JP2529700Y2 - Indexable tip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a throw-away insert having a curved cutting edge for machining a curved surface.

[Conventional technology]

In a structural material such as a bridge, a fan-shaped notch for avoiding intersection of a joint is provided in a welded joint portion prior to a beveling process in order to eliminate defect welding. It is generally called scalloping, but if a full-form cutter is used for the processing, the economic loss is large, so the applicant has developed an advantageous throw-away insert in this respect and Suggested. In this method, both the upper surface of the square chip and the opposing side surface of one set are formed into a convex circular arc surface, and the intersecting ridge (which curves in a two-dimensional direction) of those surfaces is used as a cutting blade. A plurality of chips are combined to create a fan-shaped blade.

In addition, only the side surface of the triangular or square chip is formed into a convex arc surface, and the chip is used in a state where the side surface is a rake surface and the side surface is inclined in a direction in which the rake angle becomes a negative angle. Things have also been done.

[Problems to be solved by the invention]

The indexable insert disclosed in Japanese Utility Model Application Laid-Open No. 61-120402 requires a long time for processing because both the rake face (side face) and the flank face (top face) are curved, resulting in high cost.

 In addition, since two corners are used as cutting edges, it is uneconomical.

On the other hand, a chip with an arc surface only on the side surface can be used as a cutting edge at all the intersection ridges of the upper and lower surfaces and the side surface. The seat side where the chip fits must be processed into a curved surface that matches the side surface of the chip. However, the processing is difficult, and the adhesiveness of the chip becomes insufficient.

Also, in order to make the side face a rake face and make the blade shape close to the curvature of the machined surface, it is necessary to largely tilt the insert in the direction where the clearance angle becomes large, so the negative rake angle becomes large and the cutting resistance becomes excessive. There are problems such as cutting noise, vibration during cutting, and the like caused by this.

The purpose of the present invention is to provide a throw-away tip that solves the above-mentioned problems.

[Means for solving the problem]

The throw-away tip of the present invention has a quadrangular shape as its original shape, and its upper and lower surfaces are formed into a convex arcuate surface curved in a uniaxial direction. Of the two opposing side surfaces, one of the side surfaces is formed as a V-shaped concave surface having an upper half on the upper surface and the lower half on the lower surface at an acute angle, and the other side surface is formed flat. Further, in the center, a mounting hole passing through the upper and lower surfaces and the upper and lower surfaces are partially flattened in parallel to provide a mounting surface for the convex flat support seat. In this way, the intersection of the V-shaped concave surface and the upper surface is curved downward from the center toward both ends, and the intersection of the V-shaped concave surface and the lower surface is curved in the opposite direction to the former, and a total of four curved ridges are formed. Used as a cutting blade.

Although the above-mentioned chip is a so-called positive type, a negative type, that is, a negative cutting edge (a cutting edge having a 90 ° bevel angle) is formed at the intersection of the side surface of the V-shaped concave surface with the upper and lower surfaces. The purpose of the invention is achieved even if it is replaced with a flat surface.

[Action]

It is easy to manufacture because only the upper and lower surfaces are curved.
Since the corner becomes a cutting edge, it is more economically advantageous than that proposed in Japanese Utility Model Application Laid-Open No. 61-120402.

Further, since the seat has a flat mounting surface, the seat may be processed to be a flat one corresponding to the flat surface, and the contact between the flat surfaces improves the adhesiveness, thereby increasing the stability of fixing.

Furthermore, the flank (upper surface or lower surface) is an arc surface, and if the curvature of the arc surface approaches the curvature of the processing surface, the required cutting edge shape can be obtained without increasing the inclination of the chip in the direction in which the clearance angle changes. Since it can be produced, the rake angle falls within an appropriate range, and an increase in cutting force is avoided. Therefore, cutting noise and vibration are reduced.

〔Example〕

 1 to 3 show an embodiment of the present invention.

As shown in the drawing, the upper surface 2 and the lower surface 3 of the throw-away tip 1 are arcuate surfaces that have the same curvature and are curved uniaxially. One set of opposing side surfaces 4 and 4 is formed in a V-shaped concave shape, and the upper half and the lower half intersect at an acute angle with the upper surface 2 and the lower surface 3 respectively. The other set of opposing side surfaces 5, 5 are vertical flat surfaces. 6 is a ridge formed between the upper surface 2 and the side surface 4, 6 'is a ridge formed between the lower surface 3 and the side surface 4, and the former ridge 6 is curved downward from the center toward both ends. . On the other hand, the latter ridge 6 'is curved symmetrically in the opposite direction to the ridge 6, and the curved ridges 6, 6' are used as cutting edges.

Reference numeral 7 denotes a mounting surface formed by flattening a part of the upper and lower surfaces in parallel, and reference numeral 8 denotes a mounting hole formed in the center of the surface (center of the chip).

As shown in FIG. 4, the tip 1 is fixed to the seat of the tool body 10 with a countersunk screw 11 with the side surface 4 being a rake face and being slightly inclined so that a clearance angle α is formed on the upper surface side. I do. At this time, as shown in FIG. 5, the side surfaces 5 and 5 are brought into close contact with the flat seating surfaces 12 and 12, and the other side surface 4 not involved in cutting is received by the seating surface 13. Also, the mounting surface 8
Is received on a flat support surface 14 that fits into the part. If the support surface 14 is provided on a floor plate 15 that is independent of the main body as shown in the figure, machining of the seat is easy.

In this invention, as shown in FIG. 6, the side surface of the V-shaped concave surface described above is replaced with a flat surface, and the flat side surfaces 4 ', 4' and the upper and lower surfaces 2, 3 perpendicular to the flat side surfaces 4 ', 4' are formed. The present invention is also applicable to a negative type tip using the arcuate ridges 6 and 6 'between them as cutting edges. The rake angle of the negative type insert becomes negative by setting the clearance angle α. However, according to the configuration of the present invention, the negative angle falls within a small range, so that the cutting resistance does not increase extremely.

〔effect〕

As mentioned above, the chip of this invention has a rake face,
It is easier to manufacture than the one that processes two flank surfaces with curved surfaces,
In addition, since four corners serve as cutting edges, it is economically advantageous.

In addition, since it has a flat mounting, support stability is enhanced.
In addition, since the rake angle falls within an appropriate range, cutting resistance is small, and stable machining with little cutting noise and vibration is possible.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of the throw-away insert of the present invention, FIGS. 2 and 3 are side views showing a 90 ° position, and FIG. 4 is a cross-sectional view showing a state of attachment to a tool. , Fifth
The figure is a plan view thereof, and FIG. 6 is a perspective view of another embodiment. 1 ... throw-away tip, 2 ... upper surface, 3 ... lower surface, 4 ... V-shaped concave side surface, 5 ... another set of side surfaces,
6, 6 '... ridge, 7 ... mounting surface, 8 ... mounting hole,
4 '... Flat side.

Claims (2)

(57) [Scope of request for utility model registration] An upper surface and a lower surface are formed in a convex arcuate surface curved in a uniaxial direction, and one of two opposing side surfaces has an upper half in an upper half. On the upper surface, the lower half is formed as a V-shaped concave surface which intersects the lower surface at an acute angle, and the other set of side surfaces is formed flat, and furthermore, a mounting hole and upper and lower surfaces are provided at the center of the chip. A mounting surface is provided on a support seat of a convex flat surface which is partially flattened in parallel. The intersection of the V-shaped concave surface and the upper surface is downward from the center toward both ends, and the intersection of the V-shaped concave surface and the lower surface is provided. A throwaway tip in which the ridges are curved upward from the center toward both ends, and a total of four curved ridges form a cutting edge. 2. The throwaway tip according to claim 1, wherein the side surface of the V-shaped concave surface of the throwaway tip is replaced by a flat surface that generates a negative cutting edge at the intersection with the upper and lower surfaces.