JP2000190118A - Shank-integral type end mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shank-integral type end mill which can cut favorably by shortening the length of a shank provided on the main body of the end mill, reducing its cost and preventing the generation of a vibration. SOLUTION: A long tapered part 3d is formed in the front of the main body 3 of an end mill holder 1 and a small outer diameter part 5b is provided on the rear part of the shank 5a of the main body 5 of the end mill 2 and the small outer diameter part 5b is shrinkage-fitted and fixed to the small diameter hole 3g formed on the tapered part 3d of the main body 3 and the step 5c provided on the front end of the small diameter part 5b is supported by the front end surface of the tapered part 3d and by shortening the length of the shank 5a provided on the main body 5 of the end mill 2 and increasing the rigidity, the generation of the vibration is prevented at the machining time by the cutting means 6 facing to the front end of the main body 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shank-integrated end mill used for cutting a die, for example.

[0002]

The conventional end mill is
As shown in FIG. 1, an end mill 1 is inserted into a straight hole 11c provided in a front cylindrical portion 11b of a holder main body 11a of the holder 11.
Long shank portion 12b in the shape of a round bar provided on the main body 12a
And a plurality of side lock members 13a, 13b are screwed into the front cylindrical portion 11b of the holder 11 from the outer peripheral side, and the shank portion 12b is pressed against the inner surface of the straight hole 11c by the inner ends thereof. In some cases, an end mill 12 was mounted on a holder 11. As shown in FIG. 2, the rear portion of the shank portion 12b of the cemented carbide main body 12a of the end mill 12 having a short shank portion 12b different from that shown in FIG. In some cases, the end mill 12 was fixed to the holder 11 by one-side constraint.

However, the front end of the shank portion of the above-mentioned conventional end mill protrudes forward from the holder, so that sufficient rigidity cannot be ensured, cutting performance is reduced during cutting, and vibrations such as pitching are reduced. There was a problem that it occurred. In addition, the conventional shrink fit chuck heats the holder, attaches and fixes the shank of the end mill,
When removing the shank portion of the end mill from the holder, the entire holder with the end mill is heated again to thermally expand the holder and remove the shank portion, so that the material of the holder is more thermally expanded than the material of the end mill. There is a problem that a material having a high coefficient of thermal expansion is used, and the holder and the end mill can use only metals having different coefficients of thermal expansion from each other.

The present invention solves the above-mentioned problems and reduces the cost by reducing the length of a shank portion provided in the main body of the end mill. Further, the present invention provides a shrink fitting hole provided in a front portion of the end mill holder. By making the entire outer surface of the small outer diameter portion of the shank portion of the end mill to be shrink-fitted and the entire surface of the step of the shank portion abut on the front end surface of the holder main body, rigidity is high, and during cutting processing, It is an object of the present invention to provide a shank-integrated end mill that does not generate vibration and can perform good cutting.

[0005]

According to a first aspect of the present invention, there is provided a shank-integrated end mill in which a long tapered portion is formed at a front portion of a holder body of an end mill holder, and a shrink fit is formed at a front end of the tapered portion. A hole is formed coaxially with the holder main body, and a small outer diameter portion is formed at a rear portion of a shank portion provided on the main body of the end mill, and the small outer diameter portion is shrink-fitted into a shrink-fitting hole of the holder main body. In addition, a step provided at the front end of the small outer diameter portion is supported by the front end surface of the tapered portion of the holder, and cutting means is provided at the front end of the main body.

According to a second aspect of the present invention, in the end mill with the shank according to the first aspect, a tapered portion is formed on a front side of a main step of the end mill, and a rear end of the tapered portion is formed on a holder body of the end mill holder. The outer diameter is smaller than the front end, and a cutting means such as a throw-away type ball tip is detachably attached to the front end of the main body of the end mill.

According to a third aspect of the present invention, in the shank integrated end mill according to the first or second aspect, the rear end of the main shank portion of the end mill is fastened by a draw bolt housed in the front portion of the holder body of the end mill holder. Things.

According to a fourth aspect of the present invention, in the end mill with a shank according to the first or second aspect, the end mill is formed on a threaded portion formed on an inner peripheral surface of a holder body of the end mill holder, and formed on an outer peripheral rear portion of a shank portion of the end mill. The male screw is tightened and fixed.

According to a fifth aspect of the present invention, there is provided an end mill integrated with a shank according to any one of the first to fourth aspects,
A groove is provided on the inner peripheral surface of the holder main body of the end mill holder at a front side of the holder main body to eject a fluid such as a coolant. According to a sixth aspect of the present invention, in the shank-integrated end mill according to any one of the first to fourth aspects, a small hole for ejecting a fluid such as a coolant to the front side of the holder main body is provided in the holder main body of the end mill holder. It is provided.

The invention according to claim 7 is based on claims 1-4 and 6
In the shank-integrated end mill described in any one of the above, an ejection angle changing member for regulating a fluid ejection direction is provided at a tip end of a small hole for fluid ejection formed along an axial direction of a holder main body of the end mill holder. It is assumed that.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. A shank-integrated end mill according to one embodiment of the present invention includes an end mill holder 1 and an end mill 2 as shown in FIG.

In the end mill holder 1, a tapered shank 3a is formed at the rear end of the holder body 3, and a flange 3b for automatic tool change is formed at an intermediate portion.
A b-shaped groove 3c is formed on the outer peripheral surface of b, and a long tapered portion 3d is formed on the front side of the flange portion 3b.

The holder body 3 has a female screw hole 3e, an intermediate hole 3f, a small diameter hole 3
g, a series of shrink-fitting holes 3h provided at the front portion and opening at the front end, and the axial centers of these holes are aligned with the holder body 3;
It is matched with the axis of. The tapered portion 3d is 5
It is tapered at an angle of about 6 ° to 6 °. The distal end of the pull stud 4 is fastened and fixed to the female screw hole 3 e of the holder body 3, and the pull stud 4 has a center hole 4 a penetrating therethrough.

The shank 5 of the main body 5 of the end mill 2
a, a small outer diameter portion 5b is formed in a round bar shape at the rear portion, and a front side portion 5d whose rear portion has a large outer diameter is provided at the front side of a step 5c provided at the tip end side of the small outer diameter portion 5b to be shrink-fitted. A cutting means 6 made of a throw-away type ball tip is detachably attached to a front end portion where a notch 5e of 5d is formed.

The small outer diameter portion 5 of the main body 5 of the end mill 2
As shown in FIG. 4, b is formed by adding a rear portion of the shank portion 5a to a small outer diameter, and the front side portion 5d of the main body 5 is more gentle than the tapered portion of the holder body 3 of the end mill holder 1. The taper is formed.

The end mill 2 is inserted into a shrink fitting hole 3h provided at the front of the holder body 3 of the end mill holder 1.
The small outer diameter portion 5b provided at the rear portion of the shank portion 5a of the main body 5 is shrink-fitted, and the entire surface of the step 5c of the shank portion 5a of the main body 5 is brought into contact with the front end surface 3A of the holder main body 3 of the holder 1. Thus, the holder main body 3 and the shank portion 5a of the end mill 2 are fixed to each other in a two-face constrained state.

Then, the external thread portion 7a of the draw bolt 7 is inserted into the small-diameter hole portion 3g from the rear side in the holder main body 3 of the end mill holder 1, and the screw hole 5f is formed in the rear portion of the main body 5 of the end mill 2 in advance. The main body 5 can be more firmly integrated with the holder main body 3 by screw-fitting and fastening.

In the present invention, as shown in FIG. 5, a female screw 3i is formed at the rear end of a shrink fitting hole 3h provided at the front of the holder body 3 of the end mill holder 1, and Male thread 5g preformed on the back of the main body 5
Is screwed into the female screw 3i and fastened,
The main body 5 can be fixed to the holder main body 3 without using the draw bolt.

As shown in FIG. 6, grooves 3j having a triangular or arc-shaped cross section are provided at a plurality of positions in the circumferential direction on the inner peripheral surface of the shrink fitting hole 3h of the holder body 3 of the end mill holder 1. The holder main body 3 is formed in the axial direction of the main body 3.
A gas or a liquid such as a coolant or a cutting fluid, that is, a fluid is ejected from a front end of the end mill holder 1. As shown in FIG. Holder body 3 at multiple locations
And a fluid such as a coolant may be ejected from the front end of the holder body 3.

The grooves 3j and the small holes 3 shown in FIGS.
For k, coolant or the like can be supplied by conventionally known means. Then, as shown in FIG. 8, a cylindrical shank 3 m is provided at the rear end of the holder body 3 of the end mill holder 1.
The tapered cone 8 is fitted between the large diameter flange 4b of the pull stud 4 and the flange 3b for automatic tool change, and the front end of the tapered cone 8 is connected to the flange 3b via a plurality of disc springs 9. The annular washer 10 is interposed at the rear end of the tapered cone 8. The configuration of the end mill shown in FIG. 8 other than that described above is the same as that shown in FIG.

As shown in FIGS. 9A and 9B, the tapered portion 3d of the holder body 3 of the end mill holder 1 is tapered.
In addition, small holes 3k are formed at a plurality of positions in the circumferential direction along the axial direction of the holder main body 3, and at the front end of the small holes 3k, a fluid such as a coolant is ejected, and the ejection angle is changed to regulate the ejection direction. The cylindrical bush 20 having an inclined angle may be fitted or screwed to the ejection hole 20a, which is a member, and may be fixed by screwing, so that a fluid such as a coolant is reliably ejected to the cutting member at the end mill end. This is particularly effective in the case where the diameter of the tip of the holder is small and it is not possible to form an ejection hole having an inclination angle for regulating the ejection direction at the fluid outlet of the small hole 3k.

Further, in the present invention, the cutting member which is a cutting means provided at the front end of the main body of the end mill can be appropriately changed without being limited to the ball chip.
A straight blade, a twist blade or the like may be integrally formed at the tip of the shank portion of the main body.

Further, by increasing the length of the tapered portion 3d provided on the holder body 3 of the end mill holder 1 as necessary, such as the one shown in FIG.
The outer diameter portion 5b of the shank portion 5a formed at the rear portion is formed into a tapered shape, and the length of the shank portion 5a is shortened to reduce the use of expensive long-end mills made of hard metal and can be provided at low cost. In addition, an end mill holder having high rigidity can be realized, and highly accurate machining can be performed.

When the die is machined, the angle connecting the outer circumference of the ball end mill, the outer circumference of the holder body of the end mill holder and the root of the holder is preferably smaller than the draft angle of the die. .

[0025]

As described above, the shank-integrated end mill according to the first aspect of the present invention can shorten the length of the shank provided on the main body of the end mill.
The use of expensive long size end mills can be reduced to reduce the cost, and the outer peripheral surface of the small outer diameter portion of the shank portion of the end mill to be shrink-fitted into the shrink-fitting hole provided in the front portion of the end mill holder and the shank portion By making the entire surface of the step a two-face constraint in which the entire surface of the step is brought into contact with the front end surface of the holder main body, rigidity is high, vibration is not generated at the time of cutting, and good cutting can be performed.

According to a second aspect of the present invention, a tapered portion is formed on the front side of the main step of the end mill, and the rear end of the tapered portion has a smaller outer diameter than the front end of the end mill holder. By performing the above-mentioned fastening, it is possible to perform the cutting work only by replacing only the throwaway tip without removing the end mill from the holder body one by one due to wear and the like, and the material of the end mill is A metal material having a different coefficient of thermal expansion from that of the holder is not used, and even if it is made of a hard metal, it can be used even if the holder has substantially the same coefficient of thermal expansion as HSS or the like.

According to a third aspect of the present invention, the rear end portion of the main body of the end mill is fastened by a draw bolt accommodated in the front portion of the holder main body of the end mill holder.
In the invention of the third aspect, since the male thread formed on the outer peripheral rear portion of the shank portion of the end mill is tightened to the threaded portion formed on the inner peripheral surface of the holder body of the end mill holder, the invention according to the third and fourth aspects makes the cutting process more difficult. The invention of claim 3 can improve the rigidity more than the invention of claim 4, and the invention of claim 4 has a slightly lower rigidity than the invention of claim 3. Since it is not used, it can be easily manufactured.

According to the fifth, sixth and seventh aspects of the present invention, a groove is provided on the inner peripheral surface of the holder main body of the end mill holder, a small hole is provided in the holder main body, or the ejection angle fixed at the tip of the small hole. The ejection direction is regulated by the member, and a fluid such as coolant is ejected to the front side of the holder body, so that it is possible to cool the workpiece and prevent the adhesion of chips, etc. as necessary during machining. ,preferable.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing an example of a conventional end mill.

FIG. 2 is a partially cutaway side view showing another example of a conventional end mill.

FIG. 3 is a partially cutaway side view of the shank integrated end mill according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram of a main body of the shank integrated end mill shown in FIG. 3;

FIG. 5 is a longitudinal sectional side view of a modification of the fastening portion of the shank integrated end mill.

FIG. 6 is a front end view of a main body of the shank-integrated end mill.

FIG. 7 is a front end view showing a modification of the main body of the shank-integrated end mill.

FIG. 8 is a partially cutaway side view of a modification of the shank integrated end mill shown in FIG. 3;

9A is a modification of the fastening portion of the shank-integrated end mill, and FIG. 9B is a longitudinal sectional side view taken along line AA of FIG. 9B, and FIG. 9B is a front end view of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 End mill holder 2 End mill 3 End mill holder holder main body 3a Taper shank part 3b Flange part 3d Tapered taper part 3e Female thread part 3f Intermediate hole part 3g Small diameter hole part 3h Shrink fitting hole part 3i Female screw 3k Small hole 3j groove 3m shank Part 4 Pull stud 5 End mill main body 5a Shank part 5b Small outer diameter part 5c Front part 5e Notch 5f Female screw hole 6 Cutting means 7 Draw bolt 7a Male thread part 8 Taper cone 9 Disc spring 20 Cylindrical bush (spout angle changing member ) 20a orifice

Continued on the front page (72) Inventor Yusaku Yamamoto 1-6-153 Motomachi, Higashiosaka-shi, Osaka F-term in Niken Kousaku Co., Ltd. (reference) 3C022 KK01 KK11

Claims (7)

[Claims] 1. A shank provided in a main body of an end mill, wherein a long tapered portion is formed at a front portion of a holder main body of an end mill holder, and a small diameter hole opening at a front end of the tapered portion is formed coaxially with the holder main body. A small outer diameter portion is formed at a rear portion of the holder body, and the small outer diameter portion is shrink-fitted and fixed in a shrink-fitting hole of the holder body, and a step provided at a front end of the small outer diameter portion is provided with a step of the holder body. A shank-integrated end mill, wherein the end mill is supported on a front end surface of a tapered portion, and cutting means is provided on a front end portion of the main body. 2. A taper portion is formed on the front side of the main step of the end mill, the rear end of the taper section is made smaller in outer diameter than the front end of the holder body of the end mill holder, and a throw-away type is provided on the front end of the main body of the end mill. 2. A cutting means such as a ball tip is detachably mounted.
The shank-integrated end mill described in 1. 3. A shank-integrated end mill according to claim 1, wherein a rear end of a main shank portion of the end mill is fastened by a draw bolt housed in a front portion of a holder main body of the end mill holder. 4. The end mill holder according to claim 1, wherein a male thread formed on an inner peripheral surface of a holder body of the end mill holder is formed by tightening a male thread formed on a rear end of an outer periphery of a shank of the end mill. End mill with shank. 5. The end mill holder according to claim 1, wherein a groove for ejecting a fluid such as a coolant is provided on an inner peripheral surface of the holder main body in front of the holder main body. End mill with shank. 6. The shank according to claim 1, wherein a small hole for ejecting a fluid such as a coolant is provided in a front side of the holder main body in the holder main body of the end mill holder. Integrated end mill. 7. An end angle holder provided at an end of a small hole for ejecting fluid formed along an axial direction of a holder body of an end mill holder, the ejection angle changing member for regulating a fluid ejecting direction. And a shank-integrated end mill according to any one of claims 6 and 7.