JPS5920909Y2 - Combination milling cutter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a combination milling cutter.

Conventionally, when cutting parts with multi-groove shapes, rack shapes, etc., such as steering gear racks for automobiles, racks for machinery, etc., using a milling machine, a total cutter is used that combines multiple cutters into an integrated structure. A milling cutter is used.

Each cutter of this combination milling cutter has the same shape and only 13 keyways are provided for keying to the cutter arbor.

Normally, the position of one keyway provided in each of these cutters is arranged in the same phase with respect to the cutter cutting edge groove, so cutting can be performed by a cutter formed by combining these cutters. When cutting, the cutting blades that are aligned parallel to the cutter rotation axis collide with the workpiece at the same time, resulting in so-called interrupted cutting, which has the disadvantage of causing vibrations, reducing machining accuracy and shortening cutter life. Ta.

To prevent this, some cutters are designed to slightly change the phase of the keyway relative to the position of the cutting edge for each cutter, but in this case, when re-sharpening the cutter cutting groove, the grindstone does not pass in the direction of the cutter axis. Therefore, it is necessary to disassemble the combination milling cutter and re-sharpen the cutters one by one, which has the disadvantage that the number of steps required for re-sharpening increases significantly.

On the other hand, in order to eliminate interrupted cutting, attempts have been made to use an integrated cutter instead of a combination milling cutter and to form the cutting groove in a spiral shape.
In this case, during re-sharpening, the cutter must be rotated appropriately relative to the relative feed between the cutter and the grinding wheel (in the direction of the cutter's axis), and the spiral shape of the cutting grooves also makes the cutting edge more stable. Since the left and right cutting edge angles are different, there are disadvantages in that the cutting performance is poor, resulting in a decrease in the precision of the workpiece and a shortened cutter life.

The present invention has been made to improve the drawbacks of conventional milling cutters that are tilted. The above object is achieved by providing at least one cutter with a keyway having a phase different from the above-mentioned phase.

Embodiments of the present invention shown in FIGS. 1 to 4 will be described below.

In the figure, 1-1, 1-2, . . . are individual cutters constituting the combination cutter 11, 2, 2, . ... is cutter 1-1,
1-2. ... A plurality of cutting blades are formed on the peripheral edge, 3, 3. ... are cutter arbor insertion holes, and 4 and 5 are two keyways provided in each cutter.

The keyway 5 is provided in the same phase with respect to the cutting edge 2 position for each cutter, or the keyway 4 is provided in the first cutter 1-1 and the second cutter 1-2. (In the example shown in Figures 1 and 2, when the keyways are aligned in a line as shown by the dashed line P in Figure 1, the corresponding cutting edges are staggered in the axial direction.) (so that)

6 is a cutter arbor common to each cutter; 7 is a key attached to the cutter arbor 6; 8 is a cutting edge groove which is a part that is re-ground when the cutter wears; 9 is a relatively large diameter bolt insertion hole; 10 is a Tightening pole to be inserted into the hole
-111 is a relatively small diameter bolt insertion hole, and 12 is a tightening bolt to be inserted into the hole.

In the case of Fig. 1, the bolt insertion holes 9 and 11 of the second cutter 1-2 to the ninth cutter 1-9 are circular holes, but the bolt insertion holes 9 and 11 of the first cutter 1-1 are not shown in the figure. Counterbore portions 13 and 14 are provided as shown in FIG.
The 0th cutter 1-16 has a screw hole 15 instead of a circular hole.
and 16 are provided.

Note that the insertion hole 11. is inserted into the relatively small diameter port 1. Spot facing part 14
, the screw holes 16 are provided in the same phase with respect to the position of the cutting blade 2 for each cutter, but the relatively large-diameter Pol I/insertion hole 9, counterbore 13, and screw hole 15 are The first cutter 1-1 and the second cutter 1-2 are in different phases (in this example, as shown in Figures 1 and 2, these holes and counterbores are When you line up,
The corresponding cutting edges are provided alternately (dotted chain line P) in the axial direction.

The procedure for assembling the combination milling cutter having the above configuration will be explained below.

1 and 2 show a state in which the cutters are assembled for cutting, and in this case, each cutter is assembled using the keyway 4 and the bolt insertion hole 9.

In order to facilitate assembly, a shaft is provided with a key having the same shape and size as the cutter arbor 6 and the same shape and size as the key 7, and the cutter 1 is attached to this shaft. ,
1 2. After inserting each keyway 4 in sequence while correctly fitting the key, tightening poles l to 10 are inserted into the poles I and 10.
All the cutters are inserted into the insertion hole 9 and tightened and fixed together, and the cutter thus integrated is removed from the shaft and inserted into the cutter arbor 6, using a well-known method not shown. It is preferable to fix the combination cutter to the cutter arbor 6 with the following steps.

Each cutting edge groove 8 of each cutter combined in this way,
8. ... has a different phase with respect to the position of the key 4 as seen in the figure (in the example in Figure 1, the dashed line P in the figure
(staggered as shown).

Therefore, it is possible to alleviate the permanent interrupted cutting that occurs when cutting using a cutter in which each corresponding cutting edge is aligned parallel to the cutter axis, and it is possible to cut the workpiece smoothly. be.

Next, the blade grooves 8, 8. When re-sharpening the cutters 1-..., each cutter 1-. , 1-2. ... is disassembled, and then assembled using the groove 5 of each cutter key and the relatively small diameter bolt insertion hole 11, as shown in FIGS. 3 and 4.

The procedure is the same as the procedure for assembling for cutting described above, so the explanation thereof will be omitted.

Since the diameter of the tightening bolt 12 used at this time is smaller than the diameter of the previous tightening bolt 10, assembly errors can be prevented.

This effect can also be applied when assembled for cutting as described above.

Each cutting edge groove 8, 8°... of the combined cutter is the third
As seen by the dashed line Q in the figure, it is aligned parallel to the cutter rotation axis.

Therefore, as shown in FIG. 5, the blade groove 8 can be easily polished by the grinding wheel W.

That is, when re-polishing, the cutter 1 is usually supported at both centers installed on the table of the polishing machine, and one center is connected to the cutter 1 via the kerat and also fixed to the index plate. Each time the indexing plate performs indexing, the grinding wheel W is moved relative to the cutter in the cutter rotation axis direction to grind each aligned blade.

In the above embodiment, each cutter is provided with two keyways: a keyway 4 used for cutting and a keyway 5 used for re-polishing. For odd-numbered cutters such as cutters 1-3, keyway 4
Since both the key groove 5 and the key groove 5 are provided in the same phase with respect to the cutting edge, it is also possible to eliminate one side and use only the key groove 4, for example.

Further, in the above embodiment, the second cutter 1-2
, the even-numbered cutters 1-4, etc. are provided with key grooves 4 of different phases, so that the cutting edges of each cutter are arranged alternately in the direction of the cutter rotation axis during cutting. However, if the key grooves are provided with slightly different phases as the process progresses, for example, the second cutter 1-2, the third cutter 1-3, etc.
During cutting, the cutting blade hits the workpiece one after another, making it possible to perform cutting that is almost continuous.

However, if the number of different phases is increased, the number of places where tightening bolts are set will also increase, making it difficult to design and also troublesome to manage, so it is usually preferable to limit the number to about 1 to 4.

Further, in the above embodiment, the first cutter 1-1
and ``The tenth cutter 1-16 was provided with a counterbore and a screw hole, but by attaching an appropriate safety cover etc. to the means (not shown) for fixing this combination cutter to the cutter arbor. It is also possible to eliminate these counterbores and screw holes and tighten them with bolts and nuts.

In this way, it is possible to reduce the number of types of ivy, which is preferable in terms of management.

As explained above, according to the present invention, it is possible to alleviate the need for permanent intermittent cutting when cutting with a combination cutter, it is possible to simplify regrinding and its setup, and the assembly and disassembly procedures are also simple. be.

[Brief explanation of drawings]

Figure 1 is a partial cross-sectional side view showing how the combination milling cutter according to the present invention is assembled during cutting, Figure 2 is an enlarged front view of the cutter shown in Figure 1, and Figure 3 is the assembly when re-grinding. Figure 4 is a front view of the cutter shown in Figure 3, Figure 4 is an enlarged front view of the cutter shown in Figure 3, and Figure 5 is a combination milling cutter. FIG. 3 is a front view showing a state of repolishing. 1... Cutter 2... Cutting blade, 3...
...Cutter arbor search insertion hole, 4,5...
・Keyway, 6...Cutter arbor, 7...
Key, 8... Cutting groove, 9, 11... Bolt insertion hole,
10.12...Tighten with bolts.

Claims (1)

[Scope of utility model registration request] In a combination milling cutter in which a plurality of cutters are combined into an integral structure, a pair of adjacent cutters are provided with key grooves in the same position and phase with respect to the cutting groove, and at least one of the pair of cutters is provided with a key groove in the same position and phase with respect to the cutting groove. A combination milling cutter characterized by having a keyway with a phase different from the phase.