JP2008126303A - Apparatus and method for working fine recessed part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for working fine recessed parts with which the fine recessed parts are formed with regular arrangement in the arrangement in a direction along the axial line of circular surface to be worked and the fine recessed parts having the desired shape are highly accurately formed by eliminating the effect caused by a spring-back of a material. <P>SOLUTION: The apparatus for working fine recessed parts is provided with: a form-roller 11 having projecting part 11a for forming the fine recessed part; an arm 12 for supporting the form-roller 11 freely rotatably with a rotating-shaft 14 crossing the inner circumferential surface Ba at the right angle; a tool holder 10; a helical compression spring 18 for press-contacting the form-roller 11 with the inner circumferential surface Ba; and a table 4 for shifting a cylinder block CB; wherein the projecting part of the form-roller has the shape assuming the spring-back rate of the material of the cylinder block CB and thus; the fine recessed parts P are formed with the regulating arrangement and the effect caused by the spring-back is eliminated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is, for example, an oil sump for realizing low friction on a circumferential work surface such as a sliding surface of a camshaft or a cylinder block in an automobile engine, that is, an outer peripheral surface of a journal or an inner peripheral surface of a cylinder bore. The present invention relates to a fine recess processing apparatus and a processing method used to form a large number of functioning fine recesses.

  As this type of fine recess processing apparatus, a circumferentially processed workpiece such as an outer peripheral surface of a cylindrical portion or an inner peripheral surface of a circular hole in a workpiece is provided with a foam roller having a convex portion for forming a fine recess on the outer peripheral portion. In some cases, the workpiece and the foam roller are arranged so that the axis of the surface is parallel to the rotation axis of the foam roller.

  In the fine recess processing apparatus described above, when the circumferential workpiece surface is the outer circumferential surface of the cylindrical portion of the workpiece, as shown in Patent Document 1, the foam roller is pressed against the circumferential workpiece surface. By rotating the work piece about the axis of the circumferential work surface, the foam roller rolls to form fine recesses, and the circumferential work surface is a circular hole in the work piece. In the case of the inner peripheral surface, as shown in Patent Document 2, the foam roller is pressed against the circumferential workpiece surface, and the tool holder that holds the foam roller is moved around the axis of the circumferential workpiece surface. By rotating the foam roller, the foam roller is rolled to form a fine recess.

Since the formation of the fine concave portion using such a foam roller is a machining process, the fine concave portion can be formed with high accuracy and efficiency compared to the case where the fine concave portion is formed by shot blasting, for example. This is very effective in improving productivity and reducing manufacturing costs.
JP 2005-169596 A JP 2005-319476 A

  However, in the conventional fine recess processing apparatus as described above, the foam roller is rolled around the axis of the circumferential workpiece surface of the workpiece, so the diameter of the circumferential workpiece surface and the diameter of the foam roller are Depending on the dimensional relationship, there is a problem in that the arrangement of the fine recesses in the arrangement in the direction along the axis of the circumferential workpiece surface causes a deviation in the circumferential direction, which makes it impossible to sufficiently reduce the sliding resistance. In addition, there is a problem that the desired shape of the fine recess, that is, a defined shape that can sufficiently reduce the sliding resistance, cannot be obtained by the spring back of the material of the workpiece, and these problems can be solved. It was a challenge.

  The present invention has been made in view of the above-described conventional situation. In the arrangement in the direction along the axis of the circumferential workpiece surface, the fine recesses can be formed in a regular arrangement, and It is an object of the present invention to provide a fine recess processing apparatus and a processing method capable of eliminating the influence of the material of the workpiece by the spring back and forming a fine recess having a desired shape with high accuracy.

  The fine recess processing apparatus of the present invention is an apparatus that forms a large number of fine recesses on a circumferential workpiece surface that is an outer peripheral surface of a cylindrical portion or an inner peripheral surface of a circular hole in a workpiece. Further, a foam roller having a convex part for forming a fine concave part on the outer peripheral part, a roller support member that rotatably supports the foam roller by a rotation axis orthogonal to the axis of the circumferential surface to be processed, and a roller support member are held. A tool holder, a load applying means for applying a load to the roller support member to press the convex portion of the foam roller against the circumferential workpiece surface, and at least one of the workpiece and the tool holder is a circumferential workpiece surface In addition to providing an axial direction moving means for moving in the direction along the axis, the convex portion of the foam roller has a shape that allows for the amount of spring back of the material of the workpiece, and the above configuration solves the conventional problems As a means to do.

  Further, the fine recess processing method of the present invention is a foam roller formed on the circumferential work surface when the fine recess is formed on the circumferential work surface of the workpiece using the fine recess processing apparatus as described above. In a direction along the axis of the circumferential workpiece surface by rolling the foam roller by moving at least one of the workpiece and the tool holder along the axis of the circumferential workpiece surface. It is characterized by continuously forming fine recesses.

  According to the fine recess processing apparatus and the processing method of the present invention, the fine recesses can be efficiently formed in a regular arrangement in the arrangement in the direction along the axis of the circumferential workpiece surface, and the workpiece The effect of the springback of the material can be eliminated, and the fine concave part with the specified shape can be formed with high precision, and the sliding resistance of the sliding surface, which is the work surface, is sufficiently reduced. A member can be provided.

  Hereinafter, an embodiment of a fine recess processing apparatus and a processing method of the present invention will be described with reference to the drawings. The detailed configuration of the present invention is not limited to the following examples.

  A fine recess processing apparatus 1 shown in FIG. 2 is an NC machine tool that forms a fine recess P on an inner peripheral surface Ba of a cylinder bore B in a cylinder block CB of an automobile engine, and includes a spindle head 2 that can be raised and lowered in a vertical direction, A spindle 3 supported in a suspended state from the spindle head 2, a workpiece placing table 4 movable in two axial directions perpendicular to each other in a horizontal plane below the spindle head 2, and coaxially mounted on the spindle 3 And a tool holder 10 that rotates integrally. The cylinder block is positioned on the workpiece placement table 4 with the axis of the cylinder bore B being vertical.

  As shown in FIG. 1, the tool holder 10 has a body portion 10A that is an attachment portion to the main shaft 3, and a convex portion for forming a fine recess is formed on the outer peripheral portion below the body portion 10A. An arm 12 as a roller support member that rotatably supports the foam roller 11 by a rotating shaft 14 orthogonal to the axis of the cylinder bore B, and a housing 13 that serves as a holding portion of the arm 12 in the tool holder 10. It is.

  The material of the foam roller 11 is not particularly limited. For example, the foam roller 11 is made of carbide, a hard metal other than carbide, ceramics such as alumina or silicon nitride, and is smaller than the diameter of the cylinder bore B. It has a diameter. As shown in FIG. 3, the foam roller 11 has a large number of convex portions 11a for forming fine concave portions at regular intervals on the outer peripheral portion. And the convex part 11a of the form roller 11 becomes a shape which anticipated the springback amount of the material of a workpiece (cylinder block CB) so that it may explain in full detail later.

  The arm 12 includes a rotary shaft 14 that is perpendicular to the main shaft 3, that is, horizontal to the main shaft 3 whose axis is vertical, and the foam roller 11 is rotatably supported by the rotary shaft 14. The housing 13 has a hollow block shape, and a spline nut 15 having an axial line in the horizontal direction is fitted and fixed to the hollow portion on the lower end side. The spline nut 15 and the spline connected to the arm 12 are fixed. The arm 12 is held so as to be movable in a horizontal direction perpendicular to the main shaft 3 by spline-bonding the shaft 16 to each other.

  A compression coil spring 18 is interposed between the arm 12 and the cap 17 fitted in the hollow portion on the upper end side of the housing 13, and applies a horizontal load perpendicular to the main shaft 3 to the arm 12. Thus, the convex portion of the foam roller 11 is brought into pressure contact with the inner peripheral surface Ba of the cylinder bore B. In this case, a piezoelectric load cell 19 as a load detecting means is provided between the cap 17 and the compression coil spring 18.

  Further, on the opposite side of the arm 12 of the spline shaft 16 in the housing 13, a stopper 20 made of a soft material such as urethane resin and having a diameter larger than that of the spline shaft 16 is fixed. In addition, the expansion of the compression coil spring 18 is suppressed, the impact when the compression coil spring 18 is fully extended is alleviated, and the arm 12 is prevented from falling off the housing 13.

  Further, an adjustment piece 21 for applying a preload to the compression coil spring 18 is provided between the compression coil spring 18 and the load cell 19, and the length of the adjustment piece 21 (the length of the compression coil spring 18 in the expansion / contraction direction) is set. The preload can be adjusted by selecting. Note that the load cell 19 has a spherical protrusion at the contact portion 19a with the adjustment piece 21, so that the compression coil spring 18 can be absorbed in the expansion and contraction direction.

  In this embodiment, the cylinder block CB corresponds to a workpiece, and the inner peripheral surface Ba of the cylinder bore B corresponds to a circumferential workpiece surface that is an inner peripheral surface of a circular hole in the workpiece. Further, in this embodiment, the compression coil spring 18 applies a load to the roller support member (arm 12) to cause the convex portion 11a of the foam roller 11 to become a circumferential work surface (inner peripheral surface Ba of the cylinder bore B). This corresponds to a load applying means for pressure contact.

  Furthermore, in this embodiment, the spindle head 2 that moves up and down in the vertical direction is arranged such that at least one of the workpiece (cylinder block CB) and the tool holder 10 is an axis of a circumferential workpiece surface (inner circumferential surface Ba of the cylinder bore B). The tool holder 10 is moved in the vertical direction here. Furthermore, in this embodiment, the main shaft 3 rotates at least one of the workpiece (cylinder block CB) and the tool holder 10 around the axis of the circumferential workpiece surface (inner circumferential surface Ba of the cylinder bore B). The tool holder 10 is rotationally driven here.

  Furthermore, in this embodiment, the workpiece mounting table 4 that moves in the horizontal direction is arranged such that at least one of the workpiece (cylinder block CB) and the tool holder 10 is a circumferential workpiece surface (the inner circumferential surface Ba of the cylinder bore B). ) In the radial direction, and corresponds to radial movement means for pressing the convex portion 11a of the foam roller 11 against the circumferential workpiece surface (inner circumferential surface Ba of the cylinder bore B). CB) is moved. This radial direction moving means can be used in combination with a load applying means (compression coil spring 18) having the same function, or can be used in place of the load applying means.

  In the fine recess processing apparatus 1 described above, when forming the fine recess P on the inner peripheral surface Ba of the cylinder bore B, first, positioning is performed so that the main shaft 3 and the axis (center line) of the cylinder bore B coincide on the same axis. Then, the tool holder 10 is lowered together with the spindle head 2, and the foam roller 11 is inserted into the cylinder bore B.

  Next, the table 4 is operated to bring the foam roller 11 into contact with the inner peripheral surface Ba of the cylinder bore B, and the movement of the table 4 is continued until the load detected by the load cell 19 reaches a preset value.

  That is, after the foam roller 11 comes into contact with the inner peripheral surface Ba of the cylinder bore B, if the movement of the table 4 is continued, the compression coil spring 18 is compressed between the arm 12 and the housing 13, and the repulsive force is used as a load. Since this load is detected by the load cell 19 at the same time that it is applied to the foam roller 11, if the movement of the table 4 is continued until the detected load of the load cell 19 reaches a set value, the inner peripheral surface Ba of the cylinder bore B Can be pressurized with a predetermined load.

  When the set value of the load is detected as described above, when the movement of the table 4 is stopped and the tool holder 10 is lowered together with the spindle head 2, the foam roller pressed against the inner peripheral surface Ba of the cylinder bore B As the foam roller 11 rolls, a row of fine recesses P are continuously formed on the inner peripheral surface Ba of the cylinder bore B over the axial direction. At this time, the row of fine recesses P is formed without shifting in the circumferential direction.

  Next, the foam roller 11 is separated from the inner peripheral surface Ba of the cylinder bore B by the movement of the table 4, and the tool holder 10 is rotated by a predetermined angle by the main shaft 3. Then, when the table 4 is operated, the foam roller 11 is again pressed against the inner peripheral surface Ba of the cylinder bore B with a set load, and the tool holder 10 is raised together with the spindle head 2, it is pressed against the inner peripheral surface Ba of the cylinder bore B. As the foam roller 11 moves up, the foam roller 11 rolls, and the next row of fine recesses P is continuously formed on the inner peripheral surface Ba of the cylinder bore B along the axial direction.

  By repeatedly performing these operations, as shown in FIG. 7, in the wide area of the inner peripheral surface Ba of the cylinder bore B, the axial direction (the vertical direction in FIG. 7) and the circumferential direction (the horizontal direction in FIG. 7) are regular. It is possible to form the fine recesses P arranged in the.

  Here, the convex portion 11a of the foam roller 11 has a shape that allows for the springback amount of the material of the workpiece (cylinder block CB) as described above. Specifically, as shown in FIG. 7, when the shape of the fine concave portion P is a rectangular shape having the long side in the circumferential direction of the cylinder bore B, the convex portion 11 a is formed as shown in FIGS. ), When the radius of curvature r of the long side of the tip is made smaller than the radius of curvature R of the inner peripheral surface Ba of the cylinder bore B and the foam roller 11 is pressed against the inner peripheral surface Ba of the cylinder bore B, The inner side of both end portions of the portion 11a is pressed deeper against the inner peripheral surface Ba.

  On the other hand, FIG. 6 is a diagram showing a case where the curvature radius r of the long side of the convex portion 11a is the same as the inner peripheral surface Ba curvature radius R of the cylinder bore B, or the tip of the convex portion 11a is a plane. is there. When the fine concave portion P is formed by using the foam roller 11 having such a convex portion 11a, the bottom portion of the fine concave portion P rises due to the influence of the spring back of the material by plastic working as shown in FIG. 6 (b). When the depth of the central portion is smaller than the peripheral portion and the depth of the fine recess P is thus uneven, it becomes difficult to sufficiently reduce the sliding resistance of the inner peripheral surface Ba of the cylinder bore B. .

  Therefore, by forming the convex portion 11a of the foam roller 11 into a shape that allows for the amount of spring back of the material of the workpiece, as shown in FIG. Can be formed, and the sliding resistance of the inner peripheral surface Ba of the cylinder bore B can be sufficiently reduced.

  As described above, according to the fine recess processing apparatus 1 and the processing method described in the above embodiment, the fine recess P is regularly formed over a wide range in the direction along the axis of the inner peripheral surface Ba of the cylinder bore B and in the circumferential direction. In addition to being able to form accurately and efficiently by arrangement, it is possible to eliminate the influence of the material of the workpiece (cylinder block CB) due to the springback, and to form the fine recesses P having a prescribed shape with high accuracy. Thus, it is possible to provide a sliding member, that is, a cylinder block CB, in which the sliding resistance of the inner peripheral surface (sliding surface) Ba of the cylinder bore B is sufficiently reduced.

  Further, according to the fine recess processing apparatus 1 and the processing method described above, in comparison with the conventional processing using a foam roller that rotates around a rotation axis parallel to the axis of the inner peripheral surface of the cylinder bore, By adopting the foam roller 11 that rotates around the rotation axis 14 orthogonal to the axis of the circumferential surface Ba, the circumferential displacement of the fine recesses P in the arrangement along the axis of the inner circumferential surface Ba is eliminated. In addition to preventing, when the number of fine concave portions P in the circumferential direction is small, the fine concave portions P can be regularly formed over the entire inner peripheral surface Ba in a shorter time than conventional processing.

  Furthermore, according to the fine recess processing apparatus 1 and the processing method described above, it is very easy to manufacture the foam roller 11 as compared with the conventional processing. That is, in the case of forming the rectangular fine concave portion P shown in FIG. 7, in the conventional foam roller that rolls around the axis of the inner peripheral surface, the convex portions are formed at predetermined intervals on the outer peripheral portion as shown in part in FIG. 11 a, and each convex portion 11 a has a long side along the circumferential direction of the foam roller 11.

  In such a conventional foam roller, each convex portion 11a has a shape that allows for a springback amount of the material of the workpiece, that is, the long side of the convex portion 11a has a curvature radius different from the curvature radius of the foam roller 11, and the tip surface Is curved, and if necessary, the corners of the tip surface and the side surface are also curved into a curved surface having a predetermined radius of curvature, the convex portions 11a are oriented in the circumferential direction as described above. Therefore, it is necessary to individually process the curved surface with respect to a large number of convex portions 11a, and it takes a lot of labor and time to produce the foam roller.

  On the other hand, since the foam roller 11 described in the above embodiment rolls in a direction along the axis of the inner peripheral surface Ba, the direction of the convex portion 11a differs from the conventional one by 90 degrees, and the long side is The direction is along the width direction of the foam roller 11. For this reason, even if each convex part 11a has a curved surface as described above, each curved surface can be regarded as being continuous in the circumferential direction, and therefore, simultaneously or continuously with respect to the plurality of convex parts 11a. Therefore, it is possible to easily perform the curved surface processing, saving labor and time as compared with the conventional one.

  Moreover, when the said fine recessed part processing apparatus 1 forms the fine recessed part P in inner peripheral surface Ba of the cylinder bore B, specification of internal peripheral surface Ba is changed by changing the load by a load provision means (compression coil spring 18). It is also possible to intentionally change the depth of the fine recess P in the range.

  Further, the fine recess processing apparatus 1 moves (rolls) the foam roller 11 in the direction along the axis of the inner peripheral surface Ba while rotating the tool holder 10 around the axis of the inner peripheral surface Ba. As shown in FIG. 8, while forming the micro recessed part P along the spiral around the axis line of the inner peripheral surface Ba, it is possible to form a plurality of strips in the circumferential direction. Furthermore, together with the spindle head 2, the tool holder 10 By continuously moving up and down, it is possible to form the fine recesses P along the zigzag spiral.

  As described above, when the fine recesses P are formed along the spiral around the axis of the inner peripheral surface Ba, the arrangement of the fine recesses P along the axis is shifted in the circumferential direction. This is not an irregular shift, which has been a problem in the past, but a uniform shift, and the fine recesses P are formed in a regular arrangement, which can contribute to a reduction in sliding resistance. .

  FIG. 9 is a view for explaining another embodiment of the fine recess processing apparatus of the present invention. The illustrated fine recess processing apparatus 31 is obtained by directly fixing an arm 12 that is a roller support member for supporting the foam roller 11 to the body portion 10A of the tool holder 10, and is a horizontally movable table (see FIG. 2). By this operation, the pressing force of the foam roller 11 against the inner peripheral surface Ba of the cylinder bore B can be adjusted.

  In the fine recess processing apparatus 31 described above, the structure of the apparatus can be simplified by omitting the configuration of the housing in the tool holder 10 and a compression coil spring that is a load applying means. Can be greatly reduced.

  FIG. 10 is a view for explaining still another embodiment of the fine recess processing apparatus of the present invention. In each of the previous embodiments, the inner circumferential surface Ba of the cylinder bore B in the cylinder block CB is exemplified as the circumferential workpiece surface which is a circular hole in the workpiece. The processing device 41 exemplifies the outer peripheral surface Ca of the cylindrical portion C in the shaft ST as a circumferential processed surface that is an outer peripheral surface of the cylindrical portion in the workpiece.

  The illustrated fine recess processing apparatus 41 includes a spindle base 44 provided with a spindle 42 and a chucking device 43 that are rotationally driven, a tailstock 46 provided with a center 45 on the same axis as the spindle 42, and a headstock 44. And a slide 47 for moving the tailstock 46 forward and backward, gripping one end of the shaft ST with the chucking device 43, and supporting the multi-end portion of the shaft ST with the center 45 so that the shaft ST can rotate freely. To rotate.

  Further, the fine recess processing apparatus 41 includes, on the tool holder 50, an arm 12 as a roller support member that rotatably supports the foam roller 11 via the rotating shaft 14, a radial movement means 48 that holds the arm 12, An axial direction moving means 49 that holds the radial direction moving means 48 together with the arm 12 is provided.

  The radial direction moving means 48 moves at least one of the workpiece (shaft ST) and the tool holder 50 in the radial direction of the circumferential workpiece surface (the outer circumferential surface Ca of the cylindrical portion C), and thereby the convex portion of the foam roller 11. Is pressed against the circumferential workpiece surface (the outer circumferential surface Ca of the cylindrical portion C), and in this embodiment, the tool holder 50 is moved.

  The axial direction moving means 49 moves at least one of the workpiece (shaft ST) and the tool holder 50 in a direction along the axis of the circumferential workpiece surface (the outer circumferential surface Ca of the cylindrical portion C). In this embodiment, the tool holder 50 is moved.

  Further, in this embodiment, the main shaft 42 rotates at least one of the workpiece (shaft ST) and the tool holder 50 around the axis of the circumferential workpiece surface (the outer circumferential surface Ca of the cylindrical portion C). Here, the workpiece (shaft ST) is rotationally driven.

  In the fine recess processing apparatus 41, the foam roller 11 is pressed against the outer peripheral surface Ca of the cylindrical portion C of the shaft ST by the radial direction moving means 48, and the tool holder 50 is moved by the axial direction moving means 49 to the axis of the outer peripheral surface Ca. , The foam roller 11 is rolled to continuously form the fine recesses P on the outer peripheral surface Ca.

  In addition, the fine recess processing device 41 is configured to rotate the shaft ST intermittently or continuously by the main shaft 42 during the formation of the fine recess P, so that the outer peripheral surface Ca extends over a wide range. The fine concave portions P are efficiently formed regularly in the axial direction and the circumferential direction of Ca (see FIG. 7), or the fine concave portions P are efficiently formed regularly along the spiral and the circumferential direction around the outer peripheral surface Ca axis. Can be formed (see FIG. 8).

  In addition to the cylinder block CB and the shaft ST mentioned in the above-described embodiments, the fine recess processing apparatus and the processing method of the present invention, specifically, shafts such as a crankshaft and a camshaft constituting an automobile engine, a piston It can be applied to various sliding members having sliding surfaces such as piston pins, and the fine concave portions P having a uniform depth are regularly and efficiently formed on the circumferential sliding surfaces of these sliding members. An excellent sliding member that can be formed well and has low sliding resistance can be provided.

  In addition, the shape of the convex portion that allows for the amount of spring back of the fine concave portion or material is not limited to the above embodiment, and it is also possible to change the shape of the fine concave portion according to the desired sliding resistance. In addition, as for the convex portion, in addition to a curved end surface as in the embodiment, an appropriate shape such as a spherical surface, a pointed shape or a weight shape formed from a plurality of planes can be selected.

It is sectional drawing explaining one Example of the fine recessed part processing apparatus of this invention. It is a perspective view explaining the whole fine recessed part processing apparatus. It is the front view (a) explaining a foam roller, a side view (b), and sectional drawing (c) of an outer peripheral part. It is a side view explaining a part of conventional foam roller. It is sectional drawing (a) at the time of fine recessed part formation explaining the convex part shape of the foam roller of this invention, and sectional drawing (b) after fine recessed part formation. It is sectional drawing (a) at the time of fine recessed part formation explaining the convex part shape of the foam roller as a comparative example, and sectional drawing (b) after fine recessed part formation. It is a fragmentary top view of the internal peripheral surface explaining the arrangement | sequence of the formed fine recessed part. It is a fragmentary top view of the internal peripheral surface explaining the other arrangement | sequence of the formed fine recessed part. It is sectional drawing explaining the other Example of the fine recessed part processing apparatus of this invention. It is a side view explaining the further another Example of the fine recessed part processing apparatus of this invention.

Explanation of symbols

B Cylinder bore (circular hole)
Ba Inner peripheral surface (circumferential processed surface)
CB Cylinder block (workpiece)
C Cylindrical part Ca Outer peripheral surface (circumferential processed surface)
P Fine recess ST Shaft (workpiece)
1 31 42 Micro-concave processing device 2 Spindle head (Axial direction moving means)
3 42 Spindle (Rotation drive means)
4 Table (radial movement means)
10 50 Tool holder 11 Foam roller 11a Convex part 12 Arm (roller support member)
14 Rotating shaft 18 Compression coil spring (loading means)

Claims (7)

An apparatus for forming a large number of minute recesses on a circumferential workpiece surface that is an outer circumferential surface of a cylindrical portion or an inner circumferential surface of a circular hole in a workpiece,
A foam roller having a convex part for forming a fine concave part on the outer peripheral part;
A roller support member that rotatably supports the foam roller by a rotation axis orthogonal to the axis of the circumferential workpiece surface;
A tool holder for holding a roller support member;
A load applying means for applying a load to the roller support member to press the convex portion of the foam roller against the circumferential workpiece surface;
An axial direction moving means for moving at least one of the workpiece and the tool holder in a direction along the axis of the circumferential workpiece surface;
A fine recess processing apparatus, wherein the convex portion of the foam roller has a shape that allows for a springback amount of the material of the workpiece. An apparatus for forming a large number of minute recesses on a circumferential workpiece surface that is an outer circumferential surface of a cylindrical portion or an inner circumferential surface of a circular hole in a workpiece,
A foam roller having a convex part for forming a fine concave part on the outer peripheral part;
A roller support member that rotatably supports the foam roller by a rotation axis orthogonal to the axis of the circumferential workpiece surface;
A tool holder for holding a roller support member;
Radial moving means for moving at least one of the workpiece and the tool holder in the radial direction of the circumferential workpiece surface and pressing the convex portion of the foam roller against the circumferential workpiece surface;
An axial direction moving means for moving at least one of the workpiece and the tool holder in a direction along the axis of the circumferential workpiece surface;
A fine recess processing apparatus, wherein the convex portion of the foam roller has a shape that allows for a springback amount of the material of the workpiece. The fine recess processing apparatus according to claim 1, further comprising a rotation driving unit configured to rotate at least one of the workpiece and the tool holder about an axis of a circumferential workpiece surface. When forming a micro recessed part in the circumferential processed surface of a workpiece using the micro recessed part processing apparatus of Claim 3, a foam roller is press-contacted to the circumferential processed surface, and a workpiece and a tool holder By moving at least one of these in a direction along the axis of the circumferential workpiece surface and rolling the foam roller, it is possible to continuously form fine recesses in the direction along the axis of the circumferential workpiece surface. A method for processing a fine concave portion. When forming a micro recessed part in the circumferential processed surface of a workpiece using the micro recessed part processing apparatus of Claim 3, a foam roller is press-contacted to the circumferential processed surface, and a workpiece and a tool holder Rotating the foam roller by moving at least one of the workpiece and the tool holder in a direction along the axis of the circumferential workpiece surface while rotating at least one of the workpieces around the axis of the circumferential workpiece surface Thus, the fine recess processing method is characterized in that the fine recess is continuously formed along the spiral around the axis of the circumferential workpiece surface. After the continuous formation of the fine recesses in the axial direction of the circumferential work surface is completed, at least one of the work piece and the tool holder is rotated by a predetermined angle, and then the fineness in the axial direction of the circumferential work surface is performed. 6. The method for forming fine recesses according to claim 4, wherein continuous formation of recesses and rotation of a predetermined angle of at least one of the workpiece and the tool holder are alternately repeated. A sliding member having a circumferential sliding surface which is an outer peripheral surface of a cylindrical portion or an inner peripheral surface of a circular hole, wherein the circumferential shape is obtained by the fine recess processing method according to any one of claims 4 to 6. A sliding member characterized in that a large number of fine recesses are formed on a circumferential sliding surface which is a surface to be processed.

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