JP2002166718A - Air spring device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a lowering phenomenon against an intention of an air spring device for a vehicle. SOLUTION: This air spring device for the vehicle is furnished with left and right air springs 3a, 3b, 4a, 4b to adjust vehicle height in reserving quantity of air from an air source 2, air passages 5, 6 to communicate the air source 2 and these air springs to each other, a main valve 11 to change introduction of air from the air source 2 and discharge of air of each of the air springs over to each other, an auxiliary valve 12 to open and close the air passage 5, an auxiliary valve 13 to open and close the air passage 6, solenoid valves 15, 16, 17 to supply and control pilot air pressure to change the main valve 11, the auxiliary valve 12, the auxiliary valve 13 and a high pressure preference valve 18 to introduce air from the air source 2 and the air passage 5 and to supply the air higher in pressure of these air to inlet ports of the solenoid valves 15, 16, 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air spring device for a vehicle, and more particularly to an air spring device for a vehicle capable of intentionally raising and lowering a vehicle height. It relates to a system that is effective for use in a suspension system.

[0002]

2. Description of the Related Art In general, large vehicles such as buses and trucks are equipped with an air suspension system. Such an air suspension system uses an air spring device for a vehicle that automatically adjusts the vehicle height. I have. That is, the vehicle air spring device includes an air spring that expands and contracts by supplying and discharging air, and the supply and discharge of air to and from the air spring interposed between the axle and the vehicle body are automatically adjusted by the solenoid valve. By doing
The cushion and the vehicle height are automatically adjusted.

[0003] As a conventional air spring device for a vehicle of this type, there is an air spring device configured so that the vehicle height can be adjusted intentionally by controlling the supply and discharge of air to and from the air spring by a solenoid valve. is there. For example, for convenience when passengers get on and off the route bus, the air of the left air spring is intentionally evacuated by controlling the solenoid valve to lower the vehicle height on the entrance side,
In order to eliminate the step with the platform when loading and unloading the cargo in the delivery truck, the air of the rear wheel side air spring is intentionally discharged by the control of the solenoid valve, so that the rear of the loading platform can be removed. Some are configured so that the vehicle height can be lowered.

[0004]

However, in an air spring device for a vehicle configured so that the vehicle height can be intentionally adjusted by controlling the electromagnetic valve, when air supply is commanded to the air spring by the electromagnetic valve. In addition, the vehicle height may fall against the driver's intention.

An object of the present invention is to provide an air spring device for a vehicle which can prevent the vehicle height from being reduced against the driver's intention.

[0006]

An air spring device for a vehicle according to the present invention comprises an air source for supplying compressed air and an air spring for adjusting the positions of the axle and the vehicle body by the amount of stored air from the air source. And an electromagnetic valve that is interposed in an air passage that guides air from the air source to the air spring and that switches the air passage in accordance with a command. A high-pressure priority shuttle valve for introducing air having a higher pressure out of the pressure and the pressure of the air on the air source side and applying the air to an inlet port of the solenoid valve is provided between the air spring and the air source. It is characterized by being connected between.

According to the above-mentioned means, the higher pressure air of the air spring side air pressure and the air source side air pressure is applied to the inlet port of the solenoid valve by the high pressure priority type shuttle valve. Even if the air pressure on the air source side is lower than the air pressure on the air spring side,
It is possible to prevent a phenomenon in which the vehicle height is lowered against the driver's intention.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

In the present embodiment, as shown in FIG. 1, the vehicle air spring device according to the present invention is applied to a rear system air suspension in a route bus, and is applied to a front system air suspension. Have been applied. However, since the mechanisms of the rear system and the front system are basically the same, illustration and description of the air suspension of the front system are omitted.

As shown in FIG. 1, a rear air suspension (hereinafter referred to as a suspension) 1 in a route bus has a pair of left and right air springs 3a.
And 3b, 4a and 4b, and these air springs 3a, 3b, 4a and 4b are interposed between the rear wheel axle and the vehicle body, respectively. The pair of left air springs 3a and 3b and the pair of right air springs 4a and 4b can separately adjust the position (vehicle height) between the vehicle body and the axle on the left and right in accordance with the amount of stored air. I have. That is, the pair of left air springs 3a, 3a
b is connected to the air source 2 via the left air passage 5, and the pair of right air springs 4 a, 4 b are connected to the air source 2 via the right air passage 6.

As shown in FIG. 1, a solenoid valve device 10 is connected between the left air passage 5 and the right air passage 6 and the air source 2 via a protection valve 7. The solenoid valve device 10 includes a main switching valve (hereinafter, referred to as a main valve) 11 composed of a 3-port 2-position pilot switching valve and a left and right sub-ports composed of a 2-port 2-position pilot switching valve. Switching valves (hereinafter referred to as auxiliary valves) 12 and 13 and three solenoid valves 15 and 1 each having a three-port, two-position and solenoid valve
6 and 17 and a high pressure priority type shuttle valve 18. The solenoids of the three solenoid valves 15, 16, 17 are configured to be controlled by a command from the controller 14, and the controller 14 includes vehicle height sensors 19A, 19
B is configured to automatically control the solenoid valve based on a detection signal such as B, and is configured to intentionally control the solenoid valve based on the operation of the manual switches 14a and 14b operated by the driver. I have. The switch 14a is a left-side down switch, and the switch 14b is a left-side up switch.

The main valve 11 has an inlet port 11a, an outlet port 11b, and an exhaust port 11c. An air source 2 is connected to the inlet port 11a via a protection valve 7, and right and left auxiliary ports are connected to the outlet port 11b. Valve 12, 1
The three inlet ports 12a and 13a are connected to each other, and the exhaust port 11c is open to the atmosphere. In the normal position, the inlet port 11a of the main valve 11 is closed, and the outlet port 11b is connected to the exhaust port 11c.

The left air passage 5 is connected to the outlet port 12b of the left auxiliary valve 12, and the left auxiliary valve 12 has the inlet port 12a and the outlet port 12b in the normal position.
And are in a closed state. The right air passage 6 is connected to the outlet port 13b of the right auxiliary valve 13,
The right auxiliary valve 13 is located at the inlet port 13 in the normal position.
a and the outlet port 13b are closed.

The first solenoid valve 15 has an inlet port 15a, an outlet port 15b, and an exhaust port 15c. The inlet port 15a is for the high pressure priority type shuttle valve 18, the outlet port 15b is for the pilot section of the main valve 11, and Exhaust port 15
c is respectively connected to the atmosphere. At the normal position, the first solenoid valve 15 has the inlet port 15a closed and the outlet port 15b connected to the exhaust port 15c. The second solenoid valve 16 has an inlet port 16a, an outlet port 16b, and an exhaust port 16c. The inlet port 16a is provided to the high-pressure priority type shuttle valve 18, the outlet port 16b is provided to the pilot portion of the left auxiliary valve 12, and the exhaust port is provided. 16c are each connected to the atmosphere. In the normal position, the second solenoid valve 16 has the inlet port 16a closed and the outlet port 16b connected to the exhaust port 16c. The third solenoid valve 17 has an inlet port 17a
, An outlet port 17b and an exhaust port 17c, and the inlet port 17a is connected to the high-pressure priority type shuttle valve 18,
The outlet port 17b is connected to a pilot portion of the right auxiliary valve 13,
The exhaust ports 17c are respectively connected to the atmosphere. The third solenoid valve 17 has the inlet port 17a in the normal position.
Is closed and the outlet port 17b is connected to the exhaust port 17c.

The high pressure priority type shuttle valve 18 has a first inlet port 18a, a second inlet port 18b, and an outlet port 18.
c, the first inlet port 18a is connected to the air source 2 via the protection valve 7, the second inlet port 18b is connected to the left air passage 5, and the outlet port 18
c is the inlet port 15 of the three solenoid valves 15, 16, 17
a, 16a and 17a. The high pressure priority shuttle valve 18 has a first inlet port 18a and a second inlet port 1
8b, the higher pressure air is supplied to the outlet port 18c.

Next, the operation of the suspension according to the above configuration will be described mainly on the operation of the electromagnetic valve device 10.

Three solenoid valves 1 of the solenoid valve device 10
When the controller 5, 14, 17 is demagnetized by the controller 14, the main valve 11 and the left and right auxiliary valves 12, 13 are in the state shown in FIG. 1, so that the left and right air springs 3a, 3b, 4a 4b maintain a normal vehicle height state.

For example, when the driver turns on the left lowering switch 14a of the controller 14 to lower only the left air springs 3a and 3b when the passenger gets on and off, as shown in FIG. The second solenoid valve 16 of the three solenoid valves 15, 16, 17 is switched by being excited by the controller 14. Then, since the inlet port 16a is connected to the outlet port 16b, the left auxiliary valve 12 is switched to a position connecting the inlet port 12a and the outlet port 12b.
The air in the left air springs 3a and 3b is
2 through the exhaust port 11c of the main valve 11. As a result, the amount of stored air in the left air springs 3a, 3b decreases, and only the left vehicle height decreases.

The decrease in the vehicle height on the left side is detected by a left vehicle height sensor 19A for detecting the distance between the left side of the axle and the vehicle body, and transmitted to the controller 14 as an electric signal. When the detection signal from the left vehicle height sensor reaches a predetermined left vehicle height value, the controller 14 demagnetizes the second solenoid valve 16 and switches to the original state shown in FIG. When the second electromagnetic valve 16 is switched to the original state, the air in the pilot path of the left auxiliary valve 12 is exhausted through the second electric switching valve 16, so that the left auxiliary valve 12 is closed. The vehicle height of the left air springs 3a, 3b is maintained at the value of the lowered vehicle height.

In order to return the lowered vehicle height to the original state after the passenger has been lifted and lowered, the driver operates the left air springs 3a and 3b to restore the vehicle height to the left raising switch 14.
When the controller 14 is commanded by turning on b, as shown in FIG. 3, the first solenoid valve 15 of the three solenoid valves 15, 16, 17 of the solenoid valve device 10 and the second solenoid valve The valve 16 and the controller 16 are simultaneously energized and switched by the controller 14. That is, the inlet port 15a of the first solenoid valve 15 is connected to the outlet port 15b, and the inlet port 16a of the second solenoid valve 16 is connected to the outlet port 16b. Thereby, the main valve 11 and the left auxiliary valve 12
, The main valve 11 and the left auxiliary valve 12 are respectively switched to the communicating positions, and air from the air source 2 is supplied to the left air springs 3a and 3b by the main valve 11 and the left auxiliary valve. 12 is provided. As a result, the left air springs 3a, 3
The amount of stored air in b increases, and only the vehicle height on the left increases.

The increase in the vehicle height on the left side is detected by a left vehicle height sensor 19A for detecting the distance between the left side of the axle and the vehicle body, and transmitted to the controller 14 as an electric signal. When the vehicle height on the left side based on the detection signal from the vehicle height sensor 19A reaches a predetermined vehicle height value on the left side, the controller 14 demagnetizes the first solenoid valve 15 and the second solenoid valve 16 and returns to the original position shown in FIG. Switch to the state of. When the first solenoid valve 15 and the second solenoid valve 16 switch to the original state,
The main valve 11 and the left auxiliary valve 12 are respectively switched to the original closed positions. When the left auxiliary valve 12 is switched to the closed position, the left auxiliary valve 12 closes the left air passage 5, so that the vehicle height of the left air springs 3a and 3b is set to a predetermined vehicle height during traveling. It will be maintained.

By the way, when the vehicle height of the left air springs 3a, 3b intended by the driver is restored after the vehicle height of the left air springs 3a, 3b intended by the driver is reduced, the pressure is accumulated in the left air passage 5. Main valve 1 over pressure
If the pilot pressure applied to port 1 is low,
When the air supply operation for supplying the air from the outlet port 1a to the outlet port 11b is performed, as shown in FIG.
However, the main valve 11 is pushed back by the air pressure in the passage 5A to connect the outlet port 11b and the exhaust port 11c. The exhaust operation may be performed during the air supply operation. When the exhaust operation is performed in spite of the command of the air supply operation as described above, the vehicle height may be reduced when the vehicle height is to be increased, so that it may be determined that the driver has failed. .

In the present embodiment, the solenoid valve device 10
The inlet ports 15a of the three solenoid valves 15, 16, 17
Since the high pressure priority type shuttle valve 18 for supplying pilot pressure to 16a and 17a is connected between the left air passage 5 and the inlet port 11a of the main valve 11, the main pressure is higher than the pressure accumulated in the left air passage 5. When the pilot pressure applied to the valve 11 is low, the pilot pressure for operating the main valve 11 is the air pressure on the side of the air springs 3a and 3b, so that the main valve 11 is not pushed back. It is possible to prevent a situation in which the exhaust operation is performed despite the air supply operation.

That is, if the pilot pressure applied to the main valve 11 is lower than the pressure in the left air passage 5, the high pressure priority type shuttle valve 18 switches as shown in FIG. The pressure of a certain left air passage 5 is changed from the outlet port 18c of the high-pressure priority type shuttle valve 18 to the inlet ports 15a, 16 of the three solenoid valves 15, 16, 17.
Since the voltage is applied to the a and 17a, the main valve 11 and the auxiliary valve 12 on the left side reliably perform the air supply operation. as a result,
When the vehicle height of the left air springs 3a, 3b intended by the driver is restored after the driver lowers the vehicle height of the left air springs 3a, 3b, the vehicle height of the left air springs 3a, 3b is reduced. The driver does not judge that the vehicle is out of order because the vehicle does not fall unintentionally. Further, if the driver feels a delay in the recovery operation of the left air springs 3a, 3b, the driver will be aware that the pressure of the air source 2 has decreased. Processing such as activating the compressor and waiting for an increase in the air pressure of the air source can be taken.

As described above, according to the present embodiment, it is possible to prevent a phenomenon that the vehicle height is lowered against the driver's intention, so that it is possible to prevent the driver from determining that the vehicle is out of order. Can be prevented. In addition, since it is only necessary to provide a high-pressure priority type shuttle valve, manufacturing costs and running costs are lower than when a computer detects a phenomenon in which the vehicle height drops unintentionally and prevents it. Can be greatly reduced.

The present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the scope of the present invention.

For example, the high-pressure priority type shuttle valve is not limited to being connected to the left communication passage, but may be connected to the right communication passage, or may be connected to both the left communication passage and the right communication passage.

The high-pressure priority shuttle valve is not limited to being connected to the external pilot type, but may be connected to the internal pilot type. Further, the protection valve 7 may be a check valve.

In the above embodiment, the case where the left and right air springs are operated has been described. However, the present invention can also be applied to the case where the front air spring and the rear air spring are operated.

[0030]

As described above, according to the present invention,
The operation against the intention of the vehicle height can be prevented.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a suspension according to an embodiment of the present invention.

FIG. 2 is a circuit diagram illustrating a lowering operation of a left air spring.

FIG. 3 is a circuit diagram showing the time of the recovery operation.

FIG. 4 is a circuit diagram showing a conventional suspension.

[Explanation of symbols]

1. Suspension (vehicle air spring device),
1 ': conventional suspension, 2: air source, 2A: air passage from air source, 3a, 3b: left air spring,
4a, 4b right air spring, 5 left air passage,
5A: air passage between main valve and auxiliary valve, 6: right air passage, 7: protection valve, 10: solenoid valve device, 1
0 ': conventional solenoid valve device, 11: main valve (main switching valve), 11a: inlet port, 11b: outlet port, 11
c: exhaust port, 12: left auxiliary valve (left sub switching valve), 12a: inlet port, 12b: outlet port, 13
... right auxiliary valve (right sub switching valve), 13a ... inlet port, 13b ... outlet port, 14 ... controller, 14a
… Left switch, 14b… left switch, 1
5, 16, 17: solenoid valve, 15a, 16a, 17a: inlet port, 15b, 16b, 17b: outlet port, 15
c, 16c, 17c: exhaust port, 18: high pressure priority type shuttle valve, 18a: first inlet port, 18b: second inlet port, 18c: outlet port, 19A, 19B: vehicle height sensor, 20A, 20B: wiring.

Claims (1)

[Claims] 1. An air source for supplying compressed air, an air spring for adjusting a position of an axle and a vehicle body by an amount of stored air from the air source, and air for guiding air from the air source to the air spring. A solenoid valve interposed in the passage for switching the air passage in accordance with a command, wherein the air pressure of the air on the air spring side and the air pressure on the air source side are higher. A high-pressure priority type shuttle valve for introducing one air and applying the air to an inlet port of the solenoid valve is connected between the air spring and the air source. apparatus.