JPH07257429A - Air suspension device for vehicle use cab - Google Patents

Abstract

PURPOSE:To suppress a cab from its excessive displacement at braking time or the like of a vehicle by providing a shutoff valve interposed in at least one part between the first/second air springs and an attitude control valve, means for detecting a braking condition of the vehicle. and a means for driving the shutoff valve in accordance with this braking condition detecting means. CONSTITUTION:When acceleration in a direction of deceleration is applied to a vehicle at braking time or the like, a nose drive of displacing a cab toward the front is generated, to displace an arm 40, and pressure air is supplied to an air spring 3F on the front side by a leveling valve 4F, on the other hand, to tend to discharge pressure air from an air spring 3R on the rear side by a leveling valve 4R. Here by solenoid valves 5F, 5R, since the air springs 3F, 3R are respectively interrupted from the leveling valves 4F, 4R, the air springs 3F, 3R can hold an internal pressure just before starting a brake, and excessively swiveling the can just after stopping a vehicle can be suppressed, so that worsening comfortableness can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an air suspension device for a vehicle cab.

[0002]

2. Description of the Related Art In cab-over type vehicles such as trucks, those supported via an air spring are known (for example, Japanese Utility Model Laid-Open No. 3-64880, Japanese Utility Model Publication 5).
No. 4472, No. 5-44770, No. 5-84580, No. 5-84581, and No. 5-286455.

Such an air suspension device for a vehicle cab is provided with a leveling valve for supplying / discharging pressurized air to / from an air spring according to the displacement of the cab with respect to the vehicle body in order to maintain the posture of the cab.

This leveling valve causes rocking of the cab when it is operated during tilting of the cab. Therefore, a cut valve is interposed between the leveling valve and the air spring as described in Japanese Utility Model Publication No. 5-4472. Then, this cut valve is connected to the tilt lock rod of the cab to restrict the supply and discharge of pressurized air to the air spring during the tilt operation to suppress swinging of the cab during the tilt operation,
As described in Japanese Utility Model Laid-Open No. 5-44770, a cut valve interposed between a leveling valve and an air spring is made to respond to a parking brake switch to regulate the supply and discharge of pressurized air to the air spring during a tilt operation. There are also those that suppress the swinging of the cab inside.

[0005]

However, when acceleration in the deceleration direction is applied to the vehicle body during braking or the like, the cab elastically supported by the air spring is displaced forward (nose dive), and at this time, leveling is performed. The valve operates to supply pressurized air to the air spring on the front side, while the pressurized air is discharged from the air spring on the rear side, so the cab may oscillate in the front-rear direction immediately after the vehicle stops. , Which was one of the factors that reduced the riding comfort. Further, as in the above-mentioned Japanese Utility Model Publication No. 5-4472, in which the cut valve and the tilt lock rod are mechanically connected to each other in order to suppress the swing at the time of tilt operation, the degree of freedom of design around the cab is high. May be reduced, and similarly, the above-mentioned actual flat surface 5
In the case of JP-A-44770, the cut valve must be constantly energized and driven even when the tilt is completed, which may cause an excessive load on the battery and deteriorate the maintainability in the case of maintenance for a long time. It was

Therefore, the present invention suppresses excessive displacement of the cab when the vehicle is being braked, etc., and is capable of suppressing the swing of the cab during tilting while ensuring the degree of freedom in design and maintainability. It is an object to provide a suspension device.

[0007]

According to a first aspect of the present invention, there are provided first and second air springs for supporting the front and rear of a cab, respectively, and between the first and second air springs and the pressurized air supply means, respectively. An air suspension device for a cab for a vehicle, which is interposed and includes an attitude control valve that supplies and discharges pressurized air to and from the first and second air springs according to the attitude of the cab. A shutoff valve interposed between at least one of the two air springs and the attitude control valve, means for detecting a braking state of the vehicle, and means for driving the shutoff valve in accordance with the braking state detecting means. An air suspension device for a vehicle cab.

In a second aspect based on the first aspect, the braking state detecting means comprises a brake switch.

A third aspect of the present invention is a cab which is hinged to a vehicle body and can be tilted, first and second air springs for supporting the front and rear of the cab, respectively, and the first and second aspects.
Is interposed between the air spring and the pressurized air supply means, and the first and second air springs are installed depending on the posture of the cab.
In a vehicle cab air suspension device including a posture control valve for supplying and discharging pressurized air to and from the air spring, means for detecting a tilting movement of the cab, and the first and second air springs and the posture control valve. And a shut-off valve that is interposed between the shut-off valve and the detecting means and selectively shuts off the air passage in response to the detecting means.

Further, in a fourth aspect based on the third aspect, the detecting means serially connects a cab lock switch for detecting a lock release of the cab and a tilt stopper switch for detecting a tilt-up position of the cab. Arrange.

[0011]

Therefore, according to the first aspect of the invention, at least one of the first and second air springs is cut off from the attitude control valve when the vehicle is being braked, and the cab immediately after the braking is maintained by maintaining the internal pressure immediately before the braking is started. Therefore, the influence of the attitude control valve that follows the attitude change of the cab during braking can be suppressed.

Further, in the second invention, in the first invention, the drive means is composed of a brake switch, so that the braking state of the vehicle can be reliably detected.

Further, according to the third aspect of the invention, the shutoff valve operates only during the tilting movement of the cab to shut off the first and second air springs from the attitude control valve, so that the load is moved during the tilt up or down movement. By holding the internal pressures of the first and second air springs to the values before the tilting operation without being affected by the operation of the attitude control valve, the swinging of the cab is suppressed, while the drive of the shutoff valve is stopped at the time of tilting up. This makes it possible to perform tilt-up for a long time.

In a fourth aspect based on the third aspect, the detecting means serially connects a cab lock switch for detecting the lock release of the cab and a tilt stopper switch for detecting the tilt-up position of the cab. Since it is provided, the shutoff valve can be driven only during the tilting operation of the cab, while the drive of the shutoff valve can be automatically stopped at the tilt-up position.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 3, a cab blower member 2 for supporting a cab (not shown) is hinged to a suspension link 11 arranged at a front end portion of a vehicle body 1,
It is supported so that it can be tilted (rotated) toward the front of the vehicle body 1 about the rotation fulcrums 21, 21.

Air springs 3F and 3F, which are first air springs and are arranged at a predetermined interval in the vehicle width direction, are interposed between the suspension link 11 hinged in front of the cabroller member 2 and the vehicle body 1. And elastically support the cab blower member 2 and also the cab blower member 2
The rear of the air spring 3 is arranged at a predetermined interval in the vehicle width direction.
The carburetor member 2 is elastically supported via R and 3R, and is elastically supported by the air springs 3F and 3R arranged at four front and rear points.

The tilting operation of the cabroller member 2 is performed by the expansion and contraction drive of the tilt drive mechanism 7 interposed between the cabrower member 2 and the vehicle body 1. The tilt drive mechanism 7 is composed of, for example, a hydraulic cylinder or the like, and the extension drive drives the cabroller member 2 to pivot forward about a pivot fulcrum 21 to a predetermined tilt-up position, while the tilt drive mechanism 7 is rotated. The contraction causes the cabrower member 2 to rotate from the tilt-up position to a predetermined tilt-down position.

As shown in FIG. 3, the air springs 3F and 3R elastically supporting the cabroller member 2 are provided with a pressurized air source 3 via leveling valves 4F and 4R as attitude control valves.
The leveling valves 4F and 4R supply and discharge pressurized air to and from the air springs 3F and 3R according to the displacement of the arm 40 connected to the vehicle body 1 via the rod 41, respectively. The lower member 2, that is, the cab (not shown) is held at a predetermined level.

Solenoid valves 5F and 5R as shutoff valves are integrally formed with the leveling valves 4F and 4R.
Air springs 3F and 3R are closed by closing valves F and 5R when energized.
Are shut off from the leveling valves 4F and 4R, and the solenoid valves 5F and 5R that communicate with the leveling valves 4F and 4R by opening the valves by stopping the energization detect the braking state in conjunction with a foot brake (not shown). Driven by a brake switch 6 as means, the brake switch 6 is turned on to close the solenoid valves 5F and 5R when the vehicle is braked, while the brake switch 6 is turned off to release the solenoid valve 5F when the brake is released.
5R opens.

With the above construction, the operation will be described below.

Since the brake switch 6 is off during the steady running of the vehicle, the leveling valve 4F,
4R and the air springs 3F, 3R communicate with each other, and the leveling valves 4F, 4R supply / discharge pressurized air to / from the air springs 3F, 3R in accordance with the level fluctuation of the cab (not shown), and the cab reaches a predetermined level with respect to the vehicle body 1. Retained.

On the other hand, when the vehicle is being braked, the brake switch 6 is turned on, the solenoid valves 5F and 5R are activated, and the air springs 3F and 3R are cut off from the leveling valves 4F and 4R.

When acceleration in a decelerating direction is applied to the vehicle body during braking or the like, a cab elastically supported by the air springs 3F, 3R generates a nose dive that is displaced forward, and the nose dive of the cab causes the arm 40 to move. Is displaced,
The leveling valve 4F supplies pressurized air to the front air spring 3F, while the leveling valve 4R tries to discharge the pressurized air from the rear air spring 3R.

Here, since the air springs 3F and 3R are shut off from the leveling valves 4F and 4R by the electromagnetic valves 5F and 5R, respectively, the air springs 3F and 3R can hold the internal pressure immediately before the start of braking, and the cab being braked can be maintained. The influence of the leveling valves 4F and 4R that follow the posture change of No. 1 is eliminated, and it becomes possible to suppress excessive swinging of the cab immediately after the vehicle stops, and it is possible to suppress deterioration of riding comfort. .

After the braking is completed, the brake switch 6
Is turned off and the leveling valves 4F, 4R and the air springs 3F, 3R are communicated again, and the pressurized air is supplied and discharged so that the cab (not shown) reaches a predetermined level.

The air springs 3F, 3R during braking
It is possible to reduce the swinging of the cab immediately after braking even if only one of the front and rear is shut off. For example, the solenoid valve 5R is removed from the leveling valve 4R and only the air spring 3F on the front side of the cab is solenoid valve 5F. By shutting off during braking by, the rise of the internal pressure of the air spring 3F due to the nose dive of the cab during braking can be suppressed, and the swinging of the cab immediately after braking can be suppressed.

FIG. 4 shows another embodiment, in which the solenoid valve 5F, 5R driven by the brake switch 6 in the first embodiment is a tilt stopper switch 71 as a means for detecting the tilting operation of a cab (not shown). It is driven by the cab lock switch 72 to suppress the swinging of the cab during the tilting operation, and other configurations are the same as those in the first embodiment.

In FIG. 4, solenoid valves 5F and 5R are connected in parallel to a circuit for driving a motor 75 for supplying pressure oil by driving a pump (not shown) to the tilt drive mechanism 7 shown in FIG. It is a thing.

The tilt stopper switch 71 is shown in FIG.
As shown in FIG. 3, the tilt drive mechanism 7 is turned off at the tilt-up position of the cab (not shown), that is, the maximum extension position of the tilt drive mechanism 7, to detect the tilt-up position. Is a switch. The tilt stopper switch 71 turned off at the tilt-up position is driven by tilt lock means (not shown) that locks the cab at a predetermined tilt-up position, and is turned on again when the tilt lock means is released during tilt-down. Become.

The cab lock switch 72 arranged in series with the tilt stopper switch 71 detects the unlocked state in response to the lock lever 22 for fixing the cab (not shown) to the vehicle body 1 at the tilt down position. While the lock is off, it is turned on, and when the lock is released, it is turned on.

The direction changeover switch 73 is switched according to the expansion / contraction direction of the tilt drive mechanism 7. When tilting up (when the tilt drive mechanism 7 is extended), the direction changeover switch 73 is switched to the circuit B in the figure to rotate the tilt stopper switch 71. While the relay 76 for driving the motor 75 is energized via the cab lock switch 72, at the time of tilt down (when the tilt drive mechanism 7 is contracted), the circuit is switched to the circuit A in the figure and the relay is provided only via the tilt stopper switch 71. 7
Energize 6 The direction change switch 73 is automatically switched from the circuit A to the circuit B at a predetermined tilt down position of the cab in the operation in the tilt down direction.

A start switch 74 is interposed between the direction changeover switch 76 and the relay 76.
The relay 76 is energized only while 4 is on and the motor 7
5 is driven.

The solenoid valves 5F and 5R are arranged in parallel with the relay 76 between the direction changeover switch 73 and the start switch 74.

Here, the tilt stopper switch 71,
Table 1 shows the relationship between the cab lock switch 72, the direction changeover switch 73 and the operation of the cab.

[0036]

[Table 1]

In order to tilt up the cab, the lock lever 22 is released and the direction change switch 73
Is switched to the circuit B, the solenoid valves 5F and 5R are closed by energization, and the air springs 3F and 3R are shut off from the leveling valves 4F and 4R.

When the start switch 74 is turned on, the motor 75 is driven and the tilt drive mechanism 7 is extended to start tilting up the cab (not shown).

During the tilting operation, the air springs 3F and 3R are moved by the solenoid valves 5F and 5R to the leveling valves 4F and 4R.
In order to maintain the internal pressure before the tilt-up, the air spring 3F only contracts according to the increase in the load movement of the cab due to the tilt-up, and the pressurized air from the leveling valve 4F that operates according to the contraction is blocked. Therefore, swinging of the cab can be prevented.

On the other hand, the air spring 3R at the rear of the cab only expands in accordance with the decrease in the load movement of the tilt-up, and the pressurized air which the leveling valve 4R is about to discharge can be blocked in accordance with the expansion, and the cab can be cut off. When tilting down, the cab can be supported again at a predetermined level.

When the tilt drive mechanism 7 reaches a predetermined tilt-up position, the tilt stopper switch 71 is turned off, so that the solenoid valves 5F, 5R are opened and the air spring 3 is opened.
F and 3R communicate with the leveling valves 4F and 4R, and the air springs 3F and 3R rise to a predetermined neutral position against the load of the cab.

At this tilt-up position, the solenoid valve 5F,
The power to the 5R is automatically cut off, so even if the cab is tilted up for maintenance for a long time, the load on the battery does not increase, and the electrical circuit is cut off for maintenance. Since it can be carried out, it is possible to prevent deterioration of maintainability.

On the other hand, when tilting down, the direction selector switch 73 is switched to the circuit A side, and when the not-shown cab locking means is released and the tilt stopper switch 71 is turned on, the solenoid valves 5F and 5R are driven to close again. Then, the air springs 3F, 3R are shut off.

When the start switch 74 is turned on in this state, the tilt drive mechanism 7 contracts to start tilt down of the cab, and tilt down is performed while rocking of the cab is prevented as in the above tilt up. When the predetermined tilt-down position is reached, the lock lever 22 locks, the cab lock switch 72 is turned off, and the direction changeover switch 73 is switched to the circuit A. Therefore, the solenoid valves 5F, 5R and the relay 76 are driven. Automatically ends, and the air spring 3F and leveling valves 4F, 4
The R communicates again and the level of the cab (not shown) can be adjusted.

Thus, the cab lock switch 7 which is turned on when the unlocking of the cab (not shown) is detected.
2, the tilt stopper switch 71 that is turned off at a predetermined tilt-up position of the cab, and the solenoid valve 5F are connected in series, so that the solenoid valve 5 can be operated only while the cab is tilted.
The air springs 3F and 3R can be shut off by the valve closing drive of F and 5R to suppress the swing of the cab, while the energization of the solenoid valves 5F and 5R can be automatically stopped at the tilt-up position of the cab. Even if the cab is tilted up for maintenance for a long time, the load on the battery does not increase and maintenance can be performed by disconnecting the electrical circuit. Since the means for detecting the operation of the cab is composed of an electric circuit, the degree of freedom in the design around the cab is not reduced.

In the second embodiment, the solenoid valve 5
Although the F and 5R are driven by the tilt stopper switch 71 and the cab lock switch 72, the solenoid valve 5 is not shown.
Even if R is eliminated and only the solenoid valve 5F that blocks the supply and discharge of the pressurized air to the air spring 3F that supports the front of the cab is provided, the swinging of the cab during the tilting operation can be suppressed.

[0047]

As described above, according to the first aspect of the invention, the first and second air springs for supporting the front and rear of the cab, respectively, and the space between the first and second air springs and the pressurized air supply means are provided. In the air suspension device for a vehicle cab, each of which is interposed between the first and second air springs according to the posture of the cab, and an attitude control valve for supplying and discharging pressurized air to the first and second air springs. And a shut-off valve interposed between at least one of the second air spring and the attitude control valve,
A means for detecting the braking state of the vehicle and a means for driving the shutoff valve according to the braking state detection means are provided, and when acceleration in the deceleration direction is applied to the vehicle body, the shutoff valve causes the first and second air springs to operate. Since each of them is cut off from the attitude control valve, the first and second air springs can hold the internal pressure immediately before braking, and it is possible to suppress excessive swinging immediately after stopping the vehicle, resulting in deterioration of riding comfort. Can be suppressed.

According to a second aspect of the present invention, in the first aspect of the present invention, the braking state detecting means is composed of a brake switch, and the braking state of the vehicle can be detected easily and reliably.

A third aspect of the present invention is a cab which is hinged to a vehicle body and can be tilted, first and second air springs for supporting the front and rear of the cab, respectively, and the first and second aspects.
Is interposed between the air spring and the pressurized air supply means, and the first and second air springs are installed depending on the posture of the cab.
In a vehicle cab air suspension device including a posture control valve for supplying and discharging pressurized air to and from the air spring, means for detecting a tilting movement of the cab, and the first and second air springs and the posture control valve. And a shutoff valve which is interposed between the shutoff valve and the shutoff valve which selectively shuts off the air passage in response to the detection means. The shutoff valve is driven only during the tilting movement of the cab to drive the first and second air springs. Can be shut off from the attitude control valve to prevent the cab from swinging during tilting, while at the tilt-up position of the cab it is possible to automatically stop the shut-off valve for maintenance purposes. Even if the cab is tilted up and left for a long time, the load on the battery is not increased, and the electrical circuit can be cut off to perform maintenance, thus preventing deterioration of serviceability. Can.

Therefore, since the means for detecting the operation of the cab is composed of an electric circuit, the degree of freedom in the design around the cab is not lowered.

According to a fourth aspect of the present invention, in the third aspect of the invention, the detecting means serially connects a cab lock switch for detecting the lock release of the cab and a tilt stopper switch for detecting the tilt-up position of the cab. Since the means for detecting the operation of the cab is formed of an electric circuit, the degree of freedom in designing the cab is not reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of an air suspension device showing an embodiment of the present invention.

FIG. 2 is a side view of the tilt drive mechanism.

FIG. 3 is also a block diagram of a pneumatic circuit.

FIG. 4 is a block diagram of a control circuit showing another embodiment.

[Explanation of symbols]

 3F, 3R Air spring 4F, 4R Leveling valve 5F, 5R Solenoid valve 6 Brake switch 71 Tilt stopper switch 72 Cab lock switch

Claims (4)

[Claims] 1. A first air spring and a second air spring which respectively support the front and rear of the cab, and the air spring is interposed between the first air spring and the second air spring and the pressurized air supply means, respectively.
An air suspension device for a vehicle cab, comprising: an attitude control valve that supplies and discharges pressurized air to and from the first and second air springs according to the attitude of the cab.
A shutoff valve interposed between at least one of the air spring and the attitude control valve, means for detecting a braking state of the vehicle, and means for driving the shutoff valve according to the braking state detecting means. An air suspension device for a vehicle cab, which is characterized in that 2. The air suspension device for a vehicle cab according to claim 1, wherein the braking state detecting means is constituted by a brake switch. 3. A tiltable cab hinged to a vehicle body, first and second air springs respectively supporting the front and rear of the cab, and between the first and second air springs and a pressurized air supply means. In an air suspension device for a cab for a vehicle, the tilt of the cab is provided in a vehicular cab, the posture control valve being provided for each of the first and second air springs according to the posture of the cab. An operating valve is provided between the first and second air springs and the attitude control valve, and a shut-off valve that selectively shuts off the air passage in response to the detecting means. An air suspension device for a vehicle cab. 4. The detecting means comprises a cab lock switch for detecting a lock release of the cab and a tilt stopper switch for detecting a tilt-up position of the cab, which are arranged in series. Cab air suspension device for vehicles.