JP4067084B2 - Core drill one-touch mounting structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to attachment / detachment of a core drill to / from a shank, and more particularly, to one-touch attachment / detachment of a core drill to / from a shank.
[0002]
[Prior art]
Core drills are used to make holes in concrete buildings and structures. The core drill is a drilling tool that scrapes off the vicinity of the outer diameter of a hole to be drilled, stores the core in the core drill, leaving the core at the center of the hole, and discharges it collectively.
The core drill is connected to a rotational drive source via a shank. The connection between the core drill and the shank is preferably attached with one touch.
A conventional one-touch attachment structure is shown in FIG. 5 as described in, for example, JP-A-9-11007.
[0003]
In Fig. 5, provided on the inner peripheral surface of the shank (not shown), toward the shank core drill 62 the ball is pressed and held by a spring to be movable in the radial direction of the shank along a first insertion groove 61 A part of the partial spherical hole provided in the second insertion groove 63 is constituted by being advanced and rotated along the endless second insertion groove 63 orthogonal to the first insertion groove 61. The ball is engaged with the engaging portion 64 to be attached.
Since the ball is held by a locking / holding mechanism used in one-touch connection parts such as gas or water, the core drill and shank can be used unless the release member (the member that allows the ball to retract) is operated. Is not cut off.
Reference numeral 68 denotes a chip discharge groove.
[0004]
In the case shown in FIG. 5, the core cut out by the blade body 65 is temporarily stored in the core storage portion 66, but the core is inclined or laterally displaced and is taken out by the blade body 65. There are problems such as difficulty.
Since the hole diameter of the through hole 67 of the core drill 62 is reduced as shown in the drawing, the core cannot be taken out through the through hole 67 even if the core drill 62 is removed from the shank.
[0005]
Another one-touch type attachment mechanism is shown in FIG .
In Fig 6, the engagement pin 72 which projects to the outer peripheral surface of the shank 71, is formed in the axial direction on the inner peripheral surface of the shank attachment portion 75 provided at the rear end of the core drill 74 with bit 73 at the distal end The first insertion groove 76 is advanced along the first insertion groove 76 against the elastic force of the compression spring 79, and the second insertion is formed in the circumferential direction orthogonal to the end of the first insertion groove 76. The shank 71 and the core drill 74 are attached by advancing and rotating along the groove 77. The compression spring 79 is located between the rotary connecting portion 80 and the engagement ring 81, and the engagement ring 81 and the shank attachment portion 75 are in surface contact.
[0006]
When the shank 71 and the core drill 74 are separated from each other, the engagement pin 72 is moved and rotated along the second insertion groove 77 to align the engagement pin 72 with the position of the first insertion groove 76. Can be advanced along the first insertion groove 76. When the power transmission pin 78 provided in the second insertion groove 77 is engaged with the engagement pin 72, the rotational driving force is transmitted. Reference numeral 83 denotes an O-ring that stops cutting water or the like flowing from the water passage hole 82 and is fitted into the O-ring groove 84.
[0007]
In the conventional one-touch attachment mechanism shown in FIG. 6, when it is difficult to remove the core housed in the core drill 74 from the blade body side, the shank 71 and the core drill 74 are separated from each other, so that the core can be easily removed from the opposite side. It can be taken out. However, with respect to the play between the engagement pin 72 and the second insertion groove 77, the core drill 74 is normally pushed away from the shank 71 by the compression spring 79, and the engagement pin 72 is in the second insertion groove 77. Is pressed against the wall on the drive coupling side. When the drilling operation is started, the core drill is pushed against the drilled body and pressed toward the shank 71, so that the engagement pin 72 is pressed against the wall of the second insertion groove 77 on the core drill 74 side. Become. As a result, within the range of play between the engagement pin 72 and the width of the second insertion groove 77, there is a difficulty in causing blurring.
[0008]
If the direction of relative rotation is wrong at the time of attachment, the engagement pin 72 and the power transmission pin 78 need to move beyond the first insertion groove 76 in order to engage, and the core drill 74 and the shank 71 are attached to each other. There is also the difficulty that there is a risk of undressing.
Further, the engagement between the shank 71 and the core drill 74 is basically made by one-surface contact between the outer peripheral surface of the shank 71 and the inner peripheral surface of the shank attachment portion 75 of the core drill 74. Few. Since the engagement ring 81 with which the rear end surface of the shank attachment portion 75 is engaged is engaged with the compression spring 79 at the other end of the engagement ring 81, the anti-blur effect is not exhibited.
[0009]
[Problems to be solved by the invention]
In view of the above-described problems, an object of the present invention is to provide a one-touch attachable / detachable core drill attachment structure that can transmit a sufficiently large rotational force and has very little blurring.
[0010]
[Means for Solving the Problems]
Core drill attachment structure of this onset Akira one-touch detachable is,
A core drill 31 having a bit 33 at the front end and a shank attaching portion 34 at the rear end, and a shank 32 connected to a rotational drive source;
The shank attachment part 34 is basically a hollow body, and has a central recess 36 for receiving the shank engagement part 42 on the inner side. The shank attachment part 34 extends in the axial direction on the outer side surface along the circumferential direction at the innermost part. It has an engaging projection receiving groove 37 that bends, and a rotation transmission pin receiving recess 38 at the front end of the shank,
The shank 32 includes a shank body 39, a shank cover body 40, and a spring 41 that repels the shank body 39 and the shank cover body 40 in a direction to separate them.
The shank main body 39 is integrally formed with a shank engaging portion 42 at the front, a flange portion 43 at the central portion, and a shank large-diameter portion 44 at the rear. The outer peripheral surface of the flange portion 43 is formed on the core drill 31. It matches the outer diameter of the shank attachment part 34 of
A rotation transmission pin 45 is provided on the outer peripheral surface of the shank engaging portion 42 in the vicinity of the flange portion 43,
An engagement protrusion receiving recess 46 for an engagement protrusion 47 for fixing the shank cover body 40 is formed on the outer periphery of the flange portion 43.
A connecting portion 48 with a rotational drive source is formed on the shaft portion of the shank large diameter portion 44.
The shank cover body 40 has a central hole 49 having an inner diameter corresponding to the outer diameters of the shank attachment portion 34 of the core drill 31 and the flange portion 43 of the shank body 39, and the shank large diameter portion 44 at the rear end. An inner flange portion 50 corresponding to the outer diameter of the inner flange portion 50 is formed, and an engagement protrusion 47 is attached to the tip side toward the inner side.
The spring 41 is arranged between the flange portion 43 of the shank main body 39 and the inner flange portion 50 of the shank cover body 40.
The engaging projection receiving recess 46 formed in the flange portion 43 has a wall surface a on the rotational drive source side and a shape in which the core drill side is notched, and the engaging projection 47 is formed on the shank cover body 40. The engagement protrusion 47 is detachably attached to the distal end side, and the engagement protrusion 47 is prevented from being detached by fitting the C ring 52 into a C ring receiving groove 53 provided along the outer periphery of the shank cover body 40. In addition, it is preferable that an O-ring groove 55 for the sealing O-ring 54 is formed in the circumferential direction on the outer peripheral portion of the shank engaging portion 42.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The core drill one-touch mounting structure of the present invention has a type in which the engagement between the shank and the core drill is made up of a retractable drop ball stored on the shank side and a drop ball receiving groove provided on the core drill side, The type is roughly divided into a type formed by an engaging protrusion on the shank side and an engaging protrusion receiving groove provided on the core drill side.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1, for explaining the core drill one-touch attachment structure according to the present invention, is an exploded explanatory view of the core drill and the shank. Figure 2 is a schematic cross-sectional view of D-D line in FIG. 1, FIG. 3 is a schematic cross-sectional view as seen from E-E arrow line in FIG. 4 is a schematic cross-sectional view of line F-F of FIG.
[0012]
Core drill one-touch mounting structure of the present onset bright, as shown in FIG. 1, consisting of a core drill 31 and the shank 32..
The core drill 31 includes a cylindrical portion 35 provided with a bit 33 at the front end and a shank attachment portion 34 at the rear end. The diameter and length of the cylindrical part 35 can be made arbitrary according to the thickness and depth of the hole drilled in concrete or the like.
The bit 33 may be formed by laminating a cemented carbide layer around the entire circumference of the tip of the cylindrical portion 35, if necessary, by providing a partial cutout, or by providing a plurality of cemented carbide chips or the like by brazing or the like. It may be a thing.
The shank attaching portion 34 is basically a hollow body, and has a central recess 36 that slidably receives a shank engaging portion 42 (to be described later) of the shank main body 39 on the inner side of the rear end.
[0013]
Further, an engagement protrusion receiving groove 37 that extends in the axial direction and bends along the circumferential direction is formed on the outer peripheral surface of the cylindrical shank attachment portion 34, and on the shank side of the shank attachment portion 34. At a certain rear end, a U-shaped rotation transmission pin receiving recess 38 is formed.
The angle at which the engagement protrusion receiving groove 37 bends in the circumferential direction at the innermost portion may be inclined at an appropriate angle in the direction perpendicular to the axial direction or in the direction of the rotational drive source or the core drill. However, from the standpoint of preventing disconnection, as shown in the figure, it is desirable to form it so as to bend toward the rotational drive source side.
[0014]
The shank 32 includes a shank body 39, a shank cover body 40, and a spring 41 (compression spring) that repels the shank body 39 and the shank cover body 40 in a direction to separate them.
The shank main body 39 is basically a hollow body, and has a shank engaging portion 42 inserted and engaged with the central recess 36 of the shank attachment portion 34 of the core drill 31 at the front, a flange 43 at the center, and a shank at the rear. The large-diameter portion 44 is formed integrally.
The outer diameter of the shank engagement portion 42 corresponds to the inner diameter of the central recess 36 of the shank attachment portion 34 of the core drill 31, and the outer diameter of the flange portion 43 is equal to the outer diameter of the shank attachment portion 34 of the core drill 31. Match.
[0015]
The shank engaging portion 42 is provided with a rotation transmission pin 45 standing in the vicinity of the flange portion 43 on the outer peripheral surface thereof, and an engaging protrusion 47 for fastening the shank cover body 40 is engaged with the outer periphery of the flange portion 43. A mating engagement receiving recess 46 is formed.
The engaging projection receiving recess 46 has a wall surface a on the rotational drive source side, and is formed in a cutout shape so that the core drill 31 side can enter and exit the engaging projection 47.
The rotation transmission pin 45 is erected by means such as screwing in a mounting hole formed on the outer peripheral surface of the shank engagement portion 42, and receives the rotation transmission pin received at the tip of the shank attachment portion 34 of the core drill 31. It engages with the recess 38. The rotation transmitting pin 45 may be erected on the outer peripheral surface of the shank engaging portion 42 by welding or integral molding.
[0016]
The engagement projection receiving recess 46 formed in the flange portion 43 of the shank body 39 is adapted to engage the distal end portion of the engagement projection 47 attached to the distal end side of the shank cover body 40 described later.
A screw hole is formed in the shaft portion of the shank large-diameter portion 44 to be a connection portion 48 with the rotation drive source. For example, the screw hole is formed in a size corresponding to a male screw formed on a drive shaft of a drill serving as a rotational drive source. The connection part 48 does not necessarily have a screw hole, and may be any other appropriate connection type as long as it can be firmly connected to the rotational drive source.
[0017]
The shank cover body 40 is basically cylindrical, and the inner diameter of the central hole 49 that forms the inside corresponds to the outer diameter of the shank attachment portion 34 of the core drill 31 and the outer diameter of the flange portion 43 of the shank body 39. The outer peripheral surface of the shank attachment portion 34 of the core drill 31 and the outer peripheral surface of the flange portion 43 of the shank main body 39 can slide on the inner peripheral surface of the central hole 49 of the shank cover body 40.
The rear end of the shank cover body 40 is integrally formed with a ring-shaped inner flange portion 50 extending toward the axial center. The inner diameter of the inner flange portion 50 corresponds to the outer diameter of the shank large-diameter portion 44. The front end portion of the inner flange portion 50 can slide on the peripheral surface of the shank large-diameter portion 44.
[0018]
Further, an engagement protrusion 47 is attached to the front end side of the shank cover body 40 inward in the circumferential direction. The engaging protrusion 47 can be detachably engaged with and attached to a through hole 51 provided on the distal end side of the shank cover body 40 by means of screwing or the like. The engaging protrusion 47 is attached to the shank cover. By engaging with the through-hole 51 from the outside of the body 40 and projecting inward, the tip portion can be engaged with the engaging projection receiving recess 46 of the flange portion 43.
The attachment portion for the engagement protrusion 47 of the shank cover body 40 is thickened and formed into a flange shape, and a through hole 51 is provided on the peripheral surface thereof to connect the engagement protrusion 47 and the shank cover body 40. It is recommended to strengthen the strength.
Further, a C-ring receiving groove 53 that passes over the through hole 51 along the outer periphery of the shank cover body 40 is provided, and the head of the engaging protrusion 47 that is screwed into the through hole 51 by fitting the C ring 52 into this groove. It is preferable that the portion can be slidably pressed to prevent the engagement protrusion 47 from coming off from the through hole 51.
[0019]
The spring 41 is disposed between the flange portion 43 and the inner flange portion 50 of the shank cover body 40 on the shank large-diameter portion 44, and the spring 41 is contracted by moving the shank cover body 40 to the core drill side. The shank cover body 40 is attached to the shank body 39 by engaging the engaging protrusion 47 attached to the tip of the shank cover body 40 with the engaging protrusion receiving recess 46 of the flange portion 43, thereby forming the shank 32. It is like that.
[0020]
In the shank 32, the shank cover body 40 is constantly pressed from the shank body 39 to the rotational drive source side by the spring 41 with the engaging protrusion 47 locked to the wall surface a of the engaging protrusion receiving recess 46. However, when the rotation transmission pin 45 is engaged with the rotation transmission pin receiving recess 38 of the core drill 31 and the shank cover body 40 is moved toward the core drill 31 against the elastic force of the spring 41, the engagement protrusion 47 is engaged. It is separated from the wall surface a of the mating projection receiving recess 46 and its notch, and is introduced into the engaging projection receiving groove 37 of the shank attaching portion 34 of the core drill 31.
In addition, although the spring 41 in the illustrated example has a circular cross section, an appropriate one such as a rectangular cross section may be employed.
[0021]
Next, an operation procedure when the shank 32 having the above configuration is connected to the core drill 31 will be described.
First, the shank cover body 40 is grasped, and the rotation transmission pins 45 erected on the outer peripheral surface of the shank engagement portion 42 are inserted and engaged with the rotation transmission pin receiving recesses 38 of the core drill 31, respectively.
Next, when the shank cover body 40 is further moved to the core drill 31 side in the inserted and engaged state, only the shank cover body 40 moves to the core drill 31 side against the elastic force of the spring 41, and together with it. The engaging protrusion 47 protruding inward of the shank cover body 40 moves away from the engaging protrusion receiving recess 46 of the flange portion 43 and is introduced into the engaging protrusion receiving groove 37 of the core drill 31, and in the axial direction of this groove. It hits the deepest part that stretches.
When the shank cover body 40 is rotated in the circumferential direction in the butted state, the engaging protrusion 47 moves along the groove that is bent along the circumferential direction formed in the engaging protrusion receiving groove 37, and the innermost part of the groove At this point, the connection work is easily completed.
To release the connection, the shank cover body 40 can be easily released by simply rotating the shank cover body 40 in the opposite circumferential direction and pulling the shank 32 away from the core drill 31.
[0022]
In this embodiment of the core drill one-touch attachment structure of the present invention, the core drill 31 and the shank 32 are connected by the inner peripheral surface of the central recess 36 of the core drill 31, the outer peripheral surface of the shank engaging portion 42, and the shank removal of the core drill 31. The front end surface of the shank side of the attaching portion 34 and the side surface of the flange portion 43 of the shank main body 39, the outer peripheral surface of the shank attaching portion 34 of the core drill 31, and the outer peripheral surface of the flange portion 43 of the shank main body 39 of the shank 32 and the shank cover body 40. Since it is engaged and connected at three locations (three surfaces) with the inner peripheral surface of the central hole 49, the rattling seen in the conventional core drill 74 and shank 71 connection structure shown in FIG. Is not generated at all, and there is no blurring during drilling.
[0023]
In this embodiment, the engagement projection receiving groove 37 and the rotation transmission pin receiving recess 38 formed on the outer periphery of the shank attachment portion of the core drill 31, and the rotation formed on the engagement projection 47 and the shank 32 that engage with these, respectively. Although three transmission pins 45 formed at equal intervals in the circumferential direction are shown, the number of transmission pins 45 is not limited to this and is set to an appropriate number according to the sizes and functions of the core drill 31 and the shank 32.
The core drill 31 is usually drilled by flowing cutting water or cooling water through a water passage hole formed in the shaft center. In this case, an O-ring groove 55 in which an O-ring 54 for sealing is formed in the circumferential direction of the shank engaging portion 42 in order to prevent cutting water or the like from leaking between the shank attaching portion 34 and the shank main body 39. Fit into and use.
[0024]
In addition, it is preferable to provide a knurled portion (not shown) in at least a part of the outer peripheral surface of the shank cover body 40, particularly in a flange-shaped portion, when applying a force for movement or the like to the shank cover body 40. .
Furthermore, if the outer peripheral surface of the shank cover body 40 is marked with a mark indicating the position of the engaging protrusion 47 or a rotational direction, for example, a groove groove mark, the core drill 31 and the shank 32 can be Useful when removing.
[0025]
【The invention's effect】
According to the present invention, the core drill and the shank can be attached and separated with one touch by moving the shank cover body against the spring force of the spring.
The core drill is always pulled toward the shank by the spring force of the spring, so that when the drilling starts, the shank and core drill are engaged by the ball and the ball receiving groove. In such a case, the engagement between the retaining ball and the retaining ball receiving groove is not disengaged, and in the case of the type formed by the engaging protrusion and the engaging protrusion receiving groove, the connection between the core drill and the shank is loosened. In any case, there is no fear of blurring at the start of drilling.
Further, in the case of the type in which the core drill and the shank are connected by the retaining ball and the retaining ball receiving groove, the surface contact engagement structure has two locations (two surfaces). In the case of the type formed with the receiving groove, since it is a surface contact engagement structure at three locations (three surfaces), there is no backlash and there is no blurring during drilling. Therefore, accurate drilling can be performed as compared with the prior art.
Furthermore, since the rotational force is transmitted by the engagement between the rotational transmission pin and the rotational transmission pin receiving recess, a sufficiently large rotational force can be transmitted. Since the shank cover body is provided, it also has a function of covering the main part of the attachment structure including the spring and protecting it from dust and the like.
[0026]
[Brief description of the drawings]
FIG. 1 is an exploded view of a core drill and a shank for explaining a core drill one-touch mounting structure according to the present invention.
2 is a schematic cross-sectional view of D-D line of FIG.
Figure 3 is a schematic cross-sectional view as seen from E-E arrow line in FIG.
4 is a schematic cross-sectional view taken along line FF in FIG . 1. FIG.
FIG. 5 is an explanatory view showing an example of a conventional technique for attaching a core drill and a shank by one-touch.
FIGS. 6A and 6B are explanatory views showing another example of the prior art in which the core drill and the shank are attached by one-touch, where FIG. 6A is an exploded explanatory view, and FIG. 6B is a side view of the core drill as viewed from the right in FIG. It is.
[Explanation of symbols]
31: Core drill 32: Shank 33: Bit 34: Shank attachment part 35: Cylindrical part 36: Central recessed part 37: Engagement protrusion receiving groove 38: Rotation transmission pin receiving recessed part 39: Shank main body 40: Shank cover body 41: Spring 42: Shank engagement part 43: Flange part 44: Shank large diameter part 45: Rotation transmission pin 46: Engagement protrusion receiving recess 47: Engagement protrusion 48: Connection part (screw hole)
49: Center hole 50 (of shank cover body): Inner flange portion 51: Through hole 52: C ring 53: C ring receiving groove 54: O ring 55: O ring groove 61: First insertion groove 62: Core drill 63: Second insertion groove 64: Locking portion 65: Blade body 66: Core storage portion 67: Through hole 68: Chip discharge groove 71: Shank 72: Engaging pin 73: Bit 74: Core drill 75: Shank attachment portion 76 : First insertion groove 77: second insertion groove 78: power transmission pin 79: compression spring 80: rotary connection part 81: engagement ring 82: water passage hole 83: O ring 84: O ring groove a: Wall surface on the rotational drive source side of the joint receiving recess

Claims (5)

A core drill 31 having a bit 33 at the front end and a shank attaching portion 34 at the rear end, and a shank 32 connected to a rotational drive source;
The shank attachment part 34 is basically a hollow body, and has a central recess 36 for receiving the shank engagement part 42 on the inner side. The shank attachment part 34 extends in the axial direction on the outer side surface along the circumferential direction at the innermost part. It has an engaging projection receiving groove 37 that bends, and a rotation transmission pin receiving recess 38 at the front end of the shank,
The shank 32 includes a shank body 39, a shank cover body 40, and a spring 41 that repels the shank body 39 and the shank cover body 40 in a direction to separate them.
The shank main body 39 is integrally formed with a shank engaging portion 42 at the front, a flange portion 43 at the central portion, and a shank large-diameter portion 44 at the rear. The outer peripheral surface of the flange portion 43 is formed on the core drill 31. It matches the outer diameter of the shank attachment part 34 of
A rotation transmission pin 45 is provided on the outer peripheral surface of the shank engaging portion 42 in the vicinity of the flange portion 43,
An engagement protrusion receiving recess 46 for an engagement protrusion 47 for fixing the shank cover body 40 is formed on the outer periphery of the flange portion 43.
A connecting portion 48 with a rotational drive source is formed on the shaft portion of the shank large diameter portion 44.
The shank cover body 40 has a central hole 49 having an inner diameter corresponding to the outer diameters of the shank attachment portion 34 of the core drill 31 and the flange portion 43 of the shank body 39, and the shank large diameter portion 44 at the rear end. An inner flange portion 50 corresponding to the outer diameter of the inner flange portion 50 is formed, and an engagement protrusion 47 is attached to the tip side toward the inner side.
The core drill one-touch attachment structure, wherein the spring 41 is disposed between the flange portion 43 of the shank main body 39 and the inner flange portion 50 of the shank cover body 40. The engaging projection receiving recess 46 has a wall surface a to a rotary drive source side, core drill side notched shape core drill one-touch attachment structure according to claim 1 Symbol placement is formed in the flange portion 43. The engaging projection 47, the distal end side of the shank cover 40, removably core drill one-touch attachment structure according to claim 1 Symbol placement are attached. The engaging projection 47 is stopped has been has claim 1 Symbol placement of the core drill one-touch attachment structure omission by fitting the C-ring 52 to C-ring receiving groove 53 provided along the outer periphery of the shank cover 40. Wherein the outer periphery of the shank engaging portion 42, circumferential O-ring groove 55 core drill one-touch attachment structure according to claim 1 Symbol mounting is formed with the O-ring 54 for sealing.

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