JP6842360B2 - Vehicle height control system - Google Patents

Description

The present invention relates to a vehicle height control system that controls the vehicle height of wheels.

In the vehicle height control system described in Patent Document 1, when the vehicle height is lower than the target vehicle height, the vehicle height is increased by supplying air to the air cylinder, and the vehicle height is relative to the target vehicle height. When it is too high, the vehicle height is lowered by discharging air from the air cylinder.

Japanese Unexamined Patent Publication No. 3-70615

An object of the present invention is to reduce the inclination of the vehicle body of a stopped vehicle in the left-right direction.

Means and effects to solve problems

In the vehicle height control system according to the present invention, the lower vehicle height of the left vehicle height and the right vehicle height is raised while the vehicle is stopped, and the height is substantially the same as the higher vehicle height. As a result, the inclination of the vehicle body of the stopped vehicle in the left-right direction can be reduced.

It is a circuit diagram which shows the vehicle height control system which concerns on Example 1 of this invention. It is a conceptual diagram which shows the periphery of the vehicle height control ECU of the vehicle height control system. It is a figure which shows the state which up control is performed in the said vehicle height control system. It is a figure which shows the state which down control is performed in the said vehicle height control system. It is a flowchart which shows the start condition establishment determination program stored in the storage part of the vehicle height control ECU. It is a flowchart which shows the appearance improvement control program stored in the storage part of the vehicle height control ECU. It is a flowchart showing a part of the appearance improvement control program (S23, 24, 27, 28). It is a figure which conceptually shows the state of the vehicle when the above-mentioned appearance improvement control program is executed. (A) Change in vehicle speed, (b) Ignition switch ON / OFF status, (c) Door open / close status, (d) Door open / close flag status, (e) Door It is a figure which shows the state of locked and unlocked, and (f) the change of the vehicle height. It is a flowchart which shows the appearance improvement control program different from the appearance improvement control program.

Embodiment of the invention

Hereinafter, a vehicle height control system according to an embodiment of the present invention will be described in detail with reference to the drawings. In this vehicle height control system, air as a pressure medium is used.

In the vehicle height control system according to the present embodiment, as shown in FIG. 1, a wheel side member (for example, a suspension arm that supports the wheels, etc.) corresponds to each of the front, rear, left, and right wheels provided in the vehicle. A suspension spring (not shown) and an air cylinder 2FL, FR as a vehicle height control actuator are provided between the vehicle body side member (for example, a member that can move integrally with the vehicle body 120 shown in FIG. 8). , RL, RR and the shock absorbers 4FL, FR, RL, RR are provided in parallel with each other. The shock absorbers 4FL, FR, RL, and RR include an absorber main body provided on the wheel side member and an absorber piston provided on the vehicle body side member, respectively.
Hereinafter, in the present specification, when it is necessary to distinguish the air cylinder 2, the shock absorber 4, etc. by the position of the wheel, the reference numerals FL, FR, RL, and RR indicating the position of the wheel are added to distinguish the air cylinder 2, the shock absorber 4, and the like. , When it is not necessary to distinguish by the position of the wheel, when expressing a generic term, etc., the symbols FL, FR, RL, RR, etc. indicating the position of the wheel are omitted.

The air cylinders 2 are provided on the cylinder body 10 provided on the vehicle body side member, the diaphragm 12 fixed to the cylinder body 10, and the absorber bodies of the diaphragm 12 and the shock absorber 2 so as to be relatively immovable in the vertical direction. An air piston 14 is included, and the inside thereof is an air chamber 19 as a pressure medium chamber. The air supply / discharge in the air chamber 19 causes the air piston 14 to move relative to the cylinder body 10 in the vertical direction, whereby the absorber body and the absorber piston are moved relative to the cylinder body 10 in the vertical direction. , The vehicle height, which is the distance between the wheel side member and the vehicle body side member, can be changed.

An air supply / discharge device 24 as a pressure medium fluid supply / discharge device is connected to the air chamber 19 of the air cylinder 2 via an individual passage 20 and a common passage 22, respectively. A vehicle height control valve 26 is provided in each of the individual passages 20. The vehicle height control valve 26 is a normally closed solenoid valve that can be opened and closed by turning the solenoid on and off. The vehicle height control valve 26 allows bidirectional air flow in the open state and blocks the air flow from the air chamber 19 to the common passage 22 in the closed state, but the pressure in the common passage 22 is the air chamber. When the pressure is higher than the set pressure of 19, the air flow from the common passage 22 to the air chamber 19 is allowed.

The air supply / exhaust device 24 includes a compressor device 30, an exhaust valve 32 which is a normally closed solenoid valve, a tank 34, a switching device 36, an intake valve 44, a relief valve 46, and the like.
The compressor device 30 includes a compressor 40 and an electric motor 42 for driving the compressor 40, and the compressor 40 is operated by driving the electric motor 42. When the discharge pressure of the compressor 40 becomes high, air is discharged to the atmosphere through the relief valve 46.
The tank 34 accommodates air in a pressurized state, and as the amount of contained air increases, the tank pressure, which is the pressure of the contained air, increases.

The switching device 36 is provided between the common passage 22, the tank 34, and the compressor device 30, and switches the direction in which air flows between them. As shown in FIG. 1, the common passage 22 and the tank passage 48 to which the tank 34 is connected are connected by the first passage 50 and the second passage 52 provided in parallel with each other, and the first passage 50 is connected to the first passage 50. Two circuit valves 61 and 62 are provided in series, and two circuit valves 63 and 64 are provided in series in the second passage 52. Further, the portion between the two circuit valves 61 and 62 of the first passage 50 and the intake side portion 40a of the compressor 40 are connected by the third passage 65, and the discharge side portion of the compressor 40 is connected by the fourth passage 66. The portion between 40b and the two circuit valves 63 and 64 of the second passage 52 is connected.

The circuit valves 61 to 64 are normally closed solenoid valves, and can be switched between an open state and a closed state by turning the solenoid on and off. Allows bidirectional air flow in the open state and blocks air flow from one side to the other in the closed state, but the pressure on the other side is higher than the set pressure on the other side. Then, the flow of air from the other side to one side is allowed.
The circuit valves 61 and 63 prevent the outflow of air from the tank 34 in the closed state, and the circuit valves 62 prevent the outflow of air from the common passage 22 in the closed state. 64 blocks the supply of air to the common passage 22 in the closed state.

An intake valve 44 is provided between the connection portion 65s of the third passage 65 and the atmosphere. The intake valve 44 is a check valve that closes when the air pressure of the connecting portion 65s is equal to or higher than the atmospheric pressure and opens when the pressure of the air at the connecting portion 65s is lower than the atmospheric pressure. When the pressure of the air in the connection portion 65s becomes lower than the atmospheric pressure due to the operation of the compressor 40, the air is sucked from the atmosphere through the filter 43 and the intake valve 44.
An exhaust valve 32 is connected to the connection portion 66s of the fourth passage 66. The exhaust valve 32 is a normally closed electromagnetic valve, and in the open state, air is allowed to be discharged from the fourth passage 66 to the atmosphere, and in the closed state, air is prevented from being discharged from the fourth passage 66 to the atmosphere. However, when the pressure of the air in the fourth passage 66 becomes lower than the atmospheric pressure by the set pressure or more, the supply of air from the atmosphere to the fourth passage 66 is permitted.
Further, a dryer 70 and a flow suppressing mechanism 72 are provided in series in a portion of the fourth passage 66 on the second passage side of the connecting portion 66s. The flow suppression mechanism 72 includes a differential pressure valve 72v and a throttle 72s provided in parallel with each other. The differential pressure valve 72v blocks the flow of air from the second passage side to the compressor side, and when the pressure on the compressor side becomes higher than the set pressure than the pressure on the second passage side, the air from the compressor 40 to the second passage 52 Allow the flow.

In this embodiment, the vehicle height control system is controlled by a vehicle height control ECU 80 mainly composed of a computer. The vehicle height control ECU 80 is capable of communicating with the ECU and the like via the CAN (Controller Area Network) 82. As shown in FIG. 2, the vehicle height control ECU 80 includes an execution unit 80c, a storage unit 80m, an input / output unit 80i, a timer 80t, and the like, and the input / output unit 80i includes a vehicle height changeover switch 88, a tank pressure sensor 90, and the like. The cylinder pressure sensor 91, the vehicle height sensor 93, the boarding / alighting related motion detection device 95, etc. are connected, and the communication device 96, the ignition switch 98, the vehicle speed sensor 99, etc. are connected via the CAN 82. Further, the electric motor 42 is connected via the drive circuit 100, and the exhaust valve 32, the vehicle height control valve 26, and the circuit valves 61 to 64 are connected.

The vehicle height changeover switch 88 is operated by the driver, and is operated when instructing the vehicle height to be changed to any one of L (Low), N (Normal), and H (High). .. The tank pressure sensor 90 detects the tank pressure, and the cylinder pressure sensor 91 is provided in the common passage 22, and when the vehicle height control valve 26 is opened, it corresponds to the vehicle height control valve 26 in the opening (the tank pressure sensor 90 is provided). The cylinder pressure, which is the pressure of the air chamber 19 of the cylinder 2 (corresponding to the wheel), is detected. Further, the passage pressure, which is the pressure of the air in the common passage 22, is detected in the closed state of all the vehicle height control valves 26. The vehicle height sensor 93 is provided corresponding to each of the front, rear, left, and right wheels, and detects the vehicle height, which is the distance of the vehicle body side member from the wheel side member. The boarding / alighting-related motion detection device 95 detects the presence / absence of motion related to boarding / alighting, and is provided corresponding to each of a plurality of doors provided in the vehicle, and is a door open / close sensor (door open / close sensor) for detecting the opening / closing of the door. It may include a vehicle sensor) 102, a door lock sensor 103 for detecting the lock and unlock of each of a plurality of doors, and the like. The intention of getting on, getting off, and starting is estimated based on the presence or absence of door opening / closing, door locking, and unlocking operations. The communication device 96 communicates with the portable device 104 owned by the driver or the like within a predetermined communicable area, and the door may be locked or unlocked by the communication. .. The ignition switch 98 is the main switch of the vehicle. The vehicle speed sensor 99 detects the traveling speed of the vehicle.
Further, the vehicle height control system and the like in this embodiment can be operated by the electric power of the battery 110. The voltage of the battery 110 is detected by the voltage monitor 112, and the voltage monitor 112 is connected to the vehicle height control ECU 80.

In the vehicle height control system according to the present embodiment, when up control, which is vehicle height control for increasing the vehicle height, is performed, the circuit valves 61 to 64 are opened and controlled as shown in FIG. The vehicle height control valve 26RL corresponding to the target wheel (in FIG. 3, the case where the left rear wheel is the control target wheel; the same applies to FIG. 4) is opened. The air stored in the tank 34 is supplied to the air chamber 19RL of the air cylinder 2RL of the control target wheel. As a result, the vehicle height HRL for the controlled wheel becomes high.

When down control, which is vehicle height control for lowering the vehicle height, is performed, as shown in FIG. 4, the compressor 40 is operated by driving the electric motor 42, the circuit valves 61 and 64 are closed, and the circuit valves 62. , 63 are opened, and the vehicle height control valve 26RL corresponding to the controlled wheel is opened. Air is discharged from the air chamber 19RL of the air cylinder 2RL of the control target wheel and supplied to the tank 34. As a result, the vehicle height HRL for the controlled wheel becomes low.

Further, in the present embodiment, the appearance improvement control is performed when a predetermined start condition is satisfied in the stopped state of the vehicle. As a result, the inclination of the vehicle body 120 in the left-right direction is reduced, and the appearance is improved.

For example, when the ignition switch 98 is ON, the vehicle height is controlled at a predetermined timing, so that the inclination of the vehicle body 120 (see FIG. 8) in the left-right direction is usually small.
However, the load applied to each of the front, rear, left, and right wheels of the vehicle is not always the same, and the air pressure of the air chamber 19 of the air cylinder 2 corresponding to each of the wheels is not always the same. Therefore, when the ignition switch 98 is turned off and the occupant disembarks, the vehicle height of the wheel corresponding to the air cylinder 2 having a high air pressure before disembarking corresponds to the air cylinder 2 having a low air pressure. It may be higher than the vehicle height of the wheels, and the vehicle body 120 may tilt in the left-right direction.

Further, as described above, even when the vehicle height is controlled at a predetermined timing, the vehicle height on the right side, which is the vehicle height on the right side wheel, on at least one of the front wheel side and the rear wheel side ( Hereinafter, the vehicle height for the right front wheel or the vehicle height for the right rear wheel may be referred to as the right vehicle height) and the vehicle height for the left wheel (hereinafter, the vehicle height for the left front wheel). , Or the vehicle height for the left rear wheel may be referred to as the left vehicle height). Therefore, even if the change in vehicle height when the occupant gets off is small, the vehicle height on the right side and the vehicle height on the left side may be different, and the vehicle body 120 may be tilted in the left-right direction.

On the other hand, when (i) the vehicle is stopped, (ii) the ignition switch 98 is OFF, and (iii) the door is switched from the unlocked state to the locked state after the door is opened and closed. It is presumed that there are no occupants in the passenger compartment because a person got off the vehicle. Also, since it is unlikely that a person will get on the vehicle immediately, the load applied to each wheel is kept almost constant, in other words, the inclination of the vehicle body 120 due to the change in the load applied to each wheel is It can be inferred that the condition is unlikely to occur.
From the above, in this embodiment, the above conditions (i) the vehicle is in a stopped state, (ii) the ignition switch 98 is OFF, and (iii) the door is opened and closed, and then the door is opened. When it is established that the unlocked state is switched to the locked state, it is determined that the start condition of the appearance improvement control is satisfied, and the appearance improvement control is performed.

The appearance improvement control is a vehicle height control for improving the appearance of the stopped vehicle, and in the present embodiment, one-sided up control is performed as the appearance improvement control. One-sided up control is a control in which the lower vehicle height of the right side vehicle height and the left side vehicle height is increased to be approximately the same as the higher vehicle height on each of the front wheel side and the rear wheel side. ..

On the other hand, in order to make the right-side vehicle height and the left-side vehicle height almost the same, one-sided up control is required to raise the lower vehicle height of the right-side vehicle height and the left-side vehicle height to match the higher vehicle height. One-sided down control is conceivable, in which the higher vehicle height is lowered to match the lower vehicle height. When these are compared, the possibility that the vehicle body 120 hits an object (for example, a branch, a roof, etc.) existing above the vehicle body 120 by one-sided up control is an object existing below (for example, a branch, a roof, etc.) by one-sided down control. It is presumed that it is less likely to hit the flap plate of the parking lot. Therefore, in this embodiment, one-sided up control is performed.

The appearance improvement control program represented by the flowchart of FIG. 6 is executed when the start condition is satisfied and the start condition establishment flag is turned ON. The determination as to whether or not the start condition is satisfied is performed by executing the start condition establishment determination routine represented by the flowchart of FIG.
Whether or not the vehicle speed Vs detected by the vehicle speed sensor 99 in step 1 (hereinafter abbreviated as S1; the same applies to the other steps) is smaller than the set speed V0 at which the vehicle can be considered to be in a stopped state. It is judged. If the determination is YES, it is determined in S2 whether or not the door open / close flag is ON. When the door open / close flag is OFF, in S3, the door open / close sensor 102 determines whether or not at least one of the plurality of doors provided in the vehicle has been opened or closed. If the door is not opened or closed, the determination in S3 becomes NO, and S1 to 3 are repeatedly executed. If at least one door is opened or closed in the meantime, the door open / close flag is turned ON in S4.

Then, in S5, it is determined whether or not the ignition switch 98 is OFF, and in S6, it is determined whether or not all the plurality of doors have been switched from the unlocked state to the door locked state. When the ignition switch 98 is OFF and all of the plurality of doors are switched from the unlocked state to the locked state, the judgment of S6 becomes YES, the start condition establishment flag is turned ON in S7, and the door open / close flag is OFF. It is said that. When the vehicle speed Vs is equal to or higher than the set speed V0 and the determination in S1 is NO, the door open / close flag and the start condition establishment flag are turned off in S8.

When the start condition establishment flag is turned ON, the appearance improvement control represented by the flowchart of FIG. 6 is performed.
In S20, the vehicle height sensor 93 detects the vehicle height Hij (i = F, R, j = R, L) for each of the front, rear, left, and right wheels. Then, in S21 and 22, on the front wheel side, the right vehicle height (vehicle height for the right front wheel) HFR and the left vehicle height (vehicle height for the left front wheel) HFL are compared. When the left vehicle height HFL is lower than the right vehicle height HFR, air is not supplied to the air cylinder 2FR of the right front wheel as the right vehicle height control actuator in S23, and the air of the left front wheel as the left vehicle height control actuator is not supplied. Air is supplied to the cylinder 2FL. As a result, the vehicle height HFL of the left front wheel is set to be substantially the same height as the vehicle height HFL of the right front wheel (HFL≈HFR), and one-sided up control is performed. Specifically, as shown in the flowchart of FIG. 7, in S51, the circuit valves 61 to 64 are opened, the vehicle height control valves 26FR, RL, and RR are closed, and the vehicle height control valve 26FL is opened. Will be done. In S52, the vehicle height HFL of the left front wheel is detected, and in S53, it is determined whether or not the vehicle height HFL of the left front wheel is substantially the same as the vehicle height HFR of the right front wheel. While the determination of S53 is NO, S52 and 53 are repeatedly executed. Then, when the vehicle height HFL of the left front wheel becomes almost the same as the vehicle height HFR of the right front wheel and the determination of S53 becomes YES, the circuit valves 61 to 64 are closed and the vehicle height control valve 26FL is closed in S54. It will be done. This routine is similarly executed in S24, 27, and 28 below. In S23, the subscript i is F (front wheel side), a is L (left side), and b is R (right side).

On the other hand, when the right vehicle height HFR is lower than the left vehicle height HFL, air is not supplied to the air cylinder 2FL of the left front wheel and air is supplied to the air cylinder 2FR of the right front wheel in S24. As a result, the vehicle height HFR of the right front wheel is raised to be substantially the same height as the vehicle height HFL of the left front wheel (HFR≈HFL), and one-sided up control is performed. In S24, the subscript i is F, a is R, and b is L. Further, when the right-side vehicle height HFR and the left-side vehicle height HFL are substantially the same (HRR≈HRL), the determination of S21 and 22 becomes NO, and one-sided up control is not performed.

In S25 to 28, the same execution is performed on the rear wheel side. In S25 and 26, the right vehicle height (vehicle height for the right rear wheel) HRR and the left vehicle height (vehicle height for the left rear wheel) HRL are compared. When the left vehicle height HRL is lower than the right vehicle height HRR, one-sided up control is performed in S27. Air is supplied to the air cylinder 2RL of the left rear wheel as the left vehicle height control actuator, which raises the vehicle height HRL of the left rear wheel and makes it almost the same height as the vehicle height HRL of the right rear wheel (HRL). ≒ HRR). When the right-side vehicle height HRR is lower than the left-side vehicle height HRL, one-sided up control is performed in S28. By supplying air to the air cylinder 2RR of the right rear wheel as the right vehicle height control actuator, the right vehicle height HRR is raised to be substantially the same height as the left vehicle height HRL (HRR≈HRL). Further, when the right-side vehicle height HRR and the left-side vehicle height HRL are substantially the same, one-sided up control is not performed.

In S29, the vehicle height Hij is detected again for each of the front, rear, left, and right wheels, and in S30, it is determined whether or not the vehicle height is higher than the allowable vehicle height Ha. The permissible vehicle height Ha can be, for example, a height that makes the vehicle look unattractive when the vehicle height is higher than this. In this embodiment, the permissible vehicle height Ha is set to a height that is difficult to realize in practice.
When the vehicle height Hij for any of the front, rear, left, and right wheels is equal to or less than the allowable vehicle height Ha, the determination of S30 becomes NO, and the appearance improvement control ends. On the other hand, if the vehicle height HRR for the right rear wheel is higher than the allowable vehicle height Ha, the determination in S30 is YES, and in S31, air is discharged from the air cylinder 2RR of the right rear wheel. , The vehicle height HRR is lowered, and the allowable vehicle height is Ha or less. Specifically, as shown in FIG. 4, the circuit valves 62 and 63 are opened, the compressor 40 is operated, and the vehicle height control valve 26RR is opened. When the vehicle height HRR for the right rear wheel becomes equal to or less than the allowable vehicle height Ha, the vehicle height control valve 26RR is closed, the compressor 40 is stopped, and the circuit valves 62 and 63 are closed.
It should be noted that S29 to 31 may be executed before S20. Moreover, the execution of S29 to 31 is not indispensable.

In this embodiment, the appearance improvement control is performed as described above, and a specific example in that case will be described with reference to FIG.
As shown in FIGS. 9 (a), 9 (b), and 9 (c), when the door is opened (time T1) after the vehicle is stopped and the ignition switch 98 is turned off, FIG. 9 (f) ) Indicates, up-control is performed to raise the vehicle height to a height at which the occupants can easily get off. Then, when the occupant gets off (time T2), the load applied to each of the front, rear, left and right wheels changes, and for example, on the front wheel side, the left vehicle height may be higher than the right vehicle height. Further, since the door is opened and closed, the door open / close flag is turned ON as shown in FIG. 9D.

After that, as shown in FIG. 9E, when all the doors are switched from the unlocked state to the locked state (time T3), it is determined that the start condition is satisfied, and the appearance improvement control is performed. .. As shown in FIG. 9 (f), the vehicle height on the right side is lower than the vehicle height on the left side. Therefore, as shown in FIG. 8, air is supplied to the air cylinder 2FR of the front right wheel by one-sided up control, and the vehicle height HFR on the right side is increased. It is said to be almost the same height as the left vehicle height HFL. As a result, the inclination of the vehicle body 120 is reduced, and the appearance can be improved.
The specific example shown in FIG. 9 is just an example, and there are cases where the door is opened and closed with the ignition switch 98 turned on, and the vehicle height change that occurs when the occupant gets off is very small.

As described above, in the vehicle height control system according to the present embodiment, the target vehicle height suitable for the appearance improvement control is not determined, but the lower vehicle height of the right side vehicle height and the left side vehicle height is determined. , It is said to be almost the same height as the higher vehicle height. On the other hand, in the conventional vehicle height control system, the target vehicle height is determined based on the purpose of vehicle height control, the condition of the vehicle, the environment in which the vehicle is placed, etc., so that the actual vehicle height approaches the target vehicle height. Vehicle height control is performed. Therefore, if the purpose of vehicle height control, the condition of the vehicle, the environment in which the vehicle is placed, and the like are the same, the vehicle height after vehicle height control should always be the same. On the other hand, in the vehicle height control system according to the present embodiment, the purpose of the vehicle height control, the state of the vehicle, the environment in which the vehicle is placed, etc. are the same, the same start conditions are satisfied, and the appearance improvement control is performed. Even if it is done, the vehicle height after the appearance improvement control is usually different every time. As described above, the vehicle height control system according to the present embodiment is different from the conventional vehicle height control system.

As described above, in the present embodiment, the vehicle height control unit is composed of the appearance improvement control program of the vehicle height control ECU 80, the part that stores the start condition establishment determination program, the part that executes the program, and the like, among which S23, 24, 27, A one-sided up control unit is composed of a portion for storing 28, a portion for executing, and the like, and a down control unit is composed of a portion for storing S30 and 31 and a portion for executing. In addition, the appearance control start condition corresponds to the vehicle height control start condition.

The one-sided up control can be performed when the absolute value of the difference between the right-side vehicle height and the left-side vehicle height is larger than the set value on each of the front wheel side and the rear wheel side. The set value can be, for example, a size at which it can be determined that the left-side vehicle height and the right-side vehicle height are not substantially the same, or a size at which the vehicle body 120 is felt to be tilted in the left-right direction.

An example of the appearance improvement control in that case will be described with reference to the flowchart of FIG. Further, in the flowchart of FIG. 10, the same steps as those of the flowchart of FIG. 6 are assigned the same step numbers and the description thereof will be omitted.
In S41, on the front wheel side, it is determined whether or not the absolute value of the difference between the right vehicle height HFR and the left vehicle height HFL is larger than the set value ΔHth. If the determination is NO, one-sided up control is not performed, but if the determination is YES, the right-side vehicle height HFR and the left-side vehicle height HFL are compared in S21 to 24, and the lower one. The vehicle height is raised until it becomes almost the same as the vehicle height of the higher vehicle, and one-sided up control is performed. In this embodiment, it is considered that the determination of S22 is not NO.

In S42, on the rear wheel side, it is determined whether or not the absolute value of the difference between the right vehicle height HRR and the left vehicle height HRL is larger than the set value ΔHth. If the determination is YES, the right-side vehicle height HRR and the left-side vehicle height HRL are compared in S25 to 28, and the lower vehicle height is raised until it becomes almost the same as the higher vehicle height. One-sided up control is performed. Next, in S29 to 31, when the vehicle height is higher than the allowable vehicle height, the vehicle height is lowered to the allowable vehicle height.

Further, it is not indispensable to perform one-sided up control on each of the front wheel side and the rear wheel side, and one-sided up control is performed on either the front wheel side or the rear wheel side, and one side on the other side. Up control can be prevented.

Further, it is not essential that the appearance improvement control is performed when the start condition is satisfied, and it can be performed when the door open / close flag is turned ON. Further, for example, in the stopped state, it is constantly monitored whether or not the absolute value of the difference between the right side vehicle height and the left side vehicle height is larger than the set value, and when it becomes larger than the set value, the appearance improvement control is performed. You can also do it.

Further, the structure of the vehicle height control system is not limited to the above-described embodiment, and the present invention may be implemented in a mode in which various changes and improvements are made based on the knowledge of those skilled in the art, in addition to the mode described above. it can.

2: Air cylinder 19: Chamber 24: Air supply / exhaust device 26: Vehicle height control valve 30: Compressor device 34: Tank 40: Compressor 80: Vehicle height control ECU 90: Tank pressure sensor 93: Vehicle height sensor 98: Ignition switch 99 : Vehicle speed sensor 102: Door open / close sensor 104: Door lock sensor

Claimable invention

The patentable inventions will be described in the following sections.
(1) Right-sided vehicle height control actuators and left-sided vehicle height control actuators provided on the right and left wheels of the vehicle, respectively.
By supplying and discharging a pressure medium in each of the right-side vehicle height control actuator and the left-side vehicle height control actuator, the right-side vehicle height and the left-side wheel, which are the vehicle heights of the right-side wheels, are supplied and discharged, respectively. It is a vehicle height control system including a vehicle height control unit that controls each of the vehicle height on the left side and the vehicle height of the vehicle.
When the vehicle is stopped, the vehicle height control unit is assigned to either the right side vehicle height control actuator or the left side vehicle height control actuator corresponding to the lower of the right side vehicle height and the left side vehicle height. Includes a one-sided up control unit that performs one-sided up control that makes the lower vehicle height the same as the higher vehicle height of the right side vehicle height and the left side vehicle height by supplying the pressure medium. The vehicle height control system is characterized by this.
For example, when the vehicle height on the right side is lower than the vehicle height on the left side, the pressure medium is supplied to the vehicle height control actuator on the right side without supplying the pressure medium to the vehicle height control actuator on the left side. As a result, the height of the vehicle on the right side is increased to be almost the same as the height of the vehicle on the left side. When the vehicle height on the left side is lower than the vehicle height on the right side, the pressure medium is supplied to the vehicle height control actuator on the left side without supplying the pressure medium to the vehicle height control actuator on the right side. As a result, the height of the vehicle on the left side is increased to be almost the same as the height of the vehicle on the right side.
The "same height" means "almost the same height".

(2) The one-sided up control unit performs the one-sided up control when the absolute value of the difference between the right side vehicle height and the left side vehicle height is larger than the set value in the stopped state of the vehicle (2). The vehicle height control system described in item 1).
The set value can be set to a size that can be recognized as "the height of the vehicle on the right side and the height of the vehicle on the left side are not approximately the same height". Further, it can be set to a size that can be recognized as "the vehicle body is tilted in the left-right direction", or can be set to a size that can be recognized as "there is a high need to correct the tilt of the vehicle body in the left-right direction".

(3) The one-sided up control unit satisfies the vehicle height control start condition including that the vehicle is stopped, and when the right-side vehicle height and the left-side vehicle height are not the same height, the one-sided vehicle height is not the same. The vehicle height control system according to item (1) or (2), which performs up control.

(4) The vehicle height control unit is locked from the unlocked state after the vehicle height is stopped, the main switch of the vehicle is OFF, and the door of the vehicle is opened and closed. The vehicle height control system according to item (3), which includes a determination unit that determines that the vehicle height control start condition is satisfied when the condition of being switched to the state is satisfied.
It can be considered that the determination unit is composed of a portion for storing the start condition establishment determination program represented by the flowchart of FIG. 5 of the vehicle height control ECU 80, a portion for executing the determination program, and the like.

(5) When at least one of the right-side vehicle height and the left-side vehicle height is higher than a predetermined allowable vehicle height, the vehicle height control unit corresponds to at least one of the vehicle heights. Includes a down control unit that lowers at least one of the vehicle heights to or less than the allowable vehicle height by discharging the pressure medium from at least one of the right-side vehicle height control actuator and the left-side vehicle height control actuator (1). The vehicle height control system according to any one of items (4) to (4).
When the load applied to the wheels changes due to disembarkation, the vehicle height may become higher than the allowable vehicle height. However, if the vehicle height is higher than the allowable vehicle height, the appearance is poor. Therefore, in the vehicle height control system described in this section, when the vehicle height is higher than the allowable vehicle height, the vehicle height is lowered to the allowable vehicle height or less. As a result, the appearance of the vehicle in the stopped state can be improved. The vehicle height may be lowered to the allowable vehicle height or may be lowered to a height lower than the allowable vehicle height.

Claims (5)

Right-sided vehicle height control actuators and left-sided vehicle height control actuators provided on the right and left wheels of the vehicle, respectively.
By supplying and discharging a pressure medium in each of the right-side vehicle height control actuator and the left-side vehicle height control actuator, the right-side vehicle height and the left-side wheel, which are the vehicle heights of the right-side wheels, are supplied and discharged, respectively. It is a vehicle height control system including a vehicle height control unit that controls each of the vehicle height on the left side and the vehicle height of the vehicle.
When the vehicle height control unit is in a stopped state of the vehicle and (1) the door provided in the vehicle is opened, the height of the right side vehicle and the height of the left side vehicle are increased to a height suitable for getting off. As described above, the means for supplying the pressure medium to the right-side vehicle height control actuator and the left-side vehicle height control actuator, and (2) the right-side vehicle height and the left-side vehicle height after the door is closed. By supplying the pressure medium to either the right-side vehicle height control actuator or the left-side vehicle height control actuator corresponding to the lower one, the lower vehicle height can be changed to the right-side vehicle height and the left-side vehicle height. vehicle height control system comprising a one-side-up control unit for performing one-side-up control to the same height as the a higher height among the. When the vehicle height control start condition including the fact that the vehicle is in the stopped state and the vehicle is switched from the unlocked state to the locked state after the door is opened and closed is satisfied, the one-sided up control unit is said to be said. The vehicle height control system according to claim 1, wherein one-sided up control is performed. The vehicle height control system according to claim 1 or 2, wherein the one-sided up control unit performs the one-sided up control without determining a target vehicle height. When at least one of the right side vehicle height and the left side vehicle height is higher than a predetermined allowable vehicle height, the vehicle height control unit corresponds to the right side vehicle. Separate from the one-sided up control unit that lowers the vehicle height of at least one of the high control actuators and the left side vehicle height control actuator by discharging the pressure medium to make the vehicle height equal to or less than the allowable vehicle height. The vehicle height control system according to any one of claims 1 to 3, which includes a down control unit of the vehicle. Right-sided vehicle height control actuators and left-sided vehicle height control actuators provided on the right and left wheels of the vehicle, respectively.
By supplying and discharging a pressure medium in each of the right-side vehicle height control actuator and the left-side vehicle height control actuator, the right-side vehicle height and the left-side wheel, which are the vehicle heights of the right-side wheels, respectively. With the vehicle height control unit that controls each of the vehicle height on the left side
Is a vehicle height control system that includes
When the vehicle is stopped, the vehicle height control unit is assigned to either the right side vehicle height control actuator or the left side vehicle height control actuator corresponding to the lower of the right side vehicle height and the left side vehicle height. Includes a one-sided up control unit that performs one-sided up control that makes the lower vehicle height the same as the higher vehicle height of the right side vehicle height and the left side vehicle height by supplying the pressure medium. ,
The one-sided up control unit was switched from the unlocked state to the locked state after the vehicle was stopped and the door provided in the vehicle was opened and closed without determining the target vehicle height. A vehicle height control system that performs one-sided up control when a vehicle height control start condition including the above is satisfied.

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