JPH0230180Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is a cutter attachment device that is attached to the main shaft of a machine tool and detachably holds a cutter for milling, and is particularly suitable for holding large diameter cutters. This invention relates to a cutter attachment device.

[Conventional technology and its problems]

The ease with which a cutter can be attached to and removed from a machine tool has a large effect on the operating rate of the machine. For this reason, a number of so-called quick change type cutter attachment devices have been proposed, which are attached to the main shaft of a machine tool and hold the cutter in a manner that allows it to be attached and detached with a simple operation. A typical example is a mounting device that uses a petal-shaped clamper attached to the shaft of the main body to tighten the front center of the cutter and press the back of the cutter against the front seating surface of the main body.

However, although this type of device is suitable for holding small-diameter cutters, it is not suitable for holding large-diameter cutters, such as those exceeding φ200. This is because stable holding force can only be obtained by applying uniform clamping force to the entire back surface of the cutter, but in order to meet this requirement, a small clamper would not be able to tighten the outer periphery completely, so it is proportional to the diameter of the cutter. This is because the diameter of the clamper must be increased, which reduces the rigidity of the cutter through which the clamper is inserted.

In addition, with conventional devices, the clamping force acting on the cutter is equal to the wrench torque applied to the clamper's tightening parts, or is only slightly amplified by the taper piece, etc. One of the reasons is that it is difficult to obtain a large clamping force as almost all of the required clamping force must be generated.
It is mentioned as one of the

On the other hand, this can also be called a quick change tool attachment device, and it is a daruma hole type cutter, in which a long hole in the circumferential direction (daruma hole) with a large diameter at one end and a small diameter at the other end is placed in the same direction on a concentric circle as the axis. Adapters used to hold a plurality of cutters are also well known. This adapter is designed so that the head of the cap screw screwed onto the front surface corresponding to the Daruma hole of the cutter is inserted from the large diameter part of the hole, and engaged with the edge of the small diameter part by relative rotation with the cutter. Since the clamping point is far from the central axis, it is suitable for holding large-diameter cutters, and has the advantage that the cutter can be attached and detached without removing the cap screw.

However, since it is necessary to loosen and tighten all of the plurality of cap screws, it is not as superior in workability when attaching and detaching the cutter as compared to the former device.

Therefore, this invention attempts to provide a cutter attachment device that takes advantage of only the advantages of the two cutters mentioned above.

[Means for solving problems]

The cutter attachment device of this invention which solves the above problems generates thrust in the clamping direction by the restoring force of the elastic body, and generates thrust in the opposite direction by the thrust of the operating screw screwed into the shaft center of the main body. An inner piece is provided in the center hole of the body, which is generated by the restoring force of an elastic body with a force smaller than that of the above-mentioned elastic body or by the weight of the clamper. A plurality of clampers that lock the protruding head to the small diameter edge of the Daruma hole are provided at regular pitches in the circumferential direction, and the lever is engaged with the load point to the clamper, the force point to the inner piece, and the fulcrum to the main body. It is characterized in that the clamping force due to the restoring force of the elastic body is transmitted to the clamper through the clamper, and the cutter is tightened by retracting the clamper.

In other words, by linking multiple clampers with the movement of one operation screw, workability when attaching and removing the cutter is improved, and the clamper is located away from the center of the main body, and the transmission is transmitted to the clamper. By amplifying the force exerted by the lever, a uniform clamping force is applied to the entire back surface of the cutter, and a large clamping force is generated with a small wrench torque.The above effects enable quick attachment and detachment and stability even with large diameter cutters. This idea made it possible to maintain this level.

〔Example〕

An embodiment of this invention is shown in the attached drawings.

Reference numeral 1 in the figure is the main body, and this main body includes a positioning reference boss 2 concentric with the cutter center axis that brings the outer peripheral surface into close contact with the inner surface of the center hole of the cutter A, and a seat surface perpendicular to the center axis that presses the back surface of the cutter A. 3. A plurality of axial clamper insertion holes 4 with one end open on the seat surface.
A through hole 6 extending from each hole 4 to a center hole 5 of the main body, a bolt hole 7 for fixing the main body to a spindle of a machine tool, and a key groove 8 for engaging a torque transmission key of the spindle are provided. Although a plate 9 that closes the opening of the center hole is bolted to the tip of the boss 2, this plate may be formed integrally with the main body. Moreover, although the outer peripheral surface of the boss 2 is preferably a tapered surface, it may be a straight surface.

A spanner insertion hole 10 is provided in the center of the plate 9.
An operating screw 11 with an exposed portion is screwed together. Inside the center hole 5 of the main body, there is an arbor 12 whose tip is in contact with the end surface of the screw 11, and an inner piece 14 which is loosely fitted onto the arbor and whose back surface is engaged with the rear large diameter portion 13 of the arbor. A disc spring 17 is installed between a seat plate 15 fixed to the tip of the arbor and a small diameter portion 16 of the center hole of the main body to bias the arbor forward. Note that the inner piece 14 is provided with a hole 18 having a narrow opening at a position corresponding to the through hole 6.

On the other hand, in the clamper insertion hole 4, a clamper 21 having an outer diameter smaller than the large diameter part of the Daruma hole of the cutter and larger than the small diameter part and a hole 20 corresponding to the through hole 6 is inserted. It is slidably inserted so as to protrude from the seat surface 3 by a predetermined amount. Also,
Inside the through hole 6, a lever 25 having a spherical force point 22, a fulcrum 23, and a load point 24 is installed. They are respectively engaged and incorporated into the inner surfaces of the holes 20.

In addition, near the operation part of the operation screw 11, in order to prevent the screw from over-rotating, there is a rotation control mechanism for the operation screw, which consists of an imperfectly circular groove 25 provided on the outer periphery of the screw and a stopper 26 screwed to the plate 9. Although a quantity regulating means is provided, this can be omitted.

Further, at least two clampers 21 are required. However, in order to make the clamping force more stable, it is desirable to provide three or more.

Furthermore, the direction of the lever 25 is not limited to the radial direction of the main body. For example, if it is oriented in the tangential direction of the inner piece, the distance from the fulcrum to the point of effort can be increased, increasing the boost ratio.

In addition, in order to apply centripetal force to the inner piece 14, it is preferable that the piece and the large diameter portion of the arbor 12 make spherical contact as shown in the figure. In addition, in the device shown in the figure, the arbor 12 and the inner piece 14 are connected by a bolt 28 via a disc spring 27, and the thrust in the loosening direction of the screw 11 is transmitted to the clamper 21. However, the movement of the clamper in the loosening direction This may be achieved by interposing an elastic body with a force smaller than that of the disk spring 17 between the inner piece 14 and the small diameter portion 16, and using the restoring force of the elastic body, or when the device is used in the orientation shown in Fig. 1. If the weight on the clamper side with respect to the fulcrum of the lever 25 is greater than that on the piece 14 side, the clamper will slide in the loosening direction without taking any special measures. Furthermore, if the screw 11 and the arbor 12 are separated as shown in the figure, the rotational resistance of the screw 11 can be reduced, but if the bolt 28 is omitted, the two can be integrated.

Reference numeral 29 indicates a plug screw, which is provided as necessary.

[Effect]

The device according to the embodiment described above inserts the head of the clamper 21 into the large diameter part of the daruma hole of the cutter A, and by relative rotation with the cutter, the head part of the clamper 21 is inserted into the small diameter part of the daruma hole a as shown in FIG. When the operating screw 11 is rotated in the loosening direction after being locked to the edge, the inner piece 14 moves forward due to the restoring force of the disc spring 17, and the clamper 21 sinks into the hole 4 due to the force amplified by the lever 25. The cutter is clamped by being pulled in the direction.
Furthermore, when the screw 11 is reversed, the propulsive force of the screw is transmitted to the clamper, the clamper slides in the opposite direction, and the clamper force is released.

〔effect〕

As explained above, in the cutter attaching device of this invention, since a plurality of clampers are linked to one operation screw, the cutter can be attached and detached easily and quickly.

In addition, since each clamper is located far from the center of the main body, uniform clamping force is applied to the entire back of the cutter.
Moreover, since the spanner torque applied to the operating screw is amplified by the lever and transmitted to the clamper, a large tightening force can be obtained with a small force, and therefore even a large diameter cutter can be stably held.

Furthermore, there is the advantage that existing Daruma hole type cutters can be maintained as they are without any modification.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of the device of this invention, Fig. 2 is a sectional view taken along the line X-X, and Fig. 3 is a sectional view showing an example of the device of this invention.
The figure is a front view. 1...Main body, 2...Mounting reference boss, 3...Seat surface, 4...Clamper insertion hole, 5...Center hole, 6...
...Through hole, 11...Operation screw, 12...Arbor,
14...Inner piece, 15...Seat plate, 16...Small diameter section, 17...Disc spring, 21...Clamper, 25
... lever, 27 ... elastic body, 28 ... bolt.

Claims (1)

[Scope of claim for utility model registration] (1) Installation reference boss concentric with the central axis of the cutter,
It has a seat surface to which the back of the cutter is pressed, one end of which is open to the seat surface, and a clamper insertion hole provided at a fixed pitch around the reference boss, and a through hole that passes through the hole to the center hole, on the opposite side from the seat surface. A main body whose back is fixed to the spindle of a machine tool, an operating screw whose tip end is exposed and screwed into the center of the front of the main body, and one end which is inserted into the center hole of the main body. between the arbor that is connected or in contact with the end face of the operating screw, the inner piece that is loosely fitted onto the arbor and whose back surface is engaged with the rear large diameter part of the arbor, and the seat plate at the tip of the arbor and the main body. An elastic body is compressed to urge the arbor forward, and a head whose outer diameter is smaller than the large diameter part of the circumferential Daruma hole provided in the cutter and larger than the small diameter part protrudes from the seat surface by a predetermined amount. A plurality of clampers are slidably inserted into the clamper insertion holes, and a lever is assembled into the through hole of the main body by engaging the load point with the clamper, the force point with the inner piece, and the fulcrum with the main body. A cutter attachment device consisting of. (2) The cutter attachment device according to claim (1) of the utility model registration, characterized in that a means for regulating the amount of rotation of the operating screw is provided between the main body and the operating screw. (3) Utility model registration claim No. (1) characterized in that the operating screw and the arbor are separated from each other, and the large diameter part of the arbor and the inner piece are connected by a bolt via an elastic body. The cutter attachment device described in paragraph or paragraph (2).