JPH02237811A - Car height control device - Google Patents

Abstract

PURPOSE:To enhance the running stability by equipping a car with a car height control device, and thereby inclining the car body forward more at the time of the headlights being Off than On while car height decremental control is being implemented. CONSTITUTION:A control unit 25 receives signals from a car height sensor 22, car speed sensor 27, and headlight switch 32 and performs car height decremental control for a main pneumatic spring chamber 3, functioning also as a car height adjusting fluid chamber, of a shock absorber 1 when the car speed is over the set value. If at this time the headlight switch 32 is being off, i.e., during daytime with light out of service, the car body is controlled into forward inclining attitude more than when the light is turned On. At nighttime with the light On, sufficient projecting distance shall be obtained with no such inclination forward. This enhances running stability.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a vehicle height control device for vehicles such as automobiles. (Prior Art) Conventionally, in vehicle suspension systems that can adjust the vehicle height, driving stability is improved by lowering the vehicle's center of gravity by lowering the vehicle height when driving at high speed based on the detection signal of the vehicle speed sensor. (2) Vehicles with improved aerodynamic characteristics are known.It is also known that the aerodynamic characteristics are improved by tilting the vehicle body forward during high-speed driving.

[Problem to be solved by the invention]

Therefore, when driving at high speeds, it is preferable to lower the vehicle height and lean the vehicle forward, but this poses the problem that the illumination distance when the headlights are turned on becomes shorter. become.

This invention was made to solve the problems mentioned in -L, and ζ' performs appropriate vehicle height control when driving at high speeds, whether during the day or at night (passing through a tunnel between A and B). The object of the present invention is to provide a vehicle height control device that can improve the running stability of a vehicle as much as possible.

[Means to solve the problem]

A vehicle height control device according to the present invention includes a vehicle height adjustment device that can separately adjust vehicle height on a front wheel side and a vehicle height on a rear wheel side, a vehicle speed sensor that detects vehicle speed, and a vehicle speed exceeding a set vehicle speed using the vehicle speed sensor. A vehicle height control device includes a vehicle height control section that outputs a control signal to the vehicle height adjustment device to perform vehicle height lowering control when a vehicle speed is detected. [-The vehicle height control section includes a detection means,
When executing the vehicle height lowering control described in "2.
When the detection means detects that the headlights are off, a control signal is sent to set the vehicle height L to cause the vehicle body to lean more forward than when it detects that the headlights are on. This is a vehicle height control device characterized by outputting to an adjustment device.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a schematic diagram of a privately-owned vehicle equipped with a vehicle height control device, Figure 2 is an overall configuration diagram of the vehicle height control device, and Figure 3 is a diagram showing vehicle speed, headlight switch, rear wheel height, and rear wheel height control. FIG. 4 is a flowchart explaining the operation. First, as shown in Fig. 1, front air suspension units FS (FSIFS2
) is interposed, and a rear air suspension unit RS (RSIRS2) is interposed between both left and right ends of the rear wheel BA side axle and the vehicle body B side member.Hl is the head It is light. These air-suspensing units FSI/FS2.
Since RSI and RS2 each have almost the same structure, the air suspension unit will be designated by the symbol S as shown in Fig. 2, except when specifically explaining the front I single use and rear air suspension units. The explanation will be made using the following figure, and only the parts necessary for vehicle height control will be illustrated and explained.

In other words, these Airzas Benshigon units S are
It incorporates a strut 1 type damping force switching type shigok absorber 1, and this shikku absorber 1 has a cylinder attached to the front wheel FA side or the rear wheel BA side,
A piston is slidably inserted into this cylinder, and the cylinder moves up and down with respect to the piston rod 2 in response to the up and down movement of the wheel, thereby providing a damping function that corresponds to the position of the shutter in the shock absorber 1. This makes it possible to effectively absorb shock. By the way, a main air spring chamber 3 which also serves as a vehicle height adjustment fluid chamber is disposed coaxially with the piston rod 2 in the upper part of this straight-type Tsukuri absorber 1, and a part of this main air spring chamber 3 Since it is formed of a bellows 4, the piston rod 2 can be moved up and down by supplying and discharging air to the main air spring chamber 3.

Further, a sub air spring chamber 5 is disposed coaxially with the piston rod 2 directly above the main air spring chamber 3 .

Further, the outer wall of the shock absorber l is provided with a spring receiver 6a facing in the - direction, and the outer wall of the sub air spring chamber 5 is provided with a spring receiver 61) facing downward.
A coil spring 7 is loaded between these spring supports 6a and 6b.

Further, these air spring chambers 3 and 5 are connected to each other via a communication passage 9 bored across the drive bin 8 and the piston rod 2, and this communication passage 9 includes a spring constant switching machine lateral E. An on-off valve 10 is interposed.

This on-off valve 10 includes a first valve portion 10a that cuts off communication between the auxiliary air spring chamber 5 and the communication passage 9, and a main air spring chamber 3.
A second valve portion 10b that cuts off communication with the jm path 9.
It is composed of:

Therefore, when the valve portion 10a is in the open mode, the main air spring chamber 3 and the auxiliary air spring chamber 5 are brought into communication, the spring constant can be made small (soft), and the valve portion 10a
is in the closed mode, the main air spring chamber 3 and the sub air spring chamber 5
The spring constant can be made larger (harder) by putting this in a cut-off state.

That is, by rotating the drive bin 8, the on-off valve 10 can be opened and closed, and by this opening and closing, the spring chamber capacity can be changed.

By changing this spring chamber capacity, the spring constant of the suspension can be changed. As soon as the vehicle height adjustment of the automobile is carried out using the configuration shown in FIG.
As shown in FIG. 2, compressed air for vehicle height adjustment is supplied from a compressor II as a compressed air generator to a dryer 12, a joint 13, a rear sole/noid valve 14,
A front solenoid valve 15, piping 16 connecting these, and a communication passage 17 in a partially pipe-shaped drive bin.
It is designed to be supplied to each ZASUBENSHIGONSUSOTOS via the following.

The compressor 11 compresses the air sent from the air cleaner 18 and supplies it to the dryer 12. The compressed air dried by silica gel etc. in the dryer 12 is as shown by each solid arrow in FIG. , is supplied to The Suspension Unit 1/S. Furthermore, when the compressed air is exhausted from the suspension unit S, the compressed air is released to the popular side via the exhaust solenoid valve 19, as shown by each broken line arrow in FIG.

Note that a reserve tank 20 is connected to the dryer 12, and a portion of the compressed air is transferred to this reserve tank 20.
Air is supplied from the air to each suspension unit S via the air supply solenoid valve 21.

Further, as shown in FIG. 2, a vehicle height sensor 22 is provided, and this vehicle height sensor 22 is a front vehicle height sensor that is attached to a lower arm 23 on the front right side of the vehicle and detects the front vehicle height of the vehicle. 22F, and a rear vehicle height sensor 22R that is attached to a lateral rod 24 on the rear left side of the vehicle to detect the rear vehicle height of the vehicle, and vehicle height adjustment control is performed from these vehicle height sensors 22F and 22R. A front vehicle height detection signal and a rear vehicle height detection signal are supplied to the controller 1/roll unit 25 as a part.

In addition, each sensor 22F. 22
R is one of the ball IC element and the magnet on the wheel FA side,
The other one is attached to the vehicle body B side to detect the distance from the normal vehicle height level and the low or high vehicle height level, respectively.

Furthermore, the speedometer 26 has a built-in vehicle speed sensor 27, which detects the vehicle speed and supplies a detection signal to the control unit 25. A reed switch type vehicle speed sensor is used, and an electronic speedometer uses a transistor oven collector output type sensor.

Further, an acceleration sensor 28 is provided as a vehicle body posture sensor for detecting changes in the posture of the vehicle body, and this acceleration sensor 28 is configured to detect changes in pitch, roll, and yaw body posture on the automobile spring. For example, when there is no acceleration, the weight is in a hanging state, and the light from the light emitting diode is blocked by the shielding plate and does not reach the photodiode, so it is possible to detect that there is no acceleration. There is.

When acceleration acts on the front and back, left and right, or up and down, the weight tilts or moves,
The acceleration state of the vehicle body is detected.

The reference numeral 29 in FIG. 2 is a solenoid mechanism, which rotates the drive bin 8 to a predetermined position by driving a soft solenoid in response to a signal from the control unit 25 to shift from the hard state to the soft state. It also has a function of rotating the drive pin 8 in the opposite direction to a predetermined position by driving the hard solenoid, thereby shifting from the soft 1 state to the hard state. Also, the symbol I-,
F stands for the engine room (to the left of the broken line LF) and the passenger compartment (
The broken line indicates the boundary between LF and LR), and LR indicates the boundary between the passenger compartment and 1.
It shows the border with the rank room (to the right of the broken line L R). Further, reference numeral 30 indicates a bump stop for preventing damage to the wall surface of the air spring chamber 3 due to the relative rise of the cylinder of the cylinder of the cylinder absorber 1 on rough roads or the like. 31 is Banteri 32 is He2
It is a switch that turns on and off the light I{L.
receives vehicle height detection No. 13, tonnage speed detection signal, and headlight ON/OFF signal from the vehicle height sensor 22, vehicle speed sensor 27, and heno l' light switch 32, respectively, and also stores a memory for a suspended sentence flag and a vehicle height flag. It has a built-in memory, timer, control unit, etc. to set the vehicle height detection time, etc., and it can respond to the contents of the other line grace flag and vehicle height flag used to shorten vehicle height control. , the vehicle height is controlled after a long period of time as in the past.

Next, the operation of the apparatus configured as described above will be explained with reference to FIG. 3 and the fourth section. Controller 1 roll unit [25] Vehicle height sensor 22, vehicle speed sensor 27, and headlight switch 32 generate vehicle height detection signals every moment.
A vehicle speed detection signal and a headlight on/off signal are supplied. Therefore, as shown in FIG. 3, the control 1/roll unit 25 detects the front speed when the vehicle speed detection signal is low (■). The target vehicle height for both the rear wheel vehicle height is set to the normal vehicle height, and the vehicle height detection time, which is completely different from the actual vehicle height and the target vehicle height, is set as ■. Next, when the vehicle speed increases and the vehicle height detection signal determines that the vehicle speed is high, the hend light switch 32 is turned off to lower the vehicle height of the front wheels to improve the aerodynamic characteristics of the low vehicle height. Furthermore, when a headlight ON signal is input due to passing through a tunnel at high speed, the target height of the rear wheels is set to a low vehicle height in order to make the optical axis of the headlight parallel to the road surface, and the vehicle height detection time is However, since the vehicle height detection time is short after the control starts, the vehicle height may temporarily match the target vehicle height due to unevenness of the road surface, etc. Even if the vehicle height matches the vehicle height and the control is stopped, the vehicle height detection time is shortened and the re-vehicle height control start time is accelerated, the vehicle height is re-controlled to the normal vehicle height, and the re-vehicle height control is completed. After that, return to the normal long vehicle height detection time (long 11). In terms of time, it is 1.5 seconds at short times and 1.5 seconds at low vehicle speeds.
It may be 0 sec (long r), 20 sec at high vehicle speed, or 4.5 sec at short time, 1 at low vehicle speed.
3 seconds, or 30 seconds at high vehicle speed.

Next, a series of controls as shown in L below will be explained according to the flowchart of FIG. First, it is determined whether the vehicle speed is high or low at Sl, and if the vehicle speed is low, '. The program proceeds to step 32, sets the vehicle height detection time to 1 (1), performs other controls in step S14, and returns to star 1.

On the other hand, in the case of a high city speed, the process proceeds to S3, and it is determined whether the execution flag, which will be described later, is 1 or 0 to determine whether the vehicle height detection time is set to be long (■) or not. If the sentence is not suspended (the execution flag is "0"), the process proceeds to step 34. In S4, it is determined whether there is a change in the headlights from on to off or from off to on, and if there is no change, the process proceeds to S5, where the vehicle height detection time is set to long (II), and the process proceeds to S14. ．． If it is determined in S4 that the headlights have changed from on to off or from off to on, the process proceeds to S6 and changes the target vehicle height to a value corresponding to whether the headlights are on or off, and sets the vehicle height detection time to a short value in S7. , it is determined at 38 whether the target vehicle height and the actual vehicle height match, and the process waits at S8 until they match. Thus, if they match, S
At step 9, set the axis row flag to ``'1'' and end the process.S3
If the execution flag is ``1'' (vehicle height detection time is already set to short), the vehicle height will temporarily lose due to unevenness of the road surface, stop, and start re-adjusting the vehicle height. The SIO determines whether or not the vehicle height adjustment is to be performed, and if the vehicle height adjustment is not to be started again, the SIO
Proceed to l4. If re-adjustment of vehicle height is to be started, proceed to Sll and wait in S11 until this is completed.

When the vehicle height adjustment is completed again, the process goes to 312 and the execution flag is cleared to '0゛. In 313, the vehicle height detection time is set to long (n), and the process goes to S14 to start and return to the control 1/roll unit 25. The vehicle height control signal from compressor 1 1 . '． 2, and 6.'': Controls the opening of only the necessary solenoid valves 14, 15, 19, 21, etc., and thereby controls the supply and exhaust of fluid to the suspension unit S. This is to control the vehicle height by 4Bt.

〔Effect of the invention〕

According to this invention, since vehicle height lowering control is executed when the vehicle is traveling at a high speed higher than the set vehicle speed, the center of gravity of the vehicle is lowered and the aerodynamic characteristics are also improved. This improves driving stability, and when driving at high speeds above the set vehicle speed in the daytime when the headlights are off, the vehicle body becomes more stable than at night when the headlights are on. Since it is in a forward leaning state, the aerodynamic characteristics of the vehicle can be significantly tilted toward C when driving at high speed during the day, and when driving at high speed at night, it is possible to obtain an appropriate irradiation distance of 1. It has the effect of solving the problems of conventional devices that have been developed6.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of an automobile equipped with a vehicle height control device according to Saiko's invention; Figure 2 is an overall configuration diagram of the vehicle height control device;
The figure is a timing diagram showing the relationship among vehicle speed, steering control, rear wheel height, rear wheel suspension control, and vehicle height detection time, and FIG. 4 is a flowchart for explaining the operation. FS (FSI, FS2)...Air suspension unit 5-unit for Freon l, RF (RFI.RF2)...
・Air suspension for rear unit 27, S is air suspension Konit I, HL...Headlight, 1.
...Shock absorber, 3...Main air spring chamber, 11
...Combiner, 12...Dryer, 14, 15
．． t9, 21... Solenoid valve, 2222F
22R...Vehicle height sensor, 25...Control 1 roll unit, 27...Vehicle speed sensor, 31...Vasoteri 3
2...Hendry L switch. Agent Masuo Oiwa Figure 1, B FA; Pre-export RA Niiki Shinjiru HL; Hendo 2ite Figure

Claims (1)

[Claims] A vehicle height adjustment device that can adjust the vehicle height of the front wheels and the vehicle height of the rear wheels separately; a vehicle speed sensor that detects vehicle speed; A vehicle height control device comprising a vehicle height control section that outputs a control signal to an adjustment device to execute vehicle height lowering control, comprising a light detection means for detecting whether a headlight is turned on or off,
When the vehicle height control section detects that the headlights are off by the light detection means when executing the vehicle height lowering control, the vehicle height control section detects that the headlights are on. A vehicle height control device, characterized in that the vehicle height control device outputs a control signal to the vehicle height adjustment device to cause the vehicle body to lean forward more than the vehicle height.