JPH04337155A - Transmission shaft - Google Patents

Abstract

PURPOSE:To simplify fabrication work by providing an through-hole in a shaft core, and fitting an partitioning member therein at its specified position hermetically, in a transmission provided with wall reduction hole for reduction of weight as well as an oil passage for flowing lublicant in a shaft. CONSTITUTION:In the axial core of a steel-made transmission shaft 5, a wall reduction hole 7b for the reduction of weight as well as an oil passage 7a for flowing lublicant are provided. In this case a through-hole 7 is bored in the axial core in the axial direction, then a disc-shaped partitioning plate 8 with a diameter almost the same as that of the through-hole 7 and a specified plate thickness and made of iron sintered alloy is inserted into the through-hole 7 to its specified position so as to partition the through-hole into the oil passage 7a and the wall reducing hole 7b. Next an oil hole 7d is radially bored in the oil passage 7c at its end 7c in order to communicate the oil passage 7a to the outside, thereby enabling lublicant to be supplied to a gear 6 and the like. Thereafter the shaft 5 is heat treated for carburizing hardening and the partition plate 8 is joined integrally.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission shaft for a vehicle.

0002

2. Description of the Related Art Conventionally, some transmission shafts for vehicles have oil passages for passing lubricating oil inside the shaft made of steel, and also have hollow holes for the sole purpose of reducing the weight of the shaft. FIG. 2 schematically shows this type of transmission shaft, in which a plurality of gears 2, 2 are integrally formed on the transmission shaft 1. Further, an oil passage 3 and a lightening hole 4 are provided inside the transmission shaft 1. The oil passage 3 is formed by drilling along the axis of the transmission shaft 1 from the left end in the drawing toward the center of the transmission shaft 1, and has a terminal end 3a that communicates the oil passage 3 with the outside. Oil holes 3b are drilled in the radial direction. On the other hand, the lightening hole 4 is formed by drilling in the axial direction from the right end of the transmission shaft 1 toward the center, and a partition wall 1a is left between the lightening hole 4 and the oil passage 3. There is.

0003

[Problems to be Solved by the Invention] By the way, the above-mentioned drilling process for the oil passage 3 and the lightening hole 4 is
In order to leave the partition wall 1a between the transmission shaft 1 and the left and right ends of the transmission shaft 1, the process is performed separately from both ends of the transmission shaft 1, resulting in twice the effort. Furthermore, since each hole has to be stopped midway, the work is troublesome, and this increases the processing cost.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a transmission shaft in which drilling for oil passages and lightening holes is simplified.

[0005]

[Means for Solving the Problems] In order to achieve the above object, according to the present invention, a through hole is provided in the axis of the transmission shaft, a partition member is fitted in a predetermined position in a fluid-tight manner, and one side is connected to an oil passage. The structure is as follows.

[0006]

[Operation] A through hole is made in the axis of the transmission shaft by a single drilling process, a partition member is fitted into a predetermined position of the through hole, and an oil passage is formed on one side of the through hole. This simplifies the machining work for the oil passage of the transmission shaft, reduces the number of steps, and reduces the machining cost.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 schematically shows a transmission shaft according to the present invention, and a plurality of gears 6, 6 are integrally formed on a transmission shaft 5 made of steel. At the shaft axis of the transmission shaft 5,
An oil passage 7a for passing lubricating oil and a hollow hole 7b for the sole purpose of reducing weight are provided. The oil passage 7a and the lightening hole 7b are provided concentrically in the axial direction of the transmission shaft 5, and the oil passage 7a is partitioned in a fluid-tight manner between the oil passage 7a and the lightening hole 7b. A partition plate 8 is provided so that the lubricating oil in the oil passage 7a flows through the hollow hole 7.
It is designed so that it does not ooze or leak into b. Note that an oil hole 7d is drilled in the radial direction at the terminal end 7c of the oil passage 7a so that the oil passage 7a communicates with the outside, and the lubricating oil in the oil passage 7a passes through the oil hole 7d. gear 6
It is designed to be supplied to

[0008] Hereinafter, a method of machining the above-mentioned oil passage 7a and cutout hole 7b will be explained. First, a through hole 7 is formed in the axial center of the transmission shaft 5 on which a plurality of gears 6, 6 are formed, and passes through the transmission shaft 5 in the axial direction. Next, a plate made of iron-based sintered alloy is formed at a predetermined position inside the through hole 7 and has a predetermined thickness (approximately 5 mm).
A partition plate 8 formed in the shape of a disc and having approximately the same diameter as the through hole 7 is inserted and arranged, and the partition plate 8 allows the inside of the through hole 7 to be connected to the oil passage 7a and the hollow hole 7b. Divide it into sections. Then, when this transmission shaft 5 is heat-treated for carburizing and quenching, the outer circumferential surface of the partition plate 8 made of iron-based sintered alloy that comes into contact with the inner circumferential surface of the hole 7 is diffusion-bonded to the wall surface of the through-hole 7. and is integrally connected to the transmission shaft 5 within this through hole 7.

The thickness of the partition plate 8 of about 5 mm is such that the partition plate 8 is not inclined in the through hole 7 when the partition plate 8 is inserted into the through hole 7. Iron-based sintered alloys are porous and lightweight. Therefore, the weight of the transmission shaft 5 can be reduced compared to the conventional one. Further, although iron-based sintered alloy is porous, when the transmission shaft 5 is heat-treated for carburizing and quenching, the iron-based sintered alloy partition plate 8
The partition plate 8 is also carburized, and the gaps existing in the partition plate 8 are closed to make it liquid-tight. Therefore, the lubricating oil in the oil passage 7a in the transmission shaft 5 passes through the partition plate 8 and
It does not seep into b.

0010

As explained above, according to the present invention, a through hole is provided in the axis of the transmission shaft, a partition member is fitted in a predetermined position in a fluid-tight manner, and one side is used as an oil passage. This simplifies the machining work for the transmission shaft oil passage, reduces the number of processes, and reduces machining costs.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view schematically showing main parts of a transmission shaft to which the present invention is applied.

FIG. 2 is a cross-sectional view schematically showing an oil passage and a lightening hole of a conventional transmission shaft.

[Explanation of symbols]

5 Transmission shaft 7 Through hole 7a Oil road 7b Thickening hole 8 Partition board

Claims (1)

[Claims] 1. A transmission shaft, characterized in that a through hole is provided in the axis of the transmission shaft, a partition member is fitted in a predetermined position in a fluid-tight manner, and one side is provided with an oil passage.