JPS60255519A - Electronic-controlled suspension apparatus - Google Patents

Abstract

PURPOSE:To prevent the increase of the consumption of battery power source by releasing the judgement for bad road when the judgement for good road continues for a set time or more after the bad road traveling is judged. CONSTITUTION:A mode selecting switch 31 performs switching between the auto mode in which car-height is controlled automatically to normal car-height or low car-height and the high mode in which car-height is controlled to high car-height. The judgement for bad road is performed according to each output signal of car- height sensors 22F and 22R or an acceleration sensor 28. It is judged that the judgement of bad road for each 2sec is performed six times in succession, in other words the judgement of bad road is performed for 12sec, and when the judgement is YES, the judgement for bad road is released. 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 solenoid valve 14, front solenoid valve 15, and a connection port 17 communicating to the pipings 16 and the communication passages which are connected to the above-described devices.

Description

[Detailed Description of the Invention] The present invention provides a vehicle height control lid that can control vehicle height in three stages: "high", "medium", and "low", and detects when driving on a rough road using a vehicle height sensor or an acceleration sensor. The present invention relates to an electronically controlled suspension system in which the bad road judgment is canceled when the road continues to be good for a set time after being judged.

Conventionally, when driving on rough roads, the vehicle height is raised to increase the minimum ground clearance of the vehicle, reducing contact between the road surface and the storage body, improving traversability on rough roads and reducing damage to the vehicle body. A vehicle height control device for this purpose 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 judged to be good. The vehicle height adjustment was repeated alternately, and the vehicle height could not be adjusted smoothly at high vehicle heights, which was dangerous and resulted in an increase in air consumption, an increase in the frequency of compressor operation, and an increase in battery power consumption. However, if a vehicle is equipped with a lamp that indicates that the vehicle height is being adjusted, there is a problem in that the lamp repeatedly turns on and off, reducing the reliability of the system.

This invention was made in view of the above points.

The purpose of this is to use a vehicle height control device that can control the vehicle height in three levels: high, medium, and low J. The object of the present invention is to provide an electronically controlled suspension device that can prevent an increase in battery power consumption by canceling the determination when the road continues to be good for a set time or more.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a car equipped with the present device.

As shown in Fig. 1, a front air suspension unit FB (181°psz) is interposed between the left and right ends of the front wheel FA side axle and the vehicle body B side member, and the rear wheel BA side axle A rear air suspension unit R8 (R8z, R8z) is interposed between both left and right ends of the vehicle and the vehicle body B side member.

These air suspension units F81°FS+,
Since the R81 and R8z each have almost the same structure, the air suspension unit will be designated by the symbol S as shown in Figure 2, unless the front and rear suspension units are explained separately. In addition, only the parts necessary for vehicle height control will be illustrated and explained.

In other words, these air suspension units S are
The strut-type damping force switching two-gate shock absorber 1 is incorporated.
The cylinder is equipped with a cylinder attached to the A side or the rear wheel BA side, and a piston that is slidably inserted into the cylinder. , 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 splash chamber 3 that also serves as a fluid chamber for adjusting vehicle height is disposed coaxially with the piston rod 2 in the upper part of the shock absorber 1. Since the section 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 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 splash chambers 3 and 5 are connected to an on-off valve 10 that constitutes a spring constant switching mechanism via a communication passage 9 formed in a control rod 8 that is rotatably inserted into the piston rod 2. It has been mediated.

This on-off valve 10 includes a first valve part ZOa that cuts off communication between the auxiliary air splash chamber 5 and the communication passage 9, and a second valve part that cuts off communication between the main air splash chamber 3 and the communication passage 9. 10b
It is composed of:

Therefore, when the on-off valve 10 is in the open mode, the main air spring chamber 3 and the auxiliary air spring chamber 6 are brought into communication, so that 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 are brought into a closed state pressure, and the spring constant can be increased (hardened).

In other words, by rotating the control rod 8, the on-off valve 10 can be opened and closed, and the spring chamber capacity can be changed by this opening and closing.

This change in spring chamber capacity also causes suspension at the lower end of the control rod 8.

A control valve 8a is provided that can change the orifice area of the piston 1a of the shock absorber 1. This control valve 8a is an on-off valve I by a control rod 8.
When the Q is in the open mode, the orifice area of the LC histone 1a is increased to decrease the damping force, and when the on-off valve 10 is in the closed mode, the orifice area of the piston 1a is decreased to increase the damping force. There is.

Thus, the vehicle height adjustment of the automobile is carried out by the configuration shown in FIG. In other words, the compressed air for vehicle height adjustment is
As shown in the figure, from a compressor 11 as a compressed air generating device to a dryer 12, a joint 13. The rear solenoid pulp 14, the front solenoid valve 15, and the upper part are connected to each suspension unit s through a pipe 16 that connects these, and a connection port 17 that communicates with a communication passage 9 in a partially pipe-shaped control rod. It is now being supplied.

The compressor 11 compresses the atmospheric air sent from the air cleaner 18 and supplies it to the dryer 12. The compressed air dried by silica gel, etc. As shown, it is supplied to the suspension unit S. Also, when the compressed air is exhausted from the suspension unit s, the second
Exhaust as indicated by each dashed arrow in the figure.

Compressed air is released to the atmosphere via the lenoid valve 19.

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 8 via an air supply solenoid valve 2e.

Further, as shown in FIG. 2, a vehicle height sensor 22 is provided, and this vehicle height sensor 22 is attached to the lower arm 2s 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 2 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.
2R, and a front vehicle height detection signal and a rear torsion height detection signal are supplied from these vehicle height sensors 22F and 22R to a control unit 25 of the vehicle height adjustment control section.

Each of the sensors 22F and 22B in the vehicle height sensor 22 has a Hall IC element and a magnet, one of which is attached to the wheel FA side and the other to the main body B side, and the distance from the normal vehicle height level and the low or high vehicle height level. It is designed to detect each. Hiko, please use another type of vehicle height sensor, such as a phototransistor! ? I don't mind anything.

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 switch-type vehicle speed sensor is used, and the speed is electronic.

For meters, open collector output type sensors using transistors are used.

Further, an acceleration sensor 28 is installed as a vehicle attitude sensor for detecting changes in the attitude of the vehicle. becomes 1
For example, when the acceleration is not equal to 0, the light from the light emitting diode is blocked by the shielding plate and does not reach the photodiode due to the hanging condition.
The structure is such that it can detect the absence of acceleration.

When acceleration acts in the front and back, left and right directions, and up and down, the acceleration state of the vehicle body is detected by the tilting or movement of the weight.

Reference numeral 32 is a steering sensor that detects the rotational speed of the steering wheel S3, that is, the steering speed.

34 is an accelerator sensor that detects the steering speed of the accelerator pedal of the engine (not shown); 35 is a reserve tank 2;
A pneumatic drive mechanism is connected to the control rod 8 through three three-way switching valves, respectively, and rotates the control rod 8.
The direction switching valve 36 can select either a position where the pneumatic drive mechanism 35 and the reserve tank 2o are communicated or a position where the pneumatic drive mechanism 35 is communicated with the atmosphere according to a signal from the control unit 25. This function has the function of rotating the control rod 3 in the opposite direction to a predetermined position to shift from the soft state to the eight-position state. Note that it is also possible to use an air cylinder type drive mechanism instead of the solenoid type drive mechanism 2o. Also 1 code L
P indicates the boundary between the engine room 1llLF (to the left) and the passenger compartment (between the broken lines LP and LR), and LR indicates the boundary between the passenger compartment and the trunk room (to the right of the broken line LR). Also, the code 3o is.

A hump stopper is shown to prevent damage to the wall surface of the main air spring chamber 3 due to the relative rise of the cylinder of the eye absorber 1 on rough roads at equal pressure. Reference numeral 31 is a mode selection switch serving as a high vehicle height selection switch. By the way, this mode selection switch s1
It is possible to switch between auto mode, which automatically controls the vehicle height to normal vehicle height or low vehicle height, and high mode, which automatically controls vehicle height to 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, an auto mode is set as an initial setting in which vehicle height adjustment is automatically set to a "medium" or "low" vehicle height. Then, the normal and "medium" vehicle heights are set as the target vehicle heights. Next, in step 82, it is determined whether or not the road surface on which the vehicle is traveling is a rough road (details of which will be described later with reference to FIG. 4). Then, in step s3, a target vehicle height is determined, the details of which will be described later, using FIG. 5, and it is determined to what extent the multi-purpose target vehicle height should be set. Then, proceed to step s4 and set the vehicle height sensor 2.
A vehicle height signal is read into the control unit 25 from 2F (zzR). Then, in step 85,
It is determined whether the vehicle height detected by the vehicle height sensor 22F (22R) is equal to the target vehicle height set in step S3.

If NOJ is determined in step s5, the process proceeds to step S6, where 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 vehicle height, the vehicle height is raised by supplying air to the main air spring chamber 3 of each 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, the process returns to step S2, and when the vehicle height becomes equal to the target vehicle height in step S5, the process proceeds to step S7, where 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. First, in step 810, the vehicle speed is 40 km/h.
If it is determined that it is [Y) 3SJ, then in step 811 the time of the 2 second timer for counting 2 seconds is read into the control unit 25.

Then, in step 812, a 2 second timer 92
It is determined whether the second has been counted. This step 812
If the determination is "NO" in step S13, the output signal of the vehicle height sensor z;tF(z;tR) is read by the control unit 25Tlc, and the process proceeds to step S13.
14, the output signal of the acceleration (G) sensor 28 is read into the control unit 25. Thereafter, when 2 seconds are counted by the 2-second timer, it is determined in step 812 that the result is 1'-YB8J, and the process proceeds to step 816.

In step 816, the two second timer is reset. Then, proceeding to step 817K, the vehicle height sensor ztF(z
zR), 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 rYR8J is determined in this step BIT, the process proceeds to step 81B. In step 81g, the vehicle height sensor 22F (22R) detected in step 81B is
), it is determined whether a vehicle height lower than the LL code and the lower vehicle height level has been output two or more times.

If it is determined as [Y E 8J in step 81g, the process proceeds to step 819 and the rough road determination is established. This is done by setting the rough road flag. On the other hand, in step 817. 1) Ruiha 81
If l'-NOJ is determined in B, step 82
0, it is determined whether the output signal of the acceleration (G) sensor 28 has been turned on two or more times. Tsuma υ, acceleration 1 (G)
It is determined whether the output of the sensor 28 has passed through a low acceleration state and a high acceleration state two or more times within two seconds. In this step 820, if it is determined as YB8J, step 8
21 K- It is determined whether or not the output signal of the acceleration (G) sensor 28 has been turned on two or more times during the previous two seconds. If the road is determined to be YE8J at step 821 Km, the process proceeds to step 81s and the rough road judgment is established. If the road is determined to be l'-N OJ at step 820, the process proceeds to step 82H and the road is determined to be bad road every 2 seconds. It is determined whether the road judgment has not been made 6 times in a row.Tsumashi, 1
It is determined whether or not there is a bad road judgment for 2 seconds, and l'-Y Ii
18'', the process advances to step S23 and the rough road determination is canceled. In this way, the vehicle height sensor 22F (2
2B> or the output signal of the acceleration Q[G) sensor 28 to determine whether the road is rough. Note that if it is determined as NOJ in step 81o, the process proceeds to step 82g.Next, referring to FIG. 5, the target vehicle height determination performed in step S3 in FIG. 3 will be explained in detail.First, In step S31, it is determined whether or not the rough road judgment is established.In step S31, 1"Y
If it is determined to be E8J, the process proceeds to step 832, where the target vehicle height is set to high (HIGH). On the other hand, if it is determined as f-, NOJ in step 8sz, the process proceeds to step S33, where it is determined whether or not the mode selection switch 5xVc has selected the automatic (AUTO) mode. In this step 8s3, rY F! If it is determined that the vehicle height is SJ, the process proceeds to step 834, where it is determined whether the target vehicle height is set to normal (middle). In this step 834, if it is determined as NOJ, step 8s
Proceed to step 5 and the vehicle speed detected by the vehicle speed sensor 27 is 70Rm.
It is determined whether or not it is less than /h. If the determination in step St5 is "NO", the process proceeds to step 836, where the target vehicle height is set to "low".

On the other hand, if the determination in step 834 is YES, the process proceeds to step S37, where it is determined whether the vehicle speed detected by the vehicle speed sensor 27 is greater than or equal to 90+n/h.

In this step 837.

[If it is determined as YESJ, it is determined in step 8gB whether or not the vehicle speed has been 90 Rm/h or higher for 10 seconds. In this step 838, “YE8J
If it is determined that this is the case, the process proceeds to step 836 and the target vehicle height is set to low.

Even if the target vehicle height is normal, if the vehicle speed exceeds 90 km/h for 10 seconds, the target vehicle height is set to low to ensure driving stability. On the other hand, step 8i7 above
If the determination is "NO" in step 839, the target vehicle height is set to normal (medium).

By the way, if it is determined in step 8sg that the vehicle height selection mode is set to "NO", step 84 is executed.
0, it is determined whether the target vehicle height is set to a high level. If the determination in step 840 is YES, the process proceeds to step S41, where it is determined whether the vehicle speed is 70 Rm/h or more. If the determination in step 841 is NO, the process proceeds to step 8d2. On the other hand, in step 841, 1
If it is determined as '-YE8J, the process proceeds to step 842, where it is determined whether 10 seconds have elapsed since the vehicle speed became 70 Rm/h or more. In this step 842, “NO
If it is determined to be J, the process proceeds to step 8st, and if it is determined to be YBsJ in step 842, the process proceeds to step 8:d9K.

On the other hand, if the determination in step 840 is "NO", the process proceeds to step 843 and the target vehicle height is set to normal (
Medium) It is determined whether the level is high or not. If it is determined in this step 843 that jY B 8j, the step 84 is performed.
Proceeding to step 4, it is determined whether the vehicle speed is 50 h/h or less.

If l'-Y Ft 8J is determined in step 844, the process proceeds to step S32. On the other hand, if the determination in steps 843 and 84-4 is "NO", the process proceeds to step 834.

In this way, when the rough road judgment is established, the target vehicle height is set to high.

As detailed above, according to this invention, "high" and "medium"
In a vehicle height control device that can perform three-level JCM height control (low), after the vehicle height sensor or acceleration sensor determines that the vehicle is driving on a rough road, the rough road continues to be determined to be a good road for a set period of time. Since the suspension is released when the IF is released, it is possible to provide an electronically controlled suspension device that can prevent an increase in battery power consumption.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram and chart of an automobile equipped with this device. 11...Compressor 251/Control unit 27...Vehicle speed sensor 3...Mode selection switch Applicant's representative Patent attorney Takehiko Suzue Continued from page 1 0 Author: Tadashi Sugawara @ Inventor: Shigeo Kariya @Inventor Hiroshima - 1 Nakashinkiri, Hashime-cho, Okazaki-shi Mitsubishi Motors Corporation Passenger Vehicle Technology Center 1 Nakashinkiri, Hashime-cho, Okazaki City Mitsubishi Motors Corporation Passenger Vehicle Technology Center Aza Naka, Hashime-cho, Okazaki City Shinkiri 1 Mitsubishi Motors Corporation Passenger Vehicle Technology Center

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. The vehicle determines whether the vehicle is traveling on a rough road based on a control device that can set three target vehicle heights and the vehicle height sensor or acceleration sensor, and cancels the rough road determination if the rough road determination exceeds a set time. An electronically controlled suspension device comprising: a rough road determining means; and a target vehicle height setting means for setting a target vehicle height to a high level when the rough road determining means determines that the road is rough.