JP3963627B2 - Air suspension vehicle height adjustment device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle height adjusting device suitable for an air suspension vehicle, particularly a truck having a luggage compartment formed at a rear portion thereof.
[0002]
[Prior art]
Conventionally, left and right air springs arranged between a chassis frame and left and right wheels support the chassis frame, and these air springs are connected to the air tank via a leveling device that opens and closes according to the height of the chassis frame with respect to the wheels. Connected air suspension vehicles are known. In this air suspension vehicle, the on-spring resonance point can be set low and fine vibrations can be absorbed as compared with a method in which the chassis frame is supported by a metal spring, so that the ride comfort of the occupant can be improved. In such an air suspension vehicle, since the air spring and the air tank are connected via a leveling device, in a vehicle such as a truck, a load is loaded in the rear luggage compartment, and the height of the chassis frame with respect to the wheels changes. However, the leveling device opens and closes according to the height, and the high-pressure air in the air tank is supplied into the air spring, so that the height of the chassis frame relative to the wheels is always kept constant regardless of the load state. ing.
[0003]
[Problems to be solved by the invention]
However, since conventional air suspension vehicles maintain a constant height regardless of the load state of the load, the vehicle height remains constant even when, for example, the load is shifted to the left or right of the luggage compartment. Be drunk. For this reason, the driver of the truck has a problem of knowing the fact that the load is offset and loaded for the first time due to the difference in handling stability when rolling the vehicle in the right or left direction. This can be solved by evenly loading the packages on the left and right, but some packages cannot be loaded uniformly. In order to drive the vehicle according to the load state of the load, it may be necessary for the driver to check the load state of the load before driving the vehicle. In some cases, the loading state cannot be confirmed at a glance. In particular, when the person who loads the luggage is different from the person who drives the vehicle, it is desired that the driver can grasp the loaded state of the luggage by looking at the outside of the vehicle. An object of the present invention is to provide a vehicle height adjusting device for an air suspension vehicle that can grasp a loaded state of a load at a glance from the outside of the vehicle.
[0004]
[Means for Solving the Problems]
As shown in FIGS. 1 and 2, the invention according to claim 1 includes left and right air springs 17 and 18 that are respectively provided between the left and right wheels 12 and 12 and the chassis frame 16, and support the chassis frame 16. A vehicle height adjustment valve 32 provided in an air conduit 31 connecting the left and right air springs 17 and 18 and the air tank 29 and supplying and discharging compressed air in the air tank 29 to the left and right air springs 17 and 18, respectively, and the chassis frame 16 The left and right vehicle height sensors 33 and 35 are respectively provided between the left and right wheels 12 and 12 to electrically detect the left and right vehicle heights, and the left and right vehicle height sensors 33 and 35 detect the left and right vehicle height sensors 33 and 35. And a controller 34 for controlling the vehicle height adjusting valve 32 so that the average value becomes a predetermined reference value. The controller 34 detects the left and right vehicle height sensors 33, 35. Air left and right when the slope by calculating a tilt to the right or left of the chassis frame 16 based on the force of more than predetermined inclination value consisting of one of the values until 2.5 degrees 1.5 degrees Compressed air is supplied to or discharged from either or both of the springs 17 and 18 to control the vehicle height adjustment valve 32 so that the inclination is maintained at a predetermined inclination value, and the controller 34 averages the left and right vehicle heights. The vehicle height adjustment of the air suspension vehicle is characterized in that the control of the vehicle height adjustment valve 32 is stopped when the vehicle is at a predetermined reference value and the right or left inclination of the chassis frame 16 becomes the predetermined inclination value. Device.
[0005]
In the vehicle height adjusting device of the air suspension vehicle according to the first aspect, when the load is deviated and loaded and the vehicle is tilted to the right or left, the controller 34 is based on the detection outputs of the left and right vehicle height sensors 33 and 35. The slope is calculated. When this inclination is equal to or greater than a predetermined inclination value, the controller 34 switches the vehicle height adjustment valve 32 to supply or discharge compressed air to one or both of the left and right air springs 17 and 18, and to adjust the inclination. When the predetermined inclination value is reached, the supply of compressed air is stopped. The driver recognizes the fact that the vehicle is leaning in the tilt direction by visually recognizing the vehicle tilted at a predetermined tilt value from the outside.
[0006]
Then , when the predetermined inclination value is any value between 1.5 degrees and 2.5 degrees, the inclination of the vehicle can be reliably recognized. If the predetermined inclination value is less than 1.5 degrees, it is difficult to confirm the presence or absence of the inclination from the outside of the vehicle, and if the predetermined inclination value exceeds 2.5 degrees, the steering stability during vehicle traveling is reduced. descend.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a truck 10 that is an air suspension vehicle is provided with front wheels 11 and 11 and rear wheels 12 and 12 that are wheels on the left and right, respectively. The left and right front wheels 11, 11 are rotatably attached to both ends of a front axle (not shown) extending in the vehicle width direction, and the left and right rear wheels 12, 12 are fixed to both ends of a rear axle 13 (FIG. 3) extending in the vehicle width direction. The rear axle 13 is rotatably held by the axle housing 14. The vehicle height adjusting device of the present invention includes left and right air springs 17 and 18 provided between rear wheels 12 and 12 as wheels and a chassis frame 16 (FIGS. 2 and 3), respectively.
[0008]
As shown in FIG. 2, the left and right air springs 17 and 18 support the chassis frame 16, and the chassis frame 16 includes a pair of side frames 16 a and 16 b extending in the traveling direction of the track 10. First and second air springs 17a and 17b, which are left air springs 17, are disposed on the left side frame 16a before and after the axle housing 14 that holds the axle 13 (FIG. 3). Third and fourth air springs 18a and 18b, which are right air springs 18, are disposed on the frame 16b. These air springs 17a, 17b, 18a, 18b are provided with a pair of suspension beams 19a, 19b. The left suspension beam 19a has a front end bonded to the first air spring 17a and a rear end bonded to the second air spring 17b. The right suspension beam 19b has a front end bonded to the third air spring 18a and a rear end bonded to the fourth air spring 18b. Both ends of the axle housing 14 are respectively attached to the longitudinal center of the suspension beams 19a and 19b, and the axle housing 14 is installed on the pair of suspension beams 19a and 19b.
[0009]
A pair of radius rods 21 and 21 are attached between the axle housing 14 and the pair of side frames 16a and 16b, and a stabilizer 22 is provided between the pair of side frames 16a and 16b and the pair of suspension beams 19a and 19b. Provided. The stabilizer 22 is formed by fixing the proximal ends of stabilizer arms 22b and 22c to both ends of a stabilizer bar 22a extending in the vehicle width direction, and the distal ends of the stabilizer arms 22b and 22c are attached to a pair of suspension beams 19a and 19b. The radius rods 21 and 21 and the stabilizer arms 22b and 22c serve as tension bars or pull-back bars between the axle housing 14 and the pair of side frames 16a and 16b.
[0010]
As shown in FIG. 1, the vehicle height adjusting device is provided on the left and right air springs 17, 18 and the air pipe 31 connecting the left and right air springs 17, 18 and the air tank 29. A single vehicle height adjusting valve 32 for supplying and discharging compressed air in the air tank 29, left and right vehicle height sensors 33, 35 for electrically detecting left and right vehicle heights, and left and right vehicle height sensors 33, And a controller 34 for controlling the vehicle height adjustment valve 32 based on the respective detection outputs 35. The vehicle height adjustment valve 32 is a four-port solenoid valve having two control inputs 32a and 32a. The valve 32 has a single first port 32b connected to the air tank 29, two second ports 32c and 32c connected to the left and right air springs 17 and 18, respectively, and a single discharge opened to the atmosphere. Port 32d.
[0011]
The left and right vehicle height sensors 33 and 35 are respectively provided between the chassis frame 16 (FIG. 2) and the left and right wheels 12 and 12, and the left and right vehicle height sensors 33 and 35 in this embodiment are non-contact types, respectively. A potentiometer, the same one is used. The left vehicle height sensor 33 will be described as a representative. As shown in detail in FIG. 3, a sensor main body 33a attached to the left side frame 16a, a lever 33b whose base end is pivotally attached to the sensor main body 33a, and an upper end Has a link 33c pivotally supported at the tip of the lever 33b and having a lower end connected to the axle housing 14. The vehicle height sensor 33 electrically detects that the vehicle height is lower than the reference value when the tip of the lever 33b is obliquely upward, and electrically indicates that the vehicle height is high when it is obliquely downward. To detect.
[0012]
Returning to FIG. 1, the detection outputs of the left and right vehicle height sensors 33, 35 are connected to the control input of the controller 34, and the control output of the controller 34 is connected to the two control inputs 32 a, 32 a of the vehicle height adjustment valve 32. . The memory 39 is provided in the controller 34, the reference value H ₀₁ vehicle height during cargo loading track 10 in the memory 39, a predetermined slope value S ₀₁ for the inclination of the track 10 are respectively stored.
In this embodiment, a truck is used as the air suspension vehicle. However, a passenger car, a bus, or other vehicles may be used.
In this embodiment, one 4-port vehicle height adjustment valve (solenoid valve) having two control inputs is provided. However, a three-port vehicle height adjustment valve (solenoid valve) having a single control input is provided. Two may be provided. In this case, the first ports of the two vehicle height adjusting valves are connected to the air tank, the second port is connected to the left and right air springs, and the discharge port is opened to the atmosphere.
[0013]
The operation of the thus configured vehicle height adjusting device will be described based on the flowchart shown in FIG.
When the driver stops the truck 10 at the luggage storage area and loads the luggage into the luggage room 41 (FIG. 4) or unloads the loaded luggage from the luggage room 41, the load in the luggage room 41 fluctuates and the left and right air The springs 17 and 18 are compressed or extended to raise and lower the vehicle height. When the vehicle height rises and falls, the left and right vehicle height sensors 33 and 35 detect the vehicle height on the left and right sides of the truck. The controller 34 calculates an average value H of the left and right vehicle heights of the vehicle body 15 based on the detection outputs of the left and right vehicle height sensors 33 and 35. That is, assuming that the vehicle height detected by the right vehicle height sensor 35 is RH (FIG. 4) and the vehicle height detected by the left vehicle height sensor 33 is LH (FIG. 4), the controller 34 calculates the average value H of these values. Obtained from H = (RH + LH) / 2. The controller 34 compares the average value H with the vehicle height reference value H ₀₁ stored in the memory 39, and determines that it is necessary to correct the vehicle height when H <H ₀₁ or H> H ₀₁ .
[0014]
Next, the controller 34 calculates the right or left inclination of the chassis frame 16 based on the detection outputs of the left and right vehicle height sensors 33 and 35. That is, if the distance between the left and right vehicle height sensors 33 and 35 is W (FIG. 4), the controller 34 obtains the inclination S of the chassis frame 16 from S = (RH−LH) / W. The controller 34 compares the inclination S with a predetermined inclination value S ₀₁ stored in the memory 39, and determines that the left and right heights of the vehicle 10 are not uniform when the absolute value of S is larger than S ₀₁ , and is less than that. Sometimes it is determined that the left and right heights of the vehicle 10 are uniform.
[0015]
If the load is loaded and the load is evenly loaded in the luggage compartment 41, the left and right air springs are compressed uniformly, so the controller 34 determines that the vehicle height needs to be corrected. The left and right heights of the vehicle 10 are determined to be uniform. In this case, the controller 34 controls the level control valve 32 to supply compressed air at the same time to the left and right air springs 17 and 18, compression to the left and right air springs 17 and 18 when they become H = H ₀₁ Stop supplying air. On the contrary, when the loaded cargo is carried out from the cargo compartment 41, the controller 34 controls the vehicle height adjustment valve 32 to discharge the compressed air from the left and right air springs 17 and 18 simultaneously, so that H = _H01 . The discharge of the compressed air from the left and right air springs 17, 18 is stopped.
[0016]
On the other hand, when the load is deviated and loaded, the controller 34 determines that the vehicle height needs to be corrected, and at the same time determines that the left and right heights of the vehicle 10 are not uniform. In this case, the controller 34 further determines whether the chassis frame 16 is tilted to the left or right. When the chassis frame 16 is tilted to the left as indicated by a two-dot chain line in FIG. 4, the controller 34 judges that fact and controls the vehicle height adjustment valve 32 to supply the compression to the right air spring 18. Supply more compressed air to the left air spring 17 than air, and stop supplying compressed air to the left and right air springs 17 and 18 when the absolute value of S is equal to S ₀₁ and H = H ₀₁ To do. Conversely, if the chassis frame 16 is tilted to the right, the controller 34 determines that and controls the vehicle height adjustment valve 32 so that more compressed air is supplied to the right than the compressed air supplied to the left air spring 17. When the absolute value of S is equal to S ₀₁ and H = H ₀₁ , the supply of compressed air to the left and right air springs 17 and 18 is stopped.
[0017]
As a result, the vehicle height of the truck 10 is always kept constant regardless of the load state of the load, and when the load is deviated and loaded, the track 10 itself is kept tilted at a predetermined inclination value. The For this reason, the driver observes the truck from the outside before getting on the truck 10 and recognizes the fact that the load is deviated in the tilt direction because it is tilted at a predetermined tilt value. Thereafter, the driver gets on the truck 10 and causes the truck 10 to travel according to the loaded state of the baggage that is offset. Here, since the inclination of the truck 10 is a predetermined inclination value that can be visually recognized by the driver, the steering stability during traveling of the vehicle does not deteriorate, and the driver does not feel uncomfortable.
[0018]
【The invention's effect】
As described above, according to the present invention, the left and right air springs provided between the chassis frame and the left and right wheels support the chassis frame, and the vehicle height adjustment valve supplies compressed air to the left and right air springs. Since the left and right vehicle height sensors electrically detect the left and right vehicle heights respectively, for example, when a load is shifted and the vehicle leans to the right or left, the controller The inclination is calculated based on the detected output, and the vehicle height adjusting valve is controlled so that the inclination becomes a predetermined inclination value. That is, when the air spring is excessively inclined to the left, the compressed air is supplied to the left air spring more than necessary. When the air spring is excessively inclined to the right, excessive compressed air is supplied to the right air spring. As a result, the vehicle leans to a predetermined inclination value that does not hinder driving, so the driver recognizes the fact that the load is loaded side by side in the direction of the load, and according to the loaded state of the loaded load. Can drive the vehicle.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an air circuit and an electric circuit of a vehicle height adjustment device for an air suspension vehicle according to an embodiment of the present invention.
FIG. 2 is a plan view showing the air suspension.
FIG. 3 is a left side view showing the air suspension.
FIG. 4 is a rear view of the vehicle.
FIG. 5 is a control flowchart of the apparatus.
[Explanation of symbols]
10 trucks (air suspension vehicles)
12 Rear wheels
16 Chassis Frame 17 Left Air Spring 18 Right Air Spring 29 Air Tank 31 Air Pipe 32 Vehicle Height Adjustment Valve 33 Left Vehicle Height Sensor 34 Controller 35 Right Vehicle Height Sensor

Claims (1)

Left and right air springs (17, 18) provided between the left and right wheels (12, 12) and the chassis frame (16), respectively, for supporting the chassis frame (16);
Compressed air in the air tank (29) is provided to the left and right air springs (17, 18) provided in an air pipe (31) connecting the left and right air springs (17, 18) and an air tank (29), respectively. Vehicle height adjustment valve (32) to supply and discharge;
Left and right vehicle height sensors (33, 35) provided between the chassis frame (16) and the left and right wheels (12, 12), respectively, for electrically detecting left and right vehicle heights,
A controller (34) for controlling the vehicle height adjustment valve (32) so that an average value of the left and right vehicle heights detected by the left and right vehicle height sensors (33, 35) is a predetermined reference value;
The controller (34) calculates the right or left inclination of the chassis frame (16) based on the detection output of the left and right vehicle height sensors (33, 35), and the inclination is 1.5 to 2. Supplying or discharging compressed air to one or both of the left and right air springs (17, 18) when the inclination value is equal to or greater than a predetermined inclination value of any value up to 5 degrees, the vehicle controls the high control valve (32) so as to maintain the slope value,
The controller (34) adjusts the vehicle height when the average value of the left and right vehicle heights becomes a predetermined reference value and the right or left inclination of the chassis frame (16) becomes the predetermined inclination value. A vehicle height adjustment device for an air suspension vehicle, characterized in that control of the valve (32) is stopped .

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