JPH05193328A - Kneeling device - Google Patents

Abstract

PURPOSE:To prevent kneeling action at normal driving and carry out the kneeling action only in the case of extremely low speed or stop. CONSTITUTION:A car speed 32 is detected, and solenoid valves 17 and 23 are opened by a controller 30 only when this car speed 32 is less than a specified value so that the kneeling action is carried out by supplying a signal pressure to an exhaust valve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a kneeling device for a vehicle, and more particularly to a kneeling device for suspending wheels on a vehicle body via an air spring and exhausting air from the air spring to lower the vehicle height. ..

[0002]

2. Description of the Related Art An air spring such as an air bellows can have a spring constant lower than that of a leaf spring. Therefore, when such an air spring is used as a suspension spring, riding comfort is improved. Therefore, in large vehicles, especially buses, the wheels are suspended from the vehicle body by air springs.

The air spring can not only freely change the spring constant by adjusting the amount of air filled therein, but also can control the vehicle height by supplying and discharging the air in the air spring. You will be able to adjust. Therefore, when the air in the air spring is discharged so that the portion where the entrance / exit opening is provided is lowered at the time of getting on / off, the getting on / off property is improved.

When the bus is placed on the car ferry,
A soft air spring may cause the vehicle to wander and contact the next vehicle. Therefore, in such a case, it is preferable that the air in the air spring is discharged so that the air is completely exhausted. Therefore, in the conventional bus equipped with an air spring, a kneeling device is provided,
The air inside the air spring is exhausted if necessary.

[0005]

The above-described kneeling operation is performed by the driver operating the kneeling switch, for example, and the air in the air spring is discharged. Therefore, if such a kneeling switch is erroneously operated while the vehicle is traveling, the air spring will impair its anti-vibration effect. Alternatively, the vehicle may have an unstable posture. Furthermore, the function of adjusting the vehicle height by the leveling valve is impaired.

Therefore, for example, it is possible to perform the kneeling operation only while the vehicle is at a stop. However, in this case, the vehicle may enter a structure having a low ceiling or the height of the ceiling. The kneeling action cannot be performed when passing through a low tunnel. That is, even if the kneeling device is provided, the vehicle height cannot be lowered by the kneading device in such a case, and the interference between the ceiling of the structure or the tunnel and the upper portion of the vehicle body cannot be prevented.

The present invention has been made in view of the above problems, and the kneeling operation is not performed during normal traveling of the vehicle, and the kneeling operation is performed only at an extremely low speed or while the vehicle is stopped. It is an object of the present invention to provide a kneading device configured to do so.

[0008]

DISCLOSURE OF THE INVENTION According to the present invention, a wheel is suspended on a vehicle body via an air spring, and the air in the air spring is discharged to lower the vehicle height. A solenoid valve that controls the air spring is connected to the air spring piping system, and means for detecting the vehicle speed is provided. Is designed to be discharged.

[0009]

Therefore, only when the vehicle speed detected by the vehicle speed detecting means is below a predetermined value, for example, when the kneeling switch is operated, the solenoid valve is opened, the air in the air spring is discharged, and the kneeling operation is performed. Will be done. On the other hand, when the vehicle is traveling normally and the vehicle speed is equal to or higher than the predetermined value, the solenoid valve is not opened and the air in the air spring is not discharged even when the kneeling switch is operated.

[0010]

1 is a piping diagram of an air suspension system for a bus equipped with a kneeling system according to an embodiment of the present invention. The front wheel axle is a pair of left and right air springs 1.
Suspended by 1. On the other hand, the rear axles are suspended by two air springs 12, 13 provided on the left and right respectively. Air is supplied from the air tank 14 to these air springs 11, 12, and 13.

The air spring 11 on the front wheel side is connected to the air tank 14 via two types of air pipes 15 and 16. A solenoid valve 17 is commonly connected to the left and right sides of the air pipe 15, and the air pipe 15 is branched left and right on the downstream side of the solenoid valve 17 so as to be connected to the air spring 11 via an exhaust valve 18. It has become. On the other hand, a pair of left and right leveling valves 19 are connected to the second air pipe 16, and the leveling valve 19 is connected to the air spring 11 via the exhaust valve 18. ing.

A pair of rear left and right air springs 12, 1
3 is connected to the air tank 14 via air pipes 21 and 22. The solenoid valve 23 is connected to the air pipe 21 in common on the left and right, and the left and right air springs 1
The left and right exhaust valves 24 are connected in correspondence with Nos. 2 and 13. On the other hand, a leveling valve 25 is commonly connected to the second air pipe 22, and the leveling valve 25 is connected to the air springs 12 and 13 via the left and right exhaust valves 24.

The pressures of the front and rear air springs 11, 12, 13 are detected by low pressure switches 27, 28, respectively.
Are connected to the controller 30.

As shown in FIGS. 1 and 4, the controller 30 is further connected to a kneeling switch 31, a vehicle speed sensor 32, and an operation display lamp 33. Further, the controller 30 controls the front and rear solenoid valves 17, 23.

Next, the structure of the exhaust valves 18 and 24 connected to the solenoid valves 17 and 23 will be described. Since the front and rear exhaust valves 18 and 24 have the same structure, the structure of the front exhaust valve 18 will be described here. Exhaust valve 18
2 includes a casing 36 as shown in FIGS. 2 and 3, and the casing 36 includes an upper port 37, a side port 38, a signal port 39, and an exhaust port 40. The upper port 37 is connected to the leveling valve 19. The side port 38 is the air spring 11
It is connected to the. Further, the signal port 39 is connected to the solenoid valve 17. The exhaust port 40 is open to the atmosphere.

A plunger 43 is slidably housed in the casing 36. The plunger 43 is urged upward by a spring 44, and is abutted against the lower surface of the inlet valve 45 facing the upper port 37, thereby closing the central hole 46. When a signal pressure is applied to the chamber 47 from the electromagnetic valve 17 through the signal port 39, the plunger 43 moves downward against the coil spring 44, the upper end of the plunger 43 is separated from the inlet valve 45, and the center hole 46 is formed. Are communicated with the side port 38.

1 and 4, the solenoid valves 17 and 23 shown in FIGS. 1 and 4 are opened by a signal from the controller 30, and the exhaust valves 18 and 24 are supplied with a signal pressure. Air is discharged from the air springs 11, 12, and 13 by the valves 18 and 24, and a kneeling operation is performed.

On the other hand, when no signal is supplied from the controller 30, the solenoid valves 17 and 23 are closed and the exhaust valves 18 and 24 do not perform the exhaust operation. In such a case, the exhaust valves 18 and 24 simply function as communication passages to allow the leveling valves 19 and 25 to communicate with the air springs 11, 12, and 13. Therefore, the leveling valves 19 and 25 adjust the amount of air in the front and rear springs 11, 12 and 13 to perform the vehicle height adjustment operation. That is, usually the leveling valve 1
The vehicle height is always kept at an appropriate value by 9 and 25.

Next, the solenoid valve 1 is controlled by the controller 30.
A kneeling operation for lowering the vehicle height by opening 7, 23 will be described. When the driver operates the kneeling switch 31 connected to the controller 30, a current flows from the controller 30 to the lower terminals of the front and rear solenoid valves 17 and 23 shown in FIG. be opened. Then, the signal pressure is supplied into the chamber 47 through the signal port 39 of the exhaust valve 18 shown in FIGS. Then, the plunger 43 moves downward against the spring 44, and the state shown in FIG. 3 is obtained. Ie plunger 4
The upper end of 3 is separated from the inlet valve 45 facing the port 37,
This causes inlet valve 45 to close port 37. Then, the center hole 46 of the plunger 43 and the port 38 are communicated with each other.

When the exhaust valve 18 is thus opened by the signal pressure, the compressed air in the air spring 11 passes from the port 38 through the center hole 46 of the plunger 43 and the exhaust port 40 provided in the lower portion of the casing 36. Will be discharged through. Rear air springs 12, 1
The compressed air in 3 performs the same operation as the exhaust valve 24 on the rear side.
Exhausted through. As a result, the vehicle height is lowered and the kneeling operation is performed.

Moreover, such a kneeling operation is performed by a computer built in the controller 30.
Based on the flowchart shown in FIG. 6, the operation is performed only when the vehicle is stopped or at an extremely low speed.

The computer in the controller 30 reads the vehicle speed by the vehicle speed sensor 32, and the value is 2
Judge whether it is less than 0 km / h. Vehicle speed is 20k
If it is more than m, the kneeling operation is not performed. When the vehicle speed is 20 km or less, the output of the kneeling switch 31 is further read to determine whether or not the descending operation is being performed.
Then, in the case of the lowering operation, the solenoid valves 17, 23 are opened. On the other hand, in the case of ascending operation, the solenoid valves 17, 2
3 is closed. The raising operation is achieved by closing the exhaust valves 18, 24 and the function of the leveling valves 19, 25.

As described above, the kneeling device according to the present embodiment does not perform the kneeling operation as shown in FIG. 6 when the vehicle is normally traveling at medium speed or high speed. On the other hand, when the vehicle speed is extremely low or the vehicle is stopped, the kneeling operation is performed. Therefore, for example, when entering a structure with a low ceiling or when passing through a tunnel with a low ceiling, lower the vehicle height to prevent interference between the upper part of the vehicle body and the structure or the ceiling of the tunnel. It becomes possible to drive with.

Further, since the kneeling can be arbitrarily performed even while the vehicle is stopped, the vehicle height may be lowered in advance when the passenger gets on or off to improve the getting on / off property. If the front and rear solenoid valves 17 and 23 are controlled separately,
It is also possible to perform kneeling only for the air spring with the entrance / exit.

In the above-described embodiment, the output of the vehicle speed sensor 32 is read by the computer in the controller 30 to determine whether the vehicle speed is 20 km / h or less. You may make it use the pickup coil 50 as shown in FIG. Since the pickup coil 50 is adapted to detect the rotation speed of the wheel, the pickup coil 5
By counting the output pulses of 0, it is possible to detect whether the vehicle is stopped or whether the vehicle has a speed equal to or lower than a predetermined value.

FIG. 7 shows another embodiment. In this embodiment, the vehicle speed is estimated from the gear position of the transmission and the position of the parking lever instead of reading the vehicle speed and the rotational speed of the wheels. There is. The controller 30 includes a transmission first speed detection switch 51,
The reverse detection switch 52, the neutral detection switch 53, and a parking switch 54 for detecting that the parking lever is pulled are connected.

Therefore, when the switches 51 and 52 are ON, the controller 30 determines that the vehicle speed is extremely low. When the neutral detection switch 53 or the parking switch 54 is ON, the controller 30 detects that the vehicle is stopped. The kneeling operation is performed only in these cases.

Therefore, also in such an embodiment, it is possible to obtain the same effect as the above embodiment. The front and rear low-pressure switches 27 and 28 connected to the controller 30 are switches that are turned on when the pressure in the front and rear air pipes is, for example, 3.0 kg / cm ² or less, and monitor that the vehicle has dropped. I am trying to do it.

[0029]

As described above, the present invention is such that the air can be discharged by the solenoid valve only when the vehicle speed detected by the vehicle speed detecting means is equal to or less than a predetermined value. Therefore, the kneeling operation is performed only when the vehicle is stopped or when the vehicle speed is equal to or lower than a predetermined value, and the kneeling operation during normal traveling can be prevented. Since the kneeling operation is performed when the vehicle speed is equal to or lower than a predetermined value, when the vehicle is placed in a structure with a low ceiling or the vehicle passes through a tunnel with a low ceiling. In this case, the kneeling device can be effectively used and the vehicle height can be lowered before passing through, and it is possible to prevent interference between the upper portion of the vehicle and the structure or the ceiling of the tunnel.

[Brief description of drawings]

FIG. 1 is a block diagram of a kneading device according to a first embodiment of the present invention.

FIG. 2 is a front view of an exhaust valve of a kneeling device.

FIG. 3 is a side sectional view of the exhaust valve.

FIG. 4 is a block diagram of a control circuit of the kneeling device.

FIG. 5 is a block diagram of a control circuit according to a second embodiment.

FIG. 6 is a flowchart showing the operation of the controller.

FIG. 7 is a block diagram of a control circuit according to a third embodiment.

[Explanation of symbols]

 11 Air Spring (Front) 12, 13 Air Spring (Rear) 14 Air Tank 15, 16 Air Piping 17 Solenoid Valve (Front) 18 Exhaust Valve 19 Leveling Valve 21, 22 Air Piping 23 Solenoid Valve (Rear) 24 Exhaust Valve 25 Leveling Valve 27 Low Pressure Switch (Front) 28 Low Pressure Switch (Rear) 30 Controller 31 Kneeling Switch 32 Vehicle Speed Sensor 33 Operation Display Lamp 36 Casing 37 Upper Port 38 Side Port 39 Signal Port 40 Exhaust Port 43 Plunger 44 Spring 45 Inlet Valve 46 Center Hole 47 Chamber 50 Pickup coil 51 First speed detection switch 52 Reverse detection switch 53 Neutral detection switch 54 Parking switch

Claims (1)

[Claims] 1. A kneeling device in which a wheel is suspended from a vehicle body via an air spring, and air in the air spring is discharged to lower the vehicle height. An electromagnetic valve for controlling the discharge of air is provided in the knee device. A means for detecting the vehicle speed is provided in addition to being connected to the piping system of the spring, so that air can be discharged by the solenoid valve only when the vehicle speed detected by the means for detecting the vehicle speed is a predetermined value or less. A kneading device characterized in that