Processing equipment

Abstract

The present invention provides a machining apparatus that, in both double-ended and cantilevered configurations, can sufficiently suppress the vibration of the grinding wheel along the radial direction when it comes into contact with the workpiece, thereby improving the dimensional accuracy of the workpiece. [Solution] The processing apparatus 10 comprises a rotating shaft 20 rotatably supported by a housing 16, a rotating tool 12 detachably mounted on the rotating shaft 20, an attachment 40, and a bracket 50. The rotating tool 12 has a front end surface 300 facing a first direction along the axial direction of the rotating shaft 20, and a rear end surface 302 facing a second direction opposite to the first direction. The attachment 40 is detachably connected to the front end surface 300 of the rotating tool 12. The bracket 50 rotatably supports the attachment 40 when it is supported by the housing 16.

Description

Technical Field

[0001] The present disclosure relates to a processing apparatus.

Background Art

[0002] As one type of processing apparatus, a grinding apparatus is known. The grinding wheel of a grinding apparatus for gears has a spiral grinding portion on its side surface. The tooth surface of the gear is ground by this grinding portion.

[0003] In the configuration disclosed in Japanese Patent Application Laid-Open No. 2021-79475, both axial ends of the rotating shaft are supported by predetermined support members. That is, the support for the rotating shaft is so-called both-end support. On the other hand, Japanese Patent Application Laid-Open No. 5-208314 shows a configuration in which one axial end of the rotating shaft is supported by a rotating motor. In this case, the grinding wheel is detachably attached to the other axial end of the rotating shaft. Therefore, the support of the rotating shaft is so-called cantilever support.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In both the both-end support and the cantilever support, when the workpiece contacts the grinding wheel, the grinding wheel may vibrate along the radial direction. If the vibration cannot be sufficiently suppressed, in other words, if the amplitude of the vibration is large, there is a concern that the dimensional accuracy of the workpiece will decrease.

[0006] The present disclosure aims to solve the above-described problems.

Means for Solving the Problems

[0007] Aspects of the present disclosure are machining apparatus comprising a rotary shaft rotatably supported in a housing and a cylindrical rotary tool detachably mounted on the rotary shaft, wherein the rotary shaft has a protruding end that protrudes from the housing in a first direction along the axial direction of the rotary shaft and on which the rotary tool is mounted, the rotary tool has a front end face formed at the end of the rotary tool in the first direction and facing the first direction, and a rear end face formed at the end of the rotary tool in a second direction opposite to the first direction and facing the second direction, and the machining apparatus comprises an attachment detachably connected to the front end face of the rotary tool and a bracket supported by the housing and rotatably supporting the attachment. [Effects of the Invention]

[0008] According to this disclosure, radial vibration of the rotary tool is suppressed. Therefore, the dimensional accuracy of the processed product can be improved. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a side cross-sectional view of the main part of a processing apparatus (grinding apparatus) according to an embodiment of this disclosure. [Figure 2] Figure 2 is a schematic diagram illustrating the configuration of an electroplated grinding wheel. [Figure 3] Figure 3 is a close-up view of the main part showing the grinding process being performed on the teeth of a gear using a grinding wheel. [Modes for carrying out the invention]

[0010] In the embodiments described below, we illustrate an example in which the processing apparatus 10 shown in Figure 1 is a grinding apparatus 10A for grinding the teeth T of the gear G shown in Figure 3. In this case, the rotating tool 12 shown in Figure 1 is a grinding wheel 30. However, the processing apparatus 10 is not limited to a grinding apparatus 10A. The processing apparatus 10 may be an apparatus that performs processing other than grinding. Therefore, the rotating tool 12 is not limited to a grinding wheel 30. Also, the grinding apparatus 10A is not limited to a gear grinding apparatus. The grinding apparatus 10A may be an apparatus for grinding other workpieces.

[0011] Furthermore, in the following, when simply referred to as "axial direction," "axial direction" means "the axial direction of the rotating shaft 20." The axial direction of the rotating shaft 20 refers to the direction parallel to the central axis L of the rotating shaft 20. In addition, "the direction along the radial direction of the rotating shaft 20" may also be simply referred to as "radial direction." Note that the radial direction of the rotating shaft 20 coincides with the radial direction of the grinding wheel 30. Therefore, "radial direction" may also mean "the direction along the radial direction of the grinding wheel 30."

[0012] Figure 1 is a side cross-sectional view of the main part of the grinding device 10A. The grinding device 10A comprises a housing 16 and a rotating shaft 20 rotatably supported by the housing 16. The viewpoint in Figure 1 is the radial direction perpendicular to the central axis L (or axial direction) of the rotating shaft 20.

[0013] The rotating shaft 20 has a shaft body 200 and a holder portion 210. The shaft body 200 is housed in a shaft hole 100 formed in the housing 16. A housing-side bearing 110 is interposed between the side surface of the shaft body 200 and the inner surface of the shaft hole 100. The housing-side bearing 110 is, for example, a ball bearing, but is not limited to a ball bearing.

[0014] The direction along the axial axis, from the inside to the outside of the housing 16 (from the shaft body 200 to the holder portion 210), is referred to as the first direction. The direction opposite to the first direction is referred to as the second direction. In the shaft body 200, a fitting recess 204 is formed at the first end 202 facing the first direction, recessed toward the second direction. In the shaft body 200, the second end (not shown) facing the second direction is connected to the output shaft of a rotary motor (not shown). As the rotary motor is driven and the output shaft rotates, the rotary shaft 20 rotates about the central axis L.

[0015] The holder portion 210 has a flange portion 212, a fitting projection 214, and a columnar projection 216. The flange portion 212 has a mounting hole 218 that forms the first connecting portion 230. The fitting projection 214 extends from the end face of the flange portion 212 facing the second direction toward the second direction. The columnar projection 216 extends from the end face of the flange portion 212 facing the first direction toward the first direction. In the columnar projection 216, the portion located in the first insertion hole 316 is a tapered portion 220 that tapers in diameter from the second direction toward the first direction.

[0016] The fitting projection 214 is fitted into the fitting recess 204 of the shaft body 200. Furthermore, the holder portion 210 and the first end portion 202 of the shaft body 200 are connected by a bolt (not shown). In this state, the flange portion 212 and the columnar projection 216 are located outside the housing 16 (outside the shaft hole 100). Therefore, the end of the rotating shaft 20 facing the first direction protrudes from the housing 16 (shaft hole 100). Hereinafter, this end portion will be referred to as the "protruding end portion 22".

[0017] The grinding wheel 30 is detachably attached to the holder portion 210. In a preferred embodiment, the grinding wheel 30 is an electrodeposited grinding wheel 30A. As shown in FIG. 2, the electrodeposited grinding wheel 30A has a substrate 32 made of a metal material and abrasive grains 34. The abrasive grains 34 are, for example, diamond abrasive grains. The abrasive grains 34 are fixed to the outer surface of the substrate 32 by a plating layer 36 (electrodeposited layer). In this embodiment, it is easy to provide the connecting hole 342 (described later) shown in FIG. 1 in the grinding wheel 30 by machining. This is because since the substrate 32 (see FIG. 2) is a metal material, it is easy to perform various machining on the substrate 32.

[0018] However, the grinding wheel 30 is not limited to the electrodeposited grinding wheel 30A. The grinding wheel 30 may be a sintered grinding wheel in which abrasive grains 34 (for example, diamond abrasive grains) are sintered.

[0019] As shown in FIG. 1, the grinding wheel 30 has a hollow cylindrical main body 313 with both axial ends open and a partition wall portion 314 provided to partition the hollow interior of the cylindrical main body 313. The grinding wheel 30 has a cylindrical shape formed by the cylindrical main body 313 and the partition wall portion 314. The cylindrical main body 313 is an outer peripheral portion located on the outer peripheral side of the partition wall portion 314, and the partition wall portion 314 is an inner peripheral portion located on the inner peripheral side of the cylindrical main body 313.

[0020] The cylindrical main body 313 has a front end face 300, a rear end face 302, and an outer peripheral face 304. The front end face 300 is the bottom face of the grinding wheel 30 facing the first direction. The rear end face 302 is the bottom face of the grinding wheel 30 facing the second direction. The grinding wheel 30 has a front concave portion 310 recessed from the front end face 300 toward the rear end face 302. Therefore, when the grinding wheel 30 is viewed from the axial direction, the front end face 300 has an annular shape (see FIG. 3). The grinding wheel 30 has a rear concave portion 312 recessed from the rear end face 302 toward the front end face 300. Therefore, when the grinding wheel 30 is viewed from the axial direction, the rear end face 302 has an annular shape similar to the front end face 300. In the illustrated example, the inner diameter of the rear concave portion 312 is larger than the inner diameter of the front concave portion 310.

[0021] The hollow interior of the cylindrical body 313 is divided by a partition wall portion 314 into a front recess 310 and a rear recess 312. The partition wall portion 314 has a first insertion hole 316 and a second insertion hole 318. The first insertion hole 316 and the second insertion hole 318 extend along the axial direction of the rotary shaft 20 and penetrate the partition wall portion 314.

[0022] The first insertion hole 316 is formed in the partition wall portion 314 at a portion through which the central axis L of the rotary shaft 20 passes. The central axis L of the rotary shaft 20 and the central axis of the first insertion hole 316 are aligned. The columnar protrusion 216 of the protruding end portion 22 is passed through the first insertion hole 316. The tapered portion 220 of the columnar protrusion 216 is located in the first insertion hole 316. Therefore, the first insertion hole 316 is a tapered hole corresponding to the shape of the tapered portion 220. The end portion of the columnar protrusion 216 in the first direction is located within the front recess 310.

[0023] The second insertion hole 318 is formed radially outside the central axis L of the rotary shaft 20. The second insertion hole 318 forms a first coupling portion 230 together with the mounting hole 218 and the mounting tool 330. Specifically, the flange portion 212 of the protruding end portion 22 is inserted into the rear recess 312. With the second insertion hole 318 and the mounting hole 218 aligned, the mounting tool 330 is passed through the second insertion hole 318. The mounting tool 330 is, for example, a mounting bolt 332. In this case, a threaded portion (not shown) is formed on the inner surface of the mounting hole 218. As the mounting bolt 332 is screwed into the threaded portion, the grinding wheel 30 is coupled to the rotary shaft 20 by the first coupling portion 230. As can be understood from this, the support of the grinding wheel 30 on the rotary shaft 20 is a cantilever support.

[0024] In order to firmly couple the rotary shaft 20 and the grinding wheel 30, it is preferable to provide a plurality of first coupling portions 230 on the rotary shaft 20 and the grinding wheel 30. However, if the relative rotation between the rotary shaft 20 and the grinding wheel 30 can be sufficiently suppressed by one first coupling portion 230, the first coupling portion 230 may be one.

[0025] An annular groove 320 is formed on the rear end surface 302 of the grinding wheel 30. On the other hand, an annular projection 104 is provided on the front end surface 102 of the housing 16 facing the first direction. The annular projection 104 is inserted into the annular groove 320. This prevents foreign matter (such as grinding fluid) from entering the rear recess 312 through the space between the rear end surface 302 of the grinding wheel 30 and the front end surface 102 of the housing 16. The annular projection 104 may be spaced apart from the inner surface of the annular groove 320. However, the annular projection 104 may slide against the inner surface of the annular groove 320 when the grinding wheel 30 rotates.

[0026] The grinding wheel 30 has a connecting hole 342 that forms a second connecting portion 340. The connecting hole 342 is formed on the front end surface 300 of the grinding wheel 30. A connector 430 for detachably connecting the attachment 40 (described later) is inserted into the connecting hole 342. The connector 430 is, for example, a connecting bolt 432. In this case, a threaded portion is provided on the inner surface of the connecting hole 342. The second connecting portion 340 is located on the first direction side of the first connecting portion 230.

[0027] The grinding wheel 30 has a grinding portion 306 on its outer surface 304. In an embodiment where the processing device 10 is a grinding device 10A, the grinding portion 306 has a helical shape.

[0028] The grinding device 10A further comprises an attachment 40. The attachment 40 has a substantially disc-shaped base 400. Hereinafter, the end face of the base 400 facing the first direction will be referred to as the "main surface 402", and the end face of the base 400 facing the second direction will be referred to as the "back surface 404". The back surface 404 faces the front end surface 300 of the grinding wheel 30.

[0029] The base portion 400 has a stepped hole 406. The stepped hole 406, together with the connector 430, forms a second connecting portion 340. Specifically, the stepped hole 406 is formed in the base portion 400 at a location avoiding the main surface side protrusion 408 and the back side protrusion 410, and extends axially to penetrate the base portion 400. The body of the connecting bolt 432, which serves as the connector 430, passes through the stepped hole 406. The connecting bolt 432 is screwed into the threaded portion of the connecting hole 342 of the grinding wheel 30. As a result, the attachment 40 is connected to the front end surface 300 of the grinding wheel 30 by the second connecting portion 340. The head of the connecting bolt 432 is housed in the stepped hole 406. By loosening the connecting bolt 432 relative to the connecting hole 342, the attachment 40 is removed from the grinding wheel 30. Thus, the attachment 40 is detachable from the grinding wheel 30.

[0030] To securely connect the grinding wheel 30 and the attachment 40, it is preferable to provide a plurality of second connecting portions 340 on the grinding wheel 30 and the attachment 40. In one embodiment, the plurality of second connecting portions 340 are provided radially outward from the plurality of first connecting portions 230. In this case, radial vibration of the grinding wheel 30 can be sufficiently suppressed. Alternatively, the plurality of second connecting portions 340 may be provided radially inward from the plurality of first connecting portions 230. Or, some of the plurality of second connecting portions 340 may be provided radially outward from some of the plurality of first connecting portions 230, and the remaining plurality of second connecting portions 340 may be provided radially inward from the remaining plurality of first connecting portions 230.

[0031] However, if a single second coupling portion 340 can suppress the relative rotation between the attachment 40 and the grinding wheel 30, then only one second coupling portion 340 is necessary. In this embodiment as well, it is preferable to provide the second coupling portion 340 radially outward from the first coupling portion 230, but this is not essential.

[0032] A roughly disc-shaped main surface-side projection 408 protrudes from the main surface 402 of the base 400, and a roughly disc-shaped back surface-side projection 410 protrudes from the back surface 404 of the base 400. The projection direction of the main surface-side projection 408 is the first direction, and the projection direction of the back surface-side projection 410 is the second direction. The diameter of the back surface-side projection 410 is larger than the diameter of the main surface-side projection 408.

[0033] The rear projection 410 engages with the front recess 310 of the grinding wheel 30. The side surface of the rear projection 410 abuts against, for example, the inner circumferential surface of the front recess 310. However, it is not essential that the side surface of the rear projection 410 abuts against the inner circumferential surface of the front recess 310. A relief recess 412 is formed in the center of the rear projection 410. The relief recess 412 prevents the rear projection 410 from interfering with the columnar projection 216.

[0034] The attachment 40 further includes an auxiliary rotating shaft portion 420. The auxiliary rotating shaft portion 420 extends from the main surface side convex portion 408 so as to protrude along a first direction. The auxiliary rotating shaft portion 420 and the rotating shaft 20 are centered relative to each other. Therefore, when the grinding device 10A is viewed from the axial direction of the rotating shaft 20, the central axis M of the auxiliary rotating shaft portion 420 and the central axis L of the rotating shaft 20 substantially overlap each other. In other words, the amount of misalignment between the central axis M of the auxiliary rotating shaft portion 420 and the central axis L of the rotating shaft 20 is within an acceptable range.

[0035] The auxiliary rotating shaft portion 420 has a tapered portion 422 that gradually tapers in diameter from the second direction to the first direction, and an equal-diameter portion 424 with a constant diameter. The tapered portion 422 is closer to the base portion 400 than the equal-diameter portion 424. A threaded portion 426 is provided on the side surface of the auxiliary rotating shaft portion 420.

[0036] As described above, the rotating shaft 20 and the grinding wheel 30 are connected by the first connecting part 230, and the grinding wheel 30 and the attachment 40 are connected via the second connecting part 340. Therefore, when the rotating shaft 20 rotates, the grinding wheel 30 and the attachment 40 rotate together with the rotating shaft 20.

[0037] The grinding device 10A further includes a bracket 50. In the bracket 50, one end of the rotating shaft 20 in the radial direction is supported by the housing 16. In other words, the bracket 50 is firmly positioned and fixed to the housing 16. This prevents the bracket 50 from vibrating.

[0038] Bracket 50 has an insertion hole 500 that extends along the axial direction of the rotating shaft 20. A bracket-side bearing 502 (bearing) is provided within the insertion hole 500. The auxiliary rotating shaft portion 420 of the attachment 40 is inserted into the insertion hole 500 and passed through the bracket-side bearing 502. Therefore, the bracket-side bearing 502 is interposed between the side surface of the auxiliary rotating shaft portion 420 and the inner surface of the insertion hole 500. This allows the attachment 40 to be rotatably supported by the bracket 50. The bracket-side bearing 502 is located on the tapered portion 422 of the auxiliary rotating shaft portion 420.

[0039] In the illustrated example, the bracket-side bearing 502 is a cylindrical roller bearing 502A. The cylindrical roller bearing 502A has a large load capacity for loads acting along the radial direction. Therefore, it can sufficiently suppress radial vibration of the auxiliary rotating shaft portion 420. However, the bracket-side bearing 502 is not limited to a cylindrical roller bearing 502A. The bracket-side bearing 502 may be another type of roller bearing, such as a needle roller bearing. Alternatively, the bracket-side bearing 502 may be a ball bearing.

[0040] The grinding device 10A includes a first seal member 510 and a second seal member 512. The first seal member 510 and the second seal member 512 have a so-called labyrinth seal structure. Within the insertion hole 500, the first seal member 510 is positioned closer to the bracket-side bearing 502 in a first direction, and the second seal member 512 is positioned closer to the bracket-side bearing 502 in a second direction. The bracket-side bearing 502 is interposed between the first spacer 524 and the second spacer 526. The first seal member 510 and the second seal member 512 prevent foreign matter from entering the insertion hole 500.

[0041] The grinding device 10A includes a fastener 520. In the illustrated example, the fastener 520 has a nut 522, a first spacer 524, and a second spacer 526. The nut 522 is screwed onto the threaded portion 426. The first end of the first spacer 524 is exposed from the insertion hole 500, and the second end of the first spacer 524 is inserted into the insertion hole 500 and abuts against the first seal member 510. The second spacer 526 is located, for example, outside the insertion hole 500. The first end of the second spacer 526 can abut against the second seal member 512. The second end of the second spacer 526 can abut against the main surface side protrusion 408.

[0042] The manufacturing method for the grinding apparatus 10A configured as described above will now be briefly explained. First, a connecting hole 342 is formed on the front end surface 300 of the grinding wheel 30, which has been removed from the rotating shaft 20, by machining (for example, tapping). If the grinding wheel 30 is an electroplated grinding wheel 30A as shown in Figure 2, the base material 32 is made of metal, so it is easy to machine the grinding wheel 30. If the grinding wheel 30 is a sintered grinding wheel, a molded body having the connecting hole 342 is formed, and then the molded body is sintered.

[0043] Next, as shown in Figure 1, the flange portion 212 of the holder portion 210 is inserted into the rear recess 312 of the grinding wheel 30, and the columnar projection 216 of the holder portion 210 is passed through the first insertion hole 316 of the grinding wheel 30, and the grinding wheel 30 is connected to the holder portion 210 of the rotating shaft 20 by the first connecting portion 230 described above.

[0044] Next, the attachment 40 is connected to the front end surface 300 of the grinding wheel 30 by the second connecting portion 340. Furthermore, the auxiliary rotating shaft portion 420 is passed through the insertion hole 500 of the bracket 50, and the bracket 50 is connected to the housing 16. This securely supports the bracket 50 in the housing 16. At this stage, the nut 522 is temporarily fastened to the threaded portion 426.

[0045] Next, the nut 522 is screwed in to move it in the second direction along the auxiliary rotating shaft portion 420. As the nut 522 is screwed in, it moves in the second direction along the columnar projection portion 216. The nut 522 that has moved in the second direction comes into contact with the first spacer 524. As the nut 522 moves further in the second direction, the first spacer 524 is pushed by the nut 522 and moves in the second direction. As a result, the first seal member 510, the bracket-side bearing 502, the second seal member 512, and the second spacer 526 are pushed by the first spacer 524 and move in the second direction.

[0046] The second spacer 526 stops when it comes into contact with the main surface side protrusion 408. Consequently, the first spacer 524, the first sealing member 510, the bracket side bearing 502, and the second sealing member 512 also stop. If the nut 522 is turned further in this state, the bracket side bearing 502 is tightened by the first spacer 524 and the second spacer 526, which are subjected to load from the nut 522 and the main surface side protrusion 408.

[0047] This tightening tightens the inner ring 504 of the bracket-side bearing 502, causing it to expand slightly radially outward. This reduces the gap between the inner ring 504 and the outer ring 506. In some cases, the gap almost disappears. If the bracket-side bearing 502 is a cylindrical roller bearing 502A, the above tightening improves the radial rigidity of the bracket-side bearing 502.

[0048] Next, the method of using the grinding device 10A will be explained. As shown in Figure 3, the grinding device 10A is used to grind the teeth T of the gear G using the helical grinding portion 306 of the grinding wheel 30.

[0049] To perform grinding, the gear G is held on a driven shaft (not shown) that can be driven to rotate, and the teeth T of the gear G are engaged with the grinding portion 306 of the grinding wheel 30. Next, grinding fluid (not shown) is supplied to the area to be ground, and the rotation motor is energized. As a result, the rotating shaft 20 begins to rotate. Along with this rotation, the grinding wheel 30 and the attachment 40 (see Figure 1) rotate together with the rotating shaft 20.

[0050] Since the first sealing member 510 and the second sealing member 512 are inserted into the insertion hole 500 of the bracket 50, the intrusion of grinding fluid into the insertion hole 500 is suppressed. Also, since the annular projection 104 is inserted into the annular groove 320, the intrusion of grinding fluid into the rear recess 312 from between the rear end surface 302 of the grinding wheel 30 and the front end surface 102 of the housing 16 is prevented. The same applies to foreign matter other than grinding fluid (dust, etc.). Therefore, the bracket-side bearing 502 and the housing-side bearing 110 are protected.

[0051] As described above, the rotating shaft 20 and the auxiliary rotating shaft portion 420 are centered. In this state, the auxiliary rotating shaft portion 420 is supported by the bracket-side bearing 502. Moreover, the bracket 50 is firmly positioned and fixed to the housing 16. Therefore, as shown in Figure 3, when the teeth of the gear G are in sliding contact with the grinding portion 306 of the grinding wheel 30, vibration of the attachment 40 and the grinding wheel 30 along the radial direction is suppressed.

[0052] When the bracket-side bearing 502 is a cylindrical roller bearing 502A, the cylindrical roller bearing 502A has a large load capacity against radial loads. In addition, the gap between the inner ring 504 and the outer ring 506 is almost eliminated by the tightening of the fastener 520. As a result, vibration of the attachment 40 and the grinding wheel 30 along the radial direction is further suppressed.

[0053] For the reasons stated above, it is possible to avoid the formation of minute undulations on the teeth T of the gear G (see Figure 3) due to the vibration of the grinding wheel 30.

[0054] When the grinding wheel 30 is worn out, replace it with a new one. In this case, first remove the bracket 50 shown in Figure 1 from the housing 16 and attachment 40, then remove the attachment 40 from the grinding wheel 30. Next, remove the grinding wheel 30 from the holder portion 210 of the rotating shaft 20. After that, attach the new grinding wheel 30 to the holder portion 210.

[0055] A cylindrical body covering the outer circumference of the grinding wheel 30 and the outer circumference of the attachment 40 may be connected to the housing 16. This cylindrical body has a pivot axis at a position offset from the central axis L of the rotating shaft 20. The bracket 50 is supported by the pivot axis. In this case, the cylindrical body, attachment 40 and bracket 50 are unitized as an assembly. The bracket 50 is supported by the housing 16 via the cylindrical body.

[0056] In this configuration, the bracket 50 and attachment 40 can be rotated integrally by removing the connector 430 (connecting bolt 432) from the connecting hole 342. The pivot point of the bracket 50 and attachment 40 is the pivot axis. This rotation causes the attachment 40 to move away from the grinding wheel 30. Therefore, when replacing the grinding wheel 30, it is not necessary to remove the bracket 50 from the cylindrical body, nor is it necessary to remove the cylindrical body from the housing 16. Thus, the replacement of the grinding wheel 30 is easy.

[0057] This embodiment provides the following effects.

[0058] As shown in Figure 1, the grinding device 10A includes a grinding wheel 30 mounted on a protruding end 22 of a rotating shaft 20. An attachment 40 is mounted on the front end surface 300 of the grinding wheel 30, and this attachment 40 is rotatably supported by a bracket 50 supported by a housing 16.

[0059] With this configuration, vibration of the attachment 40 and grinding wheel 30 along the radial direction is suppressed. As a result, the dimensional accuracy of the gear G (see Figure 3) is improved.

[0060] As shown in Figure 1, the second coupling portion 340 connecting the grinding wheel 30 and the attachment 40 is provided radially outward from the first coupling portion 230 connecting the rotating shaft 20 and the grinding wheel 30. In this case, vibration of the attachment 40 and the grinding wheel 30 along the radial direction is further suppressed compared to the case where the first coupling portion 230 is provided radially outward from the second coupling portion 340.

[0061] The attachment 40 has an auxiliary rotating shaft portion 420. The auxiliary rotating shaft portion 420 and the rotating shaft 20 are centered. The bracket 50 has an insertion hole 500 into which the auxiliary rotating shaft portion 420 is inserted. A bracket-side bearing 502 (bearing) is provided inside the insertion hole 500. With this configuration, the attachment 40 can be rotatably supported on the bracket 50.

[0062] The bracket-side bearing 502 is interposed in the axial direction between the first sealing member 510 and the second sealing member 512. Since the first sealing member 510 and the second sealing member 512 seal the insertion hole 500, foreign matter is prevented from entering the insertion hole 500. Therefore, for example, it is possible to prevent the bracket-side bearing 502 from getting wet with grinding fluid supplied to the machined area during grinding. In other words, the bracket-side bearing 502 is protected from grinding fluid and the like.

[0063] The bracket-side bearing 502 is tightened from both the first and second directions by the fastener 520. This makes the bracket-side bearing 502 less susceptible to radial vibration, thereby further suppressing vibration of the grinding wheel 30.

[0064] The fastener 520 includes a nut 522, a first spacer 524, and a second spacer 526. The bracket-side bearing 502 is interposed axially between the first spacer 524 and the second spacer 526. As the nut 522 is screwed onto the threaded portion 426 of the auxiliary rotating shaft portion 420, the first spacer 524 and the second spacer 526 tighten the bracket-side bearing 502.

[0065] In this way, the bracket-side bearing 502, sandwiched between the first spacer 524 and the second spacer 526, can be easily tightened by the simple operation of screwing the nut 522 onto the threaded portion 426.

[0066] In a preferred embodiment, the bracket-side bearing 502 is a cylindrical roller bearing 502A. The cylindrical roller bearing 502A has a large load capacity against radial loads. As a result, the auxiliary rotating shaft portion 420 supported by the cylindrical roller bearing 502A is less likely to vibrate radially, and thus the radial vibration of the grinding wheel 30 can be further suppressed. In addition, when the cylindrical roller bearing 502A is tightened with the fastener 520, the gap between the inner ring 504 and the outer ring 506 becomes smaller. As a result, the attachment 40 is even less likely to vibrate radially.

[0067] In a preferred embodiment, the grinding wheel 30 is an electroplated grinding wheel 30A having the configuration shown in Figure 2. The electroplated grinding wheel 30A has a base material 32 made of metal. Since the base material 32 is made of metal, it is easy to process the grinding wheel 30 for connection to the attachment 40. For example, it is easy to process the front end surface 300 to form a connecting hole 342. Therefore, it is easy to connect the attachment 40 to an existing grinding wheel 30.

[0068] The grinding wheel 30 has, for example, a helical grinding portion 306 formed on its outer circumferential surface 304. The grinding portion 306 grinds the teeth T of the gear G. In this case, it is possible to avoid the formation of fine undulations on the teeth T of the gear G.

[0069] The following additional information is disclosed regarding the above embodiments.

[0070] (Note 1) The processing apparatus (10) of the present disclosure comprises a rotating shaft (20) rotatably supported in a housing (16) and a cylindrical rotating tool (12) detachably mounted on the rotating shaft, wherein the rotating shaft has a protruding end (22) that protrudes from the housing in a first direction along the axial direction of the rotating shaft and on which the rotating tool is mounted, the rotating tool has a front end surface (300) formed at the end of the rotating tool in the first direction and facing the first direction, and a rear end surface (302) formed at the end of the rotating tool in a second direction opposite to the first direction and facing the second direction, the processing apparatus comprises an attachment (40) detachably connected to the front end surface of the rotating tool and a bracket (50) supported in the housing and rotatably supporting the attachment.

[0071] The attachment and bracket suppress radial vibration of the rotary tool. This improves the dimensional accuracy of the processed product.

[0072] (Note 2) In the processing apparatus described in Appendix 1, the rotating shaft and the rotating tool are connected by a first coupling portion (230), and the rotating tool and the attachment are connected by a second coupling portion (340), and the second coupling portion may be provided on the outside of the first coupling portion in the radial direction of the rotating tool.

[0073] This configuration further suppresses radial vibration of the rotating tool.

[0074] (Note 3) In the processing apparatus described in Appendix 1, the attachment has an auxiliary rotating shaft portion (420) that extends toward the first direction and is centered with the rotating shaft, and the bracket may have an insertion hole (500) into which the auxiliary rotating shaft portion is inserted, and a bearing (502) interposed between the side surface of the auxiliary rotating shaft portion and the inner surface of the insertion hole.

[0075] This configuration allows the attachment to be rotatably supported by the bracket.

[0076] (Note 4) In the processing apparatus described in Appendix 3, a first seal member (510) and a second seal member (512) are provided, and the bearing may be interposed between the first seal member and the second seal member in the axial direction.

[0077] The insertion hole is sealed by the first and second sealing members. Therefore, the entry of foreign matter into the insertion hole is prevented. This prevents the bearing from getting wet with, for example, a cooling liquid (e.g., grinding fluid) supplied to the workpiece during machining.

[0078] (Note 5) In the processing apparatus described in Appendix 3 or 4, a clamping device (520) capable of tightening the bearing from both the first and second directions may be provided.

[0079] As the clamping device tightens the bearing, the bearing becomes less prone to radial vibration. Therefore, vibration of the rotating tool can be further suppressed.

[0080] (Note 6) In the processing apparatus described in Appendix 5, the fastener comprises a nut (522), a first spacer (524), and a second spacer (526), ​​the bearing is interposed between the first spacer and the second spacer in the axial direction, and the auxiliary rotating shaft portion has a threaded portion (426) on its side surface, and the first spacer and the second spacer may tighten the bearing as the nut is screwed onto the threaded portion.

[0081] In this case, the bearing sandwiched between the first and second spacers can be easily tightened by the simple operation of screwing the nut onto the threaded portion.

[0082] (Note 7) In the processing apparatus described in any one of the appendices 3 to 6, the bearing may be a cylindrical roller bearing (502A).

[0083] Cylindrical roller bearings have a high load capacity against radial loads. Therefore, the attachment is less prone to radial vibration, further suppressing radial vibration of the rotating tool. Furthermore, when a cylindrical roller bearing is tightened with a clamp, the gap between the inner and outer rings of the bearing becomes smaller. This further reduces radial vibration of the attachment.

[0084] (Note 8) In the processing apparatus described in any one of the appendices 1 to 7, the rotating tool may be a grinding wheel (30), and the processing apparatus may be a grinding device (10A).

[0085] In this case, radial vibration of the grinding wheel during grinding is suppressed. Consequently, the dimensional accuracy of the product obtained by grinding is improved.

[0086] (Note 9) In the processing apparatus described in Appendix 8, the grinding wheel may have a base material (32) made of a metal material and abrasive grains (34) fixed to the outer surface of the base material.

[0087] Since the base material is metal, it is easy to process the grinding wheel for connection to an attachment. For example, tapping can be easily performed on the front end surface of the grinding wheel.

[0088] (Note 10) In the processing apparatus described in Appendix 8 or 9, the grinding wheel has a helical grinding portion (306) formed on the outer peripheral surface (304) located between the front end surface and the rear end surface, and the grinding portion may grind the teeth (T) of the gear (G).

[0089] This prevents the formation of minute undulations in the gear teeth.

[0090] While this disclosure has been described in detail, it is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of this disclosure or from the intent of this disclosure derived from the claims and their equivalents. These embodiments can also be implemented in combination. For example, the order of operations and processes in the embodiments described above are given as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above. [Explanation of Symbols]

[0091] 10... Processing equipment 10A... Grinding equipment 12…Rotating tool 16…Housing 20... Rotating shaft 22... Protruding end 30...Grinding wheel 30A...Electroplated grinding wheel 32...Base material 34...Abrasive grains 40...Attachment 50...Bracket 210...Holder part 216...Columnar projection 230...First joint part 300...Front end surface 302...Rear end face 306...Grinding section 340...Second joint section 420...Auxiliary rotating shaft section 500…Insertion hole 502…Bracket-side bearing (bearing) 502A...Cylindrical roller bearing 510...First seal member 512...Second sealing member 520...Fastener G... Gear

Claims

1. A machining apparatus comprising a rotating shaft rotatably supported in a housing, and a cylindrical rotating tool detachably mounted on the rotating shaft, The rotating shaft has a protruding end that extends out of the housing in a first direction along the axial direction of the rotating shaft and on which the rotating tool is mounted. The rotating tool has a front end surface formed at the end of the rotating tool in the first direction and facing the first direction, and a rear end surface formed at the end of the rotating tool in the second direction opposite to the first direction and facing the second direction. The aforementioned processing apparatus is An attachment detachably connected to the front end surface of the rotary tool, A bracket supported by the housing and rotatably supporting the attachment, A processing device equipped with the following features.

2. In the processing apparatus according to claim 1, the rotating shaft and the rotating tool are connected by a first coupling portion, The rotary tool and the attachment are connected by a second coupling portion. A machining apparatus in which, in the radial direction of the rotating tool, the second coupling portion is provided outside the first coupling portion.

3. In the processing apparatus according to claim 1, the attachment has an auxiliary rotating shaft portion that extends toward the first direction and is centered with the rotating shaft, The bracket is a processing device having an insertion hole into which the auxiliary rotating shaft portion is inserted, and a bearing interposed between the side surface of the auxiliary rotating shaft portion and the inner surface of the insertion hole.

4. A processing apparatus according to claim 3, comprising a first seal member and a second seal member, wherein the bearing is interposed between the first seal member and the second seal member in the axial direction.

5. A processing apparatus according to claim 3, comprising a fastener capable of tightening the bearing from both the first and second directions.

6. In the processing apparatus according to claim 5, the fastener comprises a nut, a first spacer and a second spacer, and the bearing is interposed between the first spacer and the second spacer in the axial direction. The aforementioned auxiliary rotating shaft portion has a threaded portion on its side, A processing device wherein the first spacer and the second spacer tighten the bearing as the nut is screwed onto the threaded portion.

7. A processing apparatus according to any one of claims 3 to 6, wherein the bearing is a cylindrical roller bearing.

8. A processing apparatus according to claim 1, wherein the rotating tool is a grinding wheel, and the processing apparatus is a grinding apparatus.

9. The processing apparatus according to claim 8, wherein the grinding wheel comprises a base material made of a metal material and abrasive grains fixed to the outer surface of the base material.

10. In the processing apparatus according to claim 8 or 9, the grinding wheel has a helical grinding portion formed on the outer circumferential surface located between the front end surface and the rear end surface, The grinding section is a processing device for grinding the teeth of a gear.

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