JPH081210B2 - Manufacturing method of cylindrical member - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a cylindrical member that constitutes various rolls such as a developing roll and a fixing roll incorporated in an electrophotographic device, an electrostatic recording device, or the like.

[Conventional technology]

In an image forming apparatus such as an electrophotographic copying machine, a facsimile, a printer, etc., as a conveyance means of a magnetic developer such as a one-component magnetic toner or a two-component developer composed of a magnetic carrier and toner, for example, a developing roll or a cleaning roll, A magnet roll is often used in which a permanent magnet member having a plurality of magnetic poles is arranged inside a non-magnetic sleeve, and the two are relatively rotated.

An ordinary magnet roll is equipped with side plates (hereinafter referred to as flanges) made of a similar non-magnetic metal material at both ends of a cylindrical sleeve made of a non-magnetic metal material such as aluminum alloy, austenitic stainless steel or brass. It has a structure in which a permanent magnet member is supported by a flange via a bearing. As the permanent magnet member, a cylindrical magnet made of hard ferrite is fixed to the shaft (see, for example, Japanese Examined Patent Publication No. 55-6907), and a block-shaped anisotropic ferrite magnet is fixed to the periphery of the shaft (for example, actual Kosho). 57-9758), or those using a cylindrical resin magnet (see, for example, JP-A-57-130407).

In the above magnet roll, the sleeve has a diameter of about 20 to 60 mm and a length of about 200 to 400 mm, that is, an axial length / diameter of about 3 or more, which is extremely elongated. Further, the external magnetic field generated by the permanent magnet sharply decreases as the air gap increases. Therefore, in order to efficiently obtain the desired magnetic field strength on the sleeve, it is necessary to minimize the gap between the sleeve and the permanent magnet. . Therefore, in general magnet rolls, the wall thickness of the sleeve is about 1 to about 2 m.
It's thinned to m.

As described above, joining of the long and thin sleeve and the flange requires a pull-out strength of about 20 kg or more, and an adhesive is generally used to secure such joining strength. However, when using an adhesive, it is necessary to dry the adhesive after applying it or to remove the protruding adhesive, which has the drawback of increasing the number of steps for assembling the sleeve and the flange. .

In order to eliminate such a defect, mechanical joining of the sleeve and the flange has been proposed and partially put into practical use. As an example of mechanical joining, in Japanese Utility Model Laid-Open No. 57-22758, a recess is provided around the circumferential surface of the flange, the flange is fitted into the inner end of the sleeve, and the end surface of the sleeve is hydraulically pressed using a jig. It is disclosed that a device or the like narrows the flange in the direction of the recess and fits it into the recess.

Further, in the heat roll type fixing device, as a core of a heating roll or a pressure roll, a thin and long cylinder made of a metal material having good heat conductivity such as iron, aluminum alloy, and stainless steel is provided at both ends. A flange in which a shaft portion is joined by a method such as friction welding is used.

[Problems to be solved by the invention]

As described above, by squeezing the sleeve end surface toward the concave portion of the flange with a hydraulic device using a jig,
It is possible to join the sleeve and the flange relatively firmly without using an adhesive.

However, in such a joining method, when the sleeve is squeezed in the direction of the concave portion of the flange by a hydraulic device or the like, pressure distortion occurs in a portion other than the joint portion of the sleeve with the flange, and the outer diameter dimension of the sleeve changes. The problem occurs. Generally, due to the function of the magnet roll, the outer diameter of the sleeve needs to be within ± 0.05 mm of the standard value, but if the above processing distortion occurs, such dimensional accuracy can be maintained. Can not. Therefore, in the conventional mechanical joining method, it is necessary to grind the outer peripheral surface of the sleeve after joining so as to keep the outer diameter of the sleeve within a predetermined dimension.

Therefore, an object of the present invention is to provide a method for manufacturing a cylindrical member in which a cylindrical body and a flange are mechanically joined and which does not require outer peripheral processing after joining.

[Means for solving problems]

The present invention, in order to achieve the above object, in a cylindrical member having a flange made of a metal material mounted on one end of a thin and elongated cylindrical body made of a metal material that can be plastically worked,
A groove or protrusion in the circumferential direction is provided on the outer peripheral surface of the flange, the flange is fitted to one end of the cylindrical body, and the cylindrical body is passed through a die to uniformly reduce the diameter over the entire length. In addition, by adopting the technical means of biting the cylindrical body into the groove provided in the flange or biting the protrusion provided in the flange into the cylindrical body to integrally join the two. is there.

〔Example〕

In the present invention, the cylindrical body and the flange are integrated by cold forging. There are various methods for cold forging, but in the present invention, it is preferable to apply coining, which is a forging process for molding in a closed or semi-closed mold.
This coining is performed according to the following steps.

First, cut the metal tube, which is the material, to a specified length, and then perform preliminary upsetting to obtain the squareness of both ends of the material (it may be omitted when the squareness is shown). Annealing is performed to increase the plasticity of the and then coated with the lubricant. In this case, as the material of the metal tube, a soft and ductile material such as aluminum and its alloy is preferable from the viewpoint of cold forgeability. Also, other materials such as stainless steel and bearing steel can be cold forged when the amount of deformation is small, and even steel materials such as low carbon steel such as S10C to S25C or SCr 21, Scr 22, SCM21, SCM22 Alloy steels with a low carbon content such as can also be used. As the lubricant, a liquid lubricant is generally used in the case of a non-ferrous metal, and a combination of a phosphate coating and a soap treatment is used in the case of a steel material.

Next, the metal pipe prepared as described above and the flange having smooth grooves or protrusions on the outer peripheral surface thereof are set in a mold of a press machine and molded. Since the material of the press is long and slender, it is appropriate to use a low-speed hydraulic (hydraulic or hydraulic) press having a long stroke. In this case, insert the metal tube into the die, support the lower surface of the flange with the lower punch, and then
By ironing the metal tube and the flange, the wall thickness of the metal tube is thinned and the metal tube and the sleeve are joined by caulking and crimping. In order to obtain sufficient bonding strength in this forming step, it is important to set the cross-section reduction rate (S) of the metal tube represented by the following formula to an appropriate value.

S = (S ₁ −S ₂ ) / S ₁ × 100 (%) where S _{1 is} the cross-sectional area of the material before processing S _{2 is} the cross-sectional area of the material after processing S is the product dimension (length And diameter) to some extent, but it is desirable to set it in the range of 50 to 90%. A more preferable range is 60 to 75%.

After taking out the metal tube with a flange after molding from the mold,
A cylindrical member with a bottom is obtained by processing both ends of the metal tube and adjusting them to a predetermined length.

According to the above cold forging, since the metal pipe and the flange are joined while thinning the entire metal pipe, the outer diameter can be made uniform over the entire length, and distortion such as caulking is not substantially generated in the joint portion. Can be prevented. Further, by properly selecting the lubricant, the outer peripheral surface of the metal tube can be finely finished. In this cold forging, the materials of the metal tube and the flange do not have to be the same, and even if they are different, joining can be sufficiently performed. The flange is not limited to metal and may be a non-metal material such as plastic. Further, cold forging may be carried out after the bearing has been inserted into the flange in advance.

 Hereinafter, the present invention will be described more specifically with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a magnet roll incorporating a cylindrical member manufactured by the method of the present invention, and FIG. 2 is A- in FIG.
FIG.

In both figures, 1 is a magnet roll, and a magnetic body 3 formed by fixing a cylindrical permanent magnet 4 to a shaft 5 is arranged inside a sleeve 2 made of a non-magnetic metal material such as aluminum alloy or stainless steel. Formed. A sleeve driving flange 6 and a sleeve concentric holding flange 7 made of a non-magnetic metal material are mounted on both ends of the sleeve 2. Here, the flange 6 has a shaft 8 for transmitting a driving force from an external driving source (not shown) to the sleeve 2. Bearings 9 are fitted inside the flanges 5 and 6, respectively, and the bearings 9 support the reduced diameter portions 5a and 5b of the shaft 5. This allows the sleeve 2 and the magnet body 3 to rotate relative to each other.

This magnet roll 1 has a sleeve 2 and a flange 7.
Are joined together to produce the cylindrical member 10, the magnet body 3 is inserted into the cylindrical member 10, and then the sleeve 2 and the flange 6 are joined to assemble.

The procedure for producing the above cylindrical member 10 will be described with reference to FIGS. 3 and 4.

FIG. 3 is an exploded view of the cylindrical member 10 before processing, and FIG. 4 is a sectional view of a joint portion of the cylindrical member 10. As shown in FIG. 3, a metal tube 20 (diameter D ₁ ) made of an aluminum alloy (A3003), which is cut to a predetermined length and whose outer peripheral surface is coated with a lubricant (not shown)
And an aluminum alloy (A300
3) Prepare the flange 7 made of. Where the length L of the metal tube 20
₁ is shorter than the length L ₂ after processing, and its diameter D ₁ and wall thickness are larger than the diameter D ₂ and wall thickness after processing. The metal tube 20 and the flange 7 are set in a hydraulic press (not shown), and the flange 7 is inserted into one end of the metal tube 20. The press is operated so that the metal pipe 20 is spread and a part of the metal pipe 20 is cut into the annular groove 7a of the flange 7. As a result, as shown in FIG. 4, the sleeve 2 and the flange 7 are integrated into a predetermined size (total length).
A cylindrical member 10 with L _X and diameter D ₂ ) is obtained. In this case, the tolerance of the outer diameter can be kept within ± 0.05 m over the entire length, and by using an appropriate lubricant, the outer peripheral surface of the sleeve 2 can be
Since it can be finished to 6S to 9S or less (up to 1S is sufficiently possible), it is possible to omit peripheral polishing processing after joining.

In addition, in the present invention, as shown in FIG.
A cylindrical member 10 as shown in FIG. 6 is obtained by preparing a flange 7 having an annular projection 7b on the outer peripheral surface thereof, setting them in a hydraulic or hydraulic press, and then performing cold forging similar to the above. be able to.

Further, according to the present invention, the joint strength between the sleeve and the flange is sufficiently high (the pull-out strength is 200 kg or more), and it can be sufficiently used as it is. However, as shown in FIG. 7, the outer peripheral surface of the flange 7 is knurled, for example. The roughened surface is effective in increasing the joint strength between the sleeve 2 and the flange 7.

The present invention can be applied to products other than magnet rolls. For example, the metal core of the fixing roller can also be obtained by joining the shaft member to the one end of the metal pipe by the cold forging described above.

〔The invention's effect〕

As described above, according to the present invention, the cylindrical body and the support body are joined to each other by a specific machining process, and the outer peripheral process after the joining process is not required. Therefore, the number of assembling steps for various rolls such as a magnet roll can be reduced. Since the strength of the joint between the cylindrical body and the support is great, the reliability of the product can be improved.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a magnet roll using a cylindrical part manufactured by the method of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a cylinder manufactured by the method of the present invention. 4 is an exploded perspective view of a cylindrical part manufactured by the method of the present invention, FIG. 4 is an exploded perspective view of a cylindrical part manufactured by the method of the present invention, and FIG. FIG. 7 is a sectional view of a joint portion of a cylindrical part manufactured by the method of the present invention, and FIG. 7 is a perspective view showing another embodiment of the present invention. 2: Sleeve, 7: Flange, 7a: Annular groove, 7b; Annular protrusion, 1
0: Cylindrical part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsunobu Kiriyama 5200 Mikkajiri, Kumagaya City, Saitama Prefecture Inside the Kumagaya Factory, Hitachi Metals Co., Ltd. Within Seiko Co., Ltd. (56) Reference JP-A-58-52662 (JP, A) JP-A-60-217029 (JP, A) Practical development Sho-58-172113 (JP, U)

Claims (1)

[Claims] 1. A method of manufacturing a cylindrical member, comprising a thin and slender cylindrical body made of a metal material capable of being plastically worked, and a flange made of the metal material attached to one end of the elongated cylindrical body. A portion, and the flange is fitted to one end of the cylindrical body, the cylindrical body is passed through a die and squeeze cold forging to uniformly reduce the diameter over the entire length, and the groove is provided in the groove. A method for manufacturing a cylindrical member, characterized in that the cylindrical body is bited or a protrusion provided on the flange is bited into the cylindrical body to integrally join the two.