JPS5810167B2 - Cutting tool holder lock nut stopper mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stopper mechanism for preventing loosening of a lock nut of a holder used for gripping a cutting tool such as a drill, reamer, or tap.

This cutting tool holder is designed to simplify the structure, increase holding power, and reduce costs by omitting the conventional split collet and allowing the tool to be directly gripped by the holder body. This was previously proposed by the inventor (Japanese Patent Application No. 55-109931).

This holder consists of a main body with a grip formed at the tip, a lock nut attached to its outer periphery via a ball bearing, and a thrust ring interposed between the grip and the lock nut and supported by the lock nut via a ball screw mechanism. consists of rotating the lock nut in place,
The thrust ring that compresses the grip is moved up and down.

However, as mentioned earlier, when a ball is interposed between the lock nut and the thrust ring, and between the main body and the lock nut, the ball is compressed when the lock nut is tightened, and its restoring force reduces frictional resistance, making it easier to rotate the lock nut. This causes problems such as tightened lock nuts becoming loose and tools falling off.

The present invention was proposed in order to solve the above problems, and an object of the present invention is to provide a stopper mechanism that can securely fix a lock nut.

Hereinafter, the configuration of the present invention will be explained based on the attached FIGS. 1 and 2.

FIG. 1 shows a holder that employs the stopper mechanism of the present invention, and a gripping portion 3 that directly grips the shank S of a cutting tool inserted into the center hole 2 is provided at the tip of the holder body 1. The thrust ring 4 is fitted around the outer periphery of the thrust ring 4.

Further, the thrust ring 4 is attached to a lock nut 6 attached to the outer periphery of the main body 1 via a ball 5 so as to rotate at a fixed position.
The gripping portion 2 is compressed and released by moving the thrust ring 4 up and down in accordance with forward and reverse rotation of the lock nut.

The stopper mechanism 10 of the present invention is provided between the lock nut 6 and a flange 8 formed on the outer periphery of the holder body.

That is, a jam nut 11 that contacts the upper surface of the lock nut 6 is screwed onto the outer periphery of the holder body 1, and is attached to the jam nut 11, as shown in FIG.
Elastic bodies 13, such as wire springs, are attached to stopper pins 12 whose other ends protrude from the lower part of the flange 8 of the holder body.

The jam nut 11 is configured to move upward when it is rotated in the lock nut tightening direction, and a plurality of grooves 14 (see Fig. 2) for locking a hook spanner are provided on the outer periphery of the jam nut 11. .

Further, the elastic body 13 is installed in advance by being compressed in the tightening direction of the lock nut, and its restoring force causes the jam nut 1 to tighten.
1 is pushed in the direction of downward movement (in the direction of the arrow in FIG. 2) and is in pressure contact with the upper surface of the lock nut 6.

In the embodiment shown in the figure, a circumferential groove 15 is provided on the upper surface of the jam nut 11 and the elastic body 13 is housed therein, but this elastic body may be provided outside the jam nut. The other end may omit the stopper pin 12 and be directly engaged with the main body 1.

The stopper mechanism of the present invention is as described above, and its operation will be described below.

In FIG. 1, when the lock nut 5 is rotated to the left when viewed from above, the thrust ring 3 slides upward and the grip part 2
gradually compress.

At this time, the lock nut 6 rotates at a fixed position, while the jam nut 11 pressed against the upper surface of the nut 6 rotates together with the nut 6 due to the frictional resistance of the contact portion 16 with the lock nut and moves slightly upward.

Therefore, the frictional resistance of the abutting portion 16 is reduced, causing the jam nut 11 and the lock nut 6 to slip against each other, and thereafter only the lock nut rotates to continue tightening.

Next, when tightening is completed and the rotation of the lock nut is stopped, the jam nut 11 is tightened by the restoring force of the elastic body 13, which has been compressed in advance and is further compressed when the lock nut is tightened.
is reversed and pressed against the upper surface of the lock nut 6.

Therefore, after tightening is completed, the nut 6 is fixed by the frictional resistance of the abutting portion and is prevented from loosening.

When removing the cutting tool, use a wrench or the like to rotate the jam nut in the upward direction to release the contact at the abutment portion 15, and the lock nut can be loosened with a force as small as that which can be turned by hand.

As explained above, according to the stopper mechanism of the present invention,
Loosening of the lock nut is reliably prevented, and problems such as the cutting tool falling off are eliminated.

In addition, although the holder described here has a grip part formed integrally with the main body, the stopper mechanism of the present invention is also applicable to a holder that uses a split collet in place of the grip part.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a holder employing the stopper mechanism of the present invention, and FIG. 2 is a sectional view taken along the line A-A of the same. 1... Holder body, 3... Gripping part, 4
... Thrust ring, 6 ... Lock nut, 7 ... Ball screw mechanism, 10 ...
・Stopper mechanism, 11... Jam nut, 13
...Elastic body.

Claims (1)

[Claims] 1 By rotating the lock nut attached to the outer periphery of the holder body in a fixed position, the thrust ring supported by the lock nut is slid upward via a ball screw mechanism, and the grip part formed integrally with the holder body or the center of the body In a cutting tool holder that compresses a split collet inserted into a hole, a jam nut that moves upward when rotated in the tightening direction of the lock nut is attached to the outer periphery of the holder body by screw engagement, and one end is attached to the outer periphery of the holder body. A lock nut characterized in that an elastic body is attached to the jam nut, the other end of which is locked to the holder body, and the elastic body is compressed in advance in the tightening direction of the lock nut, and its restoring force presses the jam nut against the upper surface of the lock nut. stopper mechanism.