Cutting wheel fitting structure

Abstract

To provide a cutting wheel fitting structure that can stably supply a cooling liquid to a cutting wheel, and can detachably and appropriately fit the cutting wheel to a drive shaft.SOLUTION: A fitting structure of a cutting wheel 20 capable of supplying a cooling liquid comprises: a drive shaft part 11 comprising a rotating stop shank part 11a and a male threaded shaft part 11b; an inner flange 61 which engages with the rotating stop shaft part 11a, and receives the cutting wheel 20; a lock nut 62 which engages with the male threaded shaft part, and pinches and fixes the cutting wheel; a cooling liquid introduction mechanism 84, 86 which is configured in at least one of the drive shaft 11 and the lock nut 62, and guides the supplied cooling liquid to an inflow port 35a; and a supply joint part 63 comprising a connection male screw member 92 channel-connected to the cooling liquid introduction mechanism 84, 86, and a joint body 91 channel-connected to a cooling liquid supply source.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a mounting structure for a cutting grindstone for mounting a cutting grindstone on a cutting device such as a disk grinder, and particularly relates to a structure that enables the supply of a coolant to a cutting grindstone with a coolant specification.

Background Art

[0002] Conventionally, as a mounting structure for this type of cutting grindstone, a rotary blade having a through-hole for a cooling medium inside is known to be fitted into a hollow drive shaft having a fluid flow path (see Patent Document 1). This device includes a drive shaft having a hollow portion as a fluid flow path, a manifold through which the drive shaft penetrates in a watertight and rotatable manner, and a liquid supply source that supplies a cooling medium to the manifold via a conduit. The rotary blade is fitted to the tip of the drive shaft. The cooling medium from the supply source is supplied to the manifold via a conduit. In the manifold, the cooling medium is supplied to the fluid flow path of the rotating drive shaft from the opening end on the manifold side, and further, the cooling medium is supplied from the rotary blade open end formed at the tip to the through-hole of the rotary blade. The cooling medium that has flowed into the rotary blade is supplied to the blade portion through the through-hole and the holes.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such a conventional mounting structure in which a rotary blade (cutting grindstone) is fitted to a drive shaft having a hollow portion as a fluid flow path for a cooling medium at the mounting hole portion, this fitting portion has a fragile structure. For this reason, there has been a problem that it is impossible to achieve both the stable supply of the coolant to the rotary blade (cutting grindstone) and the detachable and proper mounting of the rotary blade to the drive shaft.

[0005] An object of the present invention is to provide a mounting structure for a cutting wheel that can achieve both stably supplying a coolant to the cutting wheel and detachably and appropriately mounting the cutting wheel to a drive shaft.

Means for Solving the Problems

[0006] The mounting structure of the cutting wheel of the present invention is a mounting structure of a cutting wheel capable of supplying a coolant during rotational driving to a cutting wheel in which an inlet of a coolant flow path is formed in a hole forming portion of a mounting hole, and includes a rotation prevention shaft portion provided on the device body side and a male screw-shaped shaft portion protruding from the rotation prevention shaft portion, a drive shaft for rotationally driving the mounted cutting wheel, an inner flange that engages with the rotation prevention shaft portion and receives the cutting wheel mounted on the male screw-shaped shaft portion, a lock nut having a female screw-shaped portion that screws onto the male screw-shaped shaft portion and sandwiches and fixes the cutting wheel between the inner flange, and a coolant introduction mechanism configured in at least one of the drive shaft and the lock nut in a state where the lock nut is screwed onto the drive shaft, and guiding the coolant supplied from a coolant supply source to the inlet, and a supply joint portion having a shaft-shaped rotating portion fluidly connected to the coolant introduction mechanism coaxially with the drive shaft and a non-rotating member portion fluidly connected to the coolant supply source, the shaft-shaped rotating portion having an axial center flow path communicating with the coolant introduction mechanism, and the non-rotating member portion surrounding the shaft-shaped rotating portion and having an annular liquid reservoir communicating with the axial center flow path from a radial direction and a connection port portion communicating with the annular liquid reservoir and to which the coolant supply source is connected.

[0007] According to this configuration, the cutting wheel can be reliably attached (mounted) to the drive shaft in a form of sandwiching and fixing the cutting wheel between the inner flange and the lock nut. Thereby, the cutting wheel can be detachably and appropriately mounted to the drive shaft. Also, in this state, coolant can be supplied from the supply joint portion to the cutting grindstone via the coolant introduction mechanism. In this case, since the coolant is guided from the annular liquid reservoir communicating with the connection port portion of the non-rotating member portion through the axial center flow path of the shaft-shaped rotating portion to the coolant introduction mechanism, the coolant can be smoothly supplied from the non-rotating member portion that does not rotate to the rotating coolant introduction mechanism and the cutting grindstone. Therefore, the coolant can be stably supplied to the cutting grindstone.

[0008] In this case, it is preferable that the coolant introduction mechanism includes an annular coolant reservoir configured between the lock nut and the cutting grindstone so that the inlet faces it, and an introduction flow path portion whose upstream side communicates with the axial center flow path and whose downstream side communicates with the coolant reservoir.

[0009] According to this configuration, the cutting grindstone clamped and fixed between the inner flange and the lock nut has the inlet of the coolant facing the annular coolant reservoir. On the other hand, the coolant flowing in from the introduction flow path of the supply joint portion is guided to the coolant reservoir through the introduction flow path portion. Then, the coolant in the coolant reservoir is supplied to the cutting grindstone through the inlet. Since centrifugal force acts on the coolant supplied to the rotating cutting grindstone, the coolant flowing in from the supply joint portion is smoothly guided to the cutting grindstone through the introduction flow path portion and the coolant reservoir.

[0010] In this case, it is preferable that the introduction flow path portion includes a recessed flow path recessed and formed on the inner peripheral surface of the female screw-shaped portion and extending axially along the female screw-shaped portion from the coolant reservoir, and a communication flow path communicating the recessed flow path with the axial center flow path.

[0011] According to this configuration, by simply forming a recessed flow path extending axially in the female screw-shaped portion of the lock nut that is screwed onto the male screw-shaped shaft portion, a flow path for the coolant can be formed near the axial center without impairing the screw function of the lock nut. Note that it is preferable to form a pair of the recessed flow paths extending axially at symmetric positions 180° in the circumferential direction.

[0012] Similarly, the introduction flow path portion preferably has an annular groove flow path formed on the outer peripheral surface of the male screw-shaped shaft portion so as to face the coolant reservoir, a linear flow path formed on the outer peripheral surface of the male screw-shaped shaft portion and extending from the annular groove flow path to the tip of the male screw-shaped shaft portion, and a communication flow path that communicates the linear flow path and the axial center flow path.

[0013] According to this configuration, by simply forming the annular groove flow path and the linear flow path connected thereto on the outer peripheral surface of the male screw-shaped shaft portion, a coolant flow path can be easily formed in the vicinity of the axial center. Note that it is preferable to form a pair of linear flow paths extending in the axial direction at symmetric positions 180° apart in the circumferential direction.

[0014] Similarly, the introduction flow path portion preferably has a radial hole flow path formed on the outer peripheral surface of the male screw-shaped shaft portion so as to face the coolant reservoir, an axial hole flow path formed in the axial center portion of the male screw-shaped shaft portion and extending from the radial hole flow path to the tip of the male screw-shaped shaft portion, and a communication flow path that communicates the axial hole flow path and the axial center flow path.

[0015] According to this configuration, by simply forming the radial hole flow path and the axial hole flow path connected thereto in the male screw-shaped shaft portion, a coolant flow path can be easily formed at and in the vicinity of the axial center. Note that the radial hole flow path preferably penetrates the male screw-shaped shaft portion in the radial direction.

[0016] Further, the drive shaft has an extension shaft portion that is continuous with the base end side of the male screw-shaped shaft portion, penetrates the device body, and extends to the opposite side, and the supply joint portion is attached to the extension shaft portion. The introduction flow path portion preferably has a radial hole flow path formed on the outer peripheral surface of the male screw-shaped shaft portion so as to face the coolant reservoir, an extension axial hole flow path formed in the axial center portions of the male screw-shaped shaft portion and the extension shaft portion and extending from the radial hole flow path to the tip of the extension shaft portion, and a communication flow path that communicates the extension axial hole flow path and the axial center flow path.

[0017] According to this configuration, an inner flange, a cutting grindstone, and a lock nut are attached to one end of a drive shaft that penetrates the device body, and a supply joint portion is attached to the other end. Therefore, the weight balance of the device body during hand operation is maintained well, and the operability is not impaired. On the other hand, by simply forming a radial hole flow path and an extension shaft direction hole flow path connected thereto in the male screw-shaped shaft portion and the extension shaft portion, a coolant flow path can be easily formed at the axis center and in the vicinity of the axis center.

[0018] On the other hand, it is preferable that the inner flange has a first seal member that seals between the inner flange and the cutting grindstone and a second seal member that seals between the inner flange and the male screw-shaped shaft portion.

[0019] According to this configuration, since the space between the inner flange and the cutting grindstone is sealed by the first seal member and the space between the inner flange and the male screw-shaped shaft portion is sealed by the second seal member, the coolant does not leak to the device body side through the inner flange or the male screw-shaped shaft portion, and it is possible to effectively prevent the coolant from accidentally entering the device body.

[0020] Further, it is preferable that the lock nut has a third seal member that seals between the lock nut and the cutting grindstone.

[0021] According to this configuration, since the space between the lock nut and the cutting grindstone is sealed by the third seal member, the coolant does not leak from the lock nut, and it is possible to effectively prevent unnecessary leakage of the coolant.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Embodiments for Carrying Out the Invention

[0023] With reference to the attached drawings, a case where the mounting structure of a cutting grindstone according to an embodiment of the present invention is applied to a cutting device will be described. This cutting device has a basic form of a disk grinder, attaches a cutting grindstone which is a disk, and cuts concrete, mortar, tiles, etc. by grinding. The cutting grindstone of the embodiment has a coolant flow path inside, and the cutting device has a function of supplying coolant to the cutting grindstone and a function of collecting cooling waste liquid mixed with grinding powder when cutting an object. For this reason, although omitted in these figures, a coolant supply device constituting a coolant supply source and a cooling waste liquid recovery device are connected to the cutting device.

[0024] [Cutting device] FIG. 1 is an external perspective view of a cutting device according to an embodiment. FIG. 2 is an external perspective view of the cutting device with the disk cover removed. As shown in these figures, the cutting device 10 has a basic form of a so-called disk grinder in which a drive shaft 11 for attaching a cutting grindstone 20 (disk) is exposed, and includes a motor 12 having the drive shaft 11, a device body 13 incorporating the motor 12, a mounting unit 14 for supplying coolant to the cutting grindstone 20 mounted on the drive shaft 11, and a disk cover 16 for covering the cutting grindstone 20. And the mounting structure 15 of the cutting grindstone 20 referred to in the claims is constituted by the drive shaft 11 and the mounting unit 14.

[0025] Further, the cutting device 10 includes a cover holder 17 for holding the disk cover 16 on the device body 13 and a stopper arm 18 for preventing a part of the mounting unit 14 from rotating. And although details will be described later, a coolant supply device (see FIG. 6) is connected to the mounting unit 14 of the cutting device 10 configured as described above via a liquid supply tube 21, and a cooling waste liquid recovery device (not shown) is connected to the disk cover 16 via a waste liquid tube 22.

[0026] The device body 13 incorporating the motor 12 is in a substantially cylindrical shape as a hand-held power tool, with a disk mounting base 24 disposed on the tip side, and a drive shaft 11 protruding from the center of the disk mounting base 24. A power cord 25 is connected to the proximal end of the device body 13. The power cord 25, the liquid supply tube 21, and the waste liquid tube 22 are integrally bundled so as not to interfere with the work.

[0027] [Cutting grindstone] Figure 3 is a structural view of the cutting grindstone. As shown in the figure, the cutting grindstone 20 is a so-called diamond wheel, and includes a disc-shaped blade substrate 31 having a mounting hole 32 for the drive shaft 11 at the center, a plurality (8) of segment chips 33 brazed to the outer peripheral end of the blade substrate 31, a plurality (8 locations) of relief grooves 34 formed in the outer peripheral portion of the blade substrate 31, and a plurality (8) of coolant flow paths 35 formed radially inside the blade substrate 31. The blade substrate 31 is formed by bonding a thin plate disc-shaped first substrate 40 and a thin plate disc-shaped second substrate 50 (see Fig. 3(b)).

[0028] The first substrate 40 is formed with a first mounting hole 41 constituting the mounting hole 32, eight first U-shaped grooves 42 constituting the relief grooves 34, and eight first flow path grooves 43 constituting the coolant flow paths 35. Similarly, the second substrate 50 is formed with a second mounting hole 51 constituting the mounting hole 32, eight second U-shaped grooves 52 constituting the relief grooves 34, and eight second flow path grooves 53 constituting the coolant flow paths 35. The blade substrate 31 is configured by spot-welding the thus-formed first substrate 40 and second substrate 50 with their back surfaces attached to each other at eight welding locations 55 (see Fig. 3(a)).

[0029] The cutting grindstone 20 configured as described above is mounted on the drive shaft 11 such that the first substrate 40 is positioned on the inner side (the side of the apparatus body 13) and the second substrate 50 is positioned on the outer side. On the other hand, the second mounting hole 51 is formed to have a larger diameter than the first mounting hole 41 (see Fig. 3(b)). As a result, a mounting hole 32 having an annular stepped portion 32a is formed at the center of the blade substrate 31. That is, an annular stepped portion 32a is formed in the hole forming portion of the mounting hole 32. Although details will be described later, in the cutting grindstone 20 of the present embodiment, the coolant is supplied from this annular stepped portion 32a.

[0030] In the annular stepped portion 32a, the inlets 35a of the respective coolant channels 35 are open, and at the bottom of each relief groove 34, the outlets 35b of the respective coolant channels 35 are open. Therefore, in the cutting grindstone 20, the coolant flows radially from the annular stepped portion 32a into the coolant channels 35 and is further supplied to the segment chips 33 via the relief grooves 34.

[0031] The above-described annular stepped portion 32a constitutes an annular liquid reservoir facing the inlets 35a of the coolant channels 35, but the structure corresponding to this liquid reservoir may be as follows.

[0032] [Modification Example] Fig. 4 shows the structure of a cutting grindstone 20A according to a first modification example. In this cutting grindstone 20A, in the mounting hole 32, the first mounting hole 41 of the first substrate 40 and the second mounting hole 51 of the second substrate 50 are formed to have the same diameter. In addition, a plurality (12 in the illustrated example) of through holes 57 for supplying coolant are formed at the hole edge portion of the second substrate 50 forming the second mounting hole 51.

[0033] Also, the hole edge portions of the first substrate 40 and the second substrate 50 are formed to be thin so that the inner sides are flush with the bottoms of the first flow path groove 43 and the second flow path groove 53, respectively. As a result, an annular inner-substrate reservoir portion 58 facing the inlets 35a of the coolant channels 35 is formed inside both hole edge portions. That is, an inner-substrate reservoir portion 58 is formed in the hole forming portion of the mounting hole 32.

[0034] In this modified example, the coolant mainly flows into the reservoir portion 58 within the substrate between the first substrate 40 and the second substrate 50 from the plurality of through holes 57, and is supplied from this annular reservoir portion 58 within the substrate to each coolant flow path 35 through the inlet 35a.

[0035] FIG. 5 shows the structure of the cutting grindstone 20B according to the second modified example. In this cutting grindstone 20B, different from the first modified example, the through holes 57 are not formed, and only the reservoir portion 58 within the substrate is formed. Also in this case, the reservoir portion 58 within the substrate is formed in the hole forming portion of the mounting hole 32. Therefore, in this modified example, the coolant flows into the reservoir portion 58 within the substrate from the inner end of the mounting hole 32, and is supplied from this reservoir portion 58 within the substrate to each coolant flow path 35 through the inlet 35a.

[0036] Note that the structure around the mounting hole 32 of the above cutting grindstones 20, 20A, and 20B is not particularly shown, but is also applicable to a three - layer stacked cutting grindstone. That is, even in a three - layer stacked cutting grindstone in which a flow path substrate forming the coolant flow path 35 is sandwiched between the first substrate 40 and the second substrate 50, it is preferable to configure the above - mentioned annular step portion 32a, through holes 57, reservoir portion 58 within the substrate, etc. in consideration of the flow of the coolant.

[0037] These cutting grindstones 20, 20A, and 20B are detachably mounted on the drive shaft 11 in a state where coolant can be supplied through the mounting structure 15 of the present embodiment. Hereinafter, four types of mounting structures 15 of the first to fourth embodiments will be described, and any of these mounting structures 15 can correspond to the cutting grindstones 20, 20A, and 20B. Here, the mounting structure 15 will be described in detail taking the cutting grindstone 20 as an example.

[0038] [Mounting Structure (First Embodiment)] With reference to the cross-sectional view of FIG. 6 and the exploded view of FIG. 7, the mounting structure 15 of the cutting grindstone 20 will be described. As shown in both figures, the mounting structure 15 includes a drive shaft 11 protruding from the device body 13 (disk mounting base 24), and a mounting unit 14 attached to the drive shaft 11 while sandwiching the cutting grindstone 20. The drive shaft 11 has an anti-rotation cut shaft portion 11a (anti-rotation shaft portion) and a male screw-shaped shaft portion 11b protruding from the end face of the anti-rotation cut shaft portion 11a coaxially.

[0039] On the other hand, the mounting unit 14 includes an inner flange 61, a lock nut 62, and a supply joint portion 63. In this case, the inner flange 61, the lock nut 62, the supply joint portion 63, and the cutting grindstone 20 are supported by the drive shaft 11, and their order is, from the side of the device body 13 (disk mounting base 24), the inner flange 61, the cutting grindstone 20, the lock nut 62, and the supply joint portion 63 (see FIG. 6).

[0040] The inner flange 61 has a function of engaging with the anti-rotation cut shaft portion 11a of the drive shaft 11 and positioning the cutting grindstone 20 coaxially with the drive shaft 11. The lock nut 62 is screwed onto the male screw-shaped shaft portion 11b of the drive shaft 11 to sandwich the cutting grindstone 20 between it and the inner flange 61, and has a function of supplying coolant to the coolant flow path 35 (annular stepped portion 32a) of the cutting grindstone 20. And the supply joint portion 63 has a function of supplying the coolant supplied from a coolant supply device (not shown) to the rotating lock nut 62.

[0041] As shown in FIGS. 6, 7, and 8, the inner flange 61 is integrally formed with a shaft engaging portion 71 that engages with the anti-rotation cut shaft portion 11a of the drive shaft 11, a substrate fitting portion 72 that is continuous with the shaft engaging portion 71 and positions the cutting grindstone 20 (blade substrate 31) coaxially with the drive shaft 11, and a sandwiching contact receiving portion 73 that is continuous with the shaft engaging portion 71 and contacts the cutting grindstone 20. Also, an insertion hole 74 through which the male screw-shaped shaft portion 11b of the drive shaft 11 is inserted is formed at the axial center of the inner flange 61.

[0042] A first O-ring 75 is interposed between the shaft engaging portion 71 and the male screw-shaped shaft portion 11b so as to be positioned by the anti-rotation cut shaft portion 11a. Thereby, the space between the inner flange 61 and the male screw-shaped shaft portion 11b is sealed, and leakage of the coolant to the device body 13 side is prevented. Similarly, a second O-ring 76 is mounted in a circular groove formed between the substrate fitting portion 72 and the sandwiching contact receiving portion 73. Thereby, the space between the inner flange 61 and the cutting grindstone 20 is sealed, and leakage of the coolant from the portion of the sandwiching contact receiving portion 73 is prevented.

[0043] Thus, the first O-ring 75 and the second O-ring 76 effectively prevent the coolant from leaking to the device body 13 side through the inner flange 61 and the male screw-shaped shaft portion 11b, and also prevent the coolant from entering the device body 13.

[0044] In this inner flange 61, the shaft engaging portion 71 is engaged with the anti-rotation cut shaft portion 11a from above by passing the insertion hole 74 through the male screw-shaped shaft portion 11b. In this way, the inner flange 61 is set on the drive shaft 11. For the cutting grindstone 20 with respect to the set inner flange 61, the mounting hole 32 (first mounting hole 41) is fitted into the substrate fitting portion 72 so as to be seated on the sandwiching contact receiving portion 73.

[0045] As shown in FIGS. 6, 7, and 9, the lock nut 62 includes a nut body 81 having a D-cut tool engaging portion 81a formed on the outer peripheral portion, a ring-shaped convex portion 82 protruding from the tip side of the nut body 81, and an annular sandwiching contact portion 83 formed on the base end side of the nut body 81 for sandwiching the cutting grindstone 20 between the nut body 81 and the inner flange 61.

[0046] Further, the lock nut 62 is formed with a recess on the inner side of the clamping contact portion 83, and faces a coolant reservoir 84 that faces the annular stepped portion 32a (inlet 35a) of the cutting grindstone 20. The tip side is connected to the coolant reservoir 84, and it has a female threaded portion 85 that engages with the male threaded shaft portion 11b of the drive shaft 11, two recessed flow paths 86 formed by recessing at two locations of the female threaded portion 85, and coaxially, on the tip side of the female threaded portion 85, a connecting female threaded portion 87 to which a connecting male threaded member 92 described later is screwed.

[0047] In this case, the female threaded portion 85 and the connecting female threaded portion 87 are formed on the axis of the nut body 81. By screwing the lock nut 62 onto the drive shaft 11 via the female threaded portion 85, the drive shaft 11, the inner flange 61, the cutting grindstone 20, and the lock nut 62 are integrated and rotate together.

[0048] The coolant reservoir 84 faces the annular stepped portion 32a of the cutting grindstone 20 on the outside of the screwed male threaded shaft portion 11b, and feeds coolant into the coolant flow path 35 of the cutting grindstone 20. Also, a third O-ring 88 is attached to the coolant reservoir 84 so as to contact the cutting grindstone 20. Thereby, the space between the lock nut 62 and the cutting grindstone 20 is sealed, preventing leakage of the coolant from the portion of the clamping contact portion 83.

[0049] The female threaded portion 85 has a depth sufficient for the length of the male threaded shaft portion 11b. That is, the half portion on the base end side of the female threaded portion 85 constitutes the screwing region 85a of the male threaded shaft portion 11b, and the half portion on the tip side constitutes a non-screwing region 85b that serves as a flow path for the coolant.

[0050] Each recessed flow path 86 is formed to be recessed in the radial direction so as to form a "U" - shaped cross - section in the female - threaded portion 85, and extends from the coolant reservoir 84 to the tip position of the female - threaded portion 85. The two recessed flow paths 86 are recessed so as to notch the thread crest of the female - threaded portion 85 at the 180° point - symmetric positions. That is, the connecting female - threaded portion 87, the non - threaded region 85b of the female - threaded portion 85, the two recessed flow paths 86, and the coolant reservoir 84 are in communication, and coolant can be supplied from the supply joint portion 63 to the cutting grindstone 20 via the lock nut 62.

[0051] Note that the connecting female - threaded portion 87, the non - threaded region 85b of the female - threaded portion 85, the two recessed flow paths 86, and the coolant reservoir 84 constitute the "coolant introduction mechanism" referred to in the claims. The connecting female - threaded portion 87, the non - threaded region 85b of the female - threaded portion 85, and the two recessed flow paths 86 constitute the "introduction flow path portion" referred to in the claims. Further, the connecting female - threaded portion 87 and the non - threaded region 85b of the female - threaded portion 85 constitute the "communication flow path" referred to in the claims.

[0052] As shown in FIGS. 6, 7, 10, and 11, the supply joint portion 63 includes a joint body 91 (see FIG. 10) and a connecting male - threaded member 92 (see FIG. 11) that connects the joint body 91 to the lock nut 62. In this case, the portion where the connecting male - threaded member 92 rotates together with the drive shaft 11 constitutes the "axial rotating portion" referred to in the claims, and the portion where the joint body 91 does not rotate constitutes the "non - rotating member portion" referred to in the claims.

[0053] The connecting male - threaded member 92 is screwed into the connecting female - threaded portion 87 of the lock nut 62 in a state of passing through (penetrating) the joint body 91. A fourth O - ring 93 is provided between the lock nut 62 and the joint body 91, and a fifth O - ring 94 and a spacer ring 95 are provided between the joint body 91 and the head portion 101 of the connecting male - threaded member 92.

[0054] As a result, the joint body 91 is sealed with respect to the coolant supplied between it and the lock nut 62, and allows the lock nut 62 to rotate in this state. That is, a coolant supply device is connected to the joint body 91 via the liquid supply tube 21, and the supply joint portion 63 supplies the coolant to the rotating lock nut 62.

[0055] The connecting male screw member 92 has a head portion 101 and a shaft portion 102, and a male screw 102a that engages with the connecting female screw portion 87 of the lock nut 62 is formed at the tip of the shaft portion 102. An axially bottomed axial hole 103 serving as a coolant flow path is drilled from the male screw 102a side in the axial center of the shaft portion 102. Further, a radial hole 104 that penetrates radially and communicates with the axial hole 103 is formed in the middle portion of the shaft portion 102. Then, the axial hole 103 and the radial hole 104 constitute an axial center flow path 105 for the coolant.

[0056] When the connecting male screw member 92 is screwed into the connecting female screw portion 87 of the lock nut 62, the space between the joint body 91 and the lock nut 62 and the space between the joint body 91 and the head 101 of the connecting male screw member 92 are sealed, and the axial center flow path 105 (axial hole 103) communicates with the connecting female screw portion 87.

[0057] The joint body 91 is integrally formed by a rotation allowance portion 111 through which the connecting male screw member 92 is inserted and a tube connection portion 112 (connection port portion) to which the liquid supply tube 21 is connected. In the rotation allowance portion 111, a first seal receiving hole 113 in which the above-mentioned fourth O-ring 93 is mounted and a second seal receiving hole 114 in which the fifth O-ring 94 and the spacer ring 95 are mounted are formed.

[0058] Further, in the rotation allowance portion 111, a clearance fitting hole 116 is formed between the first seal receiving hole 113 and the second seal receiving hole 114, which forms an annular liquid reservoir 115 of the coolant between the inserted connecting male screw member 92 (shaft portion 102). Thereby, through the radial hole 104 of the connecting male screw member 92, the annular liquid reservoir 115 of the joint body 91 communicates with the axial hole 103 of the connecting male screw member 92. That is, the coolant in the annular liquid reservoir 115 can always be supplied to the connecting male screw member 92 that rotates integrally with the lock nut 62.

[0059] A tapered female screw 117 into which the coupler of the liquid supply tube 21 is screwed is formed in the tube connection portion 112. By connecting the liquid supply tube 21 to the tapered female screw 117, it becomes possible to supply the coolant from the coolant supply device to the joint body 91.

[0060] Note that the tip of the locking arm 18 extending from the cover holder 17 is engaged with the joint body 91 (see FIG. 1). Thereby, the rotation of the joint body 91 with the liquid supply tube 21 connected thereto together with the lock nut 62 is prevented.

[0061] [Mounting Structure (Second Embodiment)] FIG. 12 shows the device structure 15A of the cutting grindstone 20 according to the second embodiment. In this mounting structure 15A, instead of the two recessed flow paths 86, an annular groove flow path 121 and two linear groove flow paths 122 are formed in the male screw-shaped shaft portion 11b. An annular groove flow path 121 is formed in the middle portion in the longitudinal direction of the male screw-shaped shaft portion 11b by engraving it annularly. The mounting hole 32 of the cutting grindstone 20 faces the annular groove flow path 121 in the radial direction, and the outer peripheral surface of the annular groove flow path 121 communicates with the coolant reservoir 84 throughout the area and is part of the coolant reservoir 84.

[0062] The two linear groove flow paths 122 are provided at positions that are point-symmetrical by 180° in the circumferential direction of the male screw-shaped shaft portion 11b and are engraved to the same depth as the annular groove flow path 121. Each linear groove flow path 122 extends perpendicularly from the annular groove flow path 121 and extends to the tip of the male screw-shaped shaft portion 11b.

[0063] As a result, the upstream side of the single-character groove channel 122 communicates with the non-threaded region 85b described above, and the downstream side of the annular groove channel 121 communicates with the coolant reservoir 84. The coolant that has flowed from the axial channel 105 (axial hole 103) of the shaft portion 102 into the non-threaded region 85b of the lock nut 62 reaches the coolant reservoir 84 through the two single-character groove channels 122 and the annular groove channel 121, and is supplied from the coolant reservoir 84 to the cutting grindstone 20 (annular stepped portion 32a).

[0064] In this case, the connecting female screw portion 87, the non-threaded region 85b of the female screw portion 85, the two single-character groove channels 122, the annular groove channel 121, and the coolant reservoir 84 constitute the "coolant introduction mechanism" referred to in the claims. The connecting female screw portion 87, the non-threaded region 85b of the female screw portion 85, the two single-character groove channels 122, and the annular groove channel 121 constitute the "introduction channel portion" referred to in the claims. Furthermore, the connecting female screw portion 87 and the non-threaded region 85b of the female screw portion 85 constitute the "communication channel" referred to in the claims.

[0065] [Mounting Structure (Third Embodiment)] FIG. 13 shows the device structure 15B of the cutting grindstone 20 according to the third embodiment. In this device structure 15B, instead of the two recessed channels 86 described above, a through-hole channel 124 serving as a radial hole channel and an axial-hole channel 125 serving as an axial hole channel are formed in the male screw-shaped shaft portion 11b. A through-hole channel 124 is formed in the middle portion in the longitudinal direction of the male screw-shaped shaft portion 11b so as to penetrate it in the radial direction. The mounting hole 32 of the cutting grindstone 20 faces the through-hole channel 124 in the radial direction, and both ends of the through-hole channel 124 communicate with the coolant reservoir 84.

[0066] The axial-hole channel 125 is drilled through the axis of the male screw-shaped shaft portion 11b, extends perpendicularly from the through-hole channel 124, and extends to the tip of the male screw-shaped shaft portion 11b. That is, one end of the axial-hole channel 125 communicates with the middle portion of the through-hole channel 124, and the other end opens to the non-threaded region 85b of the female screw portion 85.

[0067] As a result, the upstream side of the axial hole flow passage 125 communicates with the non-threaded region 85b, and the downstream side of the through hole flow passage 124 communicates with the coolant reservoir 84. The coolant that flows from the axial hole flow passage 105 (axial hole 103) of the shaft portion 102 into the non-threaded region 85b of the lock nut 62 passes through the axial hole flow passage 125 and the through hole flow passage 124 and reaches the coolant reservoir 84, and is supplied from the coolant reservoir 84 to the cut-off wheel 20 (annular step portion 32a).

[0068] In this case, the connecting female threaded portion 87, the non-threaded region 85b of the female threaded portion 85, the axial hole flow path 125, the through hole flow path 124 and the coolant reservoir 84 constitute the "coolant introduction mechanism" referred to in the claims, the connecting female threaded portion 87, the non-threaded region 85b of the female threaded portion 85, the axial hole flow path 125 and the through hole flow path 124 constitute the "introduction flow path portion" referred to in the claims, and further the connecting female threaded portion 87 and the non-threaded region 85b of the female threaded portion 85 constitute the "communication flow path" referred to in the claims.

[0069] [Mounting structure (fourth embodiment)] 14 shows an apparatus structure 15C for the cut-off wheel 20 according to the fourth embodiment. In this mounting structure 15C, the drive shaft 11 penetrates the apparatus body 13 and extends to the side opposite the cut-off wheel 20, and the above-mentioned supply joint 63 is attached to the extension shaft portion 11c of this drive shaft 11. That is, the extension shaft portion 11c is connected to the base end of the male threaded shaft portion 11b and penetrates the apparatus body 13, and the supply joint portion 63 is attached to its tip portion. Although not shown, a rotation stopper member in place of the rotation stopper arm 18 is engaged with the supply joint portion 63.

[0070] A power transmission gear train x, a pair of bearings y, two spacer collars z, etc. are provided inside the device body 13 through which the extension shaft portion 11c (drive shaft 11) penetrates, and the rotational power of the motor 12 is transmitted to the drive shaft 11 via the power transmission gear train x. A shaft female thread portion 127 corresponding to the above-mentioned connecting female thread portion 87 is formed at the end of the extension shaft portion 11c, and a connecting male screw member 92 to which a joint body 91 is attached is screwed into this shaft female thread portion 127.

[0071] On one hand, a through-hole flow path 124 is formed in the male screw-shaped shaft portion 11b, while an extended shaft center hole flow path 128 corresponding to the shaft center hole flow path 125 is formed in the extended shaft portion 11c. The extended shaft center hole flow path 128 extends at a right angle from the through-hole flow path 124 and extends to the female screw portion 127 of the shaft portion of the extended shaft portion 11c.

[0072] As a result, the upstream side of the extended shaft center hole flow path 128 communicates with the shaft center flow path 105 (axial direction hole 103) of the connecting male screw member 92 via the female screw portion 127 of the shaft portion, and the downstream side of the through-hole flow path 124 communicates with the coolant reservoir 84. The coolant flowing into the female screw portion 127 of the shaft portion from the shaft center flow path 105 reaches the coolant reservoir 84 through the extended shaft center hole flow path 128 and the through-hole flow path 124, and is supplied from the coolant reservoir 84 to the cutting grindstone 20 (annular step portion 32a).

[0073] In this case, the female screw portion 127 of the shaft portion, the extended shaft center hole flow path 128, the through-hole flow path 124, and the coolant reservoir 84 constitute the "coolant introduction mechanism" described in the claims. The female screw portion 127 of the shaft portion, the extended shaft center hole flow path 128, and the through-hole flow path 124 constitute the "introduction flow path portion" described in the claims. Furthermore, the female screw portion 127 of the shaft portion constitutes the "communication flow path" described in the claims.

[0074] As described above, according to the present embodiment, since the cutting grindstones 20, 20A, 20B are attached to the drive shaft 11 of the cutting device 10 via the device structures 15, 15A, 15B, 15C (mounting unit 14), the cutting grindstones 20, 20A, 20B having the coolant flow path 35 can be detachably and properly mounted. That is, the cutting grindstones 20, 20A, 20B can be detachably attached to the drive shaft 11 via the device structures 15, 15A, 15B, 15C in a state where coolant can be stably supplied.

Explanation of Reference Numerals

[0075] 10... Cutting device, 11... Drive shaft, 11a... Anti-rotation cut shaft portion, 11b... Male screw-shaped shaft portion, 11c... Extension shaft portion, 13... Device body, 14... Mounting unit, 15, 15A, 15B, 15C... Mounting structure, 20, 20A, 20B... Cutting grindstone, 32... Mounting hole, 32a... Annular stepped portion, 35... Cooling liquid flow path, 35a... Inlet, 40... First substrate, 41... First mounting hole, 50... Second substrate, 51... Second mounting hole, 57... Through hole, 58... Substrate internal reservoir, 61... Inner flange, 62... Lock nut, 63... Supply joint portion, 73... Clamping contact receiving portion, 74... Insertion hole, 75... First O-ring, 76... Second O-ring, 81... Nut body, 83... Clamping contact portion, 84... Cooling liquid reservoir, 85... Female screw-shaped portion, 85b... Non-threaded region, 86... Recessed flow path, 87... Connecting female screw portion, 88... Third O-ring, 91... Joint body, 92... Connecting male screw member, 93... Fourth O-ring, 94... Fifth O-ring, 111... Rotation allowance portion, 115... Annular liquid reservoir, 121... Annular groove flow path, 122... Single-character flow path, 124... Through hole flow path, 125... Axial center hole flow path, 127... Shaft portion female screw portion, 128... Extension axial center hole flow path,

Claims

1. A mounting structure for a cutting grindstone in which an inlet of a coolant flow path is formed in a hole forming portion of a mounting hole, and the coolant can be supplied during rotational driving, comprising: a drive shaft that includes a rotation preventing shaft portion provided on the apparatus body side and a male screw-shaped shaft portion protruding from the rotation preventing shaft portion, and rotates the mounted cutting grindstone; an inner flange that engages with the rotation preventing shaft portion and receives the cutting grindstone mounted on the male screw-shaped shaft portion; a lock nut that has a female screw-shaped portion screwed onto the male screw-shaped shaft portion and sandwiches and fixes the cutting grindstone between the lock nut and the inner flange; a coolant introduction mechanism configured in at least one of the drive shaft and the lock nut with the lock nut screwed onto the drive shaft, and guides the coolant supplied from a coolant supply source to the inlet; a supply joint portion having a shaft-shaped rotating portion that is fluidly connected to the coolant introduction mechanism coaxially with the drive shaft and a non-rotating member portion that is fluidly connected to the coolant supply source; the shaft-shaped rotating portion has an axial center flow path that communicates with the coolant introduction mechanism; the non-rotating member portion has an annular liquid reservoir that surrounds the shaft-shaped rotating portion and communicates with the axial center flow path from the radial direction, and a connection port portion that communicates with the annular liquid reservoir and to which the coolant supply source is connected. A mounting structure for a cutting grindstone, characterized by the above.

2. The coolant introduction mechanism is: an annular coolant reservoir configured between the lock nut and the cutting grindstone so that the inlet faces the coolant reservoir; an introduction flow path portion having an upstream side communicating with the axial center flow path and a downstream side communicating with the coolant reservoir. The mounting structure for a cutting grindstone according to claim 1, characterized by the above.

3. The introduction flow path portion is: a recessed flow path that is recessed and formed on the inner peripheral surface of the female screw-shaped portion and extends axially along the female screw-shaped portion from the coolant reservoir; a communication flow path that communicates the recessed flow path and the axial center flow path. The mounting structure for a cutting grindstone according to claim 2, characterized by the above.

4. The introduction flow path portion is: an annular groove flow path formed on the outer peripheral surface of the male screw-shaped shaft portion so as to face the coolant reservoir; a linear flow path formed on the outer peripheral surface of the male screw-shaped shaft portion and extending from the annular groove flow path to the tip of the male screw-shaped shaft portion; a communication flow path that communicates the linear flow path and the axial center flow path. The mounting structure for a cutting grindstone according to claim 2, characterized by the above.

5. The introduction flow path portion is: A radial hole flow path formed on the outer peripheral surface of the male screw-shaped shaft portion so as to face the coolant reservoir, An axial hole flow path formed in the axial center portion of the male screw-shaped shaft portion and extending from the radial hole flow path to the tip of the male screw-shaped shaft portion, The mounting structure of the cutting grindstone according to claim 2, further comprising a communication flow path that communicates the axial hole flow path with the axial center flow path.

6. The drive shaft has an extension shaft portion that is continuous with the proximal end side of the male screw-shaped shaft portion and extends through the device body to the opposite side, and the supply joint portion is attached to the extension shaft portion. The introduction flow path portion is A radial hole flow path formed on the outer peripheral surface of the male screw-shaped shaft portion so as to face the coolant reservoir, An extension shaft direction hole flow path formed in the axial center portions of the male screw-shaped shaft portion and the extension shaft portion and extending from the radial hole flow path to the tip of the extension shaft portion, The mounting structure of the cutting grindstone according to claim 2, further comprising a communication flow path that communicates the extension shaft direction hole flow path with the axial center flow path.

7. The mounting structure of the cutting grindstone according to claim 1, wherein the inner flange has a first seal member that seals between the cutting grindstone and a second seal member that seals between the male screw-shaped shaft portion.

8. The mounting structure of the cutting grindstone according to claim 1, wherein the lock nut has a third seal member that seals between the cutting grindstone.

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