JPH01238709A - Manufacture of hollow shaft - Google Patents

Abstract

PURPOSE:To improve the productivity of a hollow shaft in its manufacture, which becomes the base part of a rubber roller for a copying machine or the like by integrally forming a shaft body by forging, cutting the engaging area of the shaft body, and engaging the engaging part into a pipe so as to joint them by spot welding. CONSTITUTION:Each shaft body 1, 2 which is composed of a shaft part and an engaging part, is integrally formed by forging, and each engaging part 1a, 2a of the shaft bodies 1, 2 is shaped by cutting. The engaging parts 1a, 2a of the shaft bodies 1, 2 are engaged info a pipe 3 so that spot welding SW is conducted to joint the shaft bodies 1, 2 with the pipe 8. Consequently, number of the cutting processes can be reduced so that the productivity of the hollow shaft improved.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing a hollow shaft having shaft portions at both ends.

<Prior Art> Rubber rollers used in office automation equipment such as copying machines and printers are generally formed by providing a rubber cylinder portion around the outer periphery of a hollow shaft.

A hollow shaft serving as a base of a rubber roller has conventionally been manufactured as shown in FIGS. 4, 5, and 6.

In the method shown in FIG. 4, shafts 101 and 102 that have been roughly formed by forging are joined to both ends of a steel pipe 103 by friction welding, and then the shafts 101 and 102 are machined. be. In the figure, A indicates a friction welding portion, and two-dot chain lines indicate the outlines of the shaft bodies 101 and 102 before cutting.

The method shown in FIG. 5 uses a shaft 104 obtained by cutting.
, 105 are press-fitted to end members 106 made of aluminum alloy, and each end member 106 with integrated shafts 104 and 105 is further press-fitted into both ends of a pipe 103 made of steel.

In the method shown in FIG. 6, a deformed pipe 108 having a press-fit cylindrical portion 107 of the shaft is formed by extrusion molding, and pipe press-fit holes 109 are formed at both ends of the press-fit cylindrical portion 107 of this pipe 108.
The shafts 104 and 105 obtained by cutting are press-fitted into these pipe press-fit holes 109.

<Problems to be Solved by the Invention> However, the method shown in FIG. 4 has a problem in that the number of man-hours for cutting is large and productivity is poor.

Furthermore, the method shown in FIG. 5 requires two types of press-fitting processes: the shaft 104° 105 and the end member 106, and the end member 106 and the pipe 103, which is undesirable in terms of manufacturing man-hours.
Further, since the end member 106 is required, there arises a problem that the number of parts increases.

The method shown in FIG. 6 requires extrusion molding into a special shape, resulting in high manufacturing costs and material costs.

Furthermore, in any of the above methods, the strength of the connection between the shaft body or the shaft and the pipe depends only on friction welding or press fitting, and to supplement the strength, another method such as pin driving is required. It becomes necessary.

In addition, in each of the above methods, the shaft bodies 101, 102, the shaft 10
4,105 is cleaned by cutting, so
If the shaft portion requires a complicated shape such as an irregular cross section, there is a problem that the cutting process becomes complicated.

Means for Solving the Problems> A method for manufacturing a hollow shaft according to the present invention that solves the above problems is a method for manufacturing a hollow shaft having shaft portions at both ends, which comprises a shaft portion and a fitting portion. The shaft body is integrally formed by forging, the fitting part of the shaft body is cut to match the pipe, the cut fitting part is fitted to the end of the pipe, and the pipe and the fitting part are connected. It is characterized by being joined by spot welding.

Embodiment FIG. 1 shows a partial cross section of a hollow shaft obtained by a method according to an embodiment of the present invention, and FIGS. 2 and 3 show a shaft body. Note that this embodiment is applied to a hollow shaft for a printer platen.

The shaft bodies 1 and 2 shown in FIGS. 2 and 3 are each formed by forging. The shaft body 1 consists of a large-diameter fitting part 1a, a round shaft part 1b with a circular cross section integral with it, and a square shaft part IC with a hexagonal cross section continuous with the round shaft part 1b, and is cold forged. Alternatively, it can be formed with high precision by warm forging.

Components are fitted into the round shaft portion 1b and the square shaft portion IC, but the precision for this is obtained only by forging.

The fitting portion 1a of the shaft body 1 is connected to the pipe 3 (
(e.g., made of steel), the ends may be machined for abutting fit. Fitting part 1d according to the inner diameter of pipe 3
is machined, and following this fitting part 1d, a contact part 1e applied to the end of the pipe 3 is machined. Note that, if necessary, the round shaft portion 1b and the like are also subjected to cutting (for example, the groove If in the figure). Figure 2 (al
In , the shape after cutting is indicated by a two-dot chain line.

The other shaft body 2 consists of a large-diameter fitting part 2a and a shaft part 2b integrated therewith.The shaft part 2b, like the shaft parts 1b and lc of the shaft body 1, is fully formed by forging. High accuracy has been achieved, and subsequent machining is not required.

Similarly to the fitting part 1a of the shaft 1, the fitting part 2a of the shaft 2 is also machined to have a fitting part 2C to the end of the pipe 3 and a contact part 2d to the end surface of the pipe 3. In Figs. 3f and 3, the cut shape is indicated by a two-dot chain line.

The shaft bodies 1 and 2 obtained as described above are fitted into contact with both ends of a pipe 3, as shown in FIG. Shaft 1, 2
The fitting parts 1a, 2a and the fitting parts 1d, 2c of the pipe 3
It is fitted into the inner diameter of the end portion, and the contact portions 1e and 2d are brought into contact with the end surface of the pipe 3.

Next, the end portion of the pipe 3 is diametrically held between spot welding electrodes, and the fitting portions 1d and 2c of the pipe 3 and the shaft bodies 1 and 2 are
Pipe 3 is spot welded at two locations in the diametrical direction.
and the shaft body 1°2 are joined. In Figure 1, SW
indicates a spot weld.

Through the above process, a hollow shaft having shaft portions at both ends can be obtained. When this hollow shaft is used as a rubber roller for a platen of a printer, a rubber roller portion is provided on the outer peripheral surface of the pipe 3 in the next step.

The above-mentioned embodiment is just an example, and the shape of the shaft body 1゜2 is not limited to the above-mentioned shape, but may have various shapes as necessary, for example, the cross-sectional shape may be a flower pattern, a square, or a rectangle. etc. are obtained by forging and used.

<Effects of the Invention> According to the method for manufacturing a hollow shaft according to the present invention, a shaft body having a shaft portion is obtained by forging, and cutting of the shaft portion is not required, and only the fitting portion with the pipe is cut. In particular,
The number of cutting parts is kept to a minimum, and the pipe and shaft are joined by spot welding, which improves productivity and enables mass production of hollow shafts. At the same time, manufacturing costs can also be reduced.

Furthermore, since the shaft body is obtained by forging, it is also possible to mass produce shafts with complex shapes such as polygonal shapes. Furthermore, since the shaft and the pipe are fitted together and then spot welded, a hollow shaft with excellent strength can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of a hollow shaft obtained by a method according to an embodiment of the present invention, FIG. A front view and a side view of the other shaft, FIG. 4. FIGS. 5 and 6 are cross-sectional views of the hollow shaft obtained by the conventional manufacturing method. In the drawings, 1 is the shaft. , 1a+ is a fitting part, lb and lc are shaft parts, 2 is a shaft body, 2al is a fitting part, 2b is a shaft part, 3 is a pipe, and SW is a spot welding part.

Claims (1)

[Claims] A method of manufacturing a hollow shaft having shaft parts at both ends, in which a shaft body consisting of a shaft part and a fitting part is integrally formed by forging, the fitting part of the shaft body is cut to fit the pipe, and the fitting part is cut to fit the pipe. A method for manufacturing a hollow shaft, comprising fitting a processed fitting part to an end of a pipe, and joining the pipe and the fitting part by spot welding.