JP2826039B2 - 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. 5 and 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 edge tips 5 are provided on the outer periphery of the distal end portion of the tool main body 1, and these cutting edge tips 5 are used to machine the above-mentioned opening edge of the valve hole. However, only one cutting edge tip 5A is shown in FIG. 5, and the other two cutting edge tips 5B and 5C are not shown.

[0004] Of these cutting blade tips 5 ...
The two cutting blade tips 5B and 5C are directly fixed to the tool body 1, while the one cutting blade tip 5A is slidably mounted as described above. That is, along the direction of the conical generatrix formed by the tool body 1,
That is, a T groove 6 is formed along the direction oblique to the axis O as shown in FIG.
Are slidably fitted, and the cutting edge tip 5A is detachably fixed to the slider 7.
On the other hand, holes 1a and 2a are formed inside the tool body 1 and the adapter 2 along the axis O, respectively, and the slide shaft 8 and the coupling member 9 are inserted through these holes 1a and 2a. . 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 advance and retreat the slide shaft 8. By doing so, it is possible 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. A connection pin 10 is attached to the slider 7 and protrudes into the hole 1a through the hole 6a. The tip of the connection pin 10 is inserted into a slant hole 9b formed in the coupling member 9 so that Slider 7 and coupling member 9
And the coupling member 9 is moved forward and backward through the slide shaft 8, so that the slider 7 slides along the T groove 6 and the cutting edge tip 5A slides in a direction oblique to the axis O. It has been made to be.

In order to machine the above-described 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, the opening of the valve hole is chamfered by the two cutting blade tips 5B and 5C. 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 to slide the cutting tip 5A via the connecting pin 10 and the slider 7. As a result, the above-described tapered surface 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.

[0006]

By the way, in the cutting tool having the above-described structure, when the tapered surface is formed on the periphery of the opening of the valve hole as described above, the cutting load acting on the cutting edge tip 5A is reduced by the slider 7. Is received by the wall surface of the T-slot 6 of the tool main body 1 (particularly, the wall surface facing the tool rotation direction) through the tool, so that during such long-term use, the wall surface of the T-slot 6 is worn out by such a cutting load. Deformation occurs. Also, the wall surface will be worn by the slider 7 sliding in the T groove 6. Such abrasion may cause rattling of the slider 7, which may impair the processing accuracy of the cutting edge tip 5 </ b> A. Specifically, the slider 7 does not slide straight, but slides in a recessed portion at the portion where the wear has occurred, so that the tapered surface does not become an accurate conical surface but becomes a curved surface that expands like a drum. Would.

When such wear occurs in the cutting tool having the above-described configuration, the T-groove 6 is widened and corrected by polishing or the like to form a new wall surface, and the new T-groove 6 is formed. The slider 7 having a size and a shape corresponding to the above is re-manufactured to reuse the tool body 1 and the like. However, when such measures are taken,
Since the T-slot 6 must be modified and the slider 7 must be re-manufactured every time wear occurs, the operation is inevitably complicated, and the dimensions and shape of the slider 7 change each time it is re-manufactured. Therefore, the design must be redone, and there is a risk that reusing the tool body 1 may be uneconomical.

In the cutting tool having the above structure, the cutting edge tip 5A is positioned by the engagement between the T-slot 6 and the slider 7 inserted into the T-slot 6, so that the molding error of the T-slot 6 and the slider 7 is reduced. There is no room for adjustment, and in order to obtain desired processing accuracy, these T-grooves 6 and sliders 7 must also be formed with high precision, which is difficult.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and has a groove formed along a generatrix of a cone in a substantially conical tool body rotated about an axis. Is formed, a slider provided with a cutting edge tip is slidably mounted along the groove in the groove, and inside the tool body, it is rotatable integrally with the tool body. A cutting tool comprising a coupling member which is movable along the axis and engages the slider to slide the slider, wherein a pair of wall surfaces of the concave groove facing each other are provided. Between the slider and the slider, a pair of wedge-shaped spacers that press the slider by being pushed into the bottom surface side of the concave groove are detachably interposed, and the inner surfaces of the spacers facing each other are facing upward. In addition to the inclined surfaces that are separated toward the bottom surface side of the concave groove, both side surfaces of the slider facing these inner surfaces can be in close contact with the inner surface as inclined surfaces that are separated toward the bottom surface side of the concave groove. It is characterized by having.

[0010]

In the cutting tool having such a configuration, a wedge-shaped spacer is detachably interposed between the slider and the wall surface of the groove in which the slider slides, and the cutting tool acts on the slider from the cutting edge tip. Cutting load
Since it is received on the wall surface via these spacers, abrasion and deformation due to the cutting load occur on the spacers. In addition, wear due to sliding of the slider will also occur on the spacer,
Even if such abrasion or deformation occurs, it is extremely easy and economical to replace these members without reshaping the groove or remanufacturing the slider, and the machining accuracy by the cutting tool can be extremely easily and economically increased. Can be maintained.

In the cutting tool having the above structure, an adjusting member is provided between at least one of the spacers and the bottom surface of the groove so as to adjust the pressing amount of the slider by defining the pressing position of the spacer. The width and the like of the gap between the two spacers on which the slider slides can be adjusted according to the molding accuracy of the slider, and it is possible to easily cope with a case where a molding error occurs in the groove or the slider.

[0012]

FIG. 1 to FIG. 3 show an embodiment of the present invention. This embodiment has the same basic structure as the conventional cutting tool shown in FIG. Are assigned the same reference numerals to simplify the description. In these figures, the illustration of the adapter 2 and the slide shaft 8 is omitted. In this embodiment, instead of the T-slot 6 formed in the tool body 1 of the conventional cutting tool, a pair of opposed wall surfaces 11a and 11b parallel to each other and a bottom surface 11c orthogonal to these wall surfaces 11a and 11b are used. The defined groove 11 is formed along the direction of the generatrix of the tool body 1 having a substantially conical shape, and spacers 12 and 13 are provided with clamp screws 14 on the side of the wall surface 11a and the wall surface 11b in the groove 11. Are detachably attached. The tool rotation direction T of the spacers 12 and 13 is also different.
13 located on the front side of the groove and the bottom surface 1 of the groove 11
An adjusting member 15 is interposed between the adjusting member 15 and the first member 1c. The inner surfaces 12a, 13a, 1 of the spacer 12, the spacer 13, and the adjusting member 15 oppose each other.
A slider 16 is slidably fitted in the gap defined by 5a and the bottom surface 11c of the concave groove 11 so as to be slidable in the generatrix direction, that is, the direction oblique to the axis O.

The spacer 12 located on the rear side in the tool rotation direction T has a concave groove 11 when mounted on the tool body 1.
Is a plate-like member formed so as to extend over substantially the entire length of the groove 11 and is attached so as to be in close contact with the wall surface 11a and the bottom surface 11c of the groove 11.
, That is, the inner surface 12 facing the tool rotation direction T
“a” is an inclined surface that gradually moves toward the wall surface 11a from the outer peripheral side of the tool body 1 toward the bottom surface 11c of the concave groove 11. The spacer 13 and the adjusting member 15 are formed so as to extend over the entire length of the concave groove 11 when mounted on the tool body 1, similarly to the spacer 12, and the spacer 13 is provided on the outer peripheral side of the tool body 1. The adjusting member 15 is arranged on the bottom surface 11c side of the concave groove 11 and is attached so as to be in close contact with the wall surface 11b. And these spacers 1
3 and the inner surfaces 13a, 15a facing the inside of the concave groove 11 of the adjusting member 15, ie, the rear side in the tool rotation direction T.
Are inclined surfaces which are flush with each other and gradually toward the wall surface 11b as going toward the bottom surface 11c of the concave groove 11.
Accordingly, the inner surface 12a of the spacer 12 and the inner surfaces 13a, 15a of the spacer 13 and the adjusting member 15 are formed.
Means that the inner surfaces 12a, 13a, and 15 are gradually separated from each other toward the bottom surface 11c of the groove 11.
The gap defined by a and the bottom surface 11c has a dovetail shape.

On the other hand, the slider 16 is a prismatic member which is bent in a "U" shape as shown in FIG. 1 and has a base end disposed in the groove 11 and a tip end formed therein. The cutting blade tip 5A is detachably attached.
As shown in FIG. 3, the slider 16 has a base end formed in an isosceles trapezoidal cross section, that is, both side surfaces 16 a and 16 b of the base end are formed on the bottom surface 11 of the groove 11.
The side surfaces 16a and 16b are inclined so as to be separated from each other as going toward the side c.
It is set to be equal to the inclination of 3a, 15a. Thus, the slider 16 is provided on both sides 16a, 1
6b are brought into close contact with the inner side surfaces 12a, 13a, and 15a, respectively, and
1c, and is slidably fitted in the gap.

Also in this embodiment, three cutting blade tips 5 are attached to the tip of the tool body 1, and one of the cutting blade tips 5A is mounted on the slider 16 so as to be slidable. It has become. On the other hand, the other two cutting edge tips 5B and 5C are connected to the tool body 1 as shown in FIG.
Are arranged at regular intervals in the circumferential direction of the tool body 1 and are shifted from each other in the direction of the axis O of the tool body 1.
Here, FIG. 4 shows a rotation trajectory around the axis O drawn by these cutting edge tips 5A, 5B, 5C. As shown in FIG. 4, the two cutting edge tips 5B, 5C are shown.
Are arranged such that the cutting edge portions 5b and 5c used for the cutting intersect each other at an obtuse angle in the rotation locus. And the cutting edge tip 5A is
By sliding the slider 16, the cutting edge portion 5
The movement locus R drawn by a is located between the cutting edge portions 5b and 5c of the cutting edge tips 5B and 5C, and the two cutting edge portions 5b and 5c
5c is arranged to intersect at an obtuse angle.

Also in the cutting tool having such a configuration, the tool body 1 has a hole machining tool such as a gun reamer attached to the tip thereof, and is attached to a spindle end of a machine tool via an adapter or the like to perform cutting. Provided. That is, the tool body 1 is fed in the direction of the axis O while rotating the tool body 1 around the axis O in a state where the hole drilling tool is retracted to the base end side as shown in FIG. Then, chamfers C, C are formed in the openings of the holes. However, in FIG. 4, what is indicated by reference symbol S is a hard member such as a sintered alloy that is fitted to the periphery of the opening such as the valve hole as described above. Then, after the chamfers C and C are formed, the tool main body 1 is slightly retracted once while the tool main body 1 is being rotated, and then the coupling member 9 is advanced by protruding a slide shaft (not shown) so as to be connected. The slider 16 is slid in the generatrix direction via the pin 10 to move the cutting blade tip 5A along the movement locus R, thereby forming a tapered surface P at the opening of the hole. Thereafter, while the tool body 1 is still rotating, the hole drilling tool such as the gun reamer is advanced and inserted into the valve hole, and the valve hole itself is finished.

In the cutting tool having the above-described structure, the cutting load acting on the cutting edge tip 5A when forming the tapered surface P is transferred via the slider 16 to the spacer mainly located on the rear side in the tool rotation direction T. 12 will be accepted. Therefore, abrasion and deformation due to the cutting load occur in the spacer 12, and the concave groove 11, that is, the tool body 1 does not wear or deform. Wear caused by sliding the slider 16 also occurs on the spacer 12, the spacer 13, or the adjustment member 15, and the tool body 1
Will not be damaged. Since the spacer 12, the spacer 13, and the adjusting member 15 are all detachably attached to the tool body 1 by the clamp screws 14, these members are replaced when worn or deformed. This makes it possible to extremely easily recover the processing accuracy and the like. In addition, the member to be replaced may be of the same standard as the member before replacement, and it is extremely economical because there is no need to redesign the member every time wear occurs. This is the same when the slider 16 is replaced.

In the cutting tool having the above structure, the wedge-shaped spacers 12, 13 are pushed into the bottom surface 11c of the concave groove 11, and the inner surfaces 12a, 13a sandwich the side surfaces 16a, 16b of the slider 16 and press. To attach the slider 16 and the cutting blade tip 5A
Of the spacer 13
In this embodiment, the pressing amount of the slider 16 can be easily adjusted by changing the thickness of the adjusting member 15 interposed between the spacer 13 and the bottom surface 11c of the concave groove 11. That is, by replacing the adjusting member 15 with a member having a different thickness, the position where the spacer 13 is pushed into the concave groove 11 also changes, and the position of the inclined inner side surface 13a that presses the slider 16 is also the same. It changes while maintaining the inclination. Therefore, according to the present embodiment, for example, the spacers 12 and 13 and the slider 16
In the spacers 12, 13
Even if the width of the gap between the inner side surfaces 12a and 13a does not exactly match the width of both side surfaces 16a and 16b of the slider 16, the slider 16 may be loose and the adjusting member 15 may be replaced. This makes it possible to easily cope with this, secure the mounting accuracy of the slider 16, and allow the slider 16 to slide smoothly.

[0019]

As described above, according to the present invention, the cutting load acting on the cutting edge tip via the slider and the abrasion or deformation due to the sliding of the slider can be prevented by the interposition between the slider and the wall surface of the groove. Therefore, in such a case, by exchanging these members, it is possible to easily recover the mounting accuracy and the positional accuracy of the slider and maintain the processing accuracy. The member is economical because the standard does not change every time it is replaced. In addition, by interposing an adjusting member between the spacer and the bottom surface of the groove, the width of the portion where the slider slides can be easily adjusted, and there is a molding error in the groove or the slider. Can easily respond to this.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first 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 of the embodiment shown in FIG.

FIG. 4 shows the cutting edge tips 5A, 5B, 5 of the embodiment shown in FIG.
It is a rotation locus about the axis O of C.

FIG. 5 is a sectional view showing a conventional cutting tool.

FIG. 6 is a sectional view of the conventional example shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tool main body 5A, 5B, 5C Cutting edge chip 8 Slide shaft 9 Coupling member 10 Connecting pin 11 Concave groove 11a, 11b Wall surface of concavity groove 11c Bottom surface of concavity groove 12,13 Spacer 12a, 13a Spacer 12,13 Inner surface 15 Adjusting member 16 Slider 16a, 16b Side of slider 16

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shoji Takiguchi 1511 Furamaki, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Inside the Tsukuba Works, Mitsubishi Materials Corporation (72) Inventor Akira Venus 1511 Furimagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture (56) References JP-A-4-360711 (JP, A) U.S. Patent 2,896,308 (US, A) U.S. Patent 5,048,481 (US, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B23B 51/08 B23B 51/10

Claims (2)

(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. A cutting tool comprising a coupling member to be slid therein, wherein the slider is inserted between a pair of opposed wall surfaces of the concave groove and the slider by being pushed into a bottom surface side of the concave groove. A pair of wedge-shaped spacers that press against each other are detachably interposed, and the inner surfaces of these spacers facing each other are inclined surfaces that are separated from each other toward the bottom side of the concave groove, Both sides of the slider that faces the inner surface of these also, cutting tool, characterized in that an inclined surface that spaced apart and is capable close contact with the inner side surface toward the bottom side of the groove. 2. An adjusting member is provided between at least one of the pair of spacers and a bottom surface of the concave groove to regulate a pressing position of the slider by defining a pressing position of the spacer. The cutting tool according to claim 1, wherein: