JP2002018608A - Cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an economical cutting tool wherein a head 6 is mounted detachably at the tip of a shank 1 and which can continue cutting operation without changing the shank 1 even if the tip of the shank 1 is broken caused by the excessive load during cutting. SOLUTION: A head side mounting section is formed at the rear end of the head 6, at the tip of which a cutting edge 8 is provided, and shank side mounting sections to which the head side mounting section can be mounted are formed at both ends of the shank 1, and either the head side mounting section or shank side mounting sections are provided with hole sections 2 provided with a tapered face which becomes smaller in diameter toward the bottom of the hole, and the other mounting section is provided with a projected section 11 having a tapered face capable of contacting the former tapered face closely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool in which a head provided with a cutting edge at a tip is detachably attached to a tip of a shank.

[0002]

2. Description of the Related Art Japanese Patent No. 27
In Japanese Patent No. 14334, a convex portion having a tapered surface whose diameter gradually decreases toward the rear end side is formed at a rear end portion of a head having a tip attached to a tip and a cutting blade, and a hollow shaft-shaped portion. At the tip of the shank, a hole having a tapered surface that gradually decreases in diameter toward the bottom of the hole that can be in close contact with the protrusion is formed. After inserting the protrusion into the hole, the hollow portion of the shank is formed. By screwing a bolt inserted from the rear end into the head into the head, the head is pulled to the rear end side, the tapered surface of the convex part and the hole is brought into close contact, and the head is attached to the shank tip is proposed Have been. However, according to such a cutting tool, the head can be firmly attached to the shank by the close contact of the tapered surface between the hole and the convex portion, and by preparing various types of heads and exchanging them, Various shavings can be handled with one shank.

[0003]

However, in the above-mentioned conventional cutting tool, the above-mentioned hole is formed only at the tip of the shank. If the tip is broken, the cutting operation cannot be continued unless the broken shank is discarded and replaced with a new shank, which is uneconomical. In addition, in this conventional cutting tool, the head is attached and detached by tightening bolts on the rear end side of the shank.For example, if the shank is held by a cylindrical holder, the head is replaced as it is. In addition, even if an attempt is made to supply the cutting fluid from the machine tool side to the cutting blade side through the inside of the shank, since the bolt is inserted into the hollow portion of the shank and is closed, external There is also the problem of having to rely on refueling.

The present invention has been made in view of such circumstances, and in a cutting tool in which a head is detachably attached to the tip of the shank as described above, the tip of the shank is damaged due to an excessive load or the like during cutting. The purpose of the present invention is to provide an economical cutting tool that can continue the cutting operation without changing the shank even if the shank is replaced. The second purpose is to provide a replaceable cutting tool,
It is a third object of the present invention to provide a cutting tool capable of supplying a cutting fluid from a machine tool through a shank through internal lubrication.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to attain the first object, the present invention provides a head mounting method in which a cutting edge is provided at a front end of a head. And a shank-side mounting portion to which the head-side mounting portion can be mounted at both ends of the shank. One of the head-side mounting portion and the shank-side mounting portion is connected to the hole bottom side. And a hole having a tapered surface that gradually reduces in diameter as it goes toward, and the other mounting portion is a projection having a tapered surface that can be in close contact with the tapered surface. Thus, by forming the shank-side mounting portion to which the head-side mounting portion can be mounted at both ends of the shank, even if the shank-side mounting portion at one end is damaged, the shank is turned over and the other end is formed. Shank side mounting part provided on It is possible to continue cutting operation by attaching the head.

When the head is mounted on the shank in such a cutting tool, for example, the shank is formed in a hollow shape as in the conventional cutting tool described in the above-mentioned publication, and a shank-side mounting portion at one end thereof is provided. May be attached to the head attached to the head by screwing in the bolt inserted from the other end side, but in this case, one of both ends of the shank is broken or deformed. For example, when the head is damaged, the head attached to the other end may not be able to be pulled in with bolts. Therefore, in order to solve such inconvenience, a mounting hole for pulling the head toward the shank side by screwing a mounting screw from the outer peripheral side in a state where the head side mounting portion and the shank side mounting portion communicate with each other is provided. It is desirable to form each of them, so that even if the shank is held by the cylindrical holder, the head can be replaced without removing the shank one by one. Further, while the shank is formed in a hollow shape as described above, when the head is formed with a through hole communicating with the hollow portion of the shank and opening toward the cutting blade, the head is formed through the hollow portion. The cutting fluid can be supplied to the cutting blade side through the hole, so that the cutting blade can be efficiently cooled and the cutting resistance can be reduced.

[0007]

1 and 2 show a first embodiment of the present invention.
1 shows an embodiment of the present invention. In this embodiment, the shank 1 is formed of a hard material such as a cemented carbide in a substantially cylindrical shaft shape.
Hole portions 2 each having a tapered inner peripheral surface whose diameter gradually decreases at an equal taper angle toward the opposite end side, that is, toward the bottom of the hole, with respect to the center axis X of the present embodiment. It is a shank side mounting portion in the form. In addition, between these holes 2, 2, an axis X
A through hole 3 is formed so as to communicate the bottoms of the two holes 2 and 2 with each other, so that the shank 1 is formed in a hollow shaft shape by the through hole 3.

Further, mounting holes are formed at both ends of the shank 1 so as to open from the outer peripheral surface of the shank 1 to the inner peripheral surface of the hole 2 at positions equal to each other in the direction of the axis X from both end surfaces of the shank 1. 4 are formed respectively. The mounting hole 4 is formed in a tapered surface shape in which the opening on the outer peripheral surface side of the shank 1 gradually decreases in diameter toward the inner peripheral side. The shank 1 has the same diameter, and its center line Q is arranged to extend in a direction orthogonal to the axis X of the shank 1. On both end surfaces of the shank 1, concave grooves 5 having a semicircular cross section are formed so as to extend between the outer peripheral surface of the shank 1 and the hole 2 in a direction also orthogonal to the axis X. ing.

On the other hand, the head 6 is formed of a steel material or the like, and a tip mounting seat 7 is formed at the tip of the head 6. The tip mounting seat 7 is clamped with a throw-away tip 9 having a cutting edge 8 formed thereon. It is detachably attached by a screw 10. Further, at the rear end of the head 6, a convex portion 11 having a tapered outer peripheral surface whose diameter is gradually reduced toward the rear end side is formed as a head side mounting portion.
The taper angle of the tapered surface formed by the outer peripheral surface of the convex portion 11 is equal to the taper angle of the tapered surface formed by the inner peripheral surface of the hole 2. Then, in a state where the convex portion 11 is inserted into one of the holes 2 of the shank 1 and the tapered surfaces thereof are brought into close contact with each other, the end surface of the shank 1 on the side where the hole 2 is formed and the end surface A slight gap is formed between the annular surface around the convex portion 11 of the head 6 and the annular surface, which can be engaged with the concave groove 5 in this close contact state. Ridge 12 having a convex semi-circular cross section
Are formed to extend in a direction perpendicular to the axis X.

Further, on the outer peripheral surface of the convex portion 11 of the head 6, the convex portion 11 is inserted into the hole portion 2 as described above while the ridge 12 is engaged with the concave groove 5, and the taper is formed. In a state where the surfaces are brought into close contact with each other, a mounting screw hole 13 having a center line P extending in a direction orthogonal to the axis X is formed as a mounting hole on the head 6 side at a position where the mounting hole 4 communicates. ing. However, this mounting screw hole 13
The inner diameter of the mounting hole 4 is slightly smaller than that of the mounting hole 4, and the center line P is located slightly closer to the tip end of the head 6 than the center line Q of the mounting hole 4 on the shank 1 side in the close contact state. It is eccentric. A supply path 14 for the cutting fluid is formed from the rear end surface of the convex portion 11 of the head 6 to the rear end side of the tip mounting seat 7, and is opened toward the cutting blade 8 of the indexable insert 9. Have been.

In the head 6 constructed as described above, the ridge 12 is engaged with the concave groove 5 as described above, and the projection 11 is formed in the holes 2 and 2 formed at both ends of the shank 1. After being selectively inserted into one of the mounting holes, the mounting screw 15 having a dish-shaped head is passed through the mounting hole 4 and the mounting screw hole 12 is inserted.
, The head of the mounting screw 15 comes into close contact with the tapered surface on the opening side of the mounting hole 4 with the eccentricity of the center lines P and Q, and the head 6 is mounted on the shank 1 side. The tapered surface of the projection 11 is brought into close contact with the tapered surface of the hole 2 so as to be drawn into the hole 2, and is firmly fixed to the hole 2 in the same manner as the above-mentioned conventional cutting tool. Further, in this state, the through hole 3 of the shank 1 is communicated with the supply path 14 of the head 6, and through the hole 2 at the other end where the head 6 of the shank 1 is not attached from the machine tool side. A cutting fluid can be supplied.

In the cutting tool configured as described above, an excessive load is applied during the cutting process, so that the shank 1 is mounted at one end where the head 6 is mounted.
Even if the shank 1 is damaged, the shank 1 is turned over and re-attached to the machine tool, and the head 6 is attached to the other end where no damage has occurred, so that the cutting operation can be continued without replacing the shank 1. be able to. Therefore, even if such damage occurs, the relatively expensive cemented carbide shank 1 can be effectively used without being discarded, so that it is economical and such damage is taken into account. It is not necessary to prepare the shank 1 more than necessary in advance, and efficient work can be achieved.

In this embodiment, when the head 6 is mounted on the shank 1, the mounting hole 4 is formed on the shank 1 side and the mounting screw hole 12 is formed on the head 6 as the mounting hole. 6 is inserted into the hole 2 of the shank 1 and the mounting screw 15 is screwed into the mounting screw hole 12 through the mounting hole 4 so that the head 6 is drawn into the shank 1 as described above. Although it is fixed, for example, like the above-mentioned conventional cutting tool, a clamp bolt is inserted through the through hole 3 from the end of the shank 1 to which the head 6 is not attached, and is inserted into the rear end of the convex portion 11 of the head 6. Alternatively, the head 6 may be fixed by being screwed into the shank 1. However, with such an attachment method,
If one end of the shank 1 is broken, this end must be re-formed so as to be perpendicular to the axis X, and if the shank 1 is attached to a cylindrical holder, When the head 6 is to be replaced even during the machining, the shank 1 must be removed from the holder each time, so that the operation cannot be complicated. In the part 11 and the hole 2 as a shank side mounting part,
It is desirable to form a mounting hole 4 and a mounting screw hole 12 for pulling the head 6 toward the shank 1 by screwing the mounting screw 15 from the outer peripheral side while communicating with each other.

In this embodiment, the through hole 3 is formed in the shank 1 even though the head 6 can be attached without using a clamp bolt as described above. A supply path 14 for the cutting oil is formed, which communicates with the hole 3 and opens toward the cutting edge 8 of the throw-away tip 9, and the shank 1 is held through the through-hole 3 and the supply path 14. Since the cutting fluid can be supplied from the machine side, it is possible to reliably and efficiently supply the cutting fluid to the cutting edge 8, and to sufficiently promote cooling of the cutting edge 8 and reduction of cutting resistance. Can be. However, in this regard, even when the head is attached with the clamp bolt as described above, for example, a supply hole for the cutting oil is provided in the clamp bolt, or the clamp bolt is thinner than the through hole of the shank. Although it is possible to form a supply path having an annular cross section as a diameter and communicate with the supply path of the head, in the former case, the supply hole is often provided through the entire length of the bolt. In the latter case, the rigidity of the clamp bolt may be impaired due to the reduced diameter of the clamp bolt.
Therefore, also in this case, the mounting holes 4
And the mounting screw hole 12 with the convex portion 11 of the head 6 and the shank 1
The head 6 is drawn into the shank 1 side by screwing the mounting screw 15 from the outer peripheral side in a state where these are communicated with each other, and the through hole 3 of the shank 1 and the head 6 are formed. It is desirable to supply the cutting oil via the supply path 14.

Next, FIGS. 3 and 4 show a second embodiment of the present invention. Components supplied to the first embodiment shown in FIGS. 1 and 2 have the same reference numerals. To simplify the description. That is, in this embodiment, a hole 21 having a tapered surface that gradually decreases in diameter toward the hole bottom side, that is, toward the distal end side, is formed as a head-side mounting portion on the head 6 side, while both ends of the shank 1 are formed. Are characterized in that, as shank-side mounting portions, convex portions 22, 22 each having a tapered side surface that can be in close contact with the tapered surface of the hole portion 21, are formed. Also in the second embodiment, the head 6 and the shank 1 are formed in the mounting holes 4 and the mounting screw holes 12 communicating with each other.
When the screw 5 is screwed in, the head 6 is drawn into the shank 1 and fixed. Further, the shank 1 is formed with a through hole 3 opening at the tip of the projections 22 at both ends thereof, and the head 6 communicates with the through hole 3 and opens toward the cutting blade 8. 14 are formed.

Therefore, the same effects as in the first embodiment can be obtained in the cutting tool having the above-described configuration. Moreover, in the second embodiment, the protruding portions 22, 22 are formed on the shank 1 made of cemented carbide, and the hole portion 21 is formed on the side of the head 6 made of steel. Since it is only necessary to provide a relatively soft steel head 6 to machine the hole which is difficult to machine by machining, this machining is easy and the tip of the shank 1 made of a cemented carbide having high rigidity is cut as a projection 22. The effect can be obtained that the tool can be extended closer to the blade 8 and the rigidity of the tool during cutting can be improved.

[0017]

As described above, according to the present invention,
With shank side mounting parts at both ends of the shank,
The head has a head-side mounting portion, and one of these mounting portions is a hole having a tapered inner surface and the other is a convex portion which can be in close contact with the tapered surface. While securing the mounting rigidity, even if the shank side mounting part should be damaged, cutting work can be continued using the mounting part on the opposite side, and effective use of the shank is promoted and economical processing is promoted. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a side view showing a first embodiment of the present invention.

FIG. 2 shows a shank 1 and a head 6 according to the embodiment shown in FIG.
It is an expanded sectional view which shows the attachment part.

FIG. 3 is a side view showing a second embodiment of the present invention.

FIG. 4 shows a shank 1 and a head 6 of the embodiment shown in FIG.
It is an expanded sectional view which shows the attachment part.

[Explanation of symbols]

 Reference Signs List 1 shank 2 hole (shank side mounting portion) 3 through hole 4 mounting hole 5 concave groove 6 head 8 cutting edge 11 convex portion (head side mounting portion) 12 ridge 13 mounting screw hole (mounting hole) 14 supply of cutting oil Road 15 Mounting screw 21 Hole (Shank side mounting part) 22 Convex part (Head side mounting part)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuhiko Kawade 1528 Nakashinda, Yokoi, Kobe-cho, Anpachi-gun, Gifu Prefecture F-term in Mitsubishi Materials Corporation Gifu Works 3C046 KK01 KK12 KK13 KK13

Claims (3)

[Claims] 1. A head-side mounting portion is formed at a rear end of a head provided with a cutting blade at a tip, and a shank-side mounting portion to which the head-side mounting portion can be mounted is formed at both ends of a shank. Of the head-side mounting portion and the shank-side mounting portion, one of the mounting portions is a hole portion having a tapered surface whose diameter gradually decreases toward the bottom of the hole, and the other mounting portion is in close contact with the tapered surface. A cutting tool characterized by being a convex part having a possible tapered surface. 2. The head-side mounting portion and the shank-side mounting portion are provided with mounting holes for drawing the head toward the shank side by screwing mounting screws from an outer peripheral side in a state of being connected to each other. The cutting tool according to claim 1, wherein: 3. The shank is formed in a hollow shape, while the head is formed with a through hole communicating with the hollow portion of the shank and opening toward the cutting blade. The cutting tool according to claim 1 or 2, wherein a cutting fluid can be supplied to the cutting edge side via the cutting tool.