JPS60255516A - Electronic-controlled suspension apparatus - Google Patents

Abstract

PURPOSE:To prevent the increase of the consumption of battery power source by setting the aimed car-height high only for a set time even if the judgement for bad road is released after bad road traveling is judged and the aimed car-height is set high. CONSTITUTION:In the judgement for bad road, the timing on a 2sec timer is read into a control unit 25, and also the output signal of a car-height sensor 22 is read into the unit 25, and judgement is performed according to the fact that the car-height lower than a lower car-height level is outputted at least two times or not. The compressed air for adjusting car height is supplied into each suspension unit S from a compressor 11 through a dryer 12, joint 13, rear and front solenoid valves 14 and 15, etc. Then, the release after the establishment of the judgement of bad road is judged, and when the judgement is YES, the aimed car-height is set high for 12sec, and thus increase of the consumption of battery power source can be prevented.

Description

[Detailed Description of the Invention] The present invention provides a vehicle height control device that can perform vehicle height control in three stages: "high,""medium," and "low." The present invention relates to an electronically controlled suspension system that continues to set a target vehicle height high during the set time after the bad road determination is canceled.

Conventionally, when driving on rough roads, the purpose of raising the vehicle height is to increase the vehicle's minimum ground clearance, reduce contact between the road surface and the vehicle body, improve drivability on rough roads, and reduce damage to the vehicle body. A vehicle height control device is known. A set time (for example, 2 seconds) that determines whether the vehicle is traveling on such a rough road.
Depending on the condition of the road, the road is judged to be bad and the road is good. Not only is the height lowering adjustment repeated alternately, making it impossible to adjust the vehicle height smoothly at high vehicle heights, the air consumption increases and battery power consumption increases, and the light indicating that the vehicle height is being adjusted is displayed. If equipped, there is a problem in that the cough lamp repeatedly turns on and off, reducing the reliability of the system.

This invention was made in view of the above points, and its purpose is to install a vehicle height control system that can perform vehicle height control in three stages: "high,""medium," and "low." After it is determined that the vehicle is traveling on a rough road and the target vehicle height is set high, even if the rough road determination is canceled, the target vehicle height is set high for the set time to prevent an increase in battery power consumption. The object of the present invention is to provide an electronically controlled suspension device that can perform the following steps.Hereinafter, an embodiment of this n will be described with reference to the drawings. FIG. 1 is a schematic diagram of a car equipped with this device.

As shown in FIG. 1, a front air suspension unit ps (Fsz) is provided between the left and right ends of the front wheel FA side axle and the vehicle body B side member.

Fl) 2) is interposed between the left and right ends of the rear wheel BA side axle and the vehicle body B side member, respectively.
) is interposed.

These air suspension units) F, SZ.

Fe2. Since the Re 1 and R82 each have almost the same structure, the air suspension units will be designated by the symbol S as shown in Fig. 2, unless the front and rear suspension units are specifically explained. 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 air suspensions (22)S are:
This shock absorber 1 incorporates a strut type damping force switching type shock absorber 1.
It has a cylinder attached to the A side or the rear wheel BA side, and a piston that is slidably inserted into this cylinder.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 generating a shock. absorber 1
It has a damping function depending on the position of the shutter inside, making it possible to effectively absorb shock.

Incidentally, 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 the shock absorber 1, and a part of this main air spring chamber 3 is provided with 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 1 is provided with a spring receiver 6a facing upward, and the outer wall of the auxiliary air spring chamber 5 is provided with a spring receiver 6b facing downward. 6a.

A coil spring 7 is loaded between 6b.

Furthermore, these air spring chambers 3 and 5 are connected to each other via a communication passage 9 bored in a control rod rod 8 which is rotatably inserted into the pistone rod 2. An on-off valve 10 constituting a spring constant switching mechanism is interposed in the communication path 9.

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 97, and a main air spring chamber 3.
The second valve part 10b is configured to cut off communication between the valve and the communication passage 9.

Therefore, when the on-off valve 10 is in the open mode, the main air spring chamber 3 and the auxiliary air spring chamber 5 can be brought into communication, and the spring constant can be made small (soft), and the on-off valve 10 is in the closed mode. In this case, the main air spring chamber 3 and the auxiliary air spring chamber 5 can be cut off to increase the spring constant.

That is, by rotating the control rod 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.

Furthermore, a control valve 8a is provided at the lower end of the control rod 8, which can change the orifice area of the piston la of the shock absorber I. This control valve 8
a is to reduce the damping force by reducing the orifice area of the piston 1a by using the control rod 8 when the on-off valve 10 is in the open mode, and to reduce the orifice area of the piston 1a when the on-off valve 10 is in the open mode. It is configured to increase the damping force.

Thus, the vehicle+%g4 adjustment of the automobile is carried out by the configuration shown in FIG. That is, as shown in FIG. 2, compressed air for the treatment of serious illnesses is distributed from a compressor 11 as a compressed air generator to a dryer 12, a joint 13, a rear solenoid valve 14, and a front solenoid valve 15.
The water is supplied to each suspension 22) S through piping 16 connecting these parts and a connection port I7 that communicates with the communication path 9 of the control unit, which is partially pipe-shaped.

The compressor 11 compresses the air sent from the air cleaner 18 and supplies it to the dryer Z2.The 8E compressed air dried by silica gel etc. in the dryer I2 is indicated by each solid line arrow in FIG. is supplied to the suspension unit S. Further, when the compressed air is exhausted from the suspension unit 8, the compressed air is released to the atmosphere through the exhaust solenoid valve 19, as shown by each broken line arrow in FIG.

A reserve tank 20 is connected to the dryer 12, and a portion of the compressed air is supplied from the reserve tank 20 to each suspension unit S via an 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 attached to a lower arm 23 of the front right suspension of the vehicle to detect the front vehicle height of the vehicle. A height sensor 22F and a rear vehicle height sensor 22 that is attached to the lateral rod 24 of the rear left suspension of the vehicle and detects the rear vehicle height of the vehicle.
These vehicle height sensors 2
Vehicle height adjustment control unit from 2F and 22R! A front vehicle height detection signal and a rear vehicle height detection signal are supplied to the control unit 25.

Each sensor 22F in the vehicle height sensor 22.

22R connects one of the Hall IC element and the magnet to the wheel FA.
and the other side is attached to the vehicle body B side to detect the distance from the normal vehicle height level and the low vehicle height or high vehicle height level, respectively. Note that the vehicle height sensor may be of any other type, for example, one using a phototransistor.

Generally, the speedometer 26 has a built-in vehicle speed sensor 27, and this sensor 27 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 open collector output type sensor using a transistor is used in an electronic speedometer.

Further, a vehicle body attitude sensor and an acceleration sensor 28 for detecting changes in the attitude of the vehicle body are provided, and this acceleration sensor 28 is adapted to detect changes in the attitude of the vehicle body such as pitch, roll, and yaw 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 the structure is such that it can be detected that there is no acceleration. ing.

When the acceleration acts forward and backward, left and right, or up and down, the weight tilts and moves, resulting in
The acceleration state of the vehicle body is detected.

32 is a steering sensor that detects the rotational speed of the steering wheel 33, that is, the steering speed; 34 is an accelerator sensor that detects the operation speed of an accelerator pebble of the engine (not shown); and 35 is a three-way switching valve 36 connected to the reserve tank 20. 1 is a pneumatic drive mechanism that communicates with the control rod 8 and rotates the control rod 8, and the three-way switching valve 36 has a position where the pneumatic drive mechanism 35 and the reserve tank 2o communicate with each other, and a position where the control unit 25 communicates with the pneumatic drive mechanism 35 and the reserve tank 2o. It has the function of selecting either the pressure type drive mechanism 35 or the position communicating with the atmosphere, thereby rotating the control rod 3 in the opposite direction to a predetermined position and shifting from the soft state to the hard state. In addition, it is also possible to use an air cylinder type drive mechanism instead of the solenoid type drive mechanism 2o. Furthermore, the symbol LF indicates the boundary between the engine room (left of the broken line LF) and the single room (between the broken lines LF and LR), and LR indicates the boundary between the passenger compartment and the trunk room (the broken line L).
It marks the border between R and Shi (to the right). Further, the reference numeral 3° indicates a bump stopper for preventing damage to the wall surface of the main air spring chamber 3 due to the relative rise of the shock absorber I on rough roads or the like. The code string is a mode selection switch as a high vehicle height selection switch. By the way, this mode selection switch 31 can switch between an auto mode in which the vehicle height is automatically controlled to a normal vehicle height or a low vehicle height, and a high mode in which the vehicle height is controlled to a high vehicle height.

Next, the operation of an embodiment of the present invention configured as described above will be described. First, the overall operation will be explained using the flowchart shown in FIG. First, in step s1, as an initial setting, the vehicle height adjustment i is set to an auto mode in which the vehicle height is automatically set to a "medium" or "low" vehicle height. Then, set the target vehicle height to normal, and set the height to medium.
The vehicle height is set.

Next, in step S2, it is determined whether or not the road surface on which the vehicle is traveling is a rough road, which will be described in detail later with reference to FIG. Then, in step S3, the fifth
A target vehicle height determination, which will be described in detail later with reference to the drawings, is performed, that is, it is determined how high the target vehicle height should be set. Then, the process proceeds to step S4, where the vehicle height signal from the vehicle height sensor z2y (2tR) is read into the control unit 25. And 1. In step S5, the vehicle height sensor 22F (
22R) It is determined whether the vehicle height that can be detected is equal to the target vehicle height set in step S3. If it is determined "NO" in this step S5, step S6
Then, the vehicle height adjustment is started toward the target vehicle height.

For example, if the vehicle height detected in step S4 is lower than the target height, the vehicle height is raised by supplying air to the main air spring chamber 3 of the valley suspension unit. On the other hand, if the vehicle height detected in step S4 is higher than the target vehicle height, air is exhausted from the main air spring chamber 3 of each suspension unit. Then, return to step S2 above,
When the vehicle height becomes equal to the target vehicle height in step S5, the process proceeds to step S7, and the vehicle height adjustment in step S6 is completed.

Next, the rough road determination performed in step S2 in FIG. 3 will be described in detail with reference to the flowchart in FIG. 4. Finally, in step S11, the control unit 25 reads the time of the two-second timer, which is supposed to count two seconds.

Then, in step S12, it is determined whether two seconds have been counted by the two second timer. If the determination in step B12 is "NO", the process proceeds to step B'13, where the output signal of the vehicle height sensor 22F (, ?2R) is read into the control unit 25, and the process proceeds to step S14, where the acceleration If (G) sensor The output signal of 28 is read into the control unit 25. And step 8
Proceeding to step 75, the bad road judgment is canceled. This is done, for example, by resetting the rough road solenoid in the memory area of the control unit 25, which is set when the vehicle is traveling on a rough road. Thereafter, when 2 seconds are counted by the 2 second timer, it is determined in step 512- that "ygsJ" and the process proceeds to step 816. In this step F316, the 2 second timer is reset. Then, in step 517 (C
The vehicle height sensor detected in step S13, ? From 2F (, ?2R), it is determined whether the HH code, that is, the vehicle height higher than the high vehicle height level has been output two or more times. If the determination in step 877 is "YES", the process advances to step S18. In step 818, the vehicle height sensor 2, z detected in step 813 is
From F(zzR), it is determined whether the LL code, that is, the vehicle height lower than the low vehicle height level has been output twice or more. If it is determined as YES in step 818, the process advances to step F319 and a rough road determination is established. This is done by setting the rough road flag. On the other hand, in step 877 or SZ, 9 “NO
”, the process proceeds to step 82 (11) where the acceleration (
G) It is determined whether the output signal of the sensor 28 has been turned on two or more times. In other words, the output of the acceleration (G) sensor 28 is 2
It is determined whether the state of low acceleration and high acceleration has passed two or more times within a second.

If l'-ygsj is determined in this step F320, the process proceeds to step E321, where it is determined whether or not the output signal of the acceleration (G) sensor 28 was turned on two or more times during the previous two seconds.This step S21 In "Yg'
If it is determined that sJ, the process proceeds to step S19, where the rough road determination is established, and if the determination is "NO" in step S2I, the process proceeds to step S15, where the rough road determination is canceled. Vehicle height sensor like this: tzF (zzR)
Alternatively, a rough road judgment is made based on the output signal of the acceleration (G) sensor 28.

Next, the target vehicle height determination carried out in step S3 in FIG. 3 will be explained in detail with reference to FIG. First, in step F331, it is determined whether the rough road determination is established. If it is determined as YESJ in this step S31, the process proceeds to step S32 and the target vehicle height is set to high (HI).
GH). On the other hand, if it is determined as NOJ in steps S and 9Z, the process proceeds to step 833, where it is determined whether or not the judgment has been canceled after the rough road judgment has been established.

This step S3,? If it is determined that i'-ygsJ in step B54jC, it is determined whether 12 seconds have elapsed since the rough road determination was canceled. If f-NOJ is determined in step S34, the process proceeds to step B32. In other words, even if the rough road judgment is canceled, the target vehicle height is set to high (HIO2()) for 12 seconds.
If it is determined that, step S, ? Proceeding to step 5, it is determined whether the target vehicle height is set to normal (medium).

This step S? If the determination in step S'36 is "NOj", the process proceeds to step 836, where it is determined whether the vehicle speed detected by the vehicle speed sensor 27 is less than or equal to 70 h.If the determination is "No" in step S'36, the process proceeds to step S
Proceeding to step 37, the target vehicle height is set to "low".

On the other hand, if it is determined in step S35 that [yEsJ], the process proceeds to step B58VtC, where it is determined whether the vehicle speed detected by the vehicle speed sensor 2.7 is 90 Km/h or more. If it is determined as YESj in this step 838, step S, ? 9, it is determined whether the vehicle speed has been 90 Kih or higher for 10 seconds or not. 3. Step S? 9, if it is determined that the
is set.

In other words, even if the target vehicle height is normal, when the vehicle speed reaches 90 @/h or more for 10 seconds, the target vehicle height is set to low and driving stability is ensured. On the other hand, step 838
If the determination is "No" in step B40, the target vehicle height is set to normal (middle). In this way, even after the rough road judgment is canceled, the target vehicle height remains high (
mIoa).

As detailed above, according to the present invention, it is possible to
In a vehicle height control device that can perform vehicle height control in three stages (low), the vehicle height sensor or acceleration sensor determines that the vehicle is driving on a rough road and the target vehicle height is set to high, and then the rough road determination is canceled. Since the target vehicle height is also set high for the set time, it is possible to provide an electronically controlled suspension system that can prevent an increase in consumption of the batch IJ source.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a car equipped with this installation, Fig. 2 is an overall configuration diagram of the installation cost, and Figs. 3 to 5 are flowcharts for explaining the operation of one embodiment. . DESCRIPTION OF SYMBOLS 11... Compressor, 25... Control unit, 27... Vehicle speed sensor, 31... Mode selection switch. HikiR 1 agent patent attorney Suzue Takehiko 3rd ji! i
i Figure 4

Claims (1)

[Claims] A hydraulic suspension unit that is interposed between a wheel side member and a vehicle body side member of a vehicle and has a vehicle height adjustment fluid chamber, a vehicle height sensor that detects vehicle height, and an acceleration sensor that detects acceleration acting on the vehicle body. The sensor compares the vehicle height detection signal obtained by the vehicle height sensor with a set target vehicle height, controls the fluid to change the vehicle height to the target vehicle height, and also controls high, medium, and low. A control device capable of setting three target vehicle heights, a rough road determining means for determining whether the road is rough based on the vehicle height sensor or the acceleration sensor, and a rough road determining means determining that the road is rough. an electronically controlled suspension device comprising: a target vehicle height setting means for setting a target vehicle height high when the vehicle is on a bad road; and continuing to set the target vehicle height high for a set time after the rough road determination is canceled.