JP2766364B2 - Manufacturing method of deformed tube - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a modified tube comprising a hollow male shaft and a female shaft which are fitted so as to slide in the axial direction.

(Prior art and its problems) This type of deformed tube is used, for example, in a joint assembly consisting of two universal joints.
Lemon-shaped ones and those having a shape similar to a spline shaft are used so that the male shaft is inside the female shaft and does not rotate around the axis with each other.

In order to manufacture these deformed tubes, a metal tube is mechanically deformed, or a male shaft and a female shaft are separately manufactured by broaching or the like, and the male shaft and the female shaft are slidably fitted. The gap was corrected manually. Therefore, not only does it take a lot of time to manufacture, but also there is a lot of play between the male shaft and the female shaft, generating noise during operation, easy to seize and seize, and the conduction efficiency of the universal joint using a deformed tube is reduced. The drawbacks are low and short service life.

Therefore, a deformed tube that can be manufactured simply and inexpensively, has no play in fitting the male shaft to the female shaft, operates without galling or seizure, and has a long service life has been desired.

(Means for Solving the Problems) In order to solve the problems, the present invention provides a method of manufacturing a deformed tube for a drive shaft, in which a male tube is fitted in a female tube so as to be slidable in an axial direction, by using a rolling die. In the above, the coating process is applied to the two metal tubes of the female and the female before rolling, and then the core metal corresponding to the inner surface of the inner male tube in a state where the two metal tubes subjected to the coating process are fitted to each other. The metal tubes fitted with each other are rolled from the outside of the female metal tube by a rolling die having a die rolling surface corresponding to the outer surface of the female tube. It is rolled into a tube.

In practicing the present invention, it is preferable to subject the inner and outer surfaces of the metal tube to a caustic treatment.

(Operation) Since a mandrel is fitted into two metal pipes fitted to each other and rolled with a rolling die at the same time, a deformed tube is manufactured.
Unlike the case where machining is performed separately, it is possible to manufacture a deformed tube without play without requiring time for adjustment after machining and with a small number of man-hours in a short time.

(Example) A case of a spline shaft-shaped male tube 2 and a female tube 4 as shown in Fig. 2 will be described as an example of a deformed tube.

The deformed tube of this embodiment is made of carbon steel pipe for machine structure. A seamless steel pipe or a seamless steel pipe may be used.

The inner and outer surfaces of the steel pipe 6 serving as the male tube 2 and the steel pipe 8 serving as the female tube 4 which are slidably fitted to each other are subjected to a caustic treatment such as a phosphate coating treatment. Alternatively, molybdenum disulfide or tungsten disulfide may be coated. The inner surface of the male tube may be omitted.

Next, a rolling die 12 having a die rolling surface 10 corresponding to the outside of the tube 4 having irregularities on the rolling surface, which is a rolling die similar to a screw rolling die for rolling a screw, is prepared. A mandrel 14 corresponding to the inner surface of the male tube 2 is prepared.

The steel pipes 6, 8 are fitted with each other and the mandrel 14 is fitted into the steel pipe 6, and the steel pipes 6, 8 (see FIG. 1) are rolled by the rolling dies 12, and are deformed as shown in FIG. Form a tube. It is preferable that the mandrel 14 and one ends of the steel pipes 6 and 8 are slightly shifted from each other so that they can be easily pulled out from each other after rolling.

In this embodiment, the case of a steel pipe has been described, but other metal pipes such as a copper pipe and an aluminum pipe may be used.

In this way, a spline-shaped deformed tube can be easily manufactured.

(Effects) According to the present invention, the mandrel 14 is fitted to the metal pipes such as the steel pipes 6 and 8 fitted to each other, and the deformed tube is rolled by the rolling die 12, so that the play is small, and therefore the power is reduced. This has the effect of easily and inexpensively manufacturing a long-life deformed tube that does not generate noise by sliding smoothly in the axial direction during transmission.

[Brief description of the drawings]

FIG. 1 shows a process for producing a deformed tube by the method of the present invention.
FIG. 2 is a view showing a state immediately before rolling with a rolling die, and FIG. 2 is a view showing a state in which a deformed tube is being rolled by the method of the present invention. 2 ... Male tube 4,4 Female tube 6,8 ... Steel tube, 10 ... Die roll surface 12 ... Rolled die, 14 ... Core metal

Claims (1)

(57) [Claims] 1. A method for manufacturing a deformed tube for a drive shaft, which is fitted in a female tube so as to be slidable in an axial direction, by using a rolling die, wherein two metals of a female and a female are formed before rolling. The tube is subjected to a coating treatment, and thereafter, the two metal tubes having been subjected to the coating treatment are fitted to each other and fitted into a metal tube of a mandrel corresponding to the inner surface of the inner male tube, and the female tube is Manufacturing of a deformed tube characterized by rolling from the outside of a female metal tube with a rolling die having a die rolling surface corresponding to the outer surface, and simultaneously rolling these fitted metal tubes into a deformed tube. Method.