Wrapping device

Abstract

To polish an outer periphery part of a cam part and an outer periphery part of a shaft part of a cam shaft efficiently.SOLUTION: A wrapping device 1 includes: a rotary device 3 which is disposed on a table 2 and supports a cam shaft 20 in a manner that the cam shaft 20 may rotate around an axis C; a tape-like polishing member 4 wound around the outer periphery part of the cam part 22 of the cam shaft 20; a polishing member fixture 5 which fixes the polishing member 4; and a holding device 6 which may move in a direction along the axis C of the cam shaft 20 and a direction orthogonal to the axis C of the cam shaft 20. The polishing member fixture 5 has: a first block body 30 which fixes a portion, which extends from a wound portion wound around the outer periphery part of the cam part 22 of the cam shaft 20, of the polishing member 4; and a second block body 31 fixed to the holding device 6. The first block body 30 is supported so as to be slidable relative to the second block body 31 and biased toward the second block body 31.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a lapping device for polishing the outer periphery of a cam portion of a camshaft of an automobile or the like. [Background technology]

[0002] When polishing the outer periphery of the cam portion of a camshaft having multiple cam portions and journal portions, a lapping device is used which polishes the outer periphery of the cam portion of the rotating camshaft with a polishing member (see, for example, Patent Documents 1 and 2).

[0003] The lapping device (camshaft processing device) described in Patent Document 1 includes a work support unit that holds the camshaft in a rotating state, a cam polishing unit having a polishing member that polishes the cam portion, and a journal grinding unit having a grinding member that performs grinding on the journal portion (see Figure 7 of Patent Document 1).

[0004] The cam polishing unit of the lapping device described in Patent Document 1 includes a pair of rollers, a paper-like polishing member stretched between the pair of rollers, and a back shoe that presses the polishing member against the cam. In this lapping device, the polishing member of the journal grinding unit is brought close to the journal portion, and the polishing member of the cam polishing unit is brought close to the cam portion. After that, the grinding member of the journal grinding unit is brought into contact with the journal portion, and the polishing member of the cam polishing unit is brought into contact with the cam portion, allowing the journal portion to be ground and the cam portion to be polished simultaneously.

[0005] The lapping device (camshaft polishing device) described in Patent Document 2 includes a cylindrical hollow case, a polishing member attachment body arranged inside the case and for attaching a polishing member, a rotating shaft for rotating the polishing member attachment body, a motor for rotating the rotating shaft body about its axis, and an elastic body for biasing the polishing member in the direction of the cam portion and journal portion. The rotating shaft is arranged perpendicular to the axis of the camshaft.

[0006] In the lapping device of Patent Document 2, the camshaft is held in a rotating state around its axis, a polishing member is rotated at a low speed around the axis of the rotating shaft by a motor, and the polishing member rotating at a low speed is brought into contact (pressed against) the outer periphery of the cam portion of the camshaft by an elastic member. This makes it possible to polish the outer periphery of the cam portion of the camshaft. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2006-15432 A [Patent Document 2] JP 2007-229850 A Summary of the Invention [Problem to be solved by the invention]

[0008] In the lapping device described in Patent Document 1, a paper-like polishing member of a cam polishing unit is brought into contact with the outer periphery of the cam portion of the camshaft using a back shoe. In the lapping device described in Patent Document 2, the polishing member is brought into contact with the outer periphery of the cam portion of the camshaft using an elastic member. In this contact state, the polishing member is in contact with the outer periphery of the cam portion only in a limited range in the circumferential direction. As a result, the polishing area for the outer periphery of the cam portion is reduced, and there is a problem that it takes a long time to polish the outer periphery of the cam portion.

[0009] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to increase the polishing area of ​​the outer periphery of the cam portion of the camshaft. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention can employ the following configurations 1 to 5. [Configuration 1] A lapping device for polishing the outer periphery of a cam portion or the outer periphery of a shaft portion of a camshaft having multiple cam portions fixed thereto, the lapping device comprising: a rotating device for rotating the camshaft around an axis of the camshaft; a tape-shaped polishing member that is wrapped circumferentially around the outer periphery of the cam portion or the outer periphery of the shaft portion of the camshaft; and a polishing member fixing device for fixing first and second extension portions of the polishing member extending from a wrapping portion that is wrapped around the outer periphery of the cam portions or the outer periphery of the shaft portion.

[0011] [Configuration 2] The lapping device described in configuration 1, wherein the polishing member fixing device has a guide hole that guides the first extension portion and the second extension portion of the polishing member in a direction extending from the winding portion, and the first extension portion and the second extension portion of the polishing member are fixed to the polishing member fixing device in a state where they overlap each other.

[0012] [Configuration 3] A wrapping device of configuration 2, wherein the polishing member fixing device has a guide rail disposed inside the guide hole, the first extension portion and the second extension portion of the polishing member are fixed on the guide rail in an overlapping state, and the guide rail has a plurality of guide plate portions that restrict movement of the first extension portion and the second extension portion of the polishing member in a direction perpendicular to the direction in which they extend from the winding portion.

[0013] [Configuration 4] The lapping device according to any one of configurations 1 to 3, wherein the polishing member fixture is biased in a direction away from the axis of the camshaft along a direction extending from the wound portion of the polishing member.

[0014] [Configuration 5] 5. The lapping apparatus according to any one of configurations 1 to 4, further comprising a holding device provided at a position away from an axis of the camshaft, wherein the polishing member fixture has a first block body for fixing the first extension portion and the second extension portion of the polishing member, a second block body fixed to the holding device, and a guide shaft body for supporting the first block body slidably relative to the second block body in a direction extending from the wound portion of the polishing member, and the first block body is biased toward the second block body. Effect of the Invention

[0015] According to this invention, the outer periphery of the cam portion or the outer periphery of the shaft portion of the camshaft can be polished efficiently. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a plan view showing a wrapping device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a front view showing the wrapping device according to the first embodiment; [Diagram 3] FIG. 2 is a cross-sectional view showing the wrapping device taken along line AA in FIG. [Figure 4] FIG. 4 is a perspective view showing a polishing member fixing device of the lapping apparatus; [Diagram 5] FIG. 5 is a front view showing the abrasive member fixture taken along line BB in FIG. [Figure 6] FIG. 2 is an exploded perspective view showing a polishing member fixing device of the lapping apparatus; [Figure 7] FIG. 11 is an explanatory diagram showing a polishing state of the outer periphery of the cam portion of the lapping device in a state where the non-circular portion of the cam portion is positioned on the polishing member fixing tool side; [Figure 8] FIG. 11 is an explanatory diagram showing a polishing state of the outer periphery of the cam portion of the lapping device in a state where the non-circular portion of the cam portion is located on the opposite side to the polishing member fixing tool side; [Figure 9] FIG. 13 is a front view showing a polishing member fixing device using a modified example of the guide rail of the lapping device; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] A lapping device according to an embodiment of the present invention will be described with reference to Fig. 1 to Fig. 4. As shown in Fig. 1 and Fig. 2, the lapping device 1 polishes the outer periphery of the cam portions 22 or the outer periphery of the shaft portion 21 located between the cam portions 22 of a camshaft 20 having a plurality of cam portions 22 fixed at intervals to the shaft portion 21.

[0018] The lapping device 1 includes a table 2, a rotating device 3 arranged on the table 2 and supporting the camshaft 20 so that it can rotate around its axis C, a tape-shaped polishing member 4 that is wrapped around the outer periphery of the cam portion 22 of the camshaft 20, a polishing member fixture 5 that fixes the polishing member 4, and a holding device 6 that holds the polishing member fixture 5 on the table 2.

[0019] The rotating device 3 has a headstock 8 equipped with a spindle 7, and a tailstock 9 arranged at a position opposite to the headstock 8. The spindle 7 of the headstock 8 is rotated by a servo motor (not shown). The tailstock 9 is arranged so that its center is coaxial with the center (or chuck) of the spindle 7. The center (or chuck) of the spindle 7 and the center of the tailstock 9 clamp the camshaft 20 through a center hole (not shown) (or one end side of the camshaft 20 is chucked by the chuck at the outer periphery of the journal, and the other end side is pressed and held by the center). The spindle 7 is driven to rotate by a servo motor (not shown), and the camshaft 20 is rotated around the axis C in a state where it coincides with the Y axis. In the following description, the direction connecting the center of the spindle 7 and the tailstock 9 is defined as the Y axis, and the horizontal direction perpendicular to the Y axis is defined as the X axis.

[0020] The holding device 6 has a slide table 10 that is movable in the Y-axis direction (left and right direction) relative to the table 2, a holding table 11 that is movable in the X-axis direction (front and back direction) relative to the slide table 10, a fixing plate 12 that is fixed above the holding table 11, and a plurality of bolts 13 that are screwed downward into the fixing plate 12.

[0021] A ball screw 2a extending along the Y-axis direction and a servo motor 2b for rotating the ball screw 2a about its axis are arranged on the table 2. The ball screw 2a is screw-coupled to a nut (not shown) that supports the slide table 10. The ball screw 2a is rotated by the servo motor 2b, and the slide table 10 is moved in the Y-axis direction via the nut (not shown) (or by handle feed). The slide table 10 has a rectangular upper surface, and the long side edge of the slide table 10 is aligned along the Y-axis direction.

[0022] A ball screw 10a extending along the X-axis direction and a servo motor 10b for rotating the ball screw 10a about its axis are arranged on the slide base 10. The ball screw 10a is screwed into a nut (not shown) that supports the holder 11. The ball screw 10a is rotated by the servo motor 10b, and the holder 11 is moved in the X-axis direction via the nut (not shown) (or by handle feed). The holder 11 has a rectangular upper surface 11a. The upper surface 11a of the holder 11 is smaller than the upper surface of the slide base 10, and the edge on the camshaft 20 side is aligned along the Y-axis direction.

[0023] The fixed plate 12 is formed from a rectangular metal plate. The fixed plate 12 is disposed at a distance in the up-down direction from the holder 11 via a spacer 11b. The edge of the fixed plate 12 located on the camshaft 20 side is aligned along the Y-axis direction. The bolts 13 are disposed at the four corners of the fixed plate 12 and at the center of each edge. The threaded portions of the respective bolts 13 are located on the upper surface portion 11a of the holder 11 in a plan view.

[0024] The polishing member 4 is a long tape-like member, and is formed by electrostatically coating abrasive grains with a thermosetting adhesive on a substrate made of a synthetic resin film with a uniform thickness. For example, a polyester film with high tensile strength can be used as the substrate, and precisely classified aluminum oxide can be used as the polishing grains. The polishing member 4 has a width corresponding to the width of the cam portion 22 of the camshaft 20 in the Y-axis direction.

[0025] As shown in FIG. 3, the polishing member 4 is wound around the outer periphery of the cam portion 22 of the camshaft 20. The first extension portion 4b located on the upper side and the second extension portion 4c located on the lower side extending from the winding portion 4a wound around the outer periphery of the cam portion 22 of the polishing member 4 are fixed to the polishing member fixture 5 in a state of being mutually overlapped in the vertical direction. The direction in which the first extension portion 4b and the second extension portion 4c extend from the winding portion 4a of the polishing member 4 (the direction extending from the winding portion 4a of the polishing member 4) means the direction in which the first extension portion 4b and the second extension portion 4c extend from the winding portion 4a of the polishing member 4 in a plan view (the direction extending from the winding portion 4a of the polishing member 4) (see FIG. 1). The direction in which the first extension portion 4b and the second extension portion 4c extend from the winding portion 4a of the polishing member 4 (the direction extending from the winding portion 4a of the polishing member 4) is parallel to the X-axis direction.

[0026] As shown in Figures 4 to 6, the polishing member fixing device 5 has a first block body 30 having a first guide hole 30a, a second block body 31 having a second guide hole 31a, a screw shaft body 32 screwed downward into the first block body 30, a plurality of guide shaft bodies 33 inserted into the first block body 30 and fixed to the second block body 31, and a guide rail 34 disposed in the first guide hole 30a of the first block body 30.

[0027] The first block body 30 is a rectangular parallelepiped member made of metal. The first block body 30 is provided with a first guide hole 30a and a plurality of insertion holes 30b. The first guide hole 30a and the plurality of insertion holes 30b penetrate between a pair of opposing surfaces of the first block body 30 at a right angle in the X-axis direction. The cross-sectional shape of the first guide hole 30a in the up-down direction is an elongated hole extending in the Y-axis direction. The insertion holes 30b are provided on both sides of the first guide hole 30a in the Y-axis direction.

[0028] The first block body 30 has a plurality of first female threads 30c (two in FIG. 4) that are provided downward from the upper surface. Each of the first female threads 30c is located at the center in the Y-axis direction and is provided side by side in the X-axis direction. Each of the first female threads 30c reaches the first guide hole 30a. The screw shaft body 32 is screw-coupled to each of the first female threads 30c.

[0029] The second block body 31 is a rectangular parallelepiped member made of metal, and has the same shape as the first block body 30. The second block body 31 is provided with a second guide hole 31a and a plurality of second internal threads 31b. The second guide hole 31a penetrates between a pair of opposing surfaces of the second block body 31 at a right angle in the X-axis direction. The cross-sectional shape of the second guide hole 31a in the vertical direction is an elongated hole extending in the Y-axis direction, and is the same as the cross-sectional shape of the first guide hole 30a in the vertical direction. The second internal threads 31b are provided in the X-axis direction from the surface opposing the first block body 30. The second internal threads 31b are provided on both sides of the second guide hole 31a in the Y-axis direction. When the first block body 30 and the second block body 31 are butted against each other in the X-axis direction, the positions of the first guide hole 30a and the second guide hole 31a in the vertical direction and the Y-axis direction match. Similarly, in the butted state, the positions of the insertion hole 30b and the second internal threads 31b in the vertical direction and the Y-axis direction match.

[0030] The guide shaft body 33 is a bolt having a head 33a. The guide shaft body 33 is screwed into the second female thread 31b of the second block body 31. A coil spring 35, which is an elastic member, is attached to the guide shaft body 33. The guide shaft body 33 is inserted into the insertion hole 30b of the first block body 30, and its tip portion is screwed into the second female thread 31b of the second block body 31. In this screwed-in state, the first block body 30 is supported so as to be slidable along the length direction (X-axis direction) of the guide shaft body 33 relative to the second block body 31 (see FIG. 8). In addition, in this screwed-in state, the coil spring 35 is compressed between the head 33a of the guide shaft body 33 and the first block body 30. The first block body 30 is urged toward the second block body 31 along the length direction (X-axis direction) of the guide shaft body 33 by the elastic restoring force of the compressed coil spring 35 (see FIG. 4).

[0031] The guide rail 34 is formed by bending a metal plate. The guide rail 34 has a band-shaped base plate portion 34a extending along the X-axis direction, guide plate portions 34b rising from both edges of the base plate portion 34a, and flange portions 34c extending outward in the Y-axis direction from the upper end edges of each guide plate portion 34b. The length of the guide rail 34 is the same as the length of the first guide hole 30a of the first block body 30. With the first extension portion 4b and the second extension portion 4c of the polishing member 4 overlapping each other in the vertical direction, each guide plate portion 34b, 34b restricts movement of the polishing member 4 in a direction perpendicular to the direction extending from the winding portion 4a (Y-axis direction).

[0032] As shown in FIG. 5, the distance L between the outer edges of the flanges 34c in the Y-axis direction is equal to or slightly smaller than the opening width W in the Y-axis direction of the first guide hole 30a of the first block body 30. The guide rail 34 is disposed inside the first guide hole 30a of the first block body 30. The screw shaft body 32 is screwed into the first female thread 30c of the first block body 30, and the first extension portion 4b and the second extension portion 4c of the polishing member 4 are fixed on the base plate portion 34a of the guide rail 34 by the screw shaft body 32 in a state where they overlap each other in the vertical direction. When the guide rail 34 is disposed inside the first guide hole 30a, the inner surfaces on both sides of the first guide hole 30a (the inner surfaces on both sides in the Y-axis direction) restrict the movement of the guide rail 34 in the X-axis direction.

[0033] The lapping device 1 of the present invention is configured as described above. Next, a method of using this lapping device 1 will be described. First, the camshaft 20 is attached to the rotating device 3 on the table 2. At this time, the camshaft 20 is clamped via a center hole (not shown) by the center (or chuck) of the spindle 7 of the headstock 8 and the center of the tailstock 9 so that the axis C of the camshaft 20 coincides with the Y axis (or one end of the camshaft 20 is chucked by the chuck at the outer periphery of the journal, and the other end is pressed and held by the center).

[0034] Next, the polishing member fixture 5 is placed on the slide base 10 of the holding device 6. The polishing member fixture 5 is arranged with the first block body 30 and the second block body 31 aligned in the X-axis direction. The first block body 30 is located on the camshaft 20 side. Also, the first block body 30 is in contact with the second block body 31 due to the elastic restoring force of the coil spring 35. In this state, only the second block body 31 is pressed against the slide base 10 by the bolts 13 of the fixing plate 12, and the second block body 31 of the polishing member fixture 5 is fixed to the holding device 6.

[0035] Next, the servo motor 2b moves the slide table 10 of the holding device 6 in the Y-axis direction to align the cam portion 22 of the camshaft 20 to be polished with the base portion 34a of the guide rail 34 of the polishing member fixture 5 in the Y-axis direction. Next, the camshaft 20 is rotated to position the non-circular portion 22b of the outer periphery of the cam portion 22 to be polished on the polishing member fixture 5 side, and position the circular portion 22a on the opposite side to the polishing member fixture 5 (see FIG. 7). Here, the circular portion 22a of the outer periphery of the cam portion 22 means a portion of the outer periphery of the cam portion 22 that includes a circumferential range in which the distance from the axis C to the outer periphery of the cross section perpendicular to the axis C of the camshaft 20 is constant. Moreover, the non-circular portion 22b of the outer periphery of the cam portion 22 means a portion of the outer periphery of the cam portion 22 other than the circular portion 22a.

[0036] Next, the polishing member 4 is wound around the outer periphery of the cam portion 22 to be polished. Then, of the polishing member 4, the first extension portion 4b on the upper side and the second extension portion 4c on the lower side extending from the wound portion 4a are pulled toward the polishing member fixture 5 along a direction away from the axis C of the camshaft 20. Furthermore, the first extension portion 4b and the second extension portion 4c are guided into the first guide hole 30a of the first block body 30 and the second guide hole 31a of the second block body 31, and passed through them in this order. At this time, the first extension portion 4b and the second extension portion 4c are placed in a mutually overlapping state on the base portion 34a of the guide rail 34 arranged in the first guide hole 30a.

[0037] Thereafter, the threaded shaft body 32 is screwed into the first female thread 30c of the first block body 30 by a tool or the like. As shown in FIG. 5, the threaded shaft body 32 presses the first extension portion 4b and the second extension portion 4c against the base plate portion 34a of the guide rail 34, and is fixed to the polishing member fixing device 5 in a state in which the first extension portion 4b and the second extension portion 4c overlap each other. This fixation applies a predetermined tension to the polishing member 4 wound around the outer periphery of the cam portion 22. In order to apply the predetermined tension, the servo motor 10b may move the holding base 11 in the X-axis direction relative to the slide base 10 in a direction away from the axis C of the camshaft 20, as necessary.

[0038] With a predetermined tension applied to the polishing member 4, the main shaft 7 of the rotating device 3 is rotated at a predetermined rotation speed (for example, about 70 to 90 revolutions per minute) by a servo motor (not shown) to rotate the camshaft 20. When the camshaft 20 is rotated, for example, the non-circular portion 22b of the cam portion 22 is displaced from a state in which it is located on the upper side (see FIG. 3) to a state in which it is located on the opposite side of the polishing member fixing tool 5 with respect to the axis C of the camshaft 20 (see FIG. 8). Due to this displacement, the length of the winding portion 4a of the polishing member 4 increases, and the first extension portion 4b and the second extension portion 4c are pulled. The first extension portion 4b and the second extension portion 4c are fixed to the first block body 30 of the polishing member fixing tool 5. Therefore, the first block body 30 slides along the guide shaft body 33 in a direction approaching the axis C of the camshaft 20 in the X-axis direction relative to the second block body 31.

[0039] Here, the first block body 30 is biased toward the second block body 31 in a direction away from the axis C of the camshaft 20 by the elastic restoring force of the coil spring 35. The biased first block body 30 keeps the polishing member 4 pulled in a direction away from the axis C of the camshaft 20 in the Y-axis direction, and the outer periphery including the non-circular portion 22b of the cam portion 22 is polished by the polishing member 4. After the outer periphery of the cam portion 22 is polished, the holder 11 is moved in a direction approaching the axis C of the camshaft 20 to loosen the polishing member 4. Next, the screw shaft body 32 is loosened, and the polishing member 4 on the guide rail 34 of the first block body 30 is removed from the polishing member fixture 5. Furthermore, if necessary, the outer periphery of the cam portion 22 of the camshaft 20 is polished with the polishing member 4 having finer abrasive grains.

[0040] Next, the slide table 10 is moved in the X direction to align the other cam portion 22 to be polished of the camshaft 20 with the base plate portion 34a of the guide rail 34 of the polishing member fixture 5 in the Y axis direction. Thereafter, the outer periphery of the other cam portion 22 is polished by the polishing member 4 based on the above-mentioned method of use.

[0041] In the manner described above, the lapping device 1 is used, and the outer periphery of the cam portion 22 of the camshaft 20 is polished by the polishing member 4.

[0042] In the lapping device 1, an example has been described in which the outer periphery of the cam portion 22 of the camshaft 20 having a plurality of cam portions 22 on the shaft portion 21 is polished, but the outer periphery of the shaft portion 21 between the cam portions 22 of the camshaft 20 can also be polished. In this case, the slide table 10 of the holding device 6 is moved in the Y-axis direction to align the shaft portion 21 between the cam portions 22 to be polished with the guide rail 34 of the polishing member fixture 5 in the Y-axis direction, and then polishing is performed by the polishing method described above.

[0043] In the lapping device 1 of this embodiment, the polishing member 4 is wound around the outer periphery of the cam portion 22 of the camshaft 20 in the circumferential direction. The wound portion 4a of the polishing member 4 makes it possible to increase the polishing area in the circumferential direction for the outer periphery of the cam portion 22. Therefore, when polishing the outer periphery of the cam portion 22 to a highly accurate finished surface, the processing time required for polishing can be effectively shortened.

[0044] Furthermore, the lapping device 1 winds the polishing member 4 around the outer periphery of the cam portion 22, and passes the first extension portion 4b and the second extension portion 4c extending from the wound portion 4a of the polishing member 4 through the first guide hole 30a and the second guide hole 31a. As a result, the first extension portion 4b and the second extension portion 4c are guided onto the guide rail 34 in a state where they overlap each other in the vertical direction, facilitating preparation for polishing.

[0045] Furthermore, the first extending portion 4b and the second extending portion 4c of the grinding member 4 are restricted from moving in a direction perpendicular to the direction in which the grinding member 4 extends from the wound portion 4a by the guide plate portion 34b of the guide rail 34. This prevents the grinding member 4 from vibrating in the Y-axis direction relative to the outer periphery of the cam portion 22.

[0046] In addition, in the lapping device 1, the first block body 30 of the polishing member fixture 5 slides relative to the second block body 31 via the guide shaft body 33 in the direction extending from the wound portion 4a of the polishing member 4 (X-axis direction). The first block body 30 is biased relative to the second block body 31 in a direction away from the axis C of the camshaft 20 by the elastic restoring force of the coil spring 35 attached to the guide shaft body 33. Therefore, as the non-circular portion 22b of the cam portion 22 rotates, the first block body 30 can slide relative to the second block body 31 while maintaining a predetermined tension relative to the polishing member 4. As a result, it is possible to prevent the polishing member 4 from loosening or breaking during polishing.

[0047] Furthermore, the sliding length of the first block body 30 relative to the second block body 31 that occurs during grinding varies depending on the shape of the non-circular portion of the cam portion 22 of the camshaft 20. For this reason, the length of the guide shaft body 33 can be changed depending on the shape of the non-circular portion of the cam portion 22 to be ground. By changing the length of the guide shaft body 33, the sliding length of the first block body 30 relative to the second block body 31 that occurs during grinding can be ensured.

[0048] In the above embodiment, the guide rail 34 has been described as having one base plate portion 34a as an example, but for example, as shown in Figure 9, a guide rail 36 can be used in which two base plate portions 34a are arranged in the Y-axis direction along the axis C of the camshaft 20.

[0049] The guide rail 36 has two base plate portions 34a, guide plate portions 34b rising from both edges of each base plate portion 34a, a connecting plate portion 34d connecting adjacent guide plate portions 34b located on the inside in the Y axis direction, and a flange portion 34c extending outward in the Y axis direction from the upper edge portions of the guide plate portions 34b located on the outside in the Y axis direction. Here, the interval in the Y axis direction between the base plate portions 34a is the same as the distance in the Y axis direction between adjacent cam portions 22 of the camshaft 20 to be polished.

[0050] In the lapping device 1 equipped with the guide rail 36, the polishing member 4 is wound around each of the outer peripheries of two adjacent cam portions 22 of the camshaft 20, and a first extension portion 4b and a second extension portion 4c extending from the wound portion 4a are fixed by the screw shaft body 32 on two base plate portions 34a of the guide rail 36. In this state, the outer peripheries of the adjacent cam portions 22 of the camshaft 20 to be polished can be polished by a polishing method similar to that of the above-mentioned lapping device 1. [Explanation of symbols]

[0051] 1 Wrapping device 2 Tables 3 Rotating Equipment 4. Abrasive material 4a Winding part 4b First extension part 4c Second extension part 5. Abrasive material fixture 6 Holding equipment 7 Spindle 8 Headstock 9 Tailstock 10 Slide stand 11 Holding stand 12 Fixing plate 13 Volts 20 Camshaft 21 Shaft 22 Cam section 22a Circular section 22b Non-circular part 30 First Block 30a First guide hole 30c First female thread 31 Second Block 31a Second guide hole 31b Second female thread 32 Screw shaft body 33 Guide shaft body 34, 36 Guide rail 34a Substrate section 34b Guide plate part 34d Connecting plate part 35 Coil spring C axis center W Opening Width L distance

Claims

1. A lapping device for polishing an outer periphery of a cam portion or an outer periphery of a shaft portion of a camshaft having a plurality of cam portions fixed to the shaft portion, comprising: a rotating device that rotates the camshaft around an axis of the camshaft; a tape-like polishing member wound around an outer periphery of the cam portion or an outer periphery of the shaft portion of the camshaft in a circumferential direction; a polishing member fixing device that fixes a first extension portion and a second extension portion of the polishing member extending from a wrapping portion that is wrapped around the outer periphery of the cam portion or the outer periphery of the shaft portion.

2. 2. The lapping apparatus according to claim 1, wherein the polishing member fixing device has a guide hole that guides the first extension portion and the second extension portion of the polishing member in a direction extending from the winding portion, and the first extension portion and the second extension portion of the polishing member are fixed to the polishing member fixing device in a mutually overlapping state.

3. the polishing member fixture has a guide rail disposed inside the guide hole, the first extension portion and the second extension portion of the polishing member are fixed on the guide rail in a mutually overlapping state; 3. The lapping device according to claim 2, wherein the guide rail has a plurality of guide plate portions that restrict movement of the polishing member relative to the first and second extending portions in a direction perpendicular to a direction in which the polishing member extends from the winding portion.

4. 4. The lapping device according to claim 1, wherein the abrasive member fixture is biased in a direction away from the axis of the camshaft along a direction extending from the wound portion of the abrasive member.

5. The camshaft further includes a holding device provided at a position away from an axis of the camshaft, the polishing member fixing device has a first block body for fixing the first extension portion and the second extension portion of the polishing member, a second block body fixed to the holding device, and a guide shaft body for supporting the first block body slidably relative to the second block body along a direction extending from the wound portion of the polishing member, 4. The wrapping apparatus according to claim 1, wherein the first blocking body is biased toward the second blocking body.

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