JP2001121320A - Cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To couple a coupling and a slider reliably in a cutting tool for valve hole machining, with simple means and without circumferential adjusting mechanisms in the tool body. SOLUTION: A tool body 1 generally in the shape of a truncated cone is mounted, in a groove 5 cut along a generating line, with a slider 6 with a cutting edge tip 4 so that it can slide along the generating line, and is further mounted, in an internal mounting bore 1a, with a coupling 13 rotatable integrally with the tool body 1 and movable back and force in the direction of the axis O thereof. The coupling 13 has a connecting hole 14 opening to a communicating hole 5e via which the groove 5 and mounting bore 1a communicate with each other. The slider 6 has a connecting pin 16 projected into mounting bore 1a via the communicating hole 5e and inserted in the connecting hole 14 for back- and-force motion. The connecting pin 16 is fitted in the connecting hole 14 for engagement along the generating line and for sliding motion along the circumference of the tool body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool particularly 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 have disclosed, for example, Japanese Patent No. 2779112 and Japanese Patent No. 280.
No. 4696, etc., a hole machining tool such as a gun reamer is provided at the tip of a substantially conical tool body rotated about an axis so as to be able to protrude and retract along the axis, and the vicinity of the hole machining tool at the tip of the tool body. A cutting edge tip is attached to each of the inner peripheral side and the outer peripheral side, and the cutting edge tip is also provided at a concave groove formed along the generatrix direction of the cone formed by the tool main body on the outer periphery of the tool main body. It has been proposed that a slider provided is mounted so as to be slidable in the generatrix direction. Here, a coupling is attached to a mounting hole formed inside the tool main body via a key extending parallel to the axis so as to be integrally rotatable with the tool main body and advance / retreat in the axial direction. A coupling hole is formed in the coupling in a direction orthogonal to the generatrix and crossing the axis. On the bottom surface of the groove, the coupling hole is opened to allow the attachment hole to communicate with the groove. A communication hole is formed.

[0003] Further, the slider is provided with a connecting pin that protrudes into the mounting hole from the communication hole on the bottom surface of the concave groove and is inserted into the connecting hole of the coupling so as to be freely retractable. By moving the slider in the axial direction, the connecting pin slides in the generatrix direction along the concave groove while the connecting pin protrudes and retracts from the connecting hole, so that the cutting edge tip at the tip is also moved in parallel with the generatrix. Can be Therefore, according to the cutting tool having such a configuration, while the inner periphery of the valve hole is machined by the hole machining tool, the rotation trajectory that the movement path of the cutting edge tip of the slider makes around the axis is a tool. By setting so as to connect between the rotation trajectories of the cutting edge tips on the inner and outer circumferences of the front end of the main body, the processing of the periphery of the opening of the valve hole by these cutting edge tips is exactly coaxial with the processing of the valve hole. Can be performed.

[0004]

By the way, in the cutting tool having such a structure, the slider attached to the concave groove on the outer periphery of the tool main body is connected to the connecting pin by the reciprocation of the coupling attached to the mounting hole inside the tool main body. In order to be able to slide reliably in the direction of the generatrix through the above, it is necessary to manufacture each of these tool bodies, sliders, couplings, and connecting pins with high molding precision, respectively. It is inevitable that a certain amount of molding error and variation in accuracy will occur when manufacturing. However, in this regard, in the above-mentioned conventional cutting tool, an adjusting member is inserted between the concave groove of the tool body and the slider together with a wedge member and a spacer, and both the slider and the connecting pin are provided between the slider and the connecting pin. It is proposed to provide a fine adjustment mechanism for finely adjusting the position in the generatrix direction.

[0005] However, the connecting pin and the coupling are formed by simply inserting and connecting the columnar connecting pin to the connecting hole which is a circular hole having a circular cross section formed in the conventional coupling. Therefore, even if the position of the connection pin and the connection hole in the generatrix direction can be adjusted by the fine adjustment mechanism, the connection error between the connection pin and the connection hole in the circumferential direction of the tool main body due to the molding error and variation in accuracy. If the position shifts, the coupling pin cannot be inserted into the coupling hole to connect the coupling and the slider. On the other hand, in addition to the fine adjustment mechanism for the position in the generatrix direction, an adjustment mechanism for finely adjusting the position in the circumferential direction is provided for the slider of a limited size attached to the concave groove formed in the tool body. It is extremely difficult to provide, and even if such an adjustment mechanism can be provided, it is inevitable that the adjustment work in these two directions becomes extremely complicated.

The present invention has been made in view of such circumstances, and in a cutting tool having the above-described configuration, there is no need to provide such a mechanism for adjusting the circumferential direction of the tool body, and simple means is used. Further, it is an object of the present invention to provide a cutting tool capable of connecting a coupling and a slider by reliably inserting a connecting pin into a connecting hole.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to achieve such an object, the present invention is directed to forming a tool body along a generating line of a tool body having a substantially truncated conical shape which is rotated around an axis. A slider having a cutting edge tip is slidably mounted in the generatrix direction in the recessed groove, and a mounting hole formed inside the tool body is rotatable integrally with the tool body and in the axial direction. A coupling hole is formed in the coupling so as to be able to advance and retreat, and a coupling hole is formed in the coupling so as to face a communication hole communicating the concave groove and the mounting hole. On the other hand, the slider is provided with the coupling hole from the communication hole. Providing a connecting pin that protrudes into the hole and is inserted into the connecting hole so as to be freely retractable,
The connection pin is fitted into the connection hole so as to be engageable in the generatrix direction and to be slidable in the circumferential direction of the tool body.

That is, in the cutting tool having the above-described configuration, the connecting pin slides the slider in the generatrix direction by being inserted into the connecting hole of the coupling. Since the slider is mounted in the concave groove, the slider is positioned at a predetermined position by the inner wall of the concave groove, the wedge member, and the spacer, so that the coupling pin and the coupling engage only in the generatrix direction. And it need not be engaged in the circumferential direction of the tool body. Therefore, if the connecting pin is slidable in the circumferential direction with respect to the connecting hole, even if the connecting pin, the spacer, and the coupling have a molding error or the like, the connecting pin or the connecting hole may be in the circumferential direction. Even if it is deviated from the predetermined position, the connection pin can be inserted into the connection hole at this deviated position (however, it is fitted only in the direction of the above-mentioned generatrix). Since the engagement between the pin and the coupling in the generatrix direction is not hindered, the slider can be reliably slid by the reciprocation of the coupling via the connecting pin.

In order to allow the connecting pin to be engaged with the connecting hole in the bus line direction and to be slidable in the circumferential direction of the tool body, the connecting hole must be connected to the bus line. It is desirable to form a long hole extending in the circumferential direction of the tool body with a width in which the connection pin can be inserted in the direction. However, even though the connecting pin is slidable in the circumferential direction of the tool body with respect to the connecting hole, this is because the connecting pin is fitted in the bus direction in the circumferential direction. In the assembled cutting tool, even if the slider is slid by moving the coupling forward and backward, the connecting pin does not move when the connecting pin moves in and out of the connecting hole. It merely slides in the direction of the center axis of the connecting pin, and does not move in the connecting hole in the circumferential direction of the tool body. Further, in order to more reliably engage the connection pin and the connection hole in the bus direction, the connection hole includes a pair of mutually parallel wall surfaces facing in the bus direction, and the connection pin includes It is desirable to form a pair of parallel side surfaces that can slide on these wall surfaces.

[0010]

FIG. 1 to FIG. 5 show an embodiment of the present invention. In the present embodiment, the tool main body 1 has a substantially multi-stepped truncated cone shape whose diameter gradually decreases as it goes toward the front end side (the left side in FIG. 1), and its rear end is located at the spindle end of a machine tool (not shown). Being attached,
It is rotated around its axis O in the tool rotation direction T shown in FIG. A bush 2 is attached to the tip of the tool main body 1 along the axis O. A shank of a hole machining tool (not shown) such as a gun reamer described above is inserted into the bush 2 and the tool main body 1 is inserted. By advancing the hole drilling tool while rotating each time, the above-described finishing of the inner periphery of the valve hole and the like can be performed. Reference numeral 3 in the drawing denotes a clamp mechanism for attaching the shank of the hole machining tool to a chuck spindle (not shown).

Further, on the outer periphery of the distal end portion of the tool body 1, there are provided three cutting edge chips 4 for processing the periphery of the opening of the valve hole. Two of these cutting edge chips 4 are provided. Is mounted directly on the tool body 1, while the other is slidably mounted in a groove 5 formed on the outer periphery of the tool body 1 along the direction of the generatrix of the cone formed by the tool body 1. The slider 6 is attached to the tip of the slider 6. Here, as shown in FIG. 3, the concave groove 5 has a pair of opposed wall surfaces 5a and 5b, and these wall surfaces 5a and 5b.
a, 5b, which is defined by a bottom surface 5c orthogonal to the bottom surface 5a and has a U-shaped cross section that opens to the outer peripheral side.
A spacer 7 is provided on the wall surface 5a facing the tool rotation direction T side of the a and 5b, and a plate 8 is provided on the wall surface 5b facing the rear side in the tool rotation direction T. I have.

The spacer 7 is a plate-like member formed so as to extend over substantially the entire length of the concave groove 5 when mounted on the tool main body 1. The spacer 7 is provided on the wall surface 5a and the bottom surface 5c of the concave groove 5. It is detachably attached by a pair of clamp screws 9 and 9 so as to be in close contact with each other, and on the inner side of the concave groove 5, that is, the side surface facing the tool rotation direction T side, as shown in FIG. A serration groove 7a having a wavy cross section is formed. On the other hand, plate 8
Is a plate-like member formed so as to extend over substantially the entire length of the concave groove 5, and is detachable so as to be sandwiched between the wall surface 5b of the concave groove 5 and the slider 6. A through hole 8a from the side surface facing the wall surface 5b.
Are drilled.

As shown in FIG. 1, the slider 6 is a prism-shaped member which is bent in the shape of a letter "C". The base end of the slider 6 is disposed in the groove 5. The cutting tip 4 is detachably mounted. At the base end of the slider 6, as shown in FIG. 3, a spacer 7 is attached to the wall surface 5 a side, that is, one of the side surfaces facing the rear side in the tool rotation direction T when mounted on the tool body 1. A serration groove 6a having a corrugated cross section is formed in close contact with the serration groove 7a.
The serration groove 6a is aligned with and engaged with the serration groove 7a of the spacer 7, and the other side surface 6b of the base end facing the tool rotation direction T is brought into close contact with the plate 8, and the lower surface 6c is further formed into a concave groove. 5 is attached to the groove 5 so as to be slidable along the generatrix direction in close contact with the bottom surface 5c.

On the wall surface 5b side of the concave groove 5, a plurality of mounting holes 5d penetrating perpendicularly to the wall surface 5b toward the outer peripheral surface of the tool body 1 are formed in the generatrix direction. The through portion of the hole 5d on the wall surface 5b side has a smaller diameter by one step, a female screw portion is formed on the inner periphery of the opening on the outer peripheral surface side, and a bush 10 is provided between the through portion and the female screw portion. Is inserted. Each of the mounting holes 5d is provided with a set screw 11 having a head portion having a male screw portion to be screwed into the female screw portion and a shaft portion that can be inserted into the through hole 8a of the plate 8. A disc spring 12 is fitted around the shaft portion of each set screw 11 so as to protrude from the through portion to the wall surface 5b and abut against the plate 8, so that the set screw 11 is screwed. The disc springs 12...
Is pressed against the spacer 7 side, and both serration grooves 6
a and 7a are firmly engaged with each other.

Further, a mounting hole 1a having a circular cross section is formed along the axis O from the rear end inside the tool body 1, and a coupling 13 is fitted into an inner periphery of the mounting hole 1a for mounting. Have been. As shown in FIG. 4, the coupling 13 is a member having a substantially cylindrical outer shape, and the outer periphery thereof has a key mounting groove 1 parallel to the center line of the coupling 13.
The key groove 1b extending parallel to the axis O is formed in the inner periphery of the mounting hole 1a at the same position as the position where the concave groove 5 is formed in the circumferential direction.
By fitting the key 13b into the key groove 1b, the coupling 13 is inserted into the mounting hole 1a with the center line thereof coincident with the axis O, and the coupling 13 is inserted into the tool body 1 and the axis O. Can be rotated around one body, and the mounting hole 1a
In the direction of the axis O. The inner peripheral portion of the coupling 13 has an inner diameter changed in multiple steps, and a slide shaft (not shown) is attached to the inner peripheral portion, so that the coupling 13 moves forward and backward in the axis O direction. Further, the chuck spindle is inserted into the inner periphery of the slide shaft, so that the hole drilling tool can move forward and backward independently of the movement of the coupling 1. Reference numeral 13c in the figure denotes a recess formed in the coupling 13 for accommodating the rear end of the clamp mechanism 3.

Further, the outer periphery of the distal end of the coupling 13 is formed in a tapered surface shape whose diameter gradually decreases toward the distal end, and the taper angle is such that the bottom surface 5 c of the concave groove 5 is formed by the tool body 1. Is made equal to the inclination angle made with respect to the axis O. In the outer peripheral portion of the front end, a connection hole 14 having the same center as the key mounting groove 13a in the circumferential direction and extending toward the inner peripheral side perpendicular to the tapered surface formed by the outer peripheral portion of the front end is formed. The connecting hole 14 is formed in a long hole shape extending in the circumferential direction of the coupling 13 as shown in FIG. 5 is formed to extend in a direction perpendicular to the generatrix direction (a direction perpendicular to the drawing of FIG. 1). Accordingly, the connection holes 14 facing the inner and outer circumferences of the coupling 13 are opposed to each other.
In the present embodiment, the pair of wall surfaces 14a, 14a are also arranged perpendicular to the generatrix direction, oppose the generatrix direction, and extend in the circumferential direction parallel to each other in the direction orthogonal to the generatrix direction. The width of the wall surfaces 14a, 14a in the extending direction is
a, 14a.

On the other hand, the tip end portion of the mounting hole 1a of the tool body 1 is formed in a tapered surface shape whose taper angle is equal to that of the outer peripheral portion of the tip end of the coupling 13 and whose inner diameter is gradually reduced toward the tip end side. At the same position as the key groove 1b in the circumferential direction, and overlaps with the bottom surface 5c of the concave groove 5, whereby the bottom surface 5c of the concave groove 5 is formed.
Is formed with a communication hole 5e for communicating the concave groove 5 with the mounting hole 1a. Therefore, the connection hole 14 of the coupling 13 attached to the attachment hole 1a is
It opens to face this communication hole 5e, toward the rear end side perpendicular to the bottom surface 5c of the concave groove 5 toward the inner peripheral side, and in the direction perpendicular to the generatrix direction toward the circumferential direction of the tool body 1. It will be arranged to extend. The base end of the slider 6 is perpendicular to the lower surface 6c, that is, the bottom surface 5c of the concave groove 5 when attached to the concave groove 5.
Through the base end so as to be perpendicular to the communication hole 5
e, a connecting pin mounting hole 6d which opens to face e.
The connection pin 16 is attached by 5, and the tip of the connection pin 16 is projected from the communication hole 5 e into the attachment hole 1 a and fitted into the connection hole 14 of the coupling 13.

As shown in FIG. 5, the connecting pin 16 has a head 16a having a decentered octagonal section at its rear end, and concave portions on both sides thereof for engaging with the heads of the clamp screws 15, 15, respectively. 16b, 16b are formed, and a distal end side thereof is formed as a substantially cylindrical shaft portion 16c. Of these, further, when mounted on the slider 6, protrudes vertically from the lower surface 6c and extends from the communication hole 5e through the mounting hole 5e. 1a is provided with a concave groove 5 of the slider 6
A pair of side surfaces 16d, 16d, which are perpendicular to the generatrix direction and are parallel to each other, are formed so that both side portions facing the generatrix direction side are cut off in the mounting state. Are arranged in parallel with the wall surfaces 14a, 14a of the coupling hole 14 of the coupling 13 attached to the attachment hole 1a. The width between the side surfaces 16d, 16d is such that the front ends of the connection pins 16 are in contact with the connection holes 14 of the coupling 13 as the side surfaces 16d, 16d face the wall surfaces 14a, 14a, respectively. When the coupling hole 14 is attached to the attachment hole 1 a of the coupling 13, the tool body 1
The connecting pin 16 is formed in the shape of a long hole extending in the direction perpendicular to the generatrix direction in the circumferential direction of the connecting pin 16 with the side surfaces 16d, 16d slidingly contacting the wall surfaces 14a, 14a. Within a range in which the extension 14 extends, the connection hole 14 is slidably inserted in the direction perpendicular to the generatrix direction toward the circumferential direction of the tool body 1.

Such a cutting tool includes the bush 2,
A coupling 13 is provided in the mounting hole 1a of the tool body 1 on which the clamp mechanism 3 and the two cutting blade tips 4 and 4 are mounted.
Is mounted by fitting the key 13b into the key groove 1b, and furthermore, the slider 6 to which the remaining cutting tip 4 is mounted is sandwiched between the spacer 7 and the plate 8 and is inserted into the concave groove 5, and the clamp screws 9, 9 are inserted. And a set screw 11... And a coned disc spring 12. It is assembled by projecting and inserting it into the connection hole 14 of the coupling 13 as described above, and fixing the connection pin 16 to the slider 6 by the clamp screws 15.

In the cutting tool having the above structure, when the connecting pin 16 is attached to the slider 6 and its tip is inserted into the connecting hole 14 of the coupling 13, the connecting pin mounting hole 6d of the slider 6 is used. Due to the molding error of the connecting pin 16 or the forming error of the connecting hole 14 of the coupling 13, a displacement in the circumferential direction of the tool body 1 occurs at the insertion position between the distal end of the connecting pin 16 and the connecting hole 14. In this embodiment, the wall surfaces 14a, 14a of the connection hole 14 and the side surfaces 16d,
As long as the parallelism with 16d is ensured, the connecting pin 16 is slidable in the circumferential direction of the tool body 1 with respect to the connecting hole 14 as described above. The connecting pins 16 can be inserted into the connecting holes 14 by sliding the side surfaces 16d, 16d against the wall surfaces 14a, 14a at the position.
The coupling 13 and the slider 6 are connected via the connecting pin 16, so that the slider 6 can be slid in the generatrix direction as the coupling 13 advances and retreats. Therefore, according to such a cutting tool, the coupling 13 cannot be connected to the slider 6 due to molding error or the like without providing the slider 6 with a mechanism for adjusting the position of the connection pin 16 in the circumferential direction. In addition, it is possible to prevent the occurrence of an inconvenience, to simplify the structure of these parts, and to eliminate the necessity of unnecessarily high molding accuracy in the manufacture thereof.

In the present embodiment, when the connecting pin 16 is slidably inserted into the connecting hole 14 in the circumferential direction of the tool body 1 as described above, the connecting hole 14 is The connection hole is formed in a long hole shape extending in a direction orthogonal to the generatrix direction, for example, the connection hole is formed in a square cross section or a rectangular shape extending in the generatrix direction, and the connection pin is also fitted into the connection hole. The size of the connecting pin 16 must be limited as compared with the case where the connecting pin 16 is formed in a rectangular cross section extending in the generatrix direction, which is slidable in the circumferential direction. Connection hole 1
4, while ensuring a sliding contact area between the connecting pin 16 and the connecting hole 14 so that the connecting pin 16 and the connecting hole 14 can be securely engaged in the generatrix direction. 6 can be slid more accurately. Moreover, in the present embodiment, the connection hole 14 is formed of a pair of parallel wall surfaces 14a, 1a facing each other in the generatrix direction.
4a, the connecting pin 16 is formed with a pair of mutually parallel side surfaces 16d, 16d which can slide on the wall surfaces 14a, 14a.
It is possible to secure a larger sliding contact area between the connecting pin 16 and the connecting hole 14, whereby the connecting pin 16 and the connecting hole 14 can be reliably engaged in the generatrix direction.

In this embodiment, the connecting holes 1
4 is a pair of mutually parallel wall surfaces 1 facing each other in the generatrix direction.
4a, 14a, and a pair of parallel side surfaces 16d, 16d, which are slidable on the wall surfaces 14a, 14a, are formed in the connecting pin 16; By making the cross section circular in a possible diameter, it is possible to engage in the generatrix direction and to be slidable in the circumferential direction. In the present embodiment, when the connecting pin 16 is slidably fitted in the connecting hole 14 in the circumferential direction of the tool body 1, the connecting hole 14 is formed in a long hole shape extending in a direction orthogonal to the generatrix direction. Although the connecting pin 16 is slidable in a direction orthogonal to the lever generatrix direction, especially when the connecting pin is circular in cross section as described above, the connecting hole is formed in a conical surface centered on the axis O. The coupling hole may be formed so as to open in an arc shape on the tapered surface of the outer peripheral portion of the distal end of the coupling 13. In this case, for example, the coupling hole and the key attachment Even if the center of the groove 13a is displaced in the circumferential direction, or the key groove 1b of the mounting hole 1a is also displaced in the circumferential direction from the predetermined position, the connecting pin can be engaged in the generatrix direction and the circumferential direction. (However, in this case It can be fitted to ensure that the connecting hole as slidable toward the circumferential direction) centered on the axis O.

[0023]

As described above, according to the present invention,
A connecting pin attached to a slider slidable along the generatrix direction of the outer periphery of the tool body is capable of engaging with the coupling hole formed in the coupling in the generatrix direction and facing the circumferential direction of the tool body. Because it can be slidably inserted,
Even if these parts have molding errors or variations in accuracy, it is possible to prevent the connection pin from being unable to be inserted into the connection hole without requiring an adjustment mechanism with a complicated structure, and to ensure reliable coupling. And the slider can be connected.

[Brief description of the drawings]

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

FIG. 2 is a front view of the embodiment shown in FIG. 1 as viewed from a distal end side.

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

FIG. 4 is a front view, (b) sectional side view, and (c) of the coupling 13 of the embodiment shown in FIG.
(B) View in the Y direction, (d) Z in (b)
It is a figure of a direction view.

FIG. 5 is (a) of the connecting pin 16 of the embodiment shown in FIG. 1;
It is the figure which looked at the partially broken side view, (b) front-end | tip side (shaft part 16c side).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tool main body 1a Mounting hole 4 Cutting edge chip 5 Depressed groove 5e Communication hole 6 Slider 7 Spacer 8 Plate 13 Coupling 14 Connection hole 14a Wall surface of connection hole 14 Connection pin 16d Side face of connection pin 14 O Axis line of tool body 1 T Tool rotation direction

Continued on the front page (72) Akira Venus Inventor 1528 Nakashinden, Yokoi, Kobe-cho, Yasuhachi-gun, Gifu Prefecture F-term in Mitsubishi Materials Corporation Gifu Works (reference) 3C046 LL07

Claims (3)

[Claims] 1. A slider provided with a cutting edge tip is slidably mounted in a groove formed along a generatrix of a tool body having a substantially frusto-conical shape and rotated around an axis. At the same time, a coupling is attached to the mounting hole formed in the tool main body so as to be integrally rotatable with the tool main body and to be able to advance and retreat in the axial direction. The coupling includes the concave groove and the mounting hole. While the connection hole that opens facing the communication hole that communicates is formed, the slider has
A connection pin is provided which protrudes from the communication hole into the attachment hole and is inserted into the connection hole so as to be freely protruded and retracted. The connection pin is engageable with the connection hole in the direction of the generatrix and the periphery of the tool body. A cutting tool, which is slidably fitted in a direction. 2. The connecting hole according to claim 1, wherein the connecting hole is formed in a slot shape extending in a circumferential direction of the tool main body with a width in which the connecting pin can be inserted in the generatrix direction.
The cutting tool according to 1. 3. The connecting hole has a pair of parallel wall surfaces facing each other in the generatrix direction, and the connecting pin has a pair of parallel side surfaces slidable on the wall surfaces. The cutting tool according to claim 1, wherein the cutting tool is formed.