JP3124503U - Circular saw with chip guide surface - Google Patents

Abstract

A circular saw having a chip guide surface with significantly improved product life is provided.
A chip seat is cut out in a plurality of tooth bodies provided on an outer periphery of a base metal, and a hard chip mainly made of a cemented carbide is joined to the chip seat. On the front surface 48a in the rotational direction of the hard tip 48, a chip guide surface 56 is formed for guiding the chip of the workpiece to be wound. Further, a concave portion 54 is formed on the upper portion of the cemented carbide substrate 50, and a cutting edge portion 52 including the polycrystalline diamond sintered body 60 is joined to the concave portion 54. In other words, this polycrystalline diamond sintered body 60 is located on the rake face 60 b where the hard tip 48 is most worn, and is provided so as to continue to the chip guiding face 56.
[Selection] Figure 2

Description

  The present invention relates to a circular saw having a chip guide surface used when cutting ferrous or non-ferrous metallic materials.

  A tip saw in which hard tips made of cemented carbide are joined to a plurality of tooth bodies, respectively, is widely known as a circular saw used when cutting a workpiece. In some circular saws having such a hard tip, in order to facilitate the discharge of chips generated at the time of cutting, a rake face and a chip guide surface following the rake face are formed on the rotating front surface of the hard tip. FIG. 8 is an enlarged view of the circular saw 10 having such a chip guide surface 14, and a plurality (only one is shown in FIG. 8) is provided on the outer periphery of a base metal 16 constituting the circular saw body. The hard tip 12 is joined to the tooth body 18. The rake face 20 of the hard tip 12 is formed from a first rake face 22 located at the tip of the tip 12 and a second rake face 32 extending to the saw center side following the first rake face 22. At the same time, a chip guide surface 14 following the lower edge of the second rake face 32 is provided so as to extend toward the center of the saw and forward of rotation.

That is, when cutting the workpiece (not shown) using the circular saw 10, chips of the workpiece cut by the first rake face 22 slide on the surface of the second rake face 32. The chip guide surface 14 is pushed forward and curved. The curved chips are spirally wound and discharged smoothly to the outside. This makes it possible to avoid problems such as chip biting by the hard tip 12 and adhesion peeling of the rake face 20, which have occurred due to the delay in chip discharge, and particularly iron-based and non-ferrous-based. This is effective for cutting materials (for example, see Patent Document 1).
Japanese Examined Patent Publication No. 7-49168

  By the way, it is desirable from the viewpoint of energy saving and cost that the cutting ability can be recovered by re-polishing the cutting edge of the worn hard tip 12 when the circular saw 10 is worn and deteriorated by use and the cutting ability is lowered. However, since the circular saw 10 has the chip guide surface 14 following the rake face 20 of the hard tip 12 as described above, when the tip 12 is polished, the cutting edge (rake face 20), the chip guide surface 14 and There is a problem in that the proper positional relationship is broken and the smooth discharge of chips is impaired. Accordingly, the circular saw 10 having such a chip guide surface 14 is used as a so-called single-use type (slow-away type) in which when a cutting ability is reduced due to use, a new circular saw is replaced without considering reuse. The fact is that we have to do it. For these reasons, the greatest problem for the circular saw 10 having the chip guide surface 14 is to improve the product life.

  In view of the above-described problems inherent in the prior art, the present invention has been proposed to suitably solve this problem, and a circular saw having a chip guide surface that greatly improves the product life. The purpose is to provide.

In order to overcome the above problems and achieve the intended purpose, a circular saw having a chip guide surface according to the present invention,
A chip guide surface that is provided with a hard tip on each of the tooth bodies provided on the outer periphery of the base metal, forms a rake face on the outer peripheral side of the front surface in the rotation direction of the hard tip, and guides the chips of the workpiece to be wound. Is a circular saw formed continuously on the saw center side of the rake face in the hard tip,
The outermost peripheral portion of the hard tip made of cemented carbide is formed of a super-hard sintered body made of a polycrystalline diamond (PCD) sintered body or a boron nitride (CBN) sintered body, and the rake face is made of the ultra-hard sintered body. It is characterized by comprising a ligation.
According to the first aspect of the present invention, the outermost peripheral portion of the hard tip is formed of an ultra-hard sintered body, and the rake face is formed of the ultra-hard sintered body. Product life can be greatly improved. In addition, since the ultra-hard sintered body is used only in the hardest part of the hard tip, the required amount of the ultra-hard sintered body can be minimized and the increase in cost can be suppressed as much as possible.

In order to overcome the above-mentioned problems and achieve the intended purpose, a circular saw having a chip guide surface according to another device of the present application,
A hard tip is provided on each of the plurality of tooth bodies provided on the outer periphery of the base metal, and a second rake face located on the outer peripheral side of the front surface in the rotational direction of the hard tip and a second rake surface following the first rake face side of the first rake face. A circular saw in which a rake face composed of a rake face is formed on a hard tip, and a chip guide surface for guiding the chip of the workpiece to be wound is continuously formed on the side of the saw of the second rake face in the hard tip. Because
The outermost peripheral portion of the hard tip made of cemented carbide is formed of a super-hard sintered body made of a polycrystalline diamond (PCD) sintered body or a boron nitride (CBN) sintered body, and at least the first rake face is super It is characterized by comprising a hard sintered body.
According to the second aspect of the invention, in addition to the same effect as the first aspect of the invention, the rake face is formed of the first rake face and the second rake face, so that the cutting of the iron-based work material is performed. Particularly preferred.

  According to the circular saw having the chip guide surface according to the present invention, wear deterioration due to use can be suppressed and the product life can be greatly improved.

  Next, a circular saw having a chip guide surface according to the present invention will be described below with reference to the accompanying drawings with a preferred embodiment.

  In Example 1 corresponding to the invention according to claim 1, a case will be described in which polycrystalline diamond suitable for cutting a non-ferrous metal is adopted as the ultra-hard sintered body. FIG. 1 is an overall view of a circular saw 40 having a chip guide surface according to the first embodiment, and a plurality of tooth bodies 44 are formed at predetermined intervals on the outer periphery of a base metal 42 which is the main body of the circular saw 40. Has been. As shown in FIG. 2, each tooth body 44 has a notch formed on a chip seat 46 that opens in the radial direction and the rotational direction side of the circular saw 40, and the chip seat 46 is mainly made of a cemented carbide. 48 is joined by joining means such as brazing. In the description of the hard tip 48, “upper and lower” are designated in the state shown in FIG. 2, and “front and rear” are designated with respect to the rotation direction of the circular saw 40.

  The hard tip 48 according to the first embodiment includes a substantially rectangular carbide substrate 50 and a blade edge portion 52. As shown in FIG. 5, the cemented carbide substrate 50 is formed with a concave portion 54 capable of accommodating and fixing the cutting edge portion 52 at an upper portion thereof, and the cemented carbide substrate 50 is formed from a front edge 54 a of the concave portion 54. A curved chip guiding surface 56 is formed on the front surface portion 50a. Further, the cutting edge portion 52 brazed to the cemented carbide substrate 50 in the state of being accommodated in the recess 54 includes a substrate 58 made of cemented carbide formed in a parallelepiped shape, and the substrate, as shown in FIG. A polycrystalline diamond (PCD) sintered body (ultra-hard sintered body) 60 provided on the front side of 58 is integrally formed. That is, as shown in FIG. 2, the hard tip 48 is harder than the cemented carbide at the tip end portion (outermost peripheral portion) on the front side 48a in the rotational direction, which is the portion where the wear is most severe when cutting. A PCD sintered body 60 that is a very high-pressure sintered body is provided, and the wear resistance of the hard chip 48 is greatly improved. Furthermore, as shown in FIG. 2, the lower edge 60a of the front rake face 60b of the PCD sintered body 60 and the upper edge of the chip guiding surface 56 (the edge part 54a of the concave part 54) substantially coincide with each other. A continuous surface is formed, and smooth discharge of the chips 64 generated from the workpiece 62 during cutting is realized (see FIG. 6).

  Here, a specific manufacturing process of the cutting edge portion 52 will be described. As shown in FIG. 4, polycrystalline diamond obtained by sintering synthetic diamond microcrystals simultaneously with various binders at high temperature and high pressure. (PCD) A sintered body blank 66 is prepared. The PCD blank 66 is, for example, a disk shape having a diameter of about 70 mm and a thickness of about 3 mm, and has a two-layer structure of a cemented carbide layer base member 59 and a PCD layer 61. Furthermore, if necessary, it is possible to suppress the chips 64 of the workpiece 62 from being welded to the cutting edge portion 52 by performing mirror polishing on the ultra-high pressure sintered body blank 66.

  Next, the ultra-high pressure sintered body blank 66 is cut at regular intervals by, for example, a discharge wire cutting method. Then, as shown in FIG. 4B, the divided body 67 cut out at equal intervals is cut at equal intervals at the required inclination angle θ by the same discharge wire cutting method, so that the PCD is formed at the tip portion. A plurality of parallelepiped cutting edge portions 52 having a sintered body 60 are created (see FIG. 4C). Here, since the PCD sintered body 60 is particularly preferably used for cutting a non-ferrous metal material having a hardness lower than that of a ferrous metal, for example, an aluminum alloy, as shown in FIG. The rake angle α of the body 60 is set to the plus side (positive). That is, the rake angle α of the hard tip 48 is defined by the cutting incident angle θ of the wire with respect to the divided body 67 shown in FIG.

  The cutting edge portion 52 formed by the above process is seated and fixed in the concave portion 54 of the cemented carbide substrate 50. Here, when joining the blade edge portion 52, the high frequency silver brazing used for joining general tip saws is insufficient in strength. For example, the blade edge portion 52 is formed using an insert metal material having a high melting point. It is joined. That is, when the cutting edge portion 52 and the cemented carbide substrate 50 are joined, an insert metal having a higher melting point than silver brazing is used, and welding is performed by a method such as brazing, laser welding, or resistance welding. As described above, the rake face 60b of the PCD sintered body 60 and the chip guiding surface 56 are configured to form a substantially continuous surface, so that the chips 64 at the time of cutting are efficiently passed through the chip guiding surface 56. Are being discharged.

  In addition, when forming the chip | tip guidance surface 56 and the recessed part 54 in the cemented carbide base material 50, the shaping | molding process by the above-mentioned electric discharge type wire cut method is especially suitable. In addition, when cutting a soft metal such as an aluminum alloy, it is not necessary to provide the first rake face 22 having the negative rake angle described in the description of the prior art, but a single rake face corresponding to the second rake face 32 having a positive rake angle. Only one rake face 60b may be provided on the hard chip 48. However, in the case of hard metal cutting, it is desirable to polish the upper part of the rake face 60b to form a second rake face having a negative rake angle from the viewpoint of improving the chip resistance. Further, if necessary, the upper portion of the blade edge portion 52 may be polished so that the tip clearance angle β of the blade edge portion 52 is slightly smaller than the tip clearance angle β ′ before polishing (see FIG. 3). ). Thereby, the chipping resistance of the tip of the blade edge portion 52 generated during cutting can be further improved. Furthermore, the same WC sintered body as that of the substrate 58 is adopted as the material of the cemented carbide substrate 50.

(Operation of Example 1)
Next, the operation of the circular saw having the chip guide surface according to the first embodiment will be described by taking as an example the case of cutting the workpiece 62 made of an aluminum alloy. When the circular saw 40 rotating at a required rotational speed is brought close to the workpiece 62, the outermost peripheral portion of the hard tip 48, that is, the PCD sintered body 60 of the cutting edge portion 52 reaches the workpiece 62 earliest (see FIG. 6 (a)). Then, the workpiece 62 is cut by the cutting edge portion 52 and the surface thereof is cut out as chips 64. When the workpiece 62 is further cut, as shown in FIG. 6 (b), the chips 64 are guided by the rake face 60 b of the PCD sintered body 60 and the chip guide surface 56 of the cemented carbide substrate 50 to form a spiral shape. Wrapped around. Then, when the hard tip 48 that has cut the workpiece 62 is separated from the workpiece 62, as shown in FIG. 6C, the spirally wound chips 64 are detached from the workpiece 62, It is smoothly discharged to the outside of the circular saw 40.

  Here, in the circular saw 40 according to the first embodiment, the rake face 60b, which is the part that contributes most to the cutting in the hard tip 48, is harder than the cemented carbide and has extremely excellent wear resistance. It is formed by. Therefore, compared to a conventional circular saw that does not use the PCD sintered body 60, wear due to use is extremely small, and the product life can be greatly extended. The PCD sintered body 60 is more expensive than a general cemented carbide material. However, in the circular saw 40 according to the first embodiment, the PCD sintered body 60 is pinpointed only at a portion where the wear is most severe. Therefore, the usage amount of the PCD sintered body 60 can be minimized. Thereby, it becomes possible to suppress the increase in the product cost of the circular saw 40 as much as possible.

  In Example 1, the case where both the cemented carbide substrate 50 and the substrate 58 are formed from the same cemented carbide (WC sintered body) is shown. Good. Further, in the first embodiment, the case where the discharge wire cutting method is adopted when the cutting edge portion 52 and the cemented carbide substrate 50 are molded is shown. However, for example, the cutting may be performed by a laser cutting device or the like. Good. Further, the concave portion 54 and the chip guiding surface 56 of the cemented carbide substrate 50 can be formed by die sintering in addition to the above method. In the first embodiment, the PCD sintered body 60 is used as the ultra-hard sintered body. However, a boron nitride (CBN) sintered body can also be used.

Next, Embodiment 2 to which the invention according to claim 2 of the present invention corresponds will be described below. In the above-described first embodiment, the PCD sintered body 60 is employed as the ultra-hard sintered body and the circular saw 40 suitable for cutting non-ferrous metal such as aluminum alloy has been described. However, the iron-based metal material is cut. In this case, it is recommended to adopt a cubic boron nitride (CBN) sintered body as the ultra-hard sintered body. FIG. 7 shows an enlarged part of a circular saw 72 according to the second embodiment that employs the CBN sintered body 70. The circular saw 72 is basically configured in the same manner as the circular saw 40 of the first embodiment, and a concave portion 54 is formed in a cemented carbide substrate 50 of a hard tip 76 brazed to each tooth body 44. The blade edge portion 82 is joined to the recess 54. The CBN sintered body 70 that forms the first rake face 70b ₁ is provided on the front side of the cutting edge portion 82. That is, in the circular saw 72 of the second embodiment, the outermost peripheral portion of the hard tip 76 is formed by the CBN sintered body 70.

The first rake face 70b ₁ is set to a negative rake angle, like the first rake face 22 described in the prior art. Further, a second rake face 70b ₂ and a chip guide face 56 are formed on the front face 76a in the rotational direction of the hard chip 76. The second rake face 70b ₂ is provided below the first rake face 70b ₁ (on the saw center side) and is set to a positive rake angle. That is, in the circular saw 72 according to the second embodiment, the rake face 70b of the two first rake face 70b ₁ and the second rake face 70b ₂ by the hard tip 76 is formed. In addition, at least the first rake face 70 b ₁ of the rake face 70 b is configured by the CBN sintered body 70. Further similarly to the circular saw 40 shown in Example 1, the second rake face 70b ₂ of the saw center continuously to side chip deflecting surface 56 is formed, a smooth discharge of the chip 64 is realized.

Thus, in the circular saw 72 according to the second embodiment, the first rake face 70b ₁ positioned at least on the outermost peripheral side of the rake face 70b that is the most severely worn part of the hard tip 76 is formed by the CBN sintered body 70. Formed. The CBN sintered body 70 is a polycrystalline sintered body obtained by heating CBN microcrystals under an ultra-high pressure, and is mainly suitably used for cutting difficult-to-cut materials such as heat-resistant steel. The manufacturing process of the cutting edge portion 82 is basically the same as that shown in the first embodiment. However, as is apparent from FIG. 7, the rake angle α of the circular saw 72 according to the second embodiment is as described above. Thus, the negative rake angle (first rake angle) is set to the negative side (negative). That is, when cutting hard iron-based metal, the load applied to the hard tip 76 (blade tip 82) is larger than that of the circular saw 40 of Example 1 that cuts aluminum material or the like, so the rake angle α is made negative. By escaping, the chip resistance of the hard tip 76 is improved. The specific rake angle α is preferably in the range of about 0 ° to 60 °. The thickness dimension L (see FIG. 3) of the CBN sintered body 70 is preferably about 0.2 to 2 mm.

  As described above, in the circular saw 72 according to the second embodiment, the CBN sintered body 70 is used as the ultra-hard sintered body, so that even a difficult-to-cut material such as an iron-based metal is suitably cut. be able to. In addition, since the CBN sintered body 70 is used only in the hardest part of the hard tip 76, the necessary CBN sintered body 70 can be minimized and the product cost of the circular saw 72 is increased. It is suppressed.

In the circular saw 72 according to the second embodiment, the case where the first rake face 70b ₁ is configured by the CBN sintered body 70 that is an ultra-hard sintered body is shown, but in addition to the first rake face 70b ₁ , The second rake face 70b ₂ may also be composed of the CBN sintered body 70. Further, as the ultra-hard sintered body, it is also possible to adopt the polycrystalline diamond (PCD) sintered body shown in Example 1 instead of the CBN sintered body 70.

1 is an overall view showing a circular saw according to Embodiment 1. FIG. It is an enlarged view which shows the tooth body of the circular saw which concerns on Example 1. FIG. FIG. 3 is an enlarged view showing a blade edge part according to the first embodiment. It is the schematic which shows the manufacturing process of a blade edge | tip part, (a) shows a disk-shaped ultrahigh pressure sintered compact blank, (b) shows the division body of the state cut out by predetermined width, (c) is division | segmentation. The cutting edge part cut out from the body is shown. 1 is an enlarged view showing a cemented carbide substrate according to Example 1. FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is an expanded explanatory view which shows a mode that a cut material is cut with the circular saw which concerns on Example 1, Comprising: (a) shows the state which the hard tip contacted the cut material, (b) cuts the cut material (C) shows a state where the hard tip is detached from the work material and spiral chips are discharged. 6 is a partially enlarged view showing a circular saw according to Embodiment 2. FIG. It is a partially enlarged view showing a circular saw having a conventional chip guide surface.

Explanation of symbols

42 Base metal 44 Tooth body 48 Hard tip (Example 1)
48a Front direction of rotation (Example 1)
56 Chip guiding surface 60 PCD sintered body (super hard sintered body)
60b Rake face (Example 1)
62 Work Material 64 Chip 70 CBN Sintered Body (Super Hard Sintered Body)
70b Rake face (Example 2)
70b ₁ First rake face 70b ₂ Second rake face 76 Hard tip (Example 2)
76a Front direction of rotation (Example 2)

Claims (2)

A hard tip (48) is provided on each of the tooth bodies (44) provided on the outer periphery of the base metal (42), and a rake face (60b) is provided on the outer peripheral side of the front surface (48a) in the rotational direction of the hard tip (48). A chip guide surface (56) for guiding the chip (64) of the workpiece (62) to be wound is formed continuously on the saw center side of the rake face (60b) in the hard tip (48). A circular saw,
The outermost peripheral portion of the hard chip (48) made of cemented carbide is formed of a superhard sintered body (60) made of a polycrystalline diamond (PCD) sintered body or a boron nitride (CBN) sintered body, and the rake A circular saw having a chip guiding surface, wherein the surface (60b) is composed of the super-hard sintered body (60). A hard tip (76) is provided on each of a plurality of tooth bodies (44) provided on the outer periphery of the base metal (42), and the first scoop located on the outer peripheral side of the front surface (76a) in the rotational direction of the hard tip (76). A rake face (70b) composed of a face (70b ₁ ) and a second rake face (70b ₂ ) following the first rake face (70b ₁ ) on the saw center side is formed on a hard tip (76), A circular saw formed by a chip guide surface (56) for guiding the chips (64) of (62) to be wound continuously on the saw center side of the second rake face (70b ₂ ) of the hard tip (76). There,
The outermost peripheral portion of the hard chip (76) made of cemented carbide is formed of a super-hard sintered body (70) made of a polycrystalline diamond (PCD) sintered body or a boron nitride (CBN) sintered body, and at least the above-mentioned A circular saw having a chip guiding surface, characterized in that the first rake face (70b ₁ ) is composed of a super-hard sintered body (70).

Images