JP2011149519A - Shaft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently produce a shaft with a connection part of either one of a first shaft and a second shaft having a DLC (Diamond Like Carbon) coating. <P>SOLUTION: Mounting grooves 34 are provided on the outer peripheral face of the connection part 32 of the second shaft 30 and torque transmission members 36 are press-fitted and integrally fixed in the mounting grooves 34 so that portions protruding from the mounting grooves 34 function as spline teeth and are meshed with spline grooves 16 of the first shaft 12 and torque is transmitted between the first shaft 12 and the second shaft 30 via the torque transmission members 36. In that case, the torque transmission members 36 are applied with the DLC coating for the purpose of countermeasure against noise, improvement of wear resistance, etc. Since the torque transmission members 36 are small as compared with the first shaft 12 and the second shaft 30, many torque transmission members 36 can be placed in a DLC furnace at the same time and be subjected to coating treatment efficiently, so that the productivity is improved and the manufacturing cost is reduced. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a shaft in which a first shaft and a second shaft are connected so as to be slidable in the axial direction and capable of transmitting torque around an axis, and more particularly to an improvement in a shaft whose connecting portion is DLC coated. It is.

  A shaft in which a first shaft and a second shaft are connected so as to be slidable in the axial direction and capable of transmitting torque around an axis is used as a propeller shaft of a vehicle. The shaft described in Patent Document 1 is an example, and spline grooves and spline teeth that mesh with each other are provided on the inner peripheral surface of the first shaft and the outer peripheral surface of the second shaft, and are spline-fitted so as not to be relatively rotatable. In Patent Document 1, for the purpose of noise reduction and wear resistance improvement, at least one connecting portion of the first shaft and the second shaft, that is, a spline fitting portion, is DLC (Diamond Like Carbon). A coating is applied.

  The propeller shaft 10 in FIG. 3 is an example of a conventional shaft that is DLC coated on one side as described above. The first shaft 12 and the second shaft 20 are arranged concentrically and slide in the axial direction. The spline is fitted around the shaft center O so as to be able to transmit torque. 3A is a front view of the propeller shaft 10 viewed from a direction perpendicular to the axis O, and FIG. 3B is an enlarged front view of the connecting portion 22 provided at one end of the second shaft 20. FIG. 4C is an enlarged end view taken along the line IIIC in FIG. 2B, and is an end view showing a state of meshing with the spline groove 16 of the first shaft 12. FIG. As is apparent from these drawings, the connecting portion 14 of the first shaft 12 has a cylindrical shape, and a large number of spline grooves 16 are formed on the inner peripheral surface thereof at equal angular intervals in parallel with the axis O. Is provided. The connecting portion 22 of the second shaft 20 has a columnar shape inserted into the cylindrical connecting portion 14 of the first shaft 12, and the outer peripheral surface thereof is parallel to the axis O and the spline. A number of spline teeth 24 that are fitted into the grooves 16 are provided. Further, the outer peripheral surface of the connecting portion 22 of the second shaft 20 is subjected to DLC coating including the spline teeth 24. The shaded area (fine oblique lines) in FIG. 3 (b) is the portion where the DLC coating is applied.

JP 2007-177955 A

  However, when DLC coating is applied to the connecting part of the second shaft in this way, it is necessary to put the entire second shaft into the DLC furnace, including the part that is not DLC coated. There was a problem that the manufacturing cost was high due to the low efficiency. The same applies when DLC coating is applied to the connecting portion of the first shaft.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to enable efficient production of a shaft in which one of the first shaft and the second shaft is DLC coated. There is to do.

  In order to achieve such an object, the present invention provides a shaft in which a first shaft and a second shaft are connected so as to be slidable in an axial direction and capable of transmitting torque around an axis thereof. Torque that is fitted in the first groove provided on the inner periphery and the second groove provided on the outer periphery of the second shaft, and that is responsible for torque transmission between the first shaft and the second shaft And (b) the torque transmission member is DLC coated.

  In such a shaft, the first groove is provided on the inner periphery of the first shaft and the second groove is provided on the outer periphery of the second shaft, and is fitted into both the first groove and the second groove. Thus, a torque transmission member is arranged, and torque transmission is performed via the torque transmission member. In that case, the torque transmission member is DLC coated for the purpose of, for example, noise suppression or wear resistance improvement. However, since it is smaller than the first shaft and the second shaft, a large number of torque transmission members are connected to the DLC at a time. It can be put into the furnace for efficient coating, improving productivity and reducing manufacturing costs.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining one Example of this invention, (a) is a front view which shows the connection part of a 2nd shaft, (b) is an end elevation which expands and shows the IB arrow part in (a), (c) FIG. 5B is an end view showing the spline groove of the first shaft in FIG. It is a figure explaining the manufacturing process of the 2nd shaft of FIG. It is a figure explaining an example of the conventional propeller shaft, (a) is the front view seen from the direction orthogonal to the axial center O, (b) is the front view which expands and shows the connection part of a 2nd shaft, (c) FIG. 3B is an enlarged end view taken along the line IIIC in FIG. 2B, and is an end view showing a meshed state with a spline groove of the first shaft.

  The present invention is preferably applied to a propeller shaft for a vehicle, but can also be applied to other power transmission shafts. For example, the torque transmission member is integrally fixed to the second groove of the second shaft by press-fitting or the like, and is fitted into the first groove of the first shaft with a predetermined play. The first groove may be integrally fixed by press fitting or the like, and may be fitted to the second groove of the second shaft with a predetermined play. You may be made to fit in the state which has a predetermined play with respect to both the 1st groove | channel and the 2nd groove | channel, without fixing to any of a 1st shaft and a 2nd shaft.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram for explaining an example in which the present invention is applied to the propeller shaft 10 of FIG. 3, wherein (a) is a front view corresponding to (b) of FIG. 3, and (b) is (a). FIG. 4C is an enlarged end view of the portion taken along the arrow IB of FIG. 3, and FIG. 4C is an end view showing the spline groove 16 of the first shaft 12 together with FIG. 3B and corresponding to FIG. The second shaft 30 shown in FIG. 1A is used instead of the second shaft 20, and only the connecting portion 32 fitted to the first shaft 12 is different. That is, the connecting portion 32 has a columnar shape inserted into the cylindrical connecting portion 14 of the first shaft 12, and a large number of equiangular intervals are arranged on the outer peripheral surface thereof in parallel with the axis O. A mounting groove 34 is provided, and a rod-shaped torque transmission member 36 is press-fitted into the mounting groove 34 and fixed integrally therewith. A portion of the torque transmission member 36 protruding from the mounting groove 34 functions in the same manner as the spline teeth 24 and has a predetermined play with respect to the spline groove 16 provided in the connecting portion 14 of the first shaft 12. The torque is transmitted between the first shaft 12 and the second shaft 30 via the torque transmission member 36.

  Both side surfaces of the torque transmission member 36, that is, side surfaces positioned on both sides in the circumferential direction in a state of being fixed to the connecting portion 32 of the second shaft 30 as shown in FIG. 1B, have an involute curve shape. ing. The mounting groove 34 into which the torque transmission member 36 is press-fitted has substantially the same cross-sectional shape as the press-fitted portion of the torque transmission member 36. Further, both side surfaces of the spline groove 16 into which the projecting portion of the torque transmission member 36 is fitted have an involute curve shape so as to be in surface contact with the torque transmission member 36. The spline groove 16 corresponds to a first groove, and the attachment groove 34 corresponds to a second groove.

  The torque transmission member 36 is DLC coated for the purpose of noise countermeasures and wear resistance improvement. The range (a) to (c) in FIG. 1 with shadows (fine diagonal lines) is the portion where the DLC coating is applied. FIG. 2 is a view for explaining the procedure for press-fitting and fixing such a torque transmission member 36 in the mounting groove 34 of the second shaft 30. First, as shown in FIG. The required number of torque transmission members 36 are prepared, and then the DLC coating is applied to the torque transmission member 36 as shown in FIG. On the other hand, in the second shaft 30 to which the torque transmission member 36 is attached, the attachment groove 34 is formed on the outer peripheral surface of the connecting portion 32 by cutting or the like. And as shown in (d), the torque transmission member 36 is press-fitted and fixed integrally to the large number of mounting grooves 34 provided on the outer peripheral surface of the connecting portion 32. Thereby, the 2nd shaft 30 shown in FIG. 1 is obtained. In this embodiment, DLC is coated on the entire circumference of the torque transmission member 36, but the portion to be press-fitted into the mounting groove 34 is not necessarily DLC coated.

  As described above, in this embodiment, the mounting groove 34 is provided on the outer peripheral surface of the coupling portion 32 of the second shaft 30, and the torque transmission member 36 is press-fitted into the mounting groove 34 to be integrally fixed. The portion protruding from the mounting groove 34 functions as a spline tooth and meshes with the spline groove 16 of the first shaft 12, so that the first shaft 12 and the second shaft 30 are interposed via the torque transmission member 36. Torque is transmitted. In this case, the torque transmission member 36 is DLC-coated for the purpose of noise suppression and wear resistance improvement, but is smaller than the first shaft 12 and the second shaft 30, so that a large number of torque transmission members are used at one time. 36 can be put into the DLC furnace for efficient coating treatment, which improves productivity and reduces manufacturing costs.

  Further, in the present embodiment, the torque transmission member 36 is press-fitted into the mounting groove 34 of the second shaft 30 and is integrally fixed, so that there is play with respect to both the first shaft 12 and the second shaft 30. As compared with the case where the torque transmission member 36 is fitted, the rattling of the torque transmission member 36 and the generation of abnormal noise are prevented. Further, since the torque transmission member 36 is integrally fixed to the second shaft 30 and functions in the same manner as the spline teeth 24 of the conventional device, the conventional spline design module and the number of teeth can be used as they are.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this is an embodiment to the last, and this invention is implemented in the aspect which added various change and improvement based on the knowledge of those skilled in the art. Can do.

  12: First shaft 16: Spline groove (first groove) 30: Second shaft 34: Mounting groove (second groove) 36: Torque transmission member O: Shaft center

Claims (1)

In the shaft in which the first shaft and the second shaft are connected so as to be slidable in the axial direction and capable of transmitting torque around the axis,
The torque between the first shaft and the second shaft is fitted into the first groove provided on the inner periphery of the first shaft and the second groove provided on the outer periphery of the second shaft. Having a torque transmission member responsible for transmission,
The shaft, wherein the torque transmission member is DLC coated.

Images