JPS639922B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a tool holder equipped with a tool that rotates the tool or the workpiece and cuts the largest dimension of the workpiece with one cutting edge. .

(Prior Art) The need to adjust machining dimensions without moving the center of rotation using the same tool has been keenly felt. For example, when drilling a hole with a drill, if the cutting edge becomes slightly worn and the hole diameter decreases to a point where it deviates from the controlled dimensions, it may be necessary to remove it and re-grind it or replace the drill, even if the cutting edge is strong enough to withstand cutting. Must be. If machining dimensions can be easily adjusted in such a case without removing the drill, it is possible to expect a reduction in tool costs and machining time. Furthermore, indexable drills and indexable end mills cannot be used for machining that requires precision unless changes in machining dimensions due to chip corner changes or chip replacements can be adjusted. Therefore, various proposals have been made regarding methods of adjusting processing dimensions. For example, in the tool shown in Fig. 1 (Special Publication No. 58-1065), the tool body A
Adjustment is made by attaching a cutting blade B to the tip of the body A and inserting a wedge D screwed into the body A into the body A, which is screwed into a bolt C screwed into the middle of the body, and is mainly used for minute adjustments in boring processing, etc. However, (a) it is not possible to quantitatively manage the amount of adjustment. (b) Rigidity decreases because a cut is made in the tool body. (c) The direction in which you can adjust by tightening the adjustment bolt is good, but it is unstable in the direction in which you want to adjust by loosening it. There were drawbacks such as:

Furthermore, what is shown in Figure 2 (Japanese Patent Application Laid-Open No. 59-19610)
In , the projection 12 from the center of the tool body A is fixed to the spindle E via the eccentric sleeve 14 at an arbitrary position, so the relationship between the maximum eccentric position of the eccentric sleeve 14 and the position of the cutting edge B is cannot be confirmed and the adjustment amount for the rotation angle of the eccentric sleeve 14 cannot be calculated.

Furthermore, although they are all effective for use within a limited range through trials, stepless quantitative adjustment is not possible.

(Objective of the Invention) The present invention aims to correct the drawbacks of the above-mentioned proposals, and to provide a tool holder that can perform the necessary dimensional adjustments steplessly, accurately and quantitatively, has excellent rigidity, and has good operability. It is something to do.

(Description of Embodiments) Hereinafter, an embodiment in which the present invention is applied to a throw-away type drilling tool will be described with reference to FIGS. 3 and 4.

In FIG. 3, 1 is the machine mounting side of the tool holder, hereinafter referred to as the main body. Reference numeral 2 denotes the side on which the tool is attached, hereinafter referred to as the grip cylinder. A shank 6 for attachment to a machine protrudes from the center of the main body 1, and is further provided with a base circle outer circumferential portion 9 that fits with an inner diameter surface 7 of an inclined plate 3 and an inner surface 8 of a holder of a grip cylinder 2, which will be described later.
A side wall 10 of the base circle outer circumferential portion 9 of the main body 1 is an end face opposite to the end face 21 of the grip cylinder 2, and is finished in a plane perpendicular to the rotation center line 11 of the main body 1. Furthermore, an escape hole 14 is bored in the center of the end surface 13 of the main body 1 on the grip cylinder 2 side so that even if the shank 12 of the tool protrudes from the end surface of the grip cylinder 2, it will not interfere with the main body 1. The inclined plate 3 fitted into the base circle outer circumferential portion 9 of the main body 1 is an annular plate, and its inner diameter surface 7 is formed concentrically with the rotation center line 11 of the main body 1, and the side end surface 27 of the main body 1 is The flat surface is perpendicular to the inner diameter surface 7, and the end surface on the side of the gripping cylinder 2 has an inclined surface 28 which is not perpendicular to the inner diameter surface. Two screw holes 15 for fixing the holding cylinder 2 and the inclined plate 3 to the main body 1 with bolts 30 are provided in two symmetrical places in the main body 1 and the gripping cylinder 2, respectively, and further, the main body 1 and the gripping cylinder 2 are fixed with respect to the rotation direction. Positioning pin 16 to keep it in a constant position at all times
A driving hole 17 is drilled at one location. The outer circumference of the shank 6, the base circle outer circumference 9, the relief hole 14, and the pitch circles of the screw hole 15 and the driving hole 17 are all concentric with the rotation center line 11 of the main body 1.

In order to fix the shank 12 from the outer periphery of the grip tube 2 toward the center of the attachment hole 18 by providing a mounting hole 18 in the center of the grip tube 2 in which the shank 12 of the tool fits with precision. A screw hole 20 into which a bolt 19 is screwed is provided to penetrate to the mounting hole 18. Furthermore, an inner surface 8 that fits into the base circle outer circumferential portion 9 is provided concentrically with the mounting hole 18 at the end of the gripping tube 2 on the main body side, and an end surface 21 of the gripping tube that contacts the inclined surface 28 of the inclined plate 3 is provided with the mounting hole 18. It is finished in a plane perpendicular to the center line 22 of. Further, on the opposite end surface 23, there is a bolt 30 that is fixed to the main body 1 together with the grip cylinder 2 and the inclined plate 3.
A bolt hole 24 for inserting, a counterbore hole 31, and an elongated hole 25 that fits the positioning pin 16 are drilled.
There is a scale 26 on the outer circumference to indicate the amount of adjustment.
It is carved between 180 degrees. Note that the scale can be provided on the main body 1 instead of the grip cylinder. Furthermore, 4 is a throw-away type drill, and a cutting tip 5 is attached to the tip.

The inclined plate 3 has an outer diameter slightly larger than the outer diameters of the main body 1 and the holder 2, and is provided with cross-shaped knurling 29 around the entire circumference in order to facilitate rotation during dimension adjustment. Also, when the point Q where the thickness of the inclined plate 3 is the smallest and the outer cutter tip 5 coincide on the rotation center line 11 of the main body 1, the tip 5 is at the farthest position from the rotation center line 11 of the main body 1, so the machining dimension is maximum. As the inclined plate 3 is rotated from this position, the cutting edge 5 passes along a nearly circular curve and approaches the rotation center line 11 one after another, reaching a distance of half the nominal outside diameter of the drill at about 90 degrees, and continues to approach from then on. When it is continuously rotated 180 degrees, it will be closest and the machining dimensions will be the smallest. Conversely, when the thickest point of the inclined plate 3 and the cutting edge 5 coincide on the rotation center line, the machining dimension becomes the minimum. A base line 32 is engraved on the outer periphery of the inclined plate, and the amount of adjustment is indicated by this and a scale provided on the holding cylinder 2.

This ratio can be expressed as follows. The angle of inclination of the inclined plate 3: β, the radius of the tool: γ, the perpendicular line drawn from the cutting edge 5 to the center line 22 of the drill from the intersection P of the inclined surface of the inclined plate 3 and the rotation center line 11 is the center line 22 of the drill. Distance to intersection point S: l, inclined plate 3
The point where the thickness is the smallest and the outer cutter tip 5 is
The distance between the cutting edge 5 and the rotation center line 11, that is, the machining radius R, is expressed by the following equation, when the angle of rotation of the inclined plate 3 is θ, starting from a position that coincides with the rotation center line.

X=γ+CoSθ{lSinβ−γCosθ(1−Cosβ)} y=Sinθ{lSinβ−γCosθ(1−CoSβ)} R=√ ² + ^2As can be seen from the above equation, the increase or decrease in the machining radius R depends on the slope of the inclined plate 3. Since it is not proportional to the rotation angle, if you want to obtain an equal amount of increase or decrease by turning one scale, you can divide the scale 26 into unequal parts based on the calculated value.

The relationship between the base line 32 provided on the outer periphery of the inclined plate 3 and the scale 26 provided on the outer periphery of the grip tube 2 is adjusted to (+) and (-) around the nominal size of the drill in the embodiment. Base line 32 is placed at the point where the thickness of
When the base line 32 and the cutting edge 5 coincide on the rotation center line 11, the point on the outer periphery of the gripping cylinder 2 that coincides with the base line 32 is the (+) maximum value, and the position 180° opposite from that point is the (-) maximum value. It is as follows. In the example, the "0" position at which the nominal size of the tool can be machined was a position rotated by 90°16' from the (+) maximum position.

(Effects of the Invention) As described above, the tool holder according to the present invention allows easy adjustment of machining dimensions by loosening the bolts 30 and rotating the inclined plate 3 without tools, and has excellent rigidity due to its simple structure. .

In addition, by aligning the scale on the grip cylinder or main body with the base line on the inclined plate, the required dimensions can be quantitatively adjusted almost steplessly while the tool remains attached to the machine without removing the tool. Furthermore, the positioning pin allows the holding cylinder 2 and the main body 1 to be firmly integrated against rotational torque, and there are many advantages such as there being no need to tighten the bolts 30 particularly strongly.

[Brief explanation of the drawing]

Figures 1 and 2 are schematic diagrams of the conventional product, Figure 3 is a partial longitudinal cross-sectional view of the tool holder according to the embodiment of the present invention with the tool attached, and Figure 4 is the one shown in Figure 3 with the tool removed. FIG. 1... Main body, 2... Gripping tube, 3... Inclined plate, 4
... Drill, 5 ... Cutting edge, 6 ... Tool holder shank, 7 ... Inner diameter surface, 8 ... Holder inner surface, 9 ...
Base circle outer circumference, 10... Side wall (opposite end surface) of base circle outer circumference, 11... Rotation center line, 12... Drill shank, 13... Holder side end surface of main body, 14... Relief hole, 15... Screw Hole, 16...Positioning pin, 17...Pin driving hole, 18...Mounting hole, 1
9...Drill mounting bolt, 20...Screw hole, 2
1...Holder end face (opposite end face), 22...Mounting hole center line, 23...Opposite end face, 24...Bolt hole, 25...Elongated hole, 26...Scale, 27...Body side end face, 28... ...Holder side end surface of inclined plate, 29
...Crisscross knurling, 30...Bolt, 31...
...Counterbored hole, 32...Baseline, P...Intersection of slope and center of rotation.

Claims (1)

[Claims] 1. A holder that mounts a tool that cuts the maximum dimension of a workpiece with a single cutting blade, which combines a gripping tube to which the tool is attached and a main body to be attached to a machine, with the opposing end surfaces of the gripping tube and the main body aligned with their respective center lines. an inclined plate formed with a plane perpendicular to the axis, one side of which is a plane perpendicular to the axis, and the other side of which is an inclined plane, is rotatably inserted between the opposing end faces; A tool holder characterized in that the end face of the main body and the end face of the grip cylinder are brought into contact with each other, and a base line is provided on the outer periphery of the inclined needle plate, and a scale is provided on the outer periphery of either the main body or the grip cylinder.