JP4711752B2 - Coolant supply attachment - Google Patents

Description

  The present invention is a coolant supply that is interposed between an electric drill and a grinding bit to be attached to and detached from the power drill, and supplies the coolant to the tip of the grinding bit by pressing the tip of the grinding bit against the concrete to be drilled. It is about attachment.

  Conventionally, as this type of coolant supply attachment, an input shaft connected to the main shaft of the electric drill, an output shaft that is integrally inserted and slidable in the axial direction with respect to the input shaft, a distal end side of the input shaft, and There has been known one provided with an attachment case (attachment housing) for rotatably accommodating the base end side of the output shaft. A small hole is formed in the input shaft to guide the coolant from the outside (coolant tank) to the output shaft through the attachment case, and the shaft that communicates with the coolant channel in the bit is connected to the output shaft. An internal coolant channel is formed, and a communication hole is formed for guiding the coolant flowing in from the small hole to the in-axis coolant channel. The communication hole opens in an annular groove formed on the outer peripheral surface of the output shaft, and a pair of O-rings are mounted on the output shaft with the annular groove sandwiched in the axial direction.

When a grinding bit (diamond bit) is pressed against the concrete during drilling, the output shaft slides toward the electric drill with respect to the input shaft. And the coolant flows into the coolant flow path from the small hole through the communication hole (valve opening). That is, the sliding O-ring and the small hole constitute a valve mechanism that opens and closes the coolant channel from the small hole to the in-axis coolant channel (see Patent Document 1).
JP 2002-361626 A

  In such a concrete drilling device, when the valve mechanism is opened, it is necessary to make the pressing amount of the grinding bit equal to or greater than the thickness of the O-ring. Therefore, the stroke for opening and closing the coolant flow path becomes long, and there is a problem that the blurring of the tip of the grinding bit is increased and workability is deteriorated.

  Accordingly, an object of the present invention is to provide a coolant supply attachment that can suppress blurring of the tip of the grinding bit and that does not impair the drilling workability.

  The concrete drilling device of the present invention is interposed between a grinding bit having a coolant flow channel in the bit formed in the shaft center and an electric drill to which the grinding bit is mounted, and the tip of the grinding bit is a drilling target. In the coolant supply attachment that supplies coolant to the tip of the grinding bit being ground by pressing against the concrete, the attachment case is fixed to the drill casing of the electric drill and has a coolant introduction port for introducing the coolant A cylindrical input shaft with a bottom that is connected to the main shaft of the electric drill, communicates with the coolant introduction port and is rotatably supported by the attachment case, and an inner peripheral surface of the input shaft. It is formed at the shaft center of the output shaft and the output shaft, which is held integrally and freely slidable in the axial direction. The in-shaft coolant passage communicating with the coolant passage in the bit and the in-shaft coolant passage on the downstream side are opened by the retraction of the output shaft accompanying the pressing of the grinding bit, and the grinding bit is pushed. A flow path opening / closing means that closes when the output shaft advances due to the release, and the flow path opening / closing means is configured to freely move forward and backward from the downstream side to the valve seat constituted by a constricted portion of the in-shaft coolant flow path. It has a taper-shaped valve body that faces and a valve body support member that supports the valve body and is fixed to the input shaft.

  According to this configuration, the flow path opening / closing means includes the valve seat configured by the narrowed portion of the on-axis coolant flow path, and the tapered valve body facing the valve seat so as to freely advance and retract from the downstream side. From the closed state where the seat and valve body are in close contact, the valve body is moved slightly upstream relative to the valve seat to create a gap between the valve body and the valve seat. The coolant channel can be opened (opened). For this reason, the output shaft is slightly retracted to the electric bit side with the pressing of the grinding bit, and the valve seat is slightly retracted (separated) upstream from the valve body fixed to the input shaft by the valve body support member. By doing so, the in-shaft coolant channel can be opened. Also, in this state, the output shaft is slightly advanced to the grinding bit side as the grinding bit is released, and the valve seat is slightly advanced (closely) to the downstream side with respect to the valve body. The agent flow path can be closed. In this way, since the in-shaft coolant channel can be opened and closed by slightly moving the output shaft back and forth, the stroke of the output shaft for opening and closing the in-axis coolant channel can be shortened. Therefore, blurring at the tip of the grinding bit can be suppressed, and drilling workability is not impaired.

  In this case, it is preferable that the in-shaft coolant channel passes through the output shaft in the axial direction and is open to the bottom of the input shaft.

  According to this configuration, the coolant flows into the bottom of the input shaft via the in-shaft coolant passage. The coolant flowing into the bottom of the input shaft urges the output shaft held slidably on the inner peripheral surface of the input shaft toward the grinding bit, that is, in the closing direction, by the pressure (water pressure). For this reason, without providing an urging member such as a spring, the output shaft can be automatically advanced in the closing direction as the grinding bit is released, and the coolant flow in the shaft can be closed.

  In these cases, it is preferable that the valve body support member is formed in a rod shape, is accommodated in the in-shaft coolant passage, and the base end portion is fixed to the bottom portion of the input shaft.

  According to this structure, the whole attachment can be made into a compact structure by accommodating the valve body support member using the space in the coolant flow path in the shaft.

  In these cases, an input flange portion is formed at the distal end portion of the input shaft, an output flange portion is formed at the distal end portion of the output shaft, and the input flange portion and the output flange portion face each other with a gap. In addition, it is preferably connected by a plurality of connecting pins arranged uniformly in the circumferential direction, and the plurality of connecting pins preferably allow the output flange portion to slide in the axial direction with respect to the input flange portion.

  According to this configuration, the input flange portion and the output flange portion can be fixed to each other in the rotational direction and can be connected to each other so as to be separated from each other in the axial direction. For this reason, without requiring a keyway or the like, the output shaft can be held with respect to the input shaft so as to be integrally rotatable and slidable in the axial direction.

  In this case, it is preferable that an elastic member for biasing the valve seat relative to the valve body in the closing direction is interposed between the input flange portion and the output flange portion.

  According to this configuration, the elastic member interposed between the input flange portion and the output flange portion is appropriately deformed during the drilling operation, so that the axial vibration accompanying the drilling operation is absorbed and attenuated. Further, the elastic member can automatically advance the output shaft in the closing direction as the grinding bit is released. Therefore, noise generated during drilling work can be reduced, and the in-shaft coolant flow path can be automatically closed after the work is finished.

  Hereinafter, an embodiment of a perforating apparatus to which the present invention is applied will be described with reference to the accompanying drawings. In this drilling device, a diamond bit is attached to the tip of an electric drill via a coolant supply attachment to drill a concrete.

  As shown in FIG. 1, a drilling device 1 includes a diamond bit 2 having a diamond cutting edge 101 for grinding concrete C at the tip, an electric drill 3 as a power source for rotating the diamond bit 2, a diamond bit 2 and an electric motor. A coolant supply unit 4 having a coolant supply attachment 17 interposed between the drill 3 and a coolant recovery unit (not shown) for recovering the coolant supplied to the diamond cutting blade 101 together with the grinding powder of concrete C; The guide unit 5 holds the coolant supply attachment 17 and guides the drilling of the diamond bit 2.

  In the drilling operation, the coolant is supplied from the coolant supply unit 4 to the tip of the diamond bit 2, the diamond bit 2 is applied to a required drilling location through the guide unit 5, the diamond bit 2 is rotated by the electric drill 3, Concrete C is perforated with the diamond cutting edge 101. The coolant supplied to the tip of the diamond bit 2 is recovered by the coolant recovery unit while being mixed with the grinding powder of the concrete C.

  The electric drill 3 has a drill casing 11 and a grip portion 12 extending rearward from the drill casing 11. The drill casing 11 outputs a motor (not shown) driven by a commercial power source and the motor speed reduced. A speed reducer (not shown) is accommodated.

  Although not shown, the shaft cover 13 formed at the tip of the drill casing 11 is one of a pair of bearings (base end side) that rotatably supports an input shaft 22 (see FIG. 2) of a coolant supply attachment 17 described later. Bearing). Further, the main shaft 14 of the electric drill 3 extending from the reduction gear is formed with a concave groove having a square cross section, and a drill engaging portion 47 (described later) of the input shaft 22 is engaged therewith. Furthermore, a female screw that is screwed into an attachment case 21 (described later) of the coolant supply attachment 17 is formed on the inner peripheral surface of the tip portion of the shaft cover 13.

  The diamond bit 2 is a core bit that grinds the concrete C into a ring shape so as to leave the core portion. The diamond bit 2 holds a diamond cutting blade 101 for drilling the concrete C, a diamond cutting blade 101 at the tip, and a base end. And a shank 102 attached to the coolant supply attachment 17.

  The diamond cutting edge 101 is formed in a cylindrical shape so as to grind the concrete C so as to leave the core portion, and is formed to have a somewhat larger diameter than the shank 102.

  The shank 102 is integrally formed with a shank main body 103 having a diamond cutting edge 101 screwed to the tip thereof and a joining concave portion 104 formed in a bottomed cylindrical shape connected to the base end side of the shank main body 103. . In the joint recess 104, a joint projection 63 (see FIG. 2) of the output shaft 23 described later is fitted, and a locking groove (not shown) in which the latch pin of the joint projection 63 is locked is formed. Has been. Thereby, the diamond bit 2 is detachably attached to the coolant supply attachment 17.

  In addition, the core portion of the drilled concrete C is drawn into the axial center portion of the diamond bit 2, and an in-bit coolant channel 105 serving as a coolant channel is formed. That is, the coolant is guided from the output shaft 23 through the coolant channel 105 in the bit to the tip of the diamond cutting blade 101, while the ground core portion is relatively moved from the diamond cutting blade 101 to the inside of the bit. Guided to the coolant channel 105.

  The guide unit 5 accommodates the mounting block 111 fixed to the outer peripheral surface of the attachment case 21 of the coolant supply attachment 17 which will be described later, and the diamond cutting blade 101 of the diamond bit 2 and the abutting block 112 abutted against the concrete C. And two expansion rods 113 and 114 passed between the mounting block 111 and the abutting block 112, and a coil spring 115 wound around one of the small expansion rods 113, with the diamond bit 2 at the center. Extends forward as if hugging. Reference numeral 116 denotes a single-character grip for supporting the coolant supply attachment 17 by hand, and is attached to the attachment case 21 through the attachment block 111.

  Each of the two telescopic rods 113 and 114 has a nested structure and is configured to be telescopic. The coil spring 115 is interposed between the mounting block 111 and the abutting block 112 and urges the abutting block 112 in response to the mounting block 111. For this reason, when the diamond bit 2 protrudes from the abutting block 112 and gradually advances during the drilling operation, the two telescopic rods 113 and 114 contract against the coil spring 115. At that time, the abutting block 112 urged by the coil spring 115 always keeps being abutted against the concrete C (the edge of the perforated hole), so that the perforating work can be appropriately performed. It has become.

  Although not shown, a coolant recovery container of the coolant recovery unit or a recovery tube connected to the coolant recovery container is attached below the abutting block 112.

  The coolant supply unit 4 includes a pressurized coolant tank 16 for storing coolant such as coolant and a low boiling point solution, and a coolant interposed between the diamond bit 2 and the electric drill 3 on the same axis. The supply attachment 17 and the coolant tube 18 that connects the coolant tank 16 and the coolant supply attachment 17 are configured. As will be described in detail later, the coolant is pressurized and supplied from the coolant tank 16 to the coolant supply attachment 17 via the coolant tube 18, and in conjunction with the operation of abutting the diamond bit 2 against the wall surface of the concrete C, The coolant is supplied from the coolant supply attachment 17 through the diamond bit 2 to the tip (diamond cutting edge 101).

  As shown in FIG. 2, the coolant supply attachment 17 is connected to the attachment case 21 fixed to the drill casing 11 of the electric drill 3 and the main shaft 14 of the electric drill 3, and is rotatably supported by the attachment case 21. The input shaft 22, the output shaft 23 that is held so as to be rotatable integrally with the input shaft 22 and slidable in the axial direction, and an in-shaft coolant passage 64 formed at the axis of the output shaft 23. And a valve member 24 having a valve body 81 at the tip. Further, the output shaft 23 is urged toward the diamond bit 2 between the input flange portion 43 formed at the distal end portion of the input shaft 22 and the output flange portion 62 formed at the distal end portion of the output shaft 23. An elastic member 25 is interposed.

  As shown in FIGS. 2 and 3, the attachment case 21 is made of metal such as aluminum and has a cylindrical shape and is formed in the inside thereof so as to open to the electric drill 3 side (base end side). An inner diameter portion 31 that is continuous with the inner diameter portion 31 and an inner diameter portion 32 that is formed slightly narrower than the inner diameter portion 31 and an inner diameter portion 32 that is continuous with the inner diameter portion 32 and formed with a diameter smaller than that. 33 and a short inner diameter portion 34 that is continuous with the small inner diameter portion 33 and opens to the diamond bit 2 side (tip side) and is formed to have substantially the same diameter as the long inner diameter portion 31.

  The attachment case 21 has a male screw 35 formed on the outer peripheral surface thereof on the diamond bit 2 side, and the tip of the shaft cover 13 of the drill casing 11 is screwed to the male screw 35. Further, the short inner diameter portion 34 of the attachment case 21 is provided with a distal end side bearing 36 which is paired with the above-mentioned proximal end side bearing, and the attachment case 21 is integrated with the shaft cover 13 so as to be integrated with the base cover. The input shaft 22 is rotatably supported by the end side bearing and the front end side bearing 36.

  Further, a connection hole 37 (coolant introduction port) communicating with the small inner diameter portion 33 is opened on the outer peripheral surface of the attachment case 21, and the coolant tube 18 is connected (screwed) to the connection hole 37. Yes. Further, seal packings 51 and 52 are disposed at both ends in the axial direction of the small inner diameter portion 33 (details will be described later).

  As shown in FIGS. 2 and 4, the input shaft 22 is made of a metal such as stainless steel, and is connected to the main shaft connecting portion 41 connected to the main shaft 14 of the electric drill 3 and to the diamond bit 2 side of the main shaft connecting portion 41. A cylindrical portion 42 which is formed in a cylindrical shape with a bottom and which holds the output shaft 23 so as to be integrally rotatable and slidable in the axial direction on an inner peripheral surface thereof, and an input flange portion 43 formed at the tip of the cylindrical portion 42 And are integrally formed.

  The main shaft connecting portion 41 is integrally formed by a connecting shaft portion 46 that is continuous from the cylindrical portion 42 and is pivotally supported by the proximal end bearing, and a drill engaging portion 47 having a square cross section that is continuous with the connecting shaft portion 46. The engaging portion 47 engages with the concave groove formed on the main shaft 14 of the electric drill 3 with one touch.

  The cylindrical portion 42 is formed in substantially the same dimension as the attachment case 21 in the axial direction, and the outer peripheral surface thereof is formed slightly smaller in diameter than the small inner diameter portion 33 of the attachment case 21. In addition, the inner peripheral surface of the cylindrical portion 42 constitutes a cylinder interior 44 into which the output shaft 23 is inserted with a slidable tolerance.

  A pair of seal packings 51 and 52 disposed at both axial ends of the small inner diameter portion 33 of the attachment case 21 seals between the outer peripheral surface of the cylindrical portion 42 and the inner peripheral surface of the small inner diameter portion 33. An annular outer coolant reservoir 53 is formed between the outer peripheral surface of the cylindrical portion 42 and the inner peripheral surface of the small inner diameter portion 33. The outer coolant reservoir 53 communicates with the connection hole 37 from the radially outer side, and communicates a radial flow path 56 described later from the radially inner side.

  An annular spacer 54 is interposed between the seal packing 51 disposed on the diamond bit 2 side of the small inner diameter portion 33 and the front end side bearing 36 accommodated in the small inner diameter portion 33. A shallow groove 54 a is formed on the surface of the spacer 54 on the diamond bit 2 side so as not to contact the inner race of the tip side bearing 36. Further, an annular packing retainer 55 for screwing the seal packing 52 disposed on the electric drill 3 side of the small inner diameter portion 33 in the axial direction is screwed into the inner inner diameter portion 32.

  On the outer peripheral surface of the cylindrical portion 42, a pair of radial flow paths 56 communicating with the cylinder interior 44 are formed at positions 180 ° symmetrical to the outer peripheral surface. A fixing screw hole 58 for fixing a base end of a valve body support portion 82 (described later) of the valve member 24 is formed in the bottom portion 57 of the cylinder interior 44.

  The input flange portion 43 functions as a stopper for the front end side bearing 36, but the input flange portion 43 is arranged so that the surface of the input flange portion 43 on the electric drill 3 side contacts only the inner race of the front end side bearing 36. As for the surface at the side of the electric drill 3, the peripheral part is formed thinly via the step part. Further, the input flange portion 43 is opposed to an output flange portion 62 of the output shaft 23 to be described later with a gap, and the input flange portion 43 has four input side connection holes 59 that are equally arranged in the circumferential direction. Is formed. Each input-side connecting hole 59 is press-fitted with a connecting pin 77 for connecting to the output flange portion 62 (details will be described later).

  As shown in FIGS. 2 and 5, the output shaft 23 is made of metal such as stainless steel, and the output shaft main body 61 inserted into the cylindrical portion 42 (cylinder interior 44) of the input shaft 22, and the output shaft main body 61. The output flange 62 connected to the diamond bit 2 side and the joint convex 63 connected to the diamond bit 2 side of the output flange 62 are integrally formed, and the diamond bit 2 is connected to the joint convex 63. It has become so. Further, an axial coolant channel 64 communicating with the above-described coolant channel 105 in the bit is formed in the shaft center of the output shaft 23 so as to penetrate downstream. That is, the in-shaft coolant channel 64 is open to the bottom 57 of the cylinder interior 44 of the input shaft 22.

  The output shaft main body 61 is formed to be slightly longer in the axial direction than the cylinder interior 44 of the input shaft 22, and its outer peripheral surface is formed to have substantially the same diameter as the cylinder interior 44 (with a slidable dimensional tolerance). Yes. In addition, an annular groove 66 is formed in a substantially intermediate portion in the axial direction of the outer peripheral surface of the output shaft main body 61. The annular groove 66 has a diameter in the axial coolant channel 64 at a 180 ° symmetrical position of the outer peripheral surface. A pair of communication holes 67 communicating from the direction are formed.

  An annular inner coolant reservoir 68 is formed between the outer peripheral surface of the annular groove 66 and the inner peripheral surface of the cylindrical portion 42, and the inner coolant reservoir 68 is formed on the inner coolant reservoir 68 from the radially outer side. A pair of radial flow paths 56 communicate with each other, and a pair of communication holes 67 communicate with each other from the radially inner side. Therefore, the in-shaft coolant channel 64 communicates with the pair of radial channels 56 via the pair of communication holes 67 and the inner coolant reservoir 68 on the upstream side. That is, the coolant flow through the in-shaft coolant channel 64 in order from the upstream side through the connection hole 37, the outer coolant reservoir 53, the radial flow channel 56, the inner coolant reservoir 68, and the communication hole 67. A coolant is supplied from the tank 16.

  Since the in-shaft coolant channel 64 is open to the bottom 57 of the input shaft 22 as described above, the coolant supplied to the in-axis coolant channel 64 is cooled in the bit communicating with the downstream side. It flows into the agent flow path 105 and also flows into the bottom 57 of the input shaft 22. The coolant that has flowed into the bottom 57 of the input shaft 22 urges (presses) the output shaft 23 slidably held on the inner peripheral surface of the input shaft 22 toward the diamond bit 2 by its pressure. For this reason, although details will be described later, when the pressing of the diamond bit 2 is released after the drilling operation is completed, the output shaft 23 can be automatically advanced to the diamond bit 2 side, and the in-axis coolant channel 64 is automatically set. Can be obstructed.

  Note that the diamond bit in the annular groove 66 prevents the coolant flowing into the bottom 57 of the input shaft 22 from leaking from the gap between the outer peripheral surface of the output shaft main body 61 and the inner peripheral surface of the cylindrical portion 42 to the diamond bit 2 side. An O-ring 69 is mounted on the second side.

  The in-shaft coolant channel 64 includes a narrowed portion 72 formed in the vicinity of the downstream end thereof, an upstream portion 73 connected to the upstream side from the narrowed portion 72, and a downstream portion 74 connected to the downstream side from the narrowed portion 72. The narrowed portion 72 is formed with a smaller diameter than the upstream portion 73 and the downstream portion 74, and the downstream portion 74 is formed with a slightly smaller diameter than the upstream portion 73. Although the details will be described later, the narrowed portion 72 functions as a valve seat for the valve body 81 of the valve member 24.

  As in the case of the input flange portion 43, the output flange portion 62 is formed with four output side connection holes 76 that are equally arranged in the circumferential direction. A connecting pin 77 having a countersunk head is inserted into each output side connecting hole 76 and each corresponding input side connecting hole 59 from the diamond bit 2 side. The four connecting pins 77 connect the input flange portion 43 and the output flange portion 62 and allow the output flange portion 62 to slide in the axial direction with respect to the input flange portion 43.

  Thereby, the input flange part 43 and the output flange part 62 can be connected to each other so as to be separable from each other in the axial direction while being fixed in the rotational direction. For this reason, with a simple configuration, the output shaft 23 can be held with respect to the input shaft 22 so as to be integrally rotatable and slidable in the axial direction. An elastic member 25 described later is also interposed between the input flange portion 43 and the output flange portion 62 with the four connecting pins 77 penetrating therethrough.

  Although not shown in the figure, a locking pin is implanted in the bonding convex portion 63, and the bonding convex portion 63 is connected to the bonding concave portion 104 by the locking pin and a locking groove formed in the bonding concave portion 104 of the diamond bit 2. It is connected in the retaining state.

  As the diamond bit 2 is pressed against the concrete C, the output shaft 23 connected to the diamond bit 2 is guided by the inner peripheral surface of the cylindrical portion 42 of the input shaft 22 so that the electric drill 3 side Retreat to. As the diamond bit 2 is released, the output shaft 23 is urged by the coolant flowing into the bottom 57 of the input shaft 22 and the elastic member 25 described later, and advances toward the diamond bit 2 side.

  As shown in FIGS. 2 and 6, the valve member 24 is made of a metal such as stainless steel, and includes a valve body 81 accommodated in the downstream portion 74 of the in-shaft coolant passage 64, and an in-shaft from the valve body 81. In the coolant flow path 64, it is comprised integrally with the valve body support part 82 extended to the electric drill side.

  The valve body support portion 82 is formed to be slightly smaller in diameter than the narrowed portion 72 of the in-axis coolant flow path 64, and is connected to the valve body 81 on the distal end side, and a proximal end portion on which a male screw is formed. The screw 86 is fixed to the input shaft 22 by being screwed into a fixing screw hole 58 formed in the bottom portion 57 of the input shaft 22. The valve body 81 is connected to the distal end side of the valve body support portion 82, is tapered to the electric drill 3 side, is connected to the diamond bit 2 side of the taper portion 87, and is connected to the axial coolant passage 64. The valve tip 88 is formed with a diameter smaller than the upstream portion 73 and larger than the narrowed portion 72.

  And the taper part 87 of the valve body 81 and the downstream opening part 75 from the constriction part 72 are formed so that it may contact | adhere without a gap, and when both are in a close state, the axial coolant flow path 64 Is closed (closed). Further, the valve body 81 is slightly moved downstream with respect to the stenosis part 72 from the closed state where the taper part 87 of the valve body 81 and the downstream side opening part 75 from the stenosis part 72 are in close contact with each other. However, a gap is generated between the tapered portion 87 and the downstream opening 75, and the in-axis coolant channel 64 is opened (opened). Note that it is preferable to chamfer the peripheral edge of the downstream opening 75 in a complementary shape to the taper 87 in order to increase the close contact between the taper 87 and the downstream opening 75.

  For this reason, the output shaft 23 is slightly retracted toward the electric drill 3 as the diamond bit 2 is pressed, and the constricted portion 72 is electrically drilled with respect to the valve body 81 fixed to the input shaft 22 by the valve body support portion 82. By slightly retracting (separating) the third side (opening direction), the in-axis coolant channel 64 can be opened. Further, from this state, the output shaft 23 is slightly advanced toward the diamond bit 2 (in the closing direction) with the release of the diamond bit 2 and the constricted portion 72 is slightly advanced toward the downstream side with respect to the valve body 81 ( The in-axis coolant channel 64 can be closed by close contact. That is, the narrowed portion 72 (valve seat) of the in-shaft coolant passage 64, the valve body 81 of the valve member 24, and the valve body support portion 82 constitute the flow path opening / closing means described in the claims. Has been.

  As described above, since the in-shaft coolant passage 64 can be opened and closed by slightly moving the output shaft 23 forward and backward, the stroke of the output shaft 23 for opening and closing the in-shaft coolant passage 64 is shortened. Can do.

  The valve member 24 also functions as a retainer for the output shaft 23. That is, the output shaft 23 is restricted from moving toward the diamond bit 2 by the downstream opening 75 of the constricted portion 72 of the in-axis coolant channel 64 coming into contact with the tapered portion 87 of the valve body 81. .

  The coolant supply attachment 17 configured as described above inserts the input shaft 22 into the attachment case 21 from the diamond bit 2 side, and a cylindrical portion 42 (described later) of the input shaft 22 formed in a bottomed cylindrical shape. Then, the output shaft 23 is inserted from the diamond bit 2 side, and then, the valve member 24 is inserted from the diamond bit 2 side into the in-axis coolant flow path 64 of the output shaft 23 and the base end portion 86 of the input shaft 22 is It is assembled by fixing to the bottom 57 (described later). Further, the elastic member 25 is interposed between the input flange portion 43 and the output flange portion 62.

  As shown in FIGS. 2 and 7, the elastic member 25 is made of synthetic rubber or the like, and is supported by the annular base 91 that is in contact with the surface of the output flange 62 on the electric drill 3 side, and the annular base 91. It is formed integrally with an annular convex portion 92 that contacts the surface of the flange portion 43 on the diamond bit 2 side.

  The annular convex portion 92 is formed in a trapezoidal cross section, and has an outer edge contact portion 96 positioned on the radially outer side, and an inclined portion whose upper surface is inclined so as to become thinner toward the radially inner side. It consists of 97. Further, the annular convex portion 92 is formed with groove portions 98 extending from the inner edge to the outer edge at four locations at equal intervals in the circumferential direction. The annular base 91 is formed with four insertion holes 99 through which the four connecting pins 77 are inserted, corresponding to the positions where the four groove portions 98 are formed. That is, the elastic member 25 is attached between the input flange portion 43 and the output flange portion 62 by the four connecting pins 77 that are respectively inserted through the four insertion holes 99.

  Further, when the output flange portion 62 slides toward the electric drill 3 with the pressing of the diamond bit 2, the outer edge contact portion 96 of the annular convex portion 92 and the input flange portion 43 abut, and the annular convex portion 92 is outward. It bends as it expands. At this time, since the four groove portions 98 are formed in the annular convex portion 92, the annular convex portion 92 is easily spread outward.

  When the drilling operation is performed in this state, the elastic member 25 is appropriately deformed, so that the axial vibration accompanying the drilling operation is absorbed and attenuated. Therefore, noise generated during drilling can be reduced.

  Further, when the pressing of the diamond bit 2 is released, the output flange portion 62 is urged toward the diamond bit 2 side by the bent annular convex portion 92 trying to return to the original shape. For this reason, the output shaft 23 can be automatically advanced to the diamond bit 2 side (blocking direction) with the release of the pressing of the diamond bit 2 after the drilling operation is completed, and the in-axis coolant channel 64 It can be closed automatically.

  As described above, the output shaft 23 is also urged to the diamond bit 2 side by the pressure of the coolant flowing into the bottom 57 of the input shaft 22, and even if there is no urging force by the elastic member 25, As the diamond bit 2 is released, the output shaft can be automatically advanced to the diamond bit 2 side.

  As described above, according to the coolant supply attachment 17 of the present embodiment, the stroke of the output shaft 23 for opening and closing the in-axis coolant flow path 64 can be shortened, and the tip of the diamond bit 2 can be shaken. It can be suppressed and does not impair the drilling workability.

It is an external view of the perforation apparatus concerning one embodiment of the present invention. It is a structural diagram of the coolant supply attachment of the drilling device. It is sectional drawing of the attachment case of a coolant supply attachment. It is a top view of the input shaft of a coolant supply attachment. It is a top view of the output shaft of a coolant supply attachment. It is a top view of the valve member of a coolant supply attachment. (A) is a top view of the elastic member of a coolant supply attachment, (b) is sectional drawing of the elastic member of a coolant supply attachment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Diamond bit 3 ... Electric drill 11 ... Drill casing 14 ... Main shaft 17 ... Coolant supply attachment 21 ... Attachment case 22 ... Input shaft 23 ... Output shaft 25 ... Elastic member 37 ... Connection hole 43 ... Input flange part 56 ... Radial direction Flow path 57 ... Bottom 62 ... Output flange part 64 ... In-shaft coolant flow path 72 ... Narrowing part 77 ... Connecting pin 81 ... Valve body 82 ... Valve body support part 88 ... Base end part 105 ... In-bit coolant flow path C …concrete

Claims (5)

It is interposed between a grinding bit with a coolant flow channel in the bit center and an electric drill to which the grinding bit is mounted, and the tip of the grinding bit is pressed against the concrete to be drilled to perform grinding. In the coolant supply attachment for supplying coolant to the tip of the grinding bit of
An attachment case that is fixed to the drill casing of the electric drill and has a coolant introduction port for introducing a coolant,
A bottomed cylindrical input shaft connected to the main shaft of the electric drill and having a radial flow path communicating with the coolant introduction port and rotatably supported by the attachment case;
An output shaft that is held on the inner peripheral surface of the input shaft so as to be rotatable integrally and slidable in the axial direction, and the grinding bit is mounted on the tip portion;
An in-shaft coolant passage formed at the axis of the output shaft, communicating with the radial passage on the upstream side and communicating with the coolant passage on the downstream side;
Channel opening / closing means that opens the coolant channel in the shaft by retreating the output shaft accompanying pressing of the grinding bit and closes it by the advancement of the output shaft accompanying release of pressing of the grinding bit;
The channel opening / closing means includes
A valve seat constituted by a constricted portion of the in-axis coolant flow path;
A tapered valve body facing the valve seat from the downstream side so as to freely advance and retract;
A valve body support member that supports the valve body and is fixed to the input shaft;
A coolant supply attachment, comprising:   2. The coolant supply attachment according to claim 1, wherein the coolant flow path in the shaft passes through the output shaft in the axial direction and is open to a bottom portion of the input shaft.   The valve body support member is formed in a rod shape, is housed in the in-shaft coolant passage, and has a base end fixed to the bottom of the input shaft. The coolant supply attachment as described. An input flange portion is formed at the tip of the input shaft,
An output flange portion is formed at the tip of the output shaft,
The input flange portion and the output flange portion are connected by a plurality of connecting pins that face each other with a gap and are arranged uniformly in the circumferential direction,
4. The coolant supply attachment according to claim 1, wherein the plurality of connecting pins allow the output flange portion to slide in an axial direction with respect to the input flange portion. 5.   The elastic member which urges | biases the said valve seat with respect to the said valve body in the obstruction | occlusion direction is interposed between the said input flange part and the said output flange part. The coolant supply attachment as described.

Images