JP2000117375A - Grooving method of hollow columnar member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a groove in a circumferential surface of a hollow columnar member without deforming the member. SOLUTION: Firstly, a groove 2 is formed along a specified pattern 2M on one surface of a metallic sheet 1 in a grooving process. Then, the metallic sheet 1 is wound from one side of the rectangular-cut metallic sheet 1 to the other side on the opposite side into a cylindrical shape in a winding process. Finally, one side of the wound metallic sheet 1 is joined with the other side in a joining process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a groove in a hollow cylindrical member used for a sleeve or the like of a dynamic pressure bearing.

[0002]

2. Description of the Related Art Conventionally, dynamic bearings as shown in a partial sectional view of FIG. 3 have been used for bearings rotating at high speed and high precision. The shaft 101 is rotatably fitted to a sleeve 102, and a thrust plate 103 is fixed to a lower end of the sleeve 102. A shallow groove 104 is formed on the upper surface of the thrust plate 103 to form a dynamic pressure thrust bearing. A shallow groove 105 is also formed on the inner peripheral surface of the sleeve 102 to form a dynamic pressure radial bearing. In this dynamic pressure bearing 100, lubricating oil is injected into a gap 106 between a shaft 101 and a sleeve 102 which are relatively rotatably arranged. A dynamic pressure is generated in the lubricating oil by the pumping action of the grooves 105 and 104 provided on the inner peripheral surface and the bottom surface of the sleeve 102, and the shaft 101 and the sleeve 102 can be relatively rotated by the dynamic pressure.

FIG. 4 shows three examples of patterns of the dynamic pressure groove 105 formed on the inner surface of the sleeve 102 as (A) to (C). The dynamic pressure groove 105 is processed into a predetermined groove shape such as a herringbone shape or a spiral shape.

Conventionally, when forming a groove on the inner surface of a hollow cylindrical member such as a sleeve 102, a rolling process has been employed. The rolling process will be briefly described with reference to FIG. FIG.
Shows a sleeve 102 in which a plurality of substantially V-shaped dynamic pressure grooves 105 are formed on an inner peripheral surface 107, and a rolling machine 204 for processing the sleeve 102. The sleeve 102 is made of a hollow metal column made of SUS or the like. On the other hand, the rolling machine 204 includes a cylindrical portion 205 and a plurality of hemispherical projections 206 arranged at equal intervals in the circumferential direction. The hemispherical projection 206 can be made to come and go with respect to the cylindrical portion 205 by a pin or a hydraulic pressure (not shown). Further, the rolling machine 204 includes a feeding device and a rotating device (not shown),
The fourth cylindrical portion 205 can be inserted into the sleeve 102 and can be rotated in both forward and reverse directions while inserted into the sleeve 102.

In order to form a dynamic pressure groove 105 on the inner peripheral surface 107 of the sleeve 102, first, the sleeve 102 is fixed,
The feeder of the rolling machine 204 is driven so that the center axis of the cylindrical portion 205 and the center axis of the sleeve 102 coincide with each other.
Then, the rolling machine 204 is moved in the direction of, and the cylindrical portion 205 is inserted into the sleeve 102. When the cylindrical portion 205 is pushed into the sleeve 102 and reaches a predetermined position, the plurality of hemispherical projections 206 housed in the cylindrical portion 205 are inserted into the cylindrical portion 20.
The semi-spherical projection 206 is pressed into the inner peripheral surface 107 of the sleeve 102 so as to protrude from the outer peripheral surface of the sleeve 5. This press-fitting start point is the starting point for forming the dynamic pressure groove 105. Next, the cylindrical part 2
While moving 05, the cylindrical portion 205 is rotated in the direction B of FIG. Further, when the cylindrical portion 205 comes to a predetermined position while being advanced, the column portion 205 is reversely rotated in the direction of arrow C in FIG.
As a result, the trajectory of the hemispherical projection 206 becomes a substantially V-shaped dynamic pressure groove 105 as shown in FIG.

[0006]

In the conventional rolling technology described above, when the thickness of the hollow cylinder is thin, the hollow cylinder may be deformed by plastic deformation force after the dynamic pressure groove is rolled. Was. For this reason, there has been a problem that the shape and accuracy of the sleeve necessary for the fluid bearing cannot be secured.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems of the prior art, the following measures have been taken. That is, the groove processing method of the hollow cylindrical member according to the present invention is performed by the following steps. First, a groove forming step is performed to form a groove on one surface of a metal plate material along a predetermined pattern. Next, a winding step is performed, and the metal sheet is wound into a cylindrical shape from one side of the rectangularly cut metal sheet toward the other side on the opposite side. Finally, a joining step is performed to join one side and the other side of the wound metal plate material.

Preferably, in the groove forming step, a groove is formed on one surface of the metal plate material by etching, rolling or pressing. More preferably, in the groove forming step, a groove is formed on one surface of the metal sheet material using a rolling roller, and in the winding step, the metal sheet material is wound into a cylindrical shape using the rolling roller as it is. . In one embodiment, in the winding step, the metal plate is wound with one surface on which the groove is formed inside, so that the groove appears on the inner surface of the cylinder. In another embodiment, in the winding step, the metal plate material is wound with one surface on which the groove is formed outside, so that the groove appears on the outer surface of the cylinder. Such a method of forming a groove in a hollow cylindrical member can be applied to, for example, processing of a sleeve of a dynamic pressure bearing.

According to the present invention, first, a groove is formed on one surface of a metal plate material. Thereafter, the metal plate is processed into a cylindrical shape, and both ends are joined. Instead of processing the groove on the inner peripheral surface of the hollow cylindrical member as in the related art, the groove is processed first, and then the metal plate material can be accurately processed into a cylindrical shape.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a process chart showing a method for processing a groove in a hollow cylindrical member according to the present invention. First, a groove forming step is performed, and a groove 2 is formed on one surface of the metal plate material 1 along a predetermined pattern. In this groove forming step, etching, rolling, or pressing can be used. (A
1) shows a groove forming step by etching. In this case, one surface of the metal plate 1 is etched using a mask M on which a predetermined pattern 2M has been drawn in advance. When a sleeve of a dynamic pressure bearing is made using the metal plate material 1,
The thickness of the metal plate 1 is, for example, about 10 mm, and SUS, Al, phosphor bronze, or the like is used as a material. Further, as the pattern 2M of the dynamic pressure groove, various shapes such as a herringbone pattern and a spiral pattern capable of generating a dynamic pressure can be adopted. When SUS is used as the metal plate material 1 and the groove 2 is formed by chemical etching, ferric chloride can be used as an etching solution.

(A2) schematically shows a groove forming step utilizing rolling. In this case, the projection 2 of the predetermined pattern
T using a rolling roller T having an outer peripheral surface
The groove 2 is rolled on one side.

(A3) schematically shows a groove forming step using press working. The groove 2 is transferred to one surface of the metal plate 1 using a press die P on which a predetermined pattern is formed in advance. As described above, in any case of etching, rolling or pressing, the grooves are formed on the flat surface of the metal plate material, so there are structural restrictions compared to the case of forming grooves on the inner surface of the cylinder as in the past. Absent. Therefore, an optimum processing method can be adopted according to the material of the metal plate material and the required processing accuracy of the groove.

Next, a winding step is performed, and the metal plate 1 is wound from one side of the rectangularly cut metal plate 1 to the other side on the opposite side, and is processed into a cylindrical shape. In the example shown in (B1), the metal plate material 1 is wound up using the roller R with one surface on which the groove 2 is formed inside, so that the groove appears on the inner surface of the cylinder. In some cases, as shown in (B2), the metal plate 1 may be wound so that one surface on which the groove 2 is formed is outside, and processing is performed so that the groove appears on the outer surface of the cylinder.

(B3) is to form a groove 2 on one surface of the metal plate material 1 using a rolling roller T, and then take up the metal plate material 1 using the rolled roller 2 as it is to process it into a cylindrical shape. It is.

Finally, a joining step is performed as shown in FIG. 1C, and one side and the other side of the wound metal plate 1 are joined to each other. In the illustrated example, the end 1a of the wound metal plate material 1 is cut along the uneven line 3. Although not shown, the end of the metal plate 1 on the winding start side is also cut in advance so as to be aligned with the uneven line 3. Rolled metal plate 1
Are fitted to each other along the uneven line 3 to complete a cylindrical shape. In addition, in this example, the cutting process of the rear end part 1a which wound the metal plate material 1 in a cylindrical shape is performed in order to make it easy to understand. Alternatively, the metal plate 1 may be wound up.

FIG. 2 is a schematic diagram specifically showing a groove forming step using etching. First, as shown in (A), a photoresist is coated on a metal plate material 1 and a mask M is applied.
And Next, as shown in (B), the photoresist is exposed and developed along a predetermined pattern, and a predetermined pattern 2M is opened in the mask M. Next, as shown in (C), the surface of the metal plate 1 is chemically etched through a mask M having an opening to form a groove 2. Metal plate 1
In the case where SUS is used, a ferric chloride solution can be used as an etching solution. Finally, as shown in (D),
The used mask M is peeled off from the surface of the metal plate material 1 and removed. Although the pattern is formed on the mask M using photolithography in this example, the mask M may be formed on the metal plate material 1 by printing or the like instead.

[0017]

As described above, according to the present invention,
After forming a groove along a predetermined pattern on one surface of the metal plate material, the metal plate material was wound into a cylindrical shape from one side of the rectangularly cut metal plate material toward the other side on the opposite side, and then wound. By joining one side and the other side of the metal plate to each other, the groove processing of the hollow cylindrical member is realized. Thereby, the groove processing can be performed without causing deformation of the hollow cylindrical member. Even when a groove is formed on the inner or outer peripheral surface of the hollow cylindrical member, an appropriate groove forming method can be selected without any structural restrictions.

[Brief description of the drawings]

FIG. 1 is a process chart showing a method for forming a groove in a hollow cylindrical member according to the present invention.

FIG. 2 is a process diagram showing an etching process used in a groove forming step included in the groove processing method for a hollow cylindrical member according to the present invention.

FIG. 3 is a schematic partial sectional view showing an example of a conventional dynamic pressure bearing.

FIG. 4 is a schematic plan view showing an example of a pattern of a dynamic pressure groove formed on an inner surface of a sleeve included in the dynamic pressure bearing shown in FIG.

FIG. 5 is a schematic view showing a method of forming a dynamic pressure groove by rolling on an inner surface of a sleeve used in the dynamic pressure bearing shown in FIG. 3;

[Description of Signs] 1 ... Metal plate material 2 ... Groove 2M ... Pattern 2T ... Protrusion M ... Mask P ... Press die R ... Roller T ... Rolling roller

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Isamu Takehara 1-8-1, Nakase, Mihama-ku, Chiba City, Chiba Prefecture Inside of Eiko Instruments Inc. (72) Inventor Yukihiro Nakayama 1-8, Nakase, Nakase, Mihama-ku, Chiba City, Chiba Prefecture Ricoh Yoneyama, inventor Ryoji Yoneyama 1-8-1, Nakase, Mihama-ku, Chiba-shi, Chiba Seiko Instruments Inc. (72) Inventor Ritsuharu Smaller 1-8, Nakase, Nakase-Mihama-ku, Chiba-shi Seiko Inside Instruments Co., Ltd. (72) Inventor Tadao Iwaki 1-8-8 Nakase, Mihama-ku, Chiba City, Chiba Prefecture Inside Seiko Instruments Inc. (72) Naoki Kawawada 1-8-8 Nakase, Mihama-ku, Chiba City, Chiba Seiko Instruments Inc In-company (72) Invention Person Atsushi Ota 1-8-8 Nakase, Mihama-ku, Chiba City, Chiba Prefecture Inside Seiko Instruments Inc. (72) Inventor Koji Nitori 1-8-8 Nakase, Mihama-ku, Chiba City, Chiba Prefecture Seiko Instruments Inc. F-term (reference) 3J011 AA04 AA20 BA02 CA02 DA02

Claims (6)

[Claims] A groove forming step of forming a groove on one surface of the metal plate along a predetermined pattern; winding the metal plate from one side of the rectangularly cut metal plate to the other side on the opposite side; A groove processing method for a hollow cylindrical member, comprising: a winding step of processing into a shape; and a joining step of joining one side and the other side of the wound metal plate material to each other. 2. The groove forming step includes forming a groove on one surface of the metal plate material by etching, rolling or pressing.
The method for processing a groove of a hollow cylindrical member according to the above. 3. The groove forming step includes forming a groove on one surface of the metal sheet using a rolling roller, and the winding step uses the rolling roller to wind the metal sheet into a cylindrical shape. Item 6. The method for processing a groove in a hollow cylindrical member according to Item 1. 4. The method according to claim 1, wherein in the winding step, the metal plate is wound with one surface having the groove formed therein, so that the groove is formed on the inner surface of the cylinder. . 5. The method according to claim 1, wherein in the winding step, the metal plate is wound with one surface on which the groove is formed facing outward, so that the groove appears on the outer surface of the cylinder. . 6. The method according to claim 1, wherein the sleeve of the dynamic pressure bearing is formed by a groove forming step, a winding step, and a joining step.