JP2663053B2 - Leveling valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leveling valve, and more particularly to a leveling valve connected between an air source and an air spring.
The present invention relates to a leveling valve that controls the supply and exhaust of air to and from an air spring to maintain the vehicle height at a substantially constant height.

[0002]

2. Description of the Related Art Air springs are used in vehicles such as buses instead of leaf springs or coil springs as suspension springs for suspending the axle of an automobile on a frame. The air spring is usually connected to the air tank via a leveling valve. The leveling valve controls the supply and exhaust of air to and from the air spring according to the load on the vehicle body, so that the vehicle height can be kept almost constant. I try to keep it.

[0003] It is preferable that the height of a bus be reduced when passengers move up and down. In addition, when loading and unloading luggage to and from the platform with a truck or the like, it is convenient if the loading platform can be adjusted to the same level as the platform.
In addition, when entering a garage with a low roof, it is necessary to lower the vehicle height. That is, there is a demand for a function of keeping the vehicle height at a constant level and adjusting the vehicle height to an arbitrary height as needed from the outside.

In response to such a demand, Japanese Utility Model Application
In Japanese Patent No. 50708, a plurality of solenoid valves are provided in parallel with a leveling valve, and these solenoid valves are selectively driven to increase or decrease the air amount of an air spring so that the vehicle height can be arbitrarily adjusted from the outside. A device has been proposed.

In Japanese Utility Model Laid-Open No. 60-72712,
There is disclosed an apparatus in which a link that connects a lever of a leveling valve and an axle is provided with an expansion / contraction mechanism, and this expansion / contraction mechanism is expanded / contracted by an electric motor or the like, and the height of the vehicle is raised and lowered consciously using the function of the leveling valve. Have been.

[0006]

In a vehicle in which a plurality of solenoid valves are provided in addition to the leveling valve and the height of the vehicle can be changed to an arbitrary height by switching these solenoid valves, the function of the leveling valve is interrupted. In addition, since the vehicle height must be adjusted, the number of solenoid valves to be used is increased, which not only increases the cost but also increases the probability of failure. In addition, there is a disadvantage that maintenance and inspection are troublesome.

When a telescopic mechanism having an electric motor is attached to a link connecting a lever of a leveling valve and an axle, this portion not only has a large space but also increases in weight, and the link is constantly running during traveling. Due to the vibration, the load also increases on the mounting portion and the like, and the durability is concerned.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and a leveling valve capable of arbitrarily changing the vehicle height from the outside by making a slight change or addition inside the leveling valve. It is intended to provide a valve.

[0009]

According to the present invention, there is provided a leveling valve connected between an air source and an air spring for controlling the supply and exhaust of air to and from the air spring. A casing provided at a predetermined distance in the axial direction such that the air valve and an exhaust valve for discharging air from the air spring are respectively opened and closed by displacement in the axial direction, and sliding in the casing in the axial direction. A sliding piston movably disposed, a cam groove formed in a circumferential direction on an outer peripheral surface of the sliding piston, and being displaced in an axial direction according to a rotation angle; A rotor that is rotatably supported in a sleeve that is protruded sideways so as to be orthogonal to the rotor and that is attached to an outer end of the rotor. A lever for rotating the rotor by rotating in accordance with the distance between the vehicle body and the axle; and An eccentric pin which is engaged with a cam groove of a piston and converts the rotational movement of the rotor into a sliding movement of the sliding piston; and an eccentric pin provided at a tip end of the sliding piston, wherein the air supply valve and the exhaust valve are provided. An operating member for displacing the valve together in the axial direction, a driving unit attached to the axial end of the casing and driving the sliding piston to rotate, and a controller for controlling the driving unit. It is characterized by having each.

[0010]

Therefore, when the sliding piston is rotated by the controller through the driving means in a state where the lever attached to the outer end of the rotor is in the neutral rotation position, the sliding piston is formed on the outer peripheral surface of the sliding piston. Since the position of the cam groove that is engaged with the eccentric pin changes in the axial direction, the sliding piston will move in the axial direction,
The air supply valve or the exhaust valve is opened by the movement of the operating member provided at the tip of such a sliding piston, whereby the operation of supplying and discharging air to and from the air spring is performed so that the vehicle height changes. Become.

[0011]

FIG. 2 shows a bus having a leveling valve according to an embodiment of the present invention.
Has a frame 11 underneath. The frame 11 suspends the axle 13 via an air spring 12. Wheels 14 are attached to both ends of the axle 13 as shown in FIG.

This bus has an air tank 17 as an air source, and supplies and discharges air from the air tank 17 to the air spring 12 via a leveling valve 18. That is, the air tank 17 and the leveling valve 18 are connected by the air pipe 19, and the leveling valve 18 and the air sprig 12 are connected by the air pipe 20. The lever 21 of the leveling valve 18 is connected to the axle 13 via the link 22.
It is adapted to be connected to the tip of the connecting rod 23 on the side.

[0013] As shown in FIG.
6 is fixed to the tip of the rotor 27 of the leveling valve 18. The rotor 27 is rotatably supported in a sleeve 29 protruding from the side of the casing 28. In addition, the circumferential groove 25 formed in the rotor 27 is engaged with the stopper bolt 30, and the stopper bolt 30 allows the rotor 27 to rotate freely and restrict the movement in the axial direction. Further, the rotor 27 has an eccentric pin 31 on the tip side thereof. The eccentric pin 31 is housed in a cam groove 33 of a sliding piston 32 which is slidably supported in a vertical direction in a casing 28. I have.

FIG. 4 is an exploded view of such a sliding piston 32. A cam groove 33 formed on the outer peripheral surface of the sliding piston 32 has a standard area 34 at the center thereof. High level area 3 so that
5 and a low-level region 36 are provided on both sides.

An inlet port 39 is provided at an upper end of the casing 28 of the leveling valve 18 as shown in FIG. 1, and a check valve 40 is disposed so as to close the inlet port 39, and a spring 41 is provided. The check valve 40 is pressed upward. An opening 43 is formed in a partition wall 42 formed so as to partition the space in the casing 28 in the lateral direction, and an air supply valve 44 is attached to the opening 43 so as to be openable and closable. The air supply valve 44 is connected to the spring 41.
, Thereby closing the opening 43. An air supply port 45 projecting in the lateral direction is formed so as to communicate with the space below the partition wall 42.

The air supply valve 44 is integrally provided with a projection 46 projecting downward, and the lower end of the projection 46 comes into contact with the exhaust valve 47. The exhaust valve 47 is further pressed downward by a spring 48 and is received by a receiving seat 49 formed on the casing 28. A plurality of cuts 50 are formed in the receiving seat 49 in the radial direction. Further, a through hole 51 is formed below the receiving seat 49, and a sleeve 52 is slidably disposed in the through hole 51, and the upper end thereof is in contact with the lower surface of the exhaust valve 47. A lateral hole 54 is formed in the center hole 53 of the sleeve 52.

A spring 55 surrounds the sleeve 52.
The sliding piston 32 pressed by the spring 55 has an exhaust passage 56 vertically communicated therewith. An exhaust port 57 is formed at a lower portion of the casing 28. And the exhaust passage 56
A central hole 58 is formed in the center of the sliding piston 32 having a spline groove 59, and a spline groove 59 is formed in the inner peripheral surface of the central hole 58. 61 is the spline groove 59
Is engaged. Moreover, the rotation of the servomotor 60 is controlled by the controller 62. A changeover switch 63 is connected to the controller 62. A specific configuration of the controller 62 and the switch 63 for controlling the rotation of the servomotor 60 is shown in FIG.
Such a circuit may be used.

Next, the leveling valve 18 as described above is used.
Will be described. When the amount of air filled in the air spring 12 is appropriate in relation to the weight of the vehicle body and the vehicle height is at the correct height, the lever 21 of the leveling valve 18 is in a horizontal state. . At this time, as shown in FIG. 1, the opening 43 of the partition wall 42 is closed by the air supply valve 44 and the sleeve 52 is closed.
The upper end is closed by an exhaust valve 47, and neither the air supply operation from the air tank 17 to the air spring 12 nor the exhaust operation from the air spring 12 is performed.

On the other hand, when the weight of the vehicle increases and the air spring 12 is compressed to lower the vehicle height,
Since the distance between the axle 13 and the frame 11 shown in FIG. 2 is reduced, the lever 21 of the leveling valve 18 is
Is rotated upward as shown in FIG. When the lever 21 is rotated upward, the rotor 27 also rotates in the same direction, and the eccentric pin 31 pushes the sliding piston 32 upward through the cam groove 33. Therefore, the sleeve 52 attached to the piston 32 pushes the exhaust valve 47. Then, the exhaust valve 47 moves upward and presses the protrusion 46 of the air supply valve 44 to separate the air supply valve 44 from the edge of the opening 43 of the partition wall 42. Therefore, the check valve 40 is pushed downward by air pressure. Therefore, the compressed air in the air tank 17 passes through the inlet port 39 and passes through the opening 43 of the partition wall 42.
Through the air supply port 45 and the air spring 12
Will be filled. At this time, the sleeve 52
The exhaust operation is not performed because the upper end of the exhaust valve 47 is closed by the lower surface of the exhaust valve 47.

When the compressed air in the air tank 17 is filled into the air spring 12 through the leveling valve 18, the air spring 12 gradually expands and pushes up the vehicle body 10. When the height of the vehicle body 10 is raised to the standard height, the lever 21 returns to the original horizontal state, whereby the sliding piston 32 is returned to the original position by the eccentric pin 31 of the rotor 27. Is done. Thereby, the air supply valve 44 is closed, and the check valve 40 closes the inlet port 39, and returns to the state shown in FIG.

Next, when the weight of the vehicle body decreases, the air spring 12 expands due to the internal air pressure, and the vehicle height increases. When the vehicle height is higher than the standard height, the distance between the axle 13 and the frame 11 increases, so that the lever 21 of the leveling valve 18 is rotated downward as shown in FIG. Then, the eccentric pin 31 of the rotor 27 to which the lever 21 is attached is moved to the cam groove 33 of the sliding piston 32.
Is pushed downward, and the sliding piston 32 is slid downward. Then, the sleeve 52 fixed to the upper end of the sliding piston 32 also slides down similarly. However, the exhaust valve 47 is connected to the receiving seat 49 of the casing 28.
Therefore, the lower surface of the exhaust valve 47 and the upper end of the sleeve 52 are separated from each other.

Accordingly, as indicated by arrows in FIG. 7, the compressed air in the air spring 12 flows from the cut 50 of the receiving seat 49 below the exhaust valve 47 to the center hole 53 of the sleeve 52 through the air supply port 45, After passing through the passage 54, the gas passes through the exhaust passage 56 of the sliding piston 32, and is discharged to the outside through an exhaust port 57 formed in a lower portion of the casing 28. By this operation, the air spring 12 contracts gradually, and the vehicle height falls to the standard state. When the vehicle height reaches the standard state, the lever 21 returns to a substantially horizontal state. Then this lever 21
Is transmitted to the sliding piston 32 via the eccentric pin 31 of the rotor 27, whereby the sliding piston 32 returns to the standard position. Then, the state as shown in FIG. 1 is obtained, and the upper end of the sleeve 52 contacts the lower surface of the exhaust valve 47,
Close the exhaust port and stop the exhaust operation.

Next, the operation for intentionally moving the vehicle height to a position higher than the standard position will be described with reference to FIG.
When the changeover switch 63 provided in the driver's seat is switched to the high level side, the servo motor 60 is rotated by the controller 62. The rotation of the servomotor 60 is transmitted to the sliding piston 32 via the spline shaft 61 and the spline groove 59, and the sliding piston 32 rotates in the casing 28. Cam groove 3 of sliding piston 32
The eccentric pin 31 of the rotor 27 is engaged with 3, and the position of the eccentric pin 31 is determined by the lever 21, so that the eccentric pin 31 is held at a fixed position unless the lever 21 rotates. Therefore, when the sliding piston 32 is rotated by the motor 60, the sliding piston 32 moves in the axial direction in accordance with the stroke of the cam groove 33, and when the switch 63 is switched to the high level region, the sliding piston 32 shown in FIG. The standard area 34 and the high level area 35 of the cam groove 33 shown in FIG.
Is stroked in the axial direction by an amount corresponding to the displacement.

When the sliding piston 32 is moved in the axial direction by a predetermined amount as shown in FIG.
Will be pushed up. Then, this exhaust valve 47 becomes the projection 4
6, the air supply valve 44 is pushed up, and the air supply valve 44 is separated from the edge of the opening 43. Accordingly, the check valve 40 is opened by air pressure, air flows from the inlet port 39 through the opening 43 to the air supply port 45 side as shown by an arrow in FIG.

In this way, the air spring 12 is
As shown in (2), the vehicle height is increased. The distance between the axle 13 and the frame 11 is increased in conjunction with such an operation of increasing the vehicle height.
1 is gradually turned downward. Then, this rotation is transmitted to the cam groove 33 of the sliding piston 32 by the eccentric pin 31 of the rotor 27, and the sliding piston 32 moves downward in the casing 28 and returns to the original position. Then, the sleeve 52 is also lowered, and the air supply valve 44 pushed up via the exhaust valve 47 closes the opening 43 of the partition wall 42, thereby stopping the air supply operation. Therefore, the air spring 12 expands, and the air supply operation is stopped when the vehicle height is high. In this case, as shown in FIG. 9, the lever 21 stops in a state where it is rotated downward.

Next, when the changeover switch 63 is switched to the low level side, the servomotor 60 is rotated in the reverse direction via the controller 62, whereby the sliding piston 32 is moved in the casing 28 by the cam. It moves downward by the groove 33. Accordingly, in this case, the sleeve 52 moves downward together with the sliding piston 32 as shown in FIG. 10, and the upper end of the sleeve 52 is separated from the exhaust valve 47 so that the exhaust valve 47 is opened. Then, the air in the air spring 12 is discharged through the air supply port 45, and the vehicle height decreases. When the vehicle height decreases to a predetermined height, the distance between the axle 13 and the frame 11 gradually decreases, so that the lever 21 rotates upward and the sliding piston 32 is moved by the eccentric pin 31 of the rotor 27. The pump 52 is moved upward, and the sleeve 52 comes into contact with the lower surface of the exhaust valve 47 to finish the exhaust operation. Therefore, in this case, the lever 21 is tilted upward, and the exhaust operation is stopped at a low vehicle height. That is, the vehicle height is stopped at the predetermined down position.

As described above, in the leveling valve 18 according to the present embodiment, the cam groove 33 is formed on the outer peripheral surface of the sliding piston 32 provided inside the casing 28, and the shape of the cam groove 33 is shown in FIG. It is shaped as shown. The changeover switch 63 and the controller 62
By rotating the servo motor 60, the sliding piston 32 is rotated in the casing 28, and the cam grooves 33 are adjusted to the standard height, the height of the vehicle, and the height of the vehicle when the vehicle height is lowered. In this, leveling is made possible. Therefore, the leveling valve having the vehicle height adjusting function of the air spring can be provided with a total of three types of vehicle height adjusting functions, that is, the standard height, the vehicle height raised and lowered relative to the standard height.

[0028]

As described above, according to the present invention, the air supply valve for supplying air to the air spring and the exhaust valve for discharging air from the air spring open and close by an axial displacement. A casing provided at a distance, a sliding piston slidably disposed in the casing in the axial direction thereof, and a circumferentially formed on the outer peripheral surface of the sliding piston, the rotating piston having a rotational angle. A cam groove that is displaced in the axial direction in response thereto, a rotor that is rotatably supported in a sleeve that protrudes sideways so as to be orthogonal to the axis of the casing, and that is rotatably supported. A lever attached to the outer end, which rotates according to the distance between the vehicle body and the axle to rotate the rotor, and is implanted at the inner end of the rotor in a state offset from its center. You An eccentric pin which is engaged with the cam groove of the sliding piston and converts the rotational motion of the rotor into the sliding motion of the sliding piston; Operating member for displacing the sliding piston together in the axial direction, a driving means mounted on the axial end of the casing, for driving the sliding piston to rotate, and a controller for controlling the driving means, respectively. It was done. Therefore, according to such a configuration, when the driving means is controlled by the controller and the sliding piston is rotated in the casing in a state where the lever attached to the rotor is in the neutral rotation position, the sliding is performed. Since the cam groove of the moving piston is engaged with the eccentric pin of the rotor, the sliding piston moves in the axial direction in the casing. Therefore, the operating member provided at the tip of the sliding piston moves to move the supply valve and the exhaust valve in the casing in the axial direction. Therefore, it is possible to perform the air supply / exhaust operation while the lever is in the neutral state, and it is possible to intentionally raise or lower the vehicle, so that any height adjustment of the vehicle height can be performed. Become. Further, according to the present invention, it is possible to further incorporate a sliding piston, a rotor, an operating member, and a driving unit into a casing in which an air supply valve and an exhaust valve are incorporated, thereby forming a single unit. The accuracy of the vehicle height adjustment device including the leveling valve as a system is improved, and the accuracy control is facilitated. Further, such a leveling valve may be assembled as it is in a completely assembled state, so that not only the assembling to the vehicle is facilitated but also the parts management can be easily performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a leveling valve according to one embodiment of the present invention.

FIG. 2 is a side view of a main part showing a suspension device for a front wheel of a bus provided with the leveling valve.

FIG. 3 is an external perspective view of the main part.

FIG. 4 is a developed front view showing a shape of a cam groove of the sliding piston.

FIG. 5 is a circuit diagram of a control system of the servomotor.

FIG. 6 is a longitudinal sectional view of the leveling valve in a state where the vehicle height is lowered.

FIG. 7 is a longitudinal sectional view of the leveling valve in a state where the vehicle height is increased.

FIG. 8 is a vertical sectional view of a leveling valve showing an operation of increasing a vehicle height.

FIG. 9 is a front view of a main part of the suspension device.

FIG. 10 is a longitudinal sectional view of a leveling valve showing an operation of lowering the vehicle height.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Body 11 Frame 12 Air spring 13 Axle 17 Air tank 18 Leveling valve 21 Lever 22 Link 27 Rotor 28 Casing 31 Eccentric pin 32 Sliding piston 33 Cam groove 44 Air supply valve 45 Air supply port 47 Exhaust valve 49 Seat seat 52 Sleeve 57 Exhaust port 58 Center hole 59 Spline groove 60 Servo motor 61 Spline shaft 63 Changeover switch

Claims (1)

(57) [Claims] A leveling valve connected between an air source and an air spring for controlling supply and exhaust of air to and from the air spring, wherein the air supply valve supplies air to the air spring; A casing provided at a predetermined distance in the axial direction so that an exhaust valve for discharging the gas is opened and closed by the displacement in the axial direction, and a slide slidably disposed in the casing in the axial direction. A dynamic piston, a cam groove formed along the circumferential direction on the outer peripheral surface of the sliding piston, and being displaced in the axial direction according to a rotation angle, laterally perpendicular to the axis of the casing. A rotor that is rotatably supported in a sleeve that is connected to the body and that is attached to an outer end of the rotor and that is disposed between the vehicle body and the axle. A lever that rotates according to the distance to rotate the rotor, and is implanted at an inner end of the rotor so as to be deviated from the center thereof, engaged with the cam groove of the sliding piston, An eccentric pin for converting the rotational movement of the rotor into a sliding movement of the sliding piston; and an eccentric pin provided at the tip of the sliding piston, displacing the air supply valve and the exhaust valve together in the axial direction. An operating member to be mounted, attached to an axial end of the casing,
A leveling valve comprising: a driving unit that rotationally drives the sliding piston; and a controller that controls the driving unit.