JP2016078166A - Roller burnishing processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roller burnishing processing device capable of heightening processing efficiency of the outer peripheral surface of a shaft part of a crank shaft by a simple constitution, while avoiding interference of a balance weight.SOLUTION: A roller burnishing processing device 10 includes a pair of burnishing rollers 14, 16 extending along the axial direction of a crank shaft 100, a pressing mechanism 18 and a support part 20. The pressing mechanism 18 has a first backup roller 22, and the burnishing rollers 14, 16 have a contact with a shaft part 102 in the juxtaposed state along the circumferential direction of the shaft part 102 of the crank shaft 100.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a roller burnishing apparatus that burnishes the outer peripheral surface of a shaft portion of a crankshaft.

  Vanishing is performed by, for example, pressing a processing tool (diamond tip) on the surface of a metal workpiece in a point-contacted manner and moving it relatively, and in a relatively short time without generating chips. There is an advantage that the surface of the workpiece can be smoothed.

  However, when this type of burnishing is applied to the outer peripheral surface of the shaft portion of the crankshaft, the processing tool may drop into the oil supply hole opened in the outer peripheral surface, or the processing tool and the balance weight may interfere with each other. .

  For example, in Patent Documents 1 and 2, one burnish roller extending in the axial direction of the crankshaft is pressed and rolled in a state of being in line contact with the outer peripheral surface of the shaft portion of the crankshaft so as to reach the oil supply hole. There has been proposed a roller burnishing apparatus that burnishes the outer peripheral surface of the shaft portion of the crankshaft while suppressing the drop of the burnish roller (processing tool).

  Further, Patent Document 1 discloses a technical idea of avoiding balance weight interference by transmitting a pressing force of a hydraulic cylinder to a burnish roller via one backup roller.

JP-A-6-190718 Japanese Patent No. 3690394

  In the prior art described above, as shown in FIG. 9, one burnish roller 200 is pressed against the outer peripheral surface of the shaft portion of the crankshaft 202 in a line-contact state, so that the burnish roller 200 is pressed against the shaft portion of the crankshaft 202. It may be slippery in the circumferential direction with respect to the outer peripheral surface, and the pressing force may not be efficiently applied to the outer peripheral surface of the shaft portion of the crankshaft 202. Therefore, the processing efficiency of the outer peripheral surface of the shaft portion of the crankshaft 202 may be reduced.

  The present invention has been made in consideration of such problems, and a roller burnish processing apparatus capable of increasing the processing efficiency of the outer peripheral surface of the shaft portion of the crankshaft with a simple configuration while avoiding balance weight interference. The purpose is to provide.

  In order to achieve the above object, a roller burnishing apparatus according to the present invention is a roller burnishing apparatus that burns the outer peripheral surface of a shaft portion of a crankshaft, and extends along the axial direction of the crankshaft. A pair of burnish rollers having an outer diameter smaller than the outer diameter of the shaft portion of the crankshaft, support means for rotatably supporting the pair of burnish rollers, and each vanish roller facing the shaft portion of the crankshaft A pressing mechanism that presses and presses, and the pressing mechanism has a first backup roller that rotates in contact with the outer peripheral surface of each of the burnish rollers, and the pair of burnish rollers are provided on the shaft portion of the crankshaft. It contacts the outer peripheral surface of the axial part of the said crankshaft in the state arranged in parallel along the circumferential direction, It is characterized by the above-mentioned.

  According to such a configuration, the pair of burnish rollers arranged in parallel along the circumferential direction of the shaft portion of the crankshaft are brought into contact with the outer peripheral surface of the shaft portion of the crankshaft. It is possible to make it difficult to slip in the circumferential direction with respect to the outer peripheral surface of the. As a result, a predetermined pressing force can be efficiently applied from the pressing mechanism to the outer peripheral surface of the shaft portion of the crankshaft via each burnish roller, so that the processing efficiency of the shaft portion can be increased with a simple configuration. it can. In addition, since the pressing force is transmitted to each burnish roller via the first backup roller, interference between the balance weight and the pressing mechanism can be avoided.

  In the above roller burnishing apparatus, the pair of burnish rollers have the same outer diameter, and are equidistant from a line segment connecting the axis of the crankshaft shaft and the rotation axis of the first backup roller. The positions may be spaced apart from each other.

  According to such a configuration, substantially the same pressing force can be transmitted to each burnish roller via the first backup roller, and the pair of burnish rollers are circumferentially arranged with respect to the outer peripheral surface of the shaft portion of the crankshaft. It is possible to make it more difficult to slip.

  In the roller burnishing apparatus, the pressing mechanism may include a second backup roller that rotates in contact with the outer peripheral surface of the first backup roller.

  According to such a configuration, since the first backup roller and the second backup roller are used, it is possible to avoid interference between the balance weight of the crankshaft and the pressing mechanism while reducing the size of the pressing mechanism.

  In the above roller burnishing apparatus, the support means is disposed so as to sandwich the pair of burnish rollers, and rotates in contact with the outer peripheral surface of the burnish roller. And a retainer.

  According to such a structure, it can suppress that the outer peripheral surface of a burnish roller contacts a retainer, and is damaged, Therefore A high processing precision can be maintained.

  In the roller burnishing apparatus described above, the outer diameter of each of the burnish rollers may be set to a size of 1/10 or more and 1/5 or less of the outer diameter of the shaft portion of the crankshaft.

  According to such a configuration, it is possible to more efficiently apply the pressing force to the outer peripheral surface of the shaft portion of the crankshaft while suppressing breakage of the burnish roller.

  According to the present invention, a pair of burnish rollers arranged side by side along the circumferential direction of the shaft portion of the crankshaft is brought into contact with the outer peripheral surface of the shaft portion of the crankshaft, and is pressed against each burnish roller via the first backup roller. Since the pressure is transmitted, the processing efficiency of the outer peripheral surface of the shaft portion of the crankshaft can be increased with a simple configuration while avoiding the interference of the balance weight.

It is a schematic diagram of a roller burnishing apparatus and a crankshaft according to an embodiment of the present invention. It is a longitudinal cross-sectional view along the II-II line of FIG. It is a longitudinal cross-sectional view along the III-III line of FIG. It is a top view of the support part shown in FIG. It is explanatory drawing which shows the positional relationship of a pair of burnish roller. It is a top view of the support part concerning a modification. FIG. 7A is an explanatory view of a roller burnishing apparatus according to a modified example including two receiving rollers, and FIG. 7B is an explanatory view of a roller burnishing apparatus according to a modified example including three receiving rollers. It is explanatory drawing of the roller burnishing apparatus which concerns on the modification provided with two process part main bodies. It is explanatory drawing of the burnishing which concerns on a prior art.

  Hereinafter, a preferred embodiment of a roller burnishing apparatus according to the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, the roller burnishing apparatus 10 according to the present embodiment performs burnishing (burnishing) on the shaft portion 102 (crank journal 104 and crank pin 106) of the crankshaft 100.

  First, the crankshaft 100 as a workpiece will be described. The crankshaft 100 is used as a component part of an engine such as an automobile, for example, and a plurality of crank journals 104 pivotally supported by a cylinder block (not shown), a plurality of crankpins 106 to which a connecting rod of a piston (not shown) is attached, A plurality of crank arms 108 for connecting the crank journal 104 and the crank pin 106 and a plurality of balance weights 110 provided on the crank arm 108 are provided.

  The axis line Ax1 of the crank journal 104 and the axis line Ax2 of the crankpin 106 extend in parallel at positions that do not overlap each other. As shown in FIG. 3, an arcuate fillet portion 112 is formed between the crank journal 104 and the crank arm 108 (boundary portion) and between the crank pin 106 and the crank arm 108 (boundary portion). ing. An oil supply hole 114 is opened on the outer peripheral surfaces of the crank journal 104 and the crankpin 106.

  As shown in FIGS. 1 to 3, the roller burnishing apparatus 10 includes a processing unit main body 12 attached to a moving mechanism (not shown). The processing unit main body 12 includes a pair of burnish rollers 14 and 16 configured in a columnar shape or a cylindrical shape, a pressing mechanism 18 that presses the burnish rollers 14 and 16 toward the shaft portion 102 of the crankshaft 100, and a burnish roller. And a support portion (support means) 20 for supporting the members 14 and 16.

  The pair of burnish rollers 14 and 16 are juxtaposed along the circumferential direction of the shaft portion 102 of the crankshaft 100 in a state of extending along the axial direction (arrow X direction) of the crankshaft 100. The overall lengths of the burnishing rollers 14 and 16 are set slightly longer than the width of the shaft portion 102 that performs burnishing on the crankshaft 100. Thereby, the outer peripheral surface of the axial part 102 of the crankshaft 100 can be burnished efficiently.

  The pair of burnish rollers 14 and 16 have the same outer diameter. The outer diameters of the burnish rollers 14 and 16 are set to be smaller than the outer diameter of the shaft portion 102 where the burnishing process is performed on the crankshaft 100. Specifically, the outer diameter of each of the burnish rollers 14 and 16 is preferably set to a size of 1/10 or more and 1/5 or less of the outer diameter of the shaft portion 102.

  If the outer diameter of the burnish rollers 14 and 16 is smaller than 1/10 of the outer diameter of the shaft portion 102, the burnish rollers 14 and 16 are easily damaged, and the outer diameter of the burnish rollers 14 and 16 is smaller than the outer diameter of the shaft portion 102. This is because if the diameter is larger than 1/5 of the diameter, the pressing force cannot be efficiently increased on the outer peripheral surface of the shaft portion 102.

  The pressing mechanism 18 includes first to third backup rollers 22, 24, and 26 that rotate as the pair of burnish rollers 14 and 16 rotate, and first to third shafts that support the first to third backup rollers 22, 24, and 26. 1st to 3rd support shafts 28, 30, 32, a holder 34 that holds the 1st to 3rd support shafts 28, 30, 32, a plurality of disc springs (biasing means) 36 that press the holder 34, and a plurality of And a spring support portion 38 for supporting the disc spring 36.

  The first backup roller 22 is in contact with the outer peripheral surfaces of the pair of burnish rollers 14 and 16 while being supported by the first support shaft 28. The second backup roller 24 is in contact with the outer peripheral surface of the first backup roller 22 while being supported by the second support shaft 30. The third backup roller 26 is in contact with the second backup roller 24 while being supported by the third support shaft 32.

  The first to third support shafts 28, 30, and 32 extend along the axial direction of the crankshaft 100. In other words, the axis lines Ax3, Ax4, Ax5 of the first to third support shafts 28, 30, 32 extend in parallel to the axis lines Ax1, Ax2 of the shaft portion 102 of the crankshaft 100.

  The holder 34 includes a pair of cover portions 40, 42 disposed so as to sandwich the first to third backup rollers 22, 24, 26 from the axial direction of the crankshaft 100, and a plurality of fastening portions for fastening the cover portions 40, 42. It includes a bolt 44 and a connecting portion 46 that is provided at an end of each cover portion 40, 42 opposite to the side where the burnish rollers 14, 16 are located and connects the cover portions 40, 42.

  Each of the cover portions 40 and 42 is formed with a thin tip end side close to the burnish rollers 14 and 16 and a base end side close to the connecting portion 46 formed thick. Specifically, the cover portions 40 and 42 each have a thin portion covering the first backup roller 22 and the second backup roller 24 and a thick portion covering the third backup roller 26. Thereby, since the thickness dimension of the front end side of the press mechanism 18 can be made comparatively small, interference with the press mechanism 18 and the balance weight 110 can be avoided.

  The number and size of the disc springs 36 are set according to the surface roughness required for the outer peripheral surface of the shaft portion 102 of the crankshaft 100. In the present embodiment, a plurality of disc springs 36 are used as urging means for pressing the holder 34 in order to reduce the size of the pressing mechanism 18, but the urging means may be a coil spring or the like. The spring support portion 38 is a block-like member in which an arrangement hole 48 in which a plurality of disc springs 36 are arranged is formed. The spring support portion 38 is provided on the bottom surface of the arrangement hole 48 and is arranged on each of the disc springs 36. It has the support | pillar 50 penetrated to a center hole.

  As shown in FIG. 4, the support portion 20 includes a pair of retainers 54 and 56 attached to the cover portions 40 and 42 by a plurality of bolts 52, and a pair of guide rollers 58 pivotally supported by the retainers 54 and 56. 60.

  The retainers 54 and 56 are formed in a substantially U shape in plan view, and the burnish rollers 14 and 16 and the guide rollers 58 and 60 are arranged in the internal space of the U shape. The pair of retainers 54 and 56 are arranged in parallel at a predetermined distance from each other in a direction orthogonal to the axial direction of the burnish rollers 14 and 16 so that the U-shaped openings face each other. The spacing between the pair of retainers 54 and 56 can be set arbitrarily, but is set smaller than the outer diameter of the burnish rollers 14 and 16, for example.

  The pair of guide rollers 58 and 60 are disposed so as to sandwich the pair of burnish rollers 14 and 16. Each of the guide rollers 58 and 60 extends along the axial direction of the burnish rollers 14 and 16, and both end portions thereof are formed with a small diameter and the central portion thereof is formed with a large diameter.

  As a result, as can be understood from FIG. 4, the outer peripheral surfaces of the large-diameter portions of the guide rollers 58 and 60 rotate in contact with the outer peripheral surfaces of the burnish rollers 14 and 16. Although the outer diameter of the large diameter part of the guide rollers 58 and 60 can be set arbitrarily, it can be set, for example, substantially the same as the outer diameter of the burnish rollers 14 and 16. Accordingly, the pair of guide rollers 58 and 60 can be reliably supported while avoiding contact with the crankshaft 100 and the first backup roller 22.

  In the support part 20 configured in this way, the burnish rollers 14 and 16 are supported so that their outer peripheral surfaces can rotate without contacting the retainers 54 and 56. Therefore, since the outer peripheral surfaces of the burnish rollers 14 and 16 are prevented from coming into contact with the retainers 54 and 56 and damaged, high machining accuracy is maintained.

  Further, as shown in FIG. 5, the pair of burnish rollers 14 and 16 includes the axis lines Ax1 and Ax2 of the shaft portion 102 of the crankshaft 100 and the axis line Ax3 of the first support shaft 28 (the rotation axis of the first backup roller 22). Are spaced apart from each other at equidistant positions d from the line segment L.

  The roller burnishing apparatus 10 according to the present embodiment is basically configured as described above. Next, the operation and effect of the apparatus will be described.

  First, when the outer peripheral surface of the shaft portion 102 of the crankshaft 100 is burnished, for example, the crankshaft 100 is mounted on a rotary drive device (not shown) and rotated. At this time, when the outer peripheral surface of the crank journal 104 is burnished, the crankshaft 100 is rotated so that the axis Ax1 of the crank journal 104 becomes the rotation axis, and when the outer peripheral surface of the crankpin 106 is burnished, The crankshaft 100 is rotated so that the axis Ax2 of the pin 106 becomes the rotation axis. It is assumed that the pair of burnish rollers 14 and 16 of the roller burnishing apparatus 10 are waiting in the vicinity of the shaft portion 102 of the crankshaft 100 that performs burnishing.

  Subsequently, when the rotational speed of the shaft portion 102 of the crankshaft 100 reaches a predetermined rotational speed, the roller burnishing apparatus 10 brings the pressing mechanism 18 close to the shaft portion 102 of the crankshaft 100 by a moving mechanism (not shown). The burnish rollers 14 and 16 are brought into line contact with the outer peripheral surface of the shaft portion 102. At this time, the pair of burnish rollers 14 and 16 are juxtaposed along the circumferential direction of the shaft portion 102 of the crankshaft 100, so that it is difficult to slide in the circumferential direction with respect to the outer peripheral surface of the shaft portion 102. In other words, the pair of burnish rollers 14 and 16 stably makes line contact with the outer peripheral surface of the shaft portion 102 of the crankshaft 100.

  Further, since the pressing force of the plurality of disc springs 36 is transmitted approximately equally to the pair of burnish rollers 14 and 16 via the first to third backup rollers 22, 24 and 26, each of the burnish rollers 14 and 16 has a predetermined value. The outer peripheral surface of the shaft portion 102 is rolled while being pressed against the outer peripheral surface of the shaft portion 102 of the crankshaft 100 by a pressing force (Hertz surface pressure). At this time, the pressing force of the disc spring 36 is transmitted to the burnish rollers 14 and 16 by the first to third backup rollers 22, 24 and 26, so that the pressing mechanism 18 and the balance weight 110 do not interfere with each other. .

  Each of the burnish rollers 14 and 16 is allowed to rotate by the first to third backup rollers 22, 24 and 26 and the pair of guide rollers 58 and 60, so that the outer peripheral surface of the shaft portion 102 of the crankshaft 100 is provided. It will roll smoothly. As a result, the outer peripheral surface of the shaft portion 102 of the crankshaft 100 is plastically deformed (burnished) and smoothed.

  According to the present embodiment, the pair of burnish rollers 14 and 16 arranged in parallel along the circumferential direction of the shaft portion 102 of the crankshaft 100 are in line contact with the outer peripheral surface of the shaft portion 102 of the crankshaft 100. Each of the burnish rollers 14 and 16 can be made difficult to slide in the circumferential direction with respect to the outer peripheral surface of the shaft portion 102. Accordingly, a predetermined pressing force can be efficiently applied from the pressing mechanism 18 to the outer peripheral surface of the shaft portion 102 of the crankshaft 100 via the burnish rollers 14 and 16, so that the shaft portion 102 can be configured with a simple configuration. The processing efficiency can be improved.

  Further, since the outer diameters of the burnish rollers 14 and 16 are made smaller than the outer diameter of the shaft portion 102 of the crankshaft 100, it is possible to efficiently apply a pressing force to the outer peripheral surface of the shaft portion 102. it can. Further, since the pressing force can be transmitted to the burnishing rollers 14 and 16 via the first backup roller 22, a predetermined pressing force is applied to each of the burnishing rollers 14 and 16 while allowing the rotation of the burnishing rollers 14 and 16. Pressure can be applied. Furthermore, since the first to third backup rollers 22, 24, 26 are used, it is possible to avoid interference between the balance weight 110 and the pressing mechanism 18 while reducing the size of the pressing mechanism 18.

  In this embodiment, a pair of burnish rollers 14 and 16 having the same outer diameter are connected to the axis of the shaft portion 102 of the crankshaft 100 (the axis Ax1 of the crank journal 104 or the axis Ax2 of the crankpin 106) and the first support shaft 28. Are spaced apart from each other at a position equidistant from a line segment L connecting the axis Ax3 (the rotation axis of the first backup roller 22). Therefore, substantially equal pressing force can be transmitted to each of the burnish rollers 14 and 16 via the first to third backup rollers 22, 24 and 26, and the pair of burnish rollers 14 and 16 are connected to the shaft of the crankshaft 100. It is possible to make it more difficult to slide in the circumferential direction with respect to the outer peripheral surface of the portion 102.

  According to the present embodiment, the pair of guide rollers 58 and 60 disposed so as to sandwich the pair of burnish rollers 14 and 16 are rotated in contact with the outer peripheral surfaces of the burnish rollers 14 and 16. Therefore, it is possible to prevent the outer peripheral surfaces (rolling surfaces) of the burnish rollers 14 and 16 from coming into contact with the retainers 54 and 56 so that high machining accuracy can be maintained.

  In addition, since the outer diameter of each burnish roller 14, 16 is set to 1/10 or more and 1/5 or less of the outer diameter of the shaft portion 102 of the crankshaft 100, the outer diameter of the shaft portion 102 is pushed. Pressure can be applied efficiently. Therefore, the processing efficiency of the outer peripheral surface of the shaft portion 102 of the crankshaft 100 can be further improved.

  The present embodiment is not limited to the above-described configuration and burnishing method. For example, when the outer peripheral surface of the crankpin 106 is burnished, the crankshaft 100 is rotated so that the axis line Ax1 of the crank journal 104 becomes the rotation axis, and the pair of burnish rollers 14 and 16 are pressed against the outer peripheral surface of the crankpin 106. The burnishing may be performed by rotating the pressing mechanism 18 around the axis of the crank journal 104 while rotating the pressing mechanism 18 around the axis of the crank journal 104.

  When the outer peripheral surface of the crank journal 104 is burnished, the crankshaft 100 is rotated so that the axis Ax1 of the crank journal 104 becomes the rotation axis, and the pair of burnish rollers 14 and 16 are pressed against the outer peripheral surface of the crank journal 104. The burnishing may be performed by rotating the pressing mechanism 18 around the axis of the crank journal 104 in the state where it is in this state.

  Further, for example, the crankshaft 100 is fixed without rotating, and the pressing mechanism 18 is arranged around the axis of the shaft portion 102 in a state where the pair of burnish rollers 14 and 16 are pressed against the outer peripheral surface of the shaft portion 102 of the crankshaft 100. Vanishing may be performed by rotating.

  The roller burnishing apparatus 10 according to the present embodiment may have a support portion 20a according to a modification shown in FIG. In the support portion 20a, the burnish rollers 14 and 16 are pivotally supported with respect to the retainers 54 and 56, and the pair of guide rollers 58 and 60 are omitted. Even in such a configuration, an appropriate pressing force is applied to the outer peripheral surface of the shaft portion 102 of the crankshaft 100 while preventing the outer peripheral surfaces of the burnish rollers 14 and 16 from coming into contact with the retainers 54 and 56 and being damaged. The burnish rollers 14 and 16 can be rolled.

  As shown in FIG. 7A, the roller burnishing apparatus 10 may have a pair of receiving rollers 62 that support the shaft portion 102 of the crankshaft 100 from the side opposite to the burnish rollers 14 and 16. Thereby, since the bending of the axial part 102 of the crankshaft 100 can be suppressed, the pressing force (Hertz surface pressure) with respect to the outer peripheral surface of the said axial part 102 can be raised. Thereby, the processing efficiency of the axial part 102 of the crankshaft 100 can be improved further.

  The number and size of the receiving rollers 62 can be arbitrarily set. For example, as illustrated in FIG. 7B, the roller burnishing apparatus 10 may include a large-diameter receiving roller 64 and a pair of small-diameter receiving rollers 66 that rotate in contact with the outer peripheral surface of the receiving roller 64. Good. In this case, interference between the balance weight 110 and the receiving rollers 64 and 66 can be preferably avoided.

  Furthermore, as shown in FIG. 8, the roller burnishing apparatus 10 may include a plurality (two in the illustrated example) of processing unit main bodies 12. In this case, the plurality of processed portion main bodies 12 are disposed so as to face each other with the shaft portion 102 of the crankshaft 100 interposed therebetween. Thereby, the processing efficiency of the axial part 102 of the crankshaft 100 can further be improved.

  The roller burnishing apparatus according to the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Roller burnishing apparatus 12 ... Processing part main body 14, 16 ... Vanishing roller 18 ... Pressing mechanism 20, 20a ... Support part (support means) 22 ... 1st backup roller 24 ... 2nd backup roller 26 ... 3rd backup roller 34 ... Holder 36 ... Belleville spring 54, 56 ... Retainer 58, 60 ... Guide roller 100 ... Crank shaft 102 ... Shaft 104 ... Crank journal 106 ... Crank pin 110 ... Balance weight

Claims (5)

In a roller burnishing apparatus that burnishes the outer peripheral surface of the crankshaft shaft,
A pair of burnish rollers extending along the axial direction of the crankshaft and having an outer diameter smaller than the outer diameter of the shaft portion of the crankshaft;
Support means for rotatably supporting the pair of burnish rollers;
A pressing mechanism that presses each of the burnish rollers toward the shaft portion of the crankshaft,
The pressing mechanism has a first backup roller that rotates in contact with the outer peripheral surface of each of the burnish rollers,
The pair of burnish rollers are in contact with the outer peripheral surface of the shaft portion of the crankshaft in a state of being arranged in parallel along the circumferential direction of the shaft portion of the crankshaft. In the roller burnishing apparatus according to claim 1,
The pair of burnish rollers have the same outer diameter and are spaced apart from each other at equidistant positions from a line connecting the axis of the crankshaft shaft and the rotation axis of the first backup roller. A roller burnishing apparatus, characterized in that In the roller burnishing apparatus according to claim 1 or 2,
The roller burnishing apparatus, wherein the pressing mechanism includes a second backup roller that rotates in contact with an outer peripheral surface of the first backup roller. In the roller burnishing apparatus according to any one of claims 1 to 3,
The support means is disposed so as to sandwich the pair of burnish rollers, and a pair of guide rollers rotating in contact with the outer peripheral surface of the burnish roller;
A roller burnishing apparatus comprising a retainer that pivotally supports each of the guide rollers. In the roller burnishing apparatus according to any one of claims 1 to 4,
The roller burnishing apparatus according to claim 1, wherein an outer diameter of each of the burnish rollers is set to 1/10 or more and 1/5 or less of an outer diameter of a shaft portion of the crankshaft.

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