JP2507734B2 - Propeller shaft manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a propeller shaft of an automobile or the like.

(Prior Art) For example, in an F / R type automobile, a propeller shaft is generally used as a means for connecting a transmission on the engine side and a differential device on the drive wheel side to each other to transmit a driving force. In the propeller shaft of an F / R type vehicle, the rear wheels, which are the driving wheels of the vehicle, dance in response to changes in the road surface. Therefore, the shaft itself should also dance with the front end as a fulcrum. become.

However, since the transmission side is fixed to the vehicle body, the movement of the propeller shaft needs to be optionally released in both the thrust direction and the axial direction.

Therefore, with the propeller shaft in an F / R type automobile as described above, there is usually a connecting structure that allows the spline fitting portion to freely move in the thrust direction and the universal joint portion to freely move in the axial orthogonal direction. Has been adopted.

The universal joint portion is configured to connect the transmission-side first yoke and the propeller shaft-side second yoke to each other through a cross, and the shaft portion of the first yoke is While being spline-connected to the output shaft of the transmission, the second yoke is fixedly connected to one end of the shaft member forming the propeller shaft body on the transmission side.

Conventionally, both the first and second yokes and the shaft member are formed of steel members (cast iron), and the second yoke and the shaft member are joined by welding.

However, recently, from the viewpoint of reducing the weight of the vehicle body, it has been attempted to make the yoke and the shaft member hollow and to form them both by an aluminum-based light alloy member. In that case, the yoke by welding as described above is used. If the joining method is adopted, the heat of the welding lowers the hardness of the yoke and the shaft member, which causes a problem in strength.

Therefore, in the connection between the yoke and the shaft member of the propeller shaft formed by using the above-mentioned aluminum-based light alloy member, the concavo-convex portions such as serrations or splines which are engaged with each other are formed, and the concavo-convex portions are mutually connected. Methods of connecting by conjugation are being investigated.

When the yoke and the shaft member, which is the propeller shaft main body, are coupled by the concavo-convex portions such as serrations, the concavo-convex engaging surfaces such as serrations are formed on the cylindrical yoke side shaft portion and the shaft member, respectively. There must be. Conventionally, generally, in order to form an uneven surface such as serration on the cylindrical portion as described above, for example
As shown in Japanese Laid-Open Patent Publication No. 21444, while a die having tooth forming dies corresponding to the upper and lower surfaces is set in a press device, the outer peripheral portion of the die is pressed from the outer peripheral side by a cam action during pressing. A press working apparatus is used which is provided with a cam slider for pinching along the die of the die.

(Problems to be Solved by the Invention) However, when it is attempted to manufacture the above-described automobile propeller shaft by the press working apparatus as described above, for example, after the serrations are separately formed on the yoke side and the shaft side, the However, there is a problem in that the manufacturing efficiency of the propeller shaft is high and the manufacturing cost is high.

(Means for Solving Problems) The present invention has been made for the purpose of solving the above problems, and is a combination of a cylindrical shaft member forming a propeller shaft main body and an uneven portion formed on the outer periphery. And a joint yoke having a tubular portion for use in fitting, and by fitting the tubular portion for joining of the joint yoke into the one end opening portion of the shaft member, the shaft member and the joint yoke are joined together. In the method of manufacturing a propeller shaft, the one end opening of the shaft member is fitted into a molding hole formed with a convex / concave portion that can be fitted corresponding to the concave / convex portion of the coupling tubular portion of the joint yoke. While holding it, the coupling tubular portion of the joint yoke is fitted into the one end opening of the shaft member, and then the coupling tubular portion is fitted into the coupling tubular portion. The connecting tubular portion is expanded outward in the radial direction by press-fitting a lid member having a diameter larger than the inner diameter of the connecting member from the upper side to the lower side. The shaft member is fitted into the uneven portion on the outer periphery of the coupling tubular portion by unevenness by a sandwiching force between the shaft member and the uneven portion on the outer periphery of the cylindrical portion to be coupled.

(Operation) According to the above means, the one end opening of the tubular shaft member to which the yoke is to be coupled is fitted into the molding hole having the convex and concave portions corresponding to the irregularities on the outer periphery of the coupling cylindrical portion of the yoke. The connecting tubular portion of the yoke is fitted into the opening of the one end of the shaft member, and a lid member having a diameter larger than the inner diameter of the tubular connecting portion of the yoke is press-fitted in the fitted state. Therefore, when the lid member is press-fitted, the connecting cylindrical wall of the yoke is expanded radially outward.

Then, due to the expanding action, the uneven portion on the outer periphery is fitted into the convex and concave portions of the molding hole with the cylindrical wall portion of the shaft member interposed therebetween.

As a result, the cylindrical wall portion of the shaft member is press-molded between the uneven portion on the outer circumference of the yoke-side coupling tubular portion and the convex and concave portions of the molding hole, and the concave-convex portion is firmly fitted on the outer circumferential surface of the yoke side engaging tubular portion. Are connected to each other.

(Embodiment) FIGS. 1 to 4 show a propeller shaft manufacturing apparatus for carrying out a method for manufacturing an automobile propeller shaft according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 indicates a manufacturing apparatus for carrying out the method for manufacturing the propeller shaft according to the present embodiment.
Is a lower mold 4 in which a shaft molding hole 3 for fitting and fixing a shaft member 2 forming a propeller shaft main body is formed in the center.
And an upper mold 5 corresponding to the lower mold 4.

The lower mold 4 is fixedly installed on a predetermined base, and the shaft molding hole 3 is provided with a spline 3a for forming serrations on the inner peripheral surface thereof. And
The shaft member 2 of the propeller shaft is fitted and held inside the spline 3a.

On the other hand, in the upper mold 5, a cylindrical backup holder 8 is slidably fitted in a cylindrical upper mold holder 7 for a press that can be lifted up, and the backup holder 8 is constantly pressed by pressing springs 9 and 9. While being supported in a state of being urged in the downward projecting direction, a rod-shaped punch member 10 corresponding to the shaft forming hole 3 of the lower die 4 is provided at the central axis portion thereof. The punch member 10 includes a cylindrical portion 12 for coupling a yoke 12 fitted in the upper end opening 2a of the shaft member 2.
The outer diameter is set so as to be inserted into the cavity 13 in a. As shown in FIGS. 3 to 5, the shaft forming hole 3 is formed on the outer periphery of the coupling cylindrical portion 12a of the yoke 12.
Splines 14 which engage with each other corresponding to splines 3a of
Are formed.

A yoke fitting recess 8a corresponding to the outer diameter of the yoke 12 is formed inside the backup holder 8.

On the other hand, reference numeral 15 is a lid member press-fitted into the cavity 13 of the yoke 12, the outer diameter of which is the yoke to be press-fitted.
It is formed to have a predetermined size larger than the inner diameter of the cavity portion 13 of 12. A taper surface 15 for press fitting is provided on the outer peripheral edge of the tip side.
a is formed.

Next, a method of manufacturing the propeller shaft in which the yoke 12 and the shaft member 2 are serrated by the propeller shaft manufacturing apparatus having the above-described configuration will be described.

That is, first, the upper mold 5 is pulled upward, and in this state, the shaft member 2 is fitted and fixed in the shaft molding hole 3 of the lower mold 4, and the upper end opening 2a of the fitted and fixed hollow shaft member 2 is The connecting cylindrical portion 12 of the yoke 12 is
Mate a. Then, the lower taper portion 15a of the lid member 15 is fitted and mounted in the upper end opening of the cavity 13 of the coupling cylindrical portion 12a of the yoke 12 (see FIG. 2a).

Next, the upper mold 5 is sequentially lowered from this state as shown in FIGS. 2 (b) to (c). By lowering the upper mold 5, first, as shown in FIG. 2B, the upper portion (joint portion) of the yoke 12 is fitted into the yoke fitting concave portion 8a of the backup holder 8, and the backup holder 8 causes The yoke 12 is held and deformation of the yoke 12 in the next lid member press-fitting process is prevented.

After that, when the upper die 5 further descends, the punch member 10 comes into contact with the lower die 4 at the lower end of the backup holder 8 and, as shown in FIG.
The cover member 15 is pressed downward into the hollow portion 13 of the yoke 12 by being pressed downward against the biasing force of the. As a result, the connecting cylindrical portion 12a of the yoke 12 is expanded outward in the radial direction, and the expanding action causes the projection of the spline 14 on the outer peripheral surface side to interpose the cylindrical wall portion 2b of the shaft member 2 therebetween. Will be fitted into the recess of the spline 3a of the shaft molding hole 3 of the lower mold 4, and as a result, the yoke will be
The coupling tubular portion 12a of 12 and the shaft member 2 are securely serrated.

After that, when the upper die 5 is released upward, the punch member 10
Is pulled upward from the cavity 13 of the yoke 12 and the lid member
Only 15 is left in the lower part of the cavity 13 to seal the inside of the shaft member 2.

(Effects of the Invention) As described above, the method for manufacturing a propeller shaft of the present invention has the tubular shaft member forming the propeller shaft main body and the tubular portion for coupling with the uneven portion formed on the outer periphery. A method of manufacturing a propeller shaft, comprising: a joint yoke; and the shaft member and the joint yoke are coupled to each other by fitting the coupling tubular portion of the joint yoke into an opening at one end of the shaft member. In the joint member, the one end opening of the shaft member is fitted and held in a molding hole formed with a convex and concave portion capable of fitting corresponding to the concave and convex portion of the coupling tubular portion of the joint yoke. The fitting cylindrical portion of the joint yoke is fitted into the opening at one end of the joint yoke, and then the inside diameter of the joining cylindrical portion is larger than the inner diameter of the joining cylindrical portion. By pressing the lid member downward from above, the connecting cylindrical portion is expanded outward in the radial direction, and the convex and concave portions of the molding hole and the uneven portion on the outer periphery of the connecting cylindrical portion at the time of the expansion are formed. It is characterized in that the shaft member is fitted into the concave and convex portion on the outer periphery of the coupling cylindrical portion by a clamping force between the concave and convex portions so as to be coupled.

That is, according to the method for manufacturing a propeller shaft of the present invention described above, the one end opening of the tubular shaft member to which the yoke is to be joined is formed to have the projections and depressions corresponding to the projections and depressions on the outer periphery of the joining tubular portion of the yoke. The connecting tubular portion of the yoke is fitted into the hole and fitted into the opening of the one end of the shaft member, and has a diameter larger than the inner diameter of the connecting tubular portion of the yoke in the fitted state. Since the lid member is press-fitted, when the lid member is press-fitted, the connecting tubular wall of the yoke is expanded outward in the radial direction.

Then, due to the expanding action, the uneven portion on the outer periphery is fitted to the uneven portion of the molding hole with the cylindrical wall portion of the shaft member interposed therebetween.

As a result, the cylindrical wall portion of the shaft member is press-molded between the concave-convex portion on the outer periphery of the yoke-side coupling tubular portion and the convex-concave portion of the molding hole, and the concave-convex portion is firmly fitted on the outer periphery of the yoke-side coupling tubular portion. Are connected to each other.

Therefore, it is not necessary to intentionally form the fitting concavo-convex portion on the shaft member side, and the concavo-convex portion on the outer circumference of the yoke-side coupling tubular portion can be utilized to facilitate the coupling in a single press-fitting step. As a result, manufacturing work is simplified, work efficiency is improved, and cost is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a propeller shaft manufacturing apparatus for carrying out a method for manufacturing an automobile propeller shaft according to an embodiment of the present invention, and FIGS. 2 (a) to 2 (c) are the same. FIG. 3 is a sectional view showing an operation process in the apparatus, FIG. 3 is a longitudinal sectional view showing a yoke structure in the above embodiment, FIG. 4 is a bottom view of the yoke structure, and FIG. 5 is a propeller shaft shown in FIG. It is sectional drawing (A-A line sectional drawing of FIG. 1) of a shaft member fitting part in a lower mold part of a manufacturing apparatus. 1 …… Propeller shaft manufacturing device 2 …… Shaft member 3 …… Molding hole 3a …… Spline 4 …… Lower mold 5 …… Upper mold 7 …… Upper mold holder 8 …… Backup holder 10 …… Punch member 12 …… Yoke 12a …… Cylinder part for coupling 13 …… Cavity part 15 …… Lid member

Claims (1)

(57) [Claims] 1. A tubular shaft member forming a propeller shaft main body, and a joint yoke having a tubular portion for coupling having an uneven portion formed on the outer periphery thereof, wherein the joint yoke is provided at one end opening of the shaft member. In the method of manufacturing a propeller shaft, wherein the shaft member and the joint yoke are coupled to each other by fitting the coupling tubular portion of the above, corresponding to the concavo-convex portion of the coupling tubular portion of the joint yoke. The one end opening of the shaft member is fitted and held in the molding hole formed with the convex and concave portions that can be fitted together, while the coupling cylindrical portion of the joint yoke is fitted into the one end opening of the shaft member. Then, a lid member having a diameter larger than the inner diameter of the coupling tubular portion is press-fitted into the coupling tubular portion from above to lower the coupling tubular portion in half. The shaft is expanded outward in the direction, and the shaft is formed in the uneven portion on the outer periphery of the coupling tubular portion by the sandwiching force between the convex and concave portions of the molding hole and the irregular portion on the outer periphery of the coupling cylindrical portion at the time of the expansion. A method for manufacturing a propeller shaft, characterized in that the members are fitted into and recessed from each other so as to be coupled.