JPH1094906A - Replacement type tip mounting structure for cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform replacement in a state of visually confirming a receiving surface, side wall, etc., of a shank by rotating a retaining metal in the case of replacing a tip. SOLUTION: A replacement type tip mounting structure is constituted such that in order to mount a tip 2, in a tip end of a shank 1, a recessed part 1A opened to a tip end side is formed, the tip 2 relating to the shank 1 is tightened from upward through a retaining metal 5 by a mounting means 3 and 1B, and the tip 2 and the retaining metal 5 are locked to each other by a lock means 5a and 2a in the case of tightening. The structure, in the case of tightening, is constituted by forming mutual contact tilt surfaces 1C, 5c for generating component force pressing from upward and component force pressing the tip to a side wall side in the shank and a retaining metal side. Here, the tilt surface 5c is constituted by a tilt surface of round shape as viewed by plane with a lock center locking the shank and the retaining metal by the mounting means serving as the center.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool replacement structure for a cutting tool used for cutting various machine tools such as a lathe and a machining center.

[0002]

2. Description of the Related Art In recent years, a replaceable chip is detachably attached to a blade of a cutting tool used in a machine tool. Is rotated to cut with a new blade on another side. Then, when the blades formed on all sides of the chip are worn, a mode of use is adopted in which the chip is replaced with another chip for cutting.

[0003] By the way, as a structure in which the above-mentioned tip is detachably attached to a "shank" constituting a base of a cutting tool, a type generally called a "one-action type" has conventionally been adopted. That is, as an embodiment of this “one-action type” mounting structure, as shown in FIG. 3, the tip 2 is disposed in a predetermined recess 1A of the shank 1 and is inserted into a screw hole B formed in the shank 1. When the mounting bolt 3 is mounted, the tip 2 is pressed and fixed in one direction to the shank 1 by the axial force.

However, in the case of the "one-action type" mounting structure shown in FIG. 3, the above-mentioned axial force is applied to the tip 2 via the "L" -shaped cantilever R to divide the tip 2 into the side wall of the recess 1A of the shank 1. 1b, when the mounting bolt 3 is firmly tightened, on the contrary, as shown in FIG. 3, the tip portion of the tip 2 rises up from the receiving surface 1a of the shank 1. , Chip 2
A clearance is created between the lower surface of the shank and the receiving surface 1a of the shank. On the other hand, in the state where the mounting bolts are loosely tightened, when stress acts on the chip 2 during cutting, the chip 2 separates from the receiving surface 1a of the shank 1 or "chatter" occurs even if the chip 2 does not separate. This causes a situation where the tip is damaged.

[0005] In view of such a situation, a type called a "double clamp type" as shown in FIG. 4 has been developed. As shown in FIG. 4, the mounting structure of this "double clamp type" is such that the mounting bolt 3 is
When the screw is screwed into the screw hole 1B formed on the shank 1, the bottom surface of the holding member 5 and the inclined surfaces 5c and 1C formed on the shank 1 are joined, and the axial force generated by the mounting bolt 3 is reduced.
The force (component force) pressing the chip 2 from above and the shank 1
As a result, the tip 2 is reliably pressed against the receiving surface 1b and the side wall 1a of the shank 1, so that the tip 2 is disperse | distributed to the force (component force) which presses the side wall 1b. Compared with the structure, the attachment can be performed more reliably and in a stable state.

However, in the case of the "double clamp type" mounting structure shown in FIG. 4, since the inclined surfaces 5c and 1C are formed linearly in plan view, the holding metal 5 is attached to the shank 1. In order to position the protruding piece 5b on the bottom surface of the holding metal 5 and a positioning hole 4A for fitting the protruding piece 5b on the shank side so that the protruding piece 5b can be positioned in a predetermined state.
In the case of a normal chip exchange in which the holding metal 5 is not completely removed until the state shown in FIG. 4B in the chip replacement, the holding metal 5 interferes with the chip replacement. Invisible except for the tip,
In a state where the chip is removed, the receiving surface 1a and the side wall 1b of the shank 1 cannot be completely visually recognized. Therefore, in a state where chips and the like often accumulate between the receiving surface and the side wall, a new chip is removed. Will be attached to the shank,
When replacing the chip, the chip cannot be mounted in a predetermined state, that is, the chip is mounted in a state where it is partially lifted up or not pressed firmly from above. Was presenting. In FIG. 4, reference numeral 6 denotes a chip receiving washer.

Further, even if chips are cleaned with air or the like when attaching the chips, the chips attached to the receiving surface or the side wall cannot be visually recognized, so that the chips can be reliably cleaned. It was difficult in practice.

The present invention has been made in view of such a situation, and it is possible to securely fix a chip to a shank, and at the time of chip replacement, rotate a presser foot to visually recognize a receiving surface and a side wall of the shank. It is an object of the present invention to provide an exchangeable tip mounting structure for a cutting bit, which can be replaced in a state where it can be performed.

[0009]

According to a first aspect of the present invention, there is provided an exchangeable chip mounting structure for a cutting tool according to the present invention. Then, the tip is pressed against the shank from above by a fixing means via a press fitting which presses the shank, and the tip and the press fitting are locked to each other by a locking means during the tightening. A cutting tool formed by forming inclined surfaces that are in contact with each other on the shank and the holding member side to generate a component force for pressing the holding member from above and a component force for pressing the chip to the side wall side during the tightening. In the exchangeable tip mounting structure of the above, the inclined surface is formed as a round inclined surface in a plan view, centering on a restraining center at which the attaching means restrains the shank and the holding metal. It is characterized in that is.

However, according to the exchangeable chip mounting structure of the cutting tool configured as described above, when the tightening of the mounting means is loosened at the time of replacing the chip, the holding metal pivots about the restraining center. Thus, the holding metal can be avoided from a position above the concave portion (tip) of the shank. Therefore, at the time of chip replacement, it is visually confirmed whether or not chips are attached to the receiving surface and the side wall of the concave portion of the shank, and if they are attached, they can be easily removed by pressurized air or the like. Also, when detaching the chip, the chip can be surely detached to a predetermined portion while visually recognizing the chip.

Of course, since the inclined surface is formed as described above by tightening with the attaching means, a component force for pressing the holding member from above and a component force for pressing the chip toward the side wall are generated. The tip can be fixed in a so-called "double clamp type", and when tightened, the tip can be securely and stably attached to the shank.

According to the second aspect of the present invention, in the cutting tool replacement structure for a cutting tool, a recess is formed at a tip end of the shank at the tip end side for attaching a tip. The chip is tightened from above by a screwing means consisting of a mounting bolt and a screw hole via a holding metal member for pressing, and the chip and the holding metal member are engaged with a locking hole and a locking piece during the tightening. Inclined surfaces which are mutually locked by a locking means comprising: a locking component for generating a component force for pressing the holding metal from above and a component force for pressing the chip toward the side wall during the tightening. In the interchangeable tip mounting structure of a cutting bit formed on the shank and the holding bracket side, the inclined surface is centered on the mounting center of the mounting bolt and the screw hole,
It is characterized by being constituted by a round inclined surface in a plan view.

[0013] According to the exchangeable tip mounting structure for a cutting bit having the above-mentioned structure, when the mounting bolt is loosened with respect to the screw hole at the time of exchanging the tip, the holding metal is centered on the mounting center. It can be pivoted, and as a result, the holding metal can be avoided from the concave portion of the shank. Therefore, at the time of chip replacement, it is visually confirmed whether or not chips are attached to the receiving surface and the side wall of the concave portion of the shank, and if they are attached, they can be easily removed by air or the like. Also, when attaching and detaching chips,
While visually recognizing the chip, it can be securely attached to and detached from a predetermined site.

[0014]

In a second aspect of the present invention, there is provided a cutting tool replacement type mounting structure for a cutting tool according to the third aspect of the present invention, wherein the retaining piece formed on the holding metal is provided. With a hemispherical shape, even if the position of the chip and the holding metal is slightly shifted, the chip can be automatically moved to a predetermined position and positioned as the mounting bolt is tightened. In this respect, the configuration is excellent.

[0015] In the exchangeable chip mounting structure for a cutting tool according to any one of claims 2 and 3, the locking piece is formed on the holding metal, and the locking hole is formed on the tip side. A protruding piece is formed on the opposite side of the retaining piece of the holding metal with the bolt interposed, and a positioning hole for fitting the protruding piece on the shank side and a slide groove in a direction in which the holding metal is rotated from the positioning hole in a sector shape. When extended to
The positioning accuracy between the holding metal and the shank side can be improved, and the turning function of the holding metal can be maintained.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a cutting tool according to an embodiment of the present invention;

FIG. 1 is a view showing the structure of an exchangeable tip mounting structure for a cutting tool according to one embodiment of the present invention.
(A) is a cross-sectional view taken along the line II of (b), (b) is a plan view in a state where the holding metal is removed, and (c) is an enlarged view of the holding metal as viewed from the bottom direction.

In FIG. 1, reference numeral 1 denotes a shank, and at the tip of the shank 1, a recess 1A is formed which is open toward the tip. The recess 1A is made of ceramic, cermet, or the like.
A replaceable chip 2 made of carbide or the like is configured to be detachably attached. The bottom surface of the recess 1 </ b> A contacts the lower surface 2 b of the chip 2 via the washer 6.
a, and the side wall 1b becomes a wall surface to be joined to the side wall 2c of the chip 2. Therefore, the chip 2 is configured such that the lower surface 2b and the two rear side walls 2c abut on the receiving surface 1a of the recess 1A and two adjacent wall surfaces 1b.

The screw hole 1B is located behind the recess 1A.
The mounting bolt 3 is screwed into the screw hole 1B. The screw hole 1B is a stepped screw hole, and a coil spring 7 for preventing "rattle" and for preventing loosening is interposed in the enlarged diameter portion.

Further, behind the screw hole 1B, there is formed an inclined surface 1C which is lower and lower on the rear side. The inclined surface 1C is, as shown in the plan view of FIG. It is a round inclined surface in plan view centering on the screw hole 1B.

In the screw hole 1B, a slide groove 4 having a substantially fan shape in a plan view is formed integrally with its outer shell. That is, the slide groove 4 has a fan shape centered on the screw hole 1B.

The holding member 5 is detachably and tightly attached via the screw hole 1B and the mounting bolt 3. At the left end of the fan-shaped slide groove 4, FIG.
FIG. 1C shows a state in which the protruding piece 5b of the holding metal fitting 5 whose bottom surface is fitted and the mounting bolt 3 is loosened can be turned rightward in FIG. Have been. Also, the diameter of the mounting hole 5d of the holding metal member 5 is slightly larger than the mounting bolt 3, that is, a so-called "idiot hole". However, instead of making the diameter of the mounting hole 5d of the holding metal 5 slightly larger than the mounting bolt 3, as shown in FIG. It may be a long hole extending in the direction of inclination of the surface.

A hemispherical locking piece 5a is projected from the bottom surface of the tip of the holding metal fitting 5, and the center of the diamond-shaped chip 2 in plan view is larger than the diameter of the locking piece 5a. A locking hole 2a having a large diameter is formed.
(A)).

In addition, the rear part of the holding metal fitting 5 has a structure shown in FIG.
As shown in (a) and (b), an inclined surface 5c joined to the inclined surface 1C is formed. That is, the inclined surface serving as the inner surface of the rear part of the holding member 5 is formed in a round shape in plan view.

As shown in FIG. 1A, the receiving washer 6 is detachably fixed to the engaging hole 2a by a circlip 8.

Thus, the exchangeable tip mounting structure of the cutting tool having the above-described structure is used for exchanging the tip.
In addition, it acts as follows to fix the tip to the shank.

That is, when the chip is to be replaced with a new one, when the mounting bolt 3 is loosened, the holding metal 5 pivots around the mounting bolt 3 in the counterclockwise direction in FIG. At this time, the protruding piece 5 b formed on the bottom surface of the holding member 5 passes through the fan-shaped slide groove 4.

In this state, the chip 2 is exposed above the shank 1.

Then, the old chip 2 is removed while visually recognizing in this state, and if dust such as cuttings is attached to the receiving surface 1a or the side wall 1b of the recess 1A, pressurized air from the air nozzle is used. These dusts are removed.
Such cleaning of the receiving surface 1a or the side wall 1b of the concave portion 1A can be reliably performed while being visually recognized.

After the cleaning, the new chip 2 is placed in a predetermined position of the recess 1A of the shank 1, that is, the two side walls 2c behind the chip 2 abut against the side wall 1b of the recess 1A.
Is arranged such that the bottom surface of the contact member comes into contact with the receiving surface 1a. At the time of this arrangement, as described above, the holding metal fitting 5 also pivots to rotate the recess 1A.
Since it is retracted from the upper position, it can be performed accurately and quickly while visually recognizing.

After the tip 2 is disposed in the recess 1A of the shank 1 as described above, the holding metal 5 is turned clockwise, that is, the projection 5b is
Is turned clockwise until it touches the left end of the
(See the two-dot chain line in (b)).

When the mounting bolt 3 is tightened in this state, the locking piece 5a of the holding metal fitting 5 is engaged with the locking hole 2a of the chip 2, and at this time, the locking piece 5a has a hemispherical shape. Therefore, even if the position of the chip 2 is slightly displaced, the chip 2 can be automatically moved to a predetermined position by being tightened with the mounting bolt 5 and mounted in an accurate position. At this time, when the mounting bolt 5 is tightened, the holding metal 5
And the inclined surface 1C of the shank 1 are joined,
The pressing metal 5 is pressed from above while being pressed in the direction to move it backward (see FIG. 1).

Therefore, the chip 2 is fixed to the receiving surface 1a and the side wall 1b of the recess 1A of the shank 1 while being securely pressed. And, as described above, the tip 2 is pressed in the state where the holding metal fitting 5 is precisely positioned at the predetermined position by the protruding piece 5b, so that the tip 2 is accurately positioned at the predetermined position with respect to the shank 1. And it can be fixed securely.

[0034]

According to the exchangeable chip mounting structure for a cutting tool according to the present invention, the chip is exposed on the upper surface when the chip is exchanged, so that the chip can be easily removed. In addition, since the shank recess after removal is also exposed on the upper surface, even if dust such as cutting chips is attached, it can be easily visually recognized. Becomes possible.

Since a new chip can be attached with the concave portion exposed upward as described above, it is possible to reliably dispose the chip at a predetermined position, and a slight displacement of the chip in a plane is avoided. By tightening the holding metal, it is automatically corrected to a predetermined position and fixed.

As a result, unnecessary damage and dropping of the chip, which has conventionally occurred due to incomplete mounting of the chip, can be prevented, and the yield of the processed product can be improved. It becomes possible.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing a configuration of an exchangeable tip mounting structure for a cutting tool according to an embodiment of the present invention, wherein FIG. 1A is a cross-sectional view taken along the line II of FIG. 1B and FIG. FIG. 3C is a plan view showing the state in which the metal fitting is removed, and FIG.

FIG. 2 is an enlarged view of a holding member according to another embodiment as viewed from a bottom surface direction.

FIG. 3 is a cross-sectional view of a main part showing a conventional single-action type cutting tool replacement type chip mounting structure.

FIGS. 4A and 4B are diagrams showing a conventional double clamp type cutting tool replacement type chip mounting structure, in which FIG.
-II cross section taken along a plane view in a state excluding the Ri preparative (b) is retainer member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Shank 1A ... Depression 1B ... Screw hole (one of attachment means) 1C ... Inclined surface 2 ... Tip 2a ... Locking hole (one of locking means) 3 ... Mounting bolt (one of mounting means) Reference numeral 5: Hold down fitting 5a: Locking piece (one of locking means) 5c: Inclined surface

Claims (4)

[Claims] In order to attach a chip, a concave portion opened on the tip side is formed at the tip of the shank, and the attaching means is attached to the shank via a holding metal which presses the chip from above. The chip and the holding member are configured to be locked to each other by locking means during the tightening, and a component force for pressing the holding member from above and a portion for pressing the chip toward the side wall during the tightening. In a replaceable chip mounting structure for a cutting tool, in which inclined surfaces for generating force are formed on a shank and a holding metal side, the inclined surfaces contacting each other, wherein the inclined surface includes a shank and a holding metal. An exchangeable chip mounting structure for a cutting bit, comprising a round inclined surface in plan view with a center of restraint as a center. 2. A tip portion of the shank is provided with a concave portion opened on the tip side for attaching the tip, and a mounting bolt and a screw are provided via a holding metal member for pressing the tip against the shank from above. The tip and the holding member are configured to be fastened by screwing means comprising a hole, and to be mutually locked by the fastening means comprising a locking hole and a locking piece during the tightening. In order to generate a component force that presses the presser from above and a component that presses the chip toward the side wall, a replaceable insert for a cutting tool, in which inclined surfaces that contact each other are formed on the shank and the presser side. The mounting structure, wherein the inclined surface is formed as a round inclined surface in a plan view, centering on the mounting center of the mounting bolt and the screw hole. -Up mounting structure. 3. An exchangeable chip mounting structure for a cutting bit according to claim 2, wherein said retaining piece formed on said holding member is formed in a hemispherical shape. 4. A locking piece is formed on the holding metal, a locking hole is formed on the chip side, and a protruding piece is formed on the opposite side of the locking piece of the holding metal with a mounting bolt interposed therebetween, and a shank is provided. 4. An exchangeable tip for a cutting bit according to claim 2 or 3, wherein a positioning hole into which the protruding piece is fitted on the side, and a slide groove extending in a fan shape from the positioning hole in a direction in which the holding metal is turned. Mounting structure.