JP4019642B2 - Vehicle height adjustable air suspension system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle height-adjustable air suspension device, and more specifically, a vehicle that includes a compressed air source, a pneumatic circuit, and an air spring, and maintains the vehicle height in a fixed position under the automatic control of a leveling valve. The present invention relates to a highly adjustable air suspension device.
[0002]
[Prior art]
2. Description of the Related Art As a vehicle suspension device, an air suspension device (air spring type suspension device) using an air elastic shock absorbing action is known. As such an air suspension device, a configuration having a kneeling function for arbitrarily adjusting the height of a large vehicle such as a bus or a truck is known. An air suspension apparatus having a kneeling function has been already put into practical use as a suspension apparatus for a non-step bus that places importance on boarding / exiting performance, for example, because the height of the entrance / exit can be adjusted arbitrarily.
[0003]
In general, this type of air suspension device includes a leveling valve that controls an air spring, and the leveling valve compensates for a change in load so that the air pressure of the air spring is always maintained during general driving. Is variably controlled. The air suspension device also includes vehicle height control means (kneading means) that cancels the auto-leveling function when a passenger gets on and off, loads or unloads a load, and makes the vehicle height arbitrarily adjustable. For example, the vehicle height control means disclosed in Japanese Patent Application Laid-Open No. 60-161206 incorporates a suction valve and a discharge valve in a leveling valve and compresses three types of electromagnetically operated on / off valves that can be controlled remotely with a leveling valve. It is structured so as to be interposed between air supply sources, and is configured to be able to arbitrarily select an auto leveling function, a vehicle body raising function and a vehicle body lowering function by controlling the opening / closing operation of each on-off valve. Yes. Further, the vehicle height control means disclosed in Japanese Patent Application Laid-Open No. Hei 8-2-2232 has an electromagnetically operated intake valve arranged in parallel with a leveling valve and an electromagnetically operated exhaust valve connected in series between the leveling valve and an air spring. When the vehicle is raised or lowered, the air spring is directly connected to the compressed air supply source or the exhaust port, and the air pressure of the air spring is variably controlled in a short time to raise and lower the vehicle. Configured to run quickly.
[0004]
[Problems to be solved by the invention]
However, the vehicle height control means having such a configuration not only complicates the configuration of the pneumatic circuit around the leveling valve, but also complicates the operation of a plurality of on-off valves or three-way valves reliably and strictly. A control system is required. In addition, in the leveling valve having a structure in which the intake valve and the discharge valve are built into the leveling valve, the structure of the leveling valve itself is complicated, and the air spring and the compressed air supply source or the exhaust port are connected when the vehicle body is raised and lowered. In the vehicle height control means configured to be directly connected, not only a bypass circuit that bypasses the leveling valve is additionally required, but an exhaust valve must be interposed between the leveling valve and the air spring. Therefore, an exhaust valve must be provided for each wheel in order to execute vehicle height control for all the wheels as in a full kneeling vehicle.
[0005]
On the other hand, a method for controlling the vehicle height at the time of kneeling by the function of the leveling valve itself can be considered, but the operation lever for controlling the operation of the leveling valve is generally an axle side (axle side) via a sensing rod. Since the vibration of the axle-side structure during travel is transmitted to the rod, the initial setting and fine adjustment of the rod and lever are very difficult in practice. In reality, there are circumstances that are difficult to implement.
[0006]
The present invention has been made in view of such circumstances, and an object thereof is to provide a single vehicle height control means for a plurality of wheels without complicating the structure of a pneumatic circuit and a leveling valve. Is to provide a vehicle height-adjustable air suspension device capable of executing vehicle height control during kneeling.
[0007]
[Means and Actions for Solving the Problems]
In order to achieve the above object, the present inventor specifically analyzed conditions when passengers get on and off, loading and unloading loads. The present invention has been achieved based on such knowledge.
[0008]
That is, the present invention includes a compressed air source (AT), a pneumatic circuit and an air spring (AS), and maintains the vehicle height at a fixed position under automatic control of the leveling valve (5) constituting the pneumatic circuit. In the vehicle height adjustable air suspension device,
A check valve (40) and a three-way valve (1) are disposed between the compressed air source (AT) and the leveling valve (AS), and the check valve (40) is connected to the compressed air source (AT). The three-way valve (1) is oriented to permit the flow of air flow from the three-way valve (1) to the three-way valve (1) and to block the air flow from the three-way valve (1) to the compressed air source (AT). A movable valve body (20), a valve chamber (17), an actuator (30), and an atmosphere release port (12) .The actuator (30) opens the movable valve body (20) to the compressed air supply position and to the atmosphere. The valve chamber (17) is connected to the check valve (40) and the leveling valve (5) in fluid communication with each other in the supply position, and the atmosphere release port ( 12) is closed, and in the open position, the fluid communication between the check valve (40) and the leveling valve (5) is shut off, and the leveling valve (5) is opened to the atmosphere. Port (12) and communicates,
The leveling valve (5) includes a valve body storage chamber (57), a stationary valve body (72), a valve seat (60), a valve body biasing means (56), and a valve body drive member (70). The body accommodating chamber (57) communicates with the valve chamber (17) of the three-way valve (1), and the valve body urging means (56) connects the stationary valve body (57) to the valve seat (60). The stationary valve body (72) is seated on the valve seat (60) under the pressure of compressed air supplied to the valve body storage chamber (57) at a vehicle height fixed position. The fluid communication between the three-way valve (1) and the air spring (AS) is cut off, and the valve body driving member (70) presses the stationary valve body (72) when the vehicle is lowered to press the valve seat ( 60), the three-way valve (1) and the air spring (AS) communicate with each other,
There is provided a vehicle height-adjustable air suspension device characterized in that the vehicle height is lowered from a fixed position by switching control of the three-way valve (1) from a compressed air supply position to an atmospheric release position.
[0009]
According to the above configuration of the present invention, the check valve (40) and the three-way valve (1) are disposed between the compressed air source (AT) and the leveling valve (5). One vehicle height control means can be provided. The check valve (40) prevents the air in the air spring (AS) from flowing back to the compressed air source (AT) through the three-way valve (1) due to an increase in air pressure of the air spring (AS) and a leveling valve. The air pressure in the valve body storage chamber (57) of (5) is maintained at a predetermined pressure. The leveling valve (5) converts the increase / decrease of the vehicle height that occurs during general traveling of the vehicle into the vertical movement of the valve body drive member (70), and the valve body drive member (70), the stationary valve body (72) and the valve seat ( According to the position change of 60), supply / discharge control of compressed air to the air spring (AS) is executed. The three-way valve (1) is switched to the atmospheric release position when the vehicle height is adjusted during kneeling, the valve body storage chamber (57) of the leveling valve (5) is opened to the atmosphere, the pressure is reduced, and the stationary valve body (72) is The valve seat (60) is separated by the pressure difference between the front and back of the valve body. As a result, the air spring (AS) is released to the atmosphere via the leveling valve (5), and the vehicle height decreases. The valve body drive member (70) presses the stationary valve body (72) away from the valve seat (60) as the vehicle height is lowered, and the three-way valve (1) and the air spring (AS) Since the mutual communication state is maintained, the air spring (AS) is substantially completely opened to the atmosphere.
[0010]
To return the vehicle height to the fixed position, the three-way valve (1) can be switched to the compressed air supply position, and the compressed air from the compressed air source (AT) is supplied to the three-way valve (1) and the valve body storage chamber (57 ) To the air spring (AS). As a result, the air spring (AS) extends to the initial position, the vehicle height returns to the fixed position, and the stationary valve body (72) moves along with the valve seat (60) as the internal pressure of the valve body storage chamber (57) increases. ).
[0011]
As described above, according to the air suspension device having the above-described configuration, the vehicle height control at the time of kneeling can be executed by providing the single three-way valve (1) for the plurality of air springs (AS). The pneumatic circuit is not complicated, and it is not necessary to provide a check valve on the leveling valve (5), so that the structure of the leveling valve (5) can be simplified.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
According to a preferred embodiment of the present invention, the supply / exhaust port (13) of the three-way valve (1) is connected to a plurality of leveling valves (5). Preferably, the check valve (40) is incorporated in the valve housing of the three-way valve (1), and the check valve (40) is disposed adjacent to the supply air inflow port (11) of the three-way valve (1). Is done.
[0013]
In a further preferred embodiment of the present invention, the actuator (30) incorporates an electromagnetic solenoid (35), and displaces the movable valve body (20) to the atmospheric release position when the electromagnetic solenoid (35) is energized. Preferably, energization / non-energization of the electromagnetic solenoid (35) is executed under the control of the control unit (CU) of the vehicle.
[0014]
Preferably, the valve body driving member (70) is formed of a hollow member having a flow path (73) whose top surface and bottom surface are open at the shaft core portion. Preferably, the hollow member is formed as a cylindrical member disposed concentrically on the central axis of the valve housing (53). An air release chamber (58) that is open to the atmosphere is formed below the valve body drive member (70). The upper end surface of the valve body driving member (70) contacts the stationary valve body (72) at the vehicle height fixed position, and closes the top surface opening of the flow path (73). On the other hand, the valve body drive member (70) descends when the vehicle body is raised and is separated from the stationary valve body (72) to open the top surface opening.As a result, the air spring (AS) passes through the flow path (73). And communicates with the open air chamber (58).
[0015]
【Example】
FIG. 1 is a system configuration diagram showing the configuration of a vehicle height-adjustable air suspension device according to an embodiment of the present invention.
The vehicle height adjustment type air suspension device of this embodiment includes an air tank AT, an electromagnetically operated three-way valve 1, a leveling valve 5, and an air spring AS. The air tank AT constitutes a compressed air supply source capable of supplying pressurized air to the air spring AS. The air tank AT stores compressed air that has been pressurized and dehumidified by an air compressor and an air dryer (not shown), and the air pressure of the air tank AT is adjusted by a governor (not shown). An air supply port 2 of the air tank AT is connected to an air supply inflow port 11 of the three-way valve 1 via an air supply line L1. The three-way valve 1 includes an exhaust port 12 that can be opened to the atmosphere, and includes an air supply / exhaust port 13 connected to the air supply / exhaust line L2, and the air supply / exhaust port 13 communicates with an air supply port 50 of the leveling valve 5. . The valve housing 53 of the leveling valve 5 is fixed to the sprung structure US. The leveling valve 5 includes an exhaust port 51 that can be opened to the atmosphere, and also includes an air supply / exhaust port 52 connected to the air supply / exhaust flow path L3. The air supply / exhaust port 52 communicates with the air supply / exhaust port 3 of the air spring AS. . The sensing rod 7 has a distal end portion of the actuating lever 6 that is articulated to the lifting / lowering exhaust valve 70 of the leveling valve 5 and a proximal end portion of the actuating lever 6 mechanically linked to a vehicle height control air cylinder (not shown). Are articulated. The vehicle height control air cylinder is attached to an unsprung system structure DS including an axle. When the distance H between the structures US: DS fluctuates during general traveling, the operating lever 6 swings up and down in accordance with the change in the distance H, and mechanically controls the operation of the leveling valve 5.
[0016]
FIG. 2 is a longitudinal sectional view showing the structure of the leveling valve 5. During normal travel, the initial vehicle height is maintained, and the operating lever 6 is positioned at the neutral position (horizontal position) as shown in FIG.
[0017]
The leveling valve 5 includes a cylindrical valve housing 53 and incorporates a small-diameter cylindrical up-and-down exhaust valve 70 disposed concentrically at the center of the housing 53. The housing 53 includes an air supply port 50 at the upper end. A lower end portion of the housing 53 is closed by a bottom plate 55. A cylindrical valve seat 60 is disposed at the same height as the air supply / exhaust port 52. The outer diameter of the valve seat 60 substantially matches the inner diameter of the housing 53, and an airtight seal member 65 is interposed between the outer peripheral surface of the valve seat 60 and the inner peripheral surface of the housing 53. The air supply / exhaust flow path 62 penetrates the wall of the valve seat 60 in the radial direction, and the hollow portion 61 of the valve seat 60 and the air supply / exhaust port 52 communicate with each other.
[0018]
The exhaust valve 70 includes a hollow valve shaft 71 that vertically penetrates the hollow portion 61, and a circular stationary valve body 72 that detachably contacts the upper end surface of the valve shaft 71. An airtight seal member 75 is interposed between the outer peripheral surface of the valve shaft 71 and the inner peripheral surface of the valve seat 60, and the valve shaft 71 is slidably held by the airtight seal member 75. A compression coil spring 56 is disposed in a valve body accommodating chamber 57 formed between the valve seat 60 and the air supply port 50. The spring 56 is inserted between the air supply port 50 and the valve body 72 and biases the valve body 72 against the seating surface 63 of the valve seat 60. The valve body 72 seated on the seating surface 63 under the pressure of the valve body storage chamber 57 blocks fluid communication between the valve body storage chamber 57 and the hollow portion 61.
[0019]
An exhaust passage 73 is formed at the center of the valve shaft 71. The upper end portion of the exhaust passage 73 is closed by the valve body 72, while the lower end portion of the exhaust passage 73 is always in communication with the exhaust chamber 58 and is always open to the atmosphere via the exhaust chamber 58. The distal end portion of the operating lever 6 extends into the exhaust chamber 58. A small-diameter eccentric pin 67 attached to the rotating shaft of the lever 6 is engaged with the pin sliding groove 75 of the valve shaft 71, and the swinging or rotating motion of the lever 6 is converted to the vertical motion of the valve shaft 71. To do.
[0020]
With reference to FIG. 1, the configuration of the electromagnetically operated three-way valve 1 disposed between the leveling valve 5 and the air tank AT will be described.
The three-way valve 1 includes a valve main body 10 having an air supply inflow port 11, an exhaust port 12 and an air supply / exhaust port 13, and an electromagnetically operated actuator 30 that drives a movable valve body 20 and a valve shaft 21 of the valve main body 10. Is done.
[0021]
The valve body 10 includes a check valve 40 that can close the supply air inflow port 11. A check valve chamber 41 of the check valve 40 is formed adjacent to the air supply inflow port 11. A compression coil spring 42 is disposed in the check valve chamber 41 and biases the check valve 40 toward the air supply inflow port 11. The check valve 40 prevents the backflow of the compressed air to the air tank AS when the internal pressure of the air spring AS increases transiently at the time of bumping the vehicle, and the internal pressure of the valve body accommodating chamber 57 of the leveling valve 5 is reduced. When lowered, it functions to supply compressed air from the air tank AS to the valve body accommodating chamber 57.
[0022]
The check valve chamber 41 communicates with the valve chamber 17 via the vertical flow path 15 and the horizontal flow path 16, and the valve chamber 17 always communicates with the supply / exhaust port 13. The valve shaft 21 extends through the horizontal through hole 22 and the flow path 16 of the valve body 10 into the valve chamber 17. An airtight seal material 23 is interposed between the outer peripheral surface of the valve shaft 21 and the inner peripheral surface of the through hole 22. The valve body 20 is integrally disposed at the distal end portion of the valve shaft 21, sits on the seating surface 18 of the exhaust port 12, and closes the exhaust port 12.
[0023]
The actuator 30 includes an actuator 32, a compression coil spring 33, a spring retainer 34, and an electromagnetic solenoid 35 disposed in the casing 31. The actuator 32 is integrally connected to the proximal end portion of the valve shaft 21. The spring 33 always urges the operating element 32 via the spring retainer 34, and holds the valve shaft 21 in the compressed air supply position (FIG. 1) when the electromagnetic solenoid 35 is not energized. The electromagnetic solenoid 35 is connected to a power source via an operation switch SW, and the operation switch SW is remotely controlled by a vehicle control unit CU. The electromagnetic solenoid 35 is energized when the operation switch SW is turned ON, horizontally displaces the actuator 32 against the elastic force of the spring 33, and pulls the valve shaft 21 into the actuator 30. The valve body 20 is separated from the seating surface 18 to release the valve chamber 17 to the atmosphere, and is seated on a seating surface 19 located on the opposite side of the seating surface 18 to block communication between the flow path 16 and the valve chamber 17. .
[0024]
Next, the operation of the vehicle height-adjustable air suspension apparatus having the above configuration will be described.
In the general traveling state shown in FIGS. 1 and 2, the three-way valve 1 is held at the compressed air supply position (FIG. 1), and the movable valve body 20 closes the exhaust port 12. The stationary valve body 72 is seated on the seating surface 63 and blocks fluid communication between the valve body accommodating chamber 57 and the hollow portion 61. The upper end surface of the exhaust valve 70 is in close contact with the lower surface of the stationary valve body 72 and blocks communication between the air supply / exhaust port 52 and the exhaust chamber 58.
[0025]
FIG. 3 is a longitudinal sectional view showing the behavior of the leveling valve 5 when the vehicle body is lowered during general traveling.
When the load is increased, the vehicle body is displaced relative to the axle and the distance H between the sprung system structure US and the unsprung system structure DS is shortened. Rotate clockwise. The exhaust valve 70 is biased upward by the eccentric pin 67 of the lever 6 and displaces the valve body 72 upward while maintaining a close contact state with the lower surface of the stationary valve body 72. The valve body 72 is separated from the seating surface 63, and as a result, a flow path L 5 that connects the valve body housing chamber 57 and the hollow portion 61 to each other is formed between the valve body 72 and the seating surface 63. Compressed air in the air tank AT is supplied through an air supply line L1, an air supply inflow port 11, a check valve 40, a flow path 15 and a 16-valve chamber 17, an air supply / exhaust port 13, an air supply / exhaust line L2, and an air supply port 50. As shown by arrows in FIG. 3, the air spring AS enters the valve spring accommodating chamber 57 via the flow path L5, the hollow portion 61, the air supply / exhaust flow path 62, the air supply / exhaust port 52, and the air supply / exhaust pipe L3. Supplied. The air spring AS extends to the initial position by the supply of compressed air and returns to the vehicle height fixed position.
[0026]
FIG. 4 is a longitudinal sectional view showing the behavior of the leveling valve 5 when the vehicle body is raised during general traveling.
When the load is reduced, the vehicle body is displaced relative to the axle and the distance H between the sprung system structure US and the unsprung system structure DS increases. It rotates counterclockwise. The exhaust valve 70 is biased downward by the eccentric pin 67 of the lever 6 and is displaced downward with respect to the valve seat 60. Since the stationary valve body 72 maintains the seated state on the valve seat 60, the upper end surface of the exhaust valve 70 is separated from the lower surface of the valve body 72, and the flow path interconnects the exhaust flow path 73 and the hollow portion 61. L6 is formed between the valve body 72 and the upper end surface of the exhaust valve 70. The air chamber of the air spring AS flows out into the exhaust chamber 58 via the air supply / exhaust pipe L3−supply / exhaust port 52−exhaust flow path 73, and is discharged from the exhaust port 51 to the atmosphere. The air spring AS contracts to the initial position due to the release of compressed air to the atmosphere, and returns to the vehicle height fixed position.
[0027]
When the air spring AS contracts due to a vehicle bump or the like, and the air pressure of the air spring AS rises higher than that of the air tank AT, the check valve 40 (FIG. 1) moves from the air spring AS to the air tank AT. Prevents backflow of air.
[0028]
FIG. 5 is a system configuration diagram of a vehicle height-adjustable air suspension device showing a vehicle height lowering operation during kneeling, and FIG. 6 is a longitudinal sectional view showing the behavior of the leveling valve 5 during the vehicle height lowering operation.
[0029]
When the operation switch SW is turned ON under the control of the vehicle control unit CU and the electromagnetic solenoid 35 is energized, the actuator 30 pulls the valve shaft 21 into the actuator 30, and the movable valve body 18 moves away from the seating surface 18. Thus, the exhaust port 12 is opened, the valve chamber 17 is opened to the atmosphere, and the seat 16 is seated on the seating surface 19 located on the opposite side of the seating surface 18 to block communication between the flow path 16 and the valve chamber 17.
[0030]
As a result, the valve body storage chamber 57 is opened to the atmosphere, and the internal pressure of the valve body storage chamber 57 is reduced to atmospheric pressure. Due to the differential pressure between the air pressure of the air spring AS and the internal pressure (atmospheric pressure) of the valve body storage chamber 57, the valve body 72 rises against the elastic force of the spring 56, and the valve body 72 and the seating surface 63 A flow path L5 is formed therebetween. Air in the air spring AS is supplied through the air supply / exhaust line L3—the air supply / exhaust port 52—the air supply / exhaust flow path 62—the hollow portion 61—the flow path L5—the valve body accommodating chamber 57—the supply / exhaust pipe line L2— Then, it flows out into the valve chamber 17 and is discharged from the exhaust port 12 to the atmosphere.
[0031]
FIG. 7 is a longitudinal sectional view showing the behavior of the leveling valve 5 when the vehicle body descends under kneeling control.
When the vehicle height starts to decrease with the release of air from the air spring AS, the operating lever 6 rotates in the clockwise direction as shown in FIG. 7, and the exhaust valve 70 is displaced upward, The end surface is in close contact with the lower surface of the valve body 72. As a result, the valve body 72 is prevented from being lowered by the exhaust valve 70 and is held in the raised position, and the compressed air of the air spring AS is substantially completely released into the atmosphere via the leveling valve 5 and the three-way valve 1, The car body descends to the lowest position.
[0032]
In order to return the vehicle height to the initial state, it is only necessary to turn off the operation switch SW by the control unit CU and stop energization of the electromagnetic solenoid 35. The actuator 30 displaces the actuator 32 by the elastic restoring force of the spring 33, and the valve shaft 21 protrudes from the actuator 30. The valve body 20 is separated from the seating surface 19 to communicate the flow path 16 and the valve chamber 17, and is seated on the seating surface 18 to close the exhaust port 12. As a result, the compressed air in the air tank AT is supplied from the air supply line L1—the air supply inflow port 11—the check valve 40—the flow path 15, 16—the valve chamber 17—the air supply / exhaust port 13—the air supply / exhaust line L2—the air supply port. 50 flows into the valve body storage chamber 57 through 50, and is supplied to the air spring AS through the flow path L5, the hollow portion 61, the air supply / exhaust flow path 62, the air supply / exhaust port 52, and the air supply / exhaust pipe L3. The air spring AS extends to the initial position by the supply of compressed air and returns to the vehicle height fixed position.
[0033]
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-described embodiments, and various modifications or changes can be made within the scope of the present invention described in the claims. It goes without saying that it is possible.
[0034]
For example, in the above embodiment, the check valve 40 is incorporated in the three-way valve, but the check valve may be interposed in the pipe line L1.
[0035]
【The invention's effect】
As described above, according to the above configuration of the present invention, the knee height can be reduced by arranging a single vehicle height control means for a plurality of wheels without complicating the structure of the pneumatic circuit and the leveling valve. A vehicle height-adjustable air suspension device capable of performing vehicle height control at the time is provided.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram showing a configuration of a vehicle height adjustment type air suspension device according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing a structure of a leveling valve, and an operating lever is located at a neutral position (horizontal position).
FIG. 3 is a longitudinal sectional view showing the behavior of the leveling valve when the vehicle body is lowered.
FIG. 4 is a longitudinal sectional view showing the behavior of the leveling valve when the vehicle body is raised.
FIG. 5 is a system configuration diagram of a vehicle height adjustable air suspension device showing a vehicle height lowering operation during kneeling.
FIG. 6 is a longitudinal sectional view showing the behavior of the leveling valve during the vehicle height lowering operation.
FIG. 7 is a longitudinal sectional view showing the behavior of the leveling valve when the vehicle body descends under kneeling control.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electromagnetically operated three-way valve 2 Supply port 3 Supply / exhaust port 5 Leveling valve 6 Actuation lever 10 Valve body 11 Supply air inflow port 12 Exhaust port 13 Supply / exhaust port 20 Valve element 21 Valve shaft 30 Electromagnetically operated actuator 35 Electromagnetic solenoid 40 Check valve 50 Air supply port 51 Exhaust port 52 Supply / exhaust port 70 Lift exhaust valve
AT air tank
AS Air Spring
L1 Air supply line
L2 Supply / exhaust pipeline
L3 Supply / exhaust pipeline

Claims (5)

In a vehicle height-adjustable air suspension device comprising a compressed air source, a pneumatic circuit, and an air spring, and maintaining the vehicle height at a fixed position under automatic control of a leveling valve constituting the pneumatic circuit,
A check valve and a three-way valve are disposed between the compressed air source and the leveling valve, and the check valve allows air flow from the compressed air source to the three-way valve and from the three-way valve. The three-way valve includes a movable valve body, a valve chamber, an actuator, and an atmosphere release port, the actuator including the movable valve body and a compressed air supply position. The valve chamber is selectively displaced to the atmosphere opening position, and the valve chamber connects the check valve and the leveling valve in fluid communication with each other and closes the atmosphere opening port in the supply position. Shutting off fluid communication between the check valve and the leveling valve and communicating the leveling valve with the atmosphere release port;
The leveling valve includes a valve body storage chamber, a stationary valve body, a valve seat, a valve body urging means, and a valve body drive member. The valve body storage chamber communicates with a valve chamber of the three-way valve, and the valve The body urging means urges the stationary valve body toward the valve seat, and the stationary valve body is in a vehicle height fixed position, and the valve is under pressure of compressed air supplied to the valve body housing chamber. The seat is seated, the fluid communication between the three-way valve and the air spring is shut off, and the valve body driving member presses the stationary valve body away from the valve seat when the vehicle descends, and the three-way valve The air spring is in communication with each other,
A vehicle height-adjustable air suspension apparatus characterized in that the vehicle height is lowered from a fixed position by switching control of the three-way valve from a compressed air supply position to an atmospheric release position. 2. The vehicle height-adjustable air suspension device according to claim 1, wherein the check valve is incorporated in a valve housing of the three-way valve adjacent to a supply air inflow port of the three-way valve. 3. The vehicle height-adjustable air suspension device according to claim 1, wherein the actuator includes an electromagnetic solenoid and displaces the movable valve body to an atmospheric release position when the electromagnetic solenoid is energized. Said valve body drive member comprises a channel in which the top and bottom surfaces is open from the hollow member in the shaft portion, the lower side of the valve body drive member, the air release chamber which is open to the atmosphere is formed, An upper end surface of the valve body driving member abuts on the stationary valve body at a vehicle height fixed position and closes a top surface opening of the flow path, and the valve body driving member descends when the vehicle body is raised and The vehicle height-adjustable air suspension device according to any one of claims 1 to 3, wherein the top surface opening is opened apart from the valve body, and the flow path is communicated with the air spring. The vehicle height-adjustable air suspension device according to any one of claims 1 to 4, wherein the air supply / exhaust port of the three-way valve is connected to a plurality of leveling valves.

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