JP2000210802A - Cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent trembling by cutting load acting to a cut blade while making the protruded amount of the cut blade adjustable in a cutting tool to which a slider equipped with a cut blade tip along a bus bar of a cone is attached so that it can slide on a tool major body of about conical shape to be turned around an axial line. SOLUTION: A cut blade tip 5A is attached on a head part 8b at the tip of a cartridge 8 with a shank part 8c formed at the rear end side. The shank part 8c is inserted into an attaching hole 7a formed on a slider 7 and then the cartridge 8 is attached on the slider 7 so that it can appear and disappear along an axial direction O. An adjusting screw 22 as a supporting member to support the head part 8b is attached on the rear side of rotational direction T of the tool to the attaching hole 7a. The head part 8b is interposed between a surface 8e facing to the rear end side of the head part 8b and the tip surface 7b of the slider 7 facing to the surface 8e.

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 such a cutting tool, the present inventors have proposed a cutting tool as shown in FIGS. 4 to 8 in, for example, Japanese Patent Application Laid-Open No. 6-304804.
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 is mounted on the tip of the tool main body 1 along the axis O. A boring tool (not shown) such as a gun reamer is fitted into the bush 3 and the tool is The main body 1 can be moved forward and backward. Furthermore, three cutting edge tips 5A,
5B and 5C are provided.
Out of A, 5B and 5C, two cutting edge tips 5B and 5C are directly fixed to the tool body 1 as shown in FIG. 7, while the remaining one cutting edge tip 5A is formed by the tool body 1. It is slidably mounted along the generatrix direction of the cone.

[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.
A concave groove 6 is formed as shown in FIGS.
A slider 7 is slidably mounted along the groove 6 in the groove 6, and the cutting edge tip 5A is detachably attached to the slider 7 as shown in FIG. . Here, a mounting hole 7a is formed at the distal end of the slider 7 in parallel with the axis O, and a cartridge 8 having a head 8b having a tip mounting seat 8a at the distal end is formed in the mounting hole 7a. The shaft-shaped shank 8c on the rear end side is fitted and inserted.
After being mounted on the chip mounting seat 8a by a clamp piece 8d, the shank portion 8c of the cartridge 8 is clamped by a clamp screw 9 to be mounted on the slider 7 via the cartridge 8. Reference numeral 10 in the drawing denotes an adjusting screw for adjusting the amount of protrusion of the cutting edge 5a in the direction of the axis O. Also, the groove 6
A spacer 11 and a wedge member 12 are detachably mounted on the wall surfaces 6a and 6b side of the slider 7 by clamp bolts 13, respectively, between the slider 7 and the spacer 11 and the slider 7 are not shown. The serration grooves allow engagement with each other.

Further, mounting holes 1a and 2a are respectively formed along the axis O inside the tool body 1 and the adapter 2, and the slide shaft 1 is formed in these holes 1a and 2a.
4 and a coupling member 15 are inserted therethrough. The coupling member 15 is fitted into the mounting hole 1a via a key 15a so as to be integrally rotatable with the tool body 1 around the axis O, and the slide shaft 14 is provided. Is made to reciprocate in the direction of the axis O in the mounting hole 1a. 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 16 protruding into the mounting hole 1a through the through hole 6c. The slider 7 is connected to the coupling member 15 by the tip of the connecting pin 16 being inserted into the oblique hole 15 b of the coupling member 15, and the coupling member 15 is
, 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 machine the above-described valve hole with the cutting tool having such a configuration, a 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 edge tips 5B, 5C fixed are chamfered C, C at the opening of the hole as shown in FIG. To form FIG. 8 shows the rotation trajectory of the cutting edge tips 5A, 5B, 5C around the axis O. The symbol S in the figure indicates a firing fit fitted around the opening such as a valve hole. It is a hard member such as a bonding metal. 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 14 is protruded so that the coupling member 15 is advanced. As described above, the slider 7 is slid via the connecting pin 16 to move the cutting edge tip 5A along the movement locus R to form the tapered surface P at the opening of the hole. After a while, the tool body 1
While rotating, the hole drilling tool is advanced by the shaft 4 and inserted into the valve hole, and the valve hole itself is finished.

[0006]

In the cutting tool constructed as described above, the cartridge 8 has a configuration in which the conical tip of the adjusting screw 10 comes into contact with the inclined surface of the rear end of the shank 8c. The protrusion of the cutting blade 5a is adjusted in accordance with the amount of screwing of the adjusting screw 10, and then the slider 7 is clamped by the clamp screw 9 to be adjusted.
It is fixed to. Therefore, unless the protrusion amount of the cutting blade 5a is set to be minimum, that is, unless the head portion 8b of the cartridge 8 is in close contact with the distal end surface 7b of the slider 7, the cartridge 8 is not shown in FIG.
The surface 8e facing the rear end side of the head portion 8b is separated from the front end surface 7b of the slider 7 as shown in FIG. 7A, and the shank portion 8c is attached to the slider 7 with the shank portion 8c slightly protruding from the front end surface 7b of the slider 7. Can be

However, as described above, the cartridge 8
In the state where the shank portion 8c is protruded from the tip end surface 7b of the slider 7 and the head portion 8b is in a so-called overhang state, when the cutting is performed by the cutting edge 5a, the cutting operation on the cutting edge 5a is performed. Depending on the load
The constricted shank 8c deflects in the direction in which a cutting load acts on the cutting edge 5a, that is, in the rearward direction in the tool rotation direction T, causing chattering vibration in the cartridge 8, thereby significantly impairing cutting accuracy or cutting. There is a problem that the life of the blade 5a is shortened. On the other hand, in order to prevent the occurrence of such chatter vibration, for example, the surface 8e of the head portion 8b of the cartridge 8 facing the rear end side is adjusted to the slider 7 so that the amount of protrusion of the cutting blade 5a is minimized as described above. When the cutting edge tip 5A is directly attached to the front end of the slider 7 without the cartridge 8 as shown in FIG. 9 or without being provided with the cartridge 8 as shown in FIG. The protrusion amount cannot be adjusted, and especially in the latter case, if the tip mounting seat of the slider 7 is damaged, the entire slider 7 must be replaced.

The present invention has been made under such a background, and in a cutting tool having the above-described configuration,
An object of the present invention is to provide a cutting tool capable of adjusting the amount of protrusion of a cutting blade attached to a slider, while preventing chatter vibration and the like due to a load acting on the cutting blade during cutting.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems and achieve such an object, the present invention provides a substantially conical tool body rotated about an axis along a generatrix of the cone. And a slider provided with a cutting edge chip is slidably mounted along the groove in the groove. The cartridge is mounted on the head portion at the end of the cartridge having the shank portion formed thereon, and the cartridge is inserted into the mounting hole formed in the slider so that the cartridge can be protruded and retracted in the axial direction. At the same time, the head portion is supported between the surface facing the rear end side of the head portion and the front end surface of the slider facing the surface, on the rear side in the rotation direction of the tool body with respect to the mounting hole. Support member Characterized in that it is interposed.

Therefore, in the cutting tool thus configured, the shank portion of the cartridge on which the cutting edge tip is mounted is inserted into the mounting hole of the slider in the same manner as the conventional cutting tool, and the cartridge is moved in the axial direction of the tool body. Since it is attached to the slider so that it can come and go, it is possible to adjust the amount of protrusion of the cutting blade. On the other hand, the support member interposed between the surface of the tip of the cartridge on which the cutting edge tip is mounted and facing the rear end side of the head and the tip of the slider causes the head to exert a cutting load. Therefore, even if the head portion is in an overhang state, it is possible to prevent occurrence of chatter vibration during cutting due to bending of the shank portion.

Here, as the support member, for example, a spacer having a thickness corresponding to the amount of protrusion of the cutting blade is interposed between the surface facing the rear end side of the head portion of the cartridge and the front end surface of the slider. However, in order to more precisely adjust the amount of protrusion and surely support the head portion, the supporting member may include a surface facing the rear end side of the head portion and a tip of the slider. It is desirable to employ a screw member that is screwed into one of the surfaces and protrudes from this one surface, and contacts the other surface to support the head portion. In particular, when such a configuration is adopted, the screw member is rotated by an operation from the distal end side of the cartridge so that the amount of protrusion from the one surface can be adjusted. Thus, the amount of protrusion of the cutting blade can be easily adjusted.

[0012]

FIG. 1 to FIG. 3 show an embodiment of the present invention. However, this embodiment is the same as the conventional cutting tool shown in FIGS. 4 to 8 except for the mounting structure of the cartridge 8 at the distal end of the slider 7. Are denoted by the same reference numerals, and description of portions not shown is omitted.

That is, in the present embodiment, a through hole 21 is formed in the head portion 8b of the cartridge 8 so as to be parallel to the axis O of the tool main body 1 from the front end surface to the surface 8e facing the rear end side. A female screw portion 21a is formed in the inner peripheral portion on the rear end side of the through hole 21, and the female screw portion 21a is provided with a support member (screw member) in the present embodiment.
Adjustment screw 22 is screwed in, and the rear end 22a
Projecting from a surface 8e facing the rear end of the head portion 8b, is brought into contact with the front end surface 7b of the slider 7. here,
The through hole 21 is located on the opposite side of the shank 8c of the cartridge 8 from the side where the rake face 23 of the cutting edge tip 5A mounted on the head 8b faces, that is, on the rear side in the rotation direction T of the tool body 1. It is arranged to be located at.
An engagement portion 22b such as a hexagon wrench hole for engaging with a work tool such as a hexagon wrench is formed at the tip of the adjustment screw 22. The engaging portion 2 is inserted into the through hole 21 and
2b, the adjusting screw 22 can be rotated by the operation from the front end side, and the head portion 8b
Rear end 22 of the adjusting screw 22 from the surface 8e facing the rear end
The protrusion amount of a is adjustable.

In this embodiment, the cutting edge tip 5A is a positive tip formed of a hard material such as cemented carbide into a substantially regular triangular plate shape, like the other cutting edge tips 5B and 5C (not shown). One of the equilateral triangular faces is directed to the tool rotation direction T as the rake face 23, and the cutting edge 5a formed at the corner of the rake face 23 is protruded toward the tool tip to form the head part 8b. And the clamp piece 8d is seated on the set chip mounting seat 8a.
The rake face 23 is pressed and fixed. However, instead of such a clamp-on type mounting means by the clamp piece 8d, for example, a mounting hole penetrating from the rake face 23 is formed in the cutting edge chip 5A,
The clamp screw inserted into this mounting hole is inserted into the chip mounting seat 8a.
A so-called screw-on type mounting means for fixing the cutting blade tip 5A by screwing it into the screw hole formed in the above-mentioned may be adopted.

In this embodiment, the cartridge 8
The shank portion 8c is formed in a substantially columnar shape, and a flat surface 24 is formed on a side portion facing the tool outer peripheral side,
The mounting hole 7a formed in the slider 7 has a stepped circular shape into which the shank portion 8c can be fitted, and is arranged so that its center line L is parallel to the axis O of the tool main body 1. Further, a tip of the slider 7 is provided with this mounting hole 7.
A screw hole 25 is formed from the outer peripheral side of the tool so as to be orthogonal to a, and a clamp screw 26 is screwed into the screw hole 25. The flat tip end of the clamp screw 26 is connected to the flat surface of the shank 8c. The cartridge 8 is fixed to the tip of the slider 7 by abutting the surface 24 and pressing the shank portion 8c toward the inner periphery of the tool. Further, the surface 8e facing the rear end side of the head portion 8b of the cartridge 8, the front end surface 7b of the slider 7, and the rear end surface 22c of the adjusting screw 22 abutting on the front end surface 7b are all the center line L. Is formed on a flat surface perpendicular to.

In the cutting tool thus configured, the distance from the cutting edge 5a of the cutting edge tip 5A to the rear end face 22c of the adjusting screw 22 in the direction of the center line L is the cutting distance from the tip end face 7b of the slider 7. The adjustment screw 22 is rotated as described above to adjust the amount of protrusion from the surface 8e facing the rear end side of the head portion 8b so as to correspond to the amount of protrusion of the blade 5a,
Thereafter, the rear end surface 22c of the adjustment screw 22 is brought into contact with the front end surface 7b of the slider 7, and then the cartridge 8 is fixed by the clamp screw 26. Therefore, in the cutting tool in which the cartridge 8 is fixed as described above, the load acting on the cutting blade 5a at the time of cutting causes the leading end surface 7
Even if the shank portion 8c of the cartridge 8 protruding from the b is bent backward in the tool rotation direction T, the surface 8e facing the rear end side of the head portion 8b is located behind the shank portion 8c in the tool rotation direction T. A rear end portion 22a of an adjustment screw 22 as a support member protruding from the head portion 8b is interposed between the front end surface 7b of the slider 7 and the rear end surface 22c of the adjustment screw 22. Since the head portion 8b is supported by contact with the cartridge 7b, the rigidity of mounting the cartridge 8 can be improved and the shank portion 8c can be prevented from being bent.

For this reason, according to the cutting tool having the above configuration,
To adjust the amount of protrusion of the cutting blade 5a, the cartridge 8
Even if the shank portion 8c is protruded from the tip end surface 7b of the slider 7 and the head portion 8b is overhanging, the cutting blade is bent by the bending of the shank portion 8c at the time of cutting as described above. Chatter vibration can be prevented from occurring in the tip 5A. Accordingly, it is possible to prevent the machining accuracy of the cutting tool from being impaired by the chatter vibration or to shorten the life of the cutting edge 5a by promoting the wear of the cutting edge 5a, and to provide a high-precision over a long period of time. Processing can be promoted, and even if the chip mounting seat 8a of the head portion 8b is damaged, only the cartridge 8 needs to be replaced, which is economical.

In the present embodiment, the surface 8e of the cartridge 8 facing the rear end of the head 8b is
The supporting member interposed between the front surface 7b of the
e, through-hole 2 formed in head portion 8b so as to open to
An adjusting screw 22 which is a screw member screwed into the female screw portion 21a of the first cutting portion 5a. As described above, the amount of protrusion of the rear end portion 22a of the adjusting screw 22 from the surface 8e is adjusted to thereby adjust the cutting edge 5a. Although the protrusion amount is adjustable,
Such a configuration is not adopted. For example, a spacer or the like having a thickness corresponding to the amount of protrusion of the cutting blade 5a is used as a supporting member between a surface 8e facing the rear end side of the head portion 8b and the distal end surface 7b of the slider 7. By interposing, it is possible to support the head portion 8b and adjust the amount of protrusion of the cutting blade 5a.

However, when such a configuration is adopted, spacers having a plurality of thicknesses corresponding to the protruding amounts of the cutting blades 5a must be prepared in advance, and the adjustment work becomes complicated. If the spacer is not held between the surface 8e facing the rear end side of the head portion 8b and the tip end surface 7b of the slider 7 without falling off even during cutting, the head portion 8b is surely supported. The occurrence of chatter vibration cannot be prevented. Therefore, as the support member, like the adjusting screw 22 of the present embodiment, the head 8
b is screwed into one of the surface 8e facing the rear end side and the front end surface 7b of the slider 7 (the surface 8e facing the rear end side of the head portion 8b in the present embodiment). It is desirable that the screw member supports the head portion 8b by projecting and abutting on the other surface (the end surface 7b of the slider 7 in the present embodiment). By adjusting the distance, the protrusion amount of the cutting blade 5a can be easily adjusted steplessly, and the head 8b of the cartridge 8 can be reliably supported.

In the present embodiment, as described above, the support member is the adjusting screw 22 as a screw member screwed into the surface 8e facing the rear end of the head portion 8b, and the rear end 22a is the head screw 8b. The rear end surface 22c projects from the surface 8e facing the rear end side of the portion 8b so that the rear end surface 22c abuts on the front end surface 7b of the slider 7. On the contrary, the adjusting screw is screwed into the front end surface 7b of the slider 7. The tip of the adjusting screw is brought into contact with a surface 8e facing the rear end of the head 8b, and the head 8b
It is also possible to configure to support. However, when such a configuration is adopted, the operation of rotating the adjusting screw to adjust the screwing amount is performed by the surface 8e facing the rear end side of the head portion 8b of the cartridge 8 from the tool outer peripheral side.
And the front end face 7b of the slider 7 or the cartridge 8 must be removed and the screwed amount adjusted each time, and then the cartridge 8 must be reattached. If it is small, operation may not be possible, or it may be difficult to finely adjust the amount of protrusion of the cutting blade 5a.

Therefore, in order to avoid such inconvenience, the adjusting screw 22 is screwed into the male screw portion 21a of the through hole 21 formed in the head portion 8b of the cartridge 8 as in this embodiment. It is preferable that the cartridge 8 be rotatable by an operation from the front end side of the cartridge 8, for example, by being rotatable by a work tool inserted through the through hole 21. In this embodiment, as described above, the support of the head portion 8b of the cartridge 8 and the adjustment of the protrusion amount of the cutting blade 5a are simultaneously performed by the adjustment screw 22, but, for example, the conventional configuration shown in FIG. Similarly to the cutting tool described above, an adjusting screw 10 is screwed into the slider 7 so that a conical tip protrudes from the inner periphery of the mounting hole 7a of the slider 7, and the shank of the cartridge 8 is inserted into the tip of the adjusting screw 10. The protrusion of the cutting blade 5a may be adjusted by abutting the inclined surface at the rear end of the cutting edge 8c, and the adjusting screw 22 may be configured to only support the head portion 8b.

[0022]

As described above, according to the present invention,
The head portion is supported between a surface facing the rear end side of the head portion of the cartridge which is mounted by inserting the shank portion on the rear end side into the mounting hole of the slider, and a front end surface of the slider opposed to this surface. The support member is interposed on the rear side in the rotation direction of the tool main body with respect to the mounting hole, whereby the mounting rigidity of the cartridge can be improved and the shank portion can be prevented from being bent during cutting. Therefore, while the cartridge can be protruded and retracted from the slider so that the protrusion amount of the cutting blade can be adjusted, it is possible to prevent chattering vibration and the like from being generated by a load acting at the time of cutting, thereby improving the cutting accuracy and improving the cutting blade life. Can be promoted.

[Brief description of the drawings]

FIG. 1 shows a cartridge 8 according to an embodiment of the present invention.
3 is an enlarged plan view showing the periphery of FIG.

FIG. 2 is an enlarged side view as viewed in the direction of arrow W in FIG. 1; (However, the clamp piece 8d is not shown.)

FIG. 3 is an enlarged front view of the cartridge 8 shown in FIG. (However, the clamp piece 8d is not shown.)

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

FIG. 5 is a front view of the conventional cutting tool shown in FIG. 4 as viewed from the tool tip side.

FIG. 6 is an enlarged sectional view of YOY in FIG. 5;

FIG. 7 is an enlarged sectional view of ZOZ in FIG. 5;

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

FIG. 9 shows another conventional cutting tool, Y in FIG.
It is an expanded sectional view equivalent to an OY sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tool main body 5A, 5B, 5C Cutting edge 5a Cutting edge of cutting edge 5A 6 Groove 7 Slider 7a Mounting hole of slider 7 7b Tip surface of slider 7 8 Cartridge 8b Head 8c Shank 8e After head 8b Surface facing the end side 22 Adjusting screw (support member, screw member) O Rotation axis of tool body 1 T Rotation direction of tool body 1

Claims (3)

[Claims] 1. A substantially conical tool body rotated about an axis is formed with a concave groove along a generating line of the cone, and a slider provided with a cutting edge tip is provided in the concave groove. A cutting tool that is slidably mounted along the cutting edge, wherein the cutting edge tip is mounted on a head portion at a tip end of a cartridge having a shank portion formed on a rear end side, and the cartridge has A shank portion is inserted into a mounting hole formed in the slider and attached to the slider so as to be able to protrude and retract in the axial direction, and a surface facing the rear end side of the head portion and a surface of the slider facing the surface. A cutting tool, wherein a support member for supporting the head portion is interposed between the tip end surface and a rotation direction rear side of the tool main body with respect to the mounting hole. 2. The support member is screwed into one of a surface facing a rear end of the head portion and a distal end surface of the slider, protrudes from the one surface, and contacts the other surface. The cutting tool according to claim 1, wherein the cutting tool is a screw member that supports the head portion. 3. The apparatus according to claim 2, wherein the screw member is rotated by an operation from the front end side of the cartridge, so that the amount of protrusion from the one surface is adjustable. The described cutting tool.