JPH03262702A - Center lock type axle structure of driven wheel - Google Patents

Abstract

PURPOSE:To make it possible to detach a bolt in small space by directly fitting a drive shaft to the internal circumference of a hub and providing a joint near a king pin shaft and also forming a hole for inserting a tool thereinto on the head section of a bolt for fixing the hub to the drive shaft. CONSTITUTION:A hub 12 for fixing a wheel 14 to an axle is rotatably supported to the internal circumference of an axle housing 10 through a bearing 16. The hub 12 is formed into a hollow shape. The head section of the drive shaft 18 is fitted to the internal circumference of the hub 12 through a spline 20. In addition, a cylindrical protrusion section 30 is formed outside the hub 12 in a body, and a cylindrical adapter 34 is forced to the internal circumference of the cylindrical protrusion section 30, and the head section 36a of a bolt 36 threadedly engaging with the drive shaft 18 is also locked to the adapter 34. A screw section 42 is formed on the external circumference of the head section of the cylindrical protrusion section 30, and a center lock nut 44 is threadedly engaged with the screw section 42. In such a way the wheel 14 is fixed to the hub 12.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a center lock type axle structure in which wheels, particularly steered and driven wheels, are mounted via a center lock nut.

BACKGROUND OF THE INVENTION A conventional center lock type axle is, for example, shown in the 1986 edition of the maintenance manual for Group C cars published by March, which has the configuration shown in FIG.

FIG. 3 schematically shows the disassembled parts of FIG. 2 assembled, and as shown in FIGS.
A hub 3 is rotatably supported on the inner periphery of the hub 3 via a bearing 2.2a, and a joint 4 is connected to the vehicle inside of the hub 3 via a long sleeve bolt 5. An inner race 4a of the joint 4 A drive shaft 6 is connected to the drive shaft 6 via a serration tongue 6a.

A center lock nut 8 for fixing the wheel is screwed into a threaded portion 7 formed on the outer layer of the right end in the figure of the hub 3.

By the way, when the steered wheel is a driven wheel, it is desirable to arrange the joint 4 on the kingpin axis in order to prevent the wheel from whirling around.

Therefore, in the configuration shown in Figure 3, it is necessary to place the hinge 4 as close to the wheel as possible, that is, to the right in the figure. It becomes necessary to incorporate 4.

Therefore, by arranging the joint 4 on the kingpin shaft in this way, the diameter of the hub 3 is increased, and accordingly, the diameters of the bearings 2, 2a are inevitably increased. If the strength of the bearings 2 and 2a becomes a problem, there is a possibility that the larger diameter hub 3 and the brake rotor (not shown) will interfere with each other, making the layout extremely difficult. It is extremely difficult to use this as a driven wheel.

By the way, although it is not a center lock type axle, it has an excellent axle structure in that the joint can be placed close to the wheel side. (see page) are known.

That is, the axle shown in FIG. 4 directly passes through the drive shaft 6A via a spline on the inner periphery of the hub 3A, and prevents the hub 3A from coming off through a nut 9 screwed onto the tip of the drive shaft 6A. The structure is such that this is carried out.

In addition, in FIG. 4 above, IA is the axle housing,
2A indicates a bearing, and 4A indicates a joint.

For this reason, it is conceivable to apply the axle structure shown in FIG. 4 to the center lock type axle, which has good wheel attachment/detachability, but if these two are simply combined, the structure shown in FIG. 5 is obtained.

That is, in FIG. 5 above, the hub 3A is different from the configuration shown in FIG.
A cylindrical protrusion 113b surrounding the outer periphery of the nut 9 is protruded from the cylindrical protrusion 3b, and a threaded portion 3c for screwing the center lock nut 8 is formed on the outer periphery of the cylindrical protrusion 3b.

However, if we simply consider the center lock type axle structure suitable for driven wheels, the fifth
In the figure, between the nut 9 and the cylindrical protrusion 3b, it is necessary to provide a tool S into which a tool for attaching and detaching the nut 9 is inserted, so the cylindrical protrusion 3b necessarily has a large diameter. As a result, the diameters of the threaded portion 3c and the center lock nut 8 are significantly increased.

Therefore, when tightening the center lock nut 8, the friction increases and the tightening torque becomes extremely large, making it difficult to manage the actual axial force.

Moreover, since the center lock nut 8 is enlarged, various problems arise, such as the ease of attaching and detaching the wheel is significantly deteriorated.

SUMMARY OF THE INVENTION In view of these conventional problems, it is an object of the present invention to provide a center lock type axle structure for driven wheels that allows the shift of the drive shaft to be brought as close to the king pin axis as possible and also to downsize the center lock nut. shall be.

Means for Solving the Problems In order to achieve the above object, the present invention rotatably supports a hub on the inner periphery of an axle housing via bearing means, and a drive shaft having a joint is mounted on the inner periphery of the hub. A mounting bolt that is fitted through the torque transmission means and has a tool insertion hole in the head is screwed into the center of the tip of the drive shaft, and the hub is prevented from coming off through the mounting bolt. A cylindrical protrusion that surrounds the outer periphery of the mounting bolt is provided from the hub in the central axis direction, and a threaded portion for screwing the center lock nut is formed on the outer periphery of the cylindrical protrusion.

Effects With the above structure, in the center lock type axle structure of the driven wheel of the present invention, the drive shaft is directly fitted to the inner periphery of the hub, so that the joint can be brought closer to the kingpin axis.

Furthermore, the mounting bolt for securing the hub to the drive shaft has a tool insertion hole formed in its head, so that the mounting bolt can be installed and removed at least within the space within the head. This makes it possible to reduce the diameter of the cylindrical protrusion.

Therefore, it is possible to downsize the center lock nut that is screwed into the cylindrical protrusion.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

That is, FIG. 1 shows a center lock type axle structure of a driven wheel showing one embodiment of the present invention, and lO is an upper not shown,
The axle housing is supported vertically and swingably on the vehicle body side via a lower link, and 12 is a hub for mounting a wheel 14, and the hub 12 is attached to the inner circumference of the axle housing 10 via a bearing 16 as a bearing means. Rotatably supported.

The hub 12 is formed in a hollow shape, and the distal end of the drive shaft 18 is fitted into the inner peripheral portion of the hub 12 via a spline 20 serving as a torque transmission means.

The drive shaft 8 is provided with a joint 22 near the vehicle inner side of the hub 12 (on the left side in the figure), and the drive shaft 18 is provided with flexibility through the joint 22.

A bell 26 for attaching a brake disc 24 is fixed to the flange 12a of the hub 12 via a bolt 28, and the head of the bolt 28 is formed as a pin 28a that is engaged with the wheel 14. Torque is transmitted to the wheels 14 via.

Further, a cylindrical protrusion 30 is integrally formed on the central axis on the vehicle outer side (left side in the figure) of the hub 12, and the drive shaft 18 is disposed on the inner periphery of the cylindrical protrusion 30. A stepped portion 32 is formed whose diameter increases from the fitting portion.

The stepped portion 32 is provided on the inner periphery of the cylindrical protrusion 30.
A cylindrical adapter 34 is press-fitted into the adapter 34, and a head 36a of a mounting bolt 36 that is screwed into the center of the distal end of the drive shaft 18 is engaged with the adapter 34.

Here, a hexagonal hole 38 serving as a tool insertion hole is formed in the head 36a of the mounting bolt 36 in the shape of a central axis.

40 is a snap ring to prevent the mounting bolt 6 from coming off.

Further, a threaded portion 42 is provided on the outer periphery of the tip of the cylindrical protrusion 30.
is formed, and a center lock nut 44 is attached to the threaded portion 42.
The wheel 14 is fixed to the hub 12 by tightening the center lock nut 44.

A snap pin 46 for preventing the center lock nut 44 from coming off is attached to the tip of the cylindrical protrusion 30.

With the above configuration, in the center lock type axle structure of this embodiment, the drive shaft 18 is fitted to the hub 12 via the spline 20, so that torque can be directly transmitted from the drive shaft 18 to the hub 12. Therefore, the length of the spline 20 for transmitting the required torque can be shortened compared to the case where the spline 20 is supported at two points using conventional bearings.

Therefore, the joint 22 located inside the vehicle of the hub (2) can be located closer to the wheel 14, that is, closer to the kingpin shaft, and the wheel I4 can be positioned closer to the wheel 14 when bound or rebounding.
This can prevent the machine from being swung around.

Furthermore, since a mounting bolt 36 having a hexagonal hole 38 in the head 36ai is used to prevent the hub I2 from coming off from the drive shaft 18, a bar-shaped hexagonal wrench is used to attach and detach the mounting bolt 36. This makes it possible to perform the attachment and detachment work within the area of the head 36a.

Therefore, the space between the cylindrical protrusion 30 that accommodates the mounting bolt 36 and the mounting bolt 36 can be reduced, so that the diameter of the cylindrical protrusion 30 can be reduced.

Therefore, it is possible to reduce the diameter of the center lock nut 44 that is screwed into the threaded portion 42 of the cylindrical protrusion 30 along with the cylindrical protrusion 30, and the tightening torque when mounting the wheel 14 is reduced. Can be made smaller, wheel 14
It is possible to significantly improve the removability of the material.

Furthermore, since the diameter of the cylindrical protrusion 30 can be reduced despite the center lock nut type axle structure, it is possible to prevent the overall diameter of the hub I2 from increasing, thereby preventing the hub 12 from interfering with the brake rotor 24. can be prevented,
The layout around the axle can be easily done.

As described in detail, the center lock nut type axle structure of the driven wheel of the present invention has a structure in which the drive shaft is directly fitted to the inner circumference of the hub via the torque transmission means. The joint provided on the drive shaft can be brought closer to the kingpin shaft, and the wheel can be prevented from swinging around to improve running stability.

In addition, the hub is secured to the drive shaft via a mounting bolt, and a tool insertion hole is formed in the head of the mounting bolt, so that the mounting bolt can be installed and removed at least within the space within the head. This makes it possible to reduce the diameter of the cylindrical protrusion that surrounds the mounting bolt and protrudes from the hub, thereby achieving miniaturization of the center lock nut.

Therefore, when tightening the center lock nut, the torque can be accurately managed, and the ease of attaching and detaching the wheel can be greatly improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of the present invention, FIG. 2 is an exploded perspective view of a conventional center lock nut type axle,
Figure 3 is a schematic configuration diagram showing the assembled state of a conventional center lock nut type axle, Figure 4 is a sectional view of essential parts showing an example of an axle structure other than the conventional center lock nut type, and Figure 's5 is a FIG. 5 is a sectional view of a main part of an axle structure in which the axle shown in FIG. 4 is converted into a center lock nut type. IO...Axle housing, 12...Hub, 14
...wheel, 16...bearing (bearing means),
18... Drive shaft, 20... Spline (
torque transmission means), 22...joint, 30...
Cylindrical protrusion, 36... Mounting bolt, 36a... Head, 38... Hexagonal hole (tool insertion hole), 44... Center lock nut. Figure 3

Claims (1)

[Claims] (1) A hub is rotatably supported on the inner periphery of the axle housing via a bearing means, and a drive shaft having a joint is fitted on the inner periphery of the hub via a torque transmission means, and A mounting bolt having a tool insertion hole is screwed into the center of the tip of the drive shaft to prevent the hub from coming off through the mounting bolt, and a cylindrical protrusion surrounding the outer periphery of the mounting bolt from the hub is centered. 1. A center lock type axle structure for a driven wheel, characterized in that the threaded portion protrudes in the axial direction and is formed on the outer periphery of the cylindrical protrusion for screwing a center lock nut.