JP4079325B2 - Axle housing structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a final drive device including a pinion gear, a ring gear, and a differential, and a structure of an axle housing that houses a rear axle shaft that is driven by the final drive device.
[0002]
[Prior art]
FIG. 3 is an exploded structural view around an axle housing as an example to which the present invention is applied.
The final drive device 2 is configured to be attached to the opening 15 via the gasket 6 with a bolt 16, and the concave notch that allows the large-diameter ring gear 4 to pass through the opening 15 when the final drive device 2 is assembled. Part 12 is formed.
[0003]
FIG. 5 shows the vicinity of the concave notch 12 and FIG. 6 shows the CC cross section. The outer periphery of the annular ring body 11 is fixed to the flange 10a of the axle housing 10 by a bead B1. The ring body 11 fixes the final drive 2 with bolts 16. Reference numeral 20 denotes a screw hole to which the bolt 16 is attached.
[0004]
In such a concave notch 12, the height dimension h is limited due to structural restrictions such as reducing the height dimension of the axle housing 10 and increasing the ground height as much as possible. Leakage is likely to occur.
[0005]
FIG. 7 shows the mechanism of oil leakage. When the rear axle as the unsprung part vibrates up and down and the action of separating the final drive device 2 and the axle housing 10 occurs as shown by the dotted line, Gaps such as A1 and A2 are generated. Then, the oil that has entered the gap A2 exudes outside beyond a gasket (not shown).
[0006]
There is an example in which the ring 11 is welded by an axle housing by welding assembly (see, for example, Patent Document 1).
However, in this method, no consideration is given to the concave notch.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-321539 (see FIG. 1 and its description)
[0008]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above-described problems of the prior art, and it is an object of the present invention to provide an axle housing structure in which oil leakage does not occur from a ring gear passage concave notch in an opening for mounting a final drive device. Yes.
[0009]
[Means for Solving the Problems]
As a result of various studies on the oil leakage from the opening of the axle housing, the present inventor has identified the cause of the oil leakage from the concave notch that occurs even within the elastic deformation, took countermeasures, and confirmed the effect by experiments.
[0010]
According to the present invention, an opening 15 is formed in an axle housing 10 that houses a final drive device 2 including a pinion gear 3, a ring gear 4, and a differential device 5, and a rear axle shaft that is driven by the final drive device 2. The outer periphery of the annular ring body 11 is welded to the axle flange 10a, and the ring body 11 and the axle flange 10a are welded and fixed at the bottom 12b of the ring gear passage recess 12 provided in the opening 15. ing.
In carrying out the present invention, it is preferable that the groove is welded and the bead protrusions are removed to make the surface smooth.
The present invention can also be applied to a front axle housing and a rear axle housing.
[0011]
Further, according to the present invention, the side portion 12a of the ring gear passage recess 12 is also welded.
As a result, it is possible to perform reliable welding by omitting difficult welding work to the R portion that rises from the bottom.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The names and symbols used in the description of the prior art are used redundantly for devices and members having the same function and configuration.
[0013]
In FIG. 1, a first embodiment of the present invention will be described.
An opening 15 of the axle housing 10 has an annular ring body 11 welded and fixed to a flange portion 10a formed on the axle housing 10 by a weld bead B1.
[0014]
A concave notch 12 is formed at the lower end of the opening 15 by connecting a substantially vertical side portion 12a and a bottom portion 12b parallel to the opening radius with an arc R.
The ring body 11 and the flange portion 10a of the concave notch 12 are formed into a bead B2 welded with a groove, and the side portion 12a and the bottom portion 12b are welded and fixed over the entire region. The bead B2 is preferably cut or ground to the same surface as the base material.
[0015]
FIG. 2 shows a second embodiment in which only the bottom 12b of the concave notch 12 is welded and fixed with the ring body 11 and the flange 10a as a bead B2A welded with a groove. Yes.
[0016]
FIG. 4 is an experimental record confirming the effect of the concave notch 12 according to the second embodiment.
FIG. 2B shows a state in which the contact width Mm applied to the bottom 12 b of the concave notch 12 is affected by the vertical load applied to the final drive device 2 and the axle housing 10. A symbol L is a peeling portion.
In FIG. 5A, the vertical axis represents the contact width Mm of the contact pressure PMP or higher, the horizontal axis represents the vertical load multiple Gn, and the effect of welding is seen. There is little decrease in the tangent face width with respect to the curve N without, and there is a significant difference. Therefore, it was found that there is a sufficient effect on unsprung vibration during traveling.
[0017]
From the above, a sufficient effect can be obtained by welding and fixing the bottom portion 12a of the concave notch 12 of the second embodiment. However, in the first embodiment, the effect is further increased by the increase in the length of the welding and fixing. I understand.
[0018]
【The invention's effect】
The effects of the present invention are listed below.
(A) Since the ring body of the notch and the axle flange according to the structure of the present invention are welded and fixed, oil leakage due to vehicle vibration load can be prevented.
(B) It was experimentally confirmed that the welding and fixing of the ring body at the notch and the axle flange are sufficiently effective only at the bottom.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a first embodiment of the present invention.
FIG. 2 is a perspective view showing a second embodiment.
FIG. 3 is an overall exploded perspective view around an axle housing showing an application site of the present invention.
FIG. 4 is a table of experimental results confirming the effects of the present invention.
FIG. 5 is a perspective view showing a concave notch portion of a conventional axle housing.
FIG. 6 is a cross-sectional view taken along the line CC of the above.
FIG. 7 is an explanatory diagram of a mechanism in which oil leakage occurs.
[Explanation of symbols]
2... Final drive device 3... Pinion gear 4... Ring gear 5... Differential device 6 .. Gasket 10 ... Axle housing 10a. Body 12 ... concave notch 12a ... side 12b ... bottom 15 ... opening

Claims (2)

  In an axle housing (10) for housing a final drive device (2) comprising a pinion gear (3), a ring gear (4) and a differential device (5), and a rear axle shaft driven by the final drive device (2) The outer periphery of the annular ring body (11) is welded to the axle flange (10a) formed in the opening (15), and the bottom of the ring gear passage recess (12) provided in the opening (15). An axle housing characterized in that the ring body (11) and the axle flange (10a) are fixed by welding at (12b).   The axle housing according to claim 1, wherein a side portion (12 a) of the ring gear passage recess (12) is also welded.

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