JP2003225811A - Cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting tool capable of fixing cutting edge tips at accurate positions and preventing trembling or the like by positively attaching a cartridge in the cutting tool formed by attaching the cartridge provided with the cutting edge tips on a tool body. <P>SOLUTION: The cutting tool is formed by forming a recessed groove 17 on the tip part outer circumference of a substantially conical tool body 1 rotated around an axis O and attaching the cartridge 18 provided with the cutting edge tips 5B and 5C in the recessed groove 17. In the cartridge 18, a base end neighborhood is screwed by a set screw, and a tip is screwed by a tip fixing screw 24 from a tool body 1 side. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool most suitable for machining valve holes in a cylinder head of an engine.

[0002]

2. Description of the Related Art As a cutting tool of this type, the inventors of the present invention have proposed a cutting tool as shown in FIGS. 5 to 7, for example, in Japanese Patent Laid-Open No. 6-304804.
In these drawings, the tool main body 1 has a substantially conical shape, is attached to a main shaft end of a machine tool (not shown) via an adapter 2, and is rotated around its axis O for cutting. A bush 3 is attached to the tip of the tool body 1 along the axis O, and a hole drilling tool (not shown) such as a gun reamer is fitted into the bush 3 and the tool body is attached by the shaft 4. It is possible to move forward or backward with respect to 1. Furthermore, three cutting edge chips 5A, 5 are provided on the outer periphery of the tip of the tool body 1.
B and 5C are provided. These cutting edge chips 5A,
Of the 5B and 5C, the two cutting blade tips 5B and 5C are fixed to the tip of the cartridge 18. The cartridge 18 is mounted in the groove 17 formed on the outer peripheral portion of the tip portion of the tool body 1 by fixing the base end portion with a set screw. On the other hand, the remaining one cutting edge tip 5A is fixed to the tip of the cartridge 8 and is slidably attached along the generatrix direction of the cone formed by the tool body 1 when the slider 7 slides.

That is, in the tool body 1, along the direction of the conical generatrix, that is, in the direction oblique to the axis O,
As shown in FIGS. 5 and 6, the groove 6 is formed,
A slider 7 is mounted in the groove 6 so as to be slidable only along the groove 6, and the cutting blade tip 5A is attached to the slider 7.
It is removably attached to the tip of the cartridge 8 attached to the. Further, inside the tool body 1 and the adapter 2, mounting holes 1a and 2a are formed along the axis O, respectively, and the slide shaft 14 and the coupling member 15 are inserted into these holes 1a and 2a. The coupling member 15 is fitted into the mounting hole 1a via the key 15a and integrally rotatable with the tool body 1 around the axis O, and the slide shaft 14 is moved back and forth to move the shaft O inside the mounting hole 1a. It is possible to move back and forth. The concave groove 6 of the tool body 1 and the mounting hole 1a communicate with each other through a through hole 6c, while the slider 7 has a connecting pin 1 protruding through the through hole 6c into the mounting hole 1a.
6 is attached, and the slider 7 is connected to the coupling member 15 by inserting the tip of the connecting pin 16 into the oblique hole 15b of the coupling member 15, and the coupling member 15 is connected by the slide shaft 14. By advancing and retracting, the slider 7 slides in the concave groove 6 and slides the cutting edge tip 5A in a direction oblique to the axis O.

In order to machine the valve hole as described above by using the cutting tool having such a structure, the hole machining tool is mounted on the bush 3, and the shaft 4 pulls it toward the base end side of the tool body 1. , While feeding the tool body 1 around the axis O while feeding it in the direction of the axis O, first, by the two fixed cutting blade tips 5B and 5C, chamfers C and C are formed at the opening of the hole as shown in FIG. To do. It should be noted that FIG. 8 shows a rotation locus of the cutting blade tips 5A, 5B, 5C around the axis O, and a reference symbol S in the drawing indicates a burnt which is fitted to the peripheral edge of an opening such as a valve hole. It is a hard member such as bond gold. When the chamfers C and C are formed in this way, the tool body 1 is slightly retracted while the tool body 1 is being rotated, and then the slide shaft 14 is projected to advance the coupling member 15 forward, As described above, the slider 7 is slid through the connecting pin 16, the cutting blade tip 5A is moved along the movement locus R, and the tapered surface P is formed on the opening of the hole.
To form. Thereafter, while the tool body 1 is still rotated, the hole drilling tool is advanced by the shaft 4 and inserted into the valve hole, and the valve hole itself is finished.

[0005]

By the way, in the cutting tool constructed in this way, the cartridge 18 to which the two cutting blade tips 5B and 5C are attached is screwed in the vicinity of the base end portion with a set screw to make the tool body. It is fixed to No. 1 and the positions where it is clamped are separated from the cutting edges of the cutting blade tips 5B and 5C.
For this reason, a gap occurs between the bottom surface of the tip of the cartridge and the wall surface of the concave groove, so that the cartridge cannot be securely mounted and the cutting blade tips 5B and 5C cannot be fixed at accurate positions. There was a problem. Further, in the state of being fixed in this way, the cutting blade tips 5B, 5C
When the cutting is performed by the method described above, only the base end of the cartridge 18 is fixed.
8 is bent and chatter vibration is generated, which seriously impairs the cutting accuracy and shortens the life of the cutting blades 5b and 5c.

On the other hand, in order to prevent the occurrence of such chattering vibrations, in the case of a cutting tool in which the cutting blade tips 5B and 5C are directly attached to the tip of the tool body 1 without the cartridge 18, the tool body is When the tip mounting seat of No. 1 is damaged, the whole tool body 1 must be replaced.

The present invention has been made under such a background, and in the cutting tool having the above-mentioned structure,
An object of the present invention is to provide a cutting tool capable of securely mounting a cartridge, fixing a cutting edge tip at an accurate position, and preventing chatter vibration and the like.

[0008]

In order to solve the above-mentioned problems, a cutting tool according to the present invention has a concave groove formed in the outer peripheral portion of the tip of a substantially conical tool body rotated around an axis. In a cutting tool in which a cartridge having a cutting edge tip is mounted in the groove, this cartridge is screwed with a set screw in the vicinity of the base end, and the tip is fixed from the tool body side to the tip fixing screw. It is attached to the tool body by screwing.

Therefore, in the cutting tool constructed as described above, the tip portion of the cartridge is screwed from the tool body side with the tip fixing screw, so that there is a gap between the bottom surface of the tip portion of the cartridge and the wall surface of the groove. It is possible to securely mount the cartridge and accurately fix the cutting edge tip without causing the occurrence of chattering vibration during cutting due to bending of the cartridge.

Further, in the cartridge, a clamping screw is screwed into one end of a screw hole formed through the cartridge, and the clamping blade is pressed to attach the cutting blade tip to the tip of the cartridge. Is
In addition, the tip end of the cartridge is fixed to the tool body by screwing a tip end fixing screw from the tool body side to the other end of the screw hole.

Therefore, in the cutting tool constructed as described above, the tip end fixing screw and the clamp screw are screwed from both sides of the screw hole to share the screw hole, thereby saving space and processing the cartridge. The cost can be reduced by reducing the man-hours.

In the cartridge, a hole penetrating the cartridge is formed, and the tip fixing screw penetrates the cartridge from the tool body side and is screwed to the clamp piece, whereby the cutting edge tip is It is characterized in that it is attached to the tip of the cartridge and the tip of the cartridge is fixed to the tool body. Therefore, the clamp screw is unnecessary and the number of parts can be reduced.

Further, in the cartridge, a screw hole is formed along a direction inclined with respect to the bottom surface of the cartridge, and the tip end fixing screw is screwed into the screw hole from the tool body side. The cartridge tip is fixed to the tool body. Therefore,
The hole through which the fixing screw at the tip of the tool body penetrates becomes longer,
Since the rigidity of the portion pinched by the tip fixing screw is increased, the tip of the cartridge can be more firmly fixed.

[0014]

1 and 2 show a first embodiment of the present invention.
FIG. However, in this embodiment,
Except for the mounting structure of the cartridge 18 at the tip of the tool body 1, there is no difference from the conventional cutting tool shown in FIG. 5 to FIG. 7, and therefore, the same components as those of the conventional cutting tool are designated by the same reference numerals. However, description of parts not shown is omitted.

That is, in the first embodiment, as shown in FIGS. 1 and 2, the outer shape of the tool main body 1 is generally a conical shape centered on the axis O, and the base portion to the tip portion. Toward the large diameter cylindrical portion 1b and taper-shaped reduced diameter portion 1
c, a small diameter cylindrical portion 1d and a tapered tip portion 1e. A groove 17 is formed in the outer peripheral portion in parallel with the axis O from the base portion to the tip portion. This groove 17
Is provided with an opening 26 that communicates from the outer surface of the reduced diameter portion 1c toward the groove 17, and a screw hole 25 is engraved at a position facing the opening 26. A screw hole 27 is engraved from the outer surface of the columnar portion 1b toward the groove 17. Further, the tip of the groove 17 is formed to be slightly wider as a cutting blade tip mounting space 17b, and a cutout portion 17c is formed in a portion adjacent to the cutting blade tip mounting space. Furthermore, a through hole 28 is formed in the groove 17 from the outer surface of the small-diameter cylindrical portion 1d toward the groove 17.

In the groove 17, the cutting blade tip 5B,
The cartridge 18 to which 5C is fixed is attached.
The cartridge 18 has an elongated shape that conforms to the groove shape, a tip mounting seat 18b is formed on the upper surface of the tip portion, and a screw hole 18d penetrating from the tip mounting seat 18b to the base end side. Is formed, a set screw hole 29 is formed on the base end side of the screw hole 18d, and an inclined surface 18e is formed on the base end.

The cutting blade tips 5B and 5C are positive tips formed of a hard material such as cemented carbide into a substantially equilateral triangular plate shape, and are seated on a tip mounting seat 18b formed at the tip of the cartridge 18. Further, the clamp piece 18c is pressed against the clamp piece 18c, and the clamp screw 20 is tightened to press the clamp piece 20c so as to be detachably attached.

When the cartridge 18 is attached to the tool body 1, the adjusting screw 19 screwed into the screw hole 27 is brought into contact with the inclined surface 18e at the base end of the cartridge 18 so that the cartridge 18 is slightly moved in the direction of the axis O. Make adjustments. Then, the set screw is inserted through the opening 26, the set screw hole 29 of the cartridge 18 is inserted, and the set screw 25 is screwed into the set screw hole 25, whereby the cartridge 18 is attached to the tool body 1.
Further, the tip fixing screw 24 is attached to the tool body 1 of the through hole 28.
It is inserted from the side and screwed into the screw hole 18d, and the tip of the cartridge 18 is fixed to the tool body 1.

As described above, the tip fixing screw 24 and the clamp screw 20 can share the same screw hole. That is, from both sides of the screw hole 18d, the tip end fixing screw 2
By screwing 4 and the clamp screw 20, the tip of the cartridge 18 and the cutting blade tips 5B and 5C are fixed.

In order to machine the valve hole as described above with the cutting tool having such a structure, the tool main body 1 is rotated around the axis O while feeding in the direction of the axis O so that the two cutting edge tips 5B, 5C forms a two-step chamfer at the opening of the hole. Then slide the cutting edge tip 5A,
A tapered surface is formed between the two chamfers. Then, the valve hole itself is finished with a hole drilling tool.

In such a processing step, the cutting blade tips 5B and 5C are subjected to a load acting at the time of cutting, but since the cartridge 18 is firmly fixed by the tip end fixing screw 24, the tip of the cartridge 18 is fixed. Bottom of part 1
No gap occurs between the groove 8a and the groove wall surface 17a. In this way, the cartridge 18 is securely mounted, the cutting blade tips 5B and 5C are accurately fixed, and chatter vibration during cutting due to bending of the cartridge 18 is prevented. Further, since chatter vibration is prevented, machining accuracy is improved, and further, abrasion of the cutting blades 5b, 5c is suppressed, so that the life thereof is extended and high-precision machining can be performed for a long time. Is given. If the chip mounting seat 18b is damaged, only the cartridge 18 is replaced.

Further, a tip end fixing screw 24 screwed from the tool body 1 side and a clamp screw 20 for mounting the cutting edge chips 5B and 5C on the chip mounting seat 18b are formed penetrating the cartridge 18. Since the screw holes 18d are shared, the space at the tip of the tool is saved and the number of processing steps for the cartridge 18 is reduced.

Therefore, according to the first embodiment, the cutting edge tips 5B and 5C can be accurately fixed, chatter vibration can be prevented from occurring, and the processing accuracy can be improved. The life of the cutting blades 5b and 5c can be extended. Even if the chip mounting seat 18b is damaged, only the cartridge 18 needs to be replaced, which is economical. In addition, the tip portion of the tool can be made space-saving, and the cost can be reduced by reducing the processing man-hours of the cartridge 18.

FIG. 3 shows a second embodiment of the present invention. In the second embodiment, a screw hole is formed in the clamp piece 18c, and the tip end fixing screw 30 is attached to the cartridge 18. A hole is formed therethrough. Then, insert the tip fixing screw 30 from the tool body 1 side,
The tip of the cartridge 18 is fixed to the tool body 1 by penetrating the cartridge 18 and screwing it into the screw hole of the clamp piece 18c. In this embodiment, the tip fixing screw 30 is the cartridge 1
Fixing the tip of 8 and cutting tip 5B, 5C
Can be fixed. Therefore, the clamp screw 20 used in the first embodiment is unnecessary, and the number of parts is reduced.

FIG. 4 shows a third embodiment of the present invention. In the third embodiment, the tip end of the cartridge 18 is inclined along the direction inclined with respect to the bottom surface 18a. A screw hole is formed in the cartridge 18 and a through hole 28 is formed in the tool body 1 so that the part fixing screw 31 can be screwed and fixed to the tip of the cartridge 18. In this embodiment, the wall thickness between the screw head of the tip end fixing screw 31 and the cartridge 18 is increased and the through hole 28 of the tool body 1 is longer than in the first and second embodiments. Therefore, the rigidity of the portion pinched by the tip fixing screw 31 is increased, and the tip of the cartridge 18 can be more firmly fixed.

Incidentally, in the first to third embodiments, the cutting blade tip 5A slides as described above, and the cutting blade tips 5B, 5 are formed.
Although an example is shown for a cutting tool with C fixed, the present invention may be used for a cutting tool that does not have a sliding cutting edge tip. Further, the number of cutting edge chips used for the cutting tool may not be three.

[0027]

As described above, according to the present invention,
The cartridge with the cutting edge fixed to the tip portion is fixed to the tool body near the base end portion with a set screw, and the tip portion is screwed with the tip portion fixing screw from the tool body side. Can be mounted securely and the cutting edge tip can be fixed accurately. Therefore, it is possible to prevent chatter vibration and the like due to the load applied during cutting.

Further, since the tip end fixing screw is screwed from the tool body side to the other end of the screw hole of the clamp screw for fixing the cutting edge tip formed penetrating the cartridge, the tool tip end is space-saving. can do.

Further, since the tip fixing screw attaches the cutting blade tip to the cartridge tip and fixes the cartridge tip to the tool body, the number of parts can be reduced.

Further, since the tip end fixing screw is screwed along the direction inclined with respect to the bottom surface of the cartridge to fix the cartridge tip end to the tool body, the cartridge tip end can be more firmly fixed to the tool body. it can.

[Brief description of drawings]

FIG. 1 is an enlarged side view showing a periphery of a cartridge 18 according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line XX in FIG.

FIG. 3 is an explanatory diagram corresponding to a cross section taken along line XX of FIG. 1 in the second embodiment.

FIG. 4 is an explanatory diagram corresponding to a cross section taken along line XX of FIG. 1 in the third embodiment.

FIG. 5 is a front view of a conventional cutting tool as viewed from the tool tip side.

6 is an enlarged cross-sectional view taken along line YY in FIG.

FIG. 7 is an enlarged sectional view taken along line ZOZ in FIG.

8 is a diagram showing a rotation locus around the axis O of the cutting edge tips 5A, 5B, 5C in the conventional cutting tool shown in FIG.

[Explanation of symbols]

1 Tool body 5A, 5B, 5C Cutting edge tip 17 groove 18 cartridges 18d screw hole 20 Clamp screw 24 Tip fixing screw O Tool body 1 rotation axis

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akira Venus             1528, Nakashinden, Yokoi, Kobe-cho, Anpachi-gun, Gifu Prefecture             Address Mitsubishi Materials Corporation Gifu Factory             Within F-term (reference) 3C046 KK02

Claims (4)

[Claims] 1. A cutting tool in which a concave groove is formed on the outer circumference of the tip of a substantially conical tool body rotated about an axis, and a cartridge provided with a cutting edge tip is mounted in the concave groove, This cartridge is screwed near the base end with a set screw,
Further, the cutting tool is mounted on the tool body by screwing a tip end fixing screw from the tool body side to the tool body. 2. The cutting tool according to claim 1, wherein the cartridge is configured such that a clamp screw is screwed into one end of a screw hole formed by penetrating the cartridge, and the clamp piece is pressed to cut the cutting blade. The tip is fixed to the tip of the cartridge, and the tip of the cartridge is fixed to the tool body by screwing a tip fixing screw from the tool body to the other end of the screw hole. And a cutting tool. 3. The cutting tool according to claim 1, wherein the cartridge has a hole penetrating the cartridge, and the tip fixing screw penetrates the cartridge from the tool body side and is screwed to a clamp piece. A cutting tool characterized in that the cutting tip is attached to the tip of the cartridge and the tip of the cartridge is fixed to the tool body. 4. The cutting tool according to claim 1, wherein the cartridge has a screw hole formed along a direction inclining with respect to a bottom surface of the cartridge, and the tip fixing screw is provided from the tool body side. A cutting tool characterized in that the tip of the cartridge is fixed to the tool body by being configured to be screwed onto the tool body.