JPH07299638A - Adaptor for internal pin milling machine - Google Patents

Abstract

PURPOSE:To provide a cutter installing adapter by which an internal pin milling cutter can be simply mounted and demounted by accurately centering it without being influence by thermal expansion and positional accuracy of a cutting edge and cutter holding stability are not deteriorated. CONSTITUTION:A taper surface 3 on the side of an adapter 1 to center a cutter by fitting to a taper surface 11 of a cutter 10, is formed on a ring 7 to be connected to an adapter body 9 by a spring leaf 8. Thereby, since axial directional force acting on a taper fitting part or a clearance generated in the fitting part by differential thermal expansion between the cutter 10 and the adapter 1 are absorbed by deformation of the spring leaf 8, displacement of the cutter 10 is not caused.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention improves the attachability / detachability of an internal pin mirror cutter, which mainly carries out rough machining of the outer periphery of the crankshaft pin portion and journal portion with the cutting edge held on the inner peripheral side of the ring-shaped body. The present invention relates to an adapter for mounting a cutter, which is used for the purpose of improving the centering accuracy of the cutter and preventing the cutting edge from being displaced due to thermal deformation.

[0002]

2. Description of the Related Art Generally, in an internal type pin mirror cutter, it is necessary to replace a throw-away tip as a cutting edge at the end of its service life. It is detachably attached and removed from the adapter when the chip is replaced.

When the cutter is attached to the adapter, as shown in FIG. 5, unless the deviation of the axis center in both the X-axis and Y-axis directions falls within a very small range, the cutting edge will be shaken during cutting, resulting in a machining accuracy, Since this causes a decrease in processing stability, a method is used in which the key fitting portion for transmitting torque (driving force) is also used for positioning in the X-axis and Y-axis directions.

That is, three or more constant-pitch (four in 90-degree pitch in the figure) radial key grooves 12 are provided on the outer periphery of the cutter 10, and a key 2 is provided on the adapter 1 in correspondence with the groove.
The width of the key is in the tolerance of the hundredths, and the indexing error of the key groove installation point is 0.02 mm or less, so that the key 2 is precisely fitted to the key groove 12 to center the cutter 10. In this case, the fitting condition of the key fitting part becomes tight due to expansion due to cutting heat, and it takes time to install and remove the cutter immediately after cutting. A technique of providing a tapered fitting portion concentric with the shaft center to exert a centripetal effect on the fitting portion and using the key fitting portion only for torque transmission is disclosed in Japanese Patent Application No. 5-69465.
Proposed in.

[0005]

The temperature rise of the cutter due to cutting heat is generally larger than that of the adapter. for that reason,
The temperature of the cutter and the adapter often differs during use and when the cutter is attached and detached.

In this case, the above-mentioned taper fitting portion has the following problems. FIG. 6 is an explanation thereof, in which 1 is an adapter and 10 is a cutter. The above-mentioned inconvenience means that when the thermal expansion of the cutter 10 is larger than that of the adapter 1, a component force of the radial expansion of the cutter is applied to the fitting portion of the tapered surfaces 3 and 11, and originally, FIG. As shown in FIG. 6B, a gap g1 is formed between the seat surface 4 and the cutter-side mounting surface 12 that should be in close contact with each other, and conversely, the thermal expansion of the adapter 1 is larger than that of the cutter 10. Larger figure 6
As shown in (c), the taper surface 3 is separated from the taper surface 11 to form a gap g2 in the fitting portions on both surfaces, and in any case, the cutting edge is displaced and the machining accuracy is reduced.

Further, in the state of FIG. 6 (c), since the cutter 10 moves easily, the stability of processing also deteriorates.

It is an object of the present invention to eliminate such problems and enable centering of the cutter by taper fitting, which is advantageous in terms of detachability of the cutter, even in applications where machining accuracy is required.

[0009]

In order to solve the above problems, an adapter is improved in the present invention. Specifically, a centering taper surface that is concentric with the shaft center to be fitted into the cutter is provided on a ring that is separate from the adapter body, and the ring is movably inserted into the center hole and inserted through an elastic body. The structure is connected to the body.

[0010]

The gap g1 in FIG. 6 (b) is produced by the axial movement of the cutter acting on the taper fitting portion when the cutter has a large thermal expansion because the taper surface 3a is immovable. On the other hand, when the adapter of the present invention is used, the elastic body is deformed, the ring escapes, and the cutter does not move.

If the thermal expansion of the adapter is larger than that of the cutter, a gap g2 shown in FIG. 6 (c) is produced, but when there is no difference in thermal expansion (that is, when the cutter and the adapter are at the same temperature), they are elastic. If the body is deformed, the ring is displaced by the restoring force of the elastic body and absorbs the gap g2 when a difference in thermal expansion occurs, so that the movement of the cutter in the radial direction can be prevented, and therefore the cutting blade can be prevented from moving due to displacement of the cutter. Positional displacement does not occur and cutting stability does not deteriorate.

[0012]

FIG. 1 shows an example of the adapter of the present invention. The ring-shaped adapter 1 includes a recessed seat surface 4 for closely attaching the mounting surface 12 of the cutter 10, a rotary engagement type clamp 5, and a bolt 6 for tightening the clamp.
A torque transmitting key 2 to be fitted in a key groove 13 on the outer periphery of the cutter and an annular tapered surface 3 for centering the cutter are provided.

The tapered surface 3 is processed into a ring 7,
Is connected to the body 9 of the adapter via a spring plate 8.
The ring 7 is loosely inserted into the central hole of the body 9, while
The connection by the spring plate 8 is performed so that the tapered surface 3 is kept concentric with the main body 9.

The cutter 1 is attached to the adapter 1 thus constructed.
When 0 is attached, the taper surface 11 on the cutter side contacts the taper surface 3 provided on the ring 7, and the centering action of this portion causes the cutter 10 to be accurately centered. At this time, the sizes of the ring 7 and the cutter 10 are adjusted so that the ring 7 is pushed by the taper portion of the cutter 10 and slightly retracts in the axial direction so that the spring plate 8 is slightly elastically deformed.

The cutter 10 thus centered is
The clamp 5 presses against the seat surface 4 to fix it. Clamp 5
Allows the rotation from the illustrated clamping point to the unclamping point where the engagement with the cutter 10 is released when the bolt 6 passed through the center is loosened, or vice versa. It is a clamp that is already heavily used for.

The operation of the illustrated adapter will be described below with reference to FIG.

FIG. 2A shows an adapter 1 and a cutter 10.
Is the state when there is no difference in thermal expansion between the two at the same temperature. At this time, since the spring plate 8 is elastically deformed to some extent as shown in the drawing, if the thermal expansion of the adapter 1 is larger than that of the cutter 10, the deformation of the spring plate 8 becomes small as shown in FIG. The expansion difference is absorbed. Also, cutter 1
In the case where the thermal expansion of 0 is larger than that of the adapter 1, the thermal expansion difference is absorbed by the larger deformation of the spring plate 8 as shown in FIG. Instead, it is held stable.

The spring plate 8 may be formed integrally with the main body of the adapter 1 or the ring 7. Also,
The tapered surface 3 may be a convex curved surface as shown in FIG. This convex curved surface is a tapered surface 11 due to the movement of the ring.
It is preferable to a flat taper surface because it reduces the fluctuation of the contact point with.

Further, as shown in FIG.
The same purpose can be achieved by a structure provided on the outer peripheral side edge portion of the ring 7.

[0020]

As described above, according to the present invention, it is possible to eliminate the problems found in the taper fitting centering type adapter which is advantageous in terms of attaching and detaching the cutter. That is, the difference in thermal expansion between the cutter and the adapter absorbs the axial component force acting on the taper fitting portion between them and the gap generated in the taper fitting portion, so that the taper surface is kept in close contact with the cutter centering effect. Can't be lost.

Further, the cutter does not move in the axial direction and does not move in the radial direction, the position of the cutting edge and the holding of the cutter are stable, and the processing accuracy and the processing stability are improved.

[Brief description of drawings]

FIG. 1A is a plan view showing an example of an adapter of the present invention with a cutter attached. FIG. 1B is an enlarged cross-sectional view taken along line AA of the same.

FIG. 2A is a diagram showing a state of a tapered fitting portion when the cutter and the adapter have the same temperature. FIG. 2B is a diagram of a tapered fitting portion when thermal expansion of the adapter is larger than that of the cutter. : Diagram of taper mating part when the thermal expansion of the cutter is larger than that of the adapter

FIG. 3 is a view showing a modified example of a tapered surface provided on a ring.

FIG. 4 is a diagram showing an example in which a tapered surface provided on the ring is provided on the outer peripheral side of the ring.

FIG. 5 is a front view of a conventional adapter.

FIG. 6 shows the operation of a conventional adapter as shown in FIGS.
(C) Diagram shown in correspondence with diagram

[Explanation of symbols]

 1 Adapter 2 Key 3 Tapered surface 4 Seat surface 5 Clamp 6 Bolt 7 Ring 8 Spring plate 9 Main body 10 Cutter 11 Tapered surface 12 Mounting surface

Claims (1)

[Claims] 1. An adapter for attaching a cutter interposed between an internal pin mirror cutter and a processing machine,
An adapter having a tapered surface concentric with the shaft center on the inner diameter side, and fitting a tapered portion provided corresponding to the cutter body to the tapered surface to center the cutter, the tapered surface is separated from the main body. An internal pin mirror adapter, which is provided on a ring, is movably inserted into a center hole, and is connected to a main body via an elastic body.