JP3597998B2 - Cutting tools - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cutting tool used for cutting a columnar work or forming a circumferential groove on the outer circumference or inner circumference thereof.
[0002]
[Prior art]
Conventionally, as the cutting tool, as shown in FIG. 5, the tip end of the tip 32 provided with the cutting blade 31 on the tip upper surface is provided on the tip seat portion 35 recessed in the tip lateral surface of the holder 34 by the holding plate 33. A cutting tool 30 of a type that is fixed by pressure contact is used.
[0003]
Since the cutting tool 30 is installed so that the back surface 36 side of the chip seat portion 35 is exposed from the machine, a fixing screw 37 is inserted from the back surface 36, and a screw hole 38 provided in the holding plate 33 and a fixing screw 37 are formed. By screwing the distal end, the holding plate 33 is pulled toward the chip seat 35, and as a result, the holding plate 33 presses and fixes the chip 32 to the chip seat 35 of the holder 34.
[0004]
However, in the conventional cutting tool 30 described above, since the holding plate 33 and the fixing screw 37 are engaged only with the screw groove fitting in the screw hole 38, the drawing force cannot be sufficiently increased. Since the force acts only on a very narrow area in the vicinity of the screw hole 38, the force for press-fixing the tip is transmitted non-uniformly depending on the location, and the fixing of the tip 32 becomes unstable. There have been problems such as vibration and damage to the chip 32 and the holder 34 due to the vibration.
[0005]
[Problems to be solved by the invention]
In view of the above problems of the prior art, the present invention provides a cutting tool used for cutting a columnar work or forming a circumferential groove on the outer or inner circumference thereof, which has a large chip fixing force and generates chatter vibration. It is an object to provide a cutting tool that is difficult to perform.
[0006]
[Means for Solving the Problems]
In order to solve the problems of the prior art, the cutting tool of the present invention mounts a throwaway tip on a narrow lower jaw protruding forward of a prismatic holder, and at a position near the rear side of the lower jaw. A blade-like press fitting is fitted and fixed with two fixing screws in the recessed pocket, and the upper jaw provided on the press fitting presses the upper surface of the throw-away tip, and the throw-away tip is inserted between the upper and lower jaws. In the configuration, two through holes and two screw holes for the fixing screw are provided at horizontal positions of the press fitting and the pocket of the holder, respectively, and a vertical direction from a lower surface between the through holes of the press fitting. A slit is formed to extend between the through hole and the screw hole so that when the throw-away tip is attached, the slit expands so that the front side of the presser fitting is drawn downward and the rear side is drawn backward. Characterized in that eccentrically to the shaft position.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0008]
FIG. 1 is an exploded perspective view of a cutting tool 1 of the present embodiment. The cutting tool 1 projects forward of a prismatic holder (hereinafter abbreviated as a holder) 2 made of quenched tool steel or carbide. A throw-away tip (hereinafter, abbreviated as a tip) 5 is placed on the narrowed lower jaw 2a, and two fixing screws 8 are inserted into a pocket 4 recessed near the rear side of the lower jaw 2a. The upper surface of the chip 5 is pressed by the upper jaw 6a provided on the presser 6 by fitting and fixing the blade-like presser 6 so that the chip 5 is sandwiched between the upper and lower jaws (2a, 6a). This is the cutting tool 1 obtained. As shown in the figure, the cutting tool 1 is provided with two through holes 7 for the fixing screw 8 and two screw holes 10 at horizontal positions of the holding metal 6 and the pocket 4 of the holder 2 respectively. I have.
[0009]
The tip 5 has a narrow, substantially rectangular column shape, and is formed with a cutting edge ridge 5a and a rake face 5b continuous with the cutting edge ridge 5a at the front and rear ends of the upper surface, respectively. I have.
[0010]
The fixing method of the presser fitting is as follows. A fixing screw 8 is inserted into a through hole 7 provided in the holding metal 6, and is further screwed into a screw hole 10 provided from the pocket 4 of the holder 2 to the back surface 9 thereof. Thus, the presser 6 is pressed, whereby the presser 6 presses and fixes the chip 5.
[0011]
In addition, the cutting tool 1 of the present embodiment is provided with a not-shown rotation groove for engaging with the tip of the hexagon wrench 21 or the tip of the driver on the tip of the fixing screw 8, and the turning of the tip is performed. An external screw and an internal screw of the screw hole 10 of the holder 2 are formed on the fixing screw 8 so that the screw becomes a right-handed screw or a left-handed screw when the fixing screw is turned by the groove. The rotation of the fixing screw 8 can be performed with a right-hand screw or a left-hand screw from the side.
[0012]
Further, the cutting tool 1 of the present embodiment is of the back-constrained type as described above, but it is not necessary to limit the present invention to the back-constrained cutting tool. However, the advantage of using the back-constrained type as in the above cutting tool 1 is that the tip 5 can be replaced without removing the holder 2 from the machine tool because the fixing screw 8 can be rotated from the back 9 side. There is.
[0013]
In addition, it does not matter whether it is a right-handed screw or a left-handed screw.
[0014]
Next, FIG. 2 shows a top view of the holder 2, and FIG. 3 shows a state where the cutting tool of FIG. 1 is assembled. For convenience of description, the fixing screw is omitted. As shown in FIG. 3, a slit 6b extending vertically from the lower surface is provided between the through holes 7 of the holding member 6, and the through holes 7 and the screw holes 10 are eccentric by a distance d. The direction of the eccentricity is such that the front through-hole 7 is upward with respect to the screw hole 10 and the rear through-hole 7 is rearward with respect to the screw hole 10. Further, the center axis of the through hole 7 provided in the holding member 6 and the center axis d of the screw hole 10 provided in the holder 2 are eccentric by about 0.2 to 0.5 mm, and the lower jaw 2a and the upper jaw 6a are eccentric. Was formed as a slope inclined rearward and downward.
[0015]
Therefore, when the fixing screw is tightened into the screw hole 10 when the chip 5 is mounted, the slit 6b expands so that the front side of the holding member 6 is drawn downward and the rear side is pulled backward, so that the holding member is pulled. 6 strongly presses the upper surface of the chip 5 rearward and downward, thereby strongly pulling the chip 5 toward the rear side of the holder 2, thereby increasing the fixing force of the chip 5 and reducing the problem of chatter vibration.
[0016]
As described above, in the cutting tool 1, when the tip 5 is mounted, the center axis positions of the through hole 7 and the screw hole 10 are different so that the slit 6b of the presser fitting 6 is expanded and the front side is drawn downward and the rear side is drawn rearward. It is characterized by the following.
[0017]
When the eccentric distance d between the through hole 7 and the screw hole 10 is less than 0.1 mm, there is a possibility that blurring or the like may occur. On the other hand, when the eccentric distance d exceeds 0.5 mm, the presser fitting 6, the chip 5, the lower jaw 2a. Etc. may be damaged.
[0018]
FIG. 4 is a front view of the cutting tool 1 shown in FIG. 1. As shown in FIG. 4, the tip contact surfaces of the lower jaw 2a and the upper jaw 6a are formed in a convex V shape, and the constraining surface of the opposing tip 5 is formed. Are formed in a concave V-shape so that they do not shift in the lateral direction. In order to sufficiently increase the strength of the convex V-shaped portion and the concave V-shaped portion, the V-shaped angle is preferably 90 ° or more. Further, it is preferable that the above-mentioned V-shaped angle is 150 ° or less from the viewpoint of restraining force.
[0019]
In the present embodiment, the tip contact surface of the lower jaw 2a and the upper jaw 6a is shown as a convex V-shape, but the relationship between the tip contact surface and the unevenness of the constraining surface of the chip 5 opposed thereto is shown. May be reversed.
[0020]
Another effect of the present invention is that, as described above, the force for restraining the chip 5 is very large and stable (not depending on the tightening force of the fixing screw, but on the spring force provided on the presser 6). Further, since the tip 5 is not pulled backward and moved forward, the edge position and the edge height of the tip 5 are always constant. Thereby, the processing accuracy can be made high.
[0021]
As described above, the embodiments of the present invention have been described in detail. However, it is needless to say that the present invention is not limited to these embodiments, and can take any form without departing from the object of the invention.
[0022]
【The invention's effect】
As described above, the cutting tool of the present invention has a structure in which a tip is clamped by a narrow lower jaw protruding forward of a prismatic holder and an upper jaw provided on a presser fitting. Two fixing holes and two screw holes for the fixing screw are provided, and the holding metal is fastened with the two fixing screws. Further, between the through holes of the holding metal, a vertical direction is formed from the lower surface. An elongated slit is provided and the through hole and the screw hole are eccentric, so that when the chip is mounted, the slit expands so that the front side of the presser fitting is drawn downward and the rear side is drawn rearward, so that the presser fitting is mounted on the upper surface of the chip. Is strongly pressed rearward and downward, whereby the tip is strongly pushed behind the lower jaw, and the fixing force of the tip is increased, so that the problem of chatter vibration is less likely to occur.
[0023]
Further, since the tip is not pulled backward and displaced forward, the edge position and the edge height of the tip are always constant. Thereby, the processing accuracy can be made high.
[0024]
As described above, the cutting tool of the present invention has a very excellent effect that the tip fixing force is large and chatter vibration is hardly generated.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a cutting tool according to the present invention.
FIG. 2 is a top view of a holder constituting the cutting tool of FIG.
FIG. 3 is a side view of the cutting tool of FIG. 1;
FIG. 4 is a front view of the cutting tool of FIG. 1;
5 (a) is a plan view, FIG. 5 (b) is a top view, FIG. 5 (c) is a front view, and FIG. 5 (d) is a front view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cutting tool 2 Holder 2a Lower jaw part 3 Side surface 4 Pocket 5 Tip 5a Cutting blade ridge 5b Rake surface 6 Holding metal 6a Upper jaw part 6b Slit 7 Through hole 8 Fixing screw 9 Back surface 10 Screw hole 11 Screw head 21 Hex wrench d Eccentric distance

Claims (1)

A throw-away tip is placed on a narrow lower jaw protruding forward of the prismatic holder, and a blade-like presser is held by two fixing screws in a pocket recessed near the rear side of the lower jaw. A cutting tool configured to fit and fix a metal fitting and press an upper surface of the throw-away tip by an upper jaw provided on the presser fitting, thereby sandwiching the throwaway tip between upper and lower jaws, wherein the presser fitting and the holder are provided. Each of the pockets has two through holes and two screw holes for the fixing screw at the horizontal position, and when the throw-away tip is mounted, the holding metal fitting has a slit expanded so that the front side is downward and the rear side is rearward. A cutting tool wherein the central axis positions of the through hole and the screw hole are eccentric so as to be drawn.

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