JP2018062021A - Hole saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hole saw which further reduces falling of chips and cut pieces to the inner side of a punched member and the side opposite to the punched side.SOLUTION: A hole saw 1 forms a circular through hole in a member formed by a magnetic material and includes: a cylindrical body part 2 having multiple cutting blades 5 at a tip; cutout parts 3, each of which is formed at the body part 2 and connects the adjacent cutting blades 5; and a magnet part 4 which is provided at the inner side of the body part 2 so as to move in an axial direction of the body part 2 and may contact with the member. A size of the cutout part 3 when viewed along the axial direction of the body part 2 is larger than a thickness of the magnet part 4 when viewed along the axial direction of the body part 2.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a hole saw, and more particularly to a hole saw in which the fall of chips on the inside of a drilled member or on the side opposite to the drilled side is further reduced as compared with the related art.

  A chip recovery device is known in which a magnet is provided in an end mill in which a hole saw is formed at the tip in order to reliably take out a section to the outside of the pipe when the fluid pipe is drilled (see Patent Document 1).

JP 2003-251510 A

  However, the amount of chips recovered was small even though the section after perforation could be retained. Therefore, the improvement of the collection | recovery efficiency of the section | slice and chip after drilling was calculated | required.

  In view of this, the problem to be solved by the present invention is to provide a hole saw in which the falling of chips and pieces on the inner side of the perforated member or on the side opposite to the perforated side is further reduced as compared with the prior art. .

  As means for solving the above-mentioned problems, a hole saw according to the present invention is a hole saw in which a circular through hole is formed in a member made of a magnetic material, and a cylindrical main body portion having a plurality of cutting edges at a tip thereof. A cutout portion formed on the main body portion for connecting adjacent cutting blades, and a magnet portion provided inside the main body portion so as to be movable in the axial direction of the main body portion and capable of contacting the member. The size of the body portion along the axial direction of the body portion is larger than the thickness of the magnet portion along the axial direction of the body portion.

  In the hole saw according to the present invention, it is preferable that a gap is formed around the magnet portion in a state where the magnet portion is disposed in the main body portion.

  In the hole saw according to the present invention, it is preferable that the magnet portion is detachably attached to the main body portion.

  In the hole saw according to the present invention, it is preferable that the magnet portion includes an urging portion and a collecting portion having magnetic force, and the urging portion urges the collecting portion toward a member with which the collecting portion abuts.

  In the present invention, by forming the notch part and the magnet part to a specific size, during drilling, the chips enter the main body part through the notch part and adhere well to the magnet part. A section cut out from the perforated site is also attached to the magnet portion. For this reason, according to the present invention, it is possible to provide a hole saw in which the fall of chips on the inner side of the perforated member or on the side opposite to the perforated side is further reduced as compared with the prior art, as well as prevention of dropping of the slice.

  Further, according to the present invention, it is preferable that a gap is formed around the magnet portion in the main body portion, so that a region where a large amount of chips can adhere to the magnet portion can be secured.

  Furthermore, according to the present invention, by making the magnet part detachable from the main body part, preparation before drilling, chips after drilling, taking out of the section and magnet part from the main body part, maintenance management of the magnet part, etc. Is preferable, and working efficiency is improved.

  Further, according to the present invention, the urging portion of the magnet portion urges the collecting portion toward the member that is the object to be drilled, so that the collecting portion having a magnetic force always maintains contact with the member. This is preferable.

FIG. 1 is a schematic perspective view showing an example of a tool including a hole saw according to the present invention. FIG. 2 is a schematic cross-sectional view showing a drilled portion in the tool of FIG. FIG. 3 is an enlarged schematic view showing a part of the drive unit in the perforated part of FIG. FIG. 4 is a schematic diagram illustrating a part of the driving unit of FIG. 3 in an exploded manner. FIG. 5 is a schematic view showing the drive unit before drilling. FIG. 6 is a schematic view showing a drive unit during drilling. FIG. 7 is a schematic view showing the drive unit after drilling. FIG. 8 is an exploded schematic view of a part of the drive unit after drilling.

An embodiment of a hole saw according to the present invention will be described with reference to FIGS.
FIG. 1 is a schematic perspective view showing an example of a tool 100 provided with a hole saw according to the present invention. FIG. 2 is a schematic cross-sectional view showing a drilled portion 101 in the tool 100 of FIG. FIG. 3 is an enlarged schematic view showing a part of the drive unit 102 in the punching unit 101 of FIG. FIG. 4 is a schematic view showing a part of the drive unit 102 of FIG. 3 in an exploded manner.

As shown in FIG. 1, the tool 100 includes a perforated part 101 and a gripping part 103. The tool 100 is an electric tool for performing a drilling operation for forming a through hole in the side surface of the pipe P. The pipe P is an object to be drilled by the tool 100, and is an example of the “member” in the present invention. The pipe P is a cylindrical body containing a magnetic material, for example, iron, cobalt, nickel, and the like, and various fluids such as city gas and water can be circulated therein.
In addition, the drilling target object of the tool provided with the hole saw according to the present invention is not limited to the illustrated cylindrical pipe P, and may be a plate body or the like.

  The perforating part 101 is a part for perforating the pipe P. The perforated part 101 will be described later with reference to FIGS. The grip 103 is a part that holds the pipe P and the punch 101 so that the relative position between the pipe P and the punch 101 does not move so that the drilling position does not shift. In the present embodiment, the grip portion 103 has a contact portion 104 that contacts the outer surface of the pipe P within a predetermined range, and the two contact portions 104 sandwich the peripheral surface of the pipe P from one side and the other side. Both abutting portions 104 are fixed by bolting.

  Subsequently, as illustrated in FIG. 2, the perforation unit 101 includes a drive unit 102 and a body unit 105. The drive unit 102 will be described later with reference to FIGS. 3 and 4. The body part 105 is a part fixedly attached to the grip part 103, and supports the shaft of the drive part 102 that is rotationally driven so as not to be shaken.

  As shown in FIG. 3, the drive unit 102 includes a drive shaft 106 and a hole saw 1. The drive shaft 106 is a shaft that rotates when a driving force from an appropriate power source is transmitted to one end as rotation, and a hole saw 1 described later is attached to the other end.

  The hole saw 1 includes a main body 2, a notch 3, and a magnet 4.

  The main body 2 is a cylindrical body having a plurality of cutting blades 5 at the tip. The cutting blade 5 is a portion formed by polishing the end of the cylindrical body constituting the main body 2 and is formed so as to be able to cut the drilling object by sliding with respect to the drilling object. The cutting blades 5 are arranged in a circle along the peripheral surface of the main body 2. The main body part 2 is in contact with the drilling object at one end part shown on the lower side in the drawing, which is the tip side. In addition, the main body 2 is fixedly attached to the other end of the drive shaft 106 at the other end shown on the upper side in the drawing, which is the side opposite to the tip. Thus, the rotation received by the drive shaft 106 is transmitted to the main body 2 so that the main body 2 can also rotate.

  The notch 3 is formed in the main body 2 and connects adjacent cutting blades 5 to each other. Specifically, the cutout portion 3 is a cutout portion formed on the peripheral surface of the main body portion 2, extends from one cutting blade 5 to the other end portion side of the main body portion 2, and extends to another adjacent cutting blade 5. It is formed linearly and curvedly. Note that “X” shown in FIG. 3 is along the axis of the main body 2 from the tip of the main body 2 where the notch 3 is formed to the end of the notch 3 on the other end side of the main body 2. The size of the notch 3 (hereinafter, simply referred to as “size of the notch 3”).

  The magnet unit 4 is inserted into the drive shaft 106 and the main body unit 2 as shown in FIG. As a specific structure of the magnet part 4, a recovery part 41, a shaft part 42 and a sleeve 43 are provided as shown in FIG. 4 in a state of being pulled out from the drive shaft 106 and the main body part 2.

The collection unit 41 is formed in a disk shape using a permanent magnet such as a neodymium magnet, and can attract a drilling object including a magnetic material. Note that “Y” shown in FIG. 3 is the thickness of the collection unit 41 along the axis of the main body 2 in the magnet unit 4 (hereinafter, sometimes simply referred to as “the thickness of the magnet unit 4”).
In the present invention, the recovery unit may be an electromagnet that draws an object to be drilled by conducting only during drilling, instead of the permanent magnet.

  The shaft portion 42 is a shaft body fixedly attached to one end surface of the collection portion 41. Further, the sleeve 43 is a cylindrical body, and a part of the shaft portion 42 is inserted therein and is held by the other end portion of the drive shaft 106.

  A coil spring 44 is wound around the shaft portion 42 along the shaft portion 42. With the coil spring 44, the recovery part 41 and the shaft part 42 can maintain the initial positions shown in FIG. The coil spring 44 is an example of an urging portion in the present invention. As the urging portion, instead of the coil spring 44, an air spring, a bamboo shoot spring, a leaf spring, an elastomer, or the like can be used.

  In addition, on the peripheral side surface of the portion inserted into the sleeve 43 of the shaft portion 42, a slide hole 45, which is an elliptical long hole, is formed so that the long axis of the ellipse coincides with the axis of the shaft portion 42.

  Further, when the locking pin 46 fixed to the sleeve 43 is inserted into the slide hole 45, when the shaft portion 42 is inserted into and removed from the sleeve 43, the movable range of the shaft portion 42 is the locking pin 46. Is limited to a range in which the slide hole 45 moves from one end to the other end. That is, the movable range of the shaft portion 42 is restricted by the slide hole 45 and the locking pin 46.

  When the shaft portion 42 is further inserted into the sleeve 43 than the state shown in FIGS. 2 and 3, the coil spring 44 is shortened between the shaft portion 42 and the sleeve 43, and an urging force acts. The shaft portion 42 and the sleeve 43 are about to be restored to the initial state shown in FIGS.

  As shown in FIG. 4, the magnet unit 4 is provided so as to be insertable / removable with respect to the drive shaft 106 and the main body unit 2 and is detachable. Specifically, an engagement groove 47 that is a recess is formed on the circumferential surface of the sleeve 43 over one circumference. As shown in FIGS. 2 and 4, the drive shaft 106 is fixedly provided with an engaging portion 6 that is a convex portion that can be engaged with the engaging groove 47 of the sleeve 43.

  By engaging the engaging portion 6 and the engaging groove 47, the magnet portion 4 can be held in the drive shaft 106. The depth of the engaging groove 47 is formed so that the engagement state with the engaging portion 6 can be easily released by manually pulling out the collecting portion 41 from the main body 2. Has been.

  Since the engaging groove 47 is formed over the entire circumference of the peripheral surface of the sleeve 43, even if the drive shaft 106 rotates while the engaging portion 6 and the engaging groove 47 are engaged, the engaging groove 47 is engaged. The joining portion 6 slides on the peripheral surface of the sleeve 43 along the engaging groove 47. Thereby, a rotational force is not transmitted to the magnet part 4 or is difficult to be performed. Therefore, it is possible to stably hold the pipe P, the section, and the like with which the magnet unit 4 comes into contact.

  With the above configuration, the magnet unit 4 is provided with the collection unit 41 and the shaft unit 42 movably in the axial direction of the main body unit 2 inside the main body unit 2, and the collection unit 41 is disposed on the pipe P that is a drilling target. Contact is possible.

As shown in FIG. 3, the size X of the notch 3 is formed larger than the thickness Y of the magnet 4. In other words, the recovery part 41 of the magnet part 4 is exposed from the peripheral side surface of the main body part 2 through the notch part 3. Further, as shown in FIG. 2 and FIG. 4, the collection unit 41 in the magnet unit 4 is arranged in the main body unit 2 in the vicinity thereof, that is, between the collection unit 41 and the inner surface of the main unit 2 and the cutting blade 5. A gap is formed between the connecting portion of the shaft portion 42 of the collecting portion 41 and the like.
The effect | action by these structures is later mentioned, referring FIGS. 5-8 with description about a perforation process.

Here, the usage pattern of the hole saw 1 according to the present embodiment will be described with reference to FIGS. 5 to 8, only a part of the drive unit 102 in the tool 100 is shown in an enlarged manner in order to show the drilling form of the hole saw 1.
FIG. 5 is a schematic view showing the drive unit 102 before drilling. FIG. 6 is a schematic diagram showing the drive unit 102 during drilling. FIG. 7 is a schematic view showing the drive unit 102 after drilling. FIG. 8 is an exploded schematic view of a part of the drive unit 102 after drilling.

  First, the drive part 102 is arrange | positioned in the state which the collection | recovery part 41 of the magnet part 4 contact | abutted with respect to the outer surface of the piping P which is a piercing | punching object. At this time, as shown in FIG. 5, a part of the cutting blade 5 is also in contact with the outer surface of the pipe P. In this state, the collection unit 41 continues to maintain the contact state by attracting the pipe P containing the magnetic material.

  Although not shown in FIG. 5, in this state, the gripping portion 103 shown in FIG. 1 fixes the relative position between the drilling portion 101 having the driving portion 102 and the pipe P. However, after the perforation part 101 is positioned at the perforation position of the pipe P and the perforation part 101 is fixed by the grip part 103, the recovery part 41 may be brought into contact with the pipe P.

  Next, while driving the drive unit 102 against the pipe P, an appropriate power source is operated to rotate the drive unit 102. Thereby, as shown in FIG. 6, the cutting blade 5 sliding on the outer surface of the pipe P drills while cutting the pipe P. At this time, since the collection unit 41 remains in contact with the outer surface of the pipe P, only the cutting edge 5 is gradually buried in the pipe P. As the cutting blade 5 is buried in the pipe P, the recovery part 41 is relatively pushed into the other end side of the main body part 2 together with the shaft part 42 by the outer surface of the pipe P. Further, when the collection part 41 and the shaft part 42 are pushed into the main body part 2, a biasing force of the coil spring 44 is generated in a direction in which the collection part 41 and the shaft part 42 are pushed back. Thereby, the collection | recovery part 41 can maintain the state contact | abutted with respect to the piping P during a drilling and after a drilling.

  When the cutting blade 5 cuts the pipe P, fine chips G are generated. As described above, since the size X of the cutout portion 3 is formed larger than the thickness Y of the recovery portion 41 of the magnet portion 4, as shown by the black arrow in FIG. It enters the main body 2 through the notch 3. The chips G that have entered the main body 2 adhere to the recovery unit 41 by magnetic force. As described above, since the collection unit 41 can always maintain the contact state with the pipe P by the biasing force of the coil spring 44, the collection unit 41 is not detached from the pipe P during drilling. Thereby, the collection | recovery of the chip G by the collection | recovery part 41 can always be performed during perforation.

  If the drilling of the pipe P is further continued, all the cutting blades 5 penetrate the pipe P and the drilling is completed. After the drilling, when the drive unit 102 is pulled out from the pipe P, the section F remains in the main body 2 as shown in FIG. From the time of drilling to the removal work after drilling, the collection unit 41 is kept in contact with the section F, and the section F and the chips G are held by the magnetic force of the collection unit 41.

  Next, FIG. 8 shows the magnet part 4 in a state where the hole saw 1 that has been perforated is removed from the pipe P and further pulled out from the main body part 2. If the magnet part 4 is pulled out from the main body part 2 after drilling, the removal work of the slice F and the chips G becomes easy.

  As shown in FIGS. 7 and 8, a through hole O is formed in the pipe P by drilling the hole saw 1. The part that was present in the through hole O as a part of the pipe P is cut out by the hole saw 1 and attached to the recovery part 41 of the magnet part 4 as a slice F and a chip G. When the cutting blade 5 penetrates the pipe P, the collection unit 41 can maintain the attached state of the section F by the magnetic force, so that the section F can be prevented from falling into the pipe P.

  In the existing hole saw, only the section F is collected if the hole saw uses a magnet. However, in this case, the collection of the chips G is not performed or the collected amount remains small, and a large amount of the chips G is dropped inside the pipe P after drilling. Similarly, when the object to be punched is a plate-like object, the chips G were dropped to the side opposite to the punching side. Therefore, conventionally, after the drilling operation of the pipe P, it is necessary to clean the pipe P.

  On the other hand, in the hole saw 1 according to the present embodiment, not only the section F generated from the pipe P during and after drilling but also the chip G drops into the pipe P by the notch portion 3 and the magnet portion 4. Therefore, it is further suppressed or reduced as compared with the conventional case.

  The chips G generated during drilling may accumulate on the drilling side of the pipe P and outside the main body 2, that is, on the upper outer surface of the pipe P shown in FIGS. 5 to 8. Since at least a part of such chips G is attracted to the collection part 41 and enters the main body part 2 through the notch part 3 and adheres to the collection part 41, the collection efficiency of the chips G is good.

  Further, as described above, the rotation of the magnet portion 4 is not transmitted by the engagement groove 47 even when the drive shaft 106 and the main body portion 2 are driven to rotate, so that the chips G are scattered by rotation or the like especially during and after drilling. This is preferable.

  Furthermore, when pulling out the magnet part 4 after drilling as shown in FIG. 8, the recovery part 41 can be easily pulled out by inserting a screwdriver or the like from the notch part 3 into the main body part 2 and pushing it out toward the cutting blade 5. . Thereby, the removal operation | work of the slice F and the chip G from the magnet part 4 becomes easy.

  As described above, since the gap is formed between the collection unit 41 in the magnet unit 4 and the inner surface of the main body unit 2 and the drive shaft 106, the main body unit 2 and the drive shaft 106 itself are made of the slice F and the chips G. Adhesion to the collection part 41 is not inhibited. Thereby, especially the recovery amount of the chip G can be improved.

  In addition to the embodiments illustrated above, various forms can be adopted as long as the object of the present invention can be achieved.

  In the present invention, the shape of the notch is not particularly limited, and may be determined in view of, for example, strength required for the cutting blade. Moreover, in the said embodiment, the notch part 3 is uniformly formed so that the shape and magnitude | size X may become the same in all the notch parts 3. FIG. On the other hand, in the present invention, it is not essential that the cutout portion has a uniform shape and a size along the axis of the main body portion. For example, the cutout portion is appropriately set in view of cutting performance and strength required for a hole saw. It is good. In addition, when the shape and size of the notch portion varies from one notch portion to another, the size of the notch portion that is formed most along the axis of the main body portion can be adopted as “X”.

In addition to the magnetic force of the magnet part, when more securely holding the section from which the object to be drilled is cut out, the center drill may be protruded from the substantially central part of the magnet part and the main body part. In this case, the center drill is preferably arranged so that the rotation from the drive source is transmitted only to the center drill while protruding from the substantially central portion of the magnet portion.
With this arrangement, before the drilling, the center drill is first rotationally driven to be inserted into the drilling object, and the magnet part is brought into contact with the drilling object, so that the section is cut by the insertion by the center drill and the magnetic force of the magnet part. Holds firmly. In addition, since the center axis of the drilling site is fixed by the center drill, the drilling position is less likely to be displaced and blurred during drilling.

  It is preferable to attach a suction means in the main body in the present invention. The suction unit is a unit that sucks air inside the main body to make the inside of the main body at least a negative pressure from the atmospheric pressure. More specifically, as the suction means, for example, a communication hole communicating with the outside can be provided in the main body, and a fan that can blow air from the inside to the outside of the main body can be employed in the vicinity of the communication hole. By providing suction means, the chips generated in the main body due to drilling can be retained in the main body, reducing the discharge of chips from the notch to the outside of the main body, and reducing the amount of chips in the magnet section. The recovery amount can be further improved.

  In the present invention, the size of the notch is preferably such that the surface opposite to the drilling side of the magnet portion is exposed through the notch until the drilling operation is completed. In other words, it is preferable that the cutout portion is greatly cut out to the other end portion side than the magnet portion in a state immediately before the completion of drilling in which the magnet portion is most pushed into the main body portion. By providing the cutout portion of this size, the chips can enter the main body portion through the cutout portion until the completion of drilling, so that it is possible to ensure better recovery efficiency of the chips.

  As mentioned above, although embodiment which applied the invention made | formed by this inventor was described, this invention is not limited by the description and drawing which make a part of indication of this invention by this embodiment. That is, it should be added that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

1: Hole saw 2: Body part 3: Notch part 4: Magnet part 41: Collection part 42: Shaft part 43: Sleeve 44: Coil spring 45: Slide hole 46: Locking pin 47: Engaging groove 5: Cutting blade 6: Engagement part 100: Tool 101: Perforation part 102: Drive part 103: Gripping part 104: Abutting part 105: Body part 106: Drive shaft P: Piping O: Through hole G: Chip F: Section X: Notch part Size Y: Magnet thickness

Claims (4)

A hole saw that forms a circular through hole in a member made of a magnetic material,
A cylindrical main body having a plurality of cutting edges at the tip;
A notch formed in the main body and connecting adjacent cutting blades;
A magnet part provided inside the main body part so as to be movable in the axial direction of the main body part and capable of contacting the member;
The size of the cutout portion along the axial direction of the main body portion is larger than the thickness of the magnet portion along the axial direction of the main body portion.
Hole saw. A gap is formed around the magnet part in a state of being arranged in the main body part.
The hole saw according to claim 1. The magnet part is detachably attached to the main body part.
The hole saw according to claim 1 or 2. The magnet part has an urging part and a recovery part having magnetic force,
The biasing portion biases the recovery portion toward the member with which the recovery portion abuts.
The hole saw in any one of Claims 1-3.

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