JPS5981211A - Air suspension device - Google Patents

Abstract

PURPOSE:To make the level control of a car attainable in a smooth manner, by turning round a lever setting shaft with the motion of a control lever for a leveling valve, opening or closing both valve suction and exhaust ports, while making a device so as to perform suction and exhaust of air inside an air spring. CONSTITUTION:When large load is imposed on a car body whereby a frame 1 is sunk down to an axle 6, a control lever 4 is turned round upward as shown in a chain line and turns round a rocker (unillustrated herein) of a leveling valve 2 via a shaft 3, making a sleeve move sidewise and opening a suction valve, and air is fed to the suction valve, thus a car level is raised high. On the contrary, when the car level grows large, the sleeve moves reversely, opening an exhaust valve, and thereby the air inside an air spring 7 is exhausted. With this constitution, the level control of a car can be adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air suspension device in which an axle is suspended on a vehicle body via an air spring.

Air suspension systems that use air springs as chassis springs have a small spring constant and are more effective at isolating vibrations than other suspension systems, and are therefore widely used in vehicles where riding comfort is important. . The air springs such as air bellows that make up the air suspension device are usually connected to an air tank via a leveling valve, and the leveling valve supplies compressed air from the air tank to the air spring, or inside the air spring. It is designed to discharge compressed air.

In other words, the leveling valve detects the vehicle height and, in accordance with this detection, supplies air into the air spring or discharges air from the air spring, thereby maintaining the vehicle height at a nearly constant height. ing. Therefore, even when such an air suspension device is applied to a truck, etc., the loading platform will be held at a constant height by the leveling valve, which will result in poor cargo handling efficiency when loading and unloading cargo. This results in the disadvantage of becoming.

The present invention has been made in view of these problems, and an object of the present invention is to provide an air suspension device that allows the vehicle height to be arbitrarily adjusted! The target is

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings according to an illustrated embodiment. As shown in FIGS. 1 and 2, a leveling valve 2 is fixed to a frame 1 constituting the body of an automobile. This leveling valve 2 has its shaft 3
A control lever 4 is attached to the control lever 4.
is connected to an axle 6 via a link 5.

As shown in FIG. 2, the axle 6 is suspended from the frame 1 via an air spring 7 such as an air bellows.

The leveling valve 2 is equipped with a motor 8 for forcibly rotating its shaft 3 relative to the control lever 4, and a gear 9 fixed to the output shaft of the motor 8
It meshes with a gear 10 fixed to the shaft 3. The motor 8 is driven by a drive circuit 11. Further, a control signal is supplied to the drive circuit 11 from a controller 12.

Furthermore, the detection output of a position detection sensor 13 that detects the position of the control lever 4 is inputted to the drive circuit 11.

Next, the specific structure of the leveling valve 2 will be explained with reference to FIG. 3. The leveling valve 2 includes a casing 14, and openings on both sides of the casing 14 are closed by caps 15. A rod 16 is held by a pair of left and right caps 15, and a pair of sleeves 17, 18 are slidably fitted onto the rod 16. The sleeves 17, 18 are each biased toward each other by a compression coil spring 19. and the above pair of sleeves 17.18
The lower end portion of the rocker 20 is held between the tip portions of the rocker 20 . The rocker 20 is fixed to the shaft 3. Furthermore, an arm 21 is rotatably supported by this shaft 3.

The leveling valve 2 includes a cylinder 22 at the bottom of the casing 14, and an eye piston 23 is disposed within the cylinder 22. Bi3ton 23 has cylinder 22
Inside, it can be slid left and right in FIG. A through hole 24 is formed approximately in the center of the screw 1 23, and the tip of the arm 21 is received in the through hole 24. Further, an intake boat 25 is provided on the right side of the cylinder 22, and an intake valve 26q is attached to the fourth intake boat 25. Also, the above intake port? 5 is connected to an air tank (not shown). A connection port 27 is provided on the left side of the cylinder 22 in FIG. 3, and the valve 2 is connected to the air sling 7 through this port 27. The connection boat 27 also has
An exhaust valve 28 is attached, and this exhaust valve 2
The rear side of the exhaust port 8 has a 29-inch exhaust port. Further, the intake boat 25 and the connecting port 27 are connected by an air supply path 30.

With the above structure, the normal vehicle height adjustment operation of the leveling valve 2 will be explained with reference to FIGS. 2 and 3. When a large load is applied to the vehicle body, or when the air in the air spring 7 decreases, this causes the frame 1 to move downward relative to the axle 6. Then, the control lever 4μ, which is connected to the axle 6 via the link 5, is rotated upward as shown by the chain line in FIG. When the control lever 4 is rotated upward, the rotational movement of the lever 4 is transmitted to the lock 7-20 via the shaft 3, and the rocker 20 also rotates counterclockwise in FIG. 3 about the axis of the shaft 3. It will be rotated. Then, the lower end of the rocker 20 is connected to the pair of sleeves 1
The right sleeve 18 of 7.18 is pushed to the right, so that the sleeve 17 is also pushed to the right by the coil spring 19. Then, the arm 21 held between these sleeves 17 and 18 is also rotated counterclockwise around the shaft 3, and the piston 23
is moved to the right within the cylinder 22. As a result, the piston 23 opens the intake valve 26 and passes through the air supply path 30 from the intake port 25 to the connection port 27.
This will cause air to flow through. Therefore, the compressed air in the air tank is supplied into the air spring 7 through the air supply path 30 and the connection port 27 of the leveling valve 2, and the air spring 7 is expanded. When the air spring 7 expands to a predetermined height, the control lever 4 is moved back to the horizontal position, so the arm 21 also returns to the neutral position, the intake valve 26 is closed, and the air is discharged from the air tank to the air spring 7. supply will be stopped.

Next, when the load applied to the vehicle body decreases, the air spring 7 expands and the frame 1 is pushed up. In other words, the vehicle height becomes higher. The control lever 4 is then rotated downward as shown by the chain line in FIG. This downward rotation of the lever 4 is transmitted to the rocker 20 via the shaft 3, and the rocker 20 is rotated clockwise about the shaft 3 in FIG. The clockwise rotation of the rocker 20 will be transmitted via the pair of sleeves 17, 18 to the arm 21, which in turn will move the piston 23 to the left. When the piston 23 moves to the left, the piston 23 opens the exhaust valve 28, and the air in the air tank 7 flows through the connection port 27 and the exhaust port 2.
9 and is discharged to the outside. That is, when the vehicle height increases, the air in the air spring 7 is discharged by the leveling valve 2, thereby lowering the frame 1 so that the vehicle height is at a predetermined position.

Next, the operation of artificially lowering the vehicle height by forcibly rotating the shaft 3 relative to the control lever 4 by the motor 8 will be explained with reference to FIGS. 4 and 5. Note that this operation is performed to facilitate loading and unloading of cargo by lowering the platform of a truck equipped with the air suspension device according to the present embodiment, for example. As shown in FIG. 4, the amount of air in the air spring 7 is maintained at a predetermined value by the leveling valve 2, and the height of the frame 2 is thereby maintained at a constant value. When the controller 12 (see FIG. 1) is operated, a control signal from the controller 12 is supplied to the drive circuit 11, and the motor 8 is driven to rotate based on the output of the drive circuit 11. . The rotation of the motor 8 is then controlled by the shaft 3 through gears 9 and 10.
This causes the shaft 3 to rotate clockwise as shown in FIG. Note that the rotation angle of the shaft 3 at this time is proportional to the value instructed by the controller 12. When the shaft 3 rotates, the rocker 20 fixed to the shaft 3 also rotates in the same direction.
The sleeve 17 will be pushed to the left. Therefore, the sleeve 18 is pushed to the left by the compression coil spring 19,
For this purpose, the arm 21 is attached to the shaft 3 as shown in FIG.
It will be rotated in the time direction around the center.

At this time, the control lever 4 is connected to the axle 6 via the link 5.
The shaft 3 cannot be rotated because it is connected to the control lever 4, and therefore the shaft 3 is forced to rotate relative to the control lever 4. Note that the shaft 3 for this control lever 4
In order to allow relative rotation of the control lever 4, the control lever 4 is coupled to the shaft 3 through a friction clutch, so that the shaft 3 is forcibly rotated with respect to the control lever 4, as shown in FIG. In this case, the friction clutch will slip.

When the shaft 3 is forcibly rotated with respect to the control lever 4 and the arm 21 is rotated clockwise as shown in FIG. 5, the arm 21 moves the piston 23 into the cylinder 2.
This piston 2 is moved to the left within the piston 2.
3 will push the exhaust valve 28 to open it. The air in the air spring 7 will therefore be exhausted through the connecting bow 1 27 and the exhaust port 29.

In this way, the air in the air spring 7 gradually decreases, and as a result, the frame 1 gradually descends, lowering the vehicle height as shown in FIG. When the vehicle height becomes lower, as is clear from FIG. 6, the distance between the frame 1 and the axle 6 becomes closer, so that the control lever 4 connected to the axle 6 via the link 5 moves counterclockwise. direction, that is, upward. When the control lever 4 rotates upward, the shaft 3 connected to the lever 4 through a friction clutch (not shown) also rotates in the direction of the half-hour hand, as shown in FIG. , the rocker 20 fixed to the shaft 3 changes to a vertical position. When the rocker 20 is rotated to the vertical angle, the pair of sleeves 17.18 are returned to the intermediate position, so that the arm 21 clamped between the sleeves 17.18 also assumes a vertical position. , it will rotate counterclockwise. As a result, the piston 23 moves back and returns to the neutral position, and the suppression of the exhaust valve 28 by the piston 23 is also released. Therefore, the exhaust valve 28 closes, and the air exhaust ends with the air spring 7 contracted as shown in FIG.

Note that the vehicle height at this time, that is, the height of the frame 1 is the first
□ is detected by the position detection sensor 13 shown in the figure, and this output is supplied to the drive circuit 11, where it is compared with the control signal from the controller 12, and the vehicle height is determined by the controller 12. A check will be made to see if the height is the same as the specified height. If the height instructed by the controller 12 and the height of the frame 1 are different, the height of the frame 1 is corrected by the motor 8.

As described above, according to the air suspension device of this embodiment, the air in the air spring 7 is forcibly rotated by the motor 8 with respect to the control lever 4 based on instructions from the controller 12. This makes it possible to lower the vehicle height at will. Therefore, by lowering the loading platform of a truck equipped with this air suspension device and making it easier to load and unload cargo, it is possible to rationalize cargo handling. When the loading and unloading work is completed, the shaft 3 is forcibly rotated by the motor 8 relative to the control lever 4 in the opposite direction to the above operation, that is, in the counterclockwise direction, as shown in FIG. The intake valve 26 shown in FIG. 3 is opened, compressed air is supplied from the air tank to the air spring 7, and as a result, the leveling valve 2 returns to its normal state as shown in FIG. Therefore, it is possible to carry out normal driving in this state.

Although the present invention has been described above with reference to the illustrated embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made based on the technical idea of the present invention. For example, although the above embodiment relates to an air suspension device for a truck, the present invention is applicable to various types of vehicles other than trucks. Furthermore, by applying the present invention to the respective axles of the front wheels and rear wheels, it becomes possible to adjust the height of the vehicle body in a horizontal state as a whole. By applying the present invention to only one axis of the vehicle, it is possible to arbitrarily change the number of driven wheels.As described above, the present invention transmits the movement of the control lever of the leveling valve to this valve. By forcibly rotating the shaft relative to the control lever, the air in the air spring can be exhausted through the exhaust boat of the leveling valve, so the normal vehicle height adjustment operation of the leveling valve is This makes it possible to reduce the amount of air in the air spring without interfering with the engine speed, thereby shortening the distance between the vehicle body and the axle.

So, for example, by applying this to a track,
It becomes possible to lower the loading platform and streamline cargo handling.・

[Brief explanation of the drawing]

□ Fig. 1 is a block diagram of an air suspension device according to an embodiment of the present invention, Fig. 2 is a side view of main parts showing the normal vehicle height adjustment operation of the air suspension device, and Fig. 3 is a block diagram of the air suspension device according to an embodiment of the present invention. Vertical sectional view of the leveling valve that performs adjustment, No. 4
The figure is a side view of the air suspension device showing the operation of forcibly rotating the shaft of the leveling valve relative to the control lever, and Figure 5 is a longitudinal cross-section of the same leveling valve.
FIG. 6 is a side view of essential parts of the air suspension device in a state where air is discharged from the air spring, and FIG. 7 is a longitudinal sectional view of the leveling valve in this state. In addition, in the symbols used in the drawings, 1...Frame 2...Leveling valve 3...Shaft 4...Control lever 6...Axle 7...・Air spring 8...Motor 9.10...Gear. Applicant Hino Motors Co., Ltd.

Claims (1)

[Claims] In a device in which the axle is suspended on the vehicle body via an air spring, and a leveling valve is connected between the air spring and the air tank to adjust the vehicle height, the movement of the control lever of the leveling valve is controlled by the control lever of the leveling valve. means for forcibly rotating a shaft that transmits transmission to the control lever relative to the control lever, and by forcibly rotating the shaft by the rotating means, air in the air spring is discharged through an exhaust port of the leveling valve. An air suspension device characterized by: