JPH1110417A - Fitting structure of rotating tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the workability of a rotating tool, and also to perform work with high accuracy by preventing the vibration of a hole cutter. SOLUTION: While engaging projections 22 are provided to a shank 12 for fitting a hole cutter 14, grooves 24 for engaging the engaging projections 22 are provided to the hole cutter 14. By engaging the engaging projections 22 with the grooves 24, the hole cutter 14 is fitted to the shank 12. Further, pressure-receiving surfaces 25 for pressedly bringing the respective engaging projections 22 into contact are formed on the deepest inside surfaces of the respective grooves 24 at the time of cutting work respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary tool such as a hole cutter for punching a workpiece.
More specifically, it relates to the mounting structure.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, an L-shaped groove portion 62 is formed on the upper portion of a hole cutter 60, while an engaging projection 63 projects on an upper outer peripheral surface of a drill shank 61. Has been established. Then, the drill shank 61 is fitted into the hole cutter 60, and the engaging protrusion 63 is engaged with the predetermined play in the groove portion 62, so that the hole cutter 60 is mounted on the drill shank 61 or the like. You. When the drill shank 61 is rotated as a tool (not shown) is driven, the hole cutter 60 is rotated.
Is rotated to perform a cutting process on the work. At the time of this cutting, since the cutting resistance acts on the hole cutter 60, the engaging projection 63 of the drill shank 61 is pressed against the inner deep surface (pressure receiving surface) 62 a of the groove 62 of the hole cutter 60.

[0003]

However, in the conventional hole cutter mounting structure, the hole cutter 60 is not used.
Inner surface 62a of the groove 62 is orthogonal to the rotation direction of the drill shank 61 (the direction of arrow B shown in FIG. 5), so if there is play between the groove 62 and the engagement projection 63,
There is a possibility that the hole cutter 60 vibrates in the rotation axis direction. When such vibrations occur, workability is reduced and high-precision machining becomes impossible.

Accordingly, an object of the present invention is to improve the workability and prevent the hole cutter from vibrating, thereby achieving high-precision machining.

[0005]

According to the first aspect of the present invention, a shank for attaching a rotary tool is provided with an engaging portion, and the rotary tool is provided with an engaged portion to which the engaging portion is engaged. In the rotary tool mounting structure in which the rotating tool is mounted on the shank by engaging the engaging portion with the engaged portion, the engaged portion is engaged when the rotating tool rotates. The gist is that a pressure receiving surface to which the joint portion is pressed is provided, and the pressure receiving surface is set so as to obliquely intersect the rotation direction of the shank.

According to a second aspect of the present invention, there is provided a rotary tool mounting structure according to the first aspect, wherein the pressure receiving surface is linear. According to a third aspect of the present invention, in the mounting structure for a rotary tool according to the second aspect,
The gist of the present invention is that the pressure receiving surface forms an acute angle with respect to the rotation direction of the shank.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a hole cutter mounting structure will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, a drill shank 12 detachable from a driving shaft 11a of a tool 11
2a and an insertion portion 1 protruding from the tip of the body portion 12a
2b. The base end of the center drill 13 is inserted into the body portion 12a and the insertion portion 12b on the rotation axis of the drill shank 12, and is fixed by screws (not shown).

A hole cutter 14 as a rotary tool is mounted on the insertion portion 12b of the drill shank 12, and in the mounted state, the insertion portion 12b of the drill shank 12 is fitted into the upper reduced diameter portion 14a of the hole cutter 14. . At the lower end of the hole cutter 14, a plurality of cutting blades 15 made of a carbide tip are brazed and joined at predetermined intervals in the circumferential direction of the hole cutter 14. A flange 16 projects from the outer peripheral surface of the insertion portion 12b of the drill shank 12, and an O-ring 1 is provided between the flange 16 and the body 12a to be in contact with the inner peripheral surface of the hole cutter 14.
7 are engaged.

As shown in FIGS. 1 to 3, a receiving hole 18 is formed in the insertion portion 12b of the drill shank 12 and extends in a radial direction of the insertion portion 12b. And are housed. One end of the compression spring 19 is in contact with the outer peripheral surface of the center drill 13, and the other end of the compression spring 19 is in contact with the engaging ball 20. The engagement ball 20 is urged radially outward of the insertion portion 12b by the compression spring 19. Further, a part of the engaging ball 20 protrudes outward from the housing hole 18, and the opening diameter of the housing hole 18 is smaller than the diameter of the engaging ball 20. There is no escape from 18. Then, the hole cutter 14 is connected to the drill shank 12.
, The hole cutter 14 is engaged with the inner end of the through hole 21 formed in the upper reduced diameter portion 14 a of the hole cutter 14.

As shown in FIGS. 1 and 2, a pair of engaging projections 22 are provided on the outer peripheral surface of the insertion portion 12b as engagement portions extending in the radial direction of the drill shank 12. As shown in FIG. In addition, a pair of grooves 24 are formed in the upper diameter-reduced portion 14a of the hole cutter 14 as engaged portions having a substantially inverted T shape, and the width of each groove 24 is larger than the diameter of each of the engagement protrusions 22. Is also getting bigger. Each engagement projection 22 is engaged with each groove 24 with play.

As shown in FIG. 4, pressure receiving surfaces 25 to which the respective engaging projections 22 are pressed when the hole cutter 14 rotates, that is, when the hole cutter 14 is cut, are formed on the inner deep surface of each groove 24, respectively. Each pressure receiving surface 25 has a linear shape and obliquely crosses downward with respect to the rotation direction of the drill shank 12 (the direction of arrow A shown in FIG. 4). Further, each pressure receiving surface 25 is set at an angle θ (45 degrees in the present embodiment) which forms an acute angle with respect to the rotation direction of the drill shank 12.

Next, the operation of the rotary tool configured as described above will be described. The insertion portion 12b of the drill shank 12 is fitted into the upper reduced-diameter portion 14a of the hole cutter 14 along the rotation axis direction of the drill shank 12, and the engaging projections 22 are engaged with the respective groove portions 24, and the hole cutter 14 Is rotated along its circumferential direction. Due to this rotation, each engagement protrusion 22 is moved to the mounting position P indicated by a solid line in FIG.
1 and the hole cutter 14 is
2 attached.

The upper diameter reducing portion 14 of the hole cutter 14
When the insertion portion 12b of the drill shank 12 is fitted into the hole a, the engagement ball 20 is immersed in the receiving hole 18 against the urging force of the compression spring 19. When each of the engaging projections 22 is locked at the mounting position P1 and the entire engaging ball 20 is positioned corresponding to the through hole 21 of the hole cutter 14, a part of the engaging ball 20 is compressed. The outer end opening 18a is projected from the inside of the accommodation hole 18 by the urging force of the spring 19, and
Is engaged. This engagement allows the rotating hole cutter 1 before cutting a work (not shown).
4 rattling is prevented.

Then, the rotation of the drive shaft 11a of the tool 11 rotates the drill shank 12 and the hole cutter 14, thereby cutting a work (not shown). During this cutting process, a cutting resistance force acts on the hole cutter 14, so that each engagement protrusion 22 is attached to the mounting position P1 indicated by a solid line in FIG.
To the operating position P2 indicated by the chain line in FIG. That is,
Each engagement projection 22 moves obliquely downward from the upper portion thereof while being pressed against the pressure receiving surface 25. By this movement, each engaging projection 22 does not rattle in the vertical direction, and the hole cutter 1
4 becomes stable. The engaging ball 20
Is moved to the operating position P2, the engaging ball 20 is not disengaged from the through hole 21 of the drill shank 12.

Next, effects that can be found from the present embodiment will be described below. A pressure receiving surface 25 for pressing the engaging projection 22 against each groove 24;
And the pressure receiving surface 25 is set so as to obliquely intersect the rotation direction of the drill shank 12. for that reason,
Due to the cutting resistance force acting on the hole cutter 14, the engagement protrusion 22 is pressed against the pressure receiving surface 25 so as to bite, so that the hole cutter 14 does not rattle in the vertical direction. Therefore, during the cutting, the rotation of the hole cutter 14 can be stabilized, the workability can be improved, and the machining can be performed with high precision.

Since the pressure-receiving surface 25 is linear, the pressure-receiving surface 25 can be easily cut by an end mill or the like, as compared with a case where the pressure-receiving surface 25 is formed into an arc or the like, for example.

Since the pressure receiving surface 25 is formed at an acute angle with respect to the rotation direction of the drill shank 12, each cutting protrusion 22 is moved along the pressure receiving surface 25 from the mounting position P1 to the operating position P2 during cutting. It can be moved smoothly and quickly. Therefore, during cutting, the rotation of the hole cutter 14 can be instantaneously stabilized.

The above embodiment may be configured as follows. -The pressure receiving surface 25 is not a straight line but an arc or the like, or is changed to any other shape.

The number of the engagement protrusions 22 and the groove portions 24 can be changed to any number as long as they are one or more. -In the said embodiment, the hole cutter 1 is used as a rotary tool.
Although 4 was used, any tool other than the hole cutter 14 may be used as long as it is a rotating tool.

Next, technical ideas other than the claims that can be grasped from the embodiment will be described together with their effects. (1) The mounting structure for a rotary tool according to claim 3, wherein the angle θ of the pressure receiving surface with respect to the rotation direction of the shank is in a range of 30 to 80 degrees.

(2) The mounting structure of a rotary tool according to claim 3, wherein the angle θ of the pressure receiving surface with respect to the rotation direction of the shank is in a range of 35 to 55 degrees. (3) The angle θ of the pressure receiving surface with respect to the rotation direction of the shank is 4
The mounting structure for a rotary tool according to claim 3, wherein the angle is 5 degrees. According to this configuration, the pressure contact force of the engagement portion with the pressure receiving surface can be set to the most appropriate value, and the rotary tool can be easily removed from the shank without applying force after the working operation.

[0023]

The present invention is configured as described above, and has the following effects. According to the first aspect of the present invention, since the engaging portion can be pressed against the pressure receiving surface of the engaged portion so as to bite, the rotating tool does not vibrate in the direction of the rotation axis thereof. Therefore, workability can be improved and processing can be performed with high accuracy.

According to the second aspect of the invention, the processing of the pressure receiving surface can be easily performed. According to the third aspect of the invention, the rotation of the rotary tool can be instantaneously stabilized during machining.

[Brief description of the drawings]

FIG. 1 is a front view showing a mounting structure of a hole cutter according to an embodiment.

FIG. 2 is a side sectional view showing a mounting structure of a hole cutter.

FIG. 3 is a sectional view taken along line XX of FIG. 1;

FIG. 4 is an enlarged front view of a hole cutter showing a main part.

FIG. 5 is a front view showing a mounting structure of a hole cutter showing a conventional technique.

[Explanation of symbols]

12: drill shank, 14: hole cutter (rotary tool), 22: engaging projection, (engaging portion), 24: groove (engaged portion), 25: pressure receiving surface

Claims (3)

[Claims] An engaging portion is provided on a shank for attaching a rotary tool, and an engaged portion is provided on the rotary tool to be engaged with the engaging portion. The engaging portion is engaged with the engaged portion. In the mounting structure of the rotary tool, wherein the rotary tool is mounted on the shank by being combined, the engaged portion is provided with a pressure receiving surface against which the engaging portion is pressed when the rotary tool rotates. A rotating tool mounting structure whose surface is set to cross diagonally to the rotation direction of the shank. 2. The mounting structure for a rotary tool according to claim 1, wherein said pressure receiving surface is formed in a straight line. 3. The mounting structure for a rotary tool according to claim 2, wherein said pressure receiving surface forms an acute angle with respect to a rotation direction of said shank.