JP2827955B2 - Cutting tools - Google Patents

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 a valve hole in a cylinder head of an engine.

[0002]

2. Description of the Related Art In such a valve hole of a cylinder head, a valve frequently comes into contact with the periphery of the opening of the hole. Therefore, a hard member such as a sintered alloy is fitted into this portion to improve durability. I'm trying to get. Therefore, as a cutting tool for machining the valve hole, a tool provided with a hole machining tool such as a gun reamer for finishing the hole itself and a cutting edge tip for machining the periphery of the opening is used. Moreover, the opening is often formed in a tapered surface shape in accordance with the shape of the valve head, so that the cutting edge tip is positioned with respect to the rotation axis of the cutting tool so that such a surface can be cut. It is desirable to be mounted slidably in the oblique direction.

FIGS. 4 to 6 show an example of a conventional cutting tool used for machining such a valve hole. In these figures, the tool body 1 has a substantially conical shape, is mounted via an adapter 2 on a spindle end or the like of a machine tool (not shown), is rotated around its axis O, and is subjected to cutting. A bush 3 is mounted on the tip of the tool body 1 along the axis O. A shank of a hole machining tool (not shown) such as the above-mentioned gun reamer is fitted into the bush 3 to thereby insert the tool body 1. By finishing the hole machining tool while rotating the hole, the hole itself can be finished. The advance of the drilling tool is performed by a shaft 4 which is coaxially inserted into a slide shaft described later.

Further, three cutting blade tips 5 are provided on the outer periphery of the distal end of the tool body 1, and the cutting edges 5 are used to machine the above-mentioned peripheral edge of the valve hole. I have. However, only one cutting edge tip 5A is shown in FIG.
B and 5C are not shown. Here, among these cutting edge tips 5, the two cutting edge tips 5B and 5C are directly fixed to the tool body 1, while the one cutting edge tip 5A is slidable as described above. Installed. That is, a T-shaped groove 6 is formed in the tool body 1 along the direction of the conical generating line of the tool body 1, that is, along the direction oblique to the axis O as shown in FIG. The slider 7 is slidably fitted into the slider 7, and the cutting blade tip 5A is detachably fixed to the slider 7.

On the other hand, holes 1a and 2a are formed along the axis O inside the tool body 1 and the adapter 2, respectively, and the slide shaft 8 and the coupling member 9 are inserted into these holes 1a and 2a. Have been. The coupling member 9 is fitted into the hole 1a via a key 9a, whereby the tool body 1 and the coupling member 9 can rotate integrally about the axis O, and the slide shaft 8
Is allowed to advance and retreat in the hole 1a. Further, the T-groove 6 and the hole 1a of the tool main body 1 communicate with each other via a hole 6a opened on the bottom surface of the T-groove 6. The slider 7 passes through the hole 6a and the hole 1a
The slider 7 and the coupling member 9 are connected by fitting the tip of the connection pin 10 into the oblique hole 9 b formed in the coupling member 9. As the coupling member 9 advances and retreats via the slide shaft 8, the slider 7 slides along the T-shaped groove 6 so that the cutting edge tip 5A moves along the axis O.
To slide in a diagonal direction.

In order to perform the above-described machining of the valve hole with the cutting tool having such a configuration, a hole machining tool such as a gun reamer is mounted on the bush 3 and drawn into the base end side of the tool body 1 by the shaft 4. Then, the tool body 1 is rotated and feed is given in the direction of the axis O. First, as shown in FIG. 6, the edge of the valve hole formed in the work material S by the two cutting blade tips 5B and 5C. The chamfering of the parts C, C is performed. Next, after the tool main body 1 is once slightly retracted, the slide shaft 8 and the coupling member 9 are advanced while rotating the tool main body 1, and the cutting blade tip 5A is moved through the connecting pin 10 and the slider 7 in the figure. By sliding along the dashed line R direction, the above-described tapered surface P is formed on the periphery of the opening of the valve hole. Thereafter, the hole drilling tool is advanced by the shaft 4 while the tool body 1 is being rotated, and finishing inside the valve hole (valve guide hole) is performed.

In this type of cutting tool, a groove having a U-shaped cross section is formed in the tool body 1 in place of the T-groove 6, and a space between the opposing wall surface of the groove and the slider 7 is formed. In addition, various proposals have been made by the inventors of the present invention in which an interposing member such as a spacer or a wedge member is detachably attached. However, in such a cutting tool, the load acting via the slider during cutting and the wear on the tool main body side due to the sliding of the slider do not directly occur on the tool main body, but occur on the above-mentioned interposed member. By exchanging the members, it is possible to easily and quickly recover the mounting accuracy and the positional accuracy of the slider and maintain the processing accuracy. A spacer is interposed between one of the wall surfaces and the slider, and the slider and the spacer are engaged with each other by a serration groove or the like extending in the generatrix direction, and a slider is provided between the other wall surface and the slider. By interposing a wedge member or the like that presses against one wall surface side, it is possible to improve the mounting rigidity of the slider.

[0008]

By the way, in this cutting tool, cutting is first performed by the two cutting blade tips 5B and 5C fixed to the tool body 1 as described above, and then the slider 7 is slid. In order to cut the tapered surface P by advancing the cutting edge tip 5A along the above-mentioned generatrix, the slider 7 moves to a position retracted to the outer peripheral side in the T groove 6 when cutting by the cutting edge tips 5B and 5C. Therefore, on the tip side of the tool body 1, the slider 7 is
Are separated from the bottom surface of the. That is, at the time of cutting by the cutting blade tips 5B and 5C, a gap B is formed between the bottom surface of the T-slot 6 and the slider 7 as shown in FIG. Opening to the tip side of the main body 1, the cutting edge tips 5B, 5C
A situation occurs in which the chips generated by the above-mentioned process enter the T groove 6 from the gap B.

However, when the chips entering the T-slot 6 stay in the T-slot 6, the slider 7 is moved to the T-slot.
Even if it is attempted to advance along the groove 6, when the bottom surface portion of the slider 7 hits the staying chips, there is a possibility that the slider 7 cannot be further advanced. They had to be removed frequently, which inevitably complicated the work and reduced the work efficiency. Even if the fine chips are retained in the T-slot 6 even before the slider 7 cannot move forward,
When the slider 7 slides in this state, the wear of the T-groove 6 and the slider 7 is remarkably promoted, and the tool life is shortened. The result is that rattling occurs and processing accuracy is impaired. In particular, when cutting the above-described valve hole or the like, since the generated chips are also sintered alloys of high hardness, wear is further promoted. The same applies to the above cutting tool in which an interposition member is attached between the slider and the groove having a U-shaped cross section provided instead of the T groove.

The present invention has been made under such a background, and has penetrated between a slider and a concave groove such as a T-shaped groove or a U-shaped groove in which the slider slides. Chips can be quickly discharged, and it is possible to prevent the sliding of the slider due to the accumulation of the chips, and prevent wear and rattling due to biting of the chips. The purpose is to provide cutting tools.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to achieve the above object, the present invention provides a substantially conical tool body which is rotated around an axis, and has a concave along a generatrix of the cone. A groove is formed, and a slider having a cutting edge tip is slidably mounted along the groove in the groove, and is rotatable integrally with the tool body inside the tool body. And a cutting tool provided with a coupling member which is movable back and forth along the axis and engages with the slider to slide the slider. And at least one chip discharge hole which is opened on the outer periphery of the tool body.

[0012]

In the cutting tool having such a configuration, chips entering the gap between the groove and the slider from the front end side of the tool body pass through the chip discharge holes and pass through the bottom surface of the groove. From the outside of the tool body. Therefore, it is possible to prevent the swarf from staying in the groove. Here, it is desirable that the chip discharge hole is formed so as to be gradually separated from the rotation axis of the tool main body from the concave groove side toward the opening side of the outer periphery of the tool main body. By adopting such a configuration,
Due to the centrifugal force caused by the rotation of the tool body, the chips are forcibly sent out from the groove toward the outer peripheral side of the tool body and are quickly discharged.

It is desirable that the chip discharge hole is formed as a through hole having both ends opened to the outer periphery of the tool body, so that one end of the through hole is formed as the tool body rotates. A flow of air towards the other end occurs,
The chips are further forcibly sent out by this flow of air and are smoothly discharged. Further, when the slider is composed of a portion extending parallel to the axis supporting the cutting edge tip on the tool tip side and a portion sliding along the generatrix, the concave groove is also formed accordingly. After extending in the direction parallel to the axis at the tip end of the tool body, the tool body is formed so as to bend and extend along the generatrix. First, it is desirable that the concave groove be formed so as to communicate with the bent portion. That is, when the concave groove is bent as described above, the chips easily stay at the bent portion. Therefore, by providing a chip discharge hole in such a portion, the chips can be discharged more efficiently. Can be encouraged.

Further, the slider is preferably provided with a recess extending at least in a position facing the chip discharge hole in a state where the coupling member is advanced, in a direction in which the chip discharge hole is formed. Desirably, by adopting such a configuration, even when the coupling member is advanced in particular, it becomes possible to introduce the chip into the chip discharge hole and discharge the chip without causing biting through the recess. . The groove on which the slider slides may be a T-shaped groove like the cutting tool shown in FIGS. 4 and 5, and at least one of opposing wall surfaces of the groove and the slider may be provided between the slider and the slider. Although an interposition member such as a spacer or a wedge member may be removably attached thereto, when the interposition member is mounted in this manner, the chip discharge hole may be closed by the interposition member. It is desirable that the chip discharge hole be formed so as to penetrate through the interposition member and open at the bottom of the concave groove so as not to cause such a problem.

[0015]

1 to 3 show an embodiment of the present invention. In this embodiment, FIGS. 4 and 5 show a basic structure other than a concave groove, a slider and a chip discharge hole.
Are common to those of the conventional cutting tool shown in FIG. In these figures, the adapter 2, the cutting tip 5
B, 5C, the slide shaft 8 and the like are not shown.

First, the configuration of the concave groove and the slider in this embodiment will be described. In this embodiment, a pair of parallel grooves are used instead of the T-groove 6 of the conventional cutting tool shown in FIGS. A concave groove 11 having a U-shaped cross section defined by opposing wall surfaces 11a and 11b and a bottom surface 11c orthogonal to the wall surfaces 11a and 11b is formed. 2, a spacer 12 is provided on the wall surface 11a facing the T, and a wedge member 13 is provided on the wall surface 11b facing the rear side in the tool rotation direction T via the adjusting member 14. It is attached detachably. In the cross section including the axis O of the tool main body 1, the concave groove 11 is bent after extending in a direction parallel to the axis O at the tip end of the tool main body 1 as shown in FIG. It is formed so as to extend along the generatrix of the cone. And
A slider 16 is slidably fitted in the gap defined by the spacer 12, the wedge member 13, the adjusting member 14, and the bottom surface 11c of the concave groove 11 in the generatrix direction, that is, the direction oblique to the axis O. Has been inserted.

Here, the spacer 12 is a plate-like member which is disposed so as to extend over substantially the entire length of the portion of the concave groove 11 along the generatrix when mounted on the tool body 1. 11 is attached so as to be in close contact with the wall surface 11a and the bottom surface 11c, and has a serration of a cross-sectional wave shape on the inner side of the concave groove 11, that is, on the side surface facing the tool rotation direction T so as to extend along the generatrix direction. Groove 1
2a is formed. The wedge member 13 and the adjusting member 14 are slightly shorter than the spacer 12, and the tool body 1
The groove 11 is disposed so as to extend from the base end side of the bent portion in the state of being attached to the wedge member 13.
Is arranged on the outer peripheral side of the tool body 1 and the adjusting member 1
Numeral 4 is arranged on the bottom surface 11c side of the concave groove 11, and both are attached so as to be in close contact with the wall surface 11b. Further, the wedge member 13 and the adjustment member 14
The side surfaces 13a and 14a facing the inner side of the concave groove 11, ie, the rear side in the tool rotation direction T, are flush with each other and
The bottom surface 11c is inclined toward the side surface that comes into close contact with the wall surface 11b.

On the other hand, as shown in FIG. 1, the slider 16 is a prism-shaped member which bends in a substantially “C” shape in accordance with the bending of the concave groove 11. The cutting edge tip 5A is removably attached to a tip portion parallel to the axis O while being disposed along a portion along the axis O. At the base end of the slider 16, a serration groove 16 a having a corrugated cross section which is in close contact with the serration groove 16 of the spacer 12 is formed on one side surface facing the wall surface 11 a when attached to the tool body 1. The other side surface 16 b facing the wall surface 11 b opposite to the one side surface includes a wedge member 13 and an adjustment member 14.
In accordance with the inclination formed by the side surfaces 13a and 14a, the inclined surface is separated from the side surface on which the serration groove 16a is formed toward the bottom surface 11c side of the concave groove 11 in accordance with the inclination. However, as shown in FIG. 3, the slider 16 is provided with the serration groove 16a.
Of the wedge member 13 and the adjustment member 14, and the bottom surface 16a of the other side surface 16b.
c is slidably fitted in the gap with the bottom surface 11c of the groove 11 being in close contact with the bottom surface 11c.

The tool body 1 is provided with a chip discharge hole 17 communicating with the concave groove 11 and opening on the outer peripheral surface of the tool body 1 having a conical surface. This chip discharge hole 1
Reference numeral 7 denotes a circular cross section in the present embodiment.
a, 11b, which are open on the bottom surface 11c side,
Through the tool body 1 so that both ends extend through the tool body 1 so as to extend in both directions tangential to a circle centered on the axis O, that is, in a direction perpendicular to the cross section shown in FIG. It is formed in a through hole that opens on the outer peripheral surface. Accordingly, this allows the chip discharge hole 17 to move to the bottom surface 11c.
It is formed so as to be gradually separated from the axis O as going from the portion toward the opening side of the outer peripheral surface of the tool main body 1. Further, on one wall surface 11 a side of the concave groove 11 to which the spacer 12 is attached, the chip discharge hole 17 extends so as to penetrate the spacer 12. On the other hand, when the coupling member 9 is advanced, the coupling member 9 is positioned at a position facing the chip discharge hole 17, that is, at a position where the bottom surface 16 c of the slider 16 bends. The recess 18 having a substantially circular cross section is formed extending along the direction in which the chip discharge hole 17 is formed in a state in which the chip 18 is advanced.

However, in the cutting tool having such a configuration, chips entering the gap formed between the slider 16 and the concave groove 11 in a state where the coupling member 9 is retracted are removed by the concave groove 11. Chip discharge hole 1 communicating with
7 and is discharged to the outer peripheral side of the tool body 1 through the chip discharge hole 17, such a situation that such chips stay in this gap and hinder the sliding of the slider 16. Can be prevented. Here, the chip discharge hole 1 of the present embodiment
Numeral 7 is formed in a tangential direction of a circle centered on the rotation axis O of the tool main body 1, and is formed so as to be gradually separated from the axis O from a portion communicating with the concave groove 11 toward the outer peripheral side of the tool main body 1. Therefore, the swarf introduced into the swarf discharge hole 17 is forcibly sent to the outer peripheral side by the centrifugal force as the tool body 1 rotates during cutting, and is quickly discharged. You.

Further, in this embodiment, the chip discharge holes 17 are used.
Is formed in a through hole having a central portion communicating with the concave groove 11 and both ends opened to the outer peripheral surface of the tool body 1.
In the above, relative to one end of the tool body 1 on the tool rotation direction side, which is open to the outer peripheral surface, the other end that is open to the outer circumferential surface on the tool rotation direction rear side through a central portion communicating with the concave groove 11. Is formed, and the chips introduced into the chip discharge holes 17 are forcibly sent out of the tool body 1 by the air flow. In addition, due to this air flow, the gap between the groove 11 and the slider 16 is in a negative pressure state toward the chip discharge hole 17, so that the chips entering the gap are forcibly sucked. As a result, it is introduced into the chip discharge hole 17. Therefore, according to the present embodiment, it is possible to reliably prevent the swarf from staying in the gap, and to promptly discharge the swarf.

Further, in the present embodiment, the concave groove 11 is formed so as to extend parallel to the axis O at the tip end side of the tool body 1 and then bend toward the outer peripheral side to extend in the generatrix direction.
On the other hand, the chip discharge hole 17 is formed so as to communicate with a portion where the concave groove 11 is bent. That is, with respect to the gap defined between the concave groove 11 and the slider 16 when the coupling member 9 is retracted,
The swarf discharge hole 17 communicates with the groove 11 at a portion on the base end side of the gap where the groove 11 is bent.
However, since the chips are most likely to stay in such a portion, by forming the chip discharge holes 17 facing such a portion, according to the present embodiment, more efficient discharge of the chips can be achieved. It is possible to encourage.

Further, in the present embodiment, the groove 1
While a chip discharge hole 17 is formed in a portion where 1 is bent, a concave portion 18 is also formed in a portion where the slider 16 is bent in the slider 16, and the concave portion 18 moves the coupling member 9 forward. In this state, the chip discharge hole 17 extends in the direction in which the chip discharge hole 17 is formed.
It is formed so that it may communicate with. Therefore, even when the coupling member 9 is advanced and the slider 16 is slid, particularly during cutting by the cutting edge tip 5A, even if the gap defined on the distal end side of the tool body 1 becomes smaller. ,
Since the space at the portion flowing into the chip discharge hole 17 from the concave groove 11 is secured by the concave portion 18, according to the present embodiment, even when the coupling member 9 is advanced in this way, the slider 16 and the concave groove To prevent the chips from being caught between them and the chip discharge hole 1 reliably.
7 and discharged, whereby smooth cutting can be performed.

In this embodiment, the wall surface 11 of the concave groove 11 is
a, 11b and the slider 16
2, intervening members such as a wedge member 13 and an adjusting member 14 are detachably attached.
Since wear due to sliding or the like of 6 occurs on these interposed members, when such abrasion occurs, it is possible to easily recover the predetermined mounting accuracy and the like by replacing the interposed member. I'm playing. However, when such an interposed member is attached, the interposed member is disposed up to a position where the interposed member closes the opening of the chip discharge hole 17 facing the concave groove 11, such as the spacer 12 in the present embodiment. If so, by forming the chip discharge hole 17 so as to penetrate the interposition member as in the present embodiment, it is possible to prevent a situation where the discharge of the chip is hindered by the interposition member. be able to.

However, in this embodiment, the groove 1
The case where the interposition member is attached between the slider 1 and the slider 16 has been described. However, for example, like the conventional cutting tool shown in FIGS. Even in a cutting tool in which a slider is directly slidably mounted in a groove, the same effect as described above can be obtained by forming a chip discharge hole so as to communicate with the concave groove such as the T groove. Further, in this embodiment, one chip discharge hole 17 is formed so as to pass through the bent portion of the groove 11. However, for example, as shown by a broken line in FIG. A plurality of chip discharge holes may be formed in the tool body 1 by forming a second chip discharge hole 19 in the concave groove 11 or the like.

[0026]

As described above, according to the present invention, when the coupling member is retracted, chips enter the gap defined between the groove on the tip end side of the tool body and the slider. Even so, it can be introduced into the chip discharge hole communicating with the concave groove and can be quickly discharged from the outer periphery of the tool body. Therefore, it is possible to prevent such chips from staying in the groove, and the staying chips may hinder the sliding of the slider, or the chips may be caught between the slider and the groove. It is possible to prevent a situation in which the tool life is shortened due to inadvertent or abrasion being promoted, and to prolong a tool life while promoting a smooth cutting operation.

[Brief description of the drawings]

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

FIG. 2 is a front view of the embodiment shown in FIG.

FIG. 3 is a sectional view taken along line XX in FIG.

FIG. 4 is a side sectional view showing a conventional cutting tool.

FIG. 5 is a sectional view taken along the line ZZ in FIG.

FIG. 6 shows a conventional cutting edge tip 5A, 5B, 5 shown in FIG.
It is a figure which shows the rotation locus about the axis O of C.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tool main body 5A, 5B, 5C Cutting edge chip 9 Coupling member 10 Connecting pin 11 Concave groove 11a, 11b Wall surface of concave groove 11c Bottom of concave groove 11 12 Spacer (intervening member) 13 Wedge member (intervening member) 14 Adjusting member (intervening member) 16 Slider 17 Chip discharge hole 18 Recess of slider 16 19 Second chip discharge hole O Rotation axis of tool body 1

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-315810 (JP, A) JP-A-63-179106 (JP, U) US Patent 2896308 (US, A) US Patent 5048441 (US, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) B23B 51/10 B23B 51/08

Claims (6)

(57) [Claims] 1. A substantially conical tool body rotated about an axis is formed with a concave groove along a generatrix of the cone, and a slider provided with a cutting edge tip is provided in the concave groove. Along with being slidably mounted along the tool main body, the tool main body is rotatable integrally with the tool main body, and is movable forward and backward along the axis, and engages with the slider to engage the slider. In a cutting tool having a coupling member to be slid therein, at least one chip discharge hole is formed in the tool body and communicates with the concave groove and opens on the outer periphery of the tool body. A cutting tool characterized by the following. 2. The swarf discharge hole is formed so as to be gradually separated from the axis as it goes from the concave groove side to the opening side of the outer periphery of the tool main body. The described cutting tool. 3. The cutting tool according to claim 1, wherein each of the chip discharge holes is formed as a through hole that opens at an outer periphery of the tool body. 4. The groove is formed so as to extend in a direction parallel to the axis at a tip end portion of the tool body, and then bend outward to extend along the generatrix.
2. The method according to claim 1, wherein one of the chip discharge holes is formed so as to communicate with a portion where the concave groove is bent.
The cutting tool according to claim 3. 5. A recess extending in a direction in which the chip discharge hole is formed in the slider at least at a position facing the chip discharge hole when the coupling member is advanced. The cutting tool according to any one of claims 1 to 4, characterized in that: 6. An interposition member is detachably mounted between at least one of the opposed wall surfaces of the concave groove and the slider, and the chip discharge hole penetrates the interposition member. The cutting tool according to any one of claims 1 to 5, wherein the cutting tool is formed to perform cutting.