JPH0528089Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a front wheel propulsion shaft of a small four-wheel drive vehicle.
It can be used in small and lightweight leisure vehicles such as four-wheel buggies.

[Conventional technology]

BACKGROUND ART Small four-wheeled vehicles such as four-wheel buggies have traditionally been used for leisure or sports driving, and in recent years, four-wheel drive has been implemented to improve running performance on rough terrain.

In the case of four-wheel drive passenger cars, the engine and transmission are generally located near the front wheels, whereas in small four-wheel drive vehicles with high sportiness such as four-wheel buggies, The engine and other components are placed in the center of the vehicle body, and the center of mass is approximately aligned with the center of the vehicle body, achieving higher maneuverability and maneuverability.

In such small four-wheel drive vehicles, a rod-shaped propulsion shaft is generally used to transmit the driving force from the output shaft of the engine to the input shaft of the front wheel transmission mechanism, and both ends of the propulsion shaft are A connecting member such as a universal joint can be used to connect the end of the propulsion shaft to the output shaft and input shaft (see JP-A-61-25322), or the end of the propulsion shaft can be fitted to the input and output shafts. It has been attempted to form a spline with a similar shape (see Japanese Patent Application Laid-open No. 190029/1983).

[Problem that the invention attempts to solve]

By the way, when using a universal joint such as a yoke joint or a rubber joint, it is possible to transmit rotational force even if the axis is bent, and it can operate without problems even if the accuracy of the axis position on the engine side and front wheel side is not high. However, since displacement in the axial direction cannot be absorbed, it is necessary to separately install a spline, etc., and the joint itself is expensive and unavoidably large, and furthermore, there are problems in that the rotational force transmission operation is not smooth. .

On the other hand, propulsion shafts connected by splines have a simple structure and can operate extremely smoothly, but generally the spline connection can only be slightly displaced in the axial direction.
Manufacturing requires steps such as fitting one end of the propulsion shaft to the engine output shaft fixed to the vehicle body, fitting the input shaft to the other end, and then attaching the front wheel transmission mechanism to the vehicle body. There were problems in that the assembly work was complicated and it was difficult to remove the propulsion shaft for maintenance.

An object of the present invention is to provide a front wheel propulsion shaft for a small four-wheel drive vehicle that is small, lightweight, inexpensive, and has high workability and maintainability during assembly.

[Means for solving problems]

This invention provides a front wheel side connecting part that is spline-fitted with the input shaft of the front-wheel side transmission mechanism at one end of the propulsion shaft, and has an engine-side connecting part that is spline-fitted with the output shaft of the engine side located approximately in the center of the vehicle body at the other end. A connecting portion is provided, and either the spline shape on the engine side connecting portion side or the output shaft side is extended in the axial direction to connect the propulsion shaft to the engine by a distance that can release the engagement between the front wheel side connecting portion and the input shaft. The structure is configured to be movable to the side, and a biasing means is provided between the engine-side coupling portion and the output shaft to bias the propulsion shaft toward the front wheels, and The spline shape on the side opposite to the extended side is formed into a substantially circular arc shape with a slightly swollen middle part in the axial direction to form a spherical joint, thereby forming a front wheel propulsion shaft of a small four-wheel drive vehicle. It is.

[Effect]

In the present invention configured in this way, the driving force from the output shaft on the engine side is transmitted to the input shaft on the front wheel side via the propulsion shaft, and the front wheel side connecting portion and the engine side connecting portion are spline-fitted. Furthermore, by extending the spline fitting on the engine side connecting part side in the axial direction and making it a spherical joint, connecting members such as a universal joint are omitted, reducing size, weight, and cost.
It also realizes smooth transmission of driving force. In addition, the spline shape of one side of the spline fitting on the engine side connecting portion is extended in the axial direction so that the spline fitting of the connecting portion can be moved by a predetermined distance, and the spline shape of the opposite side is formed into a gentle arc shape. By making the spline fitting on the connecting part side a bendable spherical joint, the propulsion shaft can be moved toward the engine side and the spline fitting in the front wheel side connecting part can be released, and the spherical joint can be bent and the propulsion shaft can be bent. By tilting the front wheel and pulling out the propulsion shaft toward the front wheel with the front wheel coupling part released to the side, the engine coupling part can be uncoupled without removing the engine and front wheel side devices. The propulsion shaft is detachable to improve maintainability and workability during manufacturing. Further, by providing a biasing means, the propulsion shaft is normally biased toward the front wheel to maintain spline fitting of the front wheel side coupling portion. The present invention achieves the above object as described above.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 1, this embodiment is an example in which the front wheel propulsion shaft of the present invention is applied to a small four-wheel drive vehicle 1 in the form of a so-called four-wheel buggy. At the front, a pair of front wheels 12 using balloon tires are supported via a left and right independent double-width front wheel suspension 11, and at the rear, a swing arm type rear wheel suspension 13 is supported. Rear wheel 14 through
is supported.

An engine 20 including a transmission mechanism is mounted at a substantially central position of the vehicle body frame 10, and a side gear 21 is connected to the output shaft of the engine 20. On the rear side of this side gear 21 is a rear wheel propulsion shaft 2 inserted through the arm of the rear wheel suspension system 13.
2 is attached at one end, and the other end of the rear wheel propulsion shaft 12 is connected to a rear final gear 23 disposed between the left and right rear wheels 14, so that driving force from the engine 20 can be transmitted to the rear wheels 14. . Further, a conversion gear 30 for axial translation is connected to the front side of the side gear 21 via an intermediate propulsion shaft 24, and its output shaft is located approximately on the centerline of the vehicle body. It is connected to a front wheel differential 50 disposed between the front wheels 12 and can transmit driving force from the engine 20 to the front wheels 12 .

As shown in FIG. 2, the front wheel propulsion shaft 40 includes a hollow, slightly large-diameter front wheel side connecting portion 42 at one end of a rod-shaped shaft portion 41, and this front wheel side connecting portion 42 has a recess formed inside. The side spline shape 42A is fitted into the convex spline shape 51A formed on the outside of the input shaft 51 of the front wheel differential 50, and the convex spline shape 51A is inserted into the concave spline shape 42A as far as possible in the axial direction. It is inset across L ₁ . Here, the convex spline shape 51A is formed to have an arcuate cross section with a slightly bulged middle part in the axial direction, so that the front wheel side connecting part 42 and the input shaft 51 are configured as a so-called spherical joint, and the front wheel propulsion shaft 40 and the front wheel differential 50 are connected to each other so that driving force in the rotational direction can be transmitted and displacement in the axial direction can be absorbed, and bending of each other's axes can be absorbed within a certain range.

On the other hand, the front wheel propulsion shaft 40 includes an engine side connecting portion 43 which is similar to the front wheel side connecting portion 42 but is long in the axial direction at the other end of the shaft portion 41.
is a concave spline shape 43A formed inside.
The convex spline shape 31A is fitted into the convex spline shape 31A formed on the outside of the output shaft 31 of the conversion gear 30, and the convex spline shape 31A is formed to have an arcuate cross section with a slightly bulged middle part in the axial direction. It is configured as a spherical joint similar to the front wheel side connecting portion 42. Here, the engine side connecting portion 43
The concave spline shape 43A is formed over a longer distance in the axial direction than the convex spline shape 31A of the output shaft 31, and when the front wheel propulsion shaft 40 is fitted with the output shaft 31, the distance L ₂ >L It can be displaced axially by ₁ .

Further, a compression coil spring 44 is provided inside the engine side connecting portion 43 as a biasing means. This compression coil spring 44 has one end locked to the tip of the shaft part 41 fitted into the engine side coupling part 43 and the other end to the output shaft 3 of the conversion gear 30.
1, and is configured to urge the front wheel propulsion shaft 40 and the conversion gear 30 away from each other.

In this embodiment configured as described above, the front wheel propulsion shaft 40 is installed in the following procedure.

That is, as shown in FIG. 3A, the conversion gear 30 and the front wheel differential 50 are fixed to the vehicle body in advance, and the front wheel propulsion shaft 40 is slightly inclined, and the engine side connecting portion 43 is aligned with the output shaft 31. As shown in FIG. 3B, from the state in which the engine-side coupling portion 43 and the output shaft 31 are fitted, push the engine side coupling portion 43 and the output shaft 31 further toward the conversion gear 30 side against the compression coil spring 44, and move the front wheel propulsion shaft 40 by a distance L ₂ or more. is held at the limit of movement on the conversion gear 30 side. Next, as shown in FIG. 3C, align the axes of the front wheel side coupling part 42 and the input shaft 51, fit them together, and release the force holding the front wheel propulsion shaft 40, as shown in FIG. 3D. front wheel propulsion shaft 4
0 moves toward the front wheel differential 50 by a distance L ₁ due to the biasing force of the compression coil spring 44 and is held at the limit of movement on the front wheel differential 50 side. At this time, the engine side connecting portion 43 and the output shaft 31 are maintained fitted even if they move by a distance L ₁ <L ₂ .

On the other hand, when removing, the front wheel propulsion shaft 40 is moved a distance toward the engine 20 against the compression coil spring 44.
Move the front wheel side connecting part 42 and the input shaft 5 by L ₁ or more.
1, move the front wheel side connecting part 42 in an inclined state to the front wheel differential 50 side by a distance L ₂ or more, and then remove the front wheel propulsion shaft 40 by separating the engine side connecting part 43 and the output shaft 31. .

According to this embodiment, the following effects can be obtained.

That is, the output shaft 31 and the engine side connecting portion 43
and the front wheel side connecting portion 42 and the input shaft 5
Since the connecting parts with 1 are each spline-fitted, the driving force from the engine 20 side can be smoothly transmitted to the front wheel 12 side, and the front wheel propulsion shaft 40 can be made smaller, lighter, and cheaper by omitting the universal joint etc. .

In addition, since the engine side connecting portion 43 and the output shaft 31 are movable while maintaining spline fitting, the conversion gear 30 and the front wheel differential 50 are attached to the vehicle body.
The front wheel propulsion shaft 40 can be easily attached or removed while the front wheel propulsion shaft 40 is fixed, and maintainability and workability during manufacturing can be improved.

Furthermore, since the movable spline fitting is placed at the rear end of the front wheel propulsion shaft 40, that is, on the engine 20 side, and is normally held on the front wheel 12 side, the front wheel Even when a strong inertial force directed toward the side is applied, it is possible to avoid problems such as misalignment of the spline fittings at both ends of the front wheel propulsion shaft 40, resulting in uneven transmission.

In addition, since a compression coil spring 44 is provided in the engine side connecting portion 43 to bias the front wheel propulsion shaft 40 toward the front wheel differential 50 side, the front wheel propulsion shaft 40 is normally moved toward the front wheel 12 side and the spline fitting at both ends is performed. In addition, even if the vehicle is propped up with the front wheels up during maintenance work, the engine 2
Movement to the 0 side can be prevented.

Now, with the vehicle leaning against the front wheel propulsion shaft 4,
When attaching or detaching the 0, all you have to do is push down the front wheel propulsion shaft 40, and the work can be done easily because the vehicle body will not become unstable. It is only necessary to move the front wheel propulsion shaft 40 rearward, and the workability of maintenance and assembly can be further improved.

Furthermore, since the spline fitting between the engine side connection part 43 and the output shaft 31 is made into a spherical joint that can be bent to some extent, collision between the front wheel side connection part 42 and the input shaft 51 can be prevented by tilting the front wheel propulsion shaft 40 during attachment and detachment. This can be avoided, and no other joint or the like is required for inclining the front wheel propulsion shaft 40, which simplifies the structure and prevents transmission loss.

In addition to the spline fitting between the engine side connecting portion 43 and the output shaft 31, the spline fitting between the front wheel side connecting portion 42 and the input shaft 51 is also made of a spherical joint that can be bent to some extent, so that the conversion that is pre-fixed to the vehicle body is possible. Even if the positional accuracy of the gear 30 and the front wheel differential 50 deviates somewhat, the error can be absorbed and smooth and reliable transmission is possible.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but also includes the following modifications.

That is, concave spline shapes 43A and 42A are provided on the engine side connecting portion 43 and front wheel side connecting portion 42 at both ends of the front wheel propulsion shaft 40, and convex spline shapes are provided on the output shaft 31 of the conversion gear 30 and the input shaft 51 of the front wheel differential 50. Although the spline fitting is formed by providing the shapes 31A and 51A, the concave side and convex side of the spline shape may be selected as appropriate for implementation.

Further, in these spline fittings, the convex spline shapes 31A and 51A are formed into a substantially circular arc shape, and a spherical joint is used which can be bent to some extent. However, the concave spline shapes 43A and 42A may be formed into a substantially circular arc shape.

However, in consideration of flexibility, it is desirable that of the concave and convex spline shapes that are spline-fitted to each other, the spline shape on the shorter side in the axial direction is formed into a substantially arc shape.

Furthermore, in consideration of ease of processing, it is desirable to form the spline shape on the convex side into a substantially arc shape.

For these reasons, it is desirable that the convex spline shapes 31A and 51A have a substantially arc shape, as in the above embodiment.

On the other hand, it is not essential that both the spline fittings on the engine side connecting part 43 side and the front wheel side connecting part 42 side be spherical joints, and if the attachment and detachment of the propulsion shaft 40 is taken into consideration, the engine will extend at least in the axial direction. It is sufficient if the spline fitting on the side is a spherical joint.

Further, in the embodiment, the engine side connecting portion 43
Although the concave spline shape 43A on the side is extended and relatively movable when fitted with the convex spline shape 31A, the convex spline shape 31A on the output shaft 31 side may be extended.

Further, the biasing means interposed between the engine side connecting portion 43 and the output shaft 31 is not limited to the compression coil spring 44, but may also be a cylinder filled with compressible fluid, etc. You can select it as appropriate.

Furthermore, when the compression coil spring 44 is used, it is not limited to the inside of the engine-side connecting portion 43, but can be placed around the front wheel propulsion shaft 40 and formed at flanges or the like formed on the front wheel propulsion shaft 40 and the output shaft 31, respectively. The compression coil spring 44 may be placed on the output shaft 31 side.

Furthermore, the front wheel propulsion shaft 40 is not limited to the one in which the front wheel side connecting part 42 and the engine side connecting part 43, which are separate members, are connected to both ends of the shaft part 41, and it is also possible to form a spline shape directly on both ends of the shaft part 41. Often, the detailed shape, material, etc. may be changed as appropriate within the scope of realizing the present invention.

[Effect of idea]

As described above, the front wheel propulsion shaft for a small four-wheel drive vehicle of the present invention can be made small, lightweight, and inexpensive, and can improve workability and maintainability during assembly.

[Brief explanation of the drawing]

Figure 1 is a side view showing one embodiment of the present invention;
The figure is a partially cutaway top view showing essential parts of the embodiment, and FIG. 3 is a schematic diagram showing the operation of the embodiment. 1...Small four-wheel drive vehicle, 20...Engine, 3
0... Conversion gear on the engine side, 31... Output shaft,
31A, 42A, 43A, 51A... Spline shape on convex side and concave side, 40... Front wheel propulsion shaft, 4
2...Front wheel side connection part, 43...Engine side connection part, 44...Compression coil spring serving as biasing means, 5
0...Front wheel differential, which is a front wheel side transmission mechanism, 51...
input shaft.

Claims (1)

[Scope of utility model registration request] A front wheel side connecting portion is provided at one end of the propulsion shaft for spline fitting with the input shaft of the front wheel side transmission mechanism, and an engine side connecting portion is provided at the other end for spline fitting with the engine side output shaft located approximately in the center of the vehicle body. ,
By extending the spline shape on either the engine side connection part side or the output shaft side in the axial direction, the propulsion shaft can be moved toward the engine side by a distance that allows the engagement between the front wheel side connection part and the input shaft to be released. At the same time, a biasing means is provided between the engine-side coupling portion and the output shaft to bias the propulsion shaft toward the front wheels, and the extended portion on the engine-side coupling portion side or the output shaft side A front wheel propulsion shaft for a small four-wheel drive vehicle, characterized in that a spline shape on the side and the opposite side is formed into a substantially arc shape with a slightly bulged middle part in the axial direction to form a spherical joint.