JPH11197942A - Circular saw equipped with divided peripheral cutting edge part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the use of high-hardness material needed as a cutting tool, by securing respective divided cutting edge part segments and a circular saw barrel plate, with prepared drilling applied to nearly every half respectively, at an aligned surface having a radius direction. SOLUTION: Recessed parts 21 opened toward the center of a circular saw 10 are provided in respective cutting edge part segments 2, in contrast with this, projected parts 11 fitted into the recessed parts 21 of the segments 2 are provided, at given intervals in a circumferential direction, on the outer peripheral edge part of a circular barrel plate 1. Through holes are formed by fitting the respective projected parts 11 of the barrel plate 1 and the recessed parts 21 of the segments 2, to engage first and second engaging projected parts 12 and 22 with each other. The respective segments 2 and the barrel plate 1 are secured by two rivets 3 on an aligned surface having a radius direction, by caulking both the end parts of a rivet 3 inserted into the through holes to engage the large-diameter parts of both the ends of the rivet 3 with a tapered chamfering part respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to steel, non-ferrous metal,
The present invention relates to a circular saw provided with a divided outer peripheral cutting edge portion used for cutting a wood-based or other material.

[0002]

2. Description of the Related Art Conventionally, in the field of circular saws for cutting steel, non-ferrous metals, and wood-based materials, etc., in the cold, first,
In addition, a metal saw (not shown) made of a single steel plate such as a high-speed tool steel used particularly for cutting small-sized materials is known, in which a cutting edge portion having a predetermined shape is integrally formed on an outer peripheral portion of a body plate portion. It was formed. In this metal saw, the shape and pitch (interval between blades) of the cutting edge are usually changed according to the material and dimensions of the material to be cut, and when the blade is worn or chipped, it is ground by grinding. Reshaping had been performed.

Second, especially in the case of a circular saw having a large diameter, as shown in FIGS. 11 and 12, for example, only a cutting edge made of a divided high-speed tool steel is provided on an outer peripheral portion of a body plate (31). The segment saw (30) to which the part (41) is attached has been put to practical use. The segment saw (30) has a cutting edge (41) made of high-speed tool steel with high hardness and excellent wear resistance attached only to the outer periphery of the circular saw body plate (31). Manufacture of circular saw products is possible. In addition, since the expensive material is used only in the outer peripheral portion, the inner body plate (31) does not require the use of an expensive and high-hardness material, and the material cost can be kept relatively low.

Third, as shown in FIG. 13, for example, an outer peripheral ring portion (52) made of an annular hard material having a large number of cutting edges (53) is fitted and integrated with a body plate (51). A circular saw (50) having a different structure has been proposed (see Japanese Patent Application Laid-Open No. 7-178615).

[0005]

However, the first conventional metal saw made of a single plate according to the first aspect is manufactured only from an expensive material that has been heat-treated. Except for the outer peripheral portion used as a cutting edge, It was abandoned without taking advantage of its characteristics as a tool. For this reason, there has been a problem that the material cost is unnecessarily high. Further, such a metal saw can be used until its diameter is reduced to some extent by reshaping, but there is a limit to the minimum diameter that can be used due to the size of the material to be cut and the structure of the cutting machine. In the actual cutting operation, cracks were generated from the vicinity of the blade bottom after several times of reshaping or at a stage where no reshaping was performed, and it was often impossible to reuse. Further, when the diameter of the metal saw is reduced, the peripheral speed of the cutting edge is reduced at the same number of rotations, and the pitch is reduced at the same number of blades. Changes. For this reason, when importance is placed on the cutting accuracy and the life of the cutting edge, the metal saw cannot be used until the diameter of the metal saw becomes too small. As described above, the conventional metal saw made of a single steel plate uses only expensive high-speed tool steel, but it is only used as a cutting edge in a narrow area around the metal saw outer periphery. Therefore, most of them are discarded without being used as cutting edges, and there is a problem that the material is wasted.

Next, in the case of the second conventional segment saw (30) according to the second aspect, the cutting edge segment with the cutting edge (42) is used.
Since expensive materials such as high-speed tool steel are used only for the outer peripheral portion composed of (41), material costs can be kept relatively low, but the body plate (31) and the cutting edge segment (41) Since the joining portion is subjected to machining such as concave and convex fitting, the joining force between the cutting edge segment (41) and the body plate increases,
The processing cost was high and the manufacturing time was long. That is, for example, in the segment saw (30) shown in FIG. 12A, an annular fitting convex part (32) is provided on the outer peripheral edge of the body plate (31), and the rivet insertion hole ( 33), while a fitting recess (4) is provided on the inner edge of each cutting edge segment (41).
4) are provided, these fitting convex part (32) and fitting concave part (44)
Are fitted to each other, and both side walls (43) and (43) of the fitting concave portion (44) are fitted.
The cutting edge segment (41) was attached to the outer peripheral edge of the body plate (31) by a required number of rivets (40) penetrating through the fitting projection (32). On the other hand, in the segment saw (30) shown in FIG. 12B, the fitting recess (34) is formed on the outer peripheral edge of the body plate (31).
On the other hand, a fitting projection (45) having a rivet insertion hole (46) is provided on the inner edge of each cutting edge segment (41), and fitted with these fitting projections (46). The mating concave portion (34) is fitted, and both side walls (35) (35) of the mating concave portion (34) and the mating convex portion
(45) and the required number of rivets (40)
The cutting edge segment (41) was attached to the outer peripheral edge of (31). Further, in the segment saw (30) shown in FIG. 12C, an annular fitting convex portion (37) having a half thickness is provided on the outer peripheral edge of the body plate (31) by so-called collapsing, and this fitting convex portion is provided. (37) is provided with a rivet insertion hole (38), on the other hand, a fitting projection (47) having a half thickness is also provided on the inner edge of each cutting edge segment (41) by mating and piercing, A rivet insertion hole (48) is provided in the fitting protrusion (47), and these fitting protrusions (37) and (47) are overlapped with each other, and both fitting protrusions (37) and (47) The cutting edge segment (41) was attached to the outer peripheral edge of the body plate (31) by a required number of rivets (40) penetrating through. However, in these conventional segment saws (30), the cutting edge segment
(41) and the body plate (31) are connected to each other, which requires high-precision machining, which requires a long manufacturing time and high manufacturing costs. There is a problem that it can be applied only to a large diameter one.

Further, in the case of the circular saw (50) having the third annular high-hardness material outer peripheral ring portion (52) according to the third aspect, the outer peripheral ring portion (52) made of the high-hardness material is integrally formed. Therefore, there is a problem in that the structure is complicated and the manufacturing cost of a portion connected to the body plate 51 increases.

An object of the present invention is to solve the above-mentioned problems of the prior art, to minimize the use of a high-hardness material required as a cutting tool, and to simplify the fastening structure between the outer peripheral cutting edge portion and the body plate portion. Circular saws with a divided outer cutting edge, which can reduce material cost and manufacturing cost, and can sufficiently exhibit cutting performance of high-hardness material, and have extremely excellent cutting performance. There is to try to offer.

[0009]

In order to achieve the above object, a circular saw provided with a divided outer peripheral cutting edge according to the present invention comprises:
The outer peripheral cutting edge portion is a segment structure divided into a plurality of pieces in the circumferential direction, and each of the divided cutting edge portion segments and the circular saw body plate are drilled substantially by half at the mating surface in the radial direction. And are connected by fastening means.

In the present invention, each cutting edge segment is provided with a concave portion which opens toward the center of the circular saw.
On the other hand, on the outer peripheral edge of the body plate, overhanging portions that fit into the concave portions of the segments are provided at predetermined intervals in the circumferential direction, and each overhanging portion of the body plate and the cutting edge portion opposed thereto are provided. Approximately half of each is drilled on the mating surface with the segment.

[0011] In some cases, L-shaped notches are provided at the corners on both sides of the cutting edge segment on the body plate side, as viewed from the front, whereas, on the outer peripheral edge of the body plate, When the ends of adjacent cutting edge segments are abutted against each other, narrow projecting portions that fit in the concave portions formed by the opposed notches are provided at predetermined intervals in the circumferential direction, Approximately half of each of the projecting portions of the body plate and the mating surface of the cutting edge segment facing the projecting portion are drilled.

Further, according to the present invention, each of the divided cutting edge segments and the circular saw body plate are substantially half-prepared and fir-drained on the mating surfaces in the radial direction, respectively. They are connected by fastening means, especially rivets.

In the circular saw according to the present invention, furthermore, even between the divided cutting edge segments, substantially half of each of the drilled surfaces and the countersunk holes are provided on the mating surfaces in the radial direction, and the fastening means is provided. Are connected by

[0014] Thereby, the bonding force is further stabilized and the body plate and each cutting edge segment of the outer peripheral portion are sufficiently fastened, so that even if cutting resistance is generated during the cutting operation, there is no breakage.
Here, the fastening means is, for example, connection with a rivet, bolt, screw, or the like, or connection with a resin.

(Operation) In the circular saw according to the present invention, the cutting edge segment having high hardness and wear resistance, such as a divided high-speed tool steel, is attached to the body plate only in the outer peripheral portion. It is possible to form and use an appropriate blade die according to the material and dimensions of the cutting material. Therefore, when high-speed tool steel is used as the cutting edge segment, cutting performance equivalent to that of a conventional metal saw can be obtained. In addition, by appropriately setting the size of the outer peripheral cutting edge segment, the re-sharpable range can be changed, so that there is no waste of material and economical. Also,
Since the divided cutting edge segment of the outer peripheral portion has a structure with no step in the thickness direction, it can be easily cut from a single steel plate by a laser machine, wire cut electric discharge machine, press, etc. . In addition, since the outer peripheral cutting edge segment is divided into small shapes, even when cut out from a single steel plate, there is little waste of material and it is economical. Further, it is also possible to use an alloy material formed by a powder metallurgy method in which molding is performed using a uniaxial press, which is difficult to manufacture a large product, and sintering is performed. Furthermore, the shape of the mating surface between the cutting edge segment and the body plate, according to curved surface matching, unevenness matching, etc.,
Although the bonding force is more stable, even in such a case, the conventional numerically controlled cutting can be applied, and the degree of design freedom is high. Moreover, the cutting edge segment and the body plate are in contact with each other over the entire thickness, and have sufficient strength to withstand normal cutting resistance even when mild steel rivets or bolts and screws are used.

In the circular saw according to the present invention, each of the divided cutting edge segments and the circular saw body plate are substantially half-prepared at the mating surfaces in the radial direction, and the mild steel rivets, They are connected by fastening means such as bolts or screws. Here, when using a rivet as the fastening means, each of the divided cutting edge portion segments and the circular saw body plate are substantially half-prepared with a drilled hole and a countersink in a radially mating surface. Is rubbed. On the other hand, when a bolt or a bolt / nut is used as the fastening means, each of the divided cutting edge segments and the circular saw body plate are prepared by drilling approximately half each on the mating surface in the radial direction. At the same time, a process of providing a bolt head fitting concave portion, or a bolt head fitting concave portion and a nut fitting concave portion at approximately half the edges of the prepared hole concave portion is performed. Regardless of whether a rivet, a bolt or a screw is used as the fastening means, the recess into which these heads are to be fitted is placed substantially halfway below the radially facing mating surface of the circular saw body plate and the divided cutting edge segment. Provided at the edge of the recess for the hole, the side surface of the joint portion between the circular saw body plate and the cutting edge segment fastened by these fastening means is flat so that the protrusion does not appear on the outer surface. It is necessary to Furthermore, in order to increase the bonding strength of the cutting edge segment with respect to the body plate, between the divided cutting edge segments, the prepared surface and the countersink are applied approximately half each at the mating surface in the radial direction. Are connected by fastening means. As described above, the cutting edge segment and the body plate are fastened with mild steel rivets, bolts, screws, or the like as fastening means, but the cutting edge segment and the body plate are in contact with each other over the entire plate thickness. Therefore, it has a necessary and sufficient bonding strength in a normal cutting operation. In the case of cutting a material having relatively low strength and generating less heat at the time of cutting, it is also possible to use a resin material such as an adhesive instead of the rivet, bolt or screw for fastening. In this case, since there is no problem even if the processing accuracy of the rivet hole is low, the manufacturing cost is reduced and the cost is more economical.

Further, the circular saw according to the present invention does not require high-precision machining like a conventional segment saw,
Not only material costs but also manufacturing costs can be kept low. Further, since the outer peripheral cutting edge segment is divided into small shapes, it is possible to use a powdered high-speed molding material other than high-speed tool steel, or a hard material such as a super hard or a ceramic.

In addition, the segmentation of the circular saw according to the present invention into small segments facilitates coating processing by PVD, CVD processing, etc., and changes the properties such as hardness, toughness, and wear resistance of the cutting edge in accordance with the material to be cut. Can be done.

[0019]

Next, an embodiment of the present invention will be described.
This will be described with reference to the drawings. In each of the drawings, the same portions are denoted by the same reference numerals. 1 to 4 show a first embodiment of the present invention. Referring first to FIGS. 1 and 2,
The circular saw (10) of the present invention is constituted by a high-speed tool segment in which an outer peripheral cutting edge (2) having a cutting edge (20) at a predetermined pitch on an outer peripheral edge is divided into 16 equal parts in a circumferential direction. And
Each of the divided cutting edge segments (2) and the circular saw body plate (1) are substantially half-prepared with a prepared hole and a countersink in a radially mating surface, and rivets are used as fastening means. (3). In addition, a steel plate or the like that is not subjected to heat treatment is used for a body plate (1) portion that fastens most of the circular saw (10). At the center of the circular saw body plate (1), a rotary shaft insertion hole (7) and four bolt holes (8) are formed.

As shown in detail in FIGS. 2 to 4, each cutting edge segment (2) is provided with a concave portion (21) opening toward the center of the circular saw (10). , Circular torso
On the outer peripheral edge of (1), there are provided 16 overhangs (11) at predetermined intervals in the circumferential direction to fit into the recesses (21) of the segment (2). Then, substantially hook-shaped first engagement projections (12) and (12) are provided at both ends of each overhang portion (11), respectively, as viewed from the front,
On the other hand, substantially hook-shaped second engaging projections (22) and (22) are provided on both sides of the opening of the recess (21) of each segment (2) when viewed from the front, respectively. When each overhang portion (11) and the concave portion (21) of the cutting edge segment (2) are fitted together, the first engaging convex portion (12) and the second engaging convex portion (22) are formed. It is designed to be interrelated. The first engaging projections (12) on the side of each body plate overhanging part (11) and the cutting edge segment facing the first engaging projections (12)
(2) On the mating surface with the second engaging convex portion (22) on the side, a pilot hole and a countersink are applied approximately half each, and the rivet fitting concave portions (13) and (23) face each other. Along with the rivet fitting recesses (13) and (23), tapered chamfers (14) tapering toward the center of the plate thickness
(24) are provided respectively. Each overhanging portion (11) of the circular body plate (1) and the recessed portion (21) of the cutting edge segment (2) are fitted together to form a first engaging projection (12) and a second engaging projection. The rivet fitting recesses (13) and (23) form a through-hole when the portion (22) is engaged with the other.
Then, both ends of the rivet (3) inserted through the through hole are swaged, and the large diameter portions (3a) (3a) at both ends of the rivet (3) are engaged with the tapered chamfers (14) (24), respectively. By being combined, each cutting edge segment (2) and circular saw body plate (1)
Are the mating surfaces in the radial direction, and 2
Are connected by two rivets (3) (see FIG. 4a). The connecting portion between each cutting edge segment (2) and the circular saw body plate (1) has an R shape (arc shape) as shown in the figure.
The first engaging projections (12) and the second engaging projections (22) are vertically meshed with each other, so that even if ordinary cutting resistance acts on the plane of the circular saw (10), the cutting edge There is no displacement or breakage of the mounting position of the segment (2). Also, each rivet (3)
Is caulked in the shape of a dish at both ends and rivets (3)
Since the large-diameter portions (3a) and (3a) at both ends are engaged with the tapered chamfers (14) and (24), even if there are some gaps in the meshing portions, the fastening is performed without rattling. Also, during the cutting operation with the circular saw (10), the cutting edge segment (2)
Even if some lateral force is applied to the
It will not be damaged.

Further, in the first embodiment, between the divided cutting edge portion segments (2) and (2),
Drilled holes and countersinks are applied approximately half each on the mating surface in the radial direction, and rivets as fastening means
(3). That is, the connecting end portions (2a) (2a) of the divided cutting edge portion segments (2) (2) which are divided and adjacent to each other are substantially half-prepared and prepared by drilling a dish, and a rivet fitting recess. (25) (25) are provided facing each other, and each rivet recess (25) (25)
On both the front and rear sides, tapered chamfers (26) (26) tapering toward the center of the plate thickness are provided, respectively, and the connection ends of adjacent cutting edge segments (2) (2) ( The through-holes are formed by the rivet fitting recesses (25) and (25) when the parts 2a and 2a are brought into contact with each other.
Then, both ends of the rivet (3) inserted into the through hole are swaged, and the large diameter portions (3a) (3a) at both ends of the rivet (3) are engaged with the tapered chamfers (26) (26), respectively. By joining, the connection end of the adjacent cutting edge segment (2) (2)
(2a) (2a) are joined together by rivets (3) as fastening means at mating surfaces in the radial direction. As described above, the joining surface between the adjacent cutting edge segments (2) and (2) is also joined by the same rivet (3), so that the cutting edge segment (2) (2) The cutting performance of the circular saw (10) is good without causing any twist or step between them. Actually, as shown in FIG. 4b, on both front and rear sides of the cutting edge of the circular saw (10), in particular, the protruding portion (11) of the outer peripheral edge of the circular saw body plate (1) and the cutting edge segment
By tapering the front and rear sides of the part (2) to gradually reduce the thickness toward the center, resistance due to side friction between the cutting edge of the circular saw (10) and the material to be cut is reduced, and cutting is performed. It is more preferable because the life is improved. This point is the same in the following embodiments of the present invention.

As shown in FIG. 5, instead of rivets, bolts (4) are used as fastening members for connecting the respective projecting portions (11) of the circular body plate (1) and the cutting edge segments (2). ) Can be used. In addition, adjacent cutting edge segments
(2) The bolt (4) can also be used as a fastening member for connecting the two. When a bolt (4) is used as a fastening member, each of the divided cutting edge segments (2) and the circular saw body plate (1) are each substantially drilled by a half at the mating surface in the radial direction. It is applied, but the dish fir is not applied. Instead, bolt head fitting recesses (18) are provided by cutting on the front surfaces of both end portions (11a) (11a) of each trunk plate overhanging portion (11). Bolt head fitting recesses (28) are also provided on the front surfaces of the opening side edges (2b) (2b) of the recessed portion (21) of the segment (2). In addition, each overhang (11) of the circular body plate (1) and the cutting edge segment
The through-hole formed by the recesses (13) and (23) for fitting bolts in these mating surfaces is formed as a screw hole (5) (see FIG. 2). 5). In the case where the thickness of the overhang portion (11) of the circular saw (10) and the thickness of the cutting edge segment (2) are small, only the small bolt (4) is connected as shown in FIG. 5A. However, when the plate thickness is large, as shown in FIG. 5B, the use of the small bolts (4) and the nuts (6) provides a stronger coupling force. In the latter case, furthermore, both end portions of each body plate overhang (11)
(11a) On the rear surface of (11a), a nut fitting recess (19) is provided by cutting, and each cutting edge portion segment
Also on the rear surface of the opening side edges (2b) and (2b) of the concave portion (21) of (2),
A nut fitting recess (29) is provided. Also, when using either the rivet (3) or the bolt (4) as the fastening member, it is preferable to prevent the screws from being loosened with an adhesive or the like.

FIGS. 6 and 7 show a second embodiment of the present invention. Here, the point different from the case of the first embodiment is that the outer peripheral cutting edge portion (2) of the circular saw is constituted by high-speed tool segments divided into eight in the circumferential direction. . In addition, both ends of the overhang portion (11) of the body plate (1),
Unlike the case of the first embodiment, the mating surfaces of the joining portions by the rivets (3) at both ends of the concave portion (21) of the cutting edge segment (2) are linear when viewed from the front, but are different from those in the first embodiment. As shown in detail in FIG. 7, each overhang portion (11) of one body plate (1) has a dovetail shape (dovetail shape), and the recess (21) of each other cutting edge segment (2) has this shape. In the dovetail recess that fits, the overhang (11) and the recess (21) are both gradually reduced in width toward the center of the circular saw. There is no displacement of the cutting edge segment (2) in the plane of (10).

FIGS. 8 and 9 show a third embodiment of the present invention. Here, the difference from the case of the first embodiment is that the outer peripheral cutting edge portion (2) of the circular saw is constituted by twelve high-speed tool segments divided in the circumferential direction. It is in the shape of each cutting edge segment (2). That is, each of the cutting edge segments (2) is not provided with the concave portion (21) as in the first embodiment, and instead, the corners on both sides of the cutting edge segment (2) on the body plate side are provided. The part is provided with notches (27) and (27) each having an inverted L shape as viewed from the front. On the other hand, on the outer peripheral edge of the circular body plate (1), the end portions (2a) (2) of the adjacent cutting edge segments (2) (2)
a) When the parts are matched, the two notches facing each other (2
7) Twelve narrow projections (17) are provided at predetermined intervals in the circumferential direction to fit into the concave portions formed by the (27). Both ends of these overhangs (17) of the torso (1),
The straight mating surfaces at the lateral ends of the notches (27) and (27) of the cutting edge segment (2) are joined by rivets (3) in the same manner as in the first embodiment. Such a circular saw (10) according to the third embodiment is useful for cutting relatively low-strength products such as aluminum and copper materials. It is preferable to omit the rivet connection between the adjacent cutting edge segments (2) and (2) because the strength is sufficient and the manufacturing cost can be reduced.

FIG. 10 shows a fourth embodiment of the present invention. The fourth embodiment is obtained by partially combining the first embodiment with the third embodiment. When viewed from the front, corners of both ends of each cutting edge segment (2) on the body plate side are viewed from the front. Inverted L-shaped notches (27) and (27) are provided, and a recess (21) opening toward the center of the circular saw (10) is provided at the center of the cutting edge segment (2). ing.
On the other hand, when the end portions (2a) and (2a) of the adjacent cutting edge segments (2) and (2) abut against the outer peripheral edge of the circular body plate (1), the opposite cutting edges are formed. A narrow overhanging portion (17) that fits into the concave portion formed by the notches (27) and (27),
Wide projections (11) that fit into the recesses (21) of the cutting edge segment (2) are provided alternately at predetermined intervals in the circumferential direction. These overhangs on the bodyboard (1)
Notch (27) and notch (27) in cutting edge segment (2)
(27) The straight mating surfaces at the lateral ends are joined by rivets (3) in the same manner as in the first embodiment, but the concave portions (2) of each cutting edge segment (2) are formed. The both side edges of the opening 21) and the both ends of the wide projecting portion 11 on the side of the body plate 1 fitted to the opening are not connected by rivets 3. However, when each cutting edge segment (2) is more firmly connected to the body plate (1) of the circular saw (10), the opening of the concave portion (21) of each cutting edge segment (2) is required. In some cases, both side edges and both ends of the wide overhanging portion (11) on the side of the body plate (1) are connected by rivets (3). According to the fourth embodiment, an expensive material for forming the cutting edge segment (2) can be further reduced, and the manufacturing cost is reduced.

[0026]

Next, an embodiment of the present invention will be described with reference to the drawings. Examples 1 and 2 A circular saw (10) having the structure of the first embodiment of the present invention shown in FIGS. 1 to 4 was manufactured, and a cutting test was performed. Note that a high-speed tool steel (JIS SKH51 = Example 1) and a powdered high-speed steel material (Example 2) were used as the outer peripheral cutting edge segment (2) divided in the circumferential direction. A normal steel plate (JIS SS400) was used for the circular saw body plate (1), and a mild steel rivet was used for the rivet (3) as a fastening means. 30 mm diameter steel round bar (material: JI
A cutting test was performed using S S45C, hardness: HB180). The size of the circular saw (10) is 315
mm, the blade width was 2.5 mm, and the number of blades was 112 (high / low blade type). The cutting conditions are as follows: rotation speed 21 rpm (peripheral speed: 2)
1 m / min), a feed rate of 140 mm / min, and the presence of cutting oil. In addition, the number of cuts was measured as the life at 0.3 mm wear on the relief surface, the total cost index and the cost index per cut were calculated, and the obtained results are shown in Table 1 below.

Comparative Example 1 For comparison, a cutting test similar to that described above was performed using a conventional metal saw of the same size made of a single plate, and the results obtained are shown in Table 1 below. Shown.

Examples 3 and 4 JIS SCM440H (hardness: H
A cutting test was performed in the same manner as in Examples 1 and 2 except that a steel round bar of RC30) was used, and that the feed rate at the time of rotation of the circular saw (10) was set to 120 mm / min. Done. Similarly, the number of cuts was measured as the life when the wear on the relief surface was 0.3 mm, the total cost index and the cost index per cut were calculated, and the obtained results are shown in Table 2 below.

Comparative Example 2 For comparison, a cutting test similar to that described above was performed using a conventional metal saw of the same size made of a single plate, and the results obtained are shown in Table 2 below. Shown.

[0030]

[Table 1]

[0031]

[Table 2]

As is clear from the results of Tables 1 and 2, the products of the present invention according to Examples 1 to 4 are different from the conventional products.
Reuse by modifying the blade mold is basically a structure that cannot be performed, and although the total number of uses is small, the cost per cut is smaller than the conventional product because the raw material cost and manufacturing cost are small. .

[0033]

According to the circular saw provided with the divided outer peripheral cutting edge portion according to the present invention, the use of expensive materials can be minimized as described above, so that the material cost can be reduced. . Moreover, due to its structure, it has better cutting performance than a conventional circular saw made of a single plate. In addition, when a steel plate or the like that is not subjected to heat treatment is used for a body plate portion for tightening most of the circular saw, there is an advantage that a warp or a bend can be easily corrected because of a moderate elasticity. In addition, the circular saw provided with the divided outer peripheral cutting edge portion according to the present invention does not originally undergo deformation due to heat treatment, so that the manufacturing time is greatly reduced. Furthermore, even when cutting,
It is easy to follow the cutting direction, and diagonal cutting is less likely to occur. In addition, since the divided cutting edge segment of the outer peripheral part has a structure with no step in the thickness direction, it can be easily cut from a single steel plate by a laser cutting machine, wire cut electric discharge machine, press, etc. Can be. Also, since the outer peripheral cutting edge segment is divided into small shapes,
Even when cut out from a single steel plate, there is little waste of material and it is economical. Further, it is also possible to use an alloy material formed by a powder metallurgy method in which molding is performed using a uniaxial press, which is difficult to manufacture a large product, and sintering is performed. Furthermore, according to the shape of the mating surface between the cutting edge segment and the body plate, the bonding force is more stable according to the curved surface matching, the unevenness matching, etc., but even in this case, the conventional numerical control cutting can be applied. There is a high degree of freedom in design. Moreover, the cutting edge segment and the body plate are in contact with each other over the entire thickness, and have sufficient strength to withstand ordinary cutting resistance even with the use of rivets, bolts and screws. In addition, since the outer peripheral cutting edge portion has a segment structure divided into a plurality of pieces in the circumferential direction and is fastened with a minimum necessary binding force by fastening means such as rivets, a force other than the cutting progress direction acts. In this case, it tends to be deformed in a direction to restore the original state. This function also enhances the straightness and makes it difficult to make diagonal cuts. ADVANTAGE OF THE INVENTION According to this invention, the effect that the manufacturing cost of a circular saw can be reduced sharply and the original cutting performance of a circular saw is also improved is produced.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing a circular saw product according to a first embodiment of the present invention.

FIG. 2 is an enlarged front view of a main part of FIG.

FIG. 3a is an enlarged sectional view taken along line AA of FIG. 2; FIG. 3B shows a modification of the circular saw product of the first embodiment, and is an enlarged sectional view of FIG. 3A.

FIG. 4 is an enlarged schematic perspective view of a main part showing a combined state of a divided cutting edge segment of the present invention and a circular saw body plate.

FIG. 5a shows a first example using bolts as fastening means;
FIG. 3b is an enlarged sectional view of the circular saw product of the embodiment, which corresponds to FIG. 3a. FIG. 5b shows bolts as fastening means.
FIG. 3b is an enlarged sectional view of the circular saw product of the first embodiment using a nut, which corresponds to FIG. 3b.

FIG. 6 is a schematic front view showing a circular saw product according to a second embodiment of the present invention.

FIG. 7 is an enlarged front view of a main part of FIG. 6;

FIG. 8 is a schematic front view showing a circular saw product according to a third embodiment of the present invention.

FIG. 9 is an enlarged front view of a main part of FIG. 8;

FIG. 10 is an enlarged front view of a main part of a circular saw product according to a fourth embodiment of the present invention.

FIG. 11 is an enlarged front view of a main part of a conventional circular saw product.

FIG. 12 is an enlarged sectional view taken along the line XX of FIG. 11; FIG. 12a shows a first example of a conventional segment saw, and FIG.
FIG. 12B shows a second example of the conventional segment saw, and FIG. 12C shows a third example of the conventional segment saw.

FIG. 13 is a schematic front view of a conventional circular saw product having an outer peripheral ring portion.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 body plate 2 outer peripheral cutting edge (cutting edge segment) 3 rivet (fastening means) 4 bolt (fastening means) 6 nut 10 circular saw 11 overhang 13 rivet insertion recess 14 chamfer 17 narrow overhang 18 Bolt head fitting recess 19 Nut fitting recess 20 Blade tip 21 Depression 23 Rivet insertion recess 24 Chamfer 25 Rivet insertion recess 26 Chamfer 27 Notch 28 Bolt head insertion recess 29 Nut insertion Recess

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[Procedure amendment]

[Submission date] February 1, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 5

[Correction method] Change

[Correction contents]

Claims (6)

[Claims] 1. A segment structure in which an outer peripheral cutting edge portion is divided into a plurality in the circumferential direction, and each of the divided cutting edge portion segments and a circular saw body plate are joined surfaces in a radial direction,
A circular saw provided with a divided outer peripheral cutting edge portion, wherein substantially half of each is drilled and connected by fastening means. 2. Each of the cutting edge segments is provided with a recess opening toward the center of the circular saw, whereas the outer peripheral edge of the body plate has an overhang fitting with the recess of the segment. Are provided at predetermined intervals in the circumferential direction, and on the mating surface of each overhanging portion of the body plate and the cutting edge segment facing thereto,
The circular saw according to claim 1, wherein a pilot hole is drilled approximately by half. 3. An inverted L-shaped notch as viewed from the front is provided at each of the corners on both sides of the cutting edge segment on the body plate side, whereas adjacent cuts are formed on the outer peripheral edge of the body plate. When the ends of the blade segment are abutted with each other, narrow projections are provided at predetermined intervals in the circumferential direction to fit in the concave portions formed by the opposed notches,
The circular saw according to claim 1, wherein the mating surfaces of the respective projecting portions of the body plate and the cutting edge segments facing the projecting portions are each substantially half pre-drilled. 4. Each of the divided cutting edge segments and the circular saw body plate are substantially half-prepared with a prepared hole and a countersink in a radially mating surface, and are joined by fastening means. A circular saw according to any one of claims 1 to 3. Further, between each of the divided cutting edge segments, substantially half of a prepared hole and a countersink are applied to the mating surface in the radial direction and the mating surface in the radial direction, respectively. The circular saw according to claim 1, wherein the circular saw is connected by fastening means. 6. The circular saw according to claim 1, wherein the fastening means is a connection using a rivet, a bolt or a screw, or a connection using a resin.