JPS5821609Y2 - milling tool - Google Patents

Description

[Detailed description of the invention] This invention relates to a milling tool such as a side cutter.

Conventionally, for example, a side cutter has a plurality of chip mounting seats 2 on the periphery of a cutter body 1, as shown in FIG.
is formed into a saw blade shape, and a cutting edge 3 is provided at the tip of this chip mounting seat 2.
It is constructed by attaching a tip 4 made of cemented carbide having a shape, and is configured to perform cutting by rotationally driving the tip 4.

However, in this type of side cutter, the rake surface of the chip 4 is a flat surface, and the chip pocket 5 is formed as a relatively sharply curved recess, and furthermore, the rake surface and the chip pocket 5 are smooth. Since the chips are not continuous, the cutting waste cannot be discharged smoothly, and the cutting waste may clog or adhere to the chip pocket 5, resulting in a problem that the machinability is significantly reduced.

This invention was made in view of the above circumstances, and its purpose is to smoothly discharge cutting waste, and to
It is an object of the present invention to provide a milling tool that can be cut in good condition.

Hereinafter, a first embodiment of this invention will be described in detail based on FIGS. 2 and 3.

Components in the figure that are the same as those shown in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted.

In the milling tool of this invention, the rake surface 7 of the tip 4' having the cutting edge 8 and the pocket bottom surface 5'a defining the pocket 5' are formed by one circular arc surface.

Moreover, this arcuate surface is set so that the rake angle (radial rake angle) at the cutting edge 3 of the rake face 7 is a positive rake angle.

Further, a back metal portion 11 is formed at the back of the tip mounting seat 2 at the periphery of the cutter body 1 to support the tip 4' against cutting loads.

A chamfer 12 is formed between the back metal portion 11 and the pocket bottom surface 5'a.

This chamfer 12 is intended to increase the volume of the pocket 5' and reduce the contact area between the chips and the pocket bottom surface 5/a, and is designed to connect the straight line l passing through the center O of the cutter body 1 to the pocket bottom surface 5/a. It extends toward the outer periphery of the back metal portion 11 from the contact point P with the end portion of the back metal portion 11 side of a or the vicinity thereof.

When cutting is performed using a milling tool configured in this way, since the rake face 7 and the pocket bottom face 5/a are formed by one circular arc surface, chips are transferred from the rake face 7 to the pocket 5'. smoothly transitions to.

By the way, the chips that have migrated to pocket 5' are removed from pocket 5'.
'In order to discharge to the outside, it is advantageous to make the chamfer 12 larger.

However, when the chamfer 12 is made larger, the width of the back metal portion 11 (width from the chip mounting seat 2 in the direction opposite to the cutter rotation direction) becomes smaller.
There is a risk that the rigidity of the cutting edge 1 will decrease, resulting in chatter vibration, breakage of the cutting edge 8, etc.

Conversely, if the size of the chamfer 12 is made smaller, that is, if the chamfer 12 is formed on the outer circumferential side of the contact point P, the rigidity of the back metal portion 11 is improved, but the pocket 5'
Not only does the volume of the chip become smaller and the length of contact between the chips and the pocket bottom surface 5/a becomes longer, but also the end of the pocket bottom surface 5'a on the chip mounting seat 2 side faces toward the center of the cutter body 1. This results in poor chip evacuation.

In this regard, in the milling tool of this invention, the chamfer 12 is not simply formed between the pocket bottom surface 5/a and the back metal portion 11, but is chamfered from the contact point P between the straight line l and the pocket bottom surface 5'a. 12 is formed.

Therefore, it is possible to further improve the chip evacuation performance without substantially reducing the rigidity of the back metal portion 11.

Next, a second embodiment of this invention will be described in detail with reference to FIGS. 4 and 5.

In the figure, the same components as those shown in FIGS. 1 to 3 are denoted by the same reference numerals, and the explanation thereof will be omitted.

Also in the side cutter of this second embodiment, the tip 4"
The rake surface 7 of the pocket 5" and the pocket bottom surface 5"a of the pocket 5" are formed by one circular arc surface, and the space between the pocket bottom surface 5"a and the back metal part 11 is the same as in the first embodiment. A chamfer 12 is formed.

Further, in this second embodiment, the chips 4''... are arranged as follows.

That is, any one of the chips 4"a among the chips 4"... has two cutting edges 9, 9 located on the same straight line with a predetermined distance a+a as shown in FIG. The cutting edges 9, 9 are set at a predetermined axial rake angle θ (approximately 5°), and the negative side, that is, the cutting edges 9, 9 No cutting edge is formed on one side where the angle formed by the straight line and the periphery of the tip 4''a is an obtuse angle.

Further, the next chip 4'b adjacent to the chip 4"a is provided with cutting edges 10, 10 corresponding to the spacing a s a between the cutting blades 9, 9 of the chip 4"a, and , the cutting edge 10.10 is formed slightly wider than the interval ata between the cutting edges 9, 9, and the cutting edge 10.10 is opposite to the axial rake angle θ (approximately 5°) of the cutting edges 9, 9. The cutting edge 10.10 of this tip 4"b cuts the portion not cut by the cutting edges 9, 9.

In this way, the chip 4"a and the chip 4"b
A side cutter is constructed by sequentially and alternately attaching the chips to the chip mounting seat 2.

Next, a case will be described in which cutting is performed using the side cutter configured as described above.

In this side cutter, chips are smoothly discharged from the pocket 5'' as in the first embodiment, but this side cutter also has the effect of being able to carry out heavy cutting. It will be done.

That is, when cutting is performed by the tip 4"a, since the cutting edges 9, 9 of the tip 4"a have an appropriate interval aja, cutting is not performed in the part of this interval a. , the cutting resistance at the tip 4''a is reduced by an amount corresponding to the distance a.

When the cutting edges 10.10 of the tip 4"b of this extraction method come into contact with the workpiece, the cutting edges io, io slightly overlap the parts of the workpiece that are not cut by the cutting blades 9, 9. Since cutting is performed in a lapped state, cutting resistance is reduced and the processed portion of the workpiece can be completely cut.

As a result, the side cutter allows heavy cutting with a wide cutting width.

In addition, in the above embodiment, the cutting edge s of the tip 4"ay4"b
, s, io, and io are configured to be inclined in opposite directions by an axial rake angle θ, but the present invention is not limited to this. Of course, it may be formed to be a straight line parallel to the central axis.

As explained in detail above, according to the milling tool of this invention, the rake face of the cutting edge and the bottom of the pocket are formed by one circular arc surface, and the pocket is formed between the bottom of the pocket and the outer periphery of the back metal part. Since a chamfer is formed that extends toward the outer periphery of the back metal part from the point of contact between the bottom surface and the straight line passing through the center of the cutter body or its vicinity, chip evacuation can be improved without reducing the rigidity of the back metal part. Effects such as being able to achieve the desired results can be obtained.

[Brief explanation of drawings]

Fig. 1 is a front view showing a conventional side cutter, Fig. 2 is a front view showing a first embodiment of this invention, Fig. 3 is a partially cutaway side view thereof, and Fig. 4 is a second embodiment of this invention. FIG. 5 is a front view showing an example, and FIG. 5 is a partially cutaway side view thereof. 1:...Cutter body, 3, 8, 9, 10...
...Cutting blade, 5', 5"...Pocket, 5'a
, 5"a... bottom of pocket, 7...
・Rake face, 11...Back metal part, 12・
... Chamfer, L ... Straight line, 0 ...
・Center, P...Contact point.

Claims (1)

[Scope of utility model registration request] a plurality of cutting blades that are spaced apart from each other in the circumferential direction on the periphery of the cutter body; a pocket adjacent to the rake face of the cutting blade;
In the milling tool, the rake face of the cutting edge and the bottom surface of the pocket defining the pocket are connected to each other so that the rake angle of the cutting edge is positive. A straight line passing through the end of the pocket bottom on the back metal part side and the center of the cutter body is formed between the pocket bottom surface and the outer periphery of the back metal part, and is formed by one circular arc surface so as to form a corner. A milling tool characterized in that a chamfer is formed extending toward the outer periphery of the back metal portion from the junction with or in the vicinity thereof.