JPH0214888Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a cutter attachment device that is attached to the main shaft of a machine tool to hold a milling cutter or other cutting tool, and more specifically, a cutter attachment device that can quickly attach and detach the cutter. This invention relates to improvements to quick-change type cutter attachment devices.

[Conventional technology]

One of the well-known quick-change type cutter attachment devices is a petal-shaped clamp attached to an adapter, that is, a shank end similar to, but slightly smaller than, the notched grooved hole of the flange provided in the center hole of the cutter body. There is a type that fixes the cutter to the adapter using a clamp that inserts the protruding locking piece (petal) on the outer periphery into the above-mentioned notched grooved hole and engages the front surface of the flange by rotating relative to the cutter body. .

Many of the cutter attachment devices employing such clamps generate the tightening force by the propulsive force of a manually rotated screw or cam, but these devices are difficult to obtain strong tightening force and are difficult to tighten. The problem is that the force varies, and the holding state of the cutter tends to become unstable. Therefore, a device that stabilized the tightening force by using the elastic force of an elastic body was developed in 1972.
150416, etc. This is the device shown in FIG. In this figure, reference numeral 1 is an adapter bolted to the main axis A of the machine tool, 2 is a petal-shaped clamp attached to the center of the tip so as not to rotate, 3 is a disc spring that urges the clamp 2 backward,
4 is a hydraulic pressure supply pipe, and 5 is a pusher that moves the clamp 2 forward.The cutter body B is tightened by pulling the clamp 2 backward by the force of the disc spring 3, and pressing the back of the cutter against the seat surface at the front of the adapter. This is done by bringing them into pressure contact, while releasing the tightening is done by applying hydraulic pressure to the pusher 5.

[Problem that the invention attempts to solve]

However, the above-mentioned device that releases the clamp using hydraulic pressure requires an electric circuit and a hydraulic pressure generating device on the machine side to operate the pusher by operating a switch, and the main shaft of the machine tool also requires a hydraulic system including a rotary joint. A pressure supply path must be provided,
Therefore, there were problems in that the cost was high and the overall size of the device was increased.

For this reason, Utility Model No. 59-109435, Utility Model No. 58-
Holding devices such as those shown in each publication of No. 56109 have also been developed, but with the former, the cutter is unclamped only when the eccentric cam is operated.
It is necessary to operate the eccentric cam with one hand while attaching and detaching the cutter with the other hand, and the operability is not yet satisfactory. On the other hand, in the latter case, a taper slide piece is used to slide the locking piece against a spring force to generate a clamping force, so that the locking piece tends to loosen during use, making the clamp unstable. Further, since one of the pair of slide pieces cannot rotate, it is difficult to operate it if the rotation stop position of the machine is shifted from the working side.

Therefore, the present invention aims to solve the above-mentioned problems while ensuring good operability and stable tightening force when attaching and detaching the cutter.

[Means for solving problems]

The cutter attachment device of the present invention that achieves the above purpose has a radial through hole in which the openings at both ends are tapered holes in the shaft of a petal-shaped clamp that generates a tightening force using an elastic body. On the other hand, the adapter body with the above-mentioned shaft inserted into the center hole has a radial shaft hole extending from the side to the center hole, slightly eccentric to the front end side with respect to the above-mentioned through-hole, and a 180° symmetrical position. A pair of male and female operation pieces screwed into each other are rotated and slightly inserted into the shaft hole of the adapter main body. It is characterized by the fact that it is inserted into a state where axial movement is permitted.

In the cutter attachment device configured in this way, the cutter is fixed by the force of the elastic body, so that the tightening force is stable. Additionally, when one of the operating pieces is rotated, the pair of pieces approaches due to the propulsive force of the screw, and a force is generated between each piece and the tapered engagement portion of the petal-shaped clamp to move the clamp toward the front end. Since the tightening force of the clamp is released, the cutter can be quickly tightened and removed manually.

〔Example〕

Embodiments of the present invention are shown in FIGS. 1 to 3.

Reference numeral 10 in FIGS. 1 and 2 is an adapter body, and at its front end there is a positioning reference boss 11 that is concentric with the axis of the cutter body 40 and brings the outer peripheral surface into close contact with the inner surface of the center hole of the cutter body. A support seat 12 is formed to press the back surface. In addition, this adapter body has an insertion hole 13 for a fixing bolt to the main shaft of a machine tool, a key groove 14 into which a drive key at the tip of the main shaft is fitted, a center hole 15 that passes through the shaft center, and a hole 15 that extends from the side to the center hole. Two radial shaft holes 16 whose exit positions are changed by 180 degrees and a drive pin 17 that engages with a keyway 41 on the back surface of the cutter body and transmits the rotational force of the adapter to the cutter are provided.

A shaft portion 19 of a petal-shaped clamp 18 is slidably inserted into the center hole 15 of the adapter body. This petal-shaped clamp has a through hole 21 in the middle of the shaft 19 whose openings at both ends are tapered holes 20, and a notch in the flange 42 provided in the center hole of the cutter body at the tip of the shaft. Grooved hole 43
(The boss 11 is in close contact with the inner surface of this hole.) A similar but slightly smaller petal-shaped locking piece 22 (see Fig. 2) is provided to protrude in the radial direction.
Place the locking piece 22 into the hole 4 at a position corresponding to the notch groove.
3, the cutter is rotated relative to the cutter to lock it to the front surface of the flange 42, and then the clamp is moved back to press the back surface of the cutter against the support seat 12. As can be seen from the figure, the clamp 18 is tightened by the elastic force of a disc spring 24 compressed between the ring-shaped seat plate 23 fixed to the rear of the shaft 19 and the adapter body. It is carried out with

On the other hand, to release the tightening, use the pair of male and female operation pieces 2.
This is done by 5,25' rotations. That is, the shaft hole 16 is slightly eccentric toward the front end with respect to the through hole 21, and the shaft hole has a spanner insertion hole 26 at the outer end and a taper hole 20 at the inner end. The aforementioned operating pieces 25, 25' having a tapered shaft portion 27 that engages with the hole 21 are inserted by threading the screw portion 28 of the male piece 25 through the hole 21 into the female thread 29 of the female piece 25', When one of the pieces is rotated by an external force and the pair of pieces approaches each other due to the action of the threaded part, a force P in the direction of the arrow is generated at the tapered engagement part of the clamp of each piece.
This force moves the clamp 18 toward the front end against the force of the disc spring 24 (the amount of movement is small), and the clamping force is released.

Note that excessive rotation of the operating pieces 25, 25' leads to wasted time for changing the cutter, and if one operating piece rotates while the other piece rotates, the paired pieces approach each other.
Therefore, it is desirable to provide such a prevention mechanism in the device of the present invention. In the illustrated device, each piece has an annular stopper insertion groove 30 shown in FIG. A stopper 31 is provided, and the stopper 31 limits the axial movement of the pieces 25, 25' to regulate the amount of rotation of each piece.
3, the piece 2 is moved with a force greater than the frictional force of the threaded part.
5 and 25' to prevent the other piece from rotating together. Rotational resistance may be applied to the operating piece by interposing a rubber ring between it and the adapter body, or even if there is no resistance applying means, it is possible to manually fix one piece when rotating the other piece. This will prevent co-rotation.

In addition, an elastic body other than a disc spring may be used to tighten the clamp, and to prevent the seat plate 23 from loosening, spot welding may be performed at appropriate locations, or a pin or key may be installed between the seat plate 23 and the shaft portion 19. It is desirable to take appropriate measures such as inserting a split ring or using a split ring. Furthermore, the key groove 14, the key and drive pin 17 on the machine tool side, and the key groove 42 of the cutter
Both positions can be reversed.

〔effect〕

In the cutter attachment device of the present invention described above, since the clamp is tightened by the elastic body built into the adapter, a uniform and strong tightening force is always obtained, and the holding state of the cutter is stabilized.

In addition, since the clamp can be tightened and unfastened simply by reversing the operating pieces located at 180° symmetrical positions, the cutter can be replaced easily and quickly without being affected by the rotational stop position of the machine, and of course reduces costs. It also becomes possible to downsize the device and reduce installation space.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of the cutter attachment device of the present invention, Fig. 2 is a front view thereof, Fig. 3 is a sectional view of the engagement part between the operating piece and the stopper, and Fig. 4 is a conventional cutter attachment device. FIG. 2 is a cross-sectional view of the device. 10...Adapter body, 11...Positioning reference boss, 12...Support seat, 15...Center hole, 16...
...Shaft hole, 18...Clamp, 20...Tapered hole,
21... Through hole, 22... Locking piece, 23... Seat plate, 24... Belleville spring, 25, 25'... Operation piece,
27...Tapered shaft portion, 28...Threaded portion, 29...
Female thread, 30...stopper groove, 31...stopper, 33...disc spring.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) An adapter body having a positioning reference boss concentric with the axis of the cutter at the front end and a support seat on the back of the cutter, and the tip of the shaft that is slidably inserted into the center hole of the adapter body. A clamp has a petal-shaped locking piece similar in shape to the grooved hole of the flange provided in the center hole of the cutter body, but slightly smaller than that, protruding in the radial direction, and attached to the shaft of this clamp. In a cutter attachment device that includes an elastic body that is compressed between the seat plate and the adapter body and urges the clamp backward, the shaft of the clamp has a radial penetration with openings at both ends being tapered holes. A hole is provided in the adapter body, and a radial shaft hole extending from the side to the center hole is provided in the adapter body at a 180° symmetrical position with a slight eccentricity toward the front end with respect to the through hole.
Further, a pair of male and female operating pieces, which have an operating section at the outer end and a tapered shaft section at the inner end that engages with a part of the tapered hole, and whose inner ends screw together, are inserted into the shaft hole of the adapter body. The shaft is inserted into a state where rotation and slight movement of the shaft body is permitted, and each of the pair of operation pieces is made rotatable by applying a rotational resistance greater than the frictional force of the threaded portion of both pieces. Katsuta attachment device. (2) The rotational resistance given to each of the above pairs of operating pieces is
The cutter attaching device according to claim (1) of the utility model registration, characterized in that the resistance is generated by press-contacting each piece with a resistance applying means.