JP3797123B2 - Suspension device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a so-called self-loader vehicle in which a vehicle body is inclined rearward and downward by the extension of an outrigger provided at the front portion of the vehicle body, and the heavy machinery is loaded onto a cargo bed by self-propelled heavy machinery. The present invention relates to an air suspension mounted on a shaft, and particularly to a maintenance mechanism thereof.
[0002]
[Prior art]
In a self-loader vehicle equipped with air suspensions on the two rear axles, as shown in FIG. 3, the entire vehicle body 3 is moved rearward and downward by the extension of the outrigger (post) 2 installed behind the cab 1. The platform 5 provided at the rear end of the loading platform 4 is inclined to ground, and the heavy machinery 7 is loaded on the loading platform 4 by using the crossover plate 6 to make the heavy machinery 7 self-propelled. is doing.
In this case, in order to avoid a change in the height of the vehicle body 3 due to the internal pressure of the air suspension respectively mounted on the rear front shaft 8 and the rear rear shaft 9, each of the rear front shaft 8 and the rear rear shaft 9 has been conventionally used. The internal pressure in the air suspension is removed, and the height of the vehicle body 3 is set at the lower limit position described later.
[0003]
However, as the vehicle body 3 tilts rearward and downward, the vertical distance between the rear front shaft 8 and the vehicle body 3 becomes larger than the vertical distance between the rear rear shaft 9 and the vehicle body 3. The diaphragm 13 of the air suspension 10 starts from the state in which the upper bump stopper 12 abuts against the piston 11 of the air suspension 10 mounted on the rear front shaft 8 (the lower limit position of the height of the vehicle body 3). Is stretched upward, the inside of the diaphragm 13 becomes negative pressure, and the middle part of the diaphragm 13 is bent inward as shown by a two-dot chain line. Once bent, it is difficult to return to the original state. Therefore, there is a possibility that the diaphragm 13 is caught between the piston 11 and the bump stopper 12 by the lowering of the vehicle body 3 to return to the vehicle running posture.
[0004]
[Problems to be solved by the invention]
The present invention is intended to protect the diaphragm of the air suspension when the vehicle body is inclined rearward and downward in a self-loader vehicle in which an air suspension is mounted on the rear front shaft of the rear two shafts.
[0005]
[Means for Solving the Problems]
For this reason, the suspension device according to the present invention, in a self-loader vehicle equipped with an air suspension on the rear front shaft of the rear two shafts, applies a set air pressure in the diaphragm of the air suspension when the vehicle body is tilted rearward and downward. It is configured to load.
[0006]
Therefore, even if the air suspension of the rear front axle is extended by tilting the vehicle body rearward and downward, the set air pressure is applied to the inside of the diaphragm of the air suspension, and the inside of the diaphragm is prevented from becoming negative pressure. Therefore, it is possible to reliably suppress the diaphragm from bending inward.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
In FIG. 1, air suspensions 20 and 21 equivalent to those in FIG. 4 are installed at both ends of the rear front shaft and both ends of the rear rear shaft of the rear biaxial self-loader vehicle, respectively. 24, the electronic control device 26 controls the solenoid valve 22 to supply compressed air from the air tank 25 to the air suspensions 20 or 21, or the air suspensions 20 and 21. The inner pressure of the diaphragm is removed.
[0008]
The air tank 25 and the passages 23 and 24 are connected by a passage 27 that bypasses the solenoid valve 22, and a pressure reducing valve 28 is installed in the passage 27. A valve 29 is installed.
[0009]
Next, the operation of the above apparatus will be described with reference to the flowchart of FIG.
In the case of loading heavy machinery or the like on a self-loader vehicle on which heavy machinery or the like is not loaded, in FIG. 2 (a), first, in step S1, the solenoid valve 22 is controlled by the electronic control unit 26, the air suspension 20, In step S2, whether or not the vehicle body is lowered to the height of the lower limit position (the state where the pistons of the air suspensions 20 and 21 are in contact with the bump stopper) is removed in step S2. Is checked, and if the vehicle body has not been lowered to the lower limit position, the process returns to step S1, but if the vehicle body has been lowered to the lower limit position, the process proceeds to step S3.
[0010]
When a lever (not shown) is operated to extend the outrigger at the front of the vehicle body in step S3, each of the three-way valves 29 is operated by the electronic control device 26 that receives the lever operation signal in the next step S4, At the same time, the communication between the air suspension 20 and the passage 23 is interrupted, and at the same time, the communication between the air suspension 20 and the passage 27 is stopped, and the air suspension 20 and the passage 27 are communicated. Air reduced to a set pressure of 0.049 MPa (1/2 atm) is supplied from the air tank 25 to the air suspension 20, and the diaphragm internal pressure of the air suspension 20 is immediately held at the set pressure.
[0011]
In step S5, the outriggers extend to tilt the vehicle body rearward and downward as shown in FIG. 3 so that heavy machinery and the like can be loaded. The three-way valves 29 are appropriately returned to the old positions by the electronic control unit 26, and the passage The communication between the air suspension 20 and the passage 27 is interrupted, and at the same time, the air suspension 20 and the passage 23 are communicated. The passage 23 and the air tank 25 are interrupted by the solenoid valve 22.
[0012]
When heavy machinery or the like is loaded in step S6, after the outrigger at the front of the vehicle body is reduced, the solenoid valve 22 is opened by the electronic control unit 26, and the air suspensions 20 and 21 are filled with air from the air tank 25. The vehicle can run.
[0013]
Further, when the heavy machinery or the like is lowered from the self-loader vehicle loaded with heavy machinery or the like, the solenoid valve 22 is controlled by the electronic control device 26 in step S11 in FIG. The internal pressure of the diaphragm 21 is removed, and in step S12, an in-vehicle height sensor (not shown) checks whether or not the vehicle body has been lowered to the lower limit position, and the vehicle body has not been lowered to the lower limit position. Step S12 is repeated, but if the vehicle body is lowered to the lower limit position, the process proceeds to Step S13.
[0014]
When a lever (not shown) is operated to extend the outrigger at the front of the vehicle body in step S13, each of the three-way valves 29 is operated by the electronic control device 26 that receives the lever operation signal in the next step S14. At the same time, the communication between the air suspension 20 and the passage 23 is interrupted, and at the same time, the communication between the air suspension 20 and the passage 27 is stopped, and the air suspension 20 and the passage 27 are communicated. Air reduced to a set pressure of 0.049 MPa (1/2 atm) is supplied from the air tank 25 to the air suspension 20, and the diaphragm internal pressure of the air suspension 20 is immediately held at the set pressure.
[0015]
In step S15, the outriggers extend to tilt the vehicle body rearward and downward as shown in FIG. 3, making it easy to lower heavy machinery, etc., and the three-way valves 29 are appropriately returned to the old positions by the electronic control unit 26. The communication between the passage 23 and the passage 27 is interrupted and at the same time the air suspension 20 and the passage 23 are communicated. However, the passage 23 and the air tank 25 are shut off by the solenoid valve 22, and in the next step S16, heavy machinery and the like are connected. Be taken down.
[0016]
That is, when the vehicle body is inclined rearward and downward due to the extension of the outrigger and the heavy machinery can be loaded and unloaded, even if the diaphragm of the air suspension 20 on the rear front shaft is extended upward due to the inclination of the vehicle body, the air suspension 20 Since the inside of the diaphragm is maintained at the set air pressure and the inside of the diaphragm of the air suspension 20 does not become negative pressure, unintentional deformation of the diaphragm is surely prevented. At this time, it is possible to prevent the diaphragm from being bitten and damaged.
[0017]
In the above embodiment, when the vehicle body is tilted rearward and downward by the extension of the outrigger, a constant set air pressure is loaded in the diaphragm of the air suspension 20, but the load load on the vehicle is large or small. Needless to say, the same effects as those of the above-described embodiment can be obtained even if a positive pressure that changes as appropriate is applied to the diaphragm of the air suspension 20 as a set air pressure.
[0018]
【The invention's effect】
In the suspension device according to the present invention, even if the air suspension of the rear front shaft is extended by tilting the vehicle body rearward and downward, the inside of the diaphragm of the air suspension is prevented from becoming negative pressure. Can be reliably suppressed from bending inwardly, so that the diaphragm can be prevented from being damaged.
[Brief description of the drawings]
FIG. 1 is a main part arrangement diagram according to an embodiment of the present invention.
FIG. 2 is an operational flowchart of the embodiment.
FIG. 3 is a perspective view of a self-loader vehicle.
FIG. 4 is a longitudinal sectional view of a main part of a self-loader vehicle.
[Explanation of symbols]
20, 21 Air suspension 22 Solenoid valves 23, 24, 27 Passage 25 Air tank 26 Electronic control device 28 Pressure reducing valve 29 Three-way valve

Claims (1)

A suspension device configured to load a set air pressure into a diaphragm of the air suspension when the rear two rear shafts are equipped with an air suspension on a rear front shaft when the vehicle body is tilted rearward and downward.

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