JPH1080812A - Cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress backlash of a slider in a cutting tool where a slider is slidably loaded in a recessed groove formed in the conical tool body to allow a cutting edge-tip to slide. SOLUTION: A spacer 8 provided with a serration groove 8a is removably interposed between one wall face 6a of a recessed groove 6 and a slider 7. A serration groove 7a engaging the serration groove 8a is formed on one side face of the slider 7 abutting on the spacer 8, while a V-shaped projected part 21 projected out with respect to one side face of the slider, is formed on the other side face of the slider 7. A pair of wedge members 22, 22 respectively closely contacting a pair of slopes 21a, 21a of the projected part 21 formed into a V-shape, are interposed between the other side face of the slider and the other wall face 6b of the recessed groove 6 so that they can be moved near and apart by a screw member 23.

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 As a cutting tool of this kind, the inventors of the present invention disclosed in Japanese Patent Application Laid-Open No. 7-241710, FIG.
Or the one shown in FIG. 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), and is rotated around its axis O for cutting. A bush 3 extends along the axis O at the tip of the tool body 1.
A hole machining tool (not shown) such as a gun reamer is fitted into the bush 3, and the bush 3 can be moved forward and backward with respect to the tool body 1 by the shaft 4. Further, three cutting edge tips 5A, 5B, 5
C are provided, and these cutting edge tips 5A, 5B,
Of the 5C, two cutting edge tips 5B and 5C are the tool body 1
And the other one of the cutting edge tips 5A
Are slidably mounted along the generatrix direction of the cone formed by the tool body 1.

[0003] That is, the tool body 1 is provided along the direction of its conical generating line, that is, in the direction oblique to the axis O.
As shown in FIG. 2, a concave groove 6 is formed.
A slider 7 is slidably mounted along the concave groove 6, and the cutting edge tip 5A is detachably fixed to the slider 7. Here, this groove 6
Is defined by a pair of opposing wall surfaces 6a, 6b parallel to each other and a bottom surface 6c orthogonal to the wall surfaces 6a, 6b. A spacer 8 is provided on the side of the wall surface 6a facing the side, and a wedge member 9 is provided on the side of the wall surface 6b facing the rear side in the tool rotation direction T.
Are detachably attached by clamp bolts 10, 11, respectively. The slider 7 is interposed between the spacer 8 and the wedge member 9.

The spacer 8 is a plate-like member formed so as to extend over substantially the entire length of the concave groove 6 when the spacer 8 is mounted on the tool body 1. The spacer 8 is a wall surface 6a and a bottom surface 6c of the concave groove 6. The spacer 8 is provided with a serration groove having a wave-shaped cross-section so as to extend along the generatrix direction on a side surface facing the inside of the concave groove 6 of the spacer 8, that is, a side surface facing the tool rotation direction T. 8a is formed as an engagement portion. Similarly to the spacer 8, the wedge member 9 also has a concave groove 6 when mounted on the tool body 1.
Is mounted so that the side surface 9a facing the tool rotation direction T side is in close contact with the wall surface 6b, and is inside the concave groove 6, that is, in the tool rotation direction T. The side surface 9b facing the rear side is an inclined surface toward the side surface 9a as it goes toward the bottom surface 6c of the concave groove 6.

As shown in FIG. 2, the slider 7 is a prismatic member which is bent in the shape of a letter "K". The slider 7 has a base end disposed in the groove 6 and a tip end formed with the cutout. The blade tip 5A is detachably attached. At the base end of the slider 7, a serration groove 8 a of a spacer 8 is provided on one side surface facing the wall surface 6 a side.
A serration groove 7a having a wavy cross section is formed as the engaged portion, while the other side surface 7b facing the opposite wall surface 6b is formed with a concave groove according to the inclination formed by the side surface 9b of the wedge member 9. 6 are inclined from the one side surface toward the bottom surface 6c. A disc spring 12 is loosely inserted into the clamp bolt 11 inserted through the wedge member 9 in a compressed state, and the disc spring 12 urges the wedge member 9 toward the bottom surface 6 c of the concave groove 6. As a result, the slider 7 is always pressed against the spacer 8 so that the serration grooves 7a, 8a are kept in a matched state.

On the other hand, mounting holes 1a and 2a are formed along the axis O inside the tool body 1 and the adapter 2, respectively.
And the coupling member 14 is inserted. The coupling member 14 is connected to the mounting hole 1 through a key 14a.
a, whereby the coupling member 1
Numeral 4 can rotate integrally with the tool body 1 about the axis O, and can advance and retreat in the mounting hole 1a by moving the slide shaft 13 forward and backward. Further, the concave groove 6 of the tool body 1 and the mounting hole 1a communicate with each other through a through hole 6d, while the slider 7 has a connecting pin 15 protruding into the mounting hole 1a through the through hole 6a. The slider 7 is connected to the coupling member 14 by the tip of the connection pin 15 being inserted into the oblique hole 14 b of the coupling member 14, and the slide shaft 13 is used as described above. , The slider 7 slides in the concave groove 6 to slide the cutting tip 5A in a direction oblique to the axis O.

In order to perform the above-described machining of the valve hole with the cutting tool having such a configuration, the hole machining tool is mounted on the bush 3 and pulled into the base end side of the tool body 1 by the shaft 4. The tool body 1 is fed in the direction of the axis O while rotating about the axis O. First, the two cutting blade tips 5B and 5C fixed are chamfered C and C in the opening of the hole as shown in FIG. To form When the chamfers C and C are formed in this manner, the tool body 1 is slightly retracted once while the tool body 1 is being rotated, and then the slide shaft 13 is protruded so that the coupling member 14 is advanced. As described above, the slider 7 is slid via the connecting pin 15 to move the cutting edge tip 5A along the movement locus R to form the tapered surface P at the opening of the hole. Then, with the tool body 1 still rotating,
The hole drilling tool is advanced by the shaft 4 and inserted into the valve hole, and the valve hole itself is finished.

FIG. 5 shows the cutting blade tips 5A and 5A.
FIG. 5 shows the rotation trajectory of the first and second cutting blades 5B and 5C around the axis O of B and 5C.
C is arranged so that the cutting edge portions 5b and 5c used for the cutting intersect each other at an obtuse angle in the rotation locus. On the other hand, the movement trajectory R along which the cutting edge portion 5a of the cutting edge tip 5A moves by sliding the slider 7 is located between the cutting edge portions 5b and 5c of the cutting edge tips 5B and 5C. , 5c so as to extend in a direction intersecting at an obtuse angle. Further, reference numeral S in the figure denotes a hard member such as a sintered alloy fitted to the periphery of the opening such as a valve hole.

However, in the cutting tool configured as described above, the cutting load acting on the cutting edge tip 5A is mainly received by the spacer 8 via the slider 7, and the wear caused by the sliding of the slider 7 Since the tool body 1 is mainly generated on the spacer 8 and the wedge member 9, the tool body 1 is not damaged by the cutting load or the sliding of the slider 7, and the spacer 8 is economical.
Since the wedge member 9 is replaceable, even if it is worn or deformed, it is possible to easily and quickly recover the processing accuracy. Further, in the above cutting tool, the wedge member 9 is urged toward the bottom surface 6 c of the concave groove 6 by the disc spring 12, so that the slider 7 is always moved to the spacer 8.
As a result, even if the serration grooves 7a, 8a of the spacer 8 and the slider 7 are slightly worn, the rattle of the slider 7 can be suppressed.

[0010]

However, in the above cutting tool, the wedge member 9 is urged toward the bottom surface 6c by the disc spring 12 as described above, so that the bottom surface 6c of the concave groove 6 is formed.
The side surface 9b of the wedge member 9 inclined toward the wall surface 6b toward the side presses the other side surface 7b of the slider 7 to press the slider 7 against the spacer 8, so that the slider 7 moves toward the spacer 8 side. It is inevitable that a pressing force toward the bottom surface 6c of the concave groove 6 acts together with the pressing force. And, by this latter pressing force,
The lower surface 7c of the slider 7 may be pressed against the bottom surface 6c of the concave groove 6 and both surfaces may be worn, and the serration grooves 7a and 8a engaging with each other also face the bottom surface 6c side of the serration groove 7a. Wear may be accelerated more unevenly than the serration groove 8a in contact with the portion facing the tool outer peripheral side (upward in FIG. 3) than the other portions.

The present invention has been made under such a background. In a cutting tool in which the above-mentioned cutting edge tip is slidable, the slider generates a pressing force toward the bottom surface side of the concave groove. Provided is a cutting tool which can prevent wear of the slider lower surface and the concave groove bottom surface and uneven wear of the serration groove (the engaging portion and the engaged portion), and can more reliably suppress rattling of the slider. It is intended to be.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to achieve the above object, the present invention provides a method for manufacturing a tool body comprising a pair of opposed wall surfaces of a concave groove extending in a generatrix direction.
A spacer having an engaging portion extending in the generatrix direction is removably interposed between one wall surface and the slider, and one side surface of the slider abutting on the spacer is provided with the engaging member. The other side of the slider has a V-shaped convex portion that is convex with respect to the one side surface or a V-shaped cross section that is depressed toward the one side surface. A pair of inclined surfaces each having a V-shaped inclined surface formed between the other side surface and the other wall surface of the concave groove. The wedge members are interposed so as to be detachable from each other. Accordingly, the slider is configured such that the pair of wedge members contact the pair of inclined surfaces formed on the other side surface of a pair of convex or concave portions having a V-shaped cross-section, and the inclined surfaces contact one of the concave grooves. Of the pressing force applied to the slider by the pair of wedge members,
The pressing force acting in the direction perpendicular to the bisector of the pair of inclined surfaces, that is, the pressing force in the direction perpendicular to the bottom surface of the concave groove is opposite to each other and is canceled out. Pressing force acting on the bottom surface side of the can be reduced.

Here, in order to make the pair of wedge members detachable from each other, for example, both wedge members may be screwed into both screw portions of a screw member provided with a screw portion that is twisted in opposite directions. At this time, the gap between the other side surface of the slider and the other wall surface of the concave groove is, when a convex portion having a V-shaped cross section is formed on the other side surface, the tool inner peripheral side (concave groove). When a concave portion is formed, the slope on the outer peripheral side of the tool (on the side opposite to the bottom surface of the concave groove) becomes gradually narrower, thereby connecting with the screw member. Since the movement of the wedge member in the radial direction of the tool is restricted, the wedge member and the slider do not rattle or fall off in the radial direction of the tool without providing a locking member or the like. . In addition, the pair of V-shaped inclined surfaces of the convex portions or the concave portions have a cross section whose inclination angle with respect to a line perpendicular to the bisector of the pair of inclined surfaces is in a range of 1 ° to 45 °. If the inclination angle is smaller than the above range, the pressing force on the one wall side of the slider with respect to the urging force between the two wedge members becomes smaller, so a larger urging force is required. On the other hand, if the inclination angle is larger than the above range, on the other hand, the depth of the concave portion formed in the slider to one side surface increases, and accordingly the width of the slider must be increased. I will have to.

[0014]

FIG. 1 shows an embodiment of the present invention. This embodiment is basically the same as the conventional cutting tool shown in FIGS. Therefore, the same parts are assigned the same reference numerals to simplify the description. That is, in the present embodiment, as shown in FIG. 1 which is a cross-sectional view orthogonal to the bottom surface 6 c of the concave groove 6, the slider 7 faces the tool rotation direction T rearward on the other side facing the tool rotation direction T. A convex portion 21 having a V-shaped cross section which is convex with respect to the side surface of the groove is formed between the other side surface and the other wall surface 6b of the concave groove 6 facing the rear side in the tool rotation direction T. A pair of wedge members 22, 22 are arranged side by side in the tool radial direction (vertical direction in FIG. 1), and these wedge members 22, 22 have screw portions 23a, 23a that are twisted in opposite directions at both ends. Each of the screw members 23 is screwed. A spacer 8 is interposed between a wall surface 6a of the concave groove 6 facing the tool rotation direction T and the one side surface of the slider 7, and is fixed by a clamp bolt 10, and the spacers 8 contact and face each other. The serration grooves 8a and 7a are formed as an engaging portion and an engaged portion on the side surface of the slider 7 and one side surface of the slider 7, respectively.
It is the same as the above-mentioned conventional cutting tool.

Here, the convex portion 21 is formed by a pair of inclined surfaces 21a, 21a, the other side surface of the slider 7 approaching and intersecting with each other in a direction away from the one side surface.
21a, the V-shaped bisectors formed by the cross sections of the inclined surfaces 21a, 21a are formed by the concave grooves 6 as described above.
The slider 7 is set so as to be parallel to the lower surface 7c of the slider 7 which is in close contact with the bottom surface 6c, and to pass through a position which is の of the thickness of the slider 7. Further, in this section, the inclined surfaces 21a, 21a are defined with respect to a straight line L perpendicular to the bisector, that is, a line orthogonal to the lower surface 7c of the slider 7.
Is set in the range of 1 ° to 45 ° in the present embodiment. Therefore, the intersection angle between the inclined surfaces 21a, 21a is set in the range of 178 ° to 90 ° in the present embodiment.

On the other hand, the wedge members 22, 22 are
And a columnar member having a trapezoidal cross section that is substantially symmetrical to each other, and includes a tool inner peripheral side (lower side in FIG. 1) between the slider 7 and the other wall surface 6b of the concave groove 6 and a tool outer peripheral side ( 1 (upper side in FIG. 1), and are arranged to extend over substantially the entire length of the concave groove 6 in a state of being mounted on the tool body 1 like the spacer 8. Further, the thickness of these wedge members 22, 22 (the straight line L
(Thickness in the direction) is set to be slightly smaller than １ ／ of the thickness of the slider 7.
Small gaps are defined between the wedge members 2 and 22 and between the wedge member 22 on the tool inner peripheral side and the bottom surface 6c of the concave groove 6 as shown in the figure. And these wedge members 2
One of the side surfaces 22a, 22a facing the slider 7 of the side surfaces of the wedge members 22, 22 is directed away from the other wedge member 22 side. The wedge member 22 on the tool outer peripheral side is separated from the other side surface 22b side of the wedge member 22 facing the other wall surface 6b side of the concave groove 6 toward the tool outer peripheral side as it goes to the circumferential side. The inclination angle is set to be equal to the above-mentioned inclination angle θ.

Further, these wedge members 22, 22 are provided with the other side surfaces 22b, 22b respectively.
Screw holes 22c, 22c are formed so as to be coaxial with the other wall surface 6b in close contact with the wedge member 2 as shown in FIG.
In the state in which 2, 22 are mounted, the twist direction is formed to be opposite. And these screw holes 2
The screw portions 23a, 23 of the screw member 23 are provided in 2c, 22c.
a are screwed into each other, and by rotating this screw member 23, both wedge members 22, 22 can be separated from each other, and by approaching both wedge members 22, 22, each wedge member 22 becomes The one side surface 22a is in close contact with the inclined surface 21a of the convex portion 21 of the slider 7 to press the slider 7 against the one wall surface 6a of the concave groove 6, and the other side surface 22b is connected to the other wall surface 6b of the concave groove 6. On the other hand, the slider 7 is pressed against the one wall surface 6a side of the concave groove 6 by the wedge members 22, 22, and the serration groove 8a of the spacer 8 is formed on the one side surface. Will surely be engaged.

However, in the cutting tool configured as described above, of the pressing force acting on the slider 7 from the wedge members 22, 22, the direction in which the slider 7 is pressed against the one wall surface 6 a of the concave groove 6 is selected. The component in the direction orthogonal to the component, that is, the component acting in the direction of the straight line L is
The two wedge members 22, 22 are equal in size and opposite in direction to each other, so that the two wedge members 22 are offset from each other, so that no force acts on the slider 7 to press the slider 7 against the bottom surface 6c of the concave groove 6. . For this reason, according to the cutting tool having the above-described configuration, it is needless to say that the serration grooves 7a and 8a are always reliably engaged by the pressing force on the one wall surface 6a side, thereby preventing the slider 7 from rattling. The slider 7 is pressed by the pressing force against the bottom surface 6c.
This prevents the wear between the lower surface 7c and the bottom surface 6c from being promoted and uneven wear between the serration grooves 7a and 8a, thereby preventing the slider 7 from rattling due to such wear. Accordingly, high-precision cutting can be achieved while extending the life of each member to promote maintenance-free cutting tools.

In this embodiment, the wedge member 2
2, 22 are screw holes 22 of these wedge members 22, 22, respectively.
The two wedge members 22, 22 are relatively simple in structure for separating and coming into contact with each other by a screw member 23 having screw portions 23a, 23a screwed to the c and 22c. When replacing the wedge members 7, the spacers 8, or the wedge members 22, 22, only the clamp bolts 10 for fixing the spacers 8 need to be removed, and the replacement work can be facilitated. Moreover, the slider 7 is engaged with the spacer 8 by the serration grooves 7a, 8a despite the fact that the slider 7, the spacer 8, and the wedge members 22, 22 are attached only by the clamp bolts 10 in this manner. The slider 7 and the wedge members 22 are formed on the inclined surface 2 on the tool inner peripheral side (the bottom surface 6 c side of the concave groove 6) of the convex portion 21 of the slider 7.
By gradually narrowing the distance between 1a and the other wall surface 6b of the concave groove 6 toward the outer peripheral side of the tool, the wedge member 22 on the inner peripheral side of the tool is locked on the outer peripheral side of the tool, and The wedge member 22 on the tool outer peripheral side is a screw member 23.
Since the slider 7 and the wedge members 22, 22 are rattled in the radial direction of the tool body 1 at the time of cutting or the like without being particularly provided with a locking member or the like, Stable cutting can be promoted without falling off from the concave groove 6.

Further, in the present embodiment, the inclination angle θ formed by the inclined surfaces 21a, 21a defining the convex portion 21 with respect to a straight line L orthogonal to the bisector is set in a range of 1 ° to 45 °. Accordingly, it is possible to prevent the protrusion 21 from being too deep on one side surface of the slider 7 and to increase the width of the slider 7 itself. 21a is too small, the wedge member 2 formed by the coil spring 23
For the biasing force of 2,22, the spacer 8 of the slider 7
It is possible to prevent the pressing force on the side from being reduced.

In this embodiment, a convex portion 21 having a V-shaped cross section is formed on the other side surface of the slider 7.
Side surface 2 of the convex portion 21 which is in close contact with the inclined surfaces 21a, 21a.
The slider 7 is pressed against the one wall surface 6a side of the concave groove 6 by bringing the wedge members 22, 22 having 2a, 22a closer to each other by the screw member 23, but conversely, the other of the slider is used. A wedge member having a V-shaped cross-section recessed toward one side and having a slanted side surface in close contact with a pair of inclined surfaces of the recess is formed on a side surface of the screw. The slider may be pressed against one wall side of the concave groove by separating the slider by a member or the like, and the engaging portion such as the serration groove and the engaged portion may be engaged with the spacer. The engaging portion and the engaged portion may be engaged with each other by, for example, a concave portion and a convex portion having a V-shaped cross section, in addition to the serration grooves 7a and 8a.

[0022]

As described above, according to the present invention,
A pair of wedge members urged in the direction away from each other,
By bringing the slider into close contact with a pair of inclined surfaces of a convex portion or a concave portion having a V-shaped cross section formed on the slider, the slider is pressed against the spacer side so that the engaging portion and the engaged portion are securely engaged with each other. In addition, it is possible to suppress the pressing force for pressing the slider against the bottom surface of the groove. Accordingly, wear of the lower surface of the slider and the bottom of the concave groove and uneven wear of the engaging portion and the engaged portion can be prevented, and the life of each member can be extended. It is possible to prevent rattling and promote high-precision cutting.

[Brief description of the drawings]

FIG. 1 shows one embodiment of the present invention, Z in FIG.
FIG. 3 is a sectional view corresponding to a Z section.

FIG. 2 is a sectional view showing a conventional cutting tool.

FIG. 3 is a front view of the cutting tool shown in FIG. 2;

4 is a ZZ sectional view of the cutting tool shown in FIG.

FIG. 5 shows cutting edge tips 5A and 5 of the cutting tool shown in FIG.
It is a figure which shows the rotation locus about the axis O of B and 5C.

[Explanation of symbols]

Reference Signs List 1 tool body 5A, 5B, 5C cutting edge tip 6 concave groove 6a one wall surface of concave groove 6 facing tool rotation direction T 6b other wall surface of concave groove 6 facing tool rotation direction T rear side 6c bottom surface of concave groove 6 Reference Signs List 7 slider 7a serration groove (engaged part) 8 spacer 8a serration groove (engagement part) 21 convex part 21a inclined surface of convex part 22 wedge member 22a one side surface of wedge member 22 facing rearward in tool rotation direction T 23 Screw member T Tool rotation direction L Straight line perpendicular to the bisector of the inclined surfaces 21a, 21a θ Angle of inclination of the inclined surface 21a with respect to the straight line L

Claims (3)

[Claims] 1. A substantially conical tool body rotated about an axis is formed with a concave groove along a generatrix direction of the cone, and a slider provided with a cutting edge tip is provided in the concave groove. A cutting tool slidably mounted along the groove, comprising a pair of opposed wall surfaces of the concave groove, between one of the wall surfaces and the slider, an engaging portion extending in the generatrix direction. The spacer is detachably interposed, and on one side of the slider that is brought into contact with the spacer, an engaged portion that engages with the engaging portion is formed, while the other side of the slider is formed. Is formed with a convex portion having a V-shaped cross section which is convex with respect to the one side surface or a concave portion having a V-shaped cross section which is concave with respect to the one side surface. Between the other wall surface of the A cutting tool a pair of wedge members having an inclined surface which is in close contact to the pair of inclined surfaces forming a V-shaped is characterized in that it is the disjunction capable interposed with each other. 2. The device according to claim 1, wherein the pair of wedge members are detachable from each other by being screwed into a screw member having a screw portion twisted in opposite directions. Cutting tools. 3. A pair of the V-shaped inclined surfaces of the convex portion or the concave portion has an inclination angle of 1 ° to 45 ° with respect to a line perpendicular to a bisector of the pair of inclined surfaces in a cross section thereof. 2. The method according to claim 1, wherein the setting is made such that
Or the cutting tool according to claim 2.