JPH0230179Y2 - - 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 in which a petal-shaped clamper attached to the shaft center of the main body is used to tighten the front center of the cutter, and the back surface of the cutter is pressed 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 located 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-mentioned problems, uses the rotation of the operating shaft screwed into the shaft center of the main body to absorb the thrust in the clamping direction, and the thrust in the loosening direction by the restoring force of the elastic body. An inner piece is provided in the center hole of the main body, and on the other hand, a plurality of clampers are installed in the circumferential direction on the seat surface of the main body that supports the back of the cutter to lock the head protruding from the seat surface to the small diameter edge of the Daruma hole. The tightening torque applied to the operating shaft is transmitted to the clamper through a lever that engages the load point with the clamper, the force point with the inner piece, and the fulcrum with the main body, and when the clamper is retracted, the cutter is It is characterized by the fact that it is designed to be tightened.

In other words, by linking multiple clampers with the movement of one operating shaft, workability when attaching and detaching 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 whose outer peripheral surface is brought into close contact with the inner surface of the center hole of the cutter A, and a seat surface perpendicular to the center axis which is brought into pressure contact with 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. Furthermore, although the outer circumferential surface of the boss 2 is preferably a tapered surface, it may be a straight surface.

An operating shaft 10 whose tip is screwed into the center of the plate 9 is provided in the center hole 5 of the main body.
A spanner insertion hole 11 exposed to the outside and an imperfectly circular groove 12 are formed at the tip of this shaft, and a large diameter portion 13 is formed at the rear portion. The operating shaft 10 also has a narrow hole 14 corresponding to the through hole 6.
An inner piece 15 having a rear surface engaged with the large diameter portion of the shaft 10 and a disc spring 16, which is interposed between the plate 9 and urges the piece backward, are loosely fitted onto the outside.

On the other hand, in the clamper insertion hole 4, a clamper 19 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 18 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 23 having a spherical force point 20, a fulcrum 21, and a load point 22 has a lever 23 with the force point 20 on the inner surface of the hole 14 of the inner piece, the fulcrum 21 on the inner surface of the through hole 6, and the load point 22 on the clamper. The holes 18 are respectively engaged with and incorporated into the inner surfaces of the holes 18.

Note that the groove 12 of the operating shaft is formed by locking stoppers 24 screwed to the plate 9 at both ends of the shaft 10.
Although the rotation amount regulating means of the operating shaft is provided for the purpose of preventing excessive rotation of the operating shaft, it is not an essential requirement of the present invention.

Further, it is sufficient that the number of clampers 19 is at least two. However, in order to make the clamping force more stable, it is desirable to provide three or more.

Furthermore, the direction of the lever 23 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, the large diameter part of the operating shaft 10 and the inner piece 1
5 is preferably in spherical contact as shown in the figure. This is because the centripetal force of the inner piece is generated at the contact portion.
Reference numeral 25 indicates a plug screw, which is provided as necessary.

[Effect]

In the apparatus of the embodiment as described above, the head of the clamper 19 is inserted into the large diameter part of the daruma hole of the cutter A, and by relative rotation with the cutter, the small diameter part of the daruma hole a is fixed as shown in FIG. An inner piece 15 that rotates the operating shaft 10 in the tightening direction after being locked to the edge.
moves forward while compressing the disc spring 16, and the lever 2
The clamper 19 is pulled in the direction of sinking into the hole 4 by the force amplified by 3, and the cutter is clamped. Also, if the operating shaft 10 is reversed, the disc spring 16
The restoring force causes the clamper to slide in the opposite direction and the clamping force is released.

〔effect〕

As explained above, in the cutter attaching device of this invention, since a plurality of clampers are linked to one operating shaft, 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, a uniform tightening force is applied to the entire back surface of the cutter, and the wrench torque applied to the operating shaft is amplified by the lever and transmitted to the clamper, so a small force is required. A large tightening force can be obtained, so even large-diameter cutters can be stably held.

Another advantage is that the existing Daruma hole type cutter can be retained as is.

[Brief explanation of drawings]

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, 10...operation shaft, 15...inner piece, 16...disc spring, 19...clamper, 23...
…lever.

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 that presses the back of the cutter, a clamper insertion hole with one end open to the seat surface and provided at a fixed pitch around the reference boss, and a through hole that passes from the hole to the center hole, and the opposite side from the seat surface. The main body is fixed to the spindle of the machine tool by preventing rotation, the operating shaft has an operating part at the tip exposed and is screwed into the center shaft of the main body, and the main body has a main body that is screwed into the center shaft of the main body with the operating part exposed. An inner piece that is fitted externally and has its back surface engaged with the rear large diameter part of the operating shaft, an elastic body that is interposed between the main body and urges this piece backward, and a circumference whose outer diameter is provided in the cutter. A plurality of clampers whose heads are smaller than the large diameter part of the Daruma hole and larger than the small diameter part protrude a predetermined amount from the seat surface and are slidably inserted into the clamper insertion holes, and the load point is the clamper and the force point is the inner A cutter mounting device comprising a piece and a lever that is assembled into a through hole of the main body by engaging the fulcrum with the main body. (2) The cutter attaching device according to claim 1, which is characterized in that a rotation amount regulating means for the operating shaft is provided between the main body and the operating shaft.