JPH03248711A - Manufacture of special shaped tube - Google Patents

Abstract

PURPOSE:To easily manufacture a special shaped tube of a few idle space and a long durable life at a low cost by utilizing the dies corresponding to the female tube and the metal core corresponding to the male tube and drawing the two pieces of the metallic tubes mutually fitted at the same time. CONSTITUTION:On the case to manufacture the special shaped tube consisting of the male tube 2 and the female tube 4 of the star shaped tubes manufactured of the machine structural carbon steel pipe, the dies 6 and the core metal 8 are utilized. These tubes are fitted mutually, and the end parts of these tubes are made slender and formed to a tapered shape as like as shown with the dotted lines 10, 12. The core metal 8 is inserted inside the male tube 2 and these tubes are inserted from their tapered ends into between the dies 6 and the core metal 8. Next, the male tube 2 and the female tube 4 are drawn against the core metal 8 and the dies 6. Therefore, the special shaped tube of little idle space, being noiseless because of smooth sliding in the axial direction on the power transmitting time and having the long durability can be easily manufactured at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for manufacturing a deformed tube consisting of a hollow male shaft and a female shaft that are fitted together so as to slide against each other in the axial direction.

(Prior art and its problems) This type of irregularly shaped tube is used, for example, in a joint assembly consisting of two universal joints, in which the male shaft is located within the female shaft so that they do not rotate around each other's axes. Those with a lemon-shaped or star-shaped cross section are used.

In order to manufacture these irregularly shaped tubes, the male and female shafts are manufactured separately by mechanically forming the metal tube or by broaching, etc., and the male and female shafts are slidably fitted together. The gaps were corrected manually. Therefore, not only does it take a lot of time to manufacture, but there is also a lot of play between the male and female shafts, which makes noise during operation, and is prone to galling and seizure, and the conduction efficiency of universal joints that use irregularly shaped tubes. It had the disadvantages of low energy consumption and short service life.

Therefore, there has been a long-awaited demand for a deformed tube that can be manufactured in a short time and at low cost, has no play in fitting the male shaft and female shaft, operates without galling or seizing, and has a long service life.

(Means for Solving the Problems) In order to solve this problem, the method for manufacturing an irregularly shaped tube of the present invention is based on the above-mentioned method for manufacturing an irregularly shaped tube in which a tube is inserted into the tube so that it can slide in the axial direction. The method is characterized in that two metal tubes fitted into each other are simultaneously drawn out using a die corresponding to the female tube and a mandrel corresponding to the male tube.

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

(Function) By simultaneously pulling out two metal tubes that fit into each other, an irregularly shaped tube with no mutual play can be manufactured in a short time. If the two metal tubes were machined or broached separately, it would take time to adjust them after machining, and the play could not be completely removed, but by pulling them out at the same time, it can be done in a short time with less man-hours. It is possible to manufacture irregularly shaped tubes.

(Example) As an example of a deformed tube, a part is shown in a perspective view in FIG. 1, and an end face is shown in FIG. 2.

The irregularly shaped tube of this embodiment is a star-shaped tube manufactured from a carbon steel pipe for mechanical structures, and is composed of a male tube 2 and a star tube 4. The carbon steel pipe may be a seamless steel pipe with a circular cross section or a seamless steel pipe with a circular cross section. Further, although the illustrated irregularly shaped tube has a star shape, a triangular or square irregularly shaped tube may also be used.

In manufacturing this irregularly shaped tube, the present invention uses a die 6 and a mandrel 8 as shown in FIG. The inner and outer surfaces of the steel pipe that will become the male tube 2 and the steel pipe that will become the male tube 4 are first subjected to caustic treatment such as phosphate coating treatment. Alternatively, it may be coated with molybdenum disulfide or tungsten disulfide. Further, this treatment may be omitted for the inner surface of the male tube.

Next, these tubes are fitted together and shown in dotted line 10 in FIG.
The ends of these tubes are narrowed and tapered as shown at 12. A mandrel 8 is placed inside the male tube 2, and these tubes are inserted between the die 6 and the mandrel 8 from their tapered ends.

The circle indicated by dotted lines 10 and 12 is slightly smaller than the virtual circle inscribed and circumscribed on the inside of the die 6 and on the outside of the mandrel 8.

Next, the male tube 2 and the female tube 4 are pulled out from the mandrel 8 and the die 6. This drawing may be done by so-called cold drawing at room temperature, or in some cases from 200°C to 50°C.
Warm drawing at 00°C may also be used.

Although this embodiment describes the case of steel pipes, it goes without saying that other metal pipes such as steel pipes and aluminum pipes may also be used.

In this way, by simultaneously drawing out the male tube 2 and the male tube 4 using the die 6 and the mandrel 8, a deformed tube can be easily manufactured.

(Effects) As is clear from the above, according to the present invention, by pulling out the male tube 2 and the male tube 4 that are fitted into each other with respect to the die 6 and the mandrel 8, play can be reduced. Therefore, it is possible to easily and inexpensively manufacture a deformed tube that slides smoothly in the axial direction during power transmission, does not generate noise, and has a long life.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an irregularly shaped tube manufactured by the method of the present invention, Fig. 2 is an end view of the irregularly shaped tube of Fig. 1, and Fig. 3 is an end view showing the irregularly shaped tube during manufacture together with a die and a mandrel. . 2... Male tube 4... Female tube 6.
...Dice 8...Core 10, 12...Tapered end of metal tube before bow 1 is extracted Fig. 1 Fig. 2 Fig. 3

Claims (1)

[Claims] 1. In manufacturing a deformed tube in which a tube is fitted into a female tube so as to be able to slide in the axial direction, a die corresponding to the female tube and a center corresponding to the male tube are provided. A method for producing an irregularly shaped tube, characterized by simultaneously pulling out two metal tubes fitted together using gold. 2. The method according to claim 1, wherein a coating treatment is performed before the two metal tubes are pulled out.