indentation-forming polishing tool

Abstract

Indentation-forming polishing tool (1), comprising: a mandrel (30) which is attached to a processing machine for rotation on a rear side belonging to it; and a cylindrical frame (40) rotatably mounted externally on a tip side of the mandrel (30), the frame holding a roller element (41) and a pressure element (42), the roller element (41) and the pressure element (42) being driven by rotation of the mandrel (30) to form depressions by the pressure element (42) and depressions by the roller element (41) in an inner surface of a workpiece (W) by rotation of the mandrel (30) with the frame (40) arranged within the inner surface of the workpiece (W), wherein the mandrel (30) has a recess adjustment mechanism, the recess adjustment mechanism comprising: a rotating section for the rolling element (41) which causes the rolling element to rotate without moving radially in and out of the frame (40); and a rotary section for rotating the pressure element (42) in and out, which causes the pressure element (42) to rotate while moving radially in and out of the frame (40).

Description

BACKGROUND 1. Technical field

[0001] The present invention relates to a polishing tool, and more precisely to a polishing tool forming depressions or recesses. 2. Related Technology

[0002] In general, for sliding elements (glides) used under stringent conditions involving high rotational speed and heat, such as fluid dynamic bearing surfaces in motors or hard disk drives, a technology is known in which microgrooves or depressions are formed in a sliding surface to improve lubrication performance and reduce the frictional resistance of the sliding surface. Examples of known technologies for forming depressions in a sliding surface include WPC treatment (fine particle shot blasting), laser beam processing, vibratory finishing, etc.

[0003] On the other hand, polishing is categorized as plastic deformation, in which a workpiece surface is pressed in or broken down and deformed by rotating a hard roller while it is pressed against the workpiece to increase surface hardness and roughness. Polishing can significantly improve the durability, wear resistance, and reliability of the sliding surface.

[0004] A known tool for polishing and forming depressions in a workpiece surface is disclosed, for example, in JP 2007-301645A. The depression-forming tool disclosed in JP 2007-301645A comprises a mandrel mounted for rotation on a processing machine and a retainer (a frame) rotatably mounted externally on the mandrel. The retainer holds several rollers (rolling elements) and several balls (pressing elements) in such a way that the rollers and balls can move radially in and out of the outer surface of the retainer. Furthermore, as the mandrel rotates, projections formed in an outer surface of the mandrel engage with the rollers and balls, causing the rollers and balls to roll while vibrating against the inner surface of the workpiece. In this way, depressions are formed in the inner surface of the workpiece.

[0005] However, according to JP 2007-301645A, a problem still exists in that setting a recess shape (such as a groove width, groove length, or groove depth) is difficult due to the polygonal cross-sectional shape of the mandrel. Rotation of the mandrel causes both the rollers and the balls to move radially into and out of the outer surface of the retainer simultaneously. In particular, an error in precisely positioning the tool on the inner surface of the workpiece causes a change in the distance the rollers and balls move radially in and out at the beginning of recess formation. Thus, stable forming or shaping is impossible, making it more difficult to set the recess shape.Furthermore, according to JP 2007 - 301 645 A, there is still a problem in that the depressions are formed redundantly in a tool retraction operation (or at the time when the tool is retracted) because the tool diameter is not reduced at the time the tool is retracted after the inner surface of the workpiece has been machined.

[0006] DE 22 09 234 A discloses a fine boring and burnishing device and a device for its use on machine tools.

[0007] DE 26 44 292 A1 discloses a combined peeling and burnishing tool.

[0008] DE 33 24 494 C1 discloses a rolling tool for smoothing cylindrical surfaces.

[0009] US 3,934,443 A discloses a shot peening tool comprising a cylindrical body with a plurality of holes, each suitable for receiving a spherical ball bearing. A sleeve element with multiple holes is arranged above the cylindrical body, each hole in the sleeve corresponding to a hole in the cylindrical body. The diameter of the opening in the sleeve is smaller than the diameter of the spherical ball. Inside the cylindrical body is a rotatable driver body containing an even number of individual rotatable hammers designed to sequentially contact the balls. During operation, each hammer can rotate about its own axis, thus providing a new point of contact for the movement of the balls.

[0010] JP 2010-105 112 A discloses a smoothing tool for producing depressions which is capable of producing depressions on an outer circumferential surface of a workpiece without the need for special mechanical equipment. SUMMARY

[0011] Accordingly, the present invention was made in view of the problems and tasks described above, and one objective of the present invention is to provide a polishing tool that does not form depressions and prevents the formation of depressions during the withdrawal of the tool from the workpiece.

[0012] To achieve the objectives described above, according to one aspect of the present invention, a depression-forming polishing tool is provided, comprising: a mandrel attached at its rear end to a processing tool for rotation; and a cylindrical frame rotatably mounted externally to a tip side of the mandrel, holding a roller element and a pressure element for forming depressions in an inner surface of a workpiece by rotating the mandrel, the frame being arranged inside the inner surface of the workpiece, the roller element and the pressure element being driven by rotation of the mandrel. The mandrel includes a depression-setting mechanism. The depression-setting mechanism comprises: a roller element rotating section that causes the roller element to rotate without moving radially in and out of the frame; and a rotating section.Rotary section for rotating in and out or turning in and out of the pressure element, which causes the pressure element to rotate as it moves radially into and out of the frame.

[0013] According to one aspect of the invention, the mandrel includes a recess adjustment mechanism consisting of the rotating roller element section and the rotating section for turning the pressure element in and out. This structure causes the roller element to rotate without moving radially in and out of the frame, thus enabling stable polishing of the inner surface of the workpiece. Furthermore, a desired recess can be formed by causing the pressure element to rotate while moving radially in and out of the frame.In this way, according to the aspect of the present invention, the rolling element can be prevented from moving radially into and out of the frame together with the pressure element, even when the mandrel rotates, thereby allowing easier adjustment of the recess shape (such as groove width, groove length or groove depth) than in the related technology.

[0014] Here, when the balls are used as multiple pressure elements, an advantage is gained that, in cases where holes or grooves, such as connecting rod oil holes or cut holes, are formed in a direction intersecting the inner surface of the workpiece, the balls strike or press against edge sections around the oil holes or the like, thereby simultaneously allowing the removal of burrs on the edge sections of the oil holes or the like. Furthermore, when the rollers are used as multiple pressure elements, an advantage is also gained in that the pressure area can be increased during roller machining, so that a machined surface with excellent surface roughness can be obtained.

[0015] Furthermore, the structure described above preferably includes the following: The roller element contains several rollers, and the pressure element contains several balls. The multiple rollers and balls are spaced alternately around the same circumference of the frame. Each roller is arranged with its axis parallel to an axis of the frame. The rollers have a length greater than the diameter of each ball. The mandrel has a tapered section on a tip end belonging to it, the diameter of which gradually decreases towards the tip of the mandrel. The tapered section has a first region and a second region on an outer surface belonging to it. The first region serves as the rotating section for turning the pressure element in and out. The second region is arranged on both sides of the first region in an axial direction of the mandrel and serves as the rotating section for the roller element.The first section has several flat segments spaced circumferentially. The first section has a polygonal cross-section, while the second section has a circular cross-section. The flat segments have a length greater than the diameter of each sphere and less than the length of each roller. When the frame is attached to the mandrel, the rollers are brought into contact with the second section without touching the flat segments of the first section, while the spheres are only brought into contact with the first section.

[0016] The first section, which serves as the rotating section for inserting and removing the pressure element of the present invention, has several flat sections and a polygonal cross-section. When the rollers are brought into contact with the first section by rotating the mandrel, they project radially from the frame when they come into contact with the sections between the flat sections of the first section (i.e., the sections corresponding to the angles of the polygonal cross-section). Conversely, the rollers are retracted radially from the frame when they come into contact with the flat sections (i.e., the sections corresponding to the sides of the polygonal cross-section). However, in this configuration, the rollers are brought into contact with the second section, which serves as the rotating section for the roller element, without touching the flat sections of the first section.The second area also has a tapered shape without any rough areas on its surface. As the mandrel rotates, the rollers can be turned without being affected by the flat sections formed in the first area. In other words, the rollers of the present invention are brought into contact with the second area without touching the flat sections of the first area. Thus, the rollers can rotate with the rotation of the mandrel without retracting radially, even though the first area contains the flat sections. On the other hand, the balls of the present invention are only brought into contact with the first area. Therefore, the balls move radially in and out as they rotate with the mandrel.

[0017] This structure prevents the rollers from moving radially in and out during the cavity formation process, thus simplifying the adjustment of the cavity shape. Furthermore, the rollers and balls can be arranged on the same circumference, allowing for a further reduction in tool size compared to a case where the rollers and balls are arranged separately on the frame.

[0018] The structure described above preferably also includes the following: The roller element contains several rollers, and the pressure element contains several special rollers. The multiple rollers and special rollers are arranged alternately on the same circumference of the frame. Each roller and each special roller is arranged with its respective axis parallel to an axis of the frame. Each of the special rollers has a ring that rotates about an associated axis and a pin that holds the ring. The ring has an outer surface with a pointed shape. The rollers have a length greater than the thickness of the ring. The mandrel has a tapered section at an associated point, which gradually decreases in diameter towards a point of the mandrel. The tapered section has a first region and a second region on an associated outer surface.The first section serves as the rotary section for inserting and removing the pressure element. The second section is arranged on both sides of the first section in an axial direction along the mandrel and serves as the rolling element of the rotary section. The first section has a plurality of circumferentially spaced flat sections. The first section has a polygonal cross-section, while the second section has a circular cross-section. The flat sections have a length greater than the thickness of the ring and less than the length of each roller. When the frame is attached to the mandrel, the rollers are brought into contact with the second section without touching the flat sections of the first section, while the ring is only brought into contact with the first section.

[0019] The first section, which serves as the rotating section for inserting and removing the pressure element, has several flat sections and a polygonal cross-section. When the rollers are brought into contact only with the first section by the rotation of the mandrel, they are radially extended from the frame if they come into contact with sections between the flat sections of the first section (i.e., with sections corresponding to the angles of the polygonal cross-section). Conversely, the rollers are radially retracted from the frame if they come into contact with the flat sections (i.e., with sections corresponding to the sides of the polygonal section). However, in this configuration, the rollers are brought into contact with the second section, which serves as the rotating section for the roller element, without touching the flat sections of the first section.The second area also has a tapered shape without any rough areas on its surface. As the mandrel rotates, the rollers can rotate without being affected by the flat sections formed in the first area. In other words, the rollers of the present invention are brought into contact with the flat sections of the first area. Thus, the rollers can rotate with the mandrel without being drawn in radially, even though the first area contains the flat sections. On the other hand, the rings of the present invention are only brought into contact with the first area. Therefore, the rings move in and out as they rotate with the mandrel.

[0020] This structure prevents the rollers from moving radially in and out of the cavity during cavity formation, thus allowing for easy adjustment of the cavity shape. Furthermore, the rollers and rings can be positioned on the same circumference, enabling a further reduction in tool size compared to a case where the rollers and rings are arranged separately and axially relative to the frame. Additionally, in this structure, the ring serves as the pressure element. The ring rotates around the axis and has a tapered outer surface, allowing for a further reduction in cavity width compared to a case where a ball is used as the pressure element.

[0021] Additionally, the structure described above can include a tool diameter adjustment mechanism for setting a tool diameter that is the diameter of a first enclosing circle connecting the edge regions of the multiple rollers. This structure is advantageous because the processing dimension of the workpiece's inner surface can be adjusted. Furthermore, the tool diameter adjustment mechanism preferably includes a mechanism in which, at the moment the depression-forming polishing tool is retracted from the workpiece's inner surface, the polishing tool encounters resistance from the workpiece's inner surface, thereby moving the frame and mandrel relatively in the axial direction to automatically reduce the tool diameter.This is done because it makes it possible to prevent redundant depressions from being formed when the depression-forming polishing tool is withdrawn from the inner surface of the workpiece.

[0022] The structure described above preferably also includes the following: The rolling element contains several rollers. The multiple rollers are spaced apart from each other on a first circumference of the frame. Each roller is arranged with its axis parallel to an axis of the frame. The pressure element contains several balls. The multiple balls are spaced apart from each other on a second circumference of the frame. The second circumference is spaced axially from the first circumference of the frame. The mandrel has a progressively decreasing diameter towards its tip. The mandrel has a tapered section, which serves as the pivot section for the rolling element, and a stepped shaft section, or shaft section, which is deeper than the tapered section. The stepped shaft section is provided with a retainer on its outer surface.The retainer holds several rotators, which are driven by the rotation of the mandrel, and serves as the rotating section for inserting and removing the pressure element. The retainer holds the multiple rotators so that they are spaced apart from each other on the same circumference of the retainer, with each rotator partially protruding through an outer surface of the retainer. When the frame is attached to the mandrel, the rollers are brought into contact with the tapered section, while the balls are brought into contact with the retainer that holds the multiple rotators.

[0023] With this structure, the rollers rotate with the rotation of the mandrel, while being prevented from moving radially in and out because the tapered section, which serves as the rotating section for the roller element, is in contact with the rollers. Conversely, the retainer, which serves as the rotating section for the insertion and removal of the pressure element, holds the multiple rotators, and the balls are brought into contact with the retainer. Thus, as the retainer rotates, the balls are pushed radially out of the frame to bring them into contact with the rotators held by the retainer. Conversely, when the balls are brought into contact with the sections between the rotators held by the retainer, they are retracted radially out of the frame.

[0024] In this way, this structure, with its integrated balls, prevents the radial inward and outward movement of the rollers within the recess, thus simplifying the adjustment of the recess shape. The roller and ball are also spaced apart axially within the frame (in a longitudinally offset manner). This allows the roller to be brought into contact with the groove, even if there is a groove in the inner surface of the workpiece. This also provides the advantage of maintaining the frame's axial movement, thereby stabilizing the recess formation.

[0025] In addition, the structure described above preferably further includes an adjustment mechanism for the tool diameter and an adjustment mechanism for the overhang. The tool diameter adjustment mechanism sets a tool diameter that is the diameter of a first enclosing circle connecting the edge regions of the plurality of rollers. The overhang adjustment mechanism sets an overhang that is the value of a second enclosing circle connecting the edge regions of the plurality of spheres and projecting radially from the frame beyond the first enclosing circle. The overhang adjustment mechanism is preferably configured to change the overhang to a different value without changing the tool diameter.

[0026] This structure is equipped with a tool diameter adjustment mechanism, allowing the tool diameter to be set to a desired value. The overhang adjustment mechanism also sets the overhang to a different value without changing the tool diameter, thus allowing for varying countersink depths. In other words, this structure can create countersinks of different depths, even if the inner surface of the workpiece has the same finished diameter. This allows for the creation of an optimal countersink shape to meet specific application requirements.Additionally, the tool diameter adjustment mechanism preferably includes a mechanism whereby, at the moment the depression-forming polishing tool is withdrawn from the inner surface of the workpiece, the polishing tool absorbs the resistance from the inner surface of the workpiece, thereby moving the frame and mandrel relatively in the axial direction to automatically reduce the tool diameter. This is because it prevents redundant depressions from being formed at the moment the depression-forming polishing tool is withdrawn from the inner surface of the workpiece.

[0027] It should be noted that the overhang described herein refers to the diameter of the second enclosing circle, which connects the edge regions of the multiple spheres and projects radially from the frame beyond the first enclosing circle, which connects the edge regions of the multiple rollers. Thus, the overhang is obviously determined by (diameter of the second enclosing circle - diameter of the first enclosing circle) / 2.

[0028] Furthermore, in the structure described above, the tool diameter adjustment mechanism is preferably designed such that it simultaneously moves the multiple rollers and balls radially of the frame and adjusts the tool diameter without changing the amount of overhang.

[0029] With this structure, in which the overhang amount remains unchanged at the time the tool diameter is set, the diameter of the second enclosing circle decreases as the tool diameter decreases, while the diameter of the second enclosing circle increases as the tool diameter increases. Consequently, the diameter of the second enclosing circle also decreases in a case where, for example, the inner surface of the workpiece is machined with the depression-forming polishing tool of the present invention, when the tool diameter is reduced by the tool diameter setting mechanism at the time the polishing tool is returned to its initial position. Therefore, redundant depression formation in the inner surface of the workpiece during the polishing tool return process is avoided.

[0030] In addition, the structure described above preferably includes the following: The overhang adjustment mechanism is externally attached to the stepped shaft section and has several adjustable rings. These rings set the axial position of the retainer to a predetermined position. The rotators have an outer surface with a tapered shape, the diameter of which gradually decreases towards their tip. The diameter of a third enclosing circle, connecting the outer edges of the rotators, changes according to the axial position of the retainer. The overhang is also adjusted by changing the axial position of the retainer.

[0031] With this structure, the protrusion of the balls can be easily adjusted by rearranging the adjustable rings and setting the axial position of the retainer to a predetermined position. More precisely, according to this structure, the diameter of the third enclosing circle is changed at a position in the axial direction (for example, at a position corresponding to the intersection of a perpendicular line drawn from the center of a ball towards the central axis of the retainer with the central axis of the retainer) by changing the axial position of the retainer. Changing the diameter of the third enclosing circle changes the engagement position between the ball and the rotator in the radial direction.This means that the engagement position between the ball and the rotator moves outwards in the radial direction (in other words, the radially projecting amount of the ball increases) with the increasing diameter of the third enclosing circle. Consequently, the amount of the ball's projection can be adjusted by setting the axial position of the retainer.

[0032] The balls are also moved radially in and out by the engagement of the rotators, thus allowing a reduction in the distance over which the pressure element is pressed, compared to the structure according to the related technology, in which protrusions of the mandrel with polygonal cross-section cause the pressure element to move radially in and out. Thus, the recess length can also be reduced.

[0033] Additionally, the tapered section and the rotators preferably have the same tapering angle or skew angle.

[0034] With this structure, the diameter of the first enclosing circle connecting the edge regions of the multiple rollers and the diameter of the multiple spheres increase or decrease by the same value when the tool diameter adjustment mechanism adjusts the tool diameter, because the taper angles are equal.

[0035] According to the present invention, a recess adjustment mechanism is provided which allows the single pressure element to move radially in and out of the frame, while preventing the roller element from moving radially in and out of the frame. Thus, the recess shape can be easily adjusted. BRIEF DESCRIPTION OF THE FIGURES

[0036] Embodiments of the present invention will be described in detail based on the following drawings, wherein: Fig. 1 in a partial sectional view shows the general structure of a polishing tool forming depressions according to a first embodiment of the present invention; Fig. 2 a sectional view along the line AA from Fig. 1 is, where the in Fig. 1 The polishing tool shown is arranged within an inner surface of a workpiece, forming depressions; Fig. 3 an enlarged sectional view of the essential parts along line BB from Fig. 1 is; Fig. 4 in a partial sectional view shows the general structure of a polishing tool forming depressions according to a second embodiment of the present invention; Fig. 5 a section view along the line C-CV from Fig. 4 is, where the in Fig. The polishing tool shown in the 4 depressions is arranged within an inner surface of the workpiece; Fig. 6 a detailed view of one in Fig. 4 shows a special role; Fig. 7A or 7B the shape of the one in Fig. 4 depressions formed by a polishing tool or the shape of depressions formed by a polishing tool according to the related technology shown; Fig. 8 is a general front view of a polishing tool forming depressions according to a third embodiment of the present invention; Fig. 9 in a partial section view the general structure of the in Fig. The polishing tool shown in the 8 depressions forms the depressions; Fig. 10 a cross-sectional view along the line DD from Fig. 8 is, where the in Fig. The polishing tool, which forms 8 depressions, is arranged within the inner surface of the workpiece; Fig. 11 a cross-sectional view along the line EE from Fig. 8 is, where the in Fig. The polishing tool, which forms 8 depressions, is arranged within the inner surface of the workpiece; Fig. 12A or 12B the shape of the one in Fig. 8 shown depressions formed by a polishing tool or the shape of depressions formed by a polishing tool forming depressions according to the related technology; Fig. 13 a general front view of a depression-forming polishing tool according to a first modification; and Fig. 14 is a general front view of a depression-forming polishing tool according to a second modification. DETAILED DESCRIPTION

[0037] In the following, a depression-forming polishing tool according to embodiments of the present invention will be described in detail, possibly with reference to the accompanying drawings. For convenience, the depression-forming polishing tool will be referred to simply as a "polishing tool". First, a polishing tool according to a first embodiment of the present invention will be described with reference to Fig. 1 to 3 are described. As in Fig. As shown in Figure 1, the polishing tool according to the first embodiment is composed of the following: a mandrel 30 attached to a processing machine (not shown) such as a lathe or turning machine for rotation; a frame 40 attached to the outside of the mandrel 30; and a tool diameter setting mechanism 10 for setting a tool diameter.

[0038] As in Fig. As shown in Figure 1, the mandrel 30 is generally designed in a round-bar shape. The mandrel 30 has: at a rear end belonging to it, a shaft or leg 32, which is attached to a processing machine (not shown) such as a lathe; at a tip end belonging to it, a tapered section 33; and in a substantially central or middle section belonging to it, a main body 31. The tapered section 33 has a tapered or chamfered shape, the diameter of which decreases towards an end belonging to it (the left side in Figure 1). Fig. 1) decreases gradually. The tapered section 33 contains a first region 33a, which is formed in a substantially central section belonging to it, and a second region 33b, which is formed in the anterior and posterior part (i.e., left and right in Fig. 1) of the first area 33a in the axial direction of the mandrel 30.

[0039] The second region 33b is circular in cross-section and shaped like a circularly truncated cone. The outer surface of the second region 33b has no rough areas. On the other hand, the outer surface of the first region 33a is formed with several flat sections 36, each having a flat surface and slightly recessed or offset in a corresponding outer surface. More precisely, the sixteen flat sections 36 are spaced close together in the circumferential direction of the mandrel 30. Thus, the sections of the outer surface of the first region 33a corresponding to the flat sections 36 are slightly recessed or offset. The sections between the flat sections 36 also correspond to the projections or protrusions 35 that extend slightly through the flat sections 36. Consequently, the cross-section of the first region 33a, as shown in Fig. Figure 2 shows a polygonal shape (namely, an almost right-angled hexadecagon) with projections 35 as angles and flat sections 36 as sides. It should be noted that a surface with a slight curvature is formed between the flat sections 36 and the projections 35 to allow a ball 42 to roll smoothly or without friction.

[0040] As will be described in more detail later, it should be noted that when the frame 40 is attached externally to the mandrel 30, a roller (rolling element) 41 is arranged such that it extends over the first region 33a and the second regions 33b, bringing the roller 41 into contact with the second regions 33b without touching the flat section 36. Conversely, the ball (pressure element) 42 is brought into contact only with the first region 33a. Note also that the shaft 32 can have various shapes, including a chamfered or tapered shape, in addition to a straight shape as shown in this embodiment, for attachment to a processing machine.

[0041] Next, the frame 40 is cylindrical in shape. The frame 40 rotatably holds the multiple rollers 41 and also rotatably holds the multiple balls 42 in such a way that the balls 42 can move radially into and out of the surface of the frame 40. More precisely, the eight rollers 41 and the eight balls 42 are alternately spaced around the same circumference of the frame 40. It should be noted that the rollers 41 are attached to the frame 40 with their axes parallel to an axis of the frame 40.

[0042] Note that: the length L1 of the roller 41 is greater than the diameter D1 of the sphere 42; the length L2 of the flat section 36 is greater than the diameter D1 of the sphere 42; and the length L1 of the roller 41 is greater than the length L2 of the flat section 36. Thus, the relationship D1 < L2 < L1 is established. Therefore, as in Fig. As shown in Figure 3, both ends of the roller 41 are brought into contact with the second areas 33b, so that a slight gap CL is created between the essentially central or middle section of the roller 41 and the flat section 36. In other words, both end sections of the roller 41 are supported by the second areas 33b in such a way that the central section of the roller 41 is prevented from contacting the surface of the flat section 36.

[0043] It should be noted that the length L1 of the roller 41 is always such that it spans the flat section 36 even when the relative positions in the axial direction of the mandrel 30 and the frame 40 are adjusted by the tool diameter adjustment mechanism 10 (described in detail later). That is, even when the tool diameter adjustment mechanism 10 is operated, the roller 41 is always prevented from contacting the surface of the flat section 36. Furthermore, the roller 41 has a tapered shape, with its diameter decreasing gradually from one end (the left end) to the other. Fig. 3) towards the other end (the right end in Fig. 3) slightly reduced. That is, the roller 41 has a diameter D2 at its left end that is slightly larger than the diameter D3 at its right end. Regarding the direction in which the roller 41 is attached to the frame 40, one end (the end with the larger diameter) of the roller 41 corresponds to the tip side of the polishing tool 1, and the other end (the end with the smaller diameter) corresponds to the rear side, or side at the back end, of the polishing tool 1.

[0044] As in Fig. As shown in Figure 2, the rollers 41 and the balls 42 are positioned between the outer surface of the tapered section 33 of the mandrel 30 and the inner surface of the workpiece W when the polishing tool 1 is inserted into the workpiece W. It should be noted that a special steel alloy is used because the rollers 41, the balls 42, and the frame 40 must possess high resistance. This special steel alloy undergoes heat treatment to improve its hardness and tensile strength. Depending on the operating conditions, surface coating processes such as DLC, TIN, or TICN can also be applied, further improving resistance.

[0045] Next, the tool diameter adjustment mechanism 10 is designed to adjust the diameter (the diameter DA in Fig. 2) to set a first enveloping circle that connects the edge regions of the rollers 41. As in Fig. As shown in Figure 1, the interior of the tool diameter adjustment mechanism 10, which is covered by a housing 13, a front cap 14, and a thick adjustable ring 12, is equipped with an adjustable nut 11, a wrench 26, a bearing 25, a spring 21, and the like. The adjustable nut 11 has an internal thread 11a for engaging a helical section or threaded section 31a and is also provided with external teeth 17 around its edge. A stop surface for abutting the bearing 25 is also formed at one front end of the adjustable nut 11. The thick adjustable ring 12 is rotatably and non-removably mounted or supported on the adjustable nut 11 by a snap ring 15. The thick adjustable ring 12 is freely mounted on the main body of the mandrel 30 with a clearance between them and is provided on its edge area with external teeth 18, which are similar to the external teeth 17 of the adjustable nut 11.It should be noted that the thick adjustable ring 12 is prevented by the key 26 from moving circumferentially around the mandrel 30.

[0046] The housing 13 is cylindrical in shape. Inside the housing 13 are internal teeth 19 and 20, which engage with external teeth 17 and 18, respectively. The front cap 14 is also located in front of the housing 13. The spring 21 is positioned between a retaining ring 24, which is attached to the area near the rear end of the frame 40, and an inner surface of the front cap 14. Note that reference numerals 22 and 23 denote spring seats designed to effectively hold the spring 21. Reference numeral 16 also denotes a support ring or pressure ring arranged to allow frictionless sliding between the spring seat 23 and the front cap 14 when the housing 13 rotates.

[0047] To adjust the tool diameter using the tool diameter adjustment mechanism 10 designed in this way, the housing 13 is first grasped and moved backwards against the force of the spring 21. The housing 13 moves while its inner teeth 19 and 20 engage with the outer teeth 17 of the adjustable nut 11 and the outer teeth 18 of the thick adjustable ring 12, respectively. As the housing 13 moves further, the engagement between the inner teeth 20 and the outer teeth 18 is released. In this state, the outer teeth 17 remain engaged with the inner teeth 19 because the inner teeth 19 are designed with a wide width.

[0048] Then the housing 13 is rotated while being pushed backward. The inner teeth 19 and the outer teeth 17 remain engaged. The inner teeth 20, which are disengaged from the engagement with the outer teeth 18, are also free to rotate. Thus, the housing 13 and the adjustable nut 11 rotate together as the housing 13 rotates, so that the adjustable nut 11 moves forward or backward along a helical guide relative to the threaded section 31a of the mandrel 30. At this time, the thick adjustable ring 12 moves along the mandrel 30 with the wrench 26, while the adjustable nut 11 moves longitudinally as it rotates, because the adjustable nut 11 and the thick adjustable ring 12 are rotatably locked by the snap ring 15.

[0049] The longitudinal movement of the adjustable nut 11 is relatively equivalent to the longitudinal movement of the mandrel 30. Thus, this movement causes the contact position between the tapered section 33 of the mandrel 30 and the roller 41 to move towards a tip or a base or rear section of the polishing tool 1. This changes the diameter (the diameter DA in Fig. 2) of the first enclosing circle connecting the edge regions of the rollers 41, according to changes in the diameter of the tapered section 33 to a desired value

[0050] After the rollers 41 have been set to a desired value, the housing 13 is released to cause the previously compressed spring 21 to expand and push the front cap 14 forward. The housing 13 is thus moved forward in one continuous motion and stopped by contact with the thick adjustable ring 12. In this state, the internal teeth 19 and 20 of the housing 13 engage with the external teeth 17 of the adjustable nut 11 and the external teeth 18 of the thick adjustable ring 12, respectively. Rotation of the thick adjustable ring is also prevented by the wrench 26 and a keyway. This prevents the housing 13 from rotating relative to the mandrel 30. The adjustment of the tool diameter is thus completed.

[0051] Next, a process or procedure for forming depressions in the inner surface of the workpiece W using the polishing tool 1 constructed as described above will be described. <einstellvorgang>

[0052] In the setting process, the tool diameter of the rollers 41 is first adjusted. More precisely, the housing 13 is moved to one drive side of the mandrel 30, i.e., the side of the shank 32, to adjust the tool diameter. Because the tool diameter is increased by turning the housing 13 to the right and decreased by turning it to the left, the housing 13 is then rotated to the right or left to set the desired tool diameter. After the housing 13 has been rotated to a position corresponding to the desired tool diameter, releasing the housing 13 causes it to return to its initial position under the restoring force of the spring 21, and the housing 13 is automatically locked against rotation. Thus, the tool diameter is set. The tips of the rollers 41 are then measured with a micrometer to verify that the tool diameter is correctly set. <bearbeitungsvorgang>

[0053] In a machining operation, the shaft 32 is first attached to a processing machine. Then, the polishing tool 1 is moved into a recess-forming position on the inner surface of the workpiece W. It should be noted that the machining length of the workpiece W can be adjusted as desired when using the polishing tool 1 simply by adjusting the stroke control settings of the processing machine.

[0054] Next, the processing machine is driven to begin rotating the mandrel 30. For example, when the mandrel 30 is rotated clockwise from its tip end, each of the rollers 41 rotates counterclockwise (on its axis) along the outer surface of the mandrel 30. At this time, the counterclockwise rotation of the rollers 41 causes them to rotate clockwise around the inner surface of the workpiece W and the outer surface of the tapered section 33 of the mandrel 30.

[0055] As described above, each of the rollers 41 is arranged in contact with the outer surface of the second areas 33b in such a way that it spans the flat section 35, thereby preventing the roller 41 from contacting the flat section 36 of the first area 33a in all rotational positions of the mandrel 30. Although the roller 41 rotates due to the rotation of the mandrel 30, it is consequently prevented from moving radially with respect to the frame 40, thus allowing an operator to stably polish the inner surface of the workpiece W with the rollers 41.

[0056] On the other hand, the movement of the balls 42 by the rotation of the mandrel 30 differs slightly from that of the rollers 41. Like the rollers 41, each ball 42 rotates clockwise with the rotation of the mandrel 30, while rotating counterclockwise on its axis along the outer surface of the tapered section 33 of the mandrel 30. However, as the ball 42 rotates around the mandrel 30, it moves alternately through the flat sections 36 formed on the first area 33a and the projections 35, in a state where it is sandwiched between the inner surface of the workpiece W and the outer surface of the tapered section 33. Thus, the ball 42 rolls along the inner surface of the workpiece W, while radially with respect to the frame 40, it is subjected to differences in height (the clearance CL in the frame). Fig. 3) vibrates between the flat sections 36 and the projections 35. This radial in-and-out movement of the ball 42 forms depressions in the inner surface of the workpiece W.

[0057] It should be noted that the first section 33a, which has the function of causing the balls 42 to rotate as they move radially in and out of the frame, corresponds to a rotary section for rotating a pressure element in and out according to the present invention. Likewise, the second section 33b, which has the function of causing the rollers 41 to rotate as they move radially in and out of the frame, corresponds to a rotary section for a roller element according to the present invention. Additionally, the tapered section 33, which includes the first section 33a and the second section 33b, corresponds to a recess adjustment mechanism of the present invention. <Werkzeugrückzug / entfernungsvorgang>

[0058] During a tool retraction or removal process, the polishing tool 1 is first moved out of the inner surface of the workpiece W. At this time, the spring 21 in the polishing tool 1 is moved into an extended position between the spring 21 and the inner surface of the workpiece W due to its frictional force (resistance), thereby moving the frame 40 forward relative to the mandrel 30. The diameter DA of the first enclosing circle connecting the edge regions of the rollers 41, i.e., the tool diameter, is then automatically reduced. This prevents the formation of redundant depressions during the process of returning the polishing tool 1 to its initial position. The depression formation process then ends when the polishing tool 1 is returned to its initial position and removed from the processing machine.

[0059] In this way, in the polishing tool 1 according to the first embodiment, the rollers 41 are prevented from moving radially with respect to the frame 40, thereby stabilizing the rotational movement of the rollers 41 in the workpiece W. Thus, a correct recess shape is achieved during recess formation to meet the operating conditions by simply adjusting the shape, machining conditions, etc., of the balls 42 as appropriate. As a result, excellent lubricating properties are imparted to the inner surface of the workpiece W.

[0060] In the first embodiment of the polishing tool 1, the shot peening effect can also increase the surface hardness of the inner surface of the workpiece W and exert a residual compressive load on the workpiece surface, thereby improving the fatigue strength of the workpiece surface. Additionally, with the structure in which the balls 42 are used as pressure elements, in a case where, for example, oil holes are formed in a direction intersecting the inner surface of the workpiece W, the balls press against or strike edge sections around the oil holes, thus allowing the removal of burrs on the edge sections of the oil holes at the same time.

[0061] Furthermore, in the polishing tool 1 according to the first embodiment, the balls 42 and the rollers 41 can be arranged on the same circumference, thereby allowing a reduction in the size of the tool 1.

[0062] Next, a polishing tool 101 according to a second embodiment of the present invention is described with reference to Fig. 4 to 7 are described. It should be noted that the same elements as those of the polishing tool 1 according to the preceding first embodiment are designated by the same reference numerals and that their description will not be repeated.

[0063] An important feature of the polishing tool 101 according to the second embodiment is that special rollers 142 are used as pressure elements instead of the balls 42. As in Fig. As shown in Figure 4, the polishing tool 101 is constructed such that the rollers (roller elements) 141 and the special rollers (pressure elements) 142 are arranged alternately on the same circumference of a cylindrical frame 140. More precisely, the eight rollers 141 and the eight special rollers 142, which are arranged alternately at equal intervals, are rotatably held by the frame 140. Furthermore, both the rollers 141 and the special rollers 142 are aligned parallel to an axis of the frame 140. The rollers 141 and the special rollers 142 also have the same length L3.

[0064] As in Fig. As shown in Figure 6, each of the special rollers 142 is constructed from a pair of bolts or pins 142b and a ring 142a, which are arranged coaxially. The ring 142a is mounted in such a way that it can rotate freely about the axis. The ring 142a is provided with a through-hole 142a-2 and has an outer surface with a tapered shape 142a-1. It should be noted that the ring 142a is positioned at a location corresponding to the first region 33a of the mandrel 30 when the frame 140 is attached to the mandrel 30. Thus, the ring 142a engages alternately with the flat sections 36 and the projections 35 as it rotates with the mandrel 30, and thereby moves radially in and out of the frame 140. The radial inward and outward movement of the ring 142a forms depressions in the inner surface of the workpiece W.

[0065] Note that: the thickness T1 of the ring 142a is smaller than the length L3 of the roller 141 and smaller than the length L2 of the flat section 36 formed on the first region 33a of the mandrel 30; and the length L3 of the roller 141 is larger than the length L2 of the flat section 36. Therefore, the relationship T1 < L2 < L3 is established. Thus, although this is not shown in the figure, in the same way as in the first embodiment, both ends of the roller 141 are brought into contact with the second regions 33b of the tapered section 33 of the mandrel 30, so that the small clearance CL (it Fig. 3) between a substantially central section of the roller and the flat section 36. In other words, both ends of the roller 141 are supported by the second sections 33b in such a way that the central section of the roller is prevented from contacting the surface of the flat section 36. Consequently, the roller is prevented from moving radially inwards and outwards with respect to the frame 140, even though the roller 141 is rotated by the rotation of the mandrel 130.

[0066] It should be noted that the length L3 of the roller 141 is always such that it extends over the flat section 36 even when the relative positions in the axial direction of the mandrel 30 and the frame 140 are changed by the tool diameter adjustment mechanism 10. That is, the roller 141 is always prevented from contacting the surface of the flat section 36, even when the tool diameter adjustment mechanism 10 is being operated. Furthermore, the roller 141 has a tapered shape, the diameter of which decreases slightly incrementally from one end (the left end in the Fig. 4) here in the direction of the other end (the right end in Fig. 4) decreases.

[0067] As in Fig. As shown in Figure 5, the rollers 141 and the rings 142a lie between the outer surface of the tapered section 33 of the mandrel 30 and the inner surface of the workpiece W when the polishing tool 101 is inserted into the workpiece W.

[0068] It should be noted that a special steel alloy is used because the mandrel 30, rollers 141, rings 142a, bolts 142b, and frame 140 must exhibit high resistance. This special steel alloy undergoes heat treatment to improve its hardness and tensile strength. Surface coatings such as DLC, TIN, or TICN can also be applied according to the operating conditions, further enhancing durability.

[0069] In the polishing tool 101 constructed in this way, recesses can be formed by the same process as in the polishing tool 1 described above. Fig. 7A represents the shape of the depressions that were actually formed. On the other hand, it represents Fig. 7B shows the shape of the depressions formed by a polishing tool according to the related technology. As can be seen from a comparison between Fig. 7A and Fig. As becomes clear in section 7B, the recess width can be made smaller according to the polishing tool 101 than in the case where the balls are used for recess formation, because the tapered shape 142a-1 of the ring 142a is pressed against the inner surface of the workpiece W to form recesses. In other words, the recess width can be adjusted appropriately simply by using the rings 142a.

[0070] Next, a polishing tool 201 according to a third embodiment of the present invention is described with reference to Fig. 8 to 12 are described. As in Fig. As shown in Figure 8, the polishing tool 201 according to the third embodiment is constructed from: a mandrel 230 mounted for rotation on a processing machine, such as a lathe (not shown); a frame 240 attached to the outside of the mandrel 230; a tool diameter adjustment mechanism 210 for setting a tool diameter; and an overhang adjustment mechanism 203 for setting an overhang amount. The respective structures of the polishing tool 201 are described in detail below with reference to Fig. 9 to 11 will be described.

[0071] As in Fig. As shown in Figure 9, the mandrel 30 is generally formed in a round bar shape. The mandrel 230 has: at its rear end a shaft 232 attached to a processing machine (not shown), such as a lathe; at its tip end a first tapered section 233a, a stepped shaft section 234, and a second tapered section 233b in that order; and in a substantially central section belonging to it a main body 231. The first tapered section 233a and the second tapered section 233b have the same shape, namely a diameter that decreases gradually towards their tip. Their outer surfaces are also smooth, without any rough areas.

[0072] On the other hand, the stepped shaft section 234 has a solid round bar shape with a diameter smaller than those of the first tapered section 233a and the second tapered section 233b, and forms a stepped section that is deeper than the first tapered section 233a and the second tapered section 233b. A threaded section 231a is also formed in an outer surface of the main body 231, and a keyway, which fits a wrench 226, is provided along an axial direction of the main body 231.

[0073] As will be described in more detail later, it should be noted that the first tapered section 233a and the second tapered section 233b are arranged in positions corresponding to rollers (roller elements) 241 when the frame is attached to the mandrel 230 from the outside, while the stepped shaft section 234 is arranged in a position corresponding to balls (pressure elements) 242. Note also that the shaft 232 can have various shapes, including a tapered or chamfered shape in addition to a straight shape as shown in this embodiment, which can be attached to a processing machine.

[0074] The frame 240 has a cylindrical shape. The frame 240 holds the multiple rollers 241 and the multiple balls 242. More precisely, the two rollers 241 and the single ball 242 are arranged in a row spaced apart from each other in the order of roller 241, ball 242, and roller 241, starting from the end face. This row of the two rollers 241 and the single ball 242 is considered as a pair, and twelve pairs are spaced equally around the circumference of the frame. The roller 241 also has a tapered shape, with its diameter gradually decreasing slightly from one end towards the other end. Regarding the direction in which the roller 241 is arranged on the frame 240, one end (the end with the larger diameter) of the roller 241 corresponds to the tip side of the polishing tool 201 and the other end (the end with the smaller diameter) corresponds to the rear side of the polishing tool 201.

[0075] As in Fig. As shown in Figure 10, the balls 242 lie between an outer surface of the retainer 204 (described in detail later), which is attached externally to the stepped shaft section 234 of the mandrel 230, and the inner surface of the workpiece W when the polishing tool 201 is inserted into the workpiece W. Also, as shown in Fig. Figure 11 shows the rollers 241 between the outer surface of the first tapered section 233a of the mandrel 230 and the inner surface of the workpiece W.

[0076] It should be noted that a special steel alloy is used because the mandrel 230, the rollers 241, the balls 242, and the frame 240 must exhibit high resistance. This special steel alloy undergoes heat treatment to improve its hardness and tensile strength. Surface coatings such as DLC, TIN, or TICN can also be applied according to the operating conditions, further enhancing durability.

[0077] Next, the tool diameter adjustment mechanism 210 is designed, which sets the diameter (the diameter DA in Fig. 11) to adjust a first enclosing circle connecting the edge regions of the rollers 241. The tool diameter adjustment mechanism 210 is the same as the tool diameter adjustment mechanism 10 mentioned above. Therefore, the remaining details are omitted.

[0078] The overhang adjustment mechanism 203 is designed to adjust an overhang amount, i.e., the amount of the diameter of the second enclosing circle connecting the edge regions of the spheres 242 that projects radially beyond the diameter of the first enclosing circle connecting the edge regions of the rollers 241. As shown in Fig. 9 and Fig. As shown in Figure 10, the overhang adjustment mechanism 203 is composed of: the retainer 204, which rotatably holds twelve rotators 205; thin adjustable rings 206a, 206b and 206c (corresponding to adjustable rings of the present invention), which are designed to set an axial position of the retainer 204; a locking pin 207; and a spacer 208.

[0079] The retainer 204 is formed from a cylindrical link having a diameter slightly larger than that of the stepped shaft section 234 of the mandrel 230. The twelve rotators 205 are arranged circumferentially at uniform intervals on an outer surface of the retainer 204. Each of the rotators 205 has a tapered shape, with its diameter decreasing gradually towards its tip. Thus, the diameter (diameter DC in Fig. 10) of a third enveloping circle connecting the boundary regions of the rotators 205, at position P in Fig. 9, when the retainer 204 is moved axially on the stepped shaft section 234. More precisely, the diameter DC at position P is increased when the retainer 204 is moved to the tip side (the left side in Fig. 9) is moved. On the other hand, the diameter DC at position P decreases when the retainer 204 moves towards the rear side (the right side in Fig. 9) of the polishing tool 201. It should be noted that position P corresponds to the intersection of a perpendicular line drawn from the center of the sphere 242 to the central axis of the retainer 204 with the central axis of the retainer 204.

[0080] As from Fig. As becomes clear in Figure 10, the rotators 205, held by the retainer 204, are designed to engage with the balls 242, which are held by the frame 240. With this structure, the protrusions of the balls 242, which are radially advanced (pressed) by the rotators, increase, while the diameter DC of the third enclosing circle connecting the end regions of the rotators 205 increases. Thus, the diameter DB of the second enclosing circle connecting the diameters of the end regions 242 also increases. On the other hand, the difference between the diameter DA and the diameter DB increases with the increase in diameter DC because the diameter DA of the first enclosing circle connecting the end regions of the rollers 241 remains unchanged. In other words, the protrusion of the balls 242 increases. Conversely, the protrusions of the balls 242, which are radially advanced by the rotators 205, decrease, while the diameter DC decreases.Thus, the diameter DB decreases, so the difference between the diameter DA and the diameter DB decreases. Consequently, the protrusions of the spheres 242 decrease. In this way, the protrusions of the spheres 242 are adjusted.

[0081] It should be noted that the rotators 205 have the same skew angle or taper angle as the first tapered section 233a and the second tapered section 233b. Therefore, the diameter DA of the first enclosing circle connecting the edge regions of the rollers 241 and the diameter DB of the second enclosing circle connecting the edge regions of the balls 242 change simultaneously by the same amount when the mandrel 230 is moved axially. Furthermore, the retainer 204 is integrally attached to the stepped shaft section 234 by the locking pin 207, so that the retainer 204 is rotated within the frame 240 by the rotation of the mandrel 230.

[0082] The axial position of the retainer 204 can also be changed by altering the mounting positions between the thin adjustable rings 206a, 206b, and 206c. Note that in this embodiment, the thin adjustable ring 206a has a ring width t = 1 mm; the thin adjustable ring 206b has a ring width t = 1.5 mm; and the thin adjustable ring 206c has a ring width t = 2 mm. For example, the thin adjustable ring 206a with t = 1 mm is attached to a rear end face of the retainer 204 if the protrusion of the ball 242, i.e., a value determined by (diameter DB - diameter DA) / 2, is desired to be 20 µm, and the remaining thin adjustable rings 206b and 206c are attached to a tip face of the retainer 204.

[0083] Alternatively, the thin adjustable ring 206b with t = 1.5 mm is attached to the rear side of the retainer 204 if the projection of the ball 242 is desirablely 22.5 µm, and the remaining adjustable rings 206a and 206c are attached to the tip side of the retainer 204. The thin adjustable ring 206c with t = 2 mm is also attached to the rear side of the retainer 204 if the projection of the ball 242 is desirablely 25 µm, and the remaining thin adjustable rings 206a and 206b are attached to the tip side of the retainer 204.

[0084] Alternatively, the thin adjustable ring 206a with t = 1.0 mm and the thin adjustable ring 206b with t = 1.5 mm are mounted on the rear side of the retainer 204 if the projection of the ball 242 is desired to be 27.5 µm, and the remaining thin adjustable ring 206c is mounted on the tip side of the retainer 204. Similarly, the thin adjustable ring 206a with t = 1.0 mm and the thin adjustable ring 206c with t = 2 mm are mounted on the rear side of the retainer 204 if the projection of the ball 242 is desired to be 30 µm, and the remaining thin adjustable ring 206b is mounted on the tip side of the retainer 204. Obviously, the number and diameters of the thin adjustable rings can be adjusted as needed, depending on the required specifications.

[0085] Processes or procedures for forming depressions in the inner surface of the workpiece W will now be described using the polishing tool 201 constructed as described above. <einstellvorgang>

[0086] In an adjustment procedure, the axial position of the retainer is first adjusted to set the protrusion of the ball 242. More precisely, the thin adjustable rings 206a, 206b, and 206c are appropriately positioned at the front and rear of the retainer 204 in the axial direction, corresponding to a selection of the protrusion values ​​of the ball 242 described above, i.e., 20 µm, 22.5 µm, 25 µm, 27.5 µm, and 30 µm. This procedure completes the adjustment of the protrusion of the ball 242.

[0087] Next, the tool diameter of the rollers 241 is adjusted. More precisely, the housing 213 is moved to one drive side of the mandrel 230, i.e., to the side of the shank 232, to set the tool diameter. Then, the housing 213 is rotated to the right or left to set the desired tool diameter, as rotating the housing 213 to the right increases the tool diameter and rotating it to the left decreases it. After the housing 213 has been rotated to a position corresponding to the desired tool diameter, releasing the housing 213 causes it to return to its initial position under the restoring force of the spring 221, and the housing 213 is automatically locked against rotation. Thus, the tool diameter is set. Finally, the tips of the rollers 241 are measured with a micrometer to verify that the tool diameter is correctly set. <bearbeitungsvorgang>

[0088] In a machining operation, the mandrel 232 is first attached to a processing machine. Then, the polishing tool 201 is moved to a depression forming location on the inner surface of the workpiece W. It should be noted that the machining length of the workpiece W can be adjusted as desired using the polishing tool 201 by simply changing the stroke control settings of the processing machine. Next, the processing machine is driven to start the rotation of the mandrel 230. For example, each of the rollers 241 rotates counterclockwise (on its axis) along the outer surface of the mandrel 230 as the mandrel 230 rotates clockwise when viewed from its tip end.At this point, the counterclockwise rotation of rollers 241 causes roller 214 to rotate clockwise around the inner surface of workpiece W and the outer surface of mandrel 230, since workpiece W is fixed or clamped. At this point, rollers 241 are prevented from moving radially in and out of the frame because the outer surfaces of the first tapered section 233a and the second tapered section 233b have no rough areas. This allows an operator to stably polish the inner surface of workpiece W with rollers 241.

[0089] On the other hand, the movement of the balls 242 caused by the rotation of the mandrel 230 differs slightly from that of the rollers 241. Each of the balls 242 rotates clockwise while turning counterclockwise on its axis along the outer surface of the retainer 204 (in other words, along the third enclosing circle connecting the edge regions of the rotators 205). As the ball 242 rotates around the mandrel 230 while in a state of bidirectional repositioning between the inner surface of the workpiece W and the outer surface of the retainer 204, the ball 242 moves alternately through the rotators held by the retainer 204 and the outer surface of the retainer 204.Thus, the ball 242 rolls along the inner surface of the workpiece W, while it vibrates radially relative to the frame 240 due to the height differences between the outer surface of the retainer 204 and the rotators 205. This radial inward and outward movement of the ball 242 forms depressions in the inner surface of the workpiece W.

[0090] It should be noted that the retainer 204, which holds the multiple rotators 205 and has the function of causing the balls 242 to rotate as they move radially in and out of the frame, corresponds to a rotary section for rotating a pressure element of the present invention. Likewise, the first tapered section 233a and the second tapered section 233b, which have the function of causing the rollers 241 to rotate without moving radially in and out of the frame 240, correspond to a rotary section for rotating a roller element of the present invention. Additionally, a recess adjustment mechanism of the present invention comprises a retainer 204 holding the rotators 205, the first tapered section 233a, and the second tapered section 233b. <Werkzeugrückzug / entfernvorgang>

[0091] In the process of retracting or removing the tool, the polishing tool 201 is first moved out of the inner surface of the workpiece W. At this point, the spring 221 in the polishing tool 201 is moved into an extended position due to the frictional force (frictional resistance) between the spring 221 and the inner surface of the workpiece W, thereby moving the frame 240 forward relative to the mandrel 230. The diameter DA of the first enclosing circle connecting the edge regions of the rollers 241, i.e., the tool diameter, is then automatically reduced. This prevents the formation of redundant depressions during the process of returning the polishing tool 201 to its initial position. The depression formation process then ends when the polishing tool 201 is returned to its initial position and removed from the processing machine.

[0092] Fig. 12A shows the shape of depressions formed in this way. On the other hand, it shows Fig. 12B shows the shape of depressions formed with a polishing tool according to the related technology. As from a comparison between Fig. 12A and Fig. As becomes clear in 12B, the protrusion of the balls 242 in the polishing tool according to the third embodiment can be adjusted without changing the tool diameter, thus allowing an adjustment of the recess depth.

[0093] This means that in the polishing tool 201 according to the third embodiment, a correct recess shape that meets the conditions of use can be formed by adjusting the protrusion of the balls 242. As a result, the inner surface of the workpiece W is given excellent lubricating properties.

[0094] In the polishing tool 201 according to the third embodiment, the shot peening effect can also increase the surface hardness of the inner surface of the workpiece W and exert residual compressive stress on the workpiece surface, thereby improving the fatigue strength of the workpiece surface. Additionally, in the structure in which the balls 242 are used as pressure elements, for example, in a case where oil holes are formed in a direction intersecting the inner surface of the workpiece W, the balls 242 strike or press against edge sections around the oil holes, thereby allowing for the simultaneous removal of burrs on the edge sections of the oil holes.

[0095] Furthermore, in the polishing tool 201 according to the third embodiment, rollers 241 are provided on the tip side and the rear side of the ball 242. Thus, even in a case such as one in which there is a groove, notch, or notch in the inner surface of the workpiece W, at least one of the rollers 241 on the tip side and one of the rollers 241 on the rear side can be brought into contact with the inner surface of the workpiece W, thereby maintaining the sun-and-planet movement of the frame 204 and enabling the formation of the depression.

[0096] Next, the first and second modifications of the polishing tool 201 according to the third embodiment will be described. It should be noted that the same elements as those of the polishing tool 201 are designated by the same reference numerals and their description will not be repeated. First, the following will be shown: Fig. 13 a polishing tool 301 according to the first modification. The main feature of the polishing tool 301 is that the rollers 241 are not positioned further towards the tip than the balls 242. Even with this structure, if there is a groove in the inner surface of the workpiece W, the rollers 241, which are positioned further towards the rear than the balls 242, can be brought into contact with the inner surface of the workpiece W, thus maintaining the sun and planet movement of the frame 240 and enabling the formation of the depression.

[0097] It also shows Fig. 14 a polishing tool 401 according to the second modification. The main feature of the second modification is that the rollers 241 are not positioned further towards the rear than the balls 242. Even with this structure, in a case where there is a groove on the inner surface of the workpiece W, the rollers 241, which are positioned closer to the tip side than the balls 242, can be brought into contact with the inner surface of the workpiece W, thereby maintaining the sun-and-planet motion of the frame 240 and enabling the formation of the depression.

[0098] Although embodiments and modifications of the present invention have been described above, it should be understood that the invention is not limited to the embodiments and modifications described above but can be carried out with various changes.< / bearbeitungsvorgang> < / einstellvorgang> < / bearbeitungsvorgang> < / einstellvorgang>

Claims

[1] Polishing tool forming depressions (1), comprising: a mandrel (30) which is attached to a processing machine for rotation on a rear side belonging to it; and a cylindrical frame (40) rotatably mounted externally on a tip side of the mandrel (30), the frame holding a roller element (41) and a pressure element (42), the roller element (41) and the pressure element (42) being driven by rotation of the mandrel (30) to form depressions by the pressure element (42) and depressions by the roller element (41) in an inner surface of a workpiece (W) by rotation of the mandrel (30) with the frame (40) arranged within the inner surface of the workpiece (W), wherein the mandrel (30) has a recess adjustment mechanism, the recess adjustment mechanism comprising: a rotating section for the rolling element (41) which causes the rolling element to rotate without moving radially in and out of the frame (40); and a rotary section for rotating the pressure element (42) in and out, which causes the pressure element (42) to rotate while moving radially in and out of the frame (40). [2] A polishing tool forming depressions (1) according to claim 1, wherein the roller element (41) contains a plurality of rollers and the pressure element (42) contains a plurality of balls, the plurality of rollers and balls being spaced apart alternately on the same circumference of the frame (40), each roller being arranged with its axis parallel to an axis of the frame (40); the rollers have a length that is greater than the diameter of each ball; the thorn (30) has a tapered section on a tip side belonging to it, which gradually decreases in diameter towards a tip of the thorn (30); the tapered section has a first area and a second area on an outer surface belonging to it, wherein the first area serves as the rotary section for turning the pressure element (42) in and out, wherein the second area is arranged on both sides of the first area in an axial direction of the mandrel (30), wherein the second area serves as the rotary section for the rolling element (41); the first area has a plurality of flat sections spaced apart in the circumferential direction, the first area having a polygonal cross-section, while the second area has a circular cross-section; the flat sections have a length that is greater than the diameter of each sphere and less than the length of each roller; and the rollers are brought into contact with the second area without touching the flat sections of the first area when the frame (40) is attached to the mandrel (30), while the balls are only brought into contact with the first area. [3] A polishing tool (1) forming depressions according to claim 1, wherein the roller element (41) contains a plurality of rollers and the pressure element (42) contains a plurality of special rollers, wherein the plurality of rollers and special rollers are spaced alternately apart on the same circumference of the frame (40), wherein both each roller and each special roller are arranged with their respective axis parallel to an axis of the frame (40); Each of the special rollers has a ring that rotates around an axis belonging to it, and a pin that holds the ring, the ring having an outer surface with a pointed shape; the rollers have a length that is greater than the thickness of the ring; the thorn (30) has a tapered section on a tip side belonging to it, which gradually decreases in diameter towards a tip of the thorn (30); the tapered section has a first area and a second area on an outer surface belonging to it, wherein the first area serves as the rotary section for turning the pressure element (42) in and out, the second area is arranged on both sides of the first area in an axial direction of the mandrel (30) and the second area serves as the rotary section for the rolling element (41); the first area has a plurality of flat sections spaced apart in the circumferential direction, the first area having a polygonal cross-section, while the second area has a circular cross-section; the flat sections have a length that is greater than the thickness of the ring and less than the length of each roller; and The rollers are brought into contact with the second area without touching the flat sections of the first area when the frame is attached to the mandrel, while the ring is only brought into contact with the first area. [4] A polishing tool (1) forming depressions according to claim 2 or 3, further comprising a tool diameter adjustment mechanism, wherein the tool diameter adjustment mechanism adjusts a tool diameter, wherein the tool diameter is a diameter of a first enclosing circle connecting edge regions of the plurality of rollers. [5] A polishing tool forming depressions (1) according to claim 1, wherein the roller element (41) contains a plurality of rollers, the plurality of rollers being spaced apart from each other on a first circumference of the frame (40), each roller being arranged with its axis parallel to an axis of the frame (40); the pressure element (42) contains a plurality of spheres, wherein the plurality of spheres are spaced apart from each other on a second circumference of the frame (40), the second circumference being axially spaced from the first circumference with respect to the frame (40); the mandrel (30) gradually decreases in diameter towards a tip belonging to it, the mandrel (30) having a tapered section which serves as the rotating section for the rolling element (41) and a stepped shaft section which is deeper than the tapered section; the stepped shaft section is provided from the outside with a retainer, wherein the retainer holds a plurality of rotators and serves as the rotating section for turning the pressure element (42) in and out, wherein the plurality of rotators are driven by the rotation of the mandrel (30); The retainer holds the multiple rotators in such a way that the rotators are spaced apart from each other on the same circumference of the retainer, and in such a way that each of the rotators protrudes partially through an outer surface of the retainer; and the rollers are brought into contact with the tapered section when the frame is attached to the mandrel (30), while the balls are brought into contact with the retainer holding the majority of the rotators. [6] Polishing tool forming depressions (1) according to claim 5, further comprising: a tool diameter setting mechanism that sets a tool diameter, wherein the tool diameter is a diameter of a first enclosing circle connecting edge regions of the plurality of rollers; and an overhang adjustment mechanism that sets an overhang amount, wherein the overhang amount is an amount of a second enveloping circle connecting edge regions of the plurality of spheres, which projects radially out of the frame beyond the first enveloping circle, where the overhang adjustment mechanism sets the overhang amount to a different amount without changing the tool diameter. [7] A depression-forming polishing tool (1) according to claim 6, wherein the tool diameter adjustment mechanism moves the plurality of rollers and balls simultaneously radially with respect to the frame in order to adjust the tool diameter without changing the amount of overhang. [8] A polishing tool (1) forming depressions according to claim 6 or 7, wherein the overhang adjustment mechanism is attached to the stepped shaft section from the outside and has a plurality of adjustable rings, wherein the plurality of adjustable rings sets the axial position of the retainer to a predetermined position; the rotators have an outer surface with a tapered shape, which gradually decreases in diameter towards a tip belonging to them; the diameter of a third enclosing circle, the boundary regions of the majority of rotators, changes according to the axial position of the retainer; and The excess amount is adjusted by changing the axial position of the retainer. [9] A polishing tool (1) forming depressions according to claim 8, wherein the tapered section and the rotators have the same angle of inclination.

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