JPH10100006A - Clamp bite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the shaking vibration in the transverse direction by forming a tapered surface of a lower root body part of a pin, forming a curved projected surface on a part to be abutted on the tapered surface in a center hole of a cutting insert, and pressing the tapered part and the curved projected surface against each other in an exceedingly small area in an approximately point contact manner. SOLUTION: A part from a pin 6b to a stopper part 6c on the lower side of a pin member 6 is tapered, and a tapered surface 6e is provided on a root part of the pin 6b. A curved projected surface 3b is formed on a part engaged with the pin 6b of a center hole 3a of an insert 3, and the curved projected surface and the tapered surface are pressed against each other with an extremely small area so that the pin 6b is brought into approximately point contact with a hole wall of the center hole 3. Because no stress is distributed in this pressed condition, a tip can be effectively restricted in the prescribed direction, and in particular, the effect to prevent the shaking vibration in the transverse direction is remarkable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp tool for detachably fixing a cutting insert for processing a metal material or the like to a tip portion of a holder.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conventional clamping tool includes a cutting insert (hereinafter simply referred to as an insert) A.
Has been mainly used, or a method in which the insert A is pressed from above by an upper clamper D as shown in FIG.

However, the clamp bit by the clamp screw C has a small restraining force of the insert A,
Further, when the insert A is replaced, the clamp screw C must be completely removed, and it takes time, so that there is a problem that the working efficiency is deteriorated.
Further, at the time of the replacement, the screw C may be lost.

[0004] Next, the clamping tool using the top clamper D has a larger restraining force than the one using the clamp screw C. However, in the case of internal diameter machining, chips hit the clamper D protruding to the outside, which hinders discharge. In some cases, this could cause chip intrusion or damage to the machined surface.

On the other hand, Japanese Utility Model Publication No. Sho 50-29190 shows another type of clamp tool, in which a pin member having a pin at the tip is screwed to the tip of the holder.
This pin presses the hole wall of the center hole of the cutting insert and clamps the insert.It has a structure that does not easily cause problems such as loss of parts or chip entrapment like the above-mentioned clamp tool. I was

[0006]

2. Description of the Related Art However, the above prior arts include:
There were the following problems.

That is, in the clamp tool using the above-mentioned pin member, the force for attracting the insert to the holder side is also weak, and the contact between the pin and the insert becomes surface or line contact and the stress is dispersed. Blurred vibration is likely to occur, which may affect the finish of the machined surface.

[0008]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the present invention provides
An object of the present invention is to provide a clamp bite which is less likely to lose parts, cause problems such as chip intrusion, and is less likely to generate lateral vibration, and has a good finished surface.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention relates to a pin lock type clamping tool, wherein a tapered surface is formed at a lower root portion of a pin, and a center hole of the cutting insert is formed. In (2), a curved convex surface is formed at a portion that comes into contact with the tapered surface, and the two are pressed against each other with an extremely small area such as almost point contact.

[0010]

According to the clamp bite of the present invention, as shown in FIG. 1, a pin member 6 is fitted into a pocket 5 penetrating through an insert seat portion 4 at the tip end of a holder, and the pin 6b is used to form a central hole 3a of the insert 3. This is a pin lock system in which the insert 3 is fixed to the insert seat portion 4 of the holder 2 by pressing the hole wall, so that problems such as loss of parts and biting of chips hardly occur.

Further, as shown in FIG.
Of the insert 3 has a curved convex surface 3b at a position where the pin 6b of the center hole 3a engages with the pin 6b, so that the pin 6b and the hole wall of the center hole 3 are substantially in point contact. Pressing is performed in an extremely small area as shown in FIG. That is, since the stress does not disperse in such a pressing state, the insert can be effectively restrained in a specific direction, and particularly, the vibration in the lateral direction is prevented.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a clamp bit 1 for machining an inner diameter according to the present invention. The clamp bit 1 is provided with a recessed insert seat 4 on which an insert 3 is placed at a tip end portion of a holder 2. The pocket 5 is recessed. A pin member 6 provided with a pin 6b on the distal end side is fitted and fixed in the pocket 5, and the pin 6b presses the hole wall of the center hole 3a of the insert 3 to insert the insert 3 into the insert seat of the holder 2. It is adapted to be fixed to the part 4.

The pin member 6 comprises an annular portion 6a for fitting with the fixing bolt B and a tall stopper portion 6c for connecting a pin 6b projecting forward. The fixing bolt B is screwed into the bolt hole N formed in the bottom surface 5a of the pocket 5 through the formed bolt insertion hole 6d, and the pin member 6 is
It is designed to be fixed inside.

The pocket 5 has a narrow groove 5b at a portion connected to the insert seat portion 4, so that the side surface of the pin member 6 comes into contact with the groove wall surface of the narrow groove 5b. The lateral displacement of the member 6 is prevented.

FIGS. 2 and 3 are sectional views taken along the line X--X in FIG.
Shows a state before fixing is performed. As shown in FIG. 2, when the fixing bolt B is loosened, the pin 6b
Is in the upper position and can be relatively freely fitted into the center hole 3a of the insert 3, but when the fixing bolt B is screwed in as shown in FIG. 3, the pin 6b is lowered. The hole wall of the central hole 3a of the insert 3 is pressed.
As shown in the drawing, the pin member 6 is tapered from the lower pin 6b to the stopper portion 6c. As shown in the bottom view of FIG. 4, a tapered surface 6e is formed at the root of the pin b. Is provided. On the other hand, a portion of the center hole 3a of the insert 3 which engages with the pin 6b has a curved convex surface 3b.
And the pin 6b and the hole wall of the central hole 3 are pressed against each other with an extremely small area such as almost point contact. In other words, since the stress does not disperse in such a pressing state, the chip can be effectively restrained in a specific direction, and the effect of preventing vibration in the lateral direction is particularly great.

Further, since the pin 6b is provided below the annular portion 6a, the distance between the fulcrum T and the operating point F with respect to the force from the fixing bolt B can be increased, so that a large stress is applied to the operating point. F and the pin 6
Since b is taperedly engaged with the insert 3 by the curved tapered surface 6e, not only the downward direction but also a force for pulling the insert to the rear of the holder 2 acts greatly.

Further, depending on the direction in which the stopper portion 6c of the pin member 6 is taller, a restraining surface against the lateral movement of the pin member 6 is increased, thereby preventing not only lateral displacement but also lateral chatter. doing.

The present invention is not limited to the above embodiment, and it goes without saying that various forms can be adopted without departing from the object of the invention.

[0019]

As described above, according to the present invention, in a pin lock type clamping tool, a tapered surface is formed at a lower root portion of a pin, and the tapered surface comes into contact with a center hole of the cutting insert. By forming a curved convex surface at the part and pressing them with an extremely small area such as almost point contact, stress does not disperse, so the chip can be effectively restrained in a specific direction, especially in the lateral direction. Vibration can be prevented.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a clamp tool according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG. 1, showing a state before the insert is clamped.

FIG. 3 is a sectional view taken along line XX of FIG. 1, showing a state where an insert is clamped.

FIG. 4 is a bottom view of a pin member constituting the clamp bite of FIG. 1;

FIG. 5 is a perspective view of a conventional clamp bit by a clamp screw.

FIG. 6 is a perspective view of a conventional clamp bite using a top clamper.

[Explanation of symbols]

 B Fixing bolt N Bolt hole T Support point F Applied point 1 Clamp tool 2 Holder 3 Cutting insert 3a Central hole 3b Curved convex surface 4 Insert seat 5 Pocket 5a Bottom surface 5b Narrow groove 6 Pin member 6a Annular portion 6b Pin 6c Stopper portion 6d Bolt insertion hole 6e Tapered surface

Claims (1)

[Claims] 1. A pocket formed at a tip portion of a holder,
A clamp bit that fits a pin member having a pin on the tip side and clamps the cutting insert to the holder by pressing the hole wall of the central hole of the cutting insert with the pin, and at a lower root portion of the pin. A clamp bite configured to allow a curved convex surface formed in a central hole of the cutting insert to abut against the formed tapered surface.