JPS6346164Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a clamping mechanism for a pin-type throw-away tip.

As an example of such a clamping mechanism for a throw-away tip, the U.S. Pat.
There is one disclosed in No. 105244. As shown in FIG. 1, this clamp mechanism is provided with a chip seat 2 at the tip of a tool body 1, which is made up of a chip seat bottom surface 2a and a chip seat wall surface 2b.
A chip 3 is placed on the seat 4 via a sheet 4 and clamped with a pin 5. And the tip seat bottom surface 2a
A screw hole 6 into which a pin 5 is screwed is formed. This screw hole 6 has a structure in which a tapered hole 7 and a counterbore hole 8 are overlapped at the part that opens into the bottom surface 2a of the chip seat, and this overlapping part has a part that protrudes inwardly from the screw hole 6. Two tapered twill lines 9,
9 is formed. Then, insert pin 5 into screw hole 6.
When the pin 5 is screwed in, the intermediate portion 5a of the pin 5 comes into contact with the two tapered twill lines 9, 9.
The head 5b of the pin 5 pushes against the inner wall of the round hole 3a of the chip 3, whereby the chip 3 is pressed and fixed to the chip seat wall 2b. In such a clamp mechanism, pin 5
The screw hole 6 has the feature that a stable clamping condition can be maintained because the two points are in contact with each other.
The pin 5 must be concentric with the taper hole 7, and the dimensions of these parts must be strictly controlled, or the shapes of the screw hole 6, taper hole 7, and counterbore hole 8 are complicated and machining is troublesome. There are also problems in that the shape is complicated and processing is troublesome.

A clamping mechanism as shown in FIG. 2 is also used. This clamp mechanism
A hole 10 perpendicular to this is formed in the bottom surface 2a of the tip seat, a clamp pin 11 with a slightly bulged middle part is inserted into this hole 10, and another screw hole 12 perpendicular to the hole 10 is formed in the tool body 1. Install a clamp screw 1 near the bottom of the screw hole 12 as shown in Figure 3.
Screw on 3. This clamp screw 13 has a cylindrical shape with an intermediate portion 13a eccentric to the screw main body portion 13b. When the clamp screw 13 is rotated, the eccentric intermediate portion 13a connects the lower end 11a of the clamp pin 11 to the chip seat wall surface 2b.
The head 11b of the clamp pin 11 is tilted toward the tip seat wall surface 2b with the intermediate portion thereof as a fulcrum, and the tip 3 is pressed and fixed to the tip seat wall surface 2b. However, this clamp mechanism also has the disadvantages of a complicated shape and mechanism, troublesome machining, a large number of parts, and high cost.

This invention was made in view of the above circumstances, and the purpose is to provide a clamping mechanism for a throw-away tip that has a simple structure, a small number of parts, is easy to manufacture, and can reduce costs. .

This invention will be described in detail below with reference to the drawings.

4 to 6 show an example of a clamping mechanism for a throw-away tip according to this invention, and reference numeral 21 in the figures indicates a tool body. At the tip of this tool body 21, there is a chip seat 22 as in the conventional example.
The chip seat 22 has a flat chip seat bottom surface 22a and a chip seat wall surface 22 that stands up from the flat chip seat bottom surface 22a.
It is composed of b. A screw hole 23 is perpendicular to the tip seat bottom surface 22a and penetrates to the bottom surface 21a of the tool body 21.

This screw hole 23 is located on the bottom surface 21a of the tool body 21.
An incompletely threaded portion 23a is formed from any nearby portion. Moreover, two cavities are formed in the screw hole 23. First, the first cavity 24 is provided on the chip seat bottom surface 22a side and is open to this bottom surface 22a, and has an axis parallel to the axis of the screw hole 23 and It has a diameter larger than the diameter and is eccentric to the chip seat wall surface 22b side,
It is formed as a counterbore hole whose inner periphery is in contact with the inner periphery of the screw hole 23. The depth of this counterbore hole is approximately 1/3 of the total depth of the screw hole 23. The second cavity 25 is provided on the bottom 21a side of the tool body 21 so as to be open to the bottom 21a, is eccentric to the opposite side of the chip seat wall 22b, and has a depth of about 2/3 of the screw hole 23. It is similar to the first cavity 24 except that it is of a certain degree.

Then, the first cavity 24 of the screw hole 23 and the second
The portion sandwiched between the hollow portion 25 and the hollow portion 25 is a fully threaded portion 23b having an effective number of threads of 1 to 3. The optimum number of effective screw threads for this fully threaded portion 23b is two; if it is less than one thread, the threading strength of the clamp screw to be removed later will be insufficient, resulting in a lack of clamping force for the chip; If the clamp screw goes over a mountain, the inclination of the clamp screw will not be sufficient, resulting in a lack of clamping force.

The clamp screw 26 screwed into the screw hole 23 has a head 26a that fits into the hole 27a of the chip 27, an intermediate screw portion 26b that continues from the head 26a and has a larger diameter than the head, and Continuing from this intermediate screw portion 26b, there is a screw hole 2 with a slightly larger diameter than this.
The leg threaded part 26c is screwed into the fully threaded part 23b of No. 3.
It is composed of.

In the clamping mechanism configured as described above, in order to clamp the chip 27, the sheet 28 is first placed on the chip seat bottom surface 22a. (There are cases where the sheet 28 is not used, and in this case, this step is of course unnecessary.) Next, the clamp screw 26
into screw hole 23. Then, the head 26a of the clamp screw 26 is fitted into the hole 27a of the chip 27, and the chip 27 is placed on the sheet 28. When the clamp screw 26 is further screwed in, the clamp screw 2
The tip of the leg screw portion 26c of No. 6 hits the incomplete screw portion 23a of the screw hole 23. When the clamp pin 26 is further screwed in from this state, the incompletely threaded portion 23a
With the fully threaded portion 23b as the center, the head 26a is aligned with the inclination of the tip seat wall surface 22b,
The leg screw portion 26c is tilted to the opposite side of the chip seat wall surface 22b. Due to this movement, the head 26a of the clamp screw 26 presses the inner wall of the hole 27a of the tip 27 against the tip seat wall surface 22b, and the tip 27 is pressed and fixed to the tip seat wall surface 22b and clamped to the tool body 21.

In such a clamp mechanism, the tip portion of the clamp screw 26 contacts the incompletely threaded portion 23a of the screw hole 23, and the intermediate portion contacts the fully threaded portion 23a of the screw hole 23.
b, the clamp screw 26 is firmly fixed, and the chip 27 can always be stably clamped to the tool body 21. In addition, first and second counterbore-shaped cavities 24 and 25 are eccentrically formed in the screw hole 23 having the incompletely threaded portion 23a and the fully threaded portion 23b, and the chip 27 is formed in the positional relationship between them. Since it is clamped, the structure is extremely simple, and the hollow parts 24 and 25
Since it is eccentric to the screw hole 23, a slight error is allowed during machining, and machining becomes easy. moreover,
The clamp screw 26 also has a simple shape and is easy to manufacture.

Furthermore, both FIGS. 7 and 8 show other embodiments of the clamp mechanism of this invention, and the same components as those shown in FIGS. 4 to 6 are designated by the same reference numerals. The explanation will be omitted. In the example shown in FIG. 7, a flange portion 26d is provided on the intermediate threaded portion 26b of the clamp screw 26, and the lower edge of the flange portion 26d presses against the sheet 4 to prevent the sheet 4 from falling. The example shown in FIG. 8 is a case where the hole 27a of the tip 27 has a conical shape whose diameter is enlarged toward the surface side of the tool body 21, and the clamp pin 2
The head portion 26a of No. 6 also has a conical shape.

In the above embodiments, the first and second cavities 24 and 25 were formed by boring counterbore holes eccentric to the screw hole 23.
The clamp screw 26 is not limited to this, but any shape may be used as long as it has a width equal to or larger than the diameter of the screw hole 23 and is recessed by several mm from the inner wall of the fully threaded portion 23b, so that the clamp screw 26 can be tilted. It is desirable that this can be done easily.

As explained above, the clamping mechanism for the throw-away tip of this invention has a screw hole with an incompletely threaded portion provided in the chip seat of the tool body, and a screw hole that is biased toward the chip seat wall surface on the chip seat side of the screw hole. 1 cavity and a second cavity that is biased toward the opposite side of the chip seat wall surface on the bottom side of the tool body, and place a clamp screw against the incompletely threaded part and tilt it toward the chip seat wall surface to hold the chip. Since it is designed to be clamped, the chip can always be firmly and stably clamped to the tool body. In addition, compared to conventional clamping mechanisms using taper and eccentricity, the clamp screw concentric with the screw hole that is concentric with the center of the throwaway chip hole escapes into the first and second cavities and is clamped. Since it is a straight line, there is no need for taper or eccentricity at all. Furthermore, the clamping mechanism is extremely simple, which facilitates manufacturing and processing, requires fewer parts, and reduces costs.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing a conventional example, Figs. 2 and 3 show another conventional example, Fig. 2 is a schematic sectional view, and Fig. 3 is a front view of a clamp screw used in this conventional example. , Fig. 4 to Fig. 6 show an example of the clamp mechanism of this invention, Fig. 4 is a schematic sectional view of the state in which the clamp screw is not installed, and Fig.
A bottom view of the same state as shown in the figure, viewed from the bottom of the tool body.
FIG. 6 is a schematic sectional view showing a clamped state with a clamp screw attached, and FIGS. 7 and 8 are both schematic sectional views showing other examples of this invention. 21... Tool body, 21a... Bottom surface, 22...
Chip seat, 22a... Chip seat bottom, 22b...
Chip seat wall surface, 23...screw hole, 23a...incomplete threaded part, 23b...completely threaded part, 24...first
cavity, 25...second cavity, 26...clamp screw, 27...chip, 27a...chip hole.

Claims (1)

[Scope of Claim for Utility Model Registration] A throw-away tip clamp that fixes a perforated tip with a clamp screw to a tip seat at the tip of a tool body that has a flat tip seat bottom surface and a tip seat wall surface that rises from the bottom surface. In the mechanism, a screw hole is provided in the chip seat, which is perpendicular to the bottom surface of the chip seat and is an incompletely threaded portion from an arbitrary depth, and a first cavity is provided on the bottom side of the chip seat of the screw hole and is biased toward the chip seat wall surface. A second cavity is provided on the bottom side of the tool body of this screw hole, which is biased toward the opposite side of the chip seat wall surface, and an effective number of threads is 1 to 3 between the first and second cavity. 1. A clamp mechanism for a throw-away chip, characterized in that one end of the clamp screw is fitted into a hole in the chip, and the other end is screwed into the screw hole, leaving a fully threaded part.