阅读说明：本技术 空气悬架装置 (Air suspension device ) 是由 河合义则 酒井博史 小林宽 于 2019-09-18 设计创作，主要内容包括：空气悬架装置具备：压缩机,所述压缩机对空气进行压缩；罐,所述罐储存空气；罐侧吸入管路,所述罐侧吸入管路将罐内的压缩空气向压缩机的进气侧供给；罐用管路,所述罐用管路将压缩机的排出侧与罐相连；空气悬架,所述空气悬架经由空气干燥器与压缩机的排出侧连接；进气电磁阀,所述进气电磁阀设置于罐侧吸入管路；返回电磁阀,所述返回电磁阀设置于罐用管路；以及排气管路,所述排气管路从压缩机的排出侧与空气干燥器之间分支地设置,通过将排气电磁阀打开而与大气连接。(The air suspension device is provided with: a compressor that compresses air; a tank storing air; a tank-side suction line that supplies compressed air in the tank to an intake side of the compressor; a tank line connecting a discharge side of the compressor to the tank; an air suspension connected to a discharge side of the compressor via an air dryer; the air inlet electromagnetic valve is arranged on the tank side suction pipeline; a return solenoid valve disposed in the tank pipe; and an exhaust line branching from between the discharge side of the compressor and the air dryer, and connected to the atmosphere by opening an exhaust solenoid valve.)

1. An air suspension device, characterized by comprising:

a compressor that compresses air;

a canister configured to store air;

a first passage that supplies compressed air in the tank to a suction side of the compressor;

a second passage connecting a discharge side of the compressor with the tank;

an air suspension connected to a discharge side of the compressor via an air dryer;

a first valve disposed in the first passage;

a second valve disposed in the second passage; and

a third passage provided branched from between a discharge side of the compressor and the air dryer and connected to the atmosphere by opening a third valve,

the air dryer can be regenerated by compressed air in the air suspension by closing the first and second valves and opening the third valve.

2. The air suspension device according to claim 1,

compressed air compressed from the atmosphere is supplied to the air suspension without passing through the tank in accordance with a command from a control means.

3. The air suspension device according to claim 1,

the air suspension device further includes a fourth path connecting the air dryer and the air suspension,

and a fourth valve is arranged on the fourth passage.

4. The air suspension device according to claim 1,

a first throttle portion is provided between the air dryer and the fourth valve, and a second throttle portion is provided between the air dryer and the second valve, the throttle diameter of the first throttle portion being larger than the throttle diameter of the second throttle portion.

5. The air suspension device according to any one of claims 1 to 4,

the first valve and the second valve are two-way solenoid valves.

Technical Field

The present invention relates to an air suspension device mounted on a vehicle such as a four-wheel automobile.

Background

The air suspension device for adjusting the vehicle height of a vehicle has an open type and a closed type, and the open type air suspension device has the advantages of simple system structure and capability of reducing structural components. However, since air is compressed from an atmospheric pressure state, it takes time to raise the pressure of the compressed air to a desired pressure. On the other hand, the closed air suspension device (for example, see patent document 1) has an advantage that the pressure of the intake air can be increased to the atmospheric pressure, and therefore the pressure of the compressed air can be increased to a desired pressure in a short time.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-168271

Disclosure of Invention

Problems to be solved by the invention

However, in patent document 1, since the flow direction of the compressed air is switched by using an expensive three-way solenoid valve, there is a problem that, for example, the compressed air in the tank is likely to leak and the manufacturing cost is increased. In addition, there is a problem that the efficiency in regenerating the air dryer cannot necessarily be improved.

Means for solving the problems

The invention aims to provide an air suspension device which can restrain leakage of compressed air and efficiently regenerate an air dryer.

An air suspension device according to an embodiment of the present invention includes: a compressor that compresses air; a canister configured to store air; a first passage that supplies compressed air in the tank to a suction side of the compressor; a second passage connecting a discharge side of the compressor with the tank; an air suspension connected to a discharge side of the compressor via an air dryer; a first valve disposed in the first passage; a second valve disposed in the second passage; and a third passage provided to be branched from between a discharge side of the compressor and the air dryer, and connected to the atmosphere by opening a third valve, and the air dryer can be regenerated by compressed air in the air suspension by closing the first valve and the second valve and opening the third valve.

According to an embodiment of the present invention, the regeneration of the air dryer can be performed efficiently, and the leakage of the compressed air can be suppressed.

Drawings

Fig. 1 is a circuit diagram showing an overall configuration of an air suspension device according to a first embodiment of the present invention.

Fig. 2 is a control block diagram of the air suspension apparatus including the controller.

Fig. 3 is a flowchart showing a control process of the vehicle height adjustment by the controller.

Fig. 4 is a circuit diagram showing an air suspension device in a control state in which compressed air is sucked from a tank to raise the vehicle height.

Fig. 5 is a circuit diagram showing the air suspension device in a state where compressed air is discharged from the air suspension toward the tank to accumulate pressure and lower the vehicle height.

Fig. 6 is a circuit diagram showing the air suspension device in a state where compressed air is released from the air suspension to the outside to regenerate the air dryer in order to lower the vehicle height.

Fig. 7 is a circuit diagram showing the overall configuration of an air suspension device according to a second embodiment.

Fig. 8 is a circuit diagram showing the overall configuration of the air suspension device according to the third embodiment.

Detailed Description

Hereinafter, a case where the air suspension device according to the embodiment of the present invention is applied to a vehicle such as a four-wheel automobile will be described in detail with reference to fig. 1 to 8 of the drawings.

Here, fig. 1 to 6 show a first embodiment. In the figure, a total of 4 air suspensions 1 are provided between each axle side and a vehicle body side (none of which is shown) of the vehicle on the side of a front left wheel (FL), a front right wheel (FR), a rear left wheel (RL), and a rear right wheel (RR) of the vehicle. These air suspensions 1 are pneumatic devices that adjust the vehicle height by supplying and discharging compressed air to and from an air chamber 1C described later, in accordance with expansion and contraction of the air chamber 1C.

Each air suspension 1 is configured by, for example, a cylinder 1A attached to the vehicle axle side, a piston rod 1B that is axially and telescopically projected from the cylinder 1A and whose projecting end side is attached to the vehicle body side, and an air chamber 1C that is telescopically provided between the projecting end side of the piston rod 1B and the cylinder 1A and operates as an air spring. The air chamber 1C of each air suspension 1 is expanded or contracted in the axial direction by supplying or discharging compressed air from a branch pipe 10A described later. At this time, the piston rod 1B of each air suspension 1 extends and contracts in the axial direction from inside the cylinder 1A, and the height of the vehicle (vehicle height) is adjusted in accordance with the supply/discharge amount of the compressed air.

The compressor device 2 compresses air and supplies the compressed air to the air chamber 1C of the air suspension 1. Here, the compressor device 2 is configured to include: a compressor 3 as a compressor main body; an electric motor 4 for driving and stopping the compressor 3; an intake pipe 5 connected to a suction side 3A (hereinafter, referred to as an intake side 3A) of the compressor 3; a supply/discharge line 6 connected to the discharge side 3B of the compressor 3; an air dryer 7 and a one-way throttle valve 8 provided in the supply and discharge pipeline 6; and an intake valve 9, a tank-side intake line 13, an intake solenoid valve 14, a tank line 15, a return solenoid valve 16, a supply/discharge switching valve 17, a return line 18, an exhaust line 19, an exhaust solenoid valve 20, and the like, which will be described later.

The compressor 3, which is a compressor main body, sucks air from an intake side 3A thereof to generate compressed air, and is configured by, for example, a reciprocating compressor, a scroll compressor, or the like. The compressed air generated from the compressor 3 is supplied to an air chamber 1C of the air suspension 1 as a pneumatic device. The compressor 3 is driven to rotate by an electric motor 4 as a driving source. The electric motor 4 is driven and stopped under control of a controller 22 (see fig. 2) described later. The electric motor 4 may be a drive source such as a linear motor, for example.

An intake line 5 is connected to an intake side 3A of the compressor 3, and a supply-discharge line 6 is connected to a discharge side 3B of the compressor 3. One end of the supply/discharge pipe 6 is connected to the discharge side 3B of the compressor 3, and the other end is connected to the air duct 10 via a supply/discharge switching valve 17 described later. An air dryer 7 and a one-way throttle valve 8 are provided at intermediate positions of the supply and discharge pipe 6.

The intake pipe 5 of the compressor device 2 constitutes an intake passage of the compressor 3, and a tank-side intake pipe 13 and a return pipe 18, which will be described later, are connected to the connection point 5A. It is needless to say that the tank-side suction line 13 and the return line 18 may be connected to the intake line 5 before and after the connection point 5A.

One end of the intake duct 5 is an intake port 5B that opens to the outside of the compressor device 2 (compressor 3), and a filter (not shown) that removes dust and the like in the air is provided at the intake port 5B. The intake port 5B is a port for drawing outside air into the intake side 3A when the compressor 3 is driven. The other end of the intake pipe 5 is connected to the intake side 3A of the compressor 3, and an intake valve 9 is provided in the middle of the intake pipe 5.

The intake valve 9 is provided midway in the intake pipe 5 between the connection point 5A and the intake port 5B. The intake valve 9 is a check valve configured to draw air from the atmosphere through the intake port 5B. That is, the intake valve 9, which is a check valve, is configured to open when the pressure on the intake side 3A of the compressor 3 becomes equal to or lower than the atmospheric pressure at the position of the connection point 5A, and to draw in air from the outside (atmosphere) through the intake port 5B.

The intake valve 9 functions as a so-called intake valve, and is constituted by a check valve that allows air to flow from the intake port 5B into the intake pipe 5 (i.e., toward the connection point 5A of the intake pipe 5) and blocks the flow in the opposite direction. Therefore, when the pressure in the intake pipe 5 (i.e., on the side of the connection point 5A of the intake pipe 5) becomes a pressure (positive pressure) higher than the atmospheric pressure, the intake valve 9 is closed, and the compressed air from the air suspension 1 or the tank 12 is supplied (sucked) to the intake side 3A of the compressor 3 via the tank-side suction pipe 13, the intake solenoid valve 14, or the return pipe 18.

The supply/discharge line 6 is configured as a supply/discharge passage for supplying/discharging compressed air generated from the compressor 3 to/from the air chamber 1C of the air suspension 1. The compressed air supplied to the air chamber 1C of the air suspension 1 is discharged from the air chamber 1C through the supply/discharge pipe line 6 and the throttle portion 8A of the check throttle valve 8, for example, in a reverse flow manner in the air dryer 7 when the vehicle height is lowered, or discharged into the tank 12 described later through the tank pipe line 15 and the return solenoid valve 16 in a release manner.

Further, in the supply/discharge pipe 6, a discharge pipe 19 is branched from a connection point 6A between the discharge side 3B of the compressor 3 and the air dryer 7. A tank line 15 is branched from a connection point 6B of the supply/discharge line 6 between the check throttle valve 8 and the supply/discharge switching valve 17. In other words, the air dryer 7 and the one-way throttle valve 8 are provided in the supply/discharge line 6 at positions between the connection points 6A and 6B.

The air dryer 7 constitutes an air drying member provided in the middle of the supply and discharge pipeline 6. The air dryer 7 contains a moisture adsorbent (not shown) such as silica gel, for example, and is disposed between the discharge side 3B of the compressor 3 and the one-way throttle valve 8. The check throttle valve 8 is formed of a parallel circuit of a throttle portion 8A and a check valve 8B, and the check valve 8B is opened with respect to a forward direction flow described later without throttling the flow rate of the compressed air. However, since the check valve 8B is closed to the flow in the reverse direction and the flow rate of the compressed air at this time is throttled by the throttle unit 8A, the compressed air flows back slowly at a small flow rate in the air dryer 7.

When the high-pressure compressed air generated by the compressor 3 flows in the positive direction through the supply and discharge line 6 toward the air suspension 1, the air dryer 7 causes the compressed air to contact the moisture adsorbent therein to adsorb moisture, and supplies the dried compressed air to the air chamber 1C. On the other hand, when the compressed air (exhaust gas) discharged from the air suspension 1 (the air chamber 1C) flows in the reverse direction in the air dryer 7 (the supply and discharge pipe 6), the dried air flows in the air dryer 7 in the reverse direction, and therefore the moisture adsorbent in the air dryer 7 desorbs moisture by the dried air. Thereby, the moisture adsorbent of the air dryer 7 is regenerated, and the state is returned to the state capable of adsorbing moisture again.

The air chamber 1C of the air suspension 1 is connected to the supply/discharge line 6 of the compressor 3 via an air duct 10 and a supply/discharge switching valve 17. Here, a plurality of (for example, four) branch pipes 10A are provided in the air duct 10 so as to branch from each other. The distal end side of each branch pipe 10A is detachably connected to the air chamber 1C of the air suspension 1. A fourth passage connecting the air dryer 7 and the air suspension 1 is constituted by, for example, a part of the supply and discharge pipe 6 and the air duct 10, and a fourth valve (a supply and discharge switching valve 17 described later) is provided in the fourth passage.

The compressed air supply/exhaust valve 11 is provided in the middle of each branch pipe 10A in order to control supply/exhaust of compressed air to/from the air chamber 1C of the air suspension 1. The air supply/exhaust valve 11 is constituted by, for example, an electromagnetic switching valve (electromagnetic valve) with a 2-port 2 position. The air supply/discharge valve 11 is normally in a closed position (a), and is switched from the closed position (a) to an open position (b) when excited by a control signal from a controller 22 described later.

The air supply/discharge valves 11 may be connected between the air chamber 1C of the air suspension 1 and the branch pipe 10A. The supply/exhaust valve 11 functions as a relief valve (safety valve). Therefore, if the pressure in the air chamber 1C exceeds the relief set pressure, even in a state where the air supply/exhaust valve 11 is demagnetized, the pressure can be temporarily switched from the closed position (a) to the open position (b) to the relief valve, and the excess pressure at that time can be released into the air duct 10.

The tank 12 for storing compressed air has a connection pipe 12A made of, for example, a flexible hose. One end of the connection pipe 12A is detachably connected to the tank 12, and the other end is connected to a tank-side suction pipe 13 and a tank pipe 15, which will be described later. The connection pipe 12A of the tank 12 is connected to the intake side 3A of the compressor 3 via a tank-side suction pipe 13 as a first passage. One end of the tank-side suction line 13 is connected to the tank 12 (connection pipe 12A), and the other end is connected to the intake line 5 at the connection point 5A. That is, the connection point 5A connects the intake pipe 5 and the tank-side intake pipe 13 so that the tank-side intake pipe 13 branches off from the intake pipe 5 at a position between the intake side 3A of the compressor 3 and the intake valve 9.

The tank-side suction line 13 is provided with an intake solenoid valve 14 for supplying or stopping the supply of the compressed air in the tank 12 to the intake side 3A of the compressor 3. The intake solenoid valve 14 is constituted by, for example, a 2-port 2-position electromagnetic switching valve (solenoid valve). The intake solenoid valve 14 is normally in the closed position (c), and when excited by a control signal from the controller 22, switches from the closed position (c) to the open position (d). The intake solenoid valve 14 also functions as a relief valve (safety valve) in the same manner as the intake/exhaust valve 11.

The intake solenoid valve 14 is an on/off two-way solenoid valve composed of a closed position (c) and an open position (d), and an electromagnetic switching valve having high versatility can be used, and an expensive valve such as a three-way solenoid valve can be eliminated. As for the return solenoid valve 16 and the exhaust solenoid valve 20, which will be described later, a two-way solenoid valve having high versatility can be used, as in the intake solenoid valve 14.

The connection pipe 12A of the tank 12 is connected to the discharge side 3B of the compressor 3 via a tank pipe line 15 as a second passage. The tank pipe 15 has one end connected to the tank 12 (connection pipe 12A), and the other end branched from the supply and discharge pipe 6 at the connection point 6B. That is, the connection point 6B connects the supply/discharge line 6 and the tank line 15 such that the tank line 15 branches from the supply/discharge line 6 at a position between the one-way throttle valve 8 and the supply/discharge switching valve 17.

A return solenoid valve 16 as a return valve is provided in the tank line 15, and the return solenoid valve 16 supplies or stops the supply of the compressed air in the tank 12 to return to the supply/discharge line 6. The return solenoid valve 16 is constituted by, for example, a 2-port 2-position two-way solenoid valve (solenoid valve). The return solenoid valve 16 is normally in a closed position (e), and is switched from the closed position (e) to an open position (f) when excited by a control signal from the controller 22. When the return solenoid valve 16 is opened, for example, the pressure can be accumulated so that the compressed air in the air suspension 1 is returned to the tank 12 through the tank pipe 15. The return solenoid valve 16 also functions as a relief valve (safety valve) in the same manner as the supply/exhaust valve 11.

The supply/discharge switching valve 17 constitutes a fourth valve provided in a fourth passage (for example, a part of the supply/discharge pipe 6 and the air duct 10) connecting the air dryer 7 and the air suspension 1. Here, the supply/discharge switching valve 17 is a valve that selectively connects the air conduit 10 on the air suspension 1 side to the supply/discharge line 6 or the return line 18, and is constituted by, for example, an electromagnetic directional switching valve (i.e., a three-way electromagnetic valve) with a 3-port 2 position. That is, the supply/discharge switching valve 17 selectively switches between a supply/discharge position (g) at which compressed air generated by the compressor 3 is supplied to the air chamber 1C of the air suspension 1 or compressed air in the air chamber 1C is discharged through the supply/discharge line 6, and a return position (h) at which compressed air in the air chamber 1C is returned to the intake side 3A of the compressor 3 through the return line 18.

The return line 18 is a bypass passage provided so as to bypass the compressor 3, the supply/discharge line 6, the air dryer 7, and the one-way throttle valve 8, and one end portion thereof can be connected to the air duct 10 on the air suspension 1 side via the supply/discharge switching valve 17. The other end of the return line 18 is connected to the intake line 5 at the position of the connection point 5A. Therefore, when the supply/discharge switching valve 17 is switched to the return position (h), the return line 18 returns the compressed air discharged from the air chamber 1C of the air suspension 1 to the intake side 3A of the compressor 3 so as to bypass the supply/discharge line 6.

The exhaust line 19 is a third passage for discharging the compressed air in the supply and discharge line 6 to the outside, and an exhaust solenoid valve 20 is provided midway therein. One end of the exhaust line 19 is connected to the supply and exhaust line 6 at the position of the connection point 6A. The other end of the exhaust pipe 19 is an exhaust port 19A extending to the outside of the compressor device 2, and the tip of the exhaust port 19A is open to the outside air.

An exhaust solenoid valve 20 as an exhaust valve is provided in the exhaust line 19 as a third passage. The exhaust solenoid valve 20 is constituted by, for example, a 2-port 2-position two-way solenoid valve (solenoid valve). The exhaust solenoid valve 20 is normally in a closed position (i), and is switched from the closed position (i) to an open position (j) when excited by a control signal from the controller 22.

When the exhaust solenoid valve 20 is opened, the compressed air in the air suspension 1 can be exhausted (opened) from the exhaust port 19A to the outside via the supply/discharge pipe 6, the throttle portion 8A of the one-way throttle valve 8, the air dryer 7, and the exhaust pipe 19. When the exhaust solenoid valve 20 is opened, the compressed air in the tank 12 can be exhausted (opened) from the exhaust port 19A to the outside via the tank pipe 15, the return solenoid valve 16, the supply/discharge pipe 6, the throttle portion 8A of the one-way throttle valve 8, the air dryer 7, and the exhaust pipe 19. The exhaust solenoid valve 20 also functions as a relief valve (safety valve) in the same manner as the intake/exhaust valve 11.

Further, a pressure detector 21 is provided in the air duct 10 at a position between each branch pipe 10A and the supply/discharge switching valve 17, for example. The pressure detector 21 detects the pressure in the tank 12 via the tank line 15 when, for example, the return solenoid valve 16 is switched from the closed position (e) to the open position (f) in a state where all of the intake/exhaust valve 11, the intake solenoid valve 14, and the exhaust solenoid valve 20 are closed and the intake/exhaust switching valve 17 is returned to the intake/exhaust position (g). In a state where the intake solenoid valve 14, the return solenoid valve 16, and the exhaust solenoid valve 20 are closed, for example, when at least one of the intake and exhaust valves 11 is opened, the pressure in the air chamber 1C of the corresponding air suspension 1 can be detected by the pressure detector 21.

The controller 22 as a control means is constituted by a microcomputer or the like, for example. A pressure detector 21, a plurality of vehicle height sensors 23 (i.e., FL-side, FR-side, RL-side, RR-side vehicle height sensors 23), a selector switch 24, and the like are connected to an input side of the controller 22. The FL-side, FR-side, RL-side, and RR-side vehicle height sensors 23 detect the vehicle height based on each air suspension 1 on the front left wheel (FL), front right wheel (FR), rear left wheel (RL), and rear right wheel (RR) sides of the vehicle, respectively. The selection switch 24 is an operation switch for switching between, for example, an automatic mode for adjusting the vehicle height and a selection mode in which the driver arbitrarily changes the vehicle height according to the preference.

Here, when the operation of the selection switch 24 is selected to perform the vehicle height adjustment in the automatic mode, the controller 22 compares (determines) whether each air suspension 1 is higher or lower than a set height that is the target vehicle height, based on the vehicle height detection signals output from the FL-side, FR-side, RL-side, and RR-side vehicle height sensors 23. Based on the comparison (determination), the controller 22 performs height adjustment by the air suspensions 1 on the front left wheel (FL), front right wheel (FR), rear left wheel (RL), and rear right wheel (RR) sides of the vehicle, respectively.

The output side of the controller 22 is connected to the electric motor 4 of the compressor 3, the supply/exhaust valves 11, the intake solenoid valve 14, the return solenoid valve 16, the supply/exhaust switching valve 17, the exhaust solenoid valve 20, and the like on the FL side, FR side, RL side, and RR side. The Controller 22 is connected to another Controller (not shown) via a CAN (Controller Area Network) or the like, which is a Network required for data communication. Thus, the controller 22 can input and output various kinds of vehicle information including load information such as an outside air temperature (ambient temperature), date and time information, and a load weight between the controller and another controller.

The controller 22 includes a memory 22A including a ROM, a RAM, a nonvolatile memory, and the like. The memory 22A stores, for example, a program for executing the control process for vehicle height adjustment shown in fig. 3, a determination process map for determining whether or not the timing is to execute the regeneration process of the air dryer 7, and the like. That is, if the moisture adsorbent of the air dryer 7 is subjected to the regeneration treatment irregularly, the adsorbed moisture reaches a saturated state and the original function cannot be realized. Therefore, the memory 22A stores the time, the number of times, and the like of the outside air sucked by the compressor 3, and the controller 22 performs the determination process of the timing for performing the regeneration process of the air dryer 7 as in step 7 in fig. 3 by performing the mapping operation and the like based on the stored contents.

The controller 22 controls the driving of the electric motor 4 based on signals from the vehicle height sensors 23, the selector switch 24, and the like, outputs control signals to the supply/exhaust valves 11, the intake solenoid valve 14, the return solenoid valve 16, the supply/exhaust switching valve 17, the exhaust solenoid valve 20, and the like, and excites or demagnetizes the valves 11, 14, 16, 17, and 20 (specifically, the solenoids), respectively. Thereby, the supply/exhaust valve 11 is switched to any one of the illustrated closed position (a) and open position (b), and the intake solenoid valve 14, the return solenoid valve 16, the supply/exhaust switching valve 17, and the exhaust solenoid valve 20 are also switched to any positions.

The air suspension device of the first embodiment has the above-described configuration, and the operation thereof will be described by exemplifying a case where the selector switch 24 is operated so as to adjust the vehicle height in the automatic mode.

As shown in fig. 3, when the control process of the vehicle height adjustment by the controller 22 is started, the vehicle height is read in step 1 based on the detection signal from the vehicle height sensor 23. In the next step 2, it is determined whether or not the vehicle height at this time is lower than a set height (target height) based on the automatic mode. When it is determined as yes in step 2, the vehicle height raising control is executed in step 3 in such a manner that the vehicle height is raised to the set height.

Fig. 4 shows a specific example of the vehicle height raising control. That is, the controller 22 switches the intake solenoid valve 14 from the closed position (c) to the open position (d) to an open state, drives the compressor 3 by the electric motor 4, and switches the supply/exhaust valve 11 of the air suspension 1 to the open position (b). Fig. 4 illustrates a case where the vehicle height raising control is performed by the air suspensions 1 of all four wheels. This is merely a representative example, and a configuration may be adopted in which the vehicle height raising control is performed by at least one air suspension 1 among the air suspensions 1 of the four wheels.

By the switching control, the compressed air in the tank 12 flows out to the tank-side suction line 13 along the arrow in fig. 4, and is sucked from the intake side 3A in accordance with the operation of the compressor 3. The compressed air discharged from the discharge side 3B of the compressor 3 is supplied to the air chamber 1C of the air suspension 1 along the arrows in fig. 4 via the air dryer 7, the check valve 8B of the check throttle valve 8, and the supply/discharge switching valve 17. This enables the air suspension 1 to drive the vehicle height in the upward direction. Thus, when the vehicle height rises, the air compressed by the compressor 3 is dried by the air dryer 7, and the compressed air in a dry state is supplied into the air chamber 1C of the air suspension 1.

In this case, the compressor 3 can suck the compressed air stored in the tank 12 from the intake side 3A and generate high-pressure compressed air by the discharge side 3B, and can quickly supply the compressed air into the air chamber 1C of the air suspension 1. In other words, the compressor 3 can generate compressed air at a higher pressure by sucking compressed air in the tank 12 compressed in advance, not air at atmospheric pressure, and therefore, the pressure-increasing time of the compressed air can be shortened, and the air chamber 1C of the air suspension 1 can be extended (raised) early.

During this time, the compressed air in the tank 12 is sucked into the intake side 3A of the compressor 3, and therefore, the pressure in the tank 12 gradually decreases. In this state, even if the internal pressure of the tank 12 tends to be negative, the intake valve 9 (check valve) is automatically opened, and therefore the compression operation of the compressor 3 can be continued. That is, the intake valve 9 is set to be opened when the pressure on the connection point 5A side becomes atmospheric pressure or lower, for example, whereby the compressor 3 can take in air that is under-compressed from the intake port 5B and a necessary intake air amount is secured.

Therefore, the compressor 3 can take in air from the outside through the air intake port 5B and the intake pipe 5, and supply compressed air to the air chamber 1C of the air suspension 1 through the supply and discharge pipe 6, the air dryer 7, and the supply and discharge switching valve 17. In the state of the vehicle height raising control shown in fig. 4, even when the intake solenoid valve 14 is returned to the closed position (C) and closed, the compressor 3 can suck in air from the outside air through the intake port 5B and the intake pipe 5 and compress the air, and can supply the compressed air to the air chamber 1C of the air suspension 1 through the supply and discharge pipe 6, the air dryer 7, and the supply and discharge switching valve 17.

In the next step 4, the vehicle height is read based on the detection signal from the vehicle height sensor 23. In the next step 5, it is determined whether or not the vehicle height at that time has reached the target height (set height). If yes is determined in step 5, the vehicle height reaches the target set height, and therefore the vehicle height raising control is completed and the vehicle height adjustment process is ended. When it is determined as no in step 5, the process returns to step 2 and continues the subsequent processes.

On the other hand, if no is determined in step 2, the vehicle height is equal to or higher than the set height, and therefore, it is determined in the next step 6 whether the vehicle height is higher than the set height (target height). If it is determined as yes in step 6, the vehicle height is lowered by discharging compressed air from the air chamber 1C of the air suspension 1. Therefore, in the next step 7, it is determined whether or not it is the regeneration timing of the air dryer 7. If it is determined as no in step 7, since the regeneration process of the air dryer 7 is not required, the vehicle height lowering control is executed as shown in fig. 5 with the exhaust solenoid valve 20 closed in the next step 8.

In the vehicle height lowering control of fig. 5, the controller 22 switches the supply/exhaust valve 11 of the air suspension 1 from the closed position (a) to the open position (b) to the open state, switches the supply/exhaust switching valve 17 from the supply/exhaust position (g) to the return position (h), drives the compressor 3 by the electric motor 4, and switches the return solenoid valve 16 from the closed position (e) to the open position (f). Thereby, the compressed air in the air suspension 1 (the air chamber 1C) flows out from each branch pipe 10A (the air duct 10) to the return line 18 via the supply/discharge switching valve 17 as indicated by arrows shown in fig. 5, and is sucked from the intake side 3A in accordance with the operation of the compressor 3.

The compressed air discharged from the discharge side 3B of the compressor 3 is charged so as to be released into the tank 12 via the air dryer 7, the check valve 8B of the check throttle valve 8, the tank line 15, and the return solenoid valve 16. That is, the compressed air in the air suspension 1 (air chamber 1C) is forcibly discharged into the tank 12, whereby the air chamber 1C of the air suspension 1 can be reduced in size to lower the vehicle height.

Thereafter, the vehicle height is read in step 4 based on the detection signal from the vehicle height sensor 23, and it is determined whether the vehicle height at that time has reached the target vehicle height (set height) in step 5. If yes is determined in step 5, the vehicle height reaches the target set height, and therefore the vehicle height lowering control is completed and the process is ended. At this time, the electric motor 4 of the compressor 3 can be stopped from being driven to interrupt the compression operation. When it is determined as no in step 5, the process returns to step 2 and continues the subsequent processes.

On the other hand, if it is determined as yes in step 7, it is the timing at which the regeneration process of the air dryer 7 should be performed, and if the moisture adsorbent of the air dryer 7 is left as it is, the adsorbed moisture is saturated and the original function cannot be realized. Therefore, in the next step 9, the exhaust solenoid valve 20 is opened to perform the regeneration process of the air dryer 7, and the vehicle height lowering control is executed as shown in fig. 6.

In the vehicle height lowering control of fig. 6, the controller 22 switches the supply/exhaust valve 11 of the air suspension 1 from the closed position (a) to the open position (b) to the open state and switches the exhaust solenoid valve 20 from the closed position (i) to the open position (j) in a state where the supply/exhaust switching valve 17 is returned to the supply/exhaust position (g). At this time, the electric motor 4 of the compressor 3 is stopped to interrupt the compression operation.

As a result, the compressed air in the air suspension 1 (air chamber 1C) flows backward through the supply and discharge line 6 and the air dryer 7 from each branch pipe 10A (air duct 10) via the supply and discharge switching valve 17, and is directly discharged to the outside air from the exhaust port 19A via the exhaust line 19 and the exhaust solenoid valve 20, as indicated by arrows shown in fig. 6.

In this case, the check throttle valve 8 provided in the middle of the supply/discharge pipe 6 is in a state where the check valve 8B is closed, and the compressed air flowing backward along the arrow in fig. 6 is gradually flown backward at a small flow rate in the air dryer 7 because the flow rate is throttled by the throttle portion 8A. Therefore, when the compressed air (exhaust gas) discharged from the air suspension 1 (the air chamber 1C) flows in the reverse direction in the air dryer 7 (the supply/discharge pipe 6), the dried air flows backward in the air dryer 7, and therefore the moisture adsorbent in the air dryer 7 desorbs moisture by the dried air. Thereby, the moisture adsorbent of the air dryer 7 is regenerated, and the state is returned to the state capable of adsorbing moisture again.

That is, at this time, the compressed air discharged from the air suspension 1 (the air chamber 1C) flows back through the supply and discharge pipe 6 in the air dryer 7, and therefore the moisture adsorbent in the air dryer 7 is regenerated by passing the air dried by the air suspension 1 therethrough, and the air dryer 7 can be efficiently regenerated. This makes it possible to increase the vehicle height lowering speed when the vehicle height is lowered by reducing the air chamber 1C of the air suspension 1, and to realize the regeneration process of the air dryer 7 with high efficiency.

In this case, the vehicle height is also read in step 4, and when it is determined in step 5 that the vehicle height has reached the set height, the vehicle height lowering operation by the air suspension 1 is stopped, and the vehicle height adjustment process is ended. That is, when it is determined in step 5 that the target vehicle height is reached based on the detection signal from the vehicle height sensor 23, the controller 22 outputs a control signal to demagnetize the solenoid of the supply/exhaust valve 11 to end the vehicle height adjusting operation, and returns the supply/exhaust valve 11 to the closed position (a). Thus, the supply/discharge line 6 of the compressor 3 is cut off from the air chamber 1C of the air suspension 1, and therefore, the air suspension 1 operates as an air spring to maintain the target vehicle height, and can be maintained in a state in which the target vehicle height (set height) is maintained.

As described above, the air suspension device according to the first embodiment includes: a compressor 3 for compressing air; a tank 12 configured to store air; a tank-side intake line 13 (first path) for supplying the compressed air in the tank 12 to the intake side 3A of the compressor 3; a tank pipe line 15 (second passage) connecting the discharge side 3B of the compressor 3 to the tank 12; an air suspension 1 connected to the discharge side 3B of the compressor 3 via an air dryer 7; a first valve (intake solenoid valve 14) provided in the first passage (tank-side intake line 13); a second valve (return solenoid valve 16) provided in the second passage (tank pipe 15); and an exhaust line 19 (third line) branched from between the discharge side 3B of the compressor 3 and the air dryer 7 and connected to the atmosphere by opening an exhaust solenoid valve 20 (third valve), and the air dryer 7 can be regenerated by compressed air in the air suspension 1 by closing the first valve and the second valve and opening the third valve.

Therefore, by opening the exhaust solenoid valve 20 (third valve) with the intake solenoid valve 14 (first valve) and the return solenoid valve 16 (second valve) closed, compressed air can be discharged from the air suspension 1 to the atmosphere to regenerate the air dryer 7. When the pressure in the air suspension 1 is lower than the pressure in the tank 12, the air dryer 7 can be efficiently regenerated, and the regeneration frequency can be reduced. This can shorten the driving time of the compressor 3 in the dryer regeneration step.

Further, the intake solenoid valve 14 (first valve), the return solenoid valve 16 (second valve), and the exhaust solenoid valve 20 (third valve) provided between the compressor 3 and the tank 12 can be configured using, for example, an on/off type, inexpensive electromagnetic switching valve (two-way solenoid valve) having high versatility, and can be a low-cost system as compared with the conventional technique of patent document 1, for example. That is, in the conventional art, the intake side and the discharge side of the compressor are connected to the tank by a three-way solenoid valve.

In contrast, in the present embodiment, the intake side 3A and the discharge side 3B of the compressor 3 are connected to the tank 12 via an intake solenoid valve 14 and a return solenoid valve 16, which are constituted by on/off two-way solenoid valves, for example. Further, since the tank 12 is shut off from the compressor 3 and the air suspension 1 when the intake solenoid valve 14 and the return solenoid valve 16 are closed (in a demagnetized state of the solenoids), the risk of air leakage of the compressed air stored (accumulated) in the tank 12 is reliably reduced. This can reduce the number of times the compressor 3 compresses the outside air, and as a result, can reduce the frequency of regeneration by the air dryer 7.

Further, regardless of the pressure in the tank 12, the vehicle height can be adjusted by sucking the outside air by the compressor 3 and directly supplying the compressed air to the air suspension 1. Therefore, in a situation where the tank pressure is higher than the atmospheric pressure, the compressed air can be filled into the air suspension 1 in excess with the outside air, and the regeneration process of the air dryer 7 can be immediately performed from the air suspension 1, thereby creating a chance of regeneration of the air dryer 7.

Further, the air suspension device of the first embodiment can store compressed air after being compressed in the tank 12, and can realize a closed circuit (closed type) that can further compress the compressed air stored in the tank 12 by the compressor 3 and supply it to the air suspension 1. Further, the compressed air discharged from the air chamber 1C of the air suspension 1 can be returned to the atmosphere by the return solenoid valve 16 and stored in the tank 12 without being released to the atmosphere, and the compressed air can be effectively used without being discharged in a wasteful manner.

Further, in the air suspension device according to the first embodiment, since the compressor 3 sucks and compresses the compressed air in the tank 12, the frequency of sucking air from the outside atmosphere (i.e., the opening frequency of the intake valve 9) can be significantly reduced, and the frequency of occurrence of a problem due to dust and moisture sucked into the atmosphere can be reduced. Further, compared to the conventional closed type, it is not necessary to perform pressure control or the like using a pressure sensor or the like, and it is not necessary to perform complicated control, and the entire configuration can be simplified.

Therefore, according to the first embodiment, since the adsorption and regeneration of moisture by the air dryer 7 are appropriately performed, the saturation of the adsorbent can be prevented. In addition, a closed system that does not require complicated control by the controller 22 can be provided. Further, it is not necessary to use a plurality of three-way solenoid valves as in the conventional technique (patent document 1), and a low-cost system can be provided. As the intake/exhaust valve 11, the intake solenoid valve 14, the return solenoid valve 16, and the exhaust solenoid valve 20, on/off type electromagnetic switching valves (two-way solenoid valves) having high versatility can be used, and the number thereof can be minimized.

In the first embodiment, since the normal use range as the air suspension device is established in the closed loop system, the vehicle height rise time can be shortened when the vehicle is used at a high frequency. Only when the vehicle height adjustment range is larger than the normal use range, the air can be taken in (the intake valve 9 is opened) or the compressed air can be released to the atmosphere (the exhaust solenoid valve 20 is opened) as necessary.

In the first embodiment, as shown in fig. 2, the case where the pressure in the air chamber 1C or the tank 12 is detected by using the pressure detector 21 is described as an example. However, the present invention is not limited to this, and for example, a configuration may be adopted in which the pressure in the air chamber 1C or the tank 12 is estimated from the change in the vehicle height using the detection signal of the vehicle height sensor 23, and in this case, the pressure detector 21 may not be necessary.

Next, fig. 7 shows a second embodiment. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. However, the second embodiment is characterized by adopting the following structure: a first throttle portion having a larger throttle diameter than a second throttle portion is provided between the air dryer 7 and the fourth valve (the supply/discharge switching valve 17), and a second throttle portion is provided between the air dryer 7 and the second valve (the return solenoid valve 16).

That is, the first check throttle 31 employed in the second embodiment is disposed between the connection point 6B of the supply and discharge pipe 6 and the supply and discharge switching valve 17. The first check damper 31 is constituted by a parallel circuit of a throttle portion 31A and a check valve 31B, as with the check damper 8 described in the first embodiment. However, the throttle portion 31A in this case constitutes a first throttle portion provided in the middle of the supply and discharge pipe 6.

The second one-way throttle valve 32 employed in the second embodiment is disposed between the connection point 6B of the supply and discharge line 6 and the return solenoid valve 16 in the middle of the tank line 15 (second passage). The second check throttle 32 is constituted by a parallel circuit of a throttle portion 32A and a check valve 32B, as in the check throttle 8 described in the first embodiment. However, the throttle portion 32A in this case constitutes a second throttle portion provided in the middle of the tank pipe line 15 (second passage).

Here, the throttle diameter of the throttle portion 31A (first throttle portion) is larger than the throttle diameter of the throttle portion 32A (second throttle portion), and the amount of air flowing inside to regenerate the air dryer 7 is set so that the first throttle portion 31A has a relatively larger flow rate than the second throttle portion 32A. Thus, when the exhaust solenoid valve 20 is opened to discharge the compressed air from the air suspension 1 to the exhaust line 19 and control is performed to lower the vehicle height, the compressed air flows (flows backward) through the first throttle portion 31A of the first one-way throttle valve 31.

At this time, the first throttle unit 31A can adjust the flow rate of the air flowing from the air suspension 1 toward the exhaust line 19 to a desired flow rate and circulate the regeneration air (dry air) through the air dryer 7. Therefore, at the time of dryer regeneration by exhaust gas to the atmosphere, the air dryer 7 can be efficiently regenerated without reducing the vehicle height adjustment speed and without slowing down the lowering speed of the vehicle height.

On the other hand, in order to discharge the compressed air in the tank 12, the return solenoid valve 16 and the exhaust solenoid valve 20 are opened, and the compressed air may be discharged from the tank 12 toward the exhaust line 19. In this case, the compressed air in the tank 12 can be used as the air (dry air) for regenerating the air dryer 7 without adjusting the vehicle height (lowering the vehicle height). At this time, since the second throttle portion 32A of the second one-way throttle valve 32 is formed to have a smaller throttle diameter than the first throttle portion 31A, the flow of the compressed air can be slowed down to a small flow rate, and the air dryer 7 can be efficiently regenerated by the regeneration air (dry air) flowing from the tank 12 toward the exhaust line 19.

In the second embodiment thus configured, as in the first embodiment, the air leakage in the tank 12 can be suppressed, and the regeneration process of the air dryer 7 can be performed efficiently. In particular, in the second embodiment, the second throttle portion 32A of the second one-way throttle valve 32 is formed to have a smaller throttle diameter than the first throttle portion 31A, so that the air dryer 7 can be efficiently regenerated by the regeneration air (dry air) flowing from the tank 12 toward the exhaust line 19.

Next, fig. 8 shows a third embodiment. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. However, the third embodiment is characterized in that the supply/discharge line (fourth path) provided between the discharge side 3B of the compressor 3 and the supply/discharge switching valve 17 is configured by the first supply/discharge line 41 and the second supply/discharge line 42 connected in parallel with each other, and the third supply/discharge line 44 connected to either one of the first supply/discharge line 41 and the second supply/discharge line 42 via the direction switching valve 43.

Here, one end portions of the first supply/discharge pipe 41 and the second supply/discharge pipe 42 are branched or joined at a position of the connection point 45, and are connected so as to always communicate with the discharge side 3B of the compressor 3. The third supply/discharge line 44 is provided between the supply/discharge switching valve 17 and the direction switching valve 43 described in the first embodiment, and is connected to the tank line 15 at a position of a connection point 44A. The direction switching valve 43 is constituted by a 3-port 2-position electromagnetic direction switching valve (i.e., a three-way electromagnetic valve) as in the supply/discharge switching valve 17, and is switched between a first position (l) and a second position (m).

While the directional control valve 43 is in the first position (l), the first supply/discharge line 41 is connected to the third supply/discharge line 44, and the second supply/discharge line 42 is blocked from the third supply/discharge line 44. However, when the direction switching valve 43 is switched from the first position (l) to the second position (m), the first supply/discharge line 41 is blocked from the third supply/discharge line 44, and the second supply/discharge line 42 is connected to the third supply/discharge line 44.

The air dryer 7 and the one-way throttle valve 8 are not provided in the first supply/discharge line 41, and the air dryer 7 and the one-way throttle valve 8 are provided in the second supply/discharge line 42 between the connection point 45 and the direction switching valve 43. The exhaust line 19 as a third passage is connected to the first supply and discharge line 41 and the second supply and discharge line 42, for example, at the position of a connection point 45.

In the third embodiment configured as described above, when the compressor 3 sucks in outside air from the intake port 5B to generate compressed air, the direction switching valve 43 is switched from the first position (l) to the second position (m). Therefore, the first supply and discharge line 41 is blocked from the third supply and discharge line 44, and the second supply and discharge line 42 communicates with the third supply and discharge line 44. Thus, when the vehicle height is raised, the compressed air discharged from the compressor 3 is supplied in a dry state into the air chamber 1C of the air suspension 1 via the second supply/discharge line 42 (the air dryer 7, the one-way throttle valve 8) and the branch pipe 10A of the air duct 10.

Further, when the air dryer 7 is regenerated by the dry air in the air suspension 1 (air chamber 1C), the direction switching valve 43 is switched to the second position (m) and the dry air discharged from the air suspension 1 (air chamber 1C) can be caused to flow backward through the second supply/discharge pipe 42, the one-way throttle valve 8, and the air dryer 7 in a state where the exhaust solenoid valve 20 is opened, so that the regeneration process of the air dryer 7 can be performed by the dry compressed air, and the vehicle height can be reduced.

On the other hand, in the other vehicle height adjustment, in the state where the direction switching valve 43 is returned to the first position (l), compressed air flows out and in between the air suspension 1 (air chamber 1C) and the tank 12, and the compressor 3 is driven as necessary, whereby the compressed air can be circulated through the first supply and discharge line 41 without passing through the second supply and discharge line 42 (air dryer 7, one-way throttle valve 8), and the vehicle height can be raised or lowered. In this case, since the compressed air does not flow through the second supply/discharge line 42 (the air dryer 7 and the one-way throttle valve 8), the pressure loss can be reduced, the energy loss due to heat generation can be suppressed, and energy saving can be achieved.

In the third embodiment, as shown in fig. 8, the case where the pressure in the air chamber 1C or the tank 12 is detected by using the pressure detector 21 is described as an example. However, the present invention is not limited to this, and for example, a configuration may be adopted in which the pressure in the air chamber 1C or the tank 12 is estimated from the change in the vehicle height using the detection signal of the vehicle height sensor 23, and in this case, the pressure detector 21 is not necessary. This is also the same as for the second embodiment.

In the above embodiments, the case where the intake port 5B and the exhaust port 19A are provided separately from each other with respect to the compressor device 2 has been described as an example. However, the present invention is not limited to this, and for example, the front end side of the exhaust line 19 may be connected to an intake line (for example, between the intake valve 9 and the intake port 5B) to form an intake/exhaust port in which the intake port also serves as an exhaust port.

Next, the invention included in the above embodiment will be described. That is, according to a first aspect of the present invention, an air suspension device includes: a compressor that compresses air; a canister configured to store air; a first passage that supplies compressed air in the tank to a suction side of the compressor; a second passage connecting a discharge side of the compressor with the tank; an air suspension connected to a discharge side of the compressor via an air dryer; a first valve disposed in the first passage; a second valve disposed in the second passage; and a third passage provided to be branched from between a discharge side of the compressor and the air dryer, and connected to the atmosphere by opening a third valve, and the air dryer can be regenerated by compressed air in the air suspension by closing the first valve and the second valve and opening the third valve.

As a second aspect, in the first aspect, the compressed air compressed from the atmosphere is supplied to the air suspension without passing through the tank in response to a command from a control means. As a third mode, in the first mode, a fourth passage connecting the air dryer and the air suspension is provided, and a fourth valve is provided in the fourth passage.

As a fourth aspect, in the first aspect, a first throttle portion is provided between the air dryer and the fourth valve, and a second throttle portion is provided between the air dryer and the second valve, and a throttle diameter of the first throttle portion is larger than a throttle diameter of the second throttle portion. As a fifth aspect, in any one of the first to fourth aspects, the first valve and the second valve are two-way solenoid valves.

The present invention is not limited to the above embodiment, and includes various modifications. For example, the above embodiments have been described in detail to explain the present invention in an easily understandable manner, but the present invention is not limited to having all the configurations described above. Note that a part of the structure of one embodiment may be replaced with the structure of another embodiment, or the structure of one embodiment may be added to the structure of another embodiment. In addition, as for a part of the configuration of each embodiment, addition, deletion, and replacement of another configuration can be performed.

The present application claims priority from japanese patent application No. 2018-178847, filed on 25/9/2018. The entire disclosure including the specification, claims, drawings and abstract of japanese patent application No. 2018-178847, filed 2018, 9, 25, month and year is incorporated by reference into the present application in its entirety.

Description of the reference numerals

1 air suspension 2 compressor device 3 compressor 4 electric motor 5 intake line 6 to discharge line (fourth passage) 7 air dryer 8, 31, 32 one way throttle 8A throttle 9 intake valve 10 air conduit (fourth passage) 11 to exhaust valve 12 tank 13 tank side intake line (first passage) 14 intake solenoid valve (first valve) 15 tank side intake line (second passage) 16 return solenoid valve (second valve) 17 to discharge switching valve (fourth valve) 18 return line 19 exhaust line (third passage) 20 exhaust solenoid valve (third valve) 21 pressure detector 22 controller (control member) 23 vehicle height sensor 31A throttle (first throttle) 32A throttle (second throttle) 41 first to discharge line 42 second to discharge line 43 to switching valve 44 third to discharge line 44