine is being driven at GJ and D30.

When the engine is running, p31 sets the dead value Δ1)0, which does not adjust the vehicle height even if the vehicle height changes, to ±α<
For example, 2 to 3 races), and after the new vehicle height standard value ho is set on page 18 and the flag a is set,
At 32, the average vehicle height of the front wheels hF and the vehicle height of the left and right rear wheels is 11
It is determined whether RL and 11RR have once entered the range from the vehicle height reference value 110 to the dead value ΔhO by resetting the flag a.

Front/rear wheel height 11F, IIRL, IIRR
is set Y [IJ] +10-! = ΔhO once, flag a is reset in p43, and after that G
, t In p33, the dead time 1 in which the vehicle height is not adjusted even if the vehicle height changes is set to t2 (approximately 0.1 seconds), and in p34, the average middle height in seconds is determined.

Front and rear wheel height hp in p32, IIRL,
If IIRR has never fallen within the setting range [10±Δ110, flag a is set to 1~, so p
Proceed to 37.

If the engine is stopped at p30, in order to suppress the consumption of compressed air due to vehicle height adjustment, set the dead value △ho, which does not perform vehicle height adjustment even if the vehicle height changes, at p35.
β (6 to 10 mm), p3G sets the dead time t in which the vehicle height is not adjusted even if the vehicle height changes to t3 (2 to 5 seconds), and p34 sets the average Il' for 1 second! Seek high.

Next, on p37, calculate the actual vehicle height hF, hRL, h
It is determined whether RR is so far from the vehicle height reference value hO that it exceeds an insensible value ΔhO. Actual vehicle height hF, hRL,
If Ilr+n is lower than 110+Δho, then p
Actual vehicle height hF, IIFIL, IIRR at 38
It is determined whether or not the vehicle height is so low as to exceed the insensible value ΔhO from the vehicle height reference value ho. And the actual vehicle height 'nF, hR
If Ll hRRh<ha-ΔhO is lower than 1 (then close the exhaust valve 26 in p39 and close the intake valve 1 in p40
Open 0 to raise the vehicle height. Actual vehicle height hp in p38
, hRl, 11RR is higher than 110-ΔhO, the exhaust valve 26 is closed at p43, and the intake valve 10 is kept closed at p44. Also, in p37, the actual vehicle height is 11F, hRLl hBR is hO + Δho
If the vehicle height is higher than that, the intake valve 10 is closed in step 1141, and the exhaust valve 26 is opened in step p42 to lower the vehicle height. In this way, the average vehicle height h of the front wheels is calculated in the vehicle height adjustment subroutine.
F1 vehicle height hRL of left rear wheel and small height hRR of right rear wheel
are detected, and the actual vehicle height hF, h, , h
Control is performed so that RR is within the range of the dead value ±ΔhO from the vehicle height reference value bo, and the process returns from p4G to p14, and the above processing is repeated.

In addition, as mentioned in "-", after rewriting the height hO@ on page 18, the actual vehicle height h1, IIFL, 11 is shown on page 32.
While RR is still not within the setting range 1) 0±8ho,
Don't calculate the average vehicle distance for 1 second until the setting range hO±ΔhO is reached, and proceed directly to page 37, but the actual speed ^hF,
For 1η when 11RL and IIRR are within the setting range ho±8h, calculate the average vehicle height for 1 second to remove the influence of vehicle body vibration, and this average vehicle height falls within the setting range ho±△ho.
It determines whether or not it is present and controls it.

Next, if the vehicle speed is not O at p29, the vehicle height adjustment while the vehicle is moving is controlled by the progear 11 shown in FIG. First, the vehicle height standard value hO set while stopped on page 47
is a high-level reference value h+ (as shown in FIG. 7, it is determined by taking into account the change in vehicle height due to vibrations during driving) that does not cause any hindrance to driving. If the vehicle height reference value ho set while the vehicle is stopped is larger than the high level reference value h1, the high level reference value lI+ is set as the vehicle height reference value hO in p50.In addition, the vehicle height reference value If 110 is less than the high level reference value, then
At p48, it is determined whether the vehicle height reference (direct ho) is smaller than the low level reference value h2.

When the vehicle height reference value ho set while the vehicle is stopped is smaller than the low-level reference value h2, the low-level reference value h2 is set as the vehicle height reference tP value hO in 949. Then, in p51, each value is continued as the vehicle height base tli and hO.

Next, in p52, the insensitive value ΔhO, which does not adjust the vehicle height vd even if the vehicle height changes, is set to the original setting value α, and in p53, the warning light 29 indicates that the vehicle height standard value ho when the vehicle is stopped is suitable for driving. The value is not correct and is being corrected. Alternatively, the clutch may not be engaged or the brake pedal may be operated such that the accelerator pedal cannot be depressed.

The reference value hO of the vehicle height while stopped is low in p48
If it is lower than 2, it is determined in p54 whether flag b has been set to 1 or not. If flag b is set to [-], p55 indicates the actual vehicle height hF.

Vehicle height base set while the 11RR is stopped* fF
It is determined whether or not it is within the range of the insensitive value ±Δl+o from xho.

If the actual vehicle height hF, hRLl hRFl exceeds the range from the vehicle height reference value hO to the dead value ±Δ1)0, the warning light 29 is activated in p53. Also, the actual vehicle height hF.

1) Tortoise+') If RR is within the range of the insensible value ±ΔhO from the vehicle height standard value ho when the vehicle is stopped, flag b is set in p56.
performs the reset 1-, and stops the operation of the warning light 29 at p57. Then, the process returns to tp33 shown in FIG.

In addition, if the flags 1~ are not set on page 54, return to page 33 shown in Fig. 5, calculate the average vehicle height of the front wheels and rear wheels in seconds, and calculate the vehicle height reference value hθ.
, operate the exhaust valve 2G or the intake valve 10, and set the actual vehicle height hF r "RL + hRR to the vehicle height reference value b.
I'm going to punish you for what you do.

As described above, the present invention automatically lowers the vehicle height by operating the vehicle height setting device from the driver's seat, making it easier for passengers to get off the bus in the case of a bus, and in the case of a rack. The height of the loading platform can be adjusted to w1 to facilitate loading and unloading. Therefore, when the vehicle starts, even if the height of the vehicle while the vehicle is stopped exceeds the safe limit that would pose a hindrance to driving, the vehicle height setting value is automatically adjusted to the safe limit. This solves problems such as when the driver neglects to correct the vehicle height, the vehicle height is too low and obstacles on the road hit the floor, or the vehicle height is too high and the vehicle becomes unstable. .

Furthermore, since the vehicle height of the rear wheels is adjusted separately for the left and right sides, the vehicle body can be maintained almost horizontally even when cargo is stacked on one side.

In the above embodiment, the vehicle height is adjusted using one vehicle height sensor for the front wheel and two vehicle height sensors for the rear wheel.
It is also possible to arrange the sensors at one point at a time, or at two points on the front wheels and one point on the rear wheels, and control the vehicle height while the vehicle is stopped and while the vehicle is running based on the signals from these vehicle height sensors.

[Brief explanation of drawings]

Fig. 1 shows the schematic structure of the vehicle tII adjustment device according to the present invention.
Figure 6 is a flowchart explaining the software for controlling the vehicle height adjustment valve, and Figure 7 is a diagram explaining the vehicle height adjustment effect when the vehicle is stopped and while the vehicle is running. A: Front wheel suspension B: Rear wheel Suspension system C: Vehicle height adjustment valve 1: Shock absorber 4 near 1Jj throttle valve 5:
Air spring 6: Tank 7: Spring body 10: Intake valve 1
3.13a: Air pressure tank 15: Vehicle height sensor 20
: Microcomputer 22: Vehicle height setting device 23: Engine speed sensor 24: Vehicle speed sensor 26: Exhaust valve 2
9: Warning light 32 switching means 33: First vehicle height signal generator 34: Second vehicle height No. 48 generator 35.
36: 1st. Second comparison means 37.38: 1st ° 2nd
Amendment means 39: Control device patent applicant Patent attorney Itzu Jidosha Co., Ltd. Agent Toshio Yamamoto Figure 2 Complaint 3 Ward Procedure 7 Fu Seishi (spontaneous) November 1, 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi Tono 1 , Indication of the case 1982 Patent Application No. 171185 2 Name of the invention Vehicle height adjustment device 3 Person making the amendment Relationship to the case Patent applicant address 6-22-10, Minami-Oi, Parts Ward, Tokyo Name <
017) Isuzu Motors Co., Ltd. Representative Toshio Okamoto 4, Agent Address Atago Building, 3-16-3 Nishi-Shinbashi, Minato-ku, Tokyo Telephone (43B) 158B 6. Number of inventions increased by amendment 7, Subject of amendment Drawing 8 , Details of the amendment "Figure 5" of the drawings will be amended as shown in the attached sheet. X22＼Figure 51

Claims (1)

[Claims] In a suspension system that controls vehicle height by adjusting the amount of air in an air spring disposed between a vehicle body and an axle using a vehicle height adjustment valve, a vehicle height sensor IJ- disposed on the air spring and a vehicle speed a sensor, a vehicle height setter that generates a reference value for maintaining the vehicle height within a predetermined range, and a vehicle height setter that directly controls the signal of the vehicle height setter when the vehicle is stopped based on the signal from the vehicle speed sensor.
] during driving (first and second comparison means), a first vehicle height signal generator that generates a signal corresponding to a high level of vehicle height that is permissible during traveling; 1. a second vehicle height signal generator that generates a signal corresponding to a permissible low level vehicle height; and a signal of the first vehicle height signal generator and the vehicle height setter that is applied via the switching means. the first comparing means for comparing the signal from the second vehicle height signal generator and the signal from the vehicle height setting device applied via the switching means; , a first correction means for setting the reference value to the high-level vehicle height value when the reference value of the vehicle height setting device is larger than the high-level vehicle height value in the first comparison means;
In the second comparison means, the said person? 111.: a second correction means for setting the reference value to a low level vehicle height value when the R standard value of the 1 setter is smaller than the low level vehicle height 61;
A vehicle height adjustment device characterized in that it comprises a second correction means, the first and second comparison means, and a control device that operates the vehicle height adjustment valve based on a signal from the vehicle sensor. Device.