JP3625619B2 - Cab suspension device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cab suspension device in which a cab of a vehicle is suspended by a plurality of air springs provided between frames.
[0002]
[Prior art]
2. Description of the Related Art A technology for improving the riding comfort of a cab by providing a suspension device between a cab and a frame in a vehicle, particularly a large truck, is widely used, and a technology using an air spring as a spring of the suspension device is also known.
[0003]
[Problems to be solved by the invention]
However, in the above technique, the leveling valve is provided so as to keep the cab at the reference position when the cab largely moves above the reference position due to a large input from the road surface such as when the vehicle passes through a protrusion on the road surface. By this action, the air in the air bellows constituting the air spring is discharged. Therefore, air is consumed while the vehicle is running.
[0004]
In order to solve the above problem, there is an electromagnetic valve that has a structure that closes the electromagnetic valve and does not discharge air while the vehicle is running, but when the cab rises in response to input from the road surface, the air in the air bellows If it is not discharged, the effect of suppressing the cab rises is reduced. Conversely, when the cab is lowered, air is not supplied to the air bellows and the descent is not suppressed, so that there is a problem that the riding comfort deteriorates.
[0005]
Accordingly, an object of the present invention is to provide a cab suspension device that closes an electromagnetic valve only for road surface input that consumes a large amount of air and that has a low air consumption and is comfortable to ride.
[0006]
[Means for Solving the Problems]
According to the present invention, the cab (C) is provided with a plurality of air springs (1 to 4) on the front and rear sides and suspended on the frame (30), and the front and rear air springs (1 and 2, 3 and 4) are vehicle speed sensors (18) for detecting the vehicle speed in a cab suspension device connected to an air supply tank (15) via electromagnetic valves (9, 11) and leveling valves (10, 12), respectively. And a brake sensor (19) for detecting a brake signal, and stroke sensors (16, 17) for detecting the vertical strokes of the air springs (1, 4) before and after the cab (C), respectively. Connected to the vehicle speed sensor (18), the brake sensor (18), and the stroke sensor (16, 17) to connect the electromagnetic valve (9 11), a control device (20) for controlling the vehicle is provided, and the control device (20) determines a stroke range corresponding to the vehicle speed when the vehicle is running and the brake is not operating, and stroke sensors (16, 17). When the detected value does not exceed the determined stroke range, the solenoid valve (9, 11) is opened to communicate with the leveling valve (10, 12). , 11) is controlled to close.
[0008]
Further, according to the present invention, it is preferable that one stroke sensor is provided before and after the cab, or that the stroke sensor is provided near the air spring.
[0009]
According to the present invention, the cab (C) is provided with a plurality of air springs (1 to 4) on the front and rear sides and suspended on the frame (30), and the front and rear air springs (1 and 2, 3 and 4) are cab suspension devices connected to the air supply tank (15) via electromagnetic valves (9, 11) and leveling valves (10, 12), respectively, and vehicle speed sensors ( 18) and a brake sensor (19) for detecting a brake signal, and acceleration sensors (not shown) for detecting acceleration in the vertical direction are provided before and after the cab (C), respectively. (18) a control device (20) connected to the brake sensor (18) and the acceleration sensor to control the solenoid valve (9, 11) is provided; The control device (20) determines the acceleration range corresponding to the vehicle speed when the vehicle is running and the brake is not operating, and the electromagnetic valve (in the range where the detected value of the acceleration sensor does not exceed the determined acceleration range). 9, 11) is opened to communicate with the leveling valve (10, 12), and when the range is exceeded, the solenoid valve (9, 11) is controlled to be closed.
[0011]
Further, according to the present invention, it is preferable that one acceleration sensor is provided before and after the cab, or that the acceleration sensor is provided near the air spring.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0013]
In FIG. 1, vertical floor joists 31, 31 are provided on a floor (not shown) of the cab C. The front portion (left side in the drawing) of the vertical joists 31 is curved downward, and a bracket 34 is interposed at the front end portion of the frame 30. A cab C is pivotally attached to a U-shaped subframe 33 that is pivotally attached. Air bellows 1 and 2 constituting an air spring are attached between two corners of the sub-frame 33 and the tip of the frame 30, and the rear part of the vertical joist 31 is shown in detail in the cab C. It is fixed to a horizontal joist 37 provided at the lower end of the back panel.
[0014]
The rear end of the cab C is mounted on the upper surface of a cab mount bracket 36 having a horizontal joist 37 attached to the frame 30 via a bracket 35 via air bellows 3 and 4. The rear end of the cab is locked so as not to tilt by the device.
[0015]
Here, reference numeral 40 is a rearview mirror, 41 is a wiper, 42 is a speed indicator lamp, 43 is a steering wheel, 44 is a bumper, and 45 is a step. FIG. 2 is a circuit diagram showing an air circuit and an electric circuit of the cab suspension apparatus of FIG. 1, and a right air bellows 1 on the front end side (left side in the figure) of the cab C is connected to an air tank 5 and a left air bellows. 2 is connected to an air tank 6, and these air tanks 5, 6 are connected to an air supply tank 15 through an electromagnetic valve 9, a connector 13 and a protection valve 14 by an air circuit.
[0016]
The leveling valve 10 integrally formed with the electromagnetic valve 9 has a lever 10a connected to the cab C via a link (not shown). When the cab C moves upward, the air in the air bellows 1 and 2 is exhausted. When the solenoid valve is opened when the cab C moves downward and the cab C moves downward, air is supplied to the air bellows.
[0017]
Similarly, the air bellows 3 and 4 on the rear side of the cab C are also connected to the air supply tank 15 via the air tanks 7 and 8, the electromagnetic valve 11, the leveling valve 12, the connector 13, and the protection valve 14.
[0018]
Further, stroke sensors 16 and 17 are provided at the positions of the air bellows 1 and 4, and the stroke sensors 16 and 17 are connected to the control device 20 by electric circuits a and b, respectively. In addition to being connected to the electromagnetic valves 9 and 11 by d, they are connected to a vehicle speed sensor 18 for detecting a vehicle speed signal and a brake sensor 19 for detecting a brake signal.
[0019]
FIG. 3 shows the vertical strokes of the bellows 1 to 4 during travel with the vertical axis representing the air spring (air bellows) stroke and the horizontal axis representing the time. A dead zone in which the levers 10a and 12a of the valves 10 and 12 do not operate the valve, that is, a range where air is not supplied or discharged is shown. When the dead zone is exceeded, the leveling valve operates. However, in the present application, when the stroke S is exceeded, the solenoid valves 9 and 11 are closed to minimize the air consumption without impairing the riding comfort. I have control.
[0020]
The operation will be described below with reference to the control flowchart of FIG.
[0021]
In operation, it is first determined whether or not the vehicle is traveling (step S1). If NO, the process returns. If YES, it is determined whether the brake signal is ON (step S2). If YES, that is, if the brake is in operation, the solenoid valves 9 and 11 are closed (step S3), the air supply / exhaust in the air bellows is shut off, and the nose dive phenomenon of the cab C during the brake operation is alleviated.
[0022]
If NO, the vehicle speed signal is input (step S4), the vertical stroke range S of the cab C corresponding to the vehicle speed is determined (step S5), and the measurement results of the stroke sensors 16, 17 are input (step S6). ), It is determined whether or not the stroke exceeds the set range (step S7). If NO, the solenoid valves 9 and 11 are opened (step S9). If YES, the solenoid valves 9 and 11 are closed (step S8), and the control is terminated.
[0023]
Therefore, the ride comfort is not impaired while the consumption of air is minimized.
[0024]
In the above example, one stroke sensor is provided before and after the cab, but one stroke sensor may be provided near the air bellows, and one stroke sensor is attached near the center of gravity of the cab. May be.
[0025]
In addition, an acceleration sensor may be used instead of the stroke sensor. In this case, if the acceleration range for closing the solenoid valve is set appropriately, the same effect as the above example can be obtained.
[0026]
【The invention's effect】
The present invention is configured as described above, and the air bellows is controlled by opening and closing the solenoid valve with respect to the cab vertical stroke range set in accordance with the vehicle speed. The ride comfort can be prevented from being deteriorated while suppressing to a minimum, and wasteful consumption of air is suppressed even during braking.
[Brief description of the drawings]
FIG. 1 is a perspective view of a cab showing an embodiment of the present invention.
FIG. 2 is an overall view showing a configuration of an air circuit and an electric circuit of FIG.
FIG. 3 is a diagram illustrating the operation of the present invention.
FIG. 4 is a flowchart of the control of FIG.
[Explanation of symbols]
1, 2, 3, 4 ... Air bellows 5, 6, 7, 8 ... Air tank 9, 11 ... Solenoid valve 10, 12 ... Leveling valve 13 ... Connector 14 ... Protection valve DESCRIPTION OF SYMBOLS 15 ... Supply tank 16, 17 ... Stroke sensor 18 ... Vehicle speed sensor 19 ... Brake sensor 20 ... Control apparatus

Claims (2)

The cab (C) is provided with a plurality of air springs (1 to 4) on the front and rear sides and suspended on the frame (30). The front and rear air springs (1 and 2, 3 and 4) are respectively In the cab suspension device connected to the air supply tank (15) via the solenoid valves (9, 11) and the leveling valves (10, 12), a vehicle speed sensor (18) for detecting the vehicle speed and a brake signal are detected. A brake sensor (19) is provided, and stroke sensors (16, 17) for detecting the vertical stroke of the air springs (1, 4) are provided before and after the cab (C), respectively. (18) connected to the brake sensor (18) and the stroke sensor (16, 17) to control the solenoid valve (9, 11) When a control device (20) is provided and the control device (20) is traveling and not operating a brake, the stroke range corresponding to the vehicle speed is determined and the detection value of the stroke sensor (16, 17) In a range not exceeding the determined stroke range, the solenoid valve (9, 11) is opened to communicate with the leveling valve (10, 12), and when the range is exceeded, the solenoid valve (9, 11) is closed. A cab suspension device characterized by having a function of controlling in such a manner. The cab (C) is provided with a plurality of air springs (1 to 4) on the front and rear sides and suspended on the frame (30). The front and rear air springs (1 and 2, 3 and 4) are respectively In the cab suspension device connected to the air supply tank (15) via the solenoid valves (9, 11) and the leveling valves (10, 12), a vehicle speed sensor (18) for detecting the vehicle speed and a brake signal are detected. A brake sensor (19) is provided, and an acceleration sensor (not shown) for detecting vertical acceleration is provided before and after the cab (C). The vehicle speed sensor (18) and the brake sensor (18 ) And an acceleration sensor, and a control device (20) for controlling the solenoid valve (9, 11) is provided. The control device (20) When the vehicle is running and the brake is not operating, an acceleration range corresponding to the vehicle speed is determined, and the solenoid valve (9, 11) is opened if the detected value of the acceleration sensor does not exceed the determined acceleration range. A cab suspension device characterized in that it communicates with a leveling valve (10, 12) and has a function of controlling the electromagnetic valve (9, 11) to close when the range is exceeded.

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