JP5465122B2 - Anti-sway mechanism - Google Patents

Description

  The present invention relates to an anti-vibration mechanism that suppresses vibration due to rotation of a drill bit including a cutting blade and a shank mounted on an electric drill.

Conventionally, a coolant supply attachment attached to an electric drill, a drill bit attached to the coolant supply attachment, and a guide attachment that is attached to the electric drill and guides drilling are provided, and a drill is attached to the tip of the guide attachment. There has been known a perforating apparatus having a dust seal (abutting rubber ring) through which a bit is inserted and provided with a nose block (abutting block) that abuts against an object to be perforated (see Patent Document 1).
In this drilling device, when the nose block is pressed against an object to be drilled such as concrete or tile during drilling, the tip of the dust seal slightly protruding from the butting side is in close contact with the concrete, and the pressing is maintained. Thus, the rotating drill bit protrudes from the dust seal, and the drilling target is drilled.

JP 2002-361626 A

  However, in the drilling device described above, the drill bit mounted on the drill bit cannot be properly supported due to wear or deterioration of the sealant inside the coolant supply attachment, and the drill bit rotates to the tip of the drill bit. There was a problem that shake occurred. In this case, the insertion portion of the drill bit of the dust seal is significantly worn and damaged, and the dust seal must be frequently replaced. In addition, there is a problem that accurate drilling to a desired drilling start position cannot be performed, and the finish of the hole opening deteriorates due to enlargement of the hole opening that has been drilled or surface defects such as concrete or tile that is a drilling target. there were.

  It is an object of the present invention to provide an anti-skid mechanism that can effectively suppress vibration due to rotation of a drill bit mounted on an electric drill.

The anti-skid mechanism of the present invention is an anti-skid mechanism that suppresses vibration caused by rotation of a drill bit comprising a cutting blade and a shank attached to an electric drill that is hand-held for drilling work, and is attached to the electric drill. , is fixed to the distal end of the guide attachments for guiding the drilling of the drill bit, and abutted nose block puncture hole object, it provided the nose block, rotatably shank and slidably supported in the axial direction A bearing member , the bearing member has a through-hole in which the drill bit penetrates in the axial direction and both openings are chamfered, and the nose block includes a block body, a dust seal formed of an elastic material, The dust seal includes a bottomed cylindrical cylindrical portion mounted on the inner surface of the block main body, and a horn portion that is in close contact with the perforation edge of the object to be perforated. The bottom, an insertion hole is formed the drill bit is inserted, the bearing member is characterized by being arranged so as to be in close contact with the bottom of the cylindrical portion.

According to this configuration, the drill bit is rotatably supported by the bearing member provided on the nose block while being mounted on the electric drill and at the tip of the shank. That is, the drill bit is positioned at the drilling start position of the drilling target object through the nose block that is in contact with the drilling target object. Further, since the shank of the drill bit and the bearing member are slidably engaged with each other in the axial direction, the drilling is guided in a state where rotational runout is suppressed. As a result, the rotational runout on the tip side of the drill bit can be effectively suppressed, so that accurate drilling to a desired position can be performed, and a good finish with no defects on the surface of concrete, tile, etc. Holes can be formed.
Furthermore, since each opening of the through hole of the bearing member is chamfered, the contact area between the inner surface of the through hole and the shank is reduced, and the rotational resistance and sliding resistance are reduced without impairing the function as a bearing. . Moreover, it becomes easy to insert a drill bit. Thereby, attachment of the drill bit which is an initial operation | work can be performed smoothly. Furthermore, even if the drill bit is shaken or bent, it is possible to prevent the through-hole and each opening thereof from being damaged due to contact with the drill bit.

  In this case, the bearing member is preferably screwed into an insertion opening formed in the nose block so that the drill bit can be inserted.

  According to this configuration, the bearing member can be securely fixed to the nose block in a desired posture. Thereby, the rotational runout of the drill bit can be suppressed and the rotational accuracy can be improved. Also, the bearing member (or nose block) can be easily replaced.

  In this case, it is preferable that the bearing member is fixed by being fitted into an insertion opening formed in the nose block so that the drill bit can be inserted.

  In this case, it is preferable that an elastic member is provided on the outer peripheral surface of the bearing member.

According to these configurations, the bearing member can be easily fixed to the nose block in a desired posture. As a result, it is possible to suppress the runout of the drill bit and to easily replace the bearing member.
Further, since the elastic member interposed on the outer peripheral surface of the bearing member is in close contact with the inner peripheral surface of the insertion opening of the nose block, the bearing member is fixed in a desired posture within the insertion opening.

  In this case, the bearing member preferably faces the insertion opening formed in the nose block so that the drill bit can be inserted, and is formed integrally with the nose block.

  According to this configuration, the nose block and the bearing member can be fixed in a desired positional relationship. Thereby, the rotational runout of the drill bit can be effectively suppressed.

In this case, it is preferable that the drill bit is a diamond core bit, and the dust seal is configured to be able to collect the coolant supplied via the drill bit.

  According to this configuration, the perforated portion of the object to be perforated is sealed with the dust seal. For this reason, the coolant supplied from the drill bit can be collected together with the dust during the drilling operation, and does not contaminate the work site. Note that the coolant can be recovered by, for example, sucking and recovering the coolant to an external coolant recovery device. Further, since the bearing member is provided in close contact with the dust seal, it is possible to effectively suppress the rotational runout of the drill bit within the dust seal.

  In this case, the bearing member is preferably formed integrally with the dust seal.

  According to this configuration, the nose block and the bearing member can be fixed in a desired positional relationship. Thereby, the rotational runout of the drill bit can be effectively suppressed. Moreover, the exchange of the dust seal and the exchange of the bearing member can be performed simultaneously.

  In this case, the bearing member is preferably composed of a sliding bearing.

  In this case, the sliding bearing is preferably made of any one of ceramics, hard resin, and bearing alloy.

  According to these configurations, the rotational resistance and sliding resistance between the bearing member (sliding bearing) and the drill bit can be reduced. Thereby, smooth rotation of a drill bit is realizable. Further, durability can be provided against wear of the bearing member (sliding bearing) due to contact with the drill bit (shank), and the replacement frequency of the bearing member can be reduced.

  In this case, the bearing member is preferably composed of a ball bearing.

  According to this configuration, smooth rotation of the drill bit can be ensured.

It is the external view which showed typically the punching apparatus which concerns on 1st Embodiment. It is sectional drawing which showed the valve closing state (a) and the valve opening state (b) in a coolant supply attachment. It is a three-view figure of an electric drill and a guide attachment. It is the front view and side view of a nose block. It is the perspective view (a) of a dust seal, and sectional drawing (b) of a nose block, a dust seal, and a bearing member at the time of pressing a nose block against a drilling target object. It is the top view (a), sectional drawing (b), and bottom view (c) of a bearing member. It is sectional drawing (a) of the bearing member etc. which concern on 2nd Embodiment, and sectional drawing (b), (c) of the bearing member etc. which concern on the modification. It is sectional drawing (a), such as a bearing member concerning a 3rd embodiment, sectional drawing (b), such as a bearing member concerning a 4th embodiment, and sectional drawing (c), such as a bearing member concerning a 5th embodiment.

  Hereinafter, with reference to the accompanying drawings, a perforation apparatus including a swing prevention mechanism according to an embodiment of the present invention will be described. In this drilling device, a guide attachment for guiding drilling is attached to an electric drill, and a drilling operation is performed on a wall surface made of concrete, tile, stone, or the like.

  As shown in FIG. 1, the drilling apparatus 1 uses a wall surface made of concrete, tile, or the like as a drilling object C, and rotates the drill bit 2 that performs wet drilling at a predetermined position of the drilling object C, and the drill bit 2. Electric drill 3, coolant supply attachment 4 interposed between drill bit 2 and electric drill 3, guide attachment 5 that is abutted against drilling object C and guides drilling of electric drill 3, and coolant A coolant supply means 6 for supplying a coolant to the drill bit 2 via the supply attachment 4; and a coolant recovery means 7 for sucking and collecting the coolant supplied to the drill bit 2 via the guide attachment 5. I have.

  The coolant supply means 6 includes a pressure feeding device 6 a that feeds the coolant from the supply tank 6 b storing the coolant to the drill bit 2. The coolant recovery means 7 includes a suction pump 7a for sucking the coolant supplied to the drill bit 2 together with the grinding powder (dust) of the drilling object C, and a recovery tank 7b for discarding and storing the coolant mixed with dust. It is equipped with. In addition, it is preferable to use what mixed alcohol in order to accelerate | stimulate the drying (vaporization) after a work as a coolant.

  A supply tube 6c connected to the coolant supply means 6 is connected to the base side of the coolant supply attachment 4. When drilling by the drill bit 2 is started, the supply tube 6c and the coolant supply attachment are supplied from the coolant supply means 6. 4, the coolant is supplied to the drill bit 2. Further, a recovery tube 7c connected to the coolant recovery means 7 is connected to the distal end side of the guide attachment 5, and the coolant recovery means 7 is subject to drilling of the coolant supplied to the drill bit 2 via the recovery tube 7c. Suction and collected together with grinding powder (dust) of object C.

  In the drilling operation, the operator supports the electric drill 3 by hand, the tip of the drill bit 2 (cutting blade 11) is applied to the required drilling location of the drilling object C through the guide attachment 5, and the drill body 15 drills the drill bit. 2 is rotated to form a hole with a predetermined depth in the drilling object C. At this time, the coolant pressurized and supplied from the coolant supply means 6 to the coolant supply attachment 4 is linked from the coolant supply attachment 4 to the drill bit 2 in conjunction with the operation of abutting the cutting blade 11 against the drilling object C. And is supplied to the cutting blade 11. In addition, the coolant supplied to the cutting blade 11 is recovered by the coolant recovery means 7 from the tip of the guide attachment 5 in a state of being mixed with the grinding powder of the drilling object C.

  The drill bit 2 is a diamond core bit that grinds the drilling object C into a ring shape so as to leave the core part. The drill bit 2 has a cutting edge 11 (diamond cutting blade) for drilling the drilling object C and a tip at the tip. A shank 12 that holds the blade 11 and is attached to the coolant supply attachment 4 at the base end. In the axial center portion of the drill bit 2, a core piece of the drilled object C is called in and an in-bit channel 13 serving as a coolant channel is formed. The coolant is guided to the tip of the cutting edge 11 through the channel 13 in the bit, while the ground core piece of the drilled object C is relatively guided from the cutting blade 11 to the channel 13 in the bit. . In the following description, the drilling direction for the drilling object C is defined as the front (front side), and the opposite direction is defined as the rear (rear side).

  The cutting blade 11 is formed in a cylindrical shape so as to grind the drilling object C so as to leave the core portion, and is formed to have a somewhat larger diameter than the shank 12. As for the shank 12, the cutting blade 11 is fixed to the front-end part, and the cylindrical junction recessed part 14 is formed in the back end part. The drill bit 2 is attached to the coolant supply attachment 4 so as to be detachable from the output shaft 22 at the joint recess 14.

  The electric drill 3 includes a drill body 15 in which a motor driven by a common power source and a speed reducer (not shown) that decelerates and outputs the rotation of the motor are housed in a motor housing 16, and a grip portion extending rearward from the drill body 15 17. Further, a guide holder 31 (details will be described later) on which a rear end portion of the guide attachment 5 is fixed is formed on the front portion of the drill body 15 so as to protrude. Furthermore, a single character grip G for supporting the electric drill 3 by hand is attached to the front portion of the drill body 15. The grip portion 17 is provided with a trigger switch SW that controls the start / stop of driving by the operator. The main shaft 18 extending from the speed reducer is connected to an input shaft 21 of a coolant supply attachment 4 described later at the front end of the drill body 15.

  As shown in FIG. 2, the coolant supply attachment 4 has a cylindrical appearance, is attached to the drill body 15 (motor housing 16), and has an attachment case having a coolant introduction port 25 to which the supply tube 6c is connected. 20, an input shaft 21 that is rotatably supported by the attachment case 20 and to which the main shaft 18 of the drill body 15 is connected, and is rotatably held integrally with the input shaft 21 and slidable in the axial direction. The output shaft 22 formed in the center of the output shaft flow passage 22a communicating with the above-described bit internal flow passage 13, and the pressurization flow passage 23 formed in the gap between the input shaft 21 and the output shaft 22 and the output shaft And a valve mechanism 24 that performs communication or shielding with the flow path 22a.

  A front bearing 26 and a rear bearing 27 (both ball bearings) that rotatably support the input shaft 21 are fitted in front of and behind the attachment case 20 in a state of being prevented from coming off. A pair of seal packings 28 are disposed between the front bearing 26 and the rear bearing 27, and an annular coolant reservoir 29 is provided between the inner peripheral surface of the attachment case 20 and the outer peripheral surface of the input shaft 21. Is formed liquid-tight. The coolant reservoir 29 communicates with a coolant introduction port 25 for introducing the coolant.

The input shaft 21 is connected to the main shaft 18 of the drill body 15 and is rotatably supported by a front bearing 26 and a rear bearing 27.
The output shaft 22 is inserted into the shaft center of the input shaft 21 with a slidable dimensional tolerance, and is attached to the input shaft 21 so as to be integrally rotatable and slidable in the axial direction. A bit mounting portion 22b is provided at the front end (front end) of the output shaft 22, and a joint recess 14 formed at the rear end portion of the shank 12 of the drill bit 2 is screwed into the bit mounting portion 22b. An output shaft flow path 22 a formed at the axis of the output shaft 22 communicates the pressurization flow path 23 and the bit internal flow path 13.

  As described above, the pressurizing flow path 23 through which the coolant flows is formed in the gap between the input shaft 21 and the output shaft 22. The coolant supplied from the coolant supply means 6 via the supply tube 6 c is supplied to the coolant introduction port 25, the coolant reservoir 29, the pressurizing flow path 23, the output shaft flow path 22 a, and the bit internal flow path 13. Flow is supplied to the cutting edge 11 at the downstream end (front end) (see FIG. 2B).

  The valve mechanism 24 includes a pair of O-rings 24 a (valve bodies) fitted to the output shaft 22 and a valve seat 24 b formed at the distal end portion of the input shaft 21. The pair of O-rings 24a is made of an elastic material such as rubber, and is disposed at a communication portion between the pressurizing flow path 23 and the output shaft flow path 22a.

During the drilling operation, when the tip of the drill bit 2 (the cutting edge 11) is pressed against the drilling object C, the output shaft 22 moves backward relative to the input shaft 21. Then, the valve mechanism 24 is opened, and the coolant is supplied from the coolant supply means 6 to the in-bit flow path 13 via the supply tube 6c and the coolant supply attachment 4 (see FIG. 2B).
On the other hand, after the drilling operation is completed or before the drilling operation, the output shaft 22 moves forward relative to the input shaft 21 by the pressure of the coolant introduced into the pressurizing flow path 23, and the valve mechanism 24 is closed. Then, the supply of the coolant to the in-bit channel 13 is stopped (see FIG. 2A).

  Next, the guide attachment 5 will be described with reference to FIGS. 1 and 3. The guide attachment 5 includes a pair of guide holders 31 that are formed to protrude from the upper and left ends of the front end of the drill body 15, one end fixed to each guide holder 31, a slide guide 32 that extends forward, and a slide guide A nose block 41 and a bearing member 42 attached to the tip of 32, and an anti-vibration mechanism 33 that suppresses vibration due to rotation of the drill bit 2. The slide guide 32 and the drill bit 2 are located in the middle of the left and right slide guides 32 and extend forward in parallel with each other.

  The slide guide 32 guides the sliding of the nose block 41 in the front-rear direction with respect to the electric drill 3 (guide holder 31), and a first slide guide 34 having a function of adjusting the drilling depth (on the right side in FIG. 3). ), A second slide guide 35 in which the nose block 41 regulates the forward end position (left side in FIG. 3), and a pair of coil springs 36 provided so as to be wound around the first slide guide 34 and the second slide guide 35, respectively. And is composed of.

  The first slide guide 34 is supported at the front end by a first guide tube 34a fixed to a guide fixing portion 44 (described later) of the nose block 41, and at the rear end by a first guide holder 31 supported by the guide holder 31 described above. The first guide rod 34b is slidably connected to the first guide cylinder 34a in a nested manner.

  The first guide rod 34b is fixed to the guide holder 31 with a bolt, and the position of the first guide rod 34b in the front-rear direction can be adjusted by loosening the bolt. For this reason, a desired perforation depth can be set by matching the rear end of the first guide rod 34 b extending rearward from the guide holder 31 with the scale of the scale plate 34 c attached to the motor housing 16. .

  The second slide guide 35 is configured to be point-symmetric with the first slide guide 34, and the second guide tube 35a supported by the guide holder 31 at the rear end and the front end as described above. A second guide rod 35b fixed to a guide fixing portion 44 (to be described later) of the nose block 41, and the second guide rod 35b is slidably connected to the second guide cylinder 35a in a nested manner. Has been. The first slide guide 34 and the first slide guide 34 may be disposed symmetrically.

  Next, each coil spring 36 abuts on the guide holder 31 at the rear end and abuts on each guide fixing portion 44 at the front end to function as a compression spring. That is, each coil spring 36 receives the guide holder 31 and urges the nose block 41 forward. The coil spring 36 may be provided only on either the first slide guide 34 or the second slide guide 35.

  The drilling operation is performed with the operator holding the electric drill 3 by hand. When the drill bit 2 is gradually advanced while being guided by the slide guide 32 along with the drilling, the slide guide 32 is moved to a pair of coil springs. The nose block 41 urged by the pair of coil springs 36 is always kept in contact with the drilling object C. When the drilling reaches the adjusted drilling depth, the tip end portion of the first guide rod 34b hits against the contact member (not shown) and the drilling is restricted. When the drilling operation is completed in this way, the operator removes the force. Then, the spring force of the pair of coil springs 36 acts, and the drill bit 2 is pulled straight out of the hole while being guided by the slide guide 32.

  Next, with reference to FIG. 3 to FIG. As shown in FIGS. 3 and 4, the bracing mechanism 33 is provided on the nose block 41 that is abutted against the drilling object C and the nose block 41, and the shank 12 of the drill bit 2 is rotatable and is axial. And a bearing member 42 that is slidably supported.

  The nose block 41 includes an abutment guide portion 43 in which an insertion opening 51 through which a distal end portion of the drill bit 2 faces is formed at the center, a pair of guide fixing portions 44 to which a front end portion of the slide guide 32 is fixed, and an insertion And a dust seal 45 attached to the opening 51. The “block body” in the claims refers to the abutting guide portion 43.

  The abutting guide part 43 is integrally formed by a plate part 52 formed in a plate shape that abuts against the perforation object C, and a block part 53 that protrudes rearward from the center of the width of the plate part 52 in a block shape. Yes. The plate portion 52 has a horizontally long rectangle, and a surface (abutting surface S) that abuts against the perforated object C is formed of an elastic material such as rubber (preferably fluororubber). A contact sheet 54 is attached. The abutting surface S and the axial direction of the drill bit 2 are orthogonal to each other. When the abutment guide portion 43 is abutted against the drilling object C, the drill bit 2 faces the drilling object C at a right angle. (See FIG. 1).

  When performing the drilling operation, the operator abuts the nose block 41 against the drilling object C and brings the contact surface S of the abutting guide portion 43 into surface contact with the surface of the drilling object C (drilling surface). At this time, since the drilling surface and the contact surface S are in surface contact, the orthogonal state between the drilling surface and the drill bit 2 can be stably maintained. In this state, by performing a drilling operation with the electric drill 3, holes can be formed in a direction perpendicular to the drilling surface. Furthermore, since the contact sheet 54 (contact surface S) is made of an elastic material, the piercing object C is not damaged when the nose block 41 is abutted against the piercing object C. The contact sheet 54 preferably has an anti-slip function. Thereby, it is possible to effectively prevent the shaft bit of the drill bit 2 at the start of the drilling operation and the positional deviation during the drilling operation.

  Further, the planar dimension of the plate portion 52 is 90 mm × 40 mm corresponding to the dimension (94 mm × 54 mm) of the “new fore” frequently used as the exterior tile. Further, in FIG. 3, an aiming member 55 for indicating the axial center of the drill bit 2 is provided on the upper side of the abutting guide portion 43 and in the center in the width direction. With these configurations, accurate alignment can be performed with respect to the required drilling location of the drilling target C, and proper drilling can be performed at a desired position. In addition, the planar dimension of the plate part 52 is not limited to the above dimensions, and it is preferable to arbitrarily change the drilling object C or the like according to usage conditions.

  In FIG. 3, a discharge port 56 is formed through the lower side of the block portion 53 from the inner peripheral surface of the insertion opening 51 where the tip portion of the drill bit 2 faces obliquely rearward. One end of a connection member 57 (joint) is screwed and fixed to the discharge port 56, and the collection tube 7 c is connected to the other end of the connection member 57. Thereby, the coolant recovery means 7 is connected to the insertion opening 51 via the discharge port 56, the connection member 57 and the recovery tube 7 c, and the coolant supplied to the drill bit 2 is sucked by the coolant recovery means 7. It is collected (see FIG. 1).

  A pair of guide fixing | fixed part 44 is arrange | positioned in FIG. The front end portions of the first slide guide 34 and the second slide guide 35 are fixed to the respective guide fixing portions 44. Accordingly, the nose block 41 is supported by the slide guide 32 extending in parallel from the pair of guide holders 31.

  As shown in FIG. 5A, the dust seal 45 is formed of an elastic material such as rubber, and is in close contact with the cylindrical portion 45a inserted into the insertion opening 51 of the abutting guide portion 43 and the perforated object C. A horn portion 45b having a form of an inner and outer double annular seal piece and a seal flange portion 45c interposed between the cylindrical portion 45a and the horn portion 45b are integrally formed. The cylindrical portion 45a is formed in a bottomed cylindrical shape, and an insertion hole 45d communicating with the above-described insertion opening 51 is formed in the bottom portion (FIG. 5B). Further, an oval discharge hole 45e communicating with the discharge port 56 is formed on the inner peripheral surface of the cylindrical portion 45a.

  As shown in FIGS. 4 and 5 (b), the insertion opening 51 opened in the abutting guide portion 43 includes a small-diameter opening 51a opened substantially at the same diameter as the diameter of the cylindrical portion 45a in the rear, and a front portion. A large-diameter opening 51b that is opened with substantially the same diameter as the diameter when the horn portion 45b is pressed and expanded. The large-diameter opening 51b has such a depth that the seal flange portion 45c slightly enters the contact surface S when the dust seal 45 is inserted and attached to the insertion opening 51 from the front. That is, in a state where the dust seal 45 is attached to the insertion opening 51, the horn portion 45 b slightly protrudes from the contact surface S.

  In a state where the nose block 41 is at the most advanced position, the cutting blade 11 of the drill bit 2 is accommodated in the dust seal 45 with a predetermined gap. When the nose block 41 is pressed against the drilling object C along with the drilling operation, the cutting blade 11 cuts into the drilling object C while relatively projecting from the close dust seal 45. At this time, since the seal flange portion 45c is pressed against the edge of the small-diameter opening 51a, the dust seal 45 does not sink into the insertion opening 51 (small-diameter opening 51a).

  Further, as shown in FIG. 5 (b), as the dust seal 45 is pressed against the drilling target C, the inner and outer double annular seal pieces of the horn portion 45b bend and expand radially outward, and the drilling target Adhere to C. At this time, the bent horn portion 45b expands within the large-diameter opening 51b while retreating relatively, so that the horn portion 45b and the contact surface S are flush with each other. Thereby, the contact surface S (contact sheet 54) is also brought into close contact with the piercing object C together with the horn portion 45b. In this way, the perforation edge is double sealed by the dust seal 45 and the contact sheet 54 is in close contact with the dust seal 45 so that the perforated surface and the drill bit 2 are orthogonal to each other. Scattering and leakage of the coolant mixed with dust can be effectively prevented while stably maintaining.

  On the other hand, the dust-mixed coolant that has flowed out of the perforated hole is sucked and collected by the coolant collecting means 7 through the discharge hole 45e and the discharge port 56 of the dust seal 45. The recovered coolant is preferably filtered and reused.

  As shown in FIGS. 4 to 6, the bearing member 42 is a so-called sliding bearing, and is a male screw that engages with a female screw (not shown) formed on the rear inner peripheral surface of the small-diameter opening 51 a of the nose block 41. A bearing screw portion 61 formed with a screw 61a, a hexagonally processed bearing tightening portion 62 with which a tool (wrench) is engaged when screwed into the small-diameter opening 51a, a bearing screw portion 61 and a bearing tightening portion 62; And a bearing flange portion 63 interposed therebetween.

  A through hole 64 through which the shank 12 of the drill bit 2 can penetrate in the axial direction is formed at the center of the bearing member 42. The through-hole 64 has a diameter that is substantially the same as the diameter of the shank 12, and has a dimensional tolerance that allows the rotation of the drill bit 2 and the sliding of the shank 12 due to drilling. Note that the specific dimensional tolerance is preferably in the range of 0.01 to 1 mm.

  When the bearing member 42 is screwed into the small-diameter opening 51a from the rear, the bearing flange portion 63 comes into contact with the rear end face of the nose block 41, and the bearing member 42 is fixed to the small-diameter opening 51a (FIG. 5B). reference). In this state, the front end (front end) of the bearing screw portion 61 is in close contact with the base end (rear end) of the cylindrical portion 45 a of the dust seal 45 inserted and mounted in the insertion opening 51. Further, the through hole 64 of the bearing member 42 communicates with the insertion hole 45 d of the dust seal 45.

  As a result, the bearing member 42 can be securely fixed to the nose block 41 in a desired posture, the rotational runout of the drill bit 2 can be suppressed, and the rotational accuracy can be improved. In addition, the bearing member 42 can be easily replaced by simply unscrewing and fixing with a tool. Furthermore, since the bearing member 42 is provided in close contact with the dust seal 45, the rotational runout of the drill bit 2 in the dust seal 45 can be effectively suppressed.

  In addition, both openings of the through hole 64 are chamfered, and the bearing member 42 has a “mountain” cross section (see FIGS. 5B and 6B). Thereby, since the contact area of the inner surface of the through-hole 64 and the shank 12 becomes small, rotational resistance and sliding resistance are reduced. Further, the drill bit 2 that is the initial work can be smoothly attached. Furthermore, even if the runout or deflection occurs in the drill bit 2, it is possible to prevent the through-hole 64 and each opening thereof from being damaged due to the runaway of the drill bit 2. The drill bit 2 is attached to the output shaft 22 through the through hole 64 of the bearing member 42 fixed to the nose block 41 from the shank 12 side.

  The material constituting the bearing member 42 is preferably composed of ceramic, hard resin, or bearing alloy. In this embodiment, an acrylic resin is used as the hard resin. In addition, polyvinyl chloride, polypropylene, polyethylene, ABS resin, polycarbonate and the like can be considered. Moreover, as a bearing alloy, white metal, an aluminum alloy, a titanium alloy, stainless steel, etc. can be considered. By configuring the bearing member 42 with the material as described above, the rotational resistance and sliding resistance with the shank 12 can be reduced, and smooth rotation of the drill bit 2 can be realized. Moreover, durability can be provided against wear of the bearing member 42 due to contact with the shank 12, and the replacement frequency of the bearing member 42 can be reduced.

  According to the above configuration, the drill bit 2 is rotatably supported by the bearing member 42 provided in the nose block 41 in a state where the drill bit 2 is mounted on the electric drill 3 and at the distal end portion of the shank 12. Further, since the shank 12 of the drill bit 2 and the bearing member 42 are slidably engaged in the axial direction, the drilling is guided in a state in which the rotational runout is suppressed. As a result, the rotational runout on the tip side of the drill bit 2 can be effectively suppressed, so that accurate drilling can be performed at a desired position, and a good finish with no defects on the surface of concrete, tile, or the like. Holes can be formed.

(Second Embodiment)
The bearing member 42 according to the second embodiment will be described with reference to FIG. Only differences from the bearing member 42 according to the first embodiment will be described.
As shown in FIG. 7A, the bearing member 42 has a thin cylindrical appearance, and a through hole 64 is formed in the axial center thereof. Moreover, the internal thread part formed in the internal peripheral surface of the small diameter opening 51a of the nose block 41 is abbreviate | omitted, and the bearing member 42 fits into the internal peripheral surface of the small diameter opening 51a. With the bearing member 42 fitted, the distal end (front end) of the bearing member 42 is in close contact with the base end (rear end) of the cylindrical portion 45 a of the dust seal 45 inserted and mounted in the insertion opening 51. According to this configuration, as in the first embodiment, the bearing member 42 can be easily fixed to the nose block 41 in a desired posture, and the rotational deflection of the drill bit 2 can be suppressed. In addition, the bearing member 42 can be easily replaced.

(Modification of the second embodiment)
As shown in FIG. 7B, the bearing member 42 has an outer peripheral surface of the bearing member 42 according to the second embodiment covered with an elastic member 65 made of, for example, rubber or silicon resin. According to this configuration, since the elastic member 65 is in close contact with the inner peripheral surface of the small-diameter opening 51a of the nose block 41, the bearing member 42 is fixed in a desired posture within the small-diameter opening 51a. Note that the elastic member 65 may be disposed at equal intervals on the outer peripheral surface of the bearing member 42 instead of covering the bearing member 42 (see FIG. 7C).

(Third embodiment)
With reference to Fig.8 (a), the bearing member 42 which concerns on 3rd Embodiment is demonstrated. Only differences from the bearing member 42 according to the first embodiment and the second embodiment will be described. The bearing member 42 is in contact with the rear end surface of the cylindrical portion 45 a of the dust seal 45 and is covered with an elastic material constituting the dust seal 45. That is, the bearing member 42 according to the third embodiment is formed integrally with the dust seal 45. According to this configuration, replacement of the dust seal 45 and replacement of the bearing member 42 can be performed simultaneously.

(Fourth embodiment)
With reference to FIG.8 (b), the bearing member 42 which concerns on 4th Embodiment is demonstrated. Only differences from the bearing member 42 according to the first to third embodiments will be described. The bearing member 42 is formed integrally with the nose block 41. According to this configuration, the nose block 41 and the bearing member can be fixed in a desired positional relationship.

(Fifth embodiment)
With reference to FIG.8 (c), the bearing member 42 which concerns on 5th Embodiment is demonstrated. Only differences from the bearing member 42 according to the first to fourth embodiments will be described. The bearing member 42 according to the fifth embodiment is configured by a ball bearing instead of the plain bearing employed in the bearing member 42 according to the first to fourth embodiments. According to this configuration, smooth rotation of the drill bit 2 can be ensured.

  2: drill bit, 3: electric drill, 5: guide attachment, 11: cutting blade, 12: shank, 33: anti-vibration mechanism, 41: nose block, 42: bearing member, 43: abutting guide, 45: dust seal 51: insertion opening, 64: through hole, 65: elastic member

Claims (10)

An anti-vibration mechanism that suppresses vibration due to rotation of a drill bit composed of a cutting blade and a shank attached to an electric drill that is hand-held for drilling work,
Wherein mounted on the electric drill, it is fixed to the distal end of the guide attachments for guiding the drilling of the drill bit, and abutted nose block puncture hole object,
A bearing member that is provided in the nose block and supports the shank rotatably and slidably in the axial direction ;
The bearing member has a through-hole in which the drill bit penetrates in the axial direction and both openings are chamfered,
The nose block has a block body and a dust seal formed of an elastic material,
The dust seal includes a bottomed cylindrical cylindrical portion attached to the inner surface of the block main body, and a horn portion that is in close contact with the perforation edge of the perforation object,
An insertion hole through which the drill bit is inserted is formed at the bottom of the cylindrical portion,
The bearing mechanism is disposed so as to be in close contact with a bottom portion of the cylindrical portion . The anti-sway mechanism according to claim 1 , wherein the bearing member is screwed into an insertion opening formed in the nose block so that the drill bit can be inserted. The anti-sway mechanism according to claim 1 , wherein the bearing member is fitted and fixed to an insertion opening formed in the nose block so that the drill bit can be inserted. The anti-vibration mechanism according to claim 3 , wherein an elastic member is interposed on an outer peripheral surface of the bearing member. 2. The anti-sway mechanism according to claim 1 , wherein the bearing member faces an insertion opening formed in the nose block so that the drill bit can be inserted, and is integrally formed with the nose block. . The drill bit is a diamond core bit;
The anti-sway mechanism according to any one of claims 1 to 5 , wherein the dust seal is configured to be able to recover the coolant supplied via the drill bit. The anti-skid mechanism according to claim 6 , wherein the bearing member is formed integrally with the dust seal. The bearing member, stop mechanism vibration according to any one of claims 1 to 7, characterized in that it is constituted by a sliding bearing. The antiskid mechanism according to claim 8 , wherein the sliding bearing is made of any one of ceramics, hard resin, and a bearing alloy. The bearing member, stop mechanism vibration according to any one of claims 1 to 7, characterized in that it is constituted by a ball bearing.

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