JPH09267201A - Tool unit, and throw-away tip and tip holder used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool unit capable of cutting efficiently the inner diameter with the formation of a stepped part and rib part and further easily replacing tips. SOLUTION: A tool unit 1 is provided with a tip holder 2 and a throw-away tip 3 attached removably to the tip holder 2, advanced or retreated relatively to the inner diameter part of a workpiece W along the axial direction while cutting the inner diameter part K of the workpiece W rotated around the axis. The throw-away tip 3 is formed integrally with a first edge part 4 for the inner diameter part k in the advance to the workpiece W and a second edge part 5 for similarly cutting the inner diameter part K in the retreat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool unit for cutting an inner diameter of a work, a throw-away tip and a tip holder used for the tool unit.

[0002]

2. Description of the Related Art For example, when performing inner diameter cutting of a cylindrical work piece, while rotating the work piece around the axis, a cutting tip attached to a shank is applied to the inner diameter surface, and this is applied in the axial direction. Cutting is performed by advancing or retracting. Here, as shown in FIG. 8A, inner diameter cutting is performed so that stepped portions or rib portions R1 and R2 protruding inward from the inner diameter surface are formed at both axial end portions of the work W. If desired, it is necessary to perform cutting while advancing the tip when forming the rib portion R1 at the back of the shank, and it is necessary to perform cutting while retracting the tip when forming the front rib portion R2. . Therefore, two types of chips C1 and C2 for forward and backward are required. Further, as shown in FIG. 2B, even when the rib portion Rm is formed at the axially intermediate portion of the inner diameter surface, it is necessary to cut both sides of the rib portion Rm with separate chips C1 and C2.

[0003]

Conventionally, the chips C1 and C2 as described above have separate shanks S1 and S2, respectively.
It was attached to and used while replacing it as appropriate,
There is a drawback that it takes time to replace the shank. Therefore, as disclosed in, for example, Japanese Unexamined Patent Publication No. 5-154703, the above-mentioned two types of tips can be attached to a common shank so that cutting during forward movement and cutting during backward movement can be performed successively. Tools that have been made are also proposed. However, since these tools have a structure in which the tip is integrated with the shank by brazing, etc., if the tip has to be replaced due to the end of its life, etc. Melt and remove the old tip,
Instead, the new tip must either be re-bonded by brazing, or the tip replaced with the shank. In this case, the tip replacement work is troublesome in the former case, and the shank is wasted every time in the latter case, which is uneconomical.

An object of the present invention is to provide a tool unit which can efficiently perform inner diameter cutting accompanied by formation of a step portion and a rib portion, and can easily replace a tip, and a throw-away tip and a tip holder used therefor. To provide.

[0005]

In order to solve the above-mentioned problems, a tool unit of the present invention is mounted on a tip holder and on the tip holder in a detachable manner so that it can be attached to the inner diameter portion of a workpiece. On the other hand, a throw-away tip that cuts the inner diameter of the workpiece that rotates around the axis while moving forward or backward relative to the tip holder along the axial direction is provided. It is characterized in that a first blade portion that cuts the inner diameter portion when moving forward with respect to the object and a second blade portion that cuts the inner diameter portion when moving backward are integrally formed.

In the above tool unit, the throw-away tip, in which the blade for forward cutting and the blade for backward cutting are integrally formed, is configured to be attached to and detached from the tip holder. It is possible to efficiently perform inner diameter cutting accompanied by formation of ribs and ribs, and it is easy to replace tips.

Specifically, a screw insertion hole is formed so as to penetrate the throw-away tip, and the screw member inserted in the screw insertion hole is screwed into the tip end portion of the tip holder, whereby the throw-away tip is chipped. It can be configured to be attached to and detached from the holder. This further facilitates tip replacement. Further, the throw-away tip can be configured such that the first and second blade portions are formed in a symmetrical positional relationship with respect to the central axis thereof and in directions opposite to each other in the direction along the central axis. This allows
The inner diameter cutting accompanied by the formation of the step and the rib can be performed more efficiently and smoothly.

Next, the tip holder can be constructed so that the dimension of its axial cross section is larger in the predetermined direction that does not interfere with the notch of the throw-away tip into the workpiece than in other directions. As a result, the rigidity of the tip holder when a lateral force is applied to the axis can be increased, which in turn can improve the cutting accuracy. In this case, the axial section has a shape in which at least one side in the predetermined direction projects to the outside of the throw-away tip, and the projecting portion at the tip of the tip holder prevents rotation of the throw-away tip around the axis. A stopper portion can be formed. This makes it possible to prevent the rotation of the tip while increasing the rigidity of the tip holder and further improve the cutting accuracy. Further, if the axial cross section of the tip holder has an outer shape in which both sides thereof in the predetermined direction are arcuate bulges outward, the axial cross section of the outer shape can be easily obtained by turning or the like. As a result, the chip holder can be manufactured efficiently.

The present invention also provides a throw-away tip and a tip holder used in the above tool unit. The configuration corresponds to the extraction of each requirement relating to the indexable insert and the tip holder from the tool unit.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below with reference to the examples shown in the drawings. FIG. 1 shows a tool unit 1 according to an embodiment of the present invention, which includes a tip holder 2 and a throw-away tip 3 detachably attached to the tip holder 2. The tip holder 2 includes a base end portion 2a having a circular cross section and a main body portion 2b formed integrally with the base end portion 2a on one side thereof, and the throw-away tip 3 is attached to the tip of the main body portion 2b. With
The base end portion 2a is fixed to a base or the like (not shown).

As shown in FIG. 3, the throw-away tip 3 is formed with a screw insertion hole 6 passing through it along the central axis C, and the screw member 7 inserted in the screw insertion hole 6 is inserted in the screw insertion hole 6. By screwing into the screw hole 8 formed at the tip of the chip holder 2, the central axis C is attached to the chip holder 2 in a positional relationship where the central axis C substantially coincides with the axis C ′ of the chip holder 2. Has become. Also, FIG.
As shown in FIGS. 2 and 2, the throw-away tip 3 has the first and second blade portions 4 formed so as to project outward from the outer peripheral portion thereof.
And 5 are formed. As shown in FIG. 2, the first and second blade portions 4 and 5 are arranged in a symmetrical positional relationship with respect to the central axis C, and as shown in FIG. 1, in the direction along the central axis C. They are formed in opposite directions.

As shown in FIG. 5, the throw-away tip 3 is attached to the tip holder 2 so that the central axis C thereof is substantially parallel to the axis O of the workpiece W, and the axis O thereof. The inner diameter portion K of the workpiece W rotating around the axis O is cut by the first or second blade portion 4 or 5 while advancing or retracting along with the tip holder 2. Here, as shown in FIG. 2, the tip holder 2 has, in its axial cross section, a predetermined direction (hereinafter, referred to as a predetermined direction) that does not interfere with the cutting of the first and second blade portions 4 and 5 into the workpiece W.
Non-interference direction), specifically the first and second blades 4
The dimension of the blades 5 and 5 in the direction orthogonal to the projecting direction is larger than the dimension of the blades 4 and 5 in the projecting direction.

Further, both side portions of the tip holder 2 in the non-interference direction project outside the throw-away tip 3 to form projecting portions 9 and 10, and these projecting portions are formed on the tip surface of the chip holder 2. Stopper portions 11 and 12 projecting from the tip end face are formed on 9 and 10, respectively. The inner surfaces of these stopper portions 11 and 12 are flat surfaces 11a and 12a which are substantially parallel to each other, and as shown in FIG. 4, these engage with flat surfaces 3a and 3b formed on the outer peripheral surface of the throw-away tip 3, respectively. By doing so, rotation of the chip 3 around the central axis C is prevented. Further, as shown in FIG.
The axial cross section has a contour that is arcuate on both sides in the non-interference direction and bulges outward.

The method of using the tool unit 1 will be described below. FIG. 5 shows a stepped portion or rib portion R protruding inward from the inner diameter surface at both axial end portions of the workpiece W.
This is an example in the case of performing inner diameter cutting so that 1 and R2 are formed. That is, as shown in FIG. 4 (a), the tool unit 1 is positioned with respect to the inner diameter portion K in such a manner that the second blade portion 5 is brought into contact with the axially intermediate portion thereof, and then the work piece is cut. Rotate W. In this state, the tool unit 1 is laterally moved to cut the second blade portion 5 into the inner diameter portion K, and the tool unit 1 is retracted while continuing the rotation of the workpiece W, so that the inner diameter portion K The portion located on the front side of the tool unit 1 is cut to form a rib portion R2. When the cutting is completed, the tool unit 1 is laterally moved in the direction opposite to the above direction and further advanced in the axial direction as shown in FIG. It is moved to a position where it abuts on the front end portion of the inner diameter portion K of the cutting. Then, in this state, the tool unit 1 is moved forward while rotating the workpiece W in the same direction, so that the remaining inner diameter portion K is cut and the rib portion R1 is formed. Of course, the cutting by the first and second blade portions 4 and 5 can be performed in the reverse order of the above.

When the blades 4 to 5 are exhausted,
The throw-away tip 3 is replaced. In this case,
As shown in FIG. 3, the screw member 7 is removed, the old chip 3 is removed, a new chip is subsequently mounted, and the screw member 7 is screwed into the chip holder 2 again to complete the replacement.

Next, FIG. 6 shows an example in which inner diameter cutting is performed so that a step portion or rib portion Rm protruding inward from the inner diameter surface is formed in the axially intermediate portion of the workpiece W. . In this case, for example, the tool unit 1 is inserted into the inside of the workpiece W, and the second blade portion 5 is brought into contact with the inner diameter portion K on the inner end face side of the rib Rm to be formed. Position with. Then, the rotation of the workpiece W is started, and the tool unit 1 is retracted, so that the inner side of the inner diameter portion K is cut. Next, the tool unit 1 is retracted inside the inner diameter portion K and moved to the front end surface position of the workpiece W, and the tip of the first blade portion 4 abuts on the front end portion of the uncut inner diameter portion K. Move the tool unit 1 sideways to. Then, in this state, the tool unit 1 is moved forward while rotating the workpiece W in the same direction, whereby the remaining inner diameter portion K is cut and the rib portion Rm is formed.

In the throw-away tip 3, it is possible to form three or more blade portions.

The tip holder 2 is premised on that the throw-away tip 3 having the first and second blades 4 and 5 integrally formed therein is attached and detached, as shown in FIG. It can also be used for the purpose of holding a general throw-away tip 50, such as one in which only a single blade portion 4 is formed.

[Brief description of drawings]

FIG. 1 is a side view showing a tool unit as an embodiment of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a side view showing a method of attaching the throw-away tip to the tip holder.

FIG. 4 is a sectional view taken along line AA of FIG. 1;

5 is an explanatory view of a method of using the tool unit shown in FIG.

FIG. 6 is an explanatory view showing another way of using the same.

FIG. 7 is a side view showing another usage example of the tip holder.

FIG. 8 is an explanatory view showing a conventional inner diameter cutting method.

[Explanation of symbols]

 1 Tool Unit 2 Tip Holder 3 Throw-away Tip 4 First Blade 5 Second Blade 6 Screw Insertion Hole 7 Screw Member 8 Screw Hole 11, 12 Stopper W W Workpiece K Inner Diameter

Claims (8)

[Claims] 1. A tip holder, which is detachably attached to the tip holder and which moves forwards or backwards relative to the inner diameter of the work piece along with the tip holder along the axis of the workpiece while moving around the axis. Including a throw-away tip for cutting the inner diameter portion of the workpiece to be rotated, the throw-away tip, a first blade portion for cutting the inner diameter portion when advancing with respect to the workpiece, A tool unit, which is also integrally formed with a second blade portion that cuts the inner diameter portion when retracting. 2. The throw-away tip is formed by forming a screw insertion hole so as to pass through the throw-away tip, and screwing a screw member inserted through the screw insertion hole into the tip end portion of the tip holder. The tool unit according to claim 1, which is adapted to be attached to a holder. 3. In the throw-away tip, the first and second blades are formed so as to have a symmetrical positional relationship with respect to a central axis thereof and to be opposite to each other in a direction along the central axis. The tool unit described in 2. 4. The tip holder has a dimension of an axial cross section which is larger than other directions in a predetermined direction that does not interfere with a cut of the throw-away tip into the workpiece. Tool unit according to any one of. 5. An axial cross section of the tip holder has a shape in which at least one side in the predetermined direction projects to the outside of the throw-away tip, and the tip portion of the tip holder has the projecting portion at the tip of the throw-away tip. The tool unit according to claim 4, wherein a stopper portion is formed to prevent rotation of the away tip around the axis. 6. The tool unit according to claim 5, wherein an axial cross section of the tip holder has an outer shape which is an arc shape in which both sides thereof bulge outward with respect to the predetermined direction. 7. The object which is detachably attached to a tip holder and which rotates around the axis while moving forward or backward relative to the inner diameter of the work piece along with the tip holder along the axial direction thereof. While cutting the inner diameter portion of the work piece, a first blade portion that cuts the inner diameter portion when advancing with respect to the work piece, and a second blade portion that cuts the inner diameter portion when retreating as well. The throw-away tip is characterized by being integrally formed. 8. The inner diameter portion of the workpiece is rotated while advancing or retracting relative to the inner diameter portion of the workpiece while the inner diameter portion of the workpiece rotating around the axis is cut and the workpiece is cut. A throwaway tip integrally formed with a first blade portion that cuts the inner diameter portion when advancing with respect to an object and a second blade portion that cuts the inner diameter portion when retreating similarly.
It is designed to be removably attached to its own tip, and the dimension of its axial cross section in a predetermined direction that does not interfere with the notch of the throw-away tip into the workpiece,
A tip holder characterized by being made larger than the other directions.