JP4512289B2 - Vehicle with axle lift mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle having a plurality of rear wheels composed of driving wheels and driven wheels, and more particularly to a vehicle with an axle lift mechanism that can ensure a sufficient driving force when empty and lightly loaded. The present invention relates to a vehicle with an axle lift mechanism that can ensure a minimum ground height.
[0002]
[Prior art]
In a large vehicle such as a truck, as shown in FIG. 5, a plurality (two in the figure) including a drive wheel 50 disposed in front of the vehicle 53 and a driven wheel 51 disposed at an interval behind the drive wheel 50. A type having rear wheels 52 is known.
[0003]
By the way, in such a large vehicle, in order to ensure a sufficient driving force at the time of empty loading and light loading, an empty vehicle start driving auxiliary device as disclosed in JP-A-8-156562 has been proposed. . In this device, the driven shaft 51 is lifted when there is no load, and the driving force is ensured by forcibly increasing the axial weight of the driving shaft 50.
[0004]
However, if the driven wheel 51 disposed on the rear side of the vehicle is completely lifted from the ground, as shown in FIG. 5, the rear overhang L (from the center of the wheel located at the rearmost among the grounded wheels). The distance to the rear end of the vehicle changes to L ′ and exceeds the reference, and the departure angle θ (the tangent plane of the wheel located at the rearmost of the grounded wheels and the rear end of the vehicle) The angle between the line connecting the two and the longitudinal axis of the vehicle changes to θ ′, and the running performance is degraded. For this reason, the driven wheel 51 cannot be lifted completely, and the driven wheel 51 is lifted to such an extent that it is not completely lifted, and the axial load distribution between the drive shaft 50 and the driven shaft 51 is changed to ensure the driving force. It was.
[0005]
However, traveling without completely lifting the driven wheel 51 not only reduces the driving force improvement effect, but also causes the wearer wheel 51 to wear because the driven wheel 51 with a low ground pressure slides sideways when the vehicle turns. This has led to intensification of fuel consumption and deterioration of fuel consumption, leading to an increase in costs during vehicle operation.
[0006]
Accordingly, the present inventors have devised a vehicle with a lift mechanism as shown in FIGS. 6 to 8 in order to solve this problem.
[0007]
As shown in the figure, the vehicle with a lift mechanism has a drive wheel 10 and a drive shaft 13 that supports the drive wheel 10 arranged at the rearmost part of the vehicle, and the driven wheel 11 and the driven shaft 15 that supports the driven wheel 11 In addition to being arranged on the front F side, the driven shaft 15 is provided with a lift mechanism 23 for lifting the driven shaft 15 and floating the driven wheel 11 from the ground. According to this, the driven wheel 11 can be completely lifted from the ground without changing the rear overhang and the departure angle, and a sufficient driving force can be secured.
[0008]
The lower part of the lift mechanism 23 is fixed on a bracket 40 provided over the side members 21 and 21 provided on both sides of the vehicle frame 20, and the upper part thereof is fixed to the driven shaft 15 via the bracket 41. Has been.
[0009]
[Problems to be solved by the invention]
However, in this vehicle with a lift mechanism, since the drive shaft 13 is disposed behind the driven shaft 15, the propeller shaft 22 that transmits the driving force from the engine to the drive wheels 10 is provided so as to intersect the driven shaft 15. ing. Therefore, the bracket 40 spanned on the side members 21 on both sides needs to pass under the propeller shaft 22 as shown in FIG.
[0010]
Further, it is necessary to secure a sufficient distance L from the propeller shaft 22 to the bracket 40 so that the propeller shaft 22 connected to the drive shaft 13 does not come into contact with the bracket 40 due to unevenness of the ground or the like. is there.
[0011]
As a result, the lower part of the bracket 40 is positioned below the lower part of the drive shaft 13 and the ground minimum height is lowered, so that there is a problem that the running performance deteriorates (see h in FIG. 7).
[0012]
Accordingly, an object of the present invention is to provide a vehicle with an axle lift mechanism that solves the above-described problems, can secure a minimum ground height, and can secure a sufficient driving force when empty and lightly loaded.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a propeller shaft provided between side members of a vehicle frame for transmitting a driving force from an engine to a drive shaft, intersecting with the propeller shaft, and interfering with the propeller shaft. A vehicle with an axle lift mechanism that has a driven shaft that supports the driven wheel and that has a driven shaft that lifts the driven shaft, and is attached to the curved portion of the driven shaft that avoids the propeller shaft a first bracket that is, a second bracket having a mounting table located below the first bracket with attached to the cross member of the vehicle frame, is provided between the mounting table of the first bracket and the second bracket And a lift mechanism that raises and lowers the driven shaft by adjusting the distance between the first bracket and the mounting table .
[0014]
According to this, since the bracket that supports the lift mechanism is not located below the propeller shaft and the driven shaft, the height of the bracket can be increased, and the ground minimum height can be sufficiently secured. Therefore, running performance is not deteriorated.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0016]
FIG. 1 is a perspective view showing a lift mechanism of a vehicle with an axle lift mechanism according to an embodiment of the present invention, FIG. 2 is a side view showing a state in which a driven wheel and a drive wheel are grounded, and FIG. 3 is a driven wheel. FIG. 4 is a side view showing a state in which only the driving wheel is grounded by lifting it from the ground, and FIG. 4 is a front view of the driven shaft and the lift mechanism.
[0017]
The vehicle with a lift mechanism according to this embodiment has the same basic configuration as that shown in FIG.
[0018]
That is, it has a plurality of (two in the illustrated embodiment) rear wheels 12 composed of driving wheels 10 and driven wheels 11 arranged at intervals in the longitudinal direction of the vehicle. Is provided at the rearmost portion of the vehicle, and the driven wheel 11 and the driven shaft 15 that supports the driven wheel 11 are arranged on the front F side.
[0019]
An air suspension 19 is provided on the drive shaft 13 and the driven shaft 15. The air suspension 19 is connected to the lower side of the drive shaft 13 and the driven shaft 15 and includes an arm 16 extending in the longitudinal direction of the vehicle and air springs 17 provided at both ends of the arm 16. The lower part of the air spring 17 is fixed to the upper surface of the arm 16, and the upper part is attached to the side member 21 of the vehicle frame 20, so that the impact of the drive shaft 13 and the driven shaft 15 can be absorbed and reduced.
[0020]
Further, a propeller shaft 22 for transmitting a driving force from an engine mounted on the vehicle front F side to the driving wheel 10 is disposed so as to intersect the driven shaft 15. The driven shaft 15 has a shape in which the central portion is curved upward so as not to interfere with the propeller shaft 22.
[0021]
The driven shaft 15 has a lift mechanism 23 formed of an air spring for completely lifting the driven wheel 11 from the ground and grounding only the driving wheel 10 in order to secure a driving force when the loaded weight is equal to or less than a predetermined weight. Is provided.
[0022]
When the loaded weight is equal to or greater than the predetermined weight, as shown in FIG. 2, the driven shaft 15 is lowered and the vehicle travels in a state where both the driving wheel 10 and the driven wheel 11 are grounded. When the loaded weight becomes equal to or less than the predetermined weight, as shown in FIG. 3, the air is supplied to the air spring 23 and the driven shaft 15 is lifted upward to completely lift the driven wheel 11 from the ground. Only drive with grounding. According to this configuration, even if the driven wheel 11 is completely lifted from the ground, the driving force can be secured without changing the rear overhang and the departure angle.
[0023]
The gist of the present invention is that the bracket for fixing the lift mechanism 23 to the vehicle frame 20 and the driven shaft 15 is improved.
[0024]
That is, the first bracket 25 for fixing the upper part of the lift mechanism 23 to the driven shaft 15 is attached, while the second bracket for fixing the lower part of the lift mechanism 23 to the cross member 26 extending in the width direction of the vehicle frame 20. 27 is attached.
[0025]
The first bracket 25 is provided slightly shifted in the width direction with respect to the propeller shaft 22 and is provided toward the vehicle rear side.
[0026]
The second bracket 27 is attached to the cross member 26 at a position facing the first bracket 25, and extends while inclining downward from the cross member 26 side toward the first bracket 25 side. The second bracket 27 is provided avoiding the lower side of the propeller shafts 22 and 15.
[0027]
A mounting table 29 is formed at the tip of the second bracket 27, and the lower part of the lift mechanism 23 is fixed on the mounting table 29. Accordingly, the lift mechanism 23 is interposed between the first bracket 25 and the second bracket 27 while being cantilevered on the mounting table 29. In the present embodiment, the lift mechanism 23 is formed of an air spring, and the driven shaft 15 is moved up and down by adjusting the distance between the first bracket 25 and the second bracket 27 by supplying or discharging air to the air spring. Is done.
[0028]
As is apparent from the figure, according to the present embodiment, the second bracket 27 does not pass below the propeller shaft 22, so that the mounting base 29 of the second bracket 27 has the lift mechanism shown in FIGS. 6 to 8. It can arrange | position above the bracket 40 of a vehicle. Accordingly, the lower portion of the second bracket 27 is positioned above the lower portion of the drive shaft 13 and can sufficiently secure the minimum ground clearance (see H in FIG. 3).
[0029]
Here, even if the bracket 40 is attached to the side member 21 as in the vehicle with the lift mechanism shown in FIGS. 6 to 8, if the lift mechanism 23 is cantilevered, the bracket 40 Although it is possible to form the side member 21 so as not to pass below the propeller shaft 22, the side member 21 is long and has low torsional rigidity. Reinforcement is required, and the cost of the vehicle frame 20 is greatly increased.
[0030]
According to the present embodiment, since the cross member 26 is short and has high torsional rigidity, there is no need for reinforcement as a cantilever support.
[0031]
In the present embodiment, the second bracket 27 includes the cross member 26 disposed between the driven shaft 15 and the drive shaft 13, and the cross member 30 disposed on the front F side of the driven shaft 15 (FIGS. 2 and 3), and the lift mechanism 23 can be supported at both ends. In this case, the second bracket 27 needs to pass below the driven shaft 15. The distance between the driven shaft 15 and the second bracket 27 must be sufficiently secured so that the driven shaft 15 does not come into contact when the driven shaft 15 moves downward due to unevenness of the ground, and the minimum height on the ground is lowered. There is a fear.
[0032]
Further, the first bracket 25 attached to the driven shaft 15 is formed to extend downward, and the lower part of the lift mechanism 23 is fixed to the first bracket 25 and the second bracket attached to the cross member 26. It is possible to fix the upper part of the lift mechanism 23 to the bracket 27 and pull up the driven shaft 15 by the lift mechanism 23, but in this case, the first bracket 25 is not positioned below the propeller shaft 22. It is necessary to.
[0033]
So far, the air spring has been described as being used as the lift mechanism 23, but the present invention is not limited in this respect, and other configurations such as an air cylinder, a hydraulic cylinder, and an electric actuator may be used.
[0034]
Further, although the air suspension vehicle has been described, the present invention can also be applied to a trunnion suspension vehicle using a leaf spring.
[0035]
【The invention's effect】
In short, according to the present invention, the following excellent effects are exhibited.
1) Sufficient minimum ground height can be secured.
2) A sufficient driving force can be ensured when empty and lightly loaded.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a lift mechanism of a vehicle with an axle lift mechanism according to an embodiment of the present invention.
FIG. 2 is a side view showing a state in which a driven wheel and a drive wheel are grounded in a vehicle with an axle lift mechanism according to an embodiment of the present invention.
FIG. 3 is a side view showing a state where a driven wheel is lifted from the ground and only a driving wheel is grounded in a vehicle with an axle lift mechanism according to an embodiment of the present invention.
FIG. 4 is a front view of a driven shaft and a lift mechanism in a vehicle with an axle lift mechanism according to an embodiment of the present invention.
FIG. 5 is a schematic side view of a large vehicle.
FIG. 6 is a perspective view of a vehicle with a lift mechanism.
FIG. 7 is a side view of a vehicle with a lift.
FIG. 8 is a front view of a driven shaft and a lift mechanism of a vehicle with a lift.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Drive wheel 11 Drive wheel 13 Drive shaft 15 Drive shaft 20 Car frame 21 Side member 22 Propeller shaft 23 Lift mechanism 25 First bracket 26 Cross member 27 Second bracket

Claims (1)

A propeller shaft that is provided between the side members of the vehicle frame and transmits the driving force from the engine to the drive shaft, and the center portion is curved upward so as to intersect with the propeller shaft and not interfere with the propeller shaft, and a driven shaft which supports the driven wheel, a axle lift mechanism with the vehicle for lifting the driven shaft, a first bracket attached to the curved portion of the driven shaft to avoid the propeller shaft, the cross of the vehicle frame A second bracket having a mounting base mounted on the member and positioned below the first bracket; and a distance between the first bracket and the mounting base of the second bracket, and a distance between the first bracket and the mounting base A vehicle equipped with an axle lift mechanism, characterized in that a lift mechanism is provided for adjusting the height of the driven shaft to raise and lower the driven shaft.

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