JPH08294809A - Square hole working tool - Google Patents

Abstract

PURPOSE: To provide a square hole working tool by which prepared holes of a work can be worked into square holes by using a general purpose maching tool such as a drilling machine. CONSTITUTION: A holder 2 is provided with a holding object shaft part 8 held so as to be freely mountable and demountable in a concentric condition with a rotary main spindle by a tool holding tool freely movable so as to relatively approach and separate in its axial direction to the rotary main spindle 7 or a work holding rotary main spindle freely movable so as to relatively approach and separate in the axial direction to a fixed work W, and an edge body support shaft body 3 is autorotatably supported with the holder 2 around the axis 3a inclining to the axis 8a of the holding object shaft part 8 of the holder 2. A square hole working edge body 4 is provided with a square columned edge part 17 projecting from the edge body support shaft body 3, and the square columned edge part 17 becomes thick as it proceeds to the tip side, and the center 18a of its tip surface 18 is positioned at an intersection P between the axis 8a of the holding object shaft part of the holder 2 and the axis 3a of the edge body support shaft body 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a square hole machining tool for machining a cylindrical pilot hole previously provided in a work into various square holes such as a wrench hole using a drilling machine or a lathe. It is a thing.

[0002]

2. Description of the Related Art As a method of processing a square hole such as a wrench hole in various works, a method of forging a cylindrical prepared hole previously provided in the work into a square hole with a punch or the like,
There is a known method of cutting a through hole into a square hole with a slotter for slotting or a brooch, but in both cases, a dedicated machine tool is required for automatic processing, and there is no particular penetration. When machining the bottom square hole, the conventional forging method is
It could not be used as a small lot product processing method.

In view of the above conventional problems, the present invention utilizes a general-purpose machine tool such as a drilling machine or a lathe to easily and accurately machine a square hole having a bottom. It is an object of the present invention to provide a square hole machining tool that is suitable for machining small lots of products.

[0004]

A tool for machining a square hole according to the present invention for achieving the above object is a holder 2 and a blade body supporting shaft body, which are denoted by reference numerals of embodiments described later. Three
And a square hole machining blade body 4, and the holder 2 is rotatable relative to the fixed work W in the axial direction and is movable in the axial direction. The tool holder that can be moved toward and away from each other is provided with a held shaft portion 8 that is detachably held in a concentric state with the rotating main shaft, and the blade body supporting shaft body 3 is held by the holder 2. The square hole machining blade body 4 is rotatably supported by the holder 2 around an axis center 3a inclined with respect to the axis center 8a of the shaft portion 8 and projects from the blade body supporting shaft body 3. Part 1
7, the prismatic blade portion 17 becomes thicker toward the tip end side, and the center 18a of the tip end surface 18 thereof has the axis 8a of the held shaft portion of the holder 2 and the blade body supporting shaft body 3. Axis 3
It is located at the intersection P with a.

Although the square hole machining blade 4 can be formed integrally with the tip of the blade support shaft 3, it is attached to the tip of the blade support shaft 3. A base portion 16 detachably attached to the portion 13 and a prismatic blade portion 17 protruding from the blade body supporting shaft body 3 are provided so that the blade body supporting shaft body 3 can be replaced. Is desirable.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. In FIGS. 1A and 1B, reference numeral 1 is a square hole machining tool according to the present invention, which is a holder 2, a blade supporting shaft. It is composed of a body 3 and a square hole machining blade body 4.
As shown in FIG. 1C, the holder 2 is attached to, for example, a rotary spindle of a drilling machine, that is, a rotary spindle 7 that is movable toward and away from the workpiece W fixed on a table 6 by a workpiece clamp 5 in the axial direction. A tapered held shaft portion 8 which is detachably held in a concentric state with the rotating main shaft 7.
And a bearing portion 9 connected to the held shaft portion 8. The blade support shaft 3 has an axis 3a inclined by, for example, about 2 degrees with respect to the axis 8a of the held shaft 8 of the holder 2.
Is rotatably supported on the bearing portion 9 of the holder 2 via an angular ball bearing 10, a thrust ball bearing 11, and a shell type needle bearing 12, and a blade attachment portion 13 is attached to a tip protruding from the holder 2. Is equipped with. 14
Is an oil seal.

The square hole machining blade body 4 is detachably fitted to the blade body mounting portion 13 of the blade body supporting shaft body 3 and is fixed by a lock screw 15. And a prismatic blade portion 17 projecting from the shaft body 3, the prismatic blade portion 17 becoming thicker toward the tip end side and being flat at a right angle to the axis 3a of the blade body supporting shaft body 3. The center 18a of the tip end surface 18 is configured to be located at the intersection point P between the axis 8a of the held shaft portion 8 of the holder 2 and the axis 3a of the blade support shaft 3. The illustrated square hole machining blade 4 is for hexagonal hole machining as a wrench hole. Therefore, the prismatic blade portion 17 is a regular hexagonal prism, and the shaft center 3a of the blade body supporting shaft body 3 is provided. The angle of inclination of the side surface with respect to is equal to or slightly larger than the angle of inclination of the axis 3a of the blade supporting shaft 3 with respect to the axis 8a of the held shaft 8 of the holder 2 (2 degrees in this embodiment).

Square hole machining tool 1 constructed as described above
For example, as shown in FIG. 1C, the held shaft portion 8 of the holder 2 is concentrically attached to the rotary spindle 7 of the drilling machine, and the workpiece W fixed on the table 6 by the workpiece clamp 5 is processed into a square hole. A prepared hole H for this is provided. This pilot hole H
2A, as shown in FIG. 2A, is a cylindrical hole having substantially the same diameter as the circle inscribed in the hexagon of the tip surface 18 of the prismatic blade portion 17 in the rectangular hole machining blade 4, and if necessary, the The edge of the opening is chamfered. The chamfered portion Ha has such a size that the peripheral edge of the hexagonal tip surface 18 of the prismatic blade portion 17 can abut the slope of the chamfered portion Ha.

The prepared hole H is located concentrically with the main spindle 7 of the drilling machine, in other words, concentrically with the axis 8a of the held shaft portion 8 of the holder 2 of the square hole machining tool 1. As described above, when the work W is fixed on the table 6 by the work clamp 5, the rotary spindle 7 is lowered to form the prismatic blade portion 1 in the square hole machining blade 4 of the square hole machining tool 1.
The tip of 7 is pressed against the surface of the work W. To be precise, the square hole cutting blade 4 is integrally formed with the blade supporting shaft 3 in the holder 2
Since it is inclined with respect to the axis 8a of the held shaft portion 8 in the above, as shown in FIG. 2A, one portion of the hexagonal peripheral edge (corner portion in the tip surface 18 of the prismatic blade portion 17 is )
Will be pressed into contact with the slope of the chamfered portion Ha of the prepared hole H.

If the prismatic blade portion 17 and the workpiece W are brought into pressure contact with each other at the required pressure in the axial direction of the rotary spindle 7 (held shaft portion 8 of the holder 2) as described above, the rotary spindle 7 is driven. The square hole machining tool 1 is rotated around the axis 8a of the held shaft portion 8 of the holder 2. At this time, if the work W does not exist and the prismatic blade portion 17 is in an unloaded state, the blade body supporting shaft body 3 and the square hole machining blade body 4 are integrated with the holder 2 so that the shaft center 8a of the shaft center 8a is formed. Although it only rotates around, one place (corner) of the hexagonal peripheral edge on the tip surface 18 of the prismatic blade portion 17 is in pressure contact with the sloped surface of the chamfered portion Ha of the prepared hole H as described above. Since the rotation of the prismatic blade portion 17 is blocked, the square hole machining blade body 4 and the blade body supporting shaft body 3 are formed.
On the other hand, only the holder 2 rotates around the axis 8a. As a result, the square hole machining blade 4 and the blade support shaft 3 do not rotate, but the axis 8a of the holder 2 does not rotate. It will only revolve around.

That is, the prismatic blade portion 17 has a tip end surface 18 thereof.
In the state where the center 18a of the shaft is located at the intersection P between the shaft center 8a of the held shaft portion 8 of the holder 2 and the shaft center 3a of the blade body supporting shaft body 3, the shaft center 3a of the blade body supporting shaft body 3 is It does not rotate about its own axis, but makes a rotary swing motion around the axis 8a of the held shaft portion of the holder 2 with the intersection point P as the swing center.
Therefore, the pressure contact position between the work W and the peripheral edge of the prismatic blade tip end surface 18 inclined with respect to the axis 8a rolls in the circumferential direction without any relative sliding contact movement in the circumferential direction. Become. Therefore, in such a situation, if the rotary spindle 7 is forcibly fed in the direction (arrow F) in which the prismatic blade portion 17 is press-fitted into the prepared hole H of the workpiece W, the hexagonal periphery of the tip surface 18 of the prismatic blade portion Of these, the peripheral portion, which is the most advanced position with respect to the feed direction F, advances spirally in the depth direction of the prepared hole H.

The above operation will be described in more detail with reference to FIGS. 3 and 4. For example, the feed amount S per 180 degree rotation of the rotary spindle 7 (holder 2 of the tool 1 for square hole machining) is 0.3 m.
When m is set, the peripheral edge portion N, which is the most advanced position in the feed direction F of the rotary spindle 7 among the hexagonal peripheral edges of the tip surface 18 of the prismatic blade portion 17, is on a plane perpendicular to the axis 8a. With respect to a certain moving locus L1 when there is no forced feed, as shown by L2, the feed direction F is 0.1 mm after 60 ° rotation, 0.2 mm after 120 ° rotation, and 0.3 mm after 180 ° rotation. Proceed to step 0.6 mm after one revolution and 1. mm after two revolutions.
It is in a state of advancing in the feeding direction by 2 mm.

That is, among the hexagonal edges of the tip end surface 18 of the prismatic blade, the edge N, which is the most advanced position in the feed direction F, spirals in the depth direction of the prepared hole H at a pitch of 0.1 mm per 60 degrees. Similarly, the work W advances in a rolling state without any relative sliding movement. The peripheral portion N that rolls in a spiral shape shears and cuts the overlapping portion A of the work W and the peripheral portion N around the prepared hole H in the feed direction F. Note that the radial width D of the overlapping portion A is such that the peripheral edge portion N that performs the shear cutting action of the prismatic blade tip end surface 18 does not rotate about the axis (axis 8a) of the prepared hole H. , The shape changes according to the shape (hexagonal) of the tip end surface 18 of the prismatic blade, and becomes maximum at each corner of the hexagonal peripheral edge.

As is apparent from the above operation, a fixed amount of forced feed per unit rotation angle is performed in the depth direction of the pilot hole H while the workpiece W is press-fitted into the pilot hole H and swings without rotating. As shown in FIG. 2A to FIG. 2C, the prismatic blade portion 17 to be cut is sheared around the prepared hole H into the contour shape of the tip end surface 18 of the prismatic blade portion, and the cross-sectional shape of the prepared hole H is The target rectangular hole WH is obtained by processing the prismatic blade tip end surface 18 into the contour shape (hexagonal shape). At this time, the chips that have been cut and removed from the periphery of the prepared hole H are deposited on the bottom of the prepared hole H, so that the depth of the prepared hole H is required in order to secure a deposition space for the chips. It must be deeper than the depth of WH. Specifically, as shown in FIG. 2, chips Wa are accumulated in a conical space Hb formed at the bottom of the prepared hole H at the tip conical portion of the prepared hole drill, and the accumulated chips are
It is desirable to press the tip surface 18 of the prismatic blade portion 17 that is press-fitted to the bottom of the prepared hole so as to be integrated with the work W.

The prismatic blade portion 17 of the square hole machining blade 4
The side surface of the prismatic blade portion 17 repeats the radial movement toward and away from the inner peripheral surface of the prepared hole H by the rotational swing motion of the prismatic blade portion 17, so that the side surface of the prismatic blade portion 17 is located inside the prepared hole H. Inclination is made at an angle slightly larger than the inclination angle of the shaft center 3a of the blade supporting shaft 3 with respect to the shaft center 8a of the held shaft 8 of the holder 2 so that the base 16 side becomes thinner. However, it is necessary to prevent the minimum diameter of the prismatic blade portion 17 from becoming too small and unduly reducing the strength.

In the above embodiment, the square hole machining tool 1 is attached to the rotary spindle 7 of the drilling machine to machine the fixed hole H of the fixed work W into a square hole. The work W is attached to the rotary spindle so that its prepared hole H is located concentrically with the rotary spindle. The tool holder is concentrically opposed to the rotary spindle and is movable toward and away from the rotary spindle in the axial direction. It is also possible to detachably hold the held shaft portion 8 of the square hole machining tool 1 in the (tailstock) in a concentric state with the rotary spindle and to use it. In this case, the workpiece W is rotationally driven around the axis of the pilot hole H with respect to the square hole machining tool 1, and the prismatic blade portion 17 of the square hole machining tool 1 is inserted into the pilot hole H of the rotating workpiece W. Will be press-fitted.

In the above embodiment, the hexagonal hole used as a wrench hole is machined so that the cross-sectional shape of the prismatic blade portion 17 is a regular hexagon, but the machined hole is not limited to a hexagonal hole. . Further, the square hole machining blade 4 may be integrally formed at the tip of the blade supporting shaft body 3. Furthermore, the peripheral edge of the opening of the prepared hole H provided in the work W is chamfered,
Although the prismatic blade portion 17 of the square hole machining tool 1 is easily centered with respect to the prepared hole H, it is needless to say that the square hole machining can be performed without trouble even without the chamfered portion Ha.

[0018]

As described above, the square hole drilling tool of the present invention has a rotary spindle that is movable toward and away from the fixed workpiece in the axial direction or a spindle for holding the workpiece. It is attached via a holder to a tool holder that is relatively movable toward and away from each other in the axial direction, and the tool or work is driven to rotate by a rotary spindle, and the tool and the work are moved relatively closer to each other, By relatively press-fitting the prismatic blade portion of the blade for square hole machining into the prepared hole provided in advance in the work, the prismatic blade portion that cannot relatively rotate with respect to the work, the center of the tip surface is A rotary swing motion is performed around the rotary swing motion, and the peripheral surface of the tip end surface of the prismatic blade is shear-cut in the peripheral surface of the prepared hole in the prepared hole depth direction. The cross-sectional shape of the prismatic It can be processed into a polygonal shape of the front end face of the part.

As described above, according to the tool for machining a square hole of the present invention, the rotary spindle that is movable toward and away from the fixed workpiece relative to the fixed workpiece or the workpiece-maintaining rotary spindle in the axial direction. Since it is used by being attached to a tool holder that can be moved toward and away from each other, general general-purpose machine tools such as drilling machines and lathes can be used as they are as square hole drilling equipment, and even lower Since it is only necessary to provide holes, it is possible to economically and efficiently process square holes for products in small lots.

According to the second aspect of the present invention, when the prismatic blade portion is worn or damaged, or when the polygonal rectangular hole is machined, only the square hole machining blade having the prismatic blade portion is used. Because it can be replaced, it is more economical than if the entire tool had to be replaced.

[Brief description of drawings]

FIG. 1 is a partially vertical front view showing the entire tool, FIG. 1B is a bottom view of the same tool, and FIG. 1C is a partially vertical front view showing an example of how to use the tool.

FIG. 2A is a partially longitudinal front view showing a workpiece pilot hole at the start of machining and a prismatic blade portion of the tool and a plan view showing the workpiece pilot hole, and FIG. 2B is a workpiece pilot hole during machining. And a prismatic blade part of the tool, which is a partial vertical front view and a transverse plan view,
The figure is a partially longitudinal front view showing a workpiece pilot hole and a prismatic blade portion of a tool at the end of machining and a plan view showing each machined hole.

FIG. 3 is a front view illustrating an operation of a prismatic blade portion.

FIG. 4 is a plan view illustrating an operation of a prismatic blade portion.

[Explanation of symbols]

 1 Tool for drilling each hole 2 Holder 3 Shaft body for supporting blade body 3a Shaft core for shaft body for blade body 4 Blade body for square hole processing 7 Spindle main spindle of drilling machine 8 Held shaft portion 8a Shaft core of held shaft portion (Axial core of the rotating main shaft 7) 9 Bearing portion 13 Blade attachment portion 16 Base of blade body for square hole processing 17 Square columnar blade portion of square blade processing blade 18 End surface of square columnar blade portion 18a Square columnar blade portion Center of tip surface W Work Wa Chip H Prepared hole Ha Chamfered portion of prepared hole Hb Conical space at the bottom of prepared hole

Claims (2)

[Claims] 1. A holder (2), a blade support shaft (3),
The holder (2) is equipped with a square hole cutting blade (4), and the holder (2) is a rotary spindle (7) or a workpiece-maintaining rotary spindle that can move toward and away from the fixed workpiece (W) in the axial direction. On the other hand, a tool holder that can be moved toward and away from each other relatively in the axial direction is provided with a held shaft portion (8) that is detachably held in a concentric state with the rotary spindle, and a blade support shaft body ( 3) is the shaft to be held in the holder (2)
(8) is rotatably supported by the holder (2) around an axis (3a) inclined with respect to the axis (8a), and the square hole machining blade (4) is The prismatic blade portion (17) protruding from the body (3) is provided, and the prismatic blade portion (17) is
It becomes thicker toward the tip side, and the center (18a) of the tip surface (18)
Is a square hole drilling tool located at an intersection (P) between the axis (8a) of the held shaft of the holder (2) and the axis (3a) of the blade support shaft (3). 2. A square hole machining blade body (4) which is detachably attached to a blade attachment portion (13) provided at the tip of the blade support shaft body (3). And the shaft body for supporting the blade body
A prismatic blade portion (17) protruding from (3) is provided.
Square hole drilling tool described in 1.