JP3629016B2 - Core drill - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a core drill for perforating an object to be drilled with a center drill preceded by a center hole, and thereafter drilling a large-diameter hole concentric with the center hole by a core body. The present invention relates to a core drill that can easily remove a cut-out waste material remaining in a core body after drilling.
[0002]
[Prior art]
Conventionally, in order to smoothly drill a large-diameter hole, a core drill combining a center drill and a cylindrical core body provided with a drilling blade on the periphery of the opening has been widely used.
[0003]
In this type of drilling with a core drill, the center hole is drilled with a center drill before the object to be drilled, and then the core body drilling blade is cut to drill a large-diameter hole. At the time of completion, the cut waste material remains in the core body in the form of a center drill sticking into the center hole. This cut-out waste material has a center hole substantially equal to the center drill diameter, and the outer diameter of the cut-out waste material is substantially equal to the inner diameter of the core body. Therefore, the cut-out waste material does not easily come out due to being caught in the core body. This may hinder the progress of the drilling operation.
[0004]
Therefore, in order to make it easy to take out the cut-out waste material from the core body, the core body can be freely attached to and detached from the base body having the shank, and both can be separated after drilling and the cut-out waste material remaining in the core body can be easily taken out. A core drill of construction has been previously proposed by the applicant.
[0005]
For example, in the core drill disclosed in Japanese Patent No. 2520548, an engaging member that can be moved forward and backward in the radial direction is fitted in a core body attaching portion formed in a lower portion of a base body having a shank, and formed in an upper portion of the base body. An operation sleeve is mounted on the sleeve mounting portion so as to be movable up and down, and an operation piece formed at the lower portion of the operation sleeve is configured to be able to be pushed into the base of the engaging member, and the core body mounting portion is inserted and inserted. The opening of the core body is provided with an engagement hole for engaging and disengaging the tip of the engagement member.
[0006]
In the core drill having this configuration, the base and the core body are joined by pulling up the operating sleeve, the operating piece is separated from the base of the engaging member, the engaging member is moved backward by the spring force, and the tip of the engaging member is the core. Since the core attachment part is inserted into the opening of the core body in this state and the operation sleeve is released in this state, the operation piece is brought into contact with the base of the engagement member under the spring force that pushes down the operation sleeve. When pushed, the engaging member moves forward, and its tip is projected and engaged with the engaging hole of the core body to join the base body and the core body. Thus, it is used for perforation.
[0007]
Then, when removing the cut-out scrap remaining in the core body after finishing the drilling, if the operating sleeve is pulled up, the operating piece is separated from the base of the engaging member in the reverse order, and the engaging member is moved backward by the spring force. Then, the distal end of the engaging member is extracted from the engaging hole of the core body, the engagement is released, and the base body and the core body can be separated. Since there is no obstacle in the opening on the coupling side of the core body separated from the base in this way, the cut-out waste material can be easily taken out from this opening.
[0008]
Therefore, according to the core drill having the above-described configuration, the operation sleeve can be operated to easily connect and separate the base body and the core body in a one-touch manner, and the removal of the cut-out waste material from the core body can be easily and reliably performed. .
[0009]
[Problems to be solved by the invention]
However, in the core drill having the above-described configuration, a plurality of fitting holes are provided in the core body attaching portion in the radial direction, and an engaging member that moves forward and backward is fitted therein, and the tip thereof is attached to the core body attaching portion. The core body attaching portion is restricted in size (radius) when assembling the engaging member to the core body attaching portion since it is caused to appear in and out of the peripheral surface and engage and disengage with the engaging hole of the core body.
[0010]
Therefore, the core drill having the above-described configuration is applied to a core drill that is combined with a core body having a relatively large diameter, and is combined with a core body having a relatively small diameter that makes it difficult to assemble the engaging member in space with respect to the core body attaching portion. It is not suitable for core drills.
[0011]
Therefore, an object of the present invention is to provide a core drill that can easily take out the cut-out waste material remaining in the core body after drilling, regardless of the size of the core body.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a core drill according to the present invention is provided with a joint hole opened downward in a base body having a shank, and a center drill is attached to the center of the base body in the joint hole. On the other hand, in the core drill for detachably coupling the core body via the coupling holding means, the core body is attached to the intermediate body coupled to the coupling hole, and the wall surface of the center drill through hole provided in the intermediate body is provided. Providing a guide rod in the direction of the bus bar and providing a push rod separately provided on the outer peripheral surface with protrusions that fit in the guide groove. The push rod can be inserted into the center drill hole instead of the center drill. It is characterized by.
[0013]
Here, the intermediate body to which the core body is attached is formed with a large-diameter cylindrical coupling portion that fits and is coupled to the coupling hole in the upper half portion, and the center drill through hole is the center of the lower half portion. A male screw is provided on the outer peripheral surface of the lower half, and the male screw is screwed into a female screw hole provided at the center of the top plate of the core body to attach the core body.
[0014]
In addition, as a means for holding and joining the intermediate body with respect to the coupling hole, a coupling ball that is disposed on the peripheral wall of the coupling hole, protrudes and retracts into the coupling hole, and engages and disengages with a coupling recess provided on the outer circumferential surface of the joint body, and the coupling ball A core body attaching / detaching ring that is rotatably arranged on the peripheral wall of the coupling hole of the base body and regulates the protrusion and withdrawal of the coupling ball in the coupling hole, and a core body pushing spring disposed in the coupling hole, A support portion is provided which extends to the lower end of the spring and regulates the projection of the coupling ball into the coupling hole by sliding on the inner surface of the coupling hole.
[0015]
When the base body and the intermediate body (core body) are separated from each other, the coupling ball retracts from the coupling hole, the core body pushing spring extends, and the support portion faces the front surface of the coupling ball and enters the coupling hole. To prevent the protrusion of. At the time of coupling with the base body, when the coupling portion of the intermediate body is fitted into the coupling hole and the support portion is pushed up from the front surface of the coupling ball, the coupling ball is released from the bearing portion, and the coupling recess provided on the outer peripheral surface of the coupling portion of the relay body When the ball reaches the position of the coupling ball, the coupling ball protrudes into the coupling hole and engages with the coupling recess. Here, the coupling relationship is maintained in the coupling ball by rotating and pressing the core body attaching / detaching ring.
[0016]
In this way, the base body and the core body are joined via the intermediate body and provided for perforation.
[0017]
According to the core drill of the present invention configured as described above, in a state where the base body and the core body are coupled via the intermediate body, the center drill is inserted into the center drill through hole provided in the intermediate body, and the lower part of the core body. Protrusively. Therefore, the drilling of the object to be drilled is performed in the same manner as normal drilling, with the center drill preceding the center hole, and thereafter, the core body drilling blade is cut to drill the large-diameter hole. Here, since the center drill is inserted into a center drill through hole provided in the intermediate body and the center base of the center drill is supported, the center runout of the center drill is reduced and the drilling accuracy is increased.
[0018]
At the time of drilling, the core body has a cutout scrap that remains in the form of a center drill sticking into the center hole. Separate the core body from the
[0019]
At this time, the core body is separated from the base body in the reverse order of the coupling, and when the core body attaching / detaching ring is rotated to release the restraint of the joint ball, the joint ball is withdrawn from the joint hole and the joint body is joined. Since the engagement with the recess is released, the intermediate body can be easily removed from the coupling hole.
[0020]
In this way, the separately prepared extrusion rod is inserted into the center drill through hole of the intermediate body from which the center drill has been removed, and the cut waste material remaining in the core body is pushed out. At this time, the push rod is inserted by inserting the protrusion provided on the outer peripheral surface thereof into the guide groove provided on the wall surface of the center drill through-hole, and the center hole of the cut-out waste material in which the tip of the push rod remains in the core body It is pushed to the hole in the hole. When the push rod is pushed in while shaking the whole in this way, the catch of the cut waste material in the core body is eliminated, and the cut waste material is easily taken out.
[0021]
In the present invention, since the center drill and the push rod are inserted through the same center drill through hole, the push rod has the same diameter as the center drill, and the protrusion rod tip outer peripheral surface is formed with a protrusion-free strip portion. The protrusion-free strip of the extrusion rod can enter the hole of the central hole of the cut-out scrap, and the end of the projection can be locked to the edge of the hole. It can be operated to quickly remove the catch of the cut-out waste material, thereby making it easier to take out and improving workability.
[0022]
Further, in the present invention, there are no particular restrictions on the number of guide grooves provided on the wall surface of the center drill through-hole and the number of protrusions provided on the outer peripheral surface of the extrusion rod corresponding thereto. Since the end of the protrusion is locked to the hole edge of the center hole of the waste material, and the pushing force is transmitted to the cut waste material, the structure is provided with three protrusions equally distributed on the outer peripheral surface of the push rod Then, the pushing force from the push rod through each protrusion end can be transmitted evenly in a balanced manner to the hole edge of the central hole of the cut-out scrap material, and cut out from the core body. Make it easier to take out the waste.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0024]
1 is a front view showing a part of the core drill of the present invention in section, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is a section showing a part of the intermediate body to which the core body is attached. FIG. 4 is a cross-sectional view taken along line BB in FIG. 3, FIG. 5 is a plan view of the extruded rod, and FIG. 6 is a front view in which a portion of the extruded rod is cut away.
[0025]
In the figure, a base 1 is provided with a coupling hole 3 opened downward by a cylindrical coupling hole peripheral wall 2, and a shank 4 supported by a chuck (not shown) of a drive shaft is provided at the center of the top surface of the top plate. .
[0026]
Accommodating holes 5 are provided at three locations around the peripheral wall 2 of the coupling hole, and coupling balls 6 that appear and disappear in the coupling hole 3 are arranged in these accommodating holes 5. The size of the coupling ball 6 here, that is, the diameter of the coupling ball 6 is set slightly larger than the thickness of the circumferential wall 2 of the coupling hole, and the inside of the circumferential wall of the coupling hole can be moved in and out by moving inside the housing hole 5. I have to. Although not shown, the accommodation hole on the coupling hole 3 side has a narrowed structure so that the coupling ball 6 is not pulled out to the coupling hole 3 side.
[0027]
A core body attaching / detaching ring 7 is rotatably disposed around the outer peripheral wall of the connecting hole of the base 1 corresponding to the connecting ball 6. On the inner peripheral surface where the core body attaching / detaching ring 7 slides on the peripheral wall 2 of the coupling hole, a retracting recess 8 for allowing a part of the coupling ball 6 to enter and retract the coupling ball 6 from the coupling hole 3 is provided. An annular spring accommodating portion 9 is recessed in the upper portion of 7 in a cut shape leaving the outer peripheral wall portion. The core body attaching / detaching ring 7 is supported by a support step that is fitted into the peripheral wall 2 of the base 1 and protrudes from the lower part of the peripheral wall, and the annular spring 10 is accommodated in the annular spring accommodating portion 9. One end is fastened to the peripheral wall 2 of the coupling hole of the base body 1, the other end is fastened in the annular spring accommodating portion 9, and a spring holding ring 11 is disposed thereon, and this is provided on the surface of the peripheral wall 2 of the joint hole. The support groove 12 is fitted to prevent it from coming off.
[0028]
The annular spring 10 according to the embodiment exerts a spring force in a direction in which both ends thereof are separated to increase the spring diameter. Based on the spring force of the annular spring 10, the core body attaching / detaching ring 7 is coupled. A predetermined angle is rotated around the hole peripheral wall 2.
[0029]
A core body pushing spring 13 is arranged in the coupling hole 3, and an inner surface of the engagement hole is slid at the lower end thereof, and a support portion 14 is provided to restrict the projection of the coupling ball 6 into the coupling hole 3. doing. In the embodiment, a single helical spring is used as the core body pushing spring 13, and one upper end of the spring is fitted into an engaging groove provided around the inner back end of the coupling hole 3. This portion is formed in the support portion 14 by winding the winding portion in close contact.
[0030]
The support portion 14 faces the front surface of the coupling ball 6 with the core body pushing spring 13 extended, and restricts (blocks) the projection of the coupling ball 6 into the coupling hole 3.
[0031]
The core body 15 has a cylindrical shape and is provided with a plurality of perforated blades 15a made of cemented carbide at the opening edge of the lower end. The core body 15 is attached to the intermediate body 16 coupled to the coupling hole 3. doing. In the embodiment, a male screw 19 is provided on the outer peripheral surface of the lower half portion of the intermediate body 16, and this is screwed into a female screw hole 17 provided in the center of the top plate 18 at the top of the core body to firmly attach the core body 15. Further, a through hole 22 through which the center drill 21 is inserted is provided at the center of the lower half portion of the intermediate body 16, and a guide groove 23 is provided on the wall surface of the through hole 22 in the generatrix direction.
[0032]
Further, in the upper half portion of the intermediate body 16 projecting on the core body 15, a large-diameter cylindrical coupling portion 16 a to be fitted and coupled to the coupling hole 3 is formed, and on the outer peripheral surface of the coupling portion 16 a, A coupling recess 20 is provided in which the coupling ball 6 engages and disengages.
[0033]
The center drill 21 is inserted into a mounting hole 24 provided in the center of the lower surface of the base body 1 in the coupling hole 3 and fixed by screwing a fixing screw 25 from the side of the mounting hole 24. Yes.
[0034]
In the present invention, an extrusion rod 26 is prepared separately from the center drill 21. The push rod 26 is inserted into the center drill hole 22 of the intermediate body 16 in place of the center drill 21, has the same length and the same diameter as the center drill 21, and a center drill is formed on the outer surface of the push rod 26. Protruding strips 27 that fit into the guide grooves 23 of the through holes 22 are provided, and non-protruding strip portions 28 are formed on the outer peripheral surfaces of both ends of the push rod 26 with an appropriate length. In the embodiment, the guide grooves 23 on the wall surface of the through hole 22 and the protrusions 27 on the outer peripheral surface of the push rod 26 are provided in an evenly distributed manner, but even if the number is increased more than this, Good.
[0035]
In the above configuration, when the core drill is used, the core body 15 is coupled to the base body 1 via the intermediate body 16 as shown in FIG. That is, when the coupling portion 16 a of the intermediate body 16 is fitted into the coupling hole 3 and the support portion 14 is pushed up against the core body pushing spring 13, the coupling ball 6 protrudes into the coupling hole 3 and the coupling body 16 is coupled. Engaging with the recess 20, the core body attaching / detaching ring 7 rotates around the connecting hole peripheral wall 2 by the spring force of the annular spring 10 and presses the connecting ball 6. Therefore, unless the core body attaching / detaching ring 7 is artificially rotated against the spring force of the annular spring 10, the coupling relationship between the base body 1 and the intermediate body 16 is maintained.
[0036]
When drilling is performed in this state, the center drill 21 is inserted into the center drill through hole 22 provided in the intermediate joint 16, and the center drill 21 is supported at the middle portion together with the base portion. Is reduced.
[0037]
The cut-out waste material A remaining in the core body 15 at the time when the drilling is completed remains in a form in which the center drill 21 is inserted into the center hole B. When the core body 15 is separated from the material to be punched and the cut waste A is not easily pulled out by being caught in the core body 15, the core body 15 is separated from the base 1 and taken out.
[0038]
At this time, the core body 15 is separated from the base body 1 by rotating the core body attaching / detaching ring 7 so that the coupling ball 6 is retracted to the side of the retracting recess 8 to disengage the intermediate body 16 from the coupling recess 20. In this state, the coupling portion 16a of the intermediate body 16 is removed from the coupling hole 3.
[0039]
Thus, as shown in FIG. 7, after the center drill 21 is pulled out from the center hole B of the cutout waste material A remaining in the core body 15, the cutout waste material A remains in the core body 15 by being caught or the like. As shown in FIG. 8, a separately prepared push-out rod 26 is inserted into the center drill through hole 22 of the intermediate body 16, and the cut-out waste material A is pushed out and taken out.
[0040]
At this time, the protrusion rod 27 on the outer peripheral surface of the push rod 26 is fitted into the guide groove 23 on the wall surface of the through hole, and the non-protrusion strip portion 28 at the tip end of the push rod 26 is the hole of the center hole B of the cut-out waste material A. Then, the end portions of the protrusions 27 are locked to the edge of the hole and pressed. Thus, when the push-out rod 26 is pushed in while shaking the whole, the cut waste material A in the core body 15 is removed from the core body 15 as shown in FIG.
[0041]
【The invention's effect】
The present invention is carried out in the form as described above. According to the present invention, the core body is attached to the intermediate body in the core drill that can be easily coupled / separated between the base body and the core body with a simple operation. The core body is coupled to the base body via the intermediate body, and the cut-out waste material remaining in the core body is taken out by inserting and pushing out an extrusion rod into the core body from the center drill through hole of the intermediate body. Regardless of the size of the body, it is possible to easily and reliably remove the cut-out waste material from the core body and improve workability.
[Brief description of the drawings]
FIG. 1 is a front view showing, in section, a part of a core drill showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is a front view showing, in section, a part of the intermediate body to which the core body is attached.
4 is a cross-sectional view taken along line BB in FIG.
FIG. 5 is a plan view of an extrusion rod.
FIG. 6 is a front view in which a part of an extrusion rod is cut away.
FIG. 7 is an exploded front view showing a state in which the core body in which the cut-out waste material remains is separated from the base body.
FIG. 8 is a cross-sectional view of a core body-related portion for explaining a procedure for taking out the cutout waste material.
FIG. 9 is a cross-sectional view of a core body-related portion for explaining a procedure for taking out the cutout waste material.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base | substrate 2 Bonding hole surrounding wall 3 Bonding hole 4 Shank 5 Housing hole 6 Bonding ball 7 Core body attaching / detaching ring 8 Retraction recessed part 9 Annular spring accommodating part 10 Annular spring 11 Holding ring 12 Supporting groove 13 Outlet spring 14 Bearing 15 Blade 16 Joint body 16a Joint portion 17 of joint body Female thread hole 18 Core body top plate 19 Male thread 20 Joint recess 21 Center drill 22 Center drill hole 23 Guide groove 24 Mounting hole 25 Fixing screw 26 Push rod 27 Projection strip 28 Projection Strip A Cut-out waste B Center hole

Claims (4)

A core drill in which a joint hole released downward is provided in a base body having a shank, a center drill is attached to the center of the base body in the joint hole, and the core body is detachably coupled to the joint hole via a joint holding means. The core body is attached to a joint body coupled to the coupling hole, and a guide groove is provided in the direction of the generatrix on the wall surface of the center drill through hole provided in the joint body, and the projection is fitted into the guide groove A core drill characterized in that an extrusion rod provided with a strip on the outer peripheral surface is separately prepared, and the extrusion rod can be inserted into a center drill hole instead of the center drill. 2. The core drill according to claim 1, wherein the push rod has the same diameter as the center drill, and a protrusion-free strip is formed on the outer peripheral surface of the tip of the push rod. The core drill according to claim 1 or 2, wherein three protrusions are provided on the outer peripheral surface of the push rod in an equidistant manner. In the upper half of the intermediate body, a large-diameter cylindrical coupling portion that fits and is coupled to the coupling hole is formed, a center drill through hole is provided at the center of the lower half, and a male screw is provided on the outer surface of the lower half. 2. The core drill according to claim 1, wherein the male screw is screwed into a female screw hole provided at the center of the top plate of the core body, and the core body is attached.

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