JPH10217734A - Car height adjusting device for air suspension vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a car height adjusting device which can perform a kneeling action quickly and also can raise the height to be higher than a standard height in normal traveling in a low floor type air suspension vehicle. SOLUTION: This device is provided with leveling valves which are placed in an air passage 9 connecting air springs and air supply source to adjust air supply to the springs, electromagnetic exhaust valves 27, 28, and 29 to exhaust air from the air springs without passing through leveling valves when lowering a car height from a standard height, and electromagnetic supply valves 24, 25, and 26 supplying air to air springs without passing through leveling valves when returning a lowered car height to a standard height. An air suspension vehicle 1 carries out lowering/returning adjustment of a car height by opening and closing electromagnetic valves for exhaust and for air supply. The vehicle is provided with electromagnetic valves 30, 31, and 32 for car height raising which open and close an air passage connecting leveling valves and the electromagnetic exhaust valves, car height detection means 22 and 23 to detect the height of a car body 2, electromagnetic valves 30-32 for car height raising to be used in car height adjustment, and a control means 38 to drive and control electromagnetic valves 24-29 for exhaust and air supply based on car height information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle height adjusting device for a vehicle equipped with an air suspension, and more particularly to a vehicle height adjusting device used for a vehicle such as a bus capable of performing a kneeling operation for lowering the vehicle height of a vehicle body at a doorway. Related to the device.

[0002]

2. Description of the Related Art An air suspension used for a vehicle such as a bus is provided with a leveling valve for maintaining a constant vehicle height between an air spring and an air supply source for supplying air to the air spring. I have. The main body of the leveling valve is fixed to the frame side of the vehicle body, and the swinging lever that drives the valve is fixed to the axle side via a connecting rod, and the leveling valve depends on the distance between the lower surface of the frame and each axle. It operates to supply air to the air spring and discharge air from the spring to keep the vehicle height constant. In a bus equipped with such a leveling valve, an air cylinder that changes the length of the connecting rod is interposed on the connecting rod, and the air cylinder is driven to contract the connecting rod, so that the leveling valve is used when the vehicle body is raised in appearance. There is known a vehicle height adjusting device having a kneeling function of operating a vehicle and discharging air in an air spring into the atmosphere via a leveling valve to lower the entrance / exit side of the vehicle body.

For example, in Japanese Patent Application Laid-Open No. Hei 5-193330, an exhaust solenoid valve having an exhaust port is provided between a leveling valve and an air spring, and an air supply source is provided between the exhaust solenoid valve and the air spring. An air supply solenoid valve that supplies air to a level link valve or an air spring is provided, and air from the air spring is exhausted by an exhaust solenoid valve without passing through the leveling valve when adjusting the vehicle height to reduce the vehicle height. There has been proposed a vehicle height adjustment device that supplies air from an air supply source to an air spring by an air supply solenoid valve without passing through a leveling valve at the time of high return adjustment, thereby speeding up a kneeling operation and a return operation thereof.

[0004]

As a vehicle for getting passengers on and off such as a bus, a low-floor type in which the floor of the vehicle is lowered in consideration of the getting on and off of passengers has been put to practical use. In such a low-floor type bus, the height from the ground to the floor is reduced by changing the shape of the axle supporting the axle, the shape of the suspension, etc., and the minimum ground clearance is lower than that of ordinary vehicles. It is very low.

[0005] When an air suspension having a kneeling function is adopted for a low-floor type bus as described above, an approach angle and a departure angle are smaller than those of a general bus.
When passing through a place having a stepped portion such as a hill or a curb, the vehicle body may be caught. For this reason, it is required to make the vehicle height higher than the reference vehicle height during normal traveling when passing through such a stepped portion.

[0006] In the case of an air suspension vehicle having a high reference vehicle height and a knee link function instead of a low floor type, there is ample space under the floor. It is easy to make the vehicle height higher than the vehicle height. However, in the case of a low-floor type air suspension vehicle with a kneeling mechanism, the clearance between the vehicle body and the axle, which is the space under the floor, is very narrow, so the connecting rod length of the leveling valve cannot be increased, and the standard vehicle height during normal driving There is a problem that it is difficult to increase the vehicle height. SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicle height adjusting device for a low-floor type air suspension vehicle, which can perform a kneeling operation quickly and can make the vehicle height higher than a reference vehicle height during ordinary driving.

[0007]

SUMMARY OF THE INVENTION Therefore, a vehicle height adjusting apparatus for an air suspension vehicle according to the present invention comprises an air spring provided between a vehicle body and each axle disposed in front and rear of the vehicle body; It is provided on an air passage connecting a supply source, and is interposed between the vehicle body and the axle side to adjust air supply to the air spring in accordance with a relative displacement of an interval between the vehicle body and the axle side. A leveling valve, an exhaust solenoid valve for exhausting air from the air spring without passing through the leveling valve when lowering the vehicle body from a reference vehicle height, and a return adjustment for returning the lowered vehicle body to the reference vehicle height. Sometimes having an air supply solenoid valve for supplying air from the air supply source to the air spring without passing through the leveling valve, the exhaust solenoid valve and the air supply solenoid valve An air suspension vehicle that is closed to adjust the vehicle height of the vehicle body and adjusts the height of the vehicle body. The vehicle height increasing electromagnetic valve is provided in an air passage connecting the leveling valve and the exhaust electromagnetic valve, and opens and closes the air passage. Vehicle height detecting means for detecting the height of the vehicle body, vehicle height information from the vehicle height detecting means, and the exhaust solenoid valve, the supply air solenoid valve, and the vehicle height increasing solenoid valve. When the vehicle height is adjusted including the vehicle height reduction / return adjustment, the exhaust solenoid valve, the air supply solenoid valve, and the vehicle are connected based on a signal from the vehicle height detection means. Control means for controlling the drive of the high-up solenoid valve. As a result, the exhaust solenoid valve and the air supply solenoid valve are driven and controlled by the control means based on the vehicle height information to supply and exhaust air to and from the air spring without passing through the leveling valve. When the vehicle goes up, the leveling valve and the exhaust solenoid valve are placed between the leveling valve and the exhaust solenoid valve to close and close the leveling valve and the exhaust solenoid valve. Get done quickly without.

According to the second aspect of the present invention, a vehicle speed detecting means for detecting a vehicle speed of the vehicle body is electrically connected to the control means, and when the vehicle speed detected by the vehicle speed detecting means is equal to or less than a set vehicle speed, the vehicle speed is reduced. When the vehicle speed is higher than the set vehicle speed, the vehicle height up mode is not performed, so the load applied to the air spring due to the speed increase is suppressed, and the load on the air spring is reduced. Can be reduced and the suspension can be protected.

According to the third aspect of the present invention, a rear leveling valve for controlling air supply to an air spring on a rear axle side is connected to the axle side by an air cylinder connected to the air supply source via a control valve. The control valve is connected to the air supply source and the air cylinder is controlled by the vehicle control means based on a signal from the vehicle height detection means at the time of adjusting the vehicle height from a reference vehicle height. Therefore, air is supplied to the air cylinder depending on the state of the vehicle height at the time of adjusting the vehicle height, so that the leveling valve functions only when air is supplied to the air cylinder. For this reason, even if the vehicle height fluctuates due to the load fluctuation applied to the vehicle body during the vehicle height reduction adjustment, the leveling valve operates to keep the vehicle height at a constant height. The vehicle height at the time is kept constant.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle 1 indicated by reference numeral 1 in FIG. 1 has a chassis frame 3 serving as a base of a vehicle body 2, an axle portion 4 on a front axle side disposed on the front and rear sides of the vehicle body 1, and a rear wheel. A low-floor type bus is narrow between the wheel-side axle unit 5 and a left / right entrance 1A. Left and right air springs 6 for the front wheel are provided on both sides of the front wheel axle portion 4, and a pair of rear wheel air springs 7 and 8 are provided on both sides of the rear wheel axle portion 5.

As shown in FIG. 2, the left and right air springs 6 are connected to an air tank 12 serving as an air supply source through an air passage 9 formed by a connection pipe.
Reference numeral 8 is connected to an air tank 12 through air passages 10 and 11 formed by connecting pipes. In the air tank 12,
Air is supplied from a main tank 13 constituting an air supply source for accumulating air sent by a compressor (not shown) via a discharge portion 14 with a safety valve. Air tank 12
Is provided with a pressure sensor 15 for sending pressure information of the air tank 12 to a control means described later.

The air passages 9, 10, 11 are provided with leveling valves 16, 17, 18, respectively. The leveling valves 16 and 17 are, as shown in FIG.
6a, 17a are fixed to the chassis frame 3 on the vehicle body side, and swing levers 16b, 17b for switching the flow path in the valve body are connected to the upper portions of the axle portions 4, 5 via connecting rods 19, 20. ing. The leveling valve 18 has a valve body 18 a fixed to the chassis frame 3 and a swing lever 18 b for switching a flow path in the valve body being connected to the rod 2 of the air cylinder 21.
The axle part 5 is connected to the upper part via 1a. When the vehicle height is at the reference vehicle height, the swinging levers become horizontal and the leveling valves 16, 17, and 18 become horizontal.
7d and 18d are closed, and when the vehicle height decreases, the respective swing levers are lifted up to supply passages 16e, 17e and 18e.
When the vehicle height rises, the respective swinging levers are lowered, and their exhaust ports 16c, 17c, 18c are opened to the atmosphere. That is, each leveling valve opens and closes in accordance with the distance between the lower surface of the chassis frame 3 and the axle portions 4 and 5 to supply air to the air springs 6, 7 and 8, and to supply air to the air springs 6, 7 and 8. To maintain the vehicle height constant, and adjust the air supply to the air springs 6, 7, and 8 according to the relative displacement of the space between the vehicle body 2 and the axle side. .

The air cylinder 21 is set such that the rod 21a is maintained in an extended state in a normal case where air is not supplied, and the swing lever 18b is set in a horizontal state. Then, the rod 21a is contracted to lower the swing lever 18b.

Axles 4 and 5 shown in FIG.
A vehicle height sensor 22 on the front side and a vehicle height sensor 23 on the rear side for detecting the vehicle height of the vehicle are provided. Vehicle height sensor 22, 2
In 3, a change in vehicle height is detected by movement of a rod having one end supported on axle portions 4 and 5. Each vehicle height sensor 22, 2
Reference numeral 3 is arranged on the left side of the vehicle body.

The air tank 12 and the leveling valve 16,
In the air passage 9 between the air supply 17 and the air supply solenoid valve 2,
4, 25, 26 are leveling valves 16, 17, 18
Exhaust electromagnetic valves 27, 28, 29 are interposed in the air passage 9 between the air springs 6, 7, 8 respectively. Air passages 9A, 10A, 11 connecting the leveling valves 16, 17, 18 to the exhaust solenoid valves 27, 28, 29
A is equipped with electromagnetic valves 30, 31, 32 for increasing the vehicle height. Solenoid valves for increasing vehicle height 30, 31, 3
Reference numeral 2 denotes a two-way valve that opens and closes the air passages 9A, 10A, and 11A. The two-way valve is opened when turned off and closed when turned on.

The air supply solenoid valves 24, 25, and 26 are three-way solenoid valves, and have a second connection port 24b, 25b, 26b and a third connection port.
The connection ports 24c, 25c, 26c are connected to the air passages 9, 10, 1
1 respectively, and the first connection ports 24a, 25a, 26
a with air springs 6, 7, 8 and solenoid valves 27, 2 for exhaust
The air passages 9B, 10B, and 11B are connected to the air passages 9B, 10B, and 11B via branch passages 33, 33, and 35, respectively.

When the air supply solenoid valves 24, 25 and 26 are turned off, the second connection ports 24b, 25b and 26b and the third connection port 2
4c, 25c, and 26c to communicate with the air from the air tank 12 and the leveling valves 16, 17, 1.
8 and the second connection ports 24b, 25b, 26
b and the first connection ports 24a, 25a, 26a are in communication with each other, so that the air from the air tank 12 does not pass through the leveling valves 16, 17, 18 and the air springs 6,
7, 8 are supplied.

The exhaust solenoid valves 27, 28, 29 are three-way solenoid valves. The second connection ports 27b, 28b, 29b are connected to the air passages 9A, 10A, 11A, and the third connection ports 27c, 28.
c, 29c are connected to the air passages 9B, 10B, 11B, respectively, and the first connection ports 27a, 28a, 29a are air discharge ports.

When each of the exhaust solenoid valves 27, 28, 29 is off, the second connection ports 27b, 28b, 29b and the third connection port 2
7c, 28c, and 29c, and the third connection ports 27c, 28c, and 29c and the first connection port 27
a, 28a, and 29a, and air is exhausted from each air spring without passing through the leveling valves 16, 17, 18.

The air cylinder 21 has a cylinder air passage 3
6 is connected to the main tank 13. An electromagnetic valve 37 is provided in the cylinder air passage 36. Solenoid valve 37
Is a three-way valve that connects the second connection port 37b and the third connection port 37c to the cylinder air passage 36b, respectively.
7a is an air outlet. The solenoid valve 37 communicates with the first connection port 37a and the third connection port 37c when turned off, cuts off the supply of air from the main tank 13 to the air cylinder 21 and discharges air from the air cylinder 21. 2
The air is supplied to the air cylinder 21 by connecting the connection port 37b and the third connection port 37c, and the air cylinder 21 is contracted.

The supply air solenoid valves 24, 25, 26, the exhaust solenoid valves 27, 28, 29 and the vehicle height increase solenoid valves 30, 3
1 and 32 are electrically connected to the control means 38 shown in FIG. 3, and are driven and controlled by the control means 38, respectively.

The control means 38 mainly comprises a vehicle height adjustment control section 38a and a buzzer / lamp control section 38b.
The vehicle height adjustment control unit 38a is composed of a well-known microcomputer, and includes a vehicle height up mode in which the vehicle height is raised from the reference vehicle height T, a kneeling mode in which the vehicle body 2 is inclined toward the entrance 1A, and the like during normal running. Are set individually, and the vehicle height is adjusted by selecting each mode. The vehicle height adjustment control unit 38a includes the vehicle body 2 in addition to the pressure sensor 15 and the vehicle height sensors 22 and 23 described above.
A speed sensor 41 for detecting the speed of the engine, an alternator switch 42 for outputting an ON signal when the engine is rotating to detect the engine rotational state, and an ON operation when selecting each mode set in the control means 38 The vehicle height up switch 43 and the kneeling switch 44 are electrically connected.

In the control means 38, signals from the respective sensors and switches are input to a vehicle height adjustment control section 38a, in which vehicle height sensors 22, 23, a vehicle height up switch 43,
The signal from the kneeling switch 44 is also input to the buzzer / lamp control unit 38b.

In the vehicle height adjustment control unit 38a, when one of the vehicle height up switch 43 and the kneeling switch 44 is turned on, a mode corresponding to each switch is performed. An operation program for executing each mode and the supply air solenoid valves 24 and 2 are provided in the vehicle height adjustment control unit 38a.
The control vehicle heights T1, T2 and the vehicle speed V used for controlling the electromagnetic valves 5, 26, the exhaust electromagnetic valves 27, 28, 29 and the vehicle height increasing electromagnetic valves 30, 31, 32 are stored. The set vehicle heights T1 and T2 are set in a relationship of T1 <T <T2.

In the vehicle height adjustment control section 38a, during the kneeling process in the kneeling mode, the exhaust electromagnetic valves 27 and 29 are turned on until the vehicle height reaches the set vehicle height T1, and the electromagnetic valve 37 is turned on. When driven, the rod 21a of the air cylinder 21 is contracted, and the air supply solenoid valves 24 and 26 are turned on until the reference vehicle height T is reached at the time of the return to the kneeling. When the vehicle height is increased in the vehicle height increasing mode, the air supply solenoid valves 24, 25, and 26 are turned on until the vehicle body 2 reaches the set vehicle height T2.
0, 31, 32 are kept in the ON state, and the exhaust solenoid valves 27, 28, 29 are set to the reference vehicle height T when the vehicle height is restored.
Is controlled to be in the ON state until the state becomes.

The buzzer / lamp control section 38b executes a buzzer sound processing operation and a lamp display processing operation according to a stored program, and sets a sound operation state of a buzzer 46 connected to the buzzer / lamp control section 38b, The lighting state of the vehicle height up mode lamp 47, the kneeling mode lamp 48, and the diagnosis lamp 49 is controlled.

When the buzzer / lamp control unit 38b receives a buzzer sounding instruction output from the vehicle height adjustment control unit 38a before the vehicle height adjustment operation, the buzzer 46 sounds for a predetermined time and the vehicle sounds during the vehicle height adjustment. High adjustment notification function, exhaust solenoid valves 27, 28, 29 and air supply solenoid valves 24, 25, 26
And solenoid valves 30, 31, 32 for increasing vehicle height and solenoid valve 3
7, a failure display function of turning on the diagnosis lamp 50 when receiving a diagnosis lamp lighting command output from the vehicle height adjustment control unit 38a in accordance with the failure detection;
Lamps 47 and 4 corresponding to each mode during operation of each mode
8 is provided with a mode display function for lighting.

Next, the basic operation of the vehicle height adjusting device and the vehicle height adjusting operation by the control means 38 will be described in order. As shown in FIG. 4, during normal running, no special valve control is performed by the operation control means 38, and the supply electromagnetic valves 24, 25, 26, the exhaust electromagnetic valves 27, 28, 29, and the vehicle height increasing electromagnetic valve. 3
0, 31, and 32 are in the off state. For this reason,
The air from the air tank 12 is supplied to the leveling valve 16,
Since the air is supplied to the air cylinders 17 and 18 and the air is not supplied to the air cylinders 21 and becomes inactive, the leveling valves 16, 17 and 18 respectively function even when the vehicle height changes during normal running, and the vehicle body 2 It is held at the reference vehicle height T.

(Kneeling mode) When the kneeling switch 44 is turned on, the kneeling mode of the vehicle height adjustment controller 38a is selected, and the kneeling process and the kneeling return process are executed according to the flowcharts of FIGS. Is done.

When the kneeling switch 45 is turned on in step A1 of FIG.
The vehicle speed is determined based on the vehicle speed information of the vehicle speed sensor 41. If the vehicle speed is 0, the alternator switch 42 is switched in step A3.
Is determined, and if an engine (not shown) is rotating and there is an ON signal, the pressure in the air tank 12 is determined in step A4. If the tank internal pressure exceeds the predetermined pressure, it is determined in step A5 whether or not the engine is in a kneeling state. If the tank internal pressure has not reached the predetermined pressure, the process waits until the tank internal pressure reaches the predetermined pressure.
If it is not the kneeling state in step A5, step A6
Proceed to. That is, during steps A1 to A5, the state of the vehicle body 2 capable of kneeling is determined. When all the conditions (steps A1 to A5) are cleared, the state of the vehicle body 2 capable of kneeling is determined.
If no step has been cleared, the process returns to step 6 assuming that the vehicle body 2 has not been placed in a state where kneeling is possible.

In step A6, the exhaust solenoid valves 27, 2
It is determined whether or not the solenoid valve 9 and the solenoid valve 37 are normal. If there is no abnormality, a buzzer sounding command is outputted in step A7, and if abnormal, a diagnosis lighting command is outputted in step A10 and the routine returns. Buzzer 4 according to the instruction in step A7
6, the exhaust solenoid valves 27 and 29 and the solenoid valve 37 are connected to the steps A8 and A8, respectively, as shown in FIG.
It is turned on until the set vehicle height T1 is reached in A9.

When the exhaust solenoid valves 27 and 29 are turned on, the first connection ports 27a and 29a and the third connection port paths 27c and 29c of each valve communicate with each other in FIG. 2, and the leveling valves 16 and 18 and the air springs are connected. Air passages 9 between 6,8,
11 is shut off. In addition, each air supply solenoid valve 24, 25,
Since 26 is in the off state, the branch passages 33 and 35 are shielded. Therefore, the air in the air springs 6 and 8 is supplied from the exhaust solenoid valves 27 and 29 to the leveling valves 16 and
Since it is discharged without passing through 18, the kneeling is performed in a short time.

When the solenoid valve 37 is turned on, the second connection port 37b and the third connection port 37c communicate with each other to supply air from the main tank 13 to the air cylinder 21. When air is supplied to the air cylinder 21, the rod 21a contracts and the swing lever 18b of the leveling valve 18 moves downward from the horizontal state. However, since the vehicle body 2 has been lowered by the kneeling process, the swing is substantially shaken. The moving lever 18b is in a horizontal state. If there is a load change due to a change in the number of occupants during kneeling, the swing lever 18b swings according to the load. However, since air is supplied to the air cylinder 21, the swing lever 18b is in a horizontal state. To stabilize the vehicle height during kneeling.

A kneeling return process for returning from the kneeling state to the reference vehicle height T will be described with reference to a flowchart shown in FIG. This processing is performed when the kneeling switch 44 is turned off, or when the vehicle speed information of the vehicle speed sensor 41 detects a predetermined speed or more. That is, it is determined whether or not the kneeling switch 44 is off in step B1 of FIG. 6, and if not, it is determined in step B2 whether or not the vehicle speed information of the vehicle speed sensor 41 is equal to or lower than a predetermined speed.
If the speed is equal to or lower than the predetermined speed, the process returns.

Based on these determinations, the kneeling switch 44
If any of the information at or above the predetermined speed of the vehicle speed sensor 41 is detected, it is determined in step B3 whether or not the vehicle is in a kneeling state. If the vehicle is in the kneeling state, the air supply solenoid valves 24 and 26 are activated in step B4. It is determined whether it is normal or not. If there is no abnormality, a buzzer sounding command is output in step B5, and if abnormal, a diagnosis lighting instruction is output in step B7 and the routine returns. When the sounding time of the buzzer 46 elapses in accordance with the command in step B5, the air supply solenoid valves 24 and 26 are turned on until the reference vehicle height T is reached in step B6 as shown in FIG.

When the air supply solenoid valves 24 and 26 are turned on, the air from the air tank 12 is supplied to the air springs 6 and 8 via the air passages 33 and 35. On the other hand, the exhaust solenoid valves 27 and 29 and the vehicle height increasing solenoid valve 3
0, 32 are in the off state, so that the air passage 9
A, 9B and 10A, 10B are in a communicating state, and the belling valves 16, 18 perform a belling rig operation so as to reach the reference vehicle height T.

(Vehicle Height Up Mode) When the vehicle height up switch 43 is turned on, the vehicle height up mode of the vehicle height adjustment control unit 38a is selected, and the vehicle height rises from the reference vehicle height T to the set vehicle height T2. The vehicle height increasing process and the vehicle height returning process for returning the increased vehicle height to the reference vehicle height T are executed according to the flowcharts shown in FIGS.

In the vehicle height increasing process, when the vehicle height increasing switch 43 is turned on in step C1, it is determined in step C2 whether or not the vehicle is in the vehicle height increasing state. In this determination, it is determined whether or not the detection information of the vehicle height sensors 22 and 23 exceeds the reference vehicle height T, and if the vehicle height is equal to or lower than the reference vehicle height T, the vehicle speed is determined in step C3. If the vehicle speed information from the vehicle speed sensor 41 does not exceed the set speed V in step C3, the process proceeds to step C4. That is, even if the driver who drives the vehicle 1 with the vehicle height up switch 43 turned on has an intention to increase the vehicle height, the vehicle speed is set even if the vehicle body 2 is not in the vehicle height up state but is in a state where the vehicle height can be increased. If the speed V is exceeded, the vehicle height increasing process is not performed. that is,
When the vehicle height is increased, the pressure inside the air springs 6, 7, 8 becomes a predetermined pressure or more, and the vertical G
And the load on the air springs 6, 7, 8 increases. Therefore, the suspension is protected without performing the vehicle height increasing process. The purpose of increasing the vehicle height is to prevent the lower part of the vehicle body from being rubbed when a low-floor bus goes up a step portion between a pavement and a road or a slope.

When the condition for increasing the vehicle height of the vehicle body 2 is cleared, the air supply solenoid valve 2 used for increasing the vehicle height in step C5.
4, 25, 26 and vehicle height increasing solenoid valves 30, 31, 32
Is determined to be normal. If there is no abnormality, a buzzer sounding command is output in step C6, and if abnormal, a diagnosis lighting instruction is output in step C8 and the routine returns.
When the sounding time of the buzzer 46 elapses according to the command in step C6, as shown in FIG.
26 and the vehicle height increasing solenoid valves 30, 31, and 32 are turned on until the vehicle height reaches the set vehicle height T2 in step C7.

In FIG. 2, the supply air solenoid valves 24, 25,
26 are turned on, the first connection ports 24
a, 25a, 26a and each second connection port 24b, 25b, 2
6b are in communication with each other, and the air from the air tank 12 flows through the branch passages 33, 34, 35 to the air passage 9
B, 10B, and 11B. When the vehicle height increasing solenoid valves 30, 31, 32 are turned on, the solenoid valves 30, 31, 32 close and the air passages 9B, 10B, 1 are closed.
1B and the air passages 9A, 10A and 11A are shut off.

In such a state, the leveling valves 16, 17, 18 are provided with the supply air solenoid valves 24, 25, 2.
6 and the solenoid valves for exhaust 27, 28, 29 do not supply air, and the lock state is established. Therefore, the air from the air tank 12 is directly introduced into the air springs 6, 7, 8 to raise the vehicle height from the reference vehicle height. I do.

As the vehicle height rises, the swinging levers 16b, 17b, 18b of the leveling valves 16, 17, 18
, The leveling valves 16, 17, and 18 try to exhaust, but each leveling valve 16, 1
Since the air passages to 7, 18 are shielded, the leveling valves do not function even if the vehicle height increases, and the vehicle height can be reliably increased to the predetermined vehicle height T2.

In the vehicle height return process, when the vehicle height up switch 43 is turned off in step D1 of FIG. 8, it is determined in step D2 whether or not the vehicle height is up, and if the vehicle height up switch 43 is not off. If the vehicle height is not up, the routine returns. That is, the vehicle height return condition is set to step D
1 and D2, and when these are cleared, step D
3. Exhaust solenoid valves 27, 28, 2 used for return operation in 3.
It is determined whether 9 is normal. If the result of this determination is that there is no abnormality in the exhaust solenoid valves 27, 28, 29, step D
In step 4, a buzzer sounding command is output.
At step 6, a diagnosis lighting instruction is output and the routine returns. When the sounding time of the buzzer 46 elapses in accordance with the command in step D4, as shown in FIG.
Only 9 is kept on until the vehicle height reaches the reference vehicle height T.

In FIG. 2, supply air solenoid valves 27, 28,
When each of the first connection ports 27 is turned on,
a, 28a, 29a and the third connection ports 27c, 28c, 2
9c are in communication with each other. At this time, the vehicle height increasing solenoid valves 30, 31, 32 and the air supply solenoid valves 24, 25, 2
6 is in the OFF state, the air from the air tank 12 does not flow to the branch passages 33, 34, 35 but flows to the leveling valves 16, 17, 18. For this reason, the air of the air springs 6, 7, and 8 is discharged by the exhaust solenoid valve 2
It is discharged directly from 7, 28, 29 until the reference vehicle height T is reached. When the vehicle body 2 is in the up state, the swing levers 16b, 17b, 1 of the leveling valves 16, 17, 18
Since 8b is in a lowered state, the air from the air tank 12 is exhausted into the atmosphere and is not supplied to the air springs 6, 7, and 8. Therefore, the vehicle height returning operation can be performed quickly, and the supply of air from the air tank 12 is cut off, so that the vehicle height can be reliably reduced to the reference vehicle height T.

As described above, in the vehicle height adjusting device of the present embodiment,
The exhausting electromagnetic valves 27, 28, 29 lower the vehicle body 2 from the reference vehicle height T at the time of vehicle height reduction adjustment, and the leveling valves 16, 1 are used.
The air is exhausted from the air springs 6, 7, 8 without passing through the air valves 7, 18, and the air supply solenoid valves 24, 25,
The air from the air tank 12 is supplied to the air springs 6, 7, and 8 without passing through the leveling valves 16, 17, and 18 at the time of the return adjustment in which the vehicle body 26 whose height has dropped is returned to the reference vehicle height T.

The air passages 9A, 10 between the leveling valves 16, 17, 18 and the exhaust solenoid valves 27, 28, 29
A, 11A, the air passage 9A, 10A,
Solenoid valves 30, 31, 32 for increasing the vehicle height that shield 11A
The leveling valve 1 when the vehicle height is increased.
6, 17 and 18 stop functioning and leveling valve 1
The vehicle height can be increased without increasing the length of the connecting rod, which is the movable range of the swing levers 16b, 17b, 18b of 6, 17, 18 even if the vehicle is an air suspension vehicle having a low floor type and a kneeling mechanism. The vehicle height can be made higher than the vehicle height T. As a result, the contact and rubbing between the vehicle body 2 and the stepped portion, which occur when the vehicle 1 passes through the place having the stepped portion, can be reliably prevented.

[0047]

According to the first aspect of the present invention, when the vehicle height is adjusted, the air spring is supplied to the air spring without the intervention of the leveling valve by the vehicle height information signal from the vehicle height increasing solenoid valve and the vehicle height detecting means. Since the air is supplied and exhausted, the vehicle height can be quickly raised or lowered. When the vehicle height is raised from the reference height to the set height, the passage is shut off by a vehicle height increasing solenoid valve provided in the air passage between the air spring and the leveling valve. The air can be supplied directly from the air supply solenoid valve to the air spring without being affected by the vehicle, and the vehicle height can be quickly adjusted.

According to the second aspect of the invention, when the vehicle speed is higher than the set vehicle speed, the vehicle height up mode is not performed, so that the load applied to the air spring due to the increase in speed is suppressed to reduce the load on the air spring. The suspension can be reduced and the suspension can be protected.

According to the third aspect of the present invention, the air is supplied to the air cylinder depending on the vehicle height at the time of adjusting the vehicle height, so that the leveling valve functions only when the air is supplied to the air cylinder. When the vehicle height is adjusted, the leveling valve keeps the vehicle height constant even if the vehicle height fluctuates due to load fluctuations. .

[Brief description of the drawings]

FIG. 1 is a schematic configuration plan view showing an embodiment of an air suspension vehicle according to the present invention.

FIG. 2 is a diagram showing a piping configuration of a suspension section of the air suspension vehicle according to the present invention.

FIG. 3 is a block diagram illustrating a configuration of a vehicle height adjusting device of an air suspension vehicle according to an embodiment of the present invention.

FIG. 4 is a block diagram illustrating the operation of each solenoid valve used in the vehicle height adjustment device for each vehicle state.

FIG. 5 is a flowchart showing a kneeling processing operation performed by the control means of the present invention.

FIG. 6 is a flowchart showing a kneeling return processing operation performed by the control means of the present invention.

FIG. 7 is a flowchart showing a vehicle height increasing process operation performed by the control means of the present invention.

FIG. 8 is a flowchart showing a vehicle height increase return processing operation performed by the control means of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle 2 Body 3 Chassis frame 4,5 Front and rear axle 6,7,8 Air spring 9,10,11 Air passage 9B, 10B, 11B Air passage 12 Air supply source 16,17,18 Leveling valve 21 Air syringe 27,28 , 29 Exhaust electromagnetic valve 24, 25, 26 Air supply electromagnetic valve 30, 31, 32 Vehicle height increasing electromagnetic valve 22, 23 Vehicle height detecting means 37 Control valve 38 Control means 41 Vehicle speed detecting means T Reference vehicle height V setting Vehicle speed

Claims (3)

[Claims] An air spring provided between a vehicle body and each axle disposed in front and rear of the vehicle body; an air spring provided on an air passage connecting the air spring to an air supply source; A leveling valve that is interposed between and adjusts the air supply to the air spring in accordance with the relative displacement of the distance between the vehicle body and the axle side; and An exhaust solenoid valve for exhausting air from the air spring without passing through a leveling valve, and an air supply source to the air spring without passing through the leveling valve during return adjustment of the lowered vehicle body to return to the reference vehicle height An air-suspension vehicle having an air supply solenoid valve for supplying air from a vehicle, and opening and closing the exhaust solenoid valve and the air supply solenoid valve to adjust the vehicle height of the vehicle body / return adjustment A vehicle height increasing electromagnetic valve provided in an air passage connecting the leveling valve and the exhaust electromagnetic valve for opening and closing the air passage; a vehicle height detecting means for detecting a height of the vehicle body; Vehicle height information is input from the height detecting means, and the exhaust solenoid valve, the air supply solenoid valve, and the vehicle height increasing solenoid valve are electrically connected to perform the vehicle height reduction / return adjustment. Control means for controlling the drive of the exhaust solenoid valve and the air supply solenoid valve based on signals from the vehicle height increasing solenoid valve and the vehicle height detecting means when the vehicle height of the vehicle body is adjusted. The suspension vehicle is a low-floor type vehicle in which the distance between the vehicle body and the axle side is narrow at a reference vehicle height, and the control means performs a vehicle height up mode in which the vehicle height of the vehicle body is higher than the reference vehicle height. When in this height-up mode , With shielding the air passage between the leveling valve and the discharge valve in the solenoid valve for the vehicle height up,
Until the vehicle height information of the vehicle height detecting means reaches the set vehicle height, control is performed so that air from the air supply source is supplied to the air spring without passing through the leveling valve from the air supply solenoid valve. A height adjustment device for an air suspension vehicle, characterized in that: 2. The vehicle height adjusting device according to claim 1, wherein said control means is electrically connected to a vehicle speed detecting means for detecting a vehicle speed of said vehicle body, and is detected by said vehicle speed detecting means. A vehicle height adjusting device for an air suspension vehicle, wherein the vehicle height increasing mode is performed when the vehicle speed is equal to or lower than a set vehicle speed. 3. The vehicle height adjusting device according to claim 1, wherein a rear leveling valve for controlling air supply to an air spring on the rear axle side is provided with a control valve. An air cylinder connected to a supply source is connected to the rear axle side, and the control valve is controlled by the vehicle control means based on vehicle height information from the vehicle height detection means at the time of adjusting the vehicle height from the reference vehicle height. A vehicle height adjustment device for an air suspension vehicle, wherein the vehicle height adjustment device is controlled so that the air supply source communicates with the air cylinder.