JPH0624882B2 - Vehicle height adjustment device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vehicle height adjusting device for an automobile or the like.

(Prior Art) For example, as described in Japanese Patent Publication No. 56-7891, there is known a vehicle height adjusting device for a vehicle such as an automobile, which keeps the vehicle height constant irrespective of a load. .

(Problems to be Solved by the Invention) However, if the vehicle height is kept constant irrespective of the load, etc., when the opening / closing body such as the door, the trunk lid, or the fuel cap is opened, Getting on and off,
There is a problem that load fluctuations occur due to loading and unloading of luggage, refueling, etc., and the vehicle height is frequently adjusted, which causes noise and the like to cause discomfort.

The present invention, in a vehicle height adjusting device for an automobile or the like, frequently changes an upper limit value and a lower limit value of a target vehicle height value at the time of adjusting the vehicle height depending on the open / close state of an opening / closing body such as a door provided on a vehicle body. The purpose is to eliminate unnecessary vehicle height adjustment.

(Means for Solving the Problem) The present invention includes a liquid chamber whose volume can be changed between a vehicle body and an axle, adjusts the fluid in the fluid chamber, and changes the volume of the fluid chamber to adjust the vehicle height. Assuming a vehicle height adjustment device,
An opening / closing body opening / closing detection means for detecting opening / closing of the opening / closing body provided to be openable / closable on the vehicle body, a vehicle height detecting means for detecting a vehicle height, and an opening / closing body opening / closing means for receiving an output from the opening / closing body opening / closing detection means. Sometimes the upper limit of the vehicle height target value is corrected upward and / or the lower limit is corrected downward, and when the opening / closing body is opened, the target vehicle height value is wider than when the opening / closing body is closed. Receiving the outputs of the lower limit value changing means, the vehicle height detecting means and the upper limit value / lower limit value changing means, and only when the current vehicle height is larger than the upper limit value or smaller than the lower limit value of the target vehicle height value, the fluid Vehicle height control means for adjusting vehicle height by adjusting the fluid in the room and changing the volume of the fluid chamber.

(Operation) When the opening / closing body is opened, the upper limit / lower limit value changing means performs at least one of upward correction of the vehicle height target value and downward correction of the lower limit value, thereby opening the opening / closing body. At times, the width of the target vehicle height value is made wider than when the opening / closing body is closed. As a result, the vehicle height is adjusted by adjusting the liquid in the fluid chamber and changing the volume of the fluid chamber only when the current vehicle height is larger than the upper limit value or smaller than the lower limit value of the target vehicle height value. Open and close the trunk lid, fuel cap, doors, etc. to load and unload luggage, refuel, and get on and off passengers.When opening and closing the body, the frequency of vehicle height adjustment is It will be less than when it is closed, and the vehicle height will not be adjusted due to frequent vehicle height adjustments.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In FIG. 1 showing the overall configuration, reference numeral 1 denotes a vehicle body of an automobile or the like, and an axle 2 is supported on the vehicle body. Body 1 and axle 2
A fluid chamber 3 whose volume can be changed is disposed between the fluid chamber 3 and the fluid chamber 3.
And a hydraulic pump 4 for supplying pressure oil to the fluid chamber 3.
Are linked via the electromagnetic switching valve 5.

The hydraulic pump 4 is driven by a motor 4a and pressure-feeds the hydraulic oil in the oil tank 4b. The electromagnetic switching valve 5 is configured as a 3-position 4-port type, and the hydraulic pump 4
The discharge side pipeline 10 and the return pipeline 11 to the oil tank 4b are connected to the two ports on the hydraulic pressure source side of the electromagnetic switching valve 5, and the other two ports on the fluid chamber 3 side are separate (for example, of the vehicle body 1). It is connected to the oil passage 3m of the fluid chamber 3 (on the left and right sides) and the gas spring 9 by the pipe lines 12, 12.

6 is a vehicle height control means for changing the upper limit value and the lower limit value of the vehicle height target value and controlling the switching of the electromagnetic switching valve 5 to control the vehicle height adjustment. 8 is a logic circuit,
The output signal from the vehicle speed detection means 15 for detecting the vehicle speed and the output signal from the opening / closing body opening / closing detection means 7 for detecting the opening / closing of the openable / closable body provided on the vehicle body 1 are received, and the vehicle is output according to the output signal. The upper limit value and the lower limit value of the vehicle height target value set by the high control means 6 are changed.

As shown in FIGS. 2 and 3, in each of the fluid chambers 3, a piston 3b is loosely fitted in a cylinder 3a, and the piston 3
b is fixed to the lower end of the piston rod 3c having a considerably large diameter. Further, the upper end of the piston rod 3c is made to penetrate the upper end of the cylinder 3a, and the seal 3
d is provided. Further, a stopper 3e is fixedly provided in the middle of the piston rod 3c to restrict the expansion change of the liquid chamber 3 to a certain amount or less. The piston 3b is provided with a one-way valve 3f that allows an upward flow and another one-way valve 3g that allows a downward flow.

The one-way valves 3f and 3g are provided with a tongue piece 3i that opens and closes the oil passage 3h penetrating the piston 3b, but may be one-way valves having other well-known configurations.

The lower end 3j of the cylinder 3a is attached to the bearing casing 2b of the axle 2 (see FIG. 1), while the upper end 3k of the piston rod 3c is mounted on the vehicle body 1 by the mount rubber 1
It is attached via b. Furthermore, the bracket 1a
The lower side of the cylinder 3 is when the liquid chamber 3 contracts and changes.
A stopper 1c for a is provided.

An oil passage 3m is formed through the piston rod 3c in the axial direction, and a gas spring 9 is linked to the oil passage 3m.
In the gas spring 9, an upper hemispherical shell 9a and a lower hemispherical shell 9b are hermetically integrated via an O-ring 9c. An elastic wall 9e is attached to the lower hemispherical shell 9b by a stopper 9d, and the inside of the gas spring 9 is vertically and airtightly partitioned by the elastic wall 9e. In addition, a cap 9f for preventing adhesion is provided below the center of the elastic wall 9e. Further, the inside of the gas spring 9 is filled with gas above the elastic wall 9e, and below the elastic wall 9e, the inside of the lower hemispherical shell 9b communicates with the oil passage 3m of the fluid chamber 3. Due to this, the hydraulic oil is filled and is configured to function as an accumulator.

As the opening / closing body opening / closing detection means 7, a trunk opening detection means 7a for detecting opening / closing of a trunk lid (not shown) for opening / closing the trunk room, and a fuel for detecting opening / closing of a fuel cap (not shown) for opening / closing the inlet of the fuel tank. It is provided with an opening detection means 7b and a door opening detection means 7c for detecting opening / closing of a door (not shown). The trunk lid, fuel cap, and door are all body 1
Each of the means 7a to 7c is configured to output a "1" level signal when they are "open" and a "0" level signal when they are "closed". ing.

The vehicle speed detecting means 15 detects the vehicle speed V = 0 and outputs a signal of "1" level, and outputs a signal of "0" level when V ≠ 0.

As shown in FIG. 3, the logic circuit 8 includes an OR circuit 8a and an AND circuit 8b. The OR circuit 8a is linked to the trunk open detecting means 7a, the fuel open detecting means 7b and the door open detecting means 7c, and the output of the OR circuit 8a is input to one terminal of the AND circuit 8b. The output of the vehicle speed detecting means 15 is input to the other terminal of the AND circuit 8b.

The vehicle height control means 6 is directly linked to a vehicle height sensor 13 for detecting the current vehicle height X, and also has a target vehicle height level X.
Target vehicle height level output means 1 for outputting a signal corresponding to 0
4 is a target level width setting means 6a capable of changing the upper limit value and the lower limit value with respect to the target vehicle height level X0 (target vehicle height value).
(Upper limit value / lower limit value changing means).

The target level width setting means 6a includes a narrow lower limit value output means 6b,
A wide lower limit value output means 6c, a narrow upper limit value output means 6d, and a wide upper limit value output means 6e are provided, and the outputs from the target vehicle height level output means 14 are input to the respective means 6b to 6e. .

If the upper and lower limits of the target vehicle height level are narrow, half the width is α1, and if the upper and lower limits are wide, half the width is α2. For example, the output signal of the narrow lower limit value output means 6d is "X0 -α1", the output signal of the narrow upper limit value output means 6d is "X0 + α1", and the output signal of the wide lower limit value output means 6c is "X0 -α2" and wide. The output signal of the upper limit value output means 6e is configured to have a value representing "X0 + α2". The above value α1
Is set to a value smaller than the value α2, and the value of 2α1 (that is, the value of the narrow vehicle height level width) is set as an appropriate dead zone width when the vehicle height is automatically controlled during normal driving. On the other hand, the value of 2α2 (that is, the value of the wide vehicle height level width) is set as the width of the dead zone such that the vehicle height adjustment is hardly executed when it is desired to eliminate the frequent vehicle height adjustment.

The target level width setting means 6a is further provided with a changeover switch 6f configured as a double pole double throw, and as shown in FIG. 3, a "1" level signal from the AND circuit 8b is inputted to its solenoid 6g. As a result, the initial state shown by the solid line in FIG. 3 is switched to the state shown by the broken line.

Further, the vehicle height control means 6 receives the signal from the vehicle height sensor 13 and the signal switched by the changeover switch 6f.
An up-side differential amplifier 6h and a down-side differential amplifier 6i are provided.

The output signal from the changeover switch 6f is supplied to the plus side input terminal of the raising side differential amplifier 6h and the minus side input terminal of the lower side differential amplifier 6i, and the minus side input terminal of the raising side differential amplifier 6h and The output signals of the vehicle height sensor 13 are input to the positive input terminals of the lower differential amplifier 6i. Also. The raising side differential amplifier 6h and the lowering side differential amplifier 6i are respectively connected to the raising side solenoid 5a and the lowering side solenoid 5b of the electromagnetic switching valve 5 via the raising side power amplifier 6j and the lowering side power amplifier 6h. .

With the above configuration, when the trunk lid, the fuel cap and the door of the vehicle body 1 are respectively closed, the trunk open detecting means 7a, the fuel open detecting means 7b and the door open detecting means 7c are all at the "0" level. The OR circuit 8 to which these signals are input.
As is well known, a outputs a "1" level signal.

On the other hand, when the vehicle is running, the vehicle speed detecting means 15 outputs a signal of "0" level, and therefore the AND circuit 8b outputs a signal of "0" level. Therefore, the changeover switch 6f remains in the initial state shown by the solid line in FIG. 3, the signal corresponding to "X0-α1" is input to the plus side input terminal of the raising side differential amplifier 6h, and the minus side input terminal is inputted. Is an "X"
A signal corresponding to is input. As a result, the raising differential amplifier 6h outputs a signal corresponding to "X0-α1-X".

Further, a signal corresponding to "X" is input to the positive side input terminal of the lower side differential amplifier 6i, and a signal corresponding to "X0 + α1" is input to the negative side input terminal. As a result, the lower-side differential amplifier 6i operates as "X-
A signal corresponding to (X0 + α1) "is output.

When X <X0-α1, a signal of "1" level is output from the raising side differential amplifier 6h, and naturally, X
Since <X0 + α1, a "0" level signal is output from the lower differential amplifier 6i. The "1" level signal from the raising side differential amplifier 6h becomes a raising command signal,
It is input to the raising side power amplifier 6j, and the raising side solenoid 5a is excited by the output, and the solenoid switching valve 5
Is raised (upper side in FIG. 1, left side in FIG. 2)
Is switched to. In response to this, the hydraulic oil discharged from the hydraulic pump 4 passes through the discharge side pipe line 10 → the electromagnetic switching valve 5 → the pipe line 12 → the oil line 3 m → the lower oil chamber inside the cylinder 3 a → the one-way valve 3 f. To send by pressure. At this time, the same hydraulic oil pressure acts on the upper and lower oil chambers of the piston 3b, but the area on the lower oil chamber side is larger, so that the piston 3b faces upward in FIG. Is exerted, the liquid chamber 3 expands and hydraulic oil flows into the increasing internal volume. Thus, the vehicle body 1 is lifted and the vehicle height X becomes large.

If X0 + α1>X> X0-α1, the rising side differential amplifier 6h and the lower side differential amplifier 6i do not output a "1" level signal, and therefore the raising side solenoid 5a and the lower side solenoid 5a. 5b are operated together, the electromagnetic switching valve 5 is in the neutral position shown in FIG. 2, there is no inflow / outflow of the hydraulic oil in the liquid chamber 3, and the value of the vehicle height X is maintained constant.

Contrary to the above case, when X> X0 + α1, as is apparent from the above description, the down side differential amplifier 6i outputs the down command signal of "1" level, and The side solenoid 5b operates, and the solenoid switching valve 5
It is switched to the lower side (lower side in FIG. 1, right side in FIG. 2). Therefore, the fluid chamber 3 is contracted by the weight of the vehicle body 1 and the volume of the fluid chamber 3 is reduced so that the hydraulic oil is returned to the oil tank 4b through the return pipe 11.

Then, as in the case described above, X0 + α1>X> X0
When it becomes −α1, the control of vehicle height adjustment is stopped.

Next, considering the case of traveling with the trunk lid open, at this time, the trunk open detection means 7a outputs "1".
The level signal is output, and the OR circuit 8a also outputs the "1" level signal, but the vehicle speed detecting means 15 outputs the "0" level signal, so that it is eventually output from the AND circuit 8b. The signal of "0" level remains as it is, and it operates in the same manner as in the case described above.

However, if the vehicle (body 1) is in a stopped state and any of the opening / closing bodies (trunk lid, fuel cap, door) is open, one of the opening / closing body opening / closing detection means 7 indicates the level of “1”. A signal is output and the OR circuit 8
Both a and the output of the vehicle speed detection means 15 become a "1" level signal. Therefore, the output of the AND circuit 8b becomes the "1" level, the solenoid 6g is excited, and the changeover switch 6f switches to the state shown by the broken line in FIG. In this case, the positive side input terminal of the rising side differential amplifier 6h and the negative side input terminal of the lower side differential amplifier 6i have "X0-
Signals corresponding to "α2" and "X0 + α2" are input.
As described above, since α2> α1, X0 + α2>
The width of the target vehicle height level X where X> X0 -α2 is larger than the width of the target vehicle height level X where X2 + α1>X> X0 -α1 in the case described above.

In this way, the changeover switch 6f is changed over to the third
In the state shown by the broken line in the figure, the width of the dead zone of the vehicle height control by the vehicle height control means 6 becomes considerably large, and the vehicle height control is hardly performed.

The embodiment of the present invention is not limited to the above-described range, and the width of the target vehicle height level may be made wider when the opening / closing body is opened than when the opening / closing body is closed. It is not necessary to change both the upper limit value and the lower limit value of the target value, and it suffices to perform either one of upward correction of the upper limit value and downward correction of the lower limit value. The output signal of the means may be set to "1" level and "0" level opposite to those in the above-mentioned embodiment, and the logic circuit may be configured to have another structure that performs the same function, and various modifications are possible. is there.

(Effects of the Invention) As described above, the present invention, when the opening / closing body is opened to, for example, carry in / out luggage, refuel, or get on / off passengers, the upper limit of the vehicle height target value is not exceeded. The target vehicle height value is wider when the opening / closing body is opened than when the opening / closing body is closed. The adjustment is limited, so that the vehicle height is not frequently adjusted and the vehicle body does not move up and down, and it is possible to eliminate the discomfort caused by noise and the like.

[Brief description of drawings]

1 to 3 show one embodiment of the present invention, FIG. 1 is an overall view including a partial longitudinal sectional view, hydraulic line diagram and block diagram, and FIG. 2 is a main part including hydraulic line diagram. A longitudinal sectional view and FIG. 3 are block diagrams. 1 ... Vehicle body, 2 ... Axle, 3 ... Fluid chamber, 6 ... Vehicle height control means, 6a ... Target level width setting means (upper limit value / lower limit value changing means), 7 ... Opening / closing body opening / closing detection means , 7a ... Trunk open detection means, 7b ... Fuel open detection means, 7
c ... Door open detection means, 8 ... Logic circuit, 13 ... Vehicle height sensor, 14 ... Target vehicle height level output means, 15 ...
Vehicle speed detection means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-75814 (JP, A) JP-A-56-75003 (JP, A) Actual opening Sho-58-126509 (JP, U) Actual opening Sho-59- 16310 (JP, U)

Claims (1)

[Claims] 1. A vehicle height adjusting device for adjusting a vehicle height by providing a variable volume liquid chamber between a vehicle body and an axle, and adjusting a fluid in the fluid chamber to change the volume of the fluid chamber to adjust a vehicle height. The opening / closing body opening / closing detection means for detecting the opening / closing of the opening / closing body, which is openable / closable, and the vehicle height detection means for detecting the vehicle height, and the output from the opening / closing body opening / closing detection means, when the opening / closing body is opened, Upper and lower limits that widen the target vehicle height range when opening and closing the open / close body by performing at least one of upward correction of the upper limit of the high target value and downward correction of the lower limit. The output of the value changing means, the vehicle height detecting means, and the upper limit value / lower limit value changing means is received, and only when the current vehicle height is larger than the upper limit value of the target vehicle height value or smaller than the lower limit value thereof, Vehicle height control that adjusts the fluid and adjusts the vehicle height by changing the volume of the fluid chamber And a vehicle height adjusting device.