Holding jig

Abstract

Provided is a holding jig for holding, inside a vacuum container that generates plasma, a hob cutter which has a cylindrical shape and to the outer periphery of which is provided a cutting blade that has rake face formed along the axial direction of the hob cutter, said holding jig comprising: a pole member which is columnar and which is inserted through the hob cutter; a pair of flange members through which the pole member is inserted in such a manner that the pair of flange members sandwich the hob cutter from both sides along the axial direction; a mask plate which is attached to the pair of flange members and which covers the rake face and protects the rake face from the plasma; and a fixing mechanism which fixes the pole member to the pair of flange members in a state in which the mask plate is positioned with respect to the rake face.

Description

Holding jig

[0001] The present invention relates to a holding jig for holding a hob cutter inside a vacuum vessel.

[0002] Conventionally, by applying a coating treatment to the surface of a base material made of tool steel or cemented carbide, in addition to the inherent properties of the base material, properties such as wear resistance and heat resistance are further imparted, resulting in so-called coated tools or coated cutters. As such tools are used, the coating formed on the surface wears or peels off, reaching the end of its life. Conventionally, such used tools are often discarded without being reused as they are, but in recent years, they are being recycled by thoroughly removing (debonding) the coating on the surface of the used tools and then forming a film again.

[0003] As an apparatus for removing the coating on the surface of a tool using plasma, for example, the coating removal apparatus shown in Patent Document 1 is known. This coating removal apparatus firmly holds and fixes the tool, which is the object to be processed, using a dedicated holding jig on a disk-shaped stage installed inside a vacuum vessel, introduces argon gas into the vacuum vessel, and generates an inductively coupled plasma in the vacuum chamber using an antenna installed outside the vacuum vessel, and is configured to remove the film by causing positive ions in the plasma to impinge on the coating on the surface of the drill by applying a bias voltage to the stage.

[0004] Japanese Patent Application Laid-Open No. 2023-004296

[0005] When removing the film of a hob cutter by plasma treatment using the above-described coating removal apparatus, prior to the film removal by plasma treatment, regrinding of the rake face, which is severely worn, is performed as a pretreatment. Therefore, during the plasma treatment, the base material is exposed on the rake face, and the rake face is preferentially worn.

[0006] The present invention has been made to solve such problems, and its main object is to provide a new holding jig that can firmly hold a hob cutter inside a vacuum vessel and suppress the wear of the rake face due to plasma.

[0007] In other words, the holding jig according to the present invention is a holding jig for holding a hob cutter, which is cylindrical in shape and has a cutting blade with a rake face formed along its axial direction on its outer circumference, in a vacuum vessel that generates plasma, and is characterized by comprising: a columnar pole member through which the hob cutter is inserted; a pair of flange members inserted into the pole member so as to sandwich the hob cutter from both sides along its axial direction; a mask plate attached to the pair of flange members to cover the rake face and protect it from the plasma; and a fixing mechanism for fixing the pair of flange members to the pole member while the mask plate is positioned relative to the rake face.

[0008] With this configuration, the hob cutter inserted through the pole member is sandwiched between flange members on both sides and fixed with a fixing mechanism, thereby securely fixing the hob cutter inside the vacuum chamber. Moreover, since the flange member to which the mask plate is attached can be fixed to the pole member while the mask plate is positioned relative to the rake face, misalignment of the mask plate relative to the rake face can be prevented, and wear of the rake face due to plasma can be suppressed.

[0009] Furthermore, a specific embodiment of the holding jig is one in which the fixing mechanism comprises a through-screw hole formed from the outer circumferential surface to the inner circumferential surface of the flange member, and a screw member attached to the through-screw hole, and the flange member is fixed to the pole member by rotating the screw member in a screwing motion and pressing its tip against the outer surface of the pole member. In this way, the flange member can be firmly brought into contact with the pole member by screwing in the screw member, effectively preventing misalignment of the mask plate with respect to the rake face, and more effectively suppressing wear on the rake face.

[0010] Furthermore, the holding jig has a keyway formed on the inner circumferential surface of the hob cutter that extends axially, a projection corresponding to the keyway formed on the outer surface of the pole member that extends axially, and a recessed groove corresponding to the projection formed on the inner circumferential surface of the flange member that extends axially, preferably with the width of the recessed groove being wider than the width of the keyway. In this way, the flange member has a greater rotational margin than the hob cutter, so by inserting the hob cutter and flange member into the pole member and rotating the flange member with the mask plate attached to the flange member, the mask plate can be firmly pressed against the rake face. Then, by fixing the flange member to the pole member in this state, the gap between the mask plate and the rake face can be reduced as much as possible, and wear on the rake face can be further suppressed.

[0011] Furthermore, in a specific embodiment of the holding jig, it is preferable that the flange member is inserted into the pole member with the position of the groove aligned with the position of the protrusion, and the through screw hole is formed to intersect the protrusion, and the flange member is fixed to the pole member by rotating the screw member to screw it in and pressing its tip against the side surface of the protrusion. In this way, the flange member can be rotated by screwing in the screw member, thereby making the mask plate tightly attached to the rake face and further reducing the gap between the mask plate and the rake face.

[0012] Furthermore, the holding jig has a pair of flanges into which slits are formed along the axial direction into which the ends of the mask plates are inserted, and it is preferable that multiple such slits are formed along the circumferential direction. In this way, by attaching multiple mask plates to the pair of holding jigs, multiple rake faces of the hob cutter can be shielded together.

[0013] Furthermore, it is preferable that the holding jig includes a covering portion of the mask plate formed to match the shape of the rake face. In this way, since the shape of the mask plate and the rake face match, the rake face can be shielded along with the cutting edge, while the flank face can be fully exposed to the plasma. This effectively suppresses wear on the rake face and cutting edge, while thoroughly removing the coating from the flank face.

[0014] According to the present invention configured in this manner, it is possible to provide a new holding jig that can securely hold a hob cutter in a vacuum container and suppress wear of the rake face due to plasma.

[0015] A schematic diagram showing the configuration of a coating removal device according to one embodiment of the present invention. A schematic diagram showing the configuration of a hob cutter, which is the workpiece to be processed in the same embodiment. A schematic diagram showing the state in which the hob cutter is held using the holding jig of the same embodiment. A schematic diagram showing the state of the holding jig of the same embodiment before assembly. A diagram illustrating the shape of the mask plate of the holding jig and the rake face of the hob cutter in the same embodiment. A plan view of the hob cutter held in the holding jig of the same embodiment, viewed from the axial direction. A cross-sectional view of the hob cutter held in the holding jig of the same embodiment. A cross-sectional view showing the configuration of the fixing mechanism of the holding jig of the same embodiment. A schematic diagram showing the state in which the hob cutter is held using the holding jig of another embodiment. A schematic diagram showing the state of the holding jig of the same embodiment before assembly. A plan view of the hob cutter held in the holding jig of the same embodiment, viewed from the axial direction. A cross-sectional view of the hob cutter held in the holding jig of the same embodiment. A cross-sectional view showing the configuration of the fixing mechanism of the holding jig of the same embodiment. A schematic diagram showing the hob cutter being held using a holding jig of another embodiment. A schematic diagram showing the holding jig of the same embodiment before assembly. A plan view of the hob cutter held in the holding jig of the same embodiment, viewed from the axial direction. A cross-sectional view of the hob cutter held in the holding jig of the same embodiment. A cross-sectional view showing the configuration of the fixing mechanism of the holding jig of the same embodiment.

[0016] A holding jig 100 according to one embodiment of the present invention will be described below with reference to the drawings.

[0017] <Device Configuration> The holding jig 100 of this embodiment is used in a coating removal device 300 that removes a coating formed on the surface of a hob cutter 200 by plasma treatment using inductively coupled plasma.

[0018] Specifically, as shown in Figure 1, the coating removal device 300 comprises a vacuum vessel V forming a processing chamber S into which a gas is introduced and which is evacuated by vacuum, an antenna A provided outside the vacuum vessel V, and a high-frequency power supply P1 for applying high frequency to the antenna A. In this configuration, by applying high frequency from the high-frequency power supply P1 to the antenna A, a high-frequency current flows through the antenna A, an induced electric field is generated inside the vacuum vessel V, and an inductively coupled plasma is produced. In this embodiment, the plasma source is composed of the antenna A and the high-frequency power supply P1 for applying high frequency to it.

[0019] First, let me explain the hob cutter 200, which is the target of plasma treatment. The hob cutter 200 is what is known as a coated tool or coated tool, and it is made of a base material made of tool steel or cemented carbide, for example, on which a coating (also called a coating film) is formed on the surface.

[0020] The hob cutter 200 is a general type, as shown in Figure 2, and has a cylindrical shape with a cutting blade CE having a rake face RF formed along its axial direction on its outer circumference. In the hob cutter 200 of this embodiment, the rake face RF is formed to be substantially parallel to the axial direction and substantially parallel to the radial direction. Multiple rows of these cutting blades CE are provided at intervals along the rotational direction of the hob cutter 200. A mounting hole MH is formed along the axial direction in the center of the hob cutter 200, which can be attached to the hob shaft. This mounting hole is a through hole formed from the top surface to the bottom surface of the hob cutter 200. A keyway KW is formed straight along the axial direction on the inner circumferential surface of the hob cutter 200 to prevent displacement in the rotational direction after attachment to the hob shaft.

[0021] Next, the various parts of the coating removal device 300 will be described. As shown in Figure 1, the antenna A is positioned to face the side wall of the vacuum vessel V. In this embodiment, two antennas A are provided so as to face each of the opposing pair of side walls of the vacuum vessel V, but the number of antennas A is not limited to this, and may be one or three or more. The antenna A in this embodiment is rod-shaped and is positioned upright along the axial direction (vertical direction) of the vacuum vessel V.

[0022] Antenna A has one end, the feed end, connected to a high-frequency power supply P1 via a matching circuit C, and the other end, the termination end, is directly grounded. The termination end may also be grounded via a capacitor or coil.

[0023] The high-frequency power supply P1 can supply high-frequency current to antenna A via a matching circuit C. The high-frequency value is, for example, a common 13.56 MHz, but is not limited to this and may be changed as appropriate.

[0024] The coating removal device 300 has a magnetic field transmission window W that allows the magnetic field generated from antenna A to pass through. Specifically, the coating removal device 300 is equipped with a dielectric plate that closes an opening formed in the wall of the vacuum container V from the outside of the vacuum container V, and this dielectric plate forms the magnetic field transmission window W.

[0025] The coating removal device 300 is equipped with a turntable R near the lower wall of the vacuum chamber V for rotating the hob cutter 200, which is the object to be processed, inside the vacuum chamber V. Multiple hob cutters 200 are set on the upper surface of the turntable R. The coating removal device 300 is also equipped with a bias power supply P2 for applying a bias voltage to the turntable R. The bias voltage is, for example, a negative DC voltage, but is not limited to this. This bias voltage allows control of the energy of positive ions in the plasma when they are incident on the coating on the surface of the hob cutter 200, thereby controlling the coating removal speed.

[0026] With this configuration, when a high frequency is applied from the high-frequency power supply P1 to antenna A, the high-frequency magnetic field generated from antenna A passes through the magnetic field transmission window W and is formed (supplied) inside the vacuum container V. This generates an induced electric field in the space inside the vacuum container V, and an inductively coupled plasma is generated. Then, by applying a bias voltage to the rotating table R, positive ions in the plasma are incident on the coating on the surface of the hob cutter 200, thereby removing the coating formed on the surface of the hob cutter 200.

[0027] In this embodiment, the hob cutter 200 is installed and held inside the vacuum container V (specifically on the upper surface of the rotating table R) using a dedicated holding jig 100.

[0028] Specifically, as shown in Figures 3 to 8, the holding jig 100 comprises a columnar pole member 1 through which the hob cutter 200 is inserted, a pair of flange members 2 inserted through the pole member 1 and sandwiching the hob cutter 200 from both sides along the axial direction, and a mask plate 3 attached to the pair of flange members 2 and covering the rake face RF to protect it from plasma. Using this holding jig 100, the hob cutter 200 is held in the vacuum vessel V with its axial direction aligned with the vertical direction.

[0029] The pole member 1 has a circular cross-section, and its outer diameter is approximately the same as the inner diameter of the hob cutter 200. The pole member 1 is set upright on the upper surface of the turntable R.

[0030] The flange member 2 is substantially disc-shaped, and a mounting hole 21 for attaching it to the pole member 1 is formed in its center along the axial direction. The inner diameter of the mounting hole 21 is substantially the same as the outer diameter of the pole member 1.

[0031] The flange member 2 is composed of multiple parts with different outer diameters, and in this embodiment, it is composed of a large-diameter portion 2A with a relatively large diameter and a small-diameter portion 2B with a relatively small diameter. Both the large-diameter portion 2A and the small-diameter portion 2B are disc-shaped and are formed integrally and continuously along the axial direction. The pair of flange members 2 are inserted into the pole member 1 so that their large-diameter portions 2A face each other. The surface of the large-diameter portion 2A functions as a pressing surface 22 that presses the end face SU of the hob cutter 200 in the axial direction, and the hob cutter 200 is pressed from both sides in the axial direction by the respective pressing surfaces 22 of the pair of large-diameter portions 2A.

[0032] A slit 2s is formed on the circumferential surface 23 of each flange member 2, into which the end portion 31 of the mask plate 3 is inserted. This slit 2s is formed on the circumferential surface 23 of the large-diameter portion 2A of the flange member 2, parallel to the axial direction, and having a constant depth in the radial direction. Multiple slits 2s are formed at approximately equal intervals along the circumferential direction. The spacing between each slit 2s is the same as the spacing between each rake face RF formed on the hob cutter 200.

[0033] As shown in Figure 5, the mask plate 3 is a long, plate-like structure with a certain thickness, and is mounted so as to straddle the pair of flange members 2. Both ends 31 of the mask plate 3 are inserted into the respective slits 2s of the pair of flange members 2 and are fixed in place by a mounting mechanism 4, which will be described later. In the central region of the mask plate 3 in the longitudinal direction, a shielding portion 32 is formed to shield the rake face RF. The plate surface of this shielding portion 32 functions as a shielding surface and has approximately the same dimensions and shape as the rake face RF.

[0034] The holding jig 100 also includes a mounting mechanism 4 for attaching the mask plate 3 to a pair of flange members 2. This mounting mechanism 4 consists of bolt holes formed in the circumferential surface 23 and bolts that are screwed into the bolt holes and move back and forth. The bolt holes have one end opening to the circumferential surface 23 and the other end opening to the slit 2s, and are formed to be perpendicular to the axial direction and torsion with respect to the axial direction. The mask plate 3 can be fixed by inserting the end 31 of the mask plate 3 into the slit 2s plate and then screwing the bolts into the bolt holes and pressing them against the surface of the end 31 of the mask plate 3. The mounting mechanism 4 is provided corresponding to each of the multiple slits 2s.

[0035] The holding jig 100 is equipped with a fixing mechanism 5 that fixes a pair of flange members 2 to the pole member 1 while the mask plate 3 is positioned relative to the scoop surface RF.

[0036] This fixing mechanism 5 comprises a through-screw hole 51 formed from the outer circumferential surface 23 to the inner circumferential surface of the flange member 2 (specifically the small-diameter portion 2B), and a screw member 52 attached to the through-screw hole 51. By rotating the screw member 52 to screw it in and pressing its tip against the outer surface 1s of the pole member 1, the flange member 2 is fixed to the pole member 1. In this embodiment, the through-screw hole 51 is formed to extend straight along the radial direction. Such a fixing mechanism 5 is provided on both of the pair of flange members 2.

[0037] By rotating the pair of flange members 2 to which the mask plate 3 is attached relative to the hob cutter 200, and with the shielding surface of the mask plate 3 in contact with the scooping surface RF, the screw member 52 of the fixing mechanism 5 is screwed in and brought into contact with the outer surface 1s of the pole member 1, thereby fixing the pair of flange members 2 to the pole member 1 while positioning the mask plate 3 with respect to the scooping surface RF.

[0038] <Effects of this embodiment> With the holding jig 100 of this embodiment configured as described above, the hob cutter 200 inserted through the pole member 1 is sandwiched between the flange members 2 from both sides and fixed with the fixing mechanism 5, thereby securely fixing the hob cutter 200 inside the vacuum chamber. Moreover, since the flange member 2 to which the mask plate 3 is attached can be fixed to the pole member 1 while the mask plate 3 is positioned relative to the rake face RF, misalignment of the mask plate 3 relative to the rake face RF is prevented, and wear of the rake face RF due to plasma can be suppressed.

[0039] <Other Modified Embodiments> The present invention is not limited to the embodiments described above.

[0040] For example, in other embodiments of the holding jig 100, as shown in Figures 9 to 13, a projection 1p corresponding to the keyway KW of the hob cutter 200 may be formed along the axial direction on the outer surface 1s of the pole member 1. Furthermore, a groove 2v corresponding to the projection 1p of the pole member 1 may be formed along the axial direction on the inner circumferential surface of the flange member 2. The hob cutter 200 may be inserted into the pole member 1 with its keyway KW aligned with the projection 1p, and the flange member 2 may be inserted into the pole member 1 with its groove 2v aligned with the projection 1p.

[0041] In this case, it is preferable that the groove 2v formed in the flange member 2 is wider than the keyway KW of the hob cutter 200. That is, it is preferable that the width of the groove 2v is set such that the flange member 2 has a greater rotational margin than the hob cutter 200 when inserted through the pole member 1.

[0042] Also, in the holding jig 100 of the above embodiment, the through-hole 51 provided in the fixing mechanism 5 was formed to extend straight along the radial direction, but it is not limited to this. In the holding jig 100 of other embodiments, as shown in FIGS. 14 to 18, the through-hole 51 provided in the fixing mechanism 5 may be formed to be perpendicular to the axial direction and to be in a twisted relationship with respect to the axial direction. More specifically, in a state where the flange member 2 is inserted into the pole member 1 such that its concave groove 2v is aligned with the protrusion 1p, the through-hole 51 may be formed to intersect the protrusion 1p of the pole member 1. Even more specifically, the through-hole 51 may be formed such that one end thereof opens to the peripheral surface 23 of the flange member 2 (specifically, the small-diameter portion 2B), and the other end opens to the concave groove 2v.

[0043] In the holding member having such a configuration, when the hob cutter 200 and the pair of flange members 2 are inserted into the pole member 1 to set the mask plate 3, and in this state, the screw member 52 of the fixing mechanism 5 is screwed in, the tip of the screw member 52 contacts the side surface of the protrusion 1p of the pole member 1, so that the pair of flange members 2 and the mask plate 3 rotate, and the shielding surface of the mask plate 3 is pressed against the scooping surface RF.

[0044] Also, the holding jig 100 of the above embodiment holds one hob cutter 200, but it is not limited to this, and a plurality of hob cutters 200 communicating with the pole member 1 may be held together. Thereby, the productivity of film removal can be improved.

[0045] Needless to say, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention.

[0046] According to the present invention, it is possible to provide a new holding jig that can firmly hold a hob cutter in a vacuum vessel and suppress the wear of the scooping surface due to plasma.

[0047] V ··· Vacuum vessel 100 ··· Holding jig 1 ··· Pole member 2 ··· Flange member 2s ··· Slit 3 ··· Mask plate 5 ··· Fixing mechanism 200 ··· Hob cutter RF ··· Scooping surface

Claims

1. A holding jig for holding a hob cutter, which is cylindrical in shape and has a cutting blade with a rake face formed along its axial direction on its outer circumference, in a vacuum vessel that generates plasma, comprising: a columnar pole member through which the hob cutter is inserted; a pair of flange members inserted into the pole member so as to sandwich the hob cutter from both sides along its axial direction; a mask plate attached to the pair of flange members to cover the rake face and protect it from the plasma; and a fixing mechanism for fixing the pair of flange members to the pole member while the mask plate is positioned relative to the rake face.

2. The holding jig according to claim 1, wherein the fixing mechanism comprises a through screw hole formed from the outer circumferential surface to the inner circumferential surface of the flange member, and a screw member attached to the through screw hole, and the flange member is fixed to the pole member by rotating the screw member in a screwing motion and pressing its tip against the outer surface of the pole member.

3. The holding jig according to claim 2, wherein a keyway extending in the axial direction is formed on the inner circumferential surface of the hob cutter, a projection corresponding to the keyway is formed on the outer surface of the pole member in the axial direction, and a recessed groove corresponding to the projection is formed on the inner circumferential surface of the flange member in the axial direction, wherein the width of the recessed groove is wider than the width of the keyway.

4. The holding jig according to claim 3, wherein the flange member is inserted into the pole member with the position of the groove aligned with the position of the protrusion, the through screw hole is formed to intersect the protrusion, and the flange member is fixed to the pole member by rotating the screw member to screw it in and pressing its tip against the side surface of the protrusion.

5. The holding jig according to claim 1, wherein the pair of flanges have slits formed along the axial direction into which the ends of the mask plate are inserted, and a plurality of such slits are formed along the circumferential direction.

6. The holding jig according to claim 5, wherein the mask plate has a covering portion formed to match the shape of the scooping surface.

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