JP3805060B2 - Diamond sintered body chip - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a diamond sintered body chip, and in particular, to a technique for making a processed surface of brass, aluminum alloy or the like a matte surface in the optical equipment industry.
[0002]
[Prior art]
Conventionally, in processing using a diamond sintered body chip in the technical field, processing using a sharp edge that is not subjected to cutting edge processing has been common. Since the processed surface was formed with a sharp cutting edge, the processed surface was a glossy surface in which feed marks appeared remarkably. In order to obtain the matte surface which is the object of the present invention, surface treatment such as sandblasting or shot peening has been performed as a post-process. That is, in order to obtain a matte surface, two steps of cutting and surface treatment were required, so that the processing efficiency was poor and the processing cost was disadvantageous. Therefore, the present invention is designed to obtain a matte surface by studying the honing shape applied to the diamond sintered body chip. However, the conventional technology related to this type of honing shape has a cutting edge. The purpose was to strengthen and extend the tool life.
[0003]
For example, as a first conventional technique in which cutting edge processing is performed, for example, one disclosed in Japanese Patent Laid-Open No. 2-30407 is known. In the technique, as shown in FIG. 3, the cutting edge is formed in a chamfered shape where the honing width a on the rake face 2 side is larger than the honing width b on the flank face 3 side at the intersection of the rake face 2 and the flank face 3. It is a thing. When the radius of curvature continuously connected to the rake face 2 is R1, the radius of curvature continuously connected to the flank 3 is R2, and the radius of curvature of the portion connecting the curved surfaces of R1 and R2 is R0. , R1 <R2 <R0.
[0004]
FIG. 4 shows the second prior art disclosed in Japanese Patent Publication No. 1-386601. Also in this honing shape, the cutting edge is a composite honing composed of a curved surface protruding outward. When the honing width in the direction of the rake face 2 is a and the honing width in the direction of the flank 3 is b, the relationship is formed as b> a. With such a configuration, a reduction in wear resistance in high-speed, high-feed cutting is prevented.
[0005]
Furthermore, since the contact area between the honing surface 4 and the work material is wide, the cutting edge retraction phenomenon due to plastic deformation hardly occurs, and the machining accuracy can be maintained high. In addition, the large negative angle honing shape can maintain toughness and also has an effect of preventing defects.
[0006]
[Problems to be solved by the invention]
The one with arc honing on the cutting edge can give a burnishing action between the work flank and the chip flank facing the work material. The processed surface may be damaged by chip biting or welding.
[0007]
In the first conventional technique, a sharp cutting edge is chamfered at a predetermined chamfering angle. As the chamfering angle increases, the sharpness becomes worse. Therefore, this technique suppresses the increase in cutting resistance and reduces the chamfering angle so as not to impair the sharpness. This technique is intended to strengthen cutting edges formed of high hardness materials such as cemented carbide, cermet and ceramics, and is suitable for cutting steel materials. Not suitable for matte cutting of certain light alloys.
[0008]
Furthermore, the second prior art also relates to a cutting tool made of a hard material such as cemented carbide, cermet, ceramics, etc., and is generated at the time of cutting because the honing surface is arranged to face the work material. A large amount of heat can be released to the work material side, and a local temperature rise of the cutting edge can be suppressed. In particular, it is advantageous in high-speed and high-feed cutting such as steel and cast iron. However, in matte cutting of light alloys, it is the geometric curved surface shape on the flank side that determines the quality of the machined surface by the burnishing action. Therefore, simply specifying the chamfer angle and honing width is not an essential solution for obtaining the matte surface that is the object of the present invention. In addition, if the chamfering angle is large, chips may be bitten or welded material may be generated on the cutting edge, which may damage the processed surface.
[0009]
[Means for Solving the Problems]
The present invention has been made in view of the problems as described above, and in the diamond sintered body chip used for cutting nonferrous metal , arc honing is provided to a cutting edge formed by intersecting a rake face and a flank face. The honing is formed by a curved surface having a radius of curvature R1 continuously connected to the rake face, a curved surface having a radius of curvature R2 continuously connected to the flank, and a curved surface having a radius of curvature R0 between the curved surfaces . Each of the curvature radii R1, R2, and R0 has a relationship of R1 <R0 <R2 .
[0010]
The radius of curvature R1 is R1 = 0.01 mm to 0.03 mm, the radius of curvature R2 is R2 = 0.05 mm to 0.1 mm, and the radius of curvature R0 is R0> 0.03 mm. It is characterized by that.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0012]
Since the diamond sintered body easily reacts with an iron group metal, it is used for processing non-ferrous metals. In addition, it has excellent wear resistance and welding resistance, and in addition, it can maintain stable surface roughness without forming a deteriorated layer on the processed surface, so that brass, aluminum alloy, etc., which are the technical field of the present invention, can be used. Suitable for processing optical equipment parts used as materials. In addition, high-efficiency machining with high rotation is possible and the tool life is long.
[0013]
FIG. 1 is a cross-sectional view of a cutting edge portion of a sintered diamond chip (hereinafter referred to as “chip”) 1 according to the present invention. This chip 1 has a polygonal flat plate shape, and is roughly configured by joining a diamond sintered body in a notch step portion at the upper corner of a base made of cemented carbide. The upper surface of the chip 1 constitutes a rake face 2, and a flank 3 is formed at a predetermined angle with the rake face 2. A cutting edge is provided at a portion along the line of intersection between the rake face 2 and the flank face 3. When the cutting edge is enlarged, it has a honing shape formed by a plurality of curved surfaces. Since the honing shape greatly affects the quality of the machined surface and the tool life, it is one of the most important factors in designing the shape of the chip 1. This is particularly important in a diamond sintered body that is inferior in toughness compared to a cemented carbide because it tends to cause chipping and the like.
[0014]
The sectional view and the honing shape are composite arc honing formed from a curved surface convex outward, and the shape is composed of three curved surfaces. A curved surface having a radius of curvature R1 continuously connected to the rake face 2, a curved surface having a radius of curvature R2 continuously connected to the flank 3, and a curved surface having a radius of curvature R0 of an intermediate portion connecting the two curved surfaces. The curvature radius has a relationship of R1 <R0 <R2, and the curvature radius gradually decreases from the flank 3 side toward the rake face 2 side. The radii of curvature R1, R2, and R0 are formed such that R1 = 0.01 mm to 0.03 mm, R2 = 0.05 mm to 0.1 mm, and R0> 0.03 mm.
[0015]
In the conventional arc honing 7, in order to provide the burnishing action, the honing shape has to be increased, and the chip dischargeability and sharpness are unavoidable. On the other hand, there is also a risk of chipping or chipping due to an increase in the back component of the cutting force. The composite arc honing according to the present invention is such that the radius of curvature is gradually reduced from the flank 3 side to the rake face 2 side, and as shown in the figure, the honing shape can be made small, chip dischargeability, sharpness. The effect equivalent to the burnishing action mentioned above can be given, without reducing.
[0016]
Further, in the conventional chamfering honing, as shown in FIGS. 3 and 4, the chamfering angle θ is reduced to improve the sharpness, or the chamfering angle θ is increased to improve the fracture resistance. The shape was specified. However, the former is not suitable for matte cutting of light alloys, which is an object of the present invention, because of its good sharpness. In the latter case, the machined surface may be scratched by biting chips or generating welds on the cutting edge.
[0017]
FIG. 2 is an enlarged view of the contact state between the tip 1 and the work material 6 and shows a conceptual diagram regarding the burnishing action and chip discharge. By forming the radius of curvature R2 of the arc on the side of the flank 3 large, a burnishing action is imparted, and by forming the curvature radii R1 and R0 smaller than the curvature radius R2, a reduction in chip discharge is prevented, Maintains sharpness. Sharpness is important to avoid soft metal flaking or digging.
[0018]
In the tip 1 of the present invention having such a configuration, the tip comes into contact with the work material over a wide area, which is advantageous in producing a burnishing action due to friction with the work material. Further, it is possible to stably generate a matte surface without scratching the processed surface due to chip biting or welding.
[0019]
An outline of an example in which matting processing is performed using the chip 1 according to the present invention will be described. When the outer periphery of a brass ring having an outer diameter of 60 mm and a width of 20 mm was processed while changing the honing shape, the matte degree of the finished surface increased as the arc radius of curvature R2 increased. However, when the curvature radius R2 exceeded 0.1 mm, scratches were generated on the processed surface. That is, the said Example has shown that the upper limit curvature radius with which a matt surface is obtained exists without a crack. The curvature radii R1 and R0 are determined from the viewpoint of the balance between the cutting edge strength and the chip disposal when the curvature radius R2 is used as a reference. The matte surface was hardly changed with an increase in the number of processing, and 10,000 or more could be processed stably.
[0020]
【The invention's effect】
When brass is processed using a conventional diamond sintered body chip, a remarkable glossy surface of the feed mark is obtained. For this reason, color unevenness due to adhesion of fingerprints and dirt is generated, which is not preferable in appearance. In order to obtain a matte surface with moderately deteriorated surface roughness, post-processes such as sandblasting and shot peening have been performed as post-processes for cutting. According to the chip of the present invention, the two steps of the cutting step and the surface treatment step can be performed at one time, and the processing time can be shortened and the processing cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a tip of a sintered diamond tool showing an embodiment of the present invention.
FIG. 2 is a conceptual diagram illustrating a state of matting cutting.
FIG. 3 is a sectional view of a tool tip showing a first conventional example.
FIG. 4 is a sectional view of a tool tip showing a second conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Diamond sintered compact chip | tip 2 Rake face 3 Relief face 4 Honing face 6 Work material R1 Radius of curvature R2 which continues with a rake face R2 Curvature radius R0 which continues to a flank curvature radius of curvature arc which connects R1 and R2 Chamfer angle

Claims (2)

Arc honing is applied to the cutting edge formed by intersecting the rake face 2 and the flank face 3, and in the sintered diamond chip 1 used for cutting non-ferrous metal , the honing is continuously connected to the rake face 2. Formed by a curved surface having a radius of curvature R1, a curved surface having a radius of curvature R2 continuously connected to the flank 3, and a curved surface having a radius of curvature R0 between the curved surfaces, and the respective curvature radii R1, R2, and R0 are A diamond sintered body chip characterized by R1 <R0 <R2 . The radius of curvature R1 is R1 = 0.01 mm to 0.03 mm, the radius of curvature R2 is R2 = 0.05 mm to 0.1 mm, and the radius of curvature R0 is R0> 0.03 mm. The diamond sintered body chip according to claim 1 , wherein the chip is a sintered diamond chip.

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