JPH0671682B2 - Throw-away front milling cutter - Google Patents

Description

Description: [Industrial application] The present invention relates to a throwaway type face mill capable of preventing the cutter body from chattering.

[Prior Art] Generally, when a face milling machine is used for cutting, each throwaway tip is an intermittent cut that repeats cutting and non-cutting each time the cutter body makes one revolution. Causes chatter, and the throw-away tip is easily damaged. Therefore, it is desired that chattering is unlikely to occur and that the throw-away tip can be prevented from being damaged.

By the way, as a conventional face milling cutter, for example, a so-called unequal division type face milling cutter is known. In this front milling cutter, a plurality of throwaway tips 1 ... (Only one is shown in the figure) as shown in FIG. 8 are arranged at unequal intervals in the circumferential direction at the tip of a cutter body that is rotated about an axis. The throwaway tip 1 has a main cutting edge 2 and a sub cutting edge 3, and the main cutting edge 2 is provided with a corner angle of θ with respect to the axis, The sub-cutting edge 3 moves the cutter in the feeding direction (8th
It is detachably attached to a cutter body (not shown) so as to be parallel to the arrow A direction in the drawing.

In the face milling machine configured as described above, rough cutting is performed by the main cutting edge 2 of the throw-away tip 1, while finishing is performed by the auxiliary cutting edge 3 positioned so as to be parallel to the feed direction of the cutter. Since the cutting is performed, the surface roughness of the cut surface can be improved. Furthermore, since the plurality of throwaway tips 1 are arranged at unequal intervals in the circumferential direction of the cutter body, the width t of the chips 4 generated by each throwaway tip 1 is different. Therefore, since the cycle and magnitude of the impact force received by the cutter body are irregular, the cutter body does not resonate, and there is an advantage that the chattering can be prevented.

[Problems to be Solved by the Invention] However, in the above face milling machine, there is a problem that it is not possible to sufficiently meet the demand for preventing the cutter body from chattering and preventing the throw-away tip from being damaged. It was That is, in the above face milling machine, since the corner angles θ of the main cutting edges 2 of the throw-away tip 1 are all set to be the same, the thickness of the chips 4 generated during cutting is from the lower edge 4a thereof. It becomes uniform over the upper edge portion 4b. In this case, the magnitude of the impact force received by the main cutting edge 2 of each throwaway tip 1 differs depending on the thickness t of the chips 4, but the thickness of the chips 4 is uniform in the direction in which the impact force acts. To become all the same. Therefore, the main cutting edge 2 of each throwaway tip 1
Is always applied with an impact force in the same direction, and this impact force is transmitted to the cutter body. Since the direction of the impact force transmitted to the cutter body is the same for each throwaway tip 1, the cutter body easily resonates.

[Object of the Invention] The present invention has been made in view of the above circumstances, and the cutter body rarely resonates and chatters. Therefore, it is possible to effectively prevent the throwaway tip from being damaged. Intended to provide milling cutter.

[Means for Solving Problems] The throw-away tip face milling cutter of the present invention has a sub-cutting edge directed toward the tip end of a cutter body that is rotated about an axis, and through this sub-cutting edge. A corner angle is added so that one of the two adjacent main cutting edges faces inward and the other faces outward, and the other main cutting edge gradually separates from the axis as it goes from the front end side to the rear end side. In a throw-away type face milling machine that detachably mounts multiple throw-away inserts of the same shape, the corner angle of the main cutting edge of some throw-away tips is the corner angle of the main cutting edge of other throw-away tips. Unlike, and the auxiliary cutting edge of all throwaway tips,
It is characterized in that they are arranged so as to exist in one plane orthogonal to the axis.

[Operation] With the above configuration, the corner angle of the main cutting edge of some of the throw-away inserts is arranged to be different from the corner angle of the main cutting edge of other throw-away inserts. When cutting a work material with different throw-away tips, the chips with a tapered cross-section whose thickness gradually increases from the lower edge to the upper edge, and from the upper edge to the lower edge. As a result, chips having a tapered cross-section that gradually increase in thickness are generated. Since the direction of the impact force received by the main cutting edge is different between the case of producing the former chips and the case of producing the latter chips, the direction of the impact force transmitted to the cutter body differs depending on each throwaway tip. For this reason,
The cutter body rarely resonates.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

In FIG. 1, reference numeral 5 denotes a cutter body, and six throwaway tips 6 having the same shape and size are detachably attached to the outer periphery of the tip end portion thereof by a wedge member 8 and a clamp screw 9 via a supporter 7, respectively. Is attached to. These throwaway tips 6 ... Are attached with different settings for some throwaway tips and other throwaway tips, as will be described later, so that the angle formed by the main cutting edge 10 and the axis O of the cutter body 5 is made. (Hereinafter referred to as a corner angle) of θ ₁ and θ ₂ (here, θ ₁ <
It is divided into two types, θ ₂ ).

That is, the main cutting edge 10a located on the inner peripheral side of the cutter body 5 of one of the throwaway tips 6a is
Is located on a plane S ₁ parallel to the axis O and separated from one of the center lines L ₁ dividing the outer periphery of the axis L ₁ rearward in the rotational direction by a dimension X. In addition, the main cutting edge 10b of the other throwaway tip 6b located on the inner peripheral side of the cutter body.
Is separated from the center line L ₃ having an angle α with respect to the center line L ₂ that divides the outer circumference of the cutter body 5 into six equal parts rearward in the rotational direction by a dimension Y (where Y <X), and the axis O It is located on a plane S ₂ parallel to it. Where dimension X,
For Y and angle α, each sub cutting edge 11a, 11b ...
It is set so as to be located on a center line that divides the outer circumference of 6 into 6 equal parts.

The main cutting edges 10a, 10b of the respective throwaway tips 6a, 6b located on the outer peripheral side of the cutter body 5 are, as shown in FIGS. 3 and 4, both with respect to the planes S ₁ and S ₂ . has an angle β, and as shown in FIG. 2, the planes S ₁ , S ₂
It is positioned so as to have an angle of γ with respect to a plane S ₃ orthogonal to. As a result, the recesses 5a for attaching the throwaway tips 6a, 6b have the same shape, as shown in FIG. Where the angle β
And γ are set such that the sub cutting edges 11a and 11b are parallel to the feeding direction of the cutter (the direction of arrow A in FIG. 1).

With this arrangement, the corner angle of the main cutting edge 10a is θ ₁ and the corner angle of the main cutting edge 10b is θ ₂ . The two types of throwaway tips 6a and 6b are alternately arranged in the circumferential direction of the cutter body 5.

When cutting is performed using the throwaway type face milling machine configured in this way, the width of the lower edge portion is T and the width of the upper edge portion is T due to the main cutting edge 10a as shown in FIG. 7, respectively. Chips 12 having a size of T ₁ are generated, and chips 13 having a width of the lower edge portion of T and a width of the upper edge portion of T ₂ are generated by the main cutting edge 10b. Here, T is the feed amount per blade of the cutter. Here, since the direction of the impact force received by the main cutting edges 10a and 10b is different between the case where the former chip 12 is generated and the case where the latter chip 13 is generated, the direction of the impact force transmitted to the cutter body 5 is slow. Differs depending on the way tip 6a, 6b. Therefore, the cutter body 5 rarely resonates and chatters, and it is possible to effectively prevent the throwaway tip 6 from being damaged.

Also, in the throwaway type face mill,
Since the auxiliary cutting edge 11 of the same shape and size is positioned so that the auxiliary cutting edge 11 is parallel to the feed direction of the cutter, the corner angle of the main cutting edge 10 can be changed. Can be improved. Further, as is clear from FIGS. 3 and 4, the throwaway tip 6b has a center line L _{3 as} compared with the other throwaway tips 6a.
Since it is located closer to the main cutting edge 10b, the radial rake angle of the main cutting edge 10b is slightly smaller than the radial rake angle of the other main cutting edge 10a, which improves the chip discharge performance. Furthermore, since the throwaway tips 6 ... Have the same relative position with respect to the reference planes S ₁ and S ₂ , the recesses for attaching the throwaway tips are provided.
The processing of 5a can be facilitated.

In the above embodiment, the angle a and β respectively relative to the main cutting edge 10a, a plane S _1, S ₂ of 10b, although the γ respectively an angle with respect to the plane S _3, not limited to such a configuration, the angle The β and the angle γ may be changed by the main cutting edges 10a and 10b. Further, the arrangement may be changed as appropriate, for example, by disposing the two throwaway tips 6b and 6b between the two throwaway tips 6a and 6a that are adjacent to each other in the circumferential direction.

Further, in the above-described embodiment, the dimensions such that the sub cutting edges 11a, 11b ... Are located at equal intervals in the circumferential direction of the cutter body 5.
Although X, Y and the angle α are set, they may be positioned at unequal intervals. Furthermore, in the above-described embodiment, the throwaway tips 6 ... Are divided into two types, the corner angles of which are θ ₁ and θ ₂ , but they may be divided into more types.

[Effects of the Invention] As described above, in the throwaway type front milling cutter according to the present invention, a part of the throwaway tips of the plurality of throwaway tips mounted on the tip portion of the cutter body is used as a main cutting edge. Since the corner angle is arranged so that it is different from the corner angle of the main cutting edge of the remaining throwaway tips, the cutter body rarely resonates and chatters. The effect that it can be prevented is obtained.

[Brief description of drawings]

1 to 7 are views showing an embodiment of the present invention, FIG. 1 is a bottom view showing a front milling cutter, and FIG. 2 is a first view.
II-II line sectional drawing of the figure, FIG. 3 is a III direction arrow view of FIG.
The figure shows the state in which the throwaway tips are arranged with different corner angles, and is a view in the direction of the arrow IV in FIG. 2, and FIG.
6 and FIG. 6, FIG. 6 is a side view showing a throwaway tip, FIG. 7 is a sectional view showing chips produced by each throwaway tip, and FIG. 8 is a conventional face milling machine. It is a side view which shows the throw away tip arrange | positioned at. 1 ... Throw away tip, 2 ... Main cutting edge, 5 ... Cutter body, 6 ... Throw away tip, 10a ... Main cutting edge, 10b ... Main cutting edge, O ... Axis, θ ... Corner Angle, θ ₁ …… Corner angle, θ ₂ …… Corner angle.

Claims (1)

[Claims] 1. A sub-cutting edge is directed toward the tip end of a cutter body that is rotated about an axis, and one of two main cutting edges adjacent to each other via this sub-cutting edge is inward and the other is outside. In addition, a plurality of throwaway inserts of the same shape with corner angles are detachably attached so that the other main cutting edge gradually separates from the axis as the other main cutting edge goes from the front end side to the rear end side. In the throw away type face milling machine, the corner angle of the main cutting edge of some throw away tips is different from the corner angle of the main cutting edge of other throw away tips, and the sub cutting edges of all the throw away tips are A throw-away tip, wherein the throw-away tip is arranged so as to exist in one plane orthogonal to the axis.