JP3068870B2 - Controlled suspension for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a controllable suspension for a vehicle capable of changing a vehicle height value by supplying and discharging a working fluid of an actuator such as a hydraulic cylinder provided between a vehicle body and each wheel. And a control type suspension in which a vehicle speed range in which a vehicle height value can be changed is set.

[0002]

2. Description of the Related Art Conventionally, as a vehicle height adjusting device capable of changing a vehicle height value by supplying and discharging a working fluid of an actuator provided between a vehicle body and wheels, one disclosed in Japanese Patent Application Laid-Open No. Sho 62-178413 is known. .

[0003] This conventional device comprises a detecting means for detecting that the vehicle is stopped or running at a low speed, a distance measuring means for measuring a distance between a road surface and at least one portion of a lower part of the vehicle body and a lower part of a door lower part, When the detecting means detects that the vehicle is stopped or running at a low speed, interference determining means for comparing the distance measured by the distance measuring means with a preset interference risk distance, and this determining means When the measured distance is determined to be smaller than the interference risk distance, a correction means for setting the target vehicle height region or the target vehicle height value to be high. This prevents interference between a front overhang portion, a rear overhang portion, or a door lower portion and a convex portion such as a curb when the vehicle is stopped or traveling at low speed.

[0004]

The above-mentioned conventional device is,
Although this was effective in eliminating the interference between the vehicle body and the bumps on the road surface, it required distance measuring means such as a distance sensor and a signal processing circuit of the measuring means. , Paying attention only to height increase to prevent interference,
The vehicle height increase value is also automatically determined to a preset value, so if you want to lower the vehicle height value like putting a vehicle in a short garage, of course, you can also use It was not possible to meet the demand for raising the vehicle height to an arbitrary value based on the occupant's intention.

The present invention has been made in view of the above circumstances, and has been made in response to a further need for an arbitrary vehicle height. The structure can be simplified, and an allowable range at a relatively low speed can be determined by the occupant. It is an object of the present invention to make it possible to drive the vehicle at an arbitrary vehicle height value within the vehicle, and to automatically adjust the vehicle height value to a predetermined target value during high-speed traveling in other mediums.

[0006]

In order to solve the above problems, the present invention relates to a controllable vehicle suspension having an actuator capable of changing a stroke between wheels and a vehicle body, as shown in FIG. Vehicle speed detecting means for detecting, a mode selection switch capable of manually selecting an automatic adjustment mode relating to vehicle height adjustment or a manual up / down mode, and a first set value whose detected value of the vehicle speed detecting means is close to a value at the time of stopping First vehicle speed determination means for determining whether or not:
When the first vehicle speed judging means judges a vehicle speed state equal to or lower than a first set value and the mode selection switch judges a selection state of a manual up / down mode, the vehicle height from the mode selection switch is increased or decreased. A manual up / down command means for changing the stroke of the actuator according to the instruction content, and when the first vehicle speed determination means determines a vehicle speed state exceeding a first set value,
Second vehicle speed determining means for determining whether or not the detected value of the vehicle speed detecting means is equal to or greater than a second set value greater than the first set value; and a vehicle speed which is lower than the second set value. Condition
State is determined and the mode selection switch is manually
When the down mode selection state is determined,
Maintaining the stroke of the eta, but when the second vehicle speed determining means determines a vehicle speed state less than a second set value and the mode selection switch determines an instruction state of the automatic adjustment mode; and When the determining means determines a vehicle speed state equal to or higher than a second set value, an automatic adjustment instruction means for instructing the actuator to make the actual vehicle height follow the vehicle height target value is provided.

[0007]

[Operation] It is assumed that the occupant has selected the manual up / down mode with the mode selection switch. The first vehicle speed determining means determines whether or not the detected vehicle speed is substantially equal to or less than a first set value and is in a state close to a stop. If the vehicle is in a stop or a state close to a stop, the mode selection switch is checked. . As a result,
If the manual up / down mode is selected, the manual up / down command means activates the actuator according to the content of the selected manual mode. An arbitrary vehicle height value is set within.

When the first vehicle speed determining means determines at least that the vehicle is not at a stop or near a stop, the second vehicle speed determining means determines that the detected vehicle speed is equal to or greater than a second set value. It is determined whether or not the vehicle is traveling at a high speed. If the result of this determination is that the vehicle is not in the middle / high-speed driving state and the manual mode of the mode selection switch is further determined, the control for the actuator is not performed. When a vehicle height value exceeding (or below) the value is set, even if the vehicle speeds up to a predetermined speed state of “first set value <vehicle speed <second set value”, the speed state is based on the intention of the occupant. It can run with the vehicle height.

However, when the second vehicle speed judging means judges that the vehicle is in a high-speed running state, the automatic adjustment instructing means is activated, so that the stroke amount of the actuator is set to the actual vehicle height value = the target value by the instructing means. Automatically adjusted to In addition, even when the vehicle is stopped or near the stop and the predetermined speed state is determined, the vehicle height adjustment is performed by the automatic adjustment command unit when the automatic adjustment mode is selected by the mode selection switch.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In this embodiment, the invention is applied to a full hydropneumatic suspension which receives a load by a force generated by a hydraulic cylinder.

2 and 3, 2FL to 2RR denote front left to rear right wheels, 4 denotes a wheel side member, 6 denotes a vehicle body side member, and 8 denotes a control type suspension. The control type suspension 8 includes a hydraulic pump 10 and an oil tank 12 serving as a hydraulic pressure source as a fluid pressure source, an accumulator 14 disposed on the load side of the hydraulic pressure source, and a check valve 1.
6. Hydraulic source side oil passage opening / closing unit 18, front wheel side and rear wheel side oil passage opening / closing units 20F, 20R, suspension characteristic variable units 22FL-22RR installed for each wheel 2FL-2RR, and hydraulic cylinder as actuator Mode selection switch 2 that allows manual selection of 24FL-24RR and vehicle height adjustment mode
5, vehicle height sensors 26FL-26RR for vehicle height detection, pressure sensors 27FL-27RR for pressure detection, an acceleration sensor 28, a vehicle speed sensor 29, and a controller 30.

Among them, the hydraulic pump 10 is constituted by a tandem type pump which rotates by using a vehicle engine as a drive source, and discharges hydraulic pressure to a power steering device and a hydraulic suspension 8. The suction side of the hydraulic pump 10 is connected to the oil tank 12 by a pipe 31, and the discharge side thereof is connected to a pipe 32. The load side of the pipe 32 is communicated with the pulsation absorbing accumulator 14, and the hydraulic source side oil passage opening / closing section 18 is connected via a check valve 16.
Connected to.

The oil passage opening / closing portion 18 comprises an electromagnetically operated two-port unload valve 34, a relief valve 36 having a predetermined relief pressure, and a divider 38 for distributing the oil passage to the front and rear wheels. The load valve 34, the relief valve 36, and each port on the hydraulic pressure source side of the flow divider 38 communicate with each other. Unloading valve 34, the control signals S ₁ supplied to the electromagnetic solenoid takes the communicating position when off, the control signal S ₁ is take blocking position when on, always has an open structure.
The tank-side ports of the switching valve 34 and the relief valve 36 are connected to the oil tank 12 by a pipe 40.
A filter 42 for filtration is inserted in the middle of the pipe 40. The pipe 32 is connected to the two ports on the load side of the flow divider 38.
F and 32R are connected to each other, and the pipes 32F and 32R are connected to the front-wheel-side and rear-wheel-side oil passage opening / closing portions 20F and 20R, respectively.

The front-wheel-side oil passage opening / closing section 20F is provided with a flow divider 42F having an input port connected to a pipe 32F at a position on the hydraulic pressure source side, and a flow limiting type check valve 44FL, 44FR is provided on the load side of the flow divider 42F. , Electromagnetically operated 2-port switching valves 46FL, 46FR, communication valve 48F, and relief valve 5
It has 0FL and 50FR. More specifically, two load-side ports of the flow divider 42F are connected to one ends of pipes 32FL and 32FR corresponding to the front left and front right wheels, respectively. The other end of the pipe 32FL on the front left wheel side is a check valve 44FL,
It communicates with one port of the communication valve 48F and the high pressure side port of the relief valve 50FL via the switching valve 46FL, and reaches the front left wheel side suspension characteristic variable section 22FL. Similarly, the other end of the pipe 32FR on the front right wheel side has a check valve 44.
It communicates with the other port of the communication valve 48F and the high pressure side port of the relief valve 50FR via the FR and the switching valve 46FR, and reaches the front left wheel side suspension characteristic variable section 22FR.

[0015] piping 32FL, switching valve 46FL interposed in series each 32FR, 46FR takes the blocking position due to the check valve control signal S ₂ to be supplied to the electromagnetic solenoid is incorporated in the off, control signal S ₂ takes the communicating position when on, has a normally closed structure. In addition, piping 3
2FL, even communication valve 48F that is interposed between 32FR, taking a cut-off position due to the check valve control signal S ₃ which is supplied to the electromagnetic solenoid is incorporated in the off, the control signal S ₃
Takes a communication position when is turned on, and has a normally closed structure.

Further, the rear-wheel-side oil passage opening / closing section 20R is also provided with a flow divider 42R for diverting hydraulic oil to the rear left and rear right wheels, flow-limiting check valves 44RL and 44RR, and a solenoid-operated two-port switching valve 46RL. 46RR, a communication valve 48R, and relief valves 50RL, 50RR are provided, and are connected in the same manner as the front wheels via pipes 32RL, 32RR. Here, each of the relief valves 50FL to 50RR is for preventing an abnormal pressure rise on the load side, and is set to a predetermined relief pressure higher than a normally available pressure range. It is connected to the.

Suspension characteristic variable parts 22FL-22RR
Each have a free piston type first and a first gas spring.
Second accumulators 54 and 56, a two-port switching valve 58 for changing a spring constant, and a variable throttle 6 for generating a damping force.
0. The first accumulator 54 is directly connected to the pipe 32FL, the second accumulator 56 is connected via the switching valve 58, and the pipe 3FL is connected to the pipe 32FL.
A variable aperture 60FL is inserted in series with 2FL. Switching valve 58 that opens the motor 58A as an actuator, a closed position is switched, the motor 58A is rotated by a drive signal S _4. Therefore, the switching valve 58
Is closed and the second accumulator 56 is disconnected from the hydraulic circuit, only the first accumulator 54 is effective, so that the spring constant characteristic becomes hard. On the other hand, when the switching valve 58 is open, both the first and second accumulators 54 and 56 function effectively, and the spring constant characteristic becomes soft.

The variable throttle 60 is also urged by the rotation of the motor 60A to adjust the width and width of its flow path.
Drive signal S ₅ are supplied to the. Furthermore, each of the hydraulic cylinders 24FL to 24RR is configured as a single-acting type as shown in FIG. 3, and a pressure chamber L separated by a piston 24b is formed in the cylinder tube 24a. A pipe 32FL (up to 32RR) is connected to the pressure chamber L. And, the front wheel side hydraulic cylinders 24FL, 24
In FR, the cylinder tube 24a is attached to the wheel side member 4, the end of the piston rod 24c is attached to the vehicle body side member 6, and conversely, the rear wheel side hydraulic cylinder 24
In RL and 24RR, the cylinder tube 24a is attached to the vehicle body-side member 6, and the end of the piston rod 24c is attached to the wheel-side member 4.

In FIG. 3, the mode selection switch 25 has an operation section for a "normal" position, an "up" position, and a "down" position which can be manually selected. The "normal" position corresponds to a vehicle height adjustment that follows a preset vehicle height target value, and the indicator light is turned on by a push operation to enable selection of the position, and such a state changes the other manual mode position. Locked until pressed. The "up" and "down" positions correspond to control for manually raising and lowering the vehicle height based on the intention of the occupant, and by pressing the positions, the previously selected position is automatically released and switched to the manual mode ( At this time, the indicator at the up or down position lights up), while the up or down command is valid only while the button is pressed, and when the pushing operation is stopped, the display stands by at that position in a display state (non-selected state). Therefore, the mode selection switch 25 sends the mode selection signal SL having a value corresponding to the position selected by pressing the operation unit to the controller 3.
The switch signal SW is turned off in a non-selection standby state after outputting to 0 and releasing the push of the up or down position. After the power is turned on, the mode selection switch 2
5 is always automatically initialized to the "normal" position.

Further, the vehicle height sensors 26FL~26RR is constituted by a potentiometer or the like, and outputs the vehicle height signal H _FL to H _RR of the voltage value corresponding to the relative distance amount (stroke amount) to the controller 30. The pressure sensors 27FL to 27RR are shown in FIG.
As shown in the figure, the front and rear wheel side oil passage opening / closing portions 20F, 20F
R are connected to the load side positions of the pipes 32FL to 32RR, respectively, and the pressures at the connection positions are adjusted by the hydraulic cylinders 24FL to 24RR.
And outputs to the controller 30 pressure signals P _{FL to} P _RR having voltage values corresponding to the internal pressures.

The acceleration sensor 28 is provided at a predetermined position on the vehicle body, and outputs a signal G to the controller 30 according to the acceleration acting on the vehicle body in the lateral (vehicle width) direction, the front-rear direction, and the like. The vehicle speed sensor 29 outputs a signal V corresponding to the vehicle speed to the controller 30 by, for example, detecting the rotation speed of the output shaft of the transmission.

As shown in FIG. 4, the controller 30 inputs the vehicle height detection signals H _{FL to} H _RR and the pressure detection signals P _{FL to} P _FL.
Gain adjuster 7 for multiplying _RR and acceleration detection signal G by gain
0, an A / D converter 72 for digitizing the output of the gain adjuster 70 and the mode selection signal SL, an interface circuit 74 for inputting the vehicle speed detection signal V, and an A / D
A microcomputer (C) that takes in output signals of the converter 72 and the interface circuit 74 and performs predetermined processing.
PU) 76, and a drive circuit 78 for driving each solenoid and motor in accordance with the control signal output from the computer 76. Further, the controller 30 has a mechanism for keeping the power on for a predetermined time even after the ignition switch is turned off.

The microcomputer 76 includes a mode selection signal SL, a vehicle speed signal V, an acceleration signal G, and a vehicle height signal H _FL .
The H _RR and the pressure signals P _{FL to} P _RR are input and the vehicle height is adjusted according to the vehicle speed state and the mode selection state as shown in FIG. 5, while the spring constant and the damping constant are also controlled. ing.

Next, the operation of this embodiment will be described. First, the flowchart of FIG. 5 executed by the controller 30 will be described. The process of FIG. 5 is a schematic program for adjusting the vehicle height, is started when the power is turned on, and is continued until the power is turned off.

The processing of FIG. 5 will be described. Controller 30
The microcomputer 76 performs predetermined initialization (including clearing of the flags FU and FD) in step 100 of the figure, reads a vehicle speed signal V via the interface circuit 74 in step 101, and outputs the read value to the vehicle speed. To be stored. Next, the routine proceeds to step 102, where the microcomputer 76 determines whether or not the vehicle speed V ≦ V _{1 with} respect to the first set value V ₁ of the vehicle speed set in advance. The first set value V ₁ is set to V ₁ =, for example, 5 km / h in order to determine whether the vehicle is stopped or almost stopped.

Next, the computer 76 proceeds to step 103
After reading the mode selection signal SL related to the mode selection switch 25, the determination in step 104 is performed. In step 104, it is checked whether or not the mode selection signal SL = OFF, so that the mode selection switch 2
It is determined whether or not 5 is in a non-selection state, that is, a state in which, after a command for the up or down manual mode is issued, the mode selection display is on standby. If the determination is NO, that is, if any position has been selected, the process further proceeds to step 105, where it is determined whether or not the "normal" position has been selected by discriminating the value of the switch signal SL.
In the case of NO in this determination, the computer 76 further proceeds to step 106 to determine whether or not it is the manual mode up command from the value of the signal SL.

If the determination in step 106 is YES
Then, the processing of steps 107 to 110 is performed.
In step 107, the vehicle height sensors 26FL to 26RR are detected.
Signal H _FL~ H_RRIs the gain adjuster 70 and the A / D converter 7
2 and read the values between the wheels and the car body.
It is stored for each wheel as a trooke amount, that is, a vehicle height value. Next
In step 108, the read value H in step 107
(: H_FL~ H_RR) = EH is determined. here,
The vehicle height EH is the maximum vehicle height that can be manually adjusted,
EH> N with respect to the target value N at the time of adjusting the vehicle height (see FIG.
6). Therefore, in step 108, NO,
Height H of each wheel_FL~ H_RRHas not reached the maximum value EH
If there is still room to manually raise the vehicle height,
The process proceeds to step 109, and a command to increase the height of the four wheels is issued.
You.

The vehicle height increasing command in step 109 is issued by the computer 76 instructing the drive circuit to set the control signal S ₁ : ON, the control signal S ₂ for the four wheels: ON, and the control signal S ₃ before and after: OFF. Done. As a result, the unload valve 34 in the oil passage opening / closing portion 18 is closed, the electromagnetic switching valves 46FL-46RR of the front wheel side and rear wheel side oil passage opening / closing portions 20F, 20R are opened, and the communication valves 48F, 48R are closed. The hydraulic oil discharged from the hydraulic pump 10 is a hydraulic cylinder 24FL.
~ 24RR. As a result, the stroke of each of the hydraulic cylinders 24FL to 24RR increases at a constant speed, and the vehicle height value increases.

After the command in step 109 is completed, the flag FU is set to 1 in step 110 to indicate that the vehicle height is being increased, and then in step 103
Return to the processing of. On the other hand, if the vehicle height values H _{FL to} H _RR have reached the maximum value EH during such manual up, step 1 is executed.
The process is forcibly returned to step 101 via 11 to 113. In step 111, the flag FU or FD =
It is determined whether the value is 1 or not. If YES, the process proceeds to step 112, and the computer 76 instructs to stop the vehicle height manual adjustment. Specifically, the stop command is issued by setting the control signal S ₁ : off, the control signal S ₂ for the four wheels: off, and the preceding and following control signals S ₃ : off. by this,
The unload valve 34 is opened, the electromagnetic switching valves 46FL to 46RR are closed, the communication valves 48F and 48R are closed, and the hydraulic oil of the hydraulic cylinders 24FL to 24RR is sealed. Is held at the value of And step 1
In step 13, the manual vehicle height adjustment is stopped (the maximum value EH, the minimum value EL).
Flag FU, to indicate a forced suspension due to the arrival of the vehicle, and a voluntary suspension at an arbitrary vehicle height.
FD = 0 is set, and the process returns to step 101.

On the other hand, if NO in step 106, that is, if it is determined that the vehicle height is to be manually reduced, the processing of steps 114 to 117 is performed thereafter. In step 114, the current vehicle height values H _{FL to} H _RR of the respective wheels are read in the same manner as in step 107, and in step 115, the preset minimum value EL for manual adjustment (<reference target value N: see FIG. 6). It is determined whether or not the vehicle height value H (: H _{FL to} H _RR ) = EL. In the case of NO in this step 115, it is recognized that if the occupant wants, there is still room for the vehicle height reduction, and in step 116, the vehicle height reduction command of each wheel is issued.

The vehicle height down command in the manual mode is controlled by the computer 76 by the control signal S from the drive circuit 78.
₁ : off, control signal S ₂ for four wheels: on, front and rear control signal S ₃ : off. As a result, the unload valve 34 opens, and the electromagnetic switching valves 46FL-46
When RR is opened and the communication valves 48F and 48R are closed and the hydraulic oil of the hydraulic cylinders 24FL to 24RR is individually returned to the tank 12, the vehicle height value of each wheel decreases at a constant speed. After that, the computer 76 sets the flag FD indicating the vehicle height down state in step 117, and returns to the processing in step 103.

If the result of the determination in step 115 is YES while the vehicle height is being reduced manually, it is determined that further reduction is ineffective, and the above-described step 1 is not performed.
The process from 11 to 113 is performed, and the process returns to step 101.

In the up adjustment in steps 107 to 110 and the down adjustment in steps 114 to 117,
When the vehicle height value of one of the wheels reaches the maximum value EH and the minimum value EL earlier than the others due to the load variation between the wheels,
After that, the control is continued only for the non-arrival.

On the other hand, YE
If S is determined, two states are assumed. In other words, after the engine has been started and the power has been turned on, if the occupant has not selected the manual up / down mode, or once selected the manual up / down mode, This is the case where the occupant selects the normal position. Therefore, the computer 76 performs the processing of steps 118 to 120, which is the same processing content as the above steps 111 to 113, and then proceeds to step 121.

The processing in step 121 depends on the intention of the occupant.
"Normal" position
Is the vehicle height adjustment process when
In the embodiment, the front and rear communication valves are set according to the load condition and the vehicle speed condition.
48F, 48R in the state of communication with either
So-called three-axis control (for example, JP-A-63-154).
No. 413). In other words, MicroCo
The computer 76 detects the detection signals of the vehicle height sensors 26FL to 26RR.
Issue H_FL~ H_RR, The average vehicle height is the target vehicle height N
Judge whether the vehicle has deviated from the vehicle.
Is performed using the three-axis control method.
U. When increasing the vehicle height, the control signal S ₁On, before
Control signal S for any of the rear wheels_ThreeAnd turn on each control signal.
No. S_TwoIs turned on. This allows unloading
The valve 34 is closed, and the communication valve 48F, 48R of any of the front and rear wheels
Is open and each of the switching valves 46FL-46RR is open.
The hydraulic oil discharged from the pump 10 is
It flows into ~ 24RR and the vehicle height increases. Conversely, vehicle height
To bring down the control signal S₁Off, front and rear wheels
Control signal S_ThreeIs turned on, and each control signal S_TwoTo
Performed as ON. As a result, the unload valve 34
Open, communication valve 48F, 48R of either front or rear wheel is open
State, each of the switching valves 46FL to 46RR is opened and the hydraulic
24FL ~ 24RR hydraulic oil flows into tank 12 and
High down. In addition, taking the vehicle speed value V into consideration,
Then, the target vehicle height value may be lowered.

When the process of following the vehicle height target value N is completed by the three-axis control, the computer 76 proceeds to step 1
Return to 01. On the other hand, if YES in step 104, that is, if it is determined that the mode selection switch 25 has not been selected, it means that the vehicle is in the standby state at an arbitrary vehicle height once the manual up / down control has been performed. The processing of steps 111 to 113 is performed. In other words, after the transition to the standby state (after releasing the operation unit at the “up” or “down” position), steps 111 to 113 are processed for the first control, and after the second control, step 111 is processed. The process returns to step 101.

If NO in step 102, the flow proceeds to step 122 on the assumption that the vehicle is not at a stop or at a vehicle speed close to the stop. In step 122, the computer 7
6 is a vehicle speed value V ≧ with respect to a second set value V ₂ (for example, a value at 20 km / h to 30 km / h) that can discriminate between low speed and medium / high speed
Determines whether the V ₂ or not. If a negative determination is made in step 122, it is determined that the vehicle is traveling at a low speed, and the same processing as steps 103 to 105 described above is performed in step 123.
To 125.

That is, at step 123, the mode selection signal SL is read. At step 124, it is determined whether or not the switch is in the non-selection state. It is determined whether or not the selection is made. For this reason, when the selection of the normal position is determined in step 125, the process returns to step 101 after the vehicle height adjustment is performed by the process of step 121. However, when the manual up or down position is determined in step 125, the computer 76 does not participate in the supply / discharge control of the hydraulic oil of the hydraulic cylinders 26FL to 26RR at all, and holds the stroke amount at that time. Returning to step 101, the above-described processing is repeated. Also, if YES in step 124, that is, in the non-selection state, the process returns to step 101 similarly.

On the other hand, in step 122, V ≧ V
When it is determined that the condition ₂ is satisfied, the vehicle is in the medium speed or high speed running state, so that it is recognized that traveling at an arbitrary vehicle height by the occupant is not possible, and the switch signal SL of the mode selection switch 25 is not determined, and The process of step 121 is directly performed, and thereafter, the process returns to step 101.

In the above configuration and processing, the vehicle speed sensor 29, the interface circuit 74, and step 1 in FIG.
01 constitutes the vehicle speed detecting means, and the processing of step 102 in FIG. 5 constitutes the first vehicle speed determining means.
Constitutes the second vehicle speed determination means. Further, the processing of steps 103 to 105 in FIG. 5 constitutes a first mode determination means, and the processing of steps 123 to 125 in FIG. 5 constitutes a second mode determination means. Further, vehicle height sensors 26FL to 26RR, gain adjuster 70, A / D converter 72, and steps 106 to 106 in FIG.
The process 117, the drive circuit 78, the unload valve 34, the electromagnetic switching valves 46FL to 46RR, and the communication valves 48F and 48R constitute manual up / down command means. Further, vehicle height sensors 26FL-26RR, gain adjuster 70, A / D converter 7
2, the processing of steps 118 to 121 and 123 to 125 in FIG. 5, the drive circuit 78, the unload valve 34, the electromagnetic switching valves 46FL to 46RR, and the communication valves 48F and 48R constitute automatic adjustment instruction means.

Next, the overall operation of this embodiment will be described with reference to FIG. First, when the ignition switch is turned on, the control type suspension 8 is activated. As a result, the "normal" position is automatically selected by the mode selection switch 25 as the initial mode. Therefore, the microcomputer 76 performs control through steps 100 to 105, 118, and 121 in the processing of FIG. 5 described above, so that the actual vehicle height value is set to the target value N (see FIG. 6) based on automatic adjustment related to the three-axis control. ).

However, it is assumed that the occupant presses the operation portion of the mode selection switch 25 at the "up" position in a state where the vehicle is stopped in the idling state or in an extremely low speed state that can be regarded as a stop. While this pushing operation is continued, the computer 76
Repeats the processing of steps 103 to 110 in FIG. 5, so that the vehicle height value of the four wheels is increased from the reference target value N at a constant speed in an extra high state. Then, when the occupant releases the push operation on the operation unit at the “up” position, the automatic up is stopped (steps 104 and 1 in FIG. 5).
11 to 113), an arbitrary vehicle height value related to the extra high at that time is held.

After obtaining the extra high vehicle height value, the non-selected state is maintained unless the occupant presses the operation unit at the "normal" position of the mode selection switch 25. Therefore,
Even when accelerated in this non-selected state, if the vehicle speed value V is smaller than the second set value V _2, it does not participate in the supply and discharge of working oil hydraulic cylinder 26FL～26RR (Figure 5 Step 101,1
From 02,122～124 reference) allows travel in EH ₁ showing vehicle height value of the extra high, in FIG. 6 for example, at a low speed state of the second lower than the set value V _2. As a result, the vehicle can be slowly moved with the vehicle height value higher than the normal target value N by performing, for example, manual extra control for extra high when the tire is mounted, so that the work becomes easier than before.

However, if it is determined that the vehicle speed value V has reached the second set value V ₂ due to the acceleration and the vehicle has entered the medium speed state, there is no room for detecting the mode selection state, and Car height adjustment is performed (FIG. 5, step 102,
122, 121), the vehicle height is forcibly set to the target value N (see arrow a in FIG. 6). For this reason, the vehicle height does not accidentally become too low or too high at middle or high speeds, so that it is possible to accurately prevent interference with the road surface and unstable running.

Further, it is assumed that the occupant presses the operating portion at the "normal" position from the non-selected switch state while the vehicle speed is in the low speed range which is the arbitrary vehicle height holding region. As a result, the controller 30 instructs normal automatic adjustment (see YES in step 125 in FIG. 5), so that the vehicle height value can be forcibly returned to the target value N by the occupant's intention (see arrow b in FIG. 6).

On the other hand, when the occupant is in the idling state or in an extremely low speed state that can be regarded as stopping, the occupant operates the mode selection switch 25.
It is assumed that the operation unit at the “down” position is pressed. While the pushing operation is continued, the vehicle is in an extra low state in which the vehicle height values of the four wheels decrease at a constant speed from the reference target value N (see steps 103 to 116 and 114 to 117 in FIG. 5). Then, the automatic down is stopped when the occupant releases the push operation on the operation unit at the “down” position (FIG. 5).
Steps 104, 111-113), an arbitrary vehicle height value related to the extra low at that time is held.

After the extra low vehicle height is obtained, the non-selected state is maintained unless the occupant presses the operation section of the mode selection switch 25 at the "normal" position. Therefore,
Even when accelerated in this non-selected state, if the vehicle speed value V is smaller than the second set value V _2, it does not participate in the supply and discharge of working oil hydraulic cylinder 26FL～26RR (Figure 5 Step 101,1
From 02,122～124 reference) allows travel in EL ₁ showing vehicle height value of the extra low, in FIG. 6 for example, at a low speed state of the second lower than the set value V _2. As a result, for example, by performing the manual down control of the extra low when loading / unloading the luggage, the vehicle can be slowly moved with the vehicle height lower than the normal target value N, so that the work becomes easier than before. . In addition, parking in a short garage becomes easy.

However, when it is determined that the vehicle speed value V has reached the second set value V ₂ due to the acceleration and the vehicle has entered the medium speed state, the vehicle height adjustment relating to the target value N is forcibly performed as described above. This is performed (see steps 102, 122, and 121 in FIG. 5). Further, in a state where the vehicle speed is in the low speed range of V ₂ less,
If the occupant presses the operation unit at the “normal” position from the non-selected switch state, the operation can be forcibly shifted to normal automatic adjustment (see arrow c in FIG. 6).

On the other hand, in the present embodiment, a mode selection switch is provided, and the switch signal is processed by a controller for vehicle height control and attitude control. Therefore, a conventional distance sensor and its signal processing are not required. Therefore, the configuration can be simplified.

The actuator according to the present invention is not necessarily limited to the one using a hydraulic cylinder as described above. For example, it is possible to use a working fluid as air, and to supply and discharge the air to expand and contract a stroke. The air chamber by the body may be provided between the vehicle body and the wheels.
Further, instead of the microcomputer, the controller may use an analog electronic circuit, a logic circuit, or the like configured to perform equivalent functions.

[0051]

As described above, according to the present invention, the mode selection switch for manually selecting the automatic adjustment mode relating to the vehicle height adjustment or the manual up / down mode is provided, and the vehicle speed detection value is close to the value at the time of stopping. It is determined whether the state is equal to or less than the first set value. When the vehicle speed state is equal to or less than the first set value, the selection of the mode selection switch is determined, and the result of the determination is the selection of the manual up / down mode. At this time, the stroke of the actuator is changed according to the contents of the vehicle height increase / down instruction from the mode selection switch, and when the vehicle speed state in which the vehicle speed detection value exceeds the first set value is determined, the vehicle speed detection value is further determined. There second determines whether the setting value or more of the vehicle speed state is greater than the first set value, when the vehicle speed state less than the second set value so as to determine the choice of the mode selection switch And manually A vehicle speed is less than the second set value
Actuate when up / down mode is selected
Maintaining the stroke of eta, when the vehicle speed automatic adjustment mode is selected be less than the second set value, and, when the vehicle speed is the vehicle speed state than the second set value is determined, car vehicle height value An automatic adjustment to match the high target value was commanded to the actuator.

For this reason, the conventional distance measuring means and the like are not required, and the configuration can be simplified. On the other hand, when the vehicle speed is equal to or less than the first set value and the vehicle is stopped or close to being stopped, the mode selection switch is used to manually increase the speed. By selecting the down mode, it is possible to manually increase or decrease the vehicle height to an arbitrary value within the set range without giving an occupant a feeling of anxiety due to a change in vehicle height and maintaining a state of ensuring visual measurement accuracy due to manual operation. Can be down. Moreover, the mode select switch manual up / down mode can be set from this arbitrary vehicle height state.
When the vehicle travels while being selected , if the vehicle speed value is less than the second set value, the vehicle can travel with the manually adjusted arbitrary vehicle height value. That is, in the present invention, the vehicle speed range below the second set value is
When the automatic adjustment mode is selected with the mode selection switch
Except for the speed range that can hold an arbitrary vehicle height, the vehicle can be moved with the vehicle height value higher than the normal target value when the tire chain is attached, or lowered below the normal target value when unloading luggage, the vehicle height value The work can be facilitated by moving the vehicle as it is, and even when the entrance height of the garage is low, the vehicle height can be reduced to an arbitrary height and the garage can be put into the garage as it is.

Further, when the vehicle speed reaches a middle / high speed state in which the vehicle speed exceeds the second set value, automatic tracking control to an appropriate target value is performed without giving room for mode selection. Under- and over-height values associated with the manual operation can be eliminated, and thereby interference with the road surface and unstable running can be accurately prevented.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims.

FIG. 2 is a partial configuration diagram of a control type suspension, showing one embodiment of the present invention together with FIG. 3;

FIG. 3 is a partial configuration diagram of a control type suspension, showing one embodiment of the present invention together with FIG. 2;

FIG. 4 is a block diagram illustrating a configuration of a controller.

FIG. 5 is a flowchart illustrating an example of a processing procedure in a controller.

FIG. 6 is an explanatory diagram showing a relationship between a vehicle speed and a vehicle height value.

[Explanation of symbols]

 8 Control Type Suspension 24FL-24RR Hydraulic Cylinder 25 Mode Selection Switch 26FL-26RR Height Sensor 29 Vehicle Speed Sensor 30 Controller 34 Unload Valve 46FL-46RR Electromagnetic Switching Valve 48F, 48R Communication Valve 76 Microcomputer

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuo Mori 2548 Kayaba Industrial Co., Ltd., Kayaba Industrial Co., Ltd., Gifu-Kita Plant (72) Inventor Koji Takase 2548 Tsuchida, Kagi City, Gifu Pref. 72) Inventor Kani Asahi 2548 Tsuchida, Kani City, Gifu Prefecture Kayaba Industrial Co., Ltd. Gifu North Plant (56) References JP-A-62-94409 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B60G 17/005 B60G 17/015

Claims (1)

(57) [Claims] A vehicle control type suspension having an actuator capable of changing a stroke between a wheel and a vehicle body, a vehicle speed detecting means for detecting a vehicle speed, and an automatic adjustment mode relating to vehicle height adjustment or a manual up / down mode. A manually selectable mode selection switch, first vehicle speed determining means for determining whether or not the detected value of the vehicle speed detecting means is equal to or less than a first set value close to a value at the time of stopping, and first vehicle speed determining means Is the first
When a vehicle speed state equal to or less than a set value is determined and the mode selection switch determines a selection state of the manual up / down mode, the stroke of the actuator is changed according to the vehicle height up / down instruction from the mode selection switch. And manual up / down command means for changing the vehicle speed. When the first vehicle speed determining means determines a vehicle speed state exceeding a first set value, the detected value of the vehicle speed detecting means is set to the first speed.
A second vehicle speed determining means for determining whether the second set value or more larger than the set value, the second vehicle speed determining means second set
Judgment of the vehicle speed condition below the fixed value and the mode selection switch
Switch has determined that the manual up / down mode has been selected.
When the stroke of the actuator is maintained, the second vehicle speed determining means determines a vehicle speed state lower than a second set value and the mode selection switch determines an instruction state of an automatic adjustment mode, and A vehicle which is provided with automatic adjustment command means for giving, to the actuator, a command for causing an actual vehicle height value to follow a vehicle height target value when the second vehicle speed determination means determines a vehicle speed state equal to or higher than a second set value. Control type suspension.