Circular saw blade

Abstract

A circular saw blade (1) comprises a disk-shaped metal base (2). The circular saw blade (1) comprises a plurality of gullets (10) recessed in the outer periphery (2b) of the metal base (2). The circular saw blade (1) comprises a plurality of tips (5) joined to the outer periphery (2b) of the metal base (2). The plurality of gullets (10) include deep gullets (11) having a gullet depth (11a) of 1.13 to 1.60 times the average gullet depth. The plurality of gullets (10) include shallow gullets (12) having a gullet depth (12a) of 0.60 to 0.95 times the average gullet depth. The circular saw blade (1) has a deep region (14) that includes only 2-3 consecutive deep gullets (11) and a shallow region (15) that includes only 2-7 consecutive shallow gullets (12).

Description

Circular saw blade

[0001] The present disclosure relates to a circular saw blade used for cutting, for example, wood, wood-based materials, synthetic resin materials, steel materials, non-ferrous metals, and the like.

[0002] Conventionally, circular saw blades have been provided in which multiple tips are bonded to the outer periphery of a disk-shaped base metal. Circular saw blades are used for cutting materials such as wood, wood-based materials, resin materials, and non-ferrous metals such as aluminum. When the circular saw blade is rotated, the cutting edges of each tip sequentially cut the workpiece to form grooves, thereby cutting the workpiece. Blade bodies that protrude radially outward and to which the tips are bonded are provided on the outer periphery of the base metal. Tooth chambers are provided between the blade bodies in the circumferential direction.

[0003] Cutting vibrations occur when cutting a workpiece with a circular saw blade. Because cutting vibrations affect the finished surface of the workpiece, it is desirable to be able to reduce cutting vibrations. Various structures for reducing cutting vibrations have been proposed in the past. JP6472875B describes a structure for reducing cutting vibrations by providing deep tooth chambers in the circumferential direction among multiple tooth chambers arranged in the circumferential direction.

[0004] However, with the previously proposed structures, it was difficult to reduce cutting vibrations that occurred over a wide range of rotational speeds, from low to high. For example, under conditions of high cutting resistance, the amplitude of high-frequency cutting vibrations increases. The increased high-frequency cutting vibrations form fine scale patterns on the cut surface, reducing the quality of the finished surface. This high frequency is affected by the tooth shape of the circular saw blade and occurs at a certain rotational speed within the range of rotational speeds, from low to high. The inventor's extensive research revealed that it was difficult to reduce cutting vibrations over a wide range of rotational speeds with the conventional structures. Therefore, there was room for improvement to reduce high-frequency cutting vibrations over a wide range of rotational speeds.

[0005] Therefore, there has been a need to provide a circular saw blade that can reduce cutting vibrations over a wide range of rotation speeds.

[0006] According to one aspect of the present disclosure, a circular saw blade has a disk-shaped base metal. The circular saw blade has a plurality of tooth chambers recessed into the outer periphery of the base metal. The circular saw blade has a plurality of tips joined to the outer periphery of the base metal. The plurality of tooth chambers includes deep tooth chambers having a tooth chamber depth of 1.13 to 1.60 times the average tooth chamber depth. The plurality of tooth chambers includes shallow tooth chambers having a tooth chamber depth of 0.60 to 0.95 times the average tooth chamber depth. The circular saw blade has a deep region including only 2 to 3 consecutive deep tooth chambers and a shallow region including only 2 to 7 consecutive shallow tooth chambers.

[0007] This reduces cutting vibrations over a wide range of rotational speeds. For example, cutting vibrations caused by the vibrations of adjacent blades in the circumferential direction can also be reduced over a wide range of rotational speeds. This allows the quality of the cut surface of the workpiece to be maintained at a high level over a wide range of rotational speeds. The tooth space depth is the difference between the radius of the outermost periphery of the cutting edge and the radius of the tooth bottom (the position of the tooth space closest to the center of the rotational axis of the circular saw blade), with the axis of rotation of the circular saw blade as the center.

[0008] According to another feature of the present disclosure, a slit-equipped tooth chamber, which is connected to a tooth chamber by a slit, is adjacent to a deep region. The slit-equipped tooth chamber is adjacent to two to three consecutive deep tooth chambers in the deep region. The slit-equipped tooth chamber has properties closer to those of a deep tooth chamber than to those of a shallow tooth chamber due to the presence of the slit. Therefore, the slit-equipped tooth chamber can contribute to reducing cutting vibration as part of the deep region. This can enhance the effect of reducing cutting vibration over a wide range of rotation speeds.

[0009] According to another feature of the present disclosure, deep and shallow regions are alternately arranged. Therefore, no more than four deep tooth chambers are consecutive. No more than eight shallow tooth chambers are consecutive. If there are many consecutive tooth chambers with the same tooth chamber depth, the effect of suppressing cutting vibrations will be weakened. By controlling the number of consecutive deep or shallow tooth chambers, cutting vibrations caused by vibrations of each circumferentially adjacent blade body can be reduced over a wide range of rotation speeds.

[0010] According to another feature of the present disclosure, at least one of the deep tooth chambers is replaced with a slotted tooth chamber, in which a slit is connected to the tooth chamber. The difference between the radius of the axial end of the slit and the radius of the outermost periphery of the cutting edge is 1.3 to 2.0 times the average tooth chamber depth. The slotted tooth chamber has the same effect as the deep tooth chamber in reducing cutting vibration over a wide range of rotation speeds. Therefore, even when at least one of the deep tooth chambers is replaced with a slotted tooth chamber, cutting vibration can be reduced over a wide range of rotation speeds.

[0011] 1 is a side view of a circular saw blade according to a first embodiment; 2 is a partially enlarged top view of a circular saw blade; 3 is a front view of a tip of the circular saw blade; 4 is a partially enlarged side view of a circular saw blade; 5 is a side view of a circular saw blade according to a second embodiment; 6 is a partially enlarged side view of a circular saw blade according to a third embodiment; 7 is a partially enlarged side view of a circular saw blade according to a fifth embodiment; 8 is a partially enlarged side view of a circular saw blade according to a sixth embodiment; 9 is a partially enlarged side view of a circular saw blade according to a seventh embodiment; 10 is a partially enlarged side view of a circular saw blade according to a tenth embodiment; 11 is a partially enlarged side view of a circular saw blade according to a first comparative example; 12 is a partially enlarged side view of a circular saw blade according to a second comparative example; 13 is a partially enlarged side view of a circular saw blade according to a third comparative example; 14 is a photograph showing a cut surface made by the circular saw blade of the first embodiment; 15 is a photograph showing a cut surface made by the circular saw blade of the third embodiment; 16 is a photograph showing a cut surface made by the circular saw blade of the fourth embodiment. 1 is a photograph showing a cut surface made by the circular saw blade of Example 5. FIG. 1 is a photograph showing a cut surface made by the circular saw blade of Example 6. FIG. 1 is a photograph showing a cut surface made by the circular saw blade of Example 10. FIG. 1 is a photograph showing a cut surface made by the circular saw blade of Example 1 Comparative Example. FIG. 1 is a photograph showing a cut surface made by the circular saw blade of Example 2 Comparative Example. FIG. 1 is a photograph showing a cut surface made by the circular saw blade of Example 3 Comparative Example. FIG. 2 is a graph showing the evaluation and Rz of the cut surface made by the circular saw blade of Example 1. FIG. 3 is a graph showing the evaluation and Rz of the cut surface made by the circular saw blade of Example 3. FIG. 4 is a graph showing the evaluation and Rz of the cut surface made by the circular saw blade of Example 5. FIG. 5 is a graph showing the evaluation and Rz of the cut surface made by the circular saw blade of Example 6. FIG. 6 is a graph showing the evaluation and Rz of the cut surface made by the circular saw blade of Example 1 Comparative Example. FIG. 7 is a graph showing the evaluation and Rz of the cut surface made by the circular saw blade of Example 3 Comparative Example. 11. A side view of a circular saw blade according to Example 11. 12. A side view of a circular saw blade according to Example 13. 13. A side view of a circular saw blade according to Example 4 Comparative Example. 14. A photograph showing a cut surface made by the circular saw blade of Example 11. 15. A photograph showing a cut surface made by the circular saw blade of Example 12. 16. A photograph showing a cut surface made by the circular saw blade of Example 13.10 is a photograph showing the cut surface made by the circular saw blade of the fourth comparative example. 11 is a photograph showing the cut surface made by the circular saw blade of the fifth comparative example. 12 is a graph showing the evaluation and Rz of the cut surface made by the circular saw blade of the eleventh example. 13 is a graph showing the evaluation and Rz of the cut surface made by the circular saw blade of the thirteenth example. 14 is a graph showing the evaluation and Rz of the cut surface made by the circular saw blade of the fourth comparative example. 15 is a graph showing the evaluation and Rz of the cut surface made by the circular saw blade of the fifth comparative example. 16 is a table showing the evaluation and Rz of the cut surface made by the circular saw blade of each example and each comparative example.

[0012] One embodiment of the present disclosure will be described with reference to FIG. 1 . The same reference numerals throughout the description refer to the same elements having the same functions, although the same description will not be repeated. As shown in FIG. 1 , a circular saw blade 1 includes a disk-shaped base 2 and a plurality of tips 5 bonded to the outer periphery 2b of the base 2. By rotating the base 2, the cutting edges 5c of each tip 5 (see FIGS. 2 and 3 ) form grooves in the workpiece, thereby cutting the workpiece. Examples of workpiece materials include wood, wood board, and other wood-based materials; synthetic resin materials; ceramic materials; steel materials, such as carbon steel, general structural rolled steel, chromium-molybdenum steel, stainless steel, and cast iron; and non-ferrous metals, such as aluminum, aluminum alloys, copper, and copper alloys.

[0013] As shown in FIG. 1 , a substantially circular mounting hole 2a is provided in the center of the base metal 2, penetrating the base metal 2 in the thickness direction. The rotating shaft of a circular saw cutting machine is inserted into the mounting hole 2a. The circular saw blade 1 rotates clockwise in the figure to cut a workpiece. The outer diameter of the circular saw blade 1 is, for example, 200 mm to 800 mm, e.g., 355 mm. The base metal 2 is made of steel, such as alloy tool steel. The blade thickness of the circular saw blade 1 corresponds to the thickness 5d of the tip 5 (see FIG. 2 ), and is, for example, 0.8 mm to 5.0 mm, e.g., 2.0 mm. The disk-shaped base metal 2 has multiple blade bodies 3 protruding radially outward from the outer periphery 2b. The multiple blade bodies 3 are formed at regular intervals around the circumferential direction of the base metal 2. The thickness 2c of the base metal 2 is slightly smaller than the thickness 5d of the tip 5. The thickness 2c is, for example, 0.6 to 4.5 mm, for example, 1.5 mm (see FIG. 2).

[0014] 2 and 3, the tip 5 includes a first tip 6 and a second tip 7 which have different configurations. The first tips 6 and the second tips 7 are joined alternately at predetermined intervals in the circumferential direction of the base metal 2. The first tips 6 and the second tips 7 alternately reach the workpiece to cut it in parts.

[0015] As shown in Figure 1, the base metal 2 is provided with a plurality of slits (external slits) 8 extending radially inward from the tooth chamber 10. The radially inner ends 8a of the slits 8 are curved in a roughly C-shape with a diameter larger than the width of the slits 8. This makes it possible to suppress stress concentration at the ends 8a of the slits 8 and to suppress the occurrence of cracks. Inside the base metal 2, internal slits 9 are provided with a wavy, meandering shape.

[0016] As shown in FIG. 4 , the plurality of tooth chambers 10 include deep tooth chambers 11, each having a tooth chamber depth 11a, where the difference between the radius of the outermost periphery of the cutting edge 5c and the radius of the tooth root 10a (the position of the tooth chamber 10 closest to the center of the rotation axis of the circular saw blade 1) is equal to the difference between the radius of the outermost periphery of the cutting edge 5c and the radius of the tooth root 10a. The plurality of tooth chambers 10 include shallow tooth chambers 12, each having a tooth chamber depth 12a, where the difference between the radius of the outermost periphery of the cutting edge 5c and the radius of the tooth root 10a is equal to the difference between the radius of the outermost periphery of the cutting edge 5c and the radius of the tooth root 10a. The tooth chamber depth 11a of the deep tooth chamber 11 is, for example, 1.3 to 2.0 times the tooth chamber depth 12a of the shallow tooth chamber 12, e.g., 1.5 times. For example, the tooth chamber depth 11a of the deep tooth chamber 11 is 11.34 mm, and the tooth chamber depth 12a of the shallow tooth chamber 12 is 7.56 mm. The tooth chamber depth 11a of the deep tooth chamber 11 is, for example, 1.13 to 1.60 times the average tooth chamber depth, e.g., 1.25 times. The tooth chamber depth 12a of the shallow tooth chamber 12 is 0.60 to 0.95 times, for example 0.83 times, the average tooth chamber depth. In this case, the average tooth chamber depth is the sum of the tooth chamber depths divided by the number of tooth chambers 10.

[0017] 4, when the tooth chamber depth 11a of the deep tooth chamber 11 is 1.3 times or 2.0 times the tooth chamber depth 12a of the shallow tooth chamber 12, the tooth chamber depth 11a of the deep tooth chamber 11 is 1.16 times or 1.43 times the average tooth chamber depth. When the tooth chamber depth 11a of the deep tooth chamber 11 is 1.3 times or 2.0 times the tooth chamber depth 12a of the shallow tooth chamber 12, the tooth chamber depth 12a of the shallow tooth chamber 12 is 0.89 times or 0.71 times the average tooth chamber depth.

[0018] As shown in Figures 1 and 4, the tooth chambers 10 each have a tooth chamber row 13 consisting of a combination of deep tooth chambers 11 and shallow tooth chambers 12. The tooth chamber rows 13 are repeatedly arranged in the circumferential direction. The tooth chamber row 13 includes a deep region 14 in which two deep tooth chambers 11 are lined up consecutively in the circumferential direction. The tooth chamber row 13 also includes a shallow region 15 in which three shallow tooth chambers 12 are lined up consecutively in the circumferential direction. The deep regions 14 and shallow regions 15 are alternately arranged in the circumferential direction. The tooth chamber row 13 is provided with a total of five tooth chambers 10, consisting of two deep tooth chambers 11 and three shallow tooth chambers 12. The 100 tooth chambers 10 are provided by repeating 15 to 25 sets, specifically 20 sets, of tooth chamber rows 13.

[0019] As shown in FIG. 4 , the slit 8 is provided near the tooth bottom 10 a of the shallow tooth chamber 12 adjacent to the deep region 14 rearward in the rotational direction. This shallow tooth chamber 12 is the slotted tooth chamber 16 in which the slit 8 is provided in the present disclosure. The circular saw blade has five slotted tooth chambers 16. Each slotted tooth chamber 16 is provided at five equal positions in the circumferential direction. The slotted tooth chamber 16 has a tip depth 16 a that includes the slit 8. The tip depth 16 a is the difference between the radius of the outermost periphery of the cutting edge 5 c and the radius of the end 8 a of the slit 8 on the axial side. The tip depth 16 a is, for example, 5 mm to 50 mm, and is, for example, 25 mm.

[0020] 4, when the tooth chamber depth 11a of the deep tooth chamber 11 is 1.3 times the tooth chamber depth 12a of the shallow tooth chamber 12, the tip depth 16a of the slit tooth chamber 16, which is considered to be the tooth chamber depth, is 1.3 to 8.0 times, 2 to 3 times, for example, 2.68 times the average tooth chamber depth with slits. Note that the average tooth chamber depth with slits is larger than the average tooth chamber depth described above because the slit depth is taken into account.

[0021] As described above, the circular saw blade 1 has a disk-shaped base metal 2 as shown in FIGS. 1 and 4. The circular saw blade 1 has a plurality of tooth chambers 10 recessed into the outer periphery 2b of the base metal 2. The circular saw blade 1 has a plurality of tips 5 joined to the outer periphery 2b of the base metal 2. The plurality of tooth chambers 10 include deep tooth chambers 11 having a tooth chamber depth 11a that is 1.13 to 1.60 times the average tooth chamber depth. The plurality of tooth chambers 10 include shallow tooth chambers 12 having a tooth chamber depth 12a that is 0.60 to 0.95 times the average tooth chamber depth. The circular saw blade 1 has a deep region 14 that includes only two to three consecutive deep tooth chambers 11 and a shallow region 15 that includes only two to seven consecutive shallow tooth chambers 12.

[0022] This reduces cutting vibrations over a wide range of rotation speeds. For example, cutting vibrations caused by vibrations of adjacent blade bodies 3 in the circumferential direction can also be reduced over a wide range of rotation speeds. This allows the quality of the cut surface of the workpiece to be maintained at a high level over a wide range of rotation speeds.

[0023] 1 and 4, the slitted tooth chamber 16, which is connected to the tooth chamber 10 by the slit 8, is adjacent to the deep region 14. The slitted tooth chamber 16 is further connected to two adjacent deep tooth chambers 11 in the deep region 14. This enhances the effect of reducing cutting vibrations over a wide range of rotation speeds.

[0024] As shown in Figures 1 and 4, deep regions 14 and shallow regions 15 are arranged alternately. Therefore, no more than four deep tooth chambers 11 are consecutive. No more than eight shallow tooth chambers 12 are consecutive. If there are a large number of consecutive tooth chambers 10 with the same tooth chamber depth 11a or tooth chamber depth 12a, the effect of suppressing cutting vibrations will be weakened. By controlling the number of consecutive deep tooth chambers 11 or shallow tooth chambers 12, cutting vibrations caused by vibrations of adjacent cutting elements in the circumferential direction can be reduced over a wide range of rotational speeds.

[0025] As shown in Figure 4, the tooth chamber 10 adjacent to the deep region 14 is connected to the slit 8, and the tip depth 16a is greater than 1.3 times and less than 8.0 times the average tooth chamber depth. Therefore, the tip depth 16a including the slit 8 is sufficiently longer than the average tooth chamber depth. Moreover, the tooth chamber 10 including the slit 8 has the same effect on cutting vibration as the deep tooth chamber 11, and by connecting to the deep region 14, it is possible to further enhance the effect of reducing cutting vibration over a wide range of rotation speeds.

[0026] Next, a second embodiment of the present disclosure will be described with reference to Fig. 5. A circular saw blade 20 of the second embodiment has a tooth chamber row 21 instead of the tooth chamber row 13 shown in Fig. 1. In the following description, only the parts that differ from the first embodiment will be described in detail.

[0027] As shown in Figure 5, the tooth chamber row 21 includes a deep region 22 in which deep tooth chambers 11 are provided consecutively, and a shallow region 23 in which shallow tooth chambers 12 are provided consecutively. The tooth chamber row 21 is provided with a first shallow region 23a, a first deep region 22a, a second shallow region 23b, a second deep region 22b, a third shallow region 23c, and a third deep region 22c, in order from the front in the rotational direction, with the shallow regions 23 and deep regions 22 arranged alternately. The first shallow region 23a is provided with seven consecutive shallow tooth chambers 12. The first deep region 22a is provided with two consecutive deep tooth chambers 11. The second shallow region 23b is provided with three consecutive shallow tooth chambers 12. The second deep region 22b is provided with two consecutive deep tooth chambers 11. The third shallow region 23c is provided with three consecutive shallow tooth chambers 12. The third deep region 22c is provided with three consecutive deep tooth chambers 11. The tooth chamber row 21 is provided with a total of 20 tooth chambers 10. The 100 tooth chambers 10 are provided by repeating 2 to 8 sets, specifically 5 sets, of tooth chamber rows 21.

[0028] As shown in FIG. 5, in the circular saw blade 20, the tooth chamber depth 11a (see FIG. 4) of the deep tooth chamber 11 is 1.13 to 1.60 times the average tooth chamber depth, for example, 1.28 times. The tooth chamber depth 12a (see FIG. 4) of the shallow tooth chamber 12 is 0.60 to 0.95 times the average tooth chamber depth, for example, 0.85 times. One shallow tooth chamber 12 in the tooth chamber row 21 is a slotted tooth chamber 16 in which a slit 8 is provided near the tooth bottom. The circular saw blade 20 has five slotted tooth chambers 16. The tip depth 16a (see FIG. 4) of the slotted tooth chamber 16, when considered as the tooth chamber depth, is greater than 1.3 times and less than 8.0 times the average slotted tooth chamber depth, for example, 2.56 times.

[0029] As shown in Figure 5, when the tooth chamber depth 11a of the deep tooth chamber 11 (see Figure 4) in the circular saw blade 20 is 1.3 or 2.0 times the tooth chamber depth 12a of the shallow tooth chamber 12 (see Figure 4), the tooth chamber depth 11a of the deep tooth chamber 11 is 1.18 or 1.48 times the average tooth chamber depth, and the tooth chamber depth 12a of the shallow tooth chamber 12 is 0.90 or 0.74 times the average tooth chamber depth. Furthermore, the tip depth 16a of the slitted tooth chamber 16 (see Figure 4), considered as the tooth chamber depth, is 2 to 3 times the average slitted tooth chamber depth, for example, 2.71 or 2.26 times. The circular saw blade 20 described above provides the same effects as the circular saw blade 1 shown in Figure 1.

[0030] Next, a third embodiment of the present disclosure will be described with reference to Fig. 6. A circular saw blade 30 of the third embodiment has a tooth chamber row 31 instead of the tooth chamber row 13 shown in Fig. 1. In the following description, only the parts that differ from the first embodiment will be described in detail.

[0031] As shown in Figure 6, deep regions 32 and shallow regions 33 are alternately arranged in the tooth chamber row 31 in the circumferential direction. The deep region 32 is formed by two consecutive deep tooth chambers 11. The shallow region 33 is formed by two consecutive shallow tooth chambers 12. The tooth chamber row 31 is formed by a total of four tooth chambers 10. The 100 tooth chambers 10 are formed by repeating 20 to 30 sets, specifically 25 sets, of tooth chamber rows 31. The circular saw blade 30 has five shallow tooth chambers 12 as slit tooth chambers 16. The slit tooth chambers 16 are adjacent to the deep region 32 on the front side in the rotational direction.

[0032] 6, in the circular saw blade 30, the tooth chamber depth 11a of the deep tooth chamber 11 is 1.13 to 1.60 times the average tooth chamber depth, for example, 1.20 times. The tooth chamber depth 12a of the shallow tooth chamber 12 is 0.60 to 0.95 times the average tooth chamber depth, for example, 0.80 times. The tip depth 16a of the slit tooth chamber 16, when considered as the tooth chamber depth, is more than 1.3 times but not more than 8.0 times the average slit tooth chamber depth, for example, 2.42 times.

[0033] As shown in Figure 6, when the tooth chamber depth 11a of the deep tooth chamber 11 in the circular saw blade 30 is 1.3 times or 2.0 times the tooth chamber depth 12a of the shallow tooth chamber 12, the tooth chamber depth 11a of the deep tooth chamber 11 is 1.13 times or 1.33 times the average tooth chamber depth, and the tooth chamber depth 12a of the shallow tooth chamber 12 is 0.87 times or 0.67 times the average tooth chamber depth. Furthermore, the tip depth 16a of the slotted tooth chamber 16, considered as the tooth chamber depth, is 2 to 3 times the average slotted tooth chamber depth, for example, 2.61 times or 2.05 times. The circular saw blade 30 described above provides the same effects as the circular saw blade 1 shown in Figure 1.

[0034] Next, a fourth embodiment of the present disclosure will be described with reference to Fig. 7. A circular saw blade 40 of the fourth embodiment has a tooth chamber row 43 instead of the tooth chamber row 13 shown in Fig. 1. In the following description, only the parts that differ from the first embodiment will be described in detail.

[0035] As shown in FIG. 7 , deep regions 44 and shallow regions 45 are alternately arranged in the circumferential direction in the tooth chamber row 43. The deep region 44 includes a first deep tooth chamber 41 at the front of the rotational direction and a second deep tooth chamber 42 at the rear of the rotational direction, which are arranged consecutively in the circumferential direction. The shallow region 45 includes three consecutive shallow tooth chambers 12. The tooth chamber row 43 includes a total of five tooth chambers 10. One hundred tooth chambers 10 are provided by repeating 20 sets of tooth chamber rows 43. The circular saw blade 40 includes five shallow tooth chambers 12 as slotted tooth chambers 16. The slotted tooth chambers 16 are adjacent to the deep region 44 at the rear of the rotational direction. The tooth chamber depth 41 a of the first deep tooth chamber 41 is 1.5 times the tooth chamber depth 12 a of the shallow tooth chamber 12. The tooth chamber depth 42 a of the second deep tooth chamber 42 is 1.3 times the tooth chamber depth 12 a of the shallow tooth chamber 12.

[0036] As shown in FIG. 7 , in the circular saw blade 40, the tooth chamber depth 41a of the first deep tooth chamber 41 is 1.13 to 1.60 times the average tooth chamber depth, for example, 1.29 times. The tooth chamber depth 42a of the second deep tooth chamber 42 is 1.13 to 1.60 times the average tooth chamber depth, for example, 1.20 times. The tooth chamber depth 12a of the shallow tooth chamber 12 is 0.60 to 0.95 times the average tooth chamber depth, for example, 0.86 times. The tip depth 16a of the slotted tooth chamber 16, when considered as a tooth chamber depth, is greater than 1.3 times and less than 8.0 times the average slotted tooth chamber depth, for example, 2.59 times. The circular saw blade 40 described above exhibits the same effects as the circular saw blade 1 shown in FIG. 1 .

[0037] Next, a fifth embodiment of the present disclosure will be described with reference to Fig. 8. A circular saw blade 50 of the fifth embodiment has a tooth chamber row 53 instead of the tooth chamber row 43 shown in Fig. 7. In the following description, only the parts that differ from the seventh embodiment will be described in detail.

[0038] As shown in FIG. 8 , deep regions 54 and shallow regions 55 are alternately arranged in the tooth chamber row 53 in the circumferential direction. In the deep region 54, a first deep tooth chamber 51 at the front of the deep region 54 in the rotational direction and a second deep tooth chamber 52 at the rear of the deep region 54 in the rotational direction are arranged consecutively in the circumferential direction. The tooth chamber depth 51a of the first deep tooth chamber 51 and the tooth chamber depth 52a of the second deep tooth chamber 52 are 1.3 times and 1.5 times the tooth chamber depth 12a of the shallow tooth chamber 12, respectively. The shallow region 55 is formed by three consecutive shallow tooth chambers 12. The tooth chamber row 53 is formed by a total of five tooth chambers 10. One hundred tooth chambers 10 are formed by repeating 20 sets of tooth chamber rows 53. The circular saw blade 50 has five shallow tooth chambers 12 adjacent to the rear of the deep region 54 in the rotational direction as slotted tooth chambers 16. The circular saw blade 50 described above provides the same effects as the circular saw blade 40 shown in FIG.

[0039] Next, a sixth embodiment of the present disclosure will be described with reference to Fig. 9. A circular saw blade 60 of the sixth embodiment has a tooth chamber row 62 instead of the tooth chamber row 13 shown in Fig. 1. In the following description, only the parts that differ from the first embodiment will be described in detail.

[0040] As shown in FIG. 9 , the tooth chamber depth 61a of the deep tooth chamber 61 is 1.3 times the tooth chamber depth 12a of the shallow tooth chamber 12. In the circular saw blade 60, the tooth chamber depth 61a of the deep tooth chamber 61 is 1.13 to 1.60 times the average tooth chamber depth, for example, 1.16 times. The tooth chamber depth 12a of the shallow tooth chamber 12 is 0.60 to 0.95 times the average tooth chamber depth, for example, 0.89 times. The tip depth 16a of the slotted tooth chamber 16, when considered as a tooth chamber depth, is greater than 1.3 times and less than 8.0 times the average slotted tooth chamber depth, for example, 2.68 times. The circular saw blade 60 described above exhibits the same effects as the circular saw blade 1 shown in FIG. 1 .

[0041] Next, a seventh embodiment of the present disclosure will be described with reference to Fig. 10. A circular saw blade 70 of the seventh embodiment has a tooth chamber row 73 instead of the tooth chamber row 13 shown in Fig. 1. In the following description, only the differences from the first embodiment will be described in detail. The circular saw blade 70 has slit tooth chambers 16 connected by short slits 72 near the tooth bottoms 71a, instead of the multiple deep tooth chambers 11 shown in Fig. 4.

[0042] As shown in FIG. 10 , the circular saw blade 70 has 100 tooth chambers 71. The tooth chambers 71 are provided with a tooth chamber depth 71b that is the difference between the radius of the outermost periphery of the cutting edge 5c and the radius of the tooth root 71a. In the tooth chamber row 73, deep regions 74 and shallow regions 75 are arranged alternately in the circumferential direction. The deep region 74 is formed by two consecutive slit tooth chambers 16. The shallow region 75 is formed by three consecutive tooth chambers 71. The tooth chamber row 73 is formed by a total of five tooth chambers 71. The 100 tooth chambers 71 are provided by repeating 20 sets of tooth chamber rows 73.

[0043] As shown in FIG. 10 , the slit 72 extends radially inward from the tooth chamber 71. The radially inner end 72a of the slit 72 is curved in a generally C-shape with a diameter larger than the width of the slit 72. The tip depth 16a of the slotted tooth chamber 16 is the difference between the radius of the outermost periphery of the cutting edge 5c and the radius of the radially inner end 72a of the slit 72. The tip depth 16a is 1.3 to 2.0 times the tooth chamber depth 71b of the tooth chamber 71, for example, 1.5 times. When the tip depth 16a of the slotted tooth chamber 16 in the circular saw blade 70 is considered to be the tooth chamber depth, it is 1.13 to 1.60 times the average tooth chamber depth with the slit, for example, 1.25 times. When the tip depth 16a is considered to be the tooth chamber depth, the tooth chamber depth 71b of the tooth chamber 71 is 0.60 to 0.95 times the average tooth chamber depth with the slit, for example, 0.83 times.

[0044] The circular saw blade 70 described above achieves the same effects as the circular saw blade 1 shown in FIG. 1 . Furthermore, as shown in FIG. 10 , at least one of the deep tooth chambers is replaced with a slotted tooth chamber 16, in which a slit 72 connects to the tooth chamber 71. The tip depth 16a of the slotted tooth chamber 16, i.e., the difference between the radius of the axial end 72a of the slit 72 and the radius of the outermost periphery of the cutting edge 5c, is 1.3 to 2.0 times the average tooth chamber depth. The slotted tooth chamber 16 achieves the same effect as the deep tooth chamber in reducing cutting vibrations over a wide range of rotational speeds. Therefore, even when at least one of the deep tooth chambers is replaced with the slotted tooth chamber 16, cutting vibrations can be reduced over a wide range of rotational speeds.

[0045] Next, an eighth embodiment of the present disclosure is shown in FIG. 11. In a circular saw blade 80 of the eighth embodiment, the slit 72 shown in FIG. 10 is replaced with a slit 82. The slit 82 extends radially inward from the tooth chamber 81. A radially inner end 82a of the slit 82 is provided as a circular hole with a diameter larger than the width of the slit 82. The circular saw blade 80 described above provides the same effects as the circular saw blade 1 shown in FIG. 1 and the circular saw blade 70 shown in FIG. 10.

[0046] Next, a ninth embodiment of the present disclosure is shown in FIG. 12 . In the circular saw blade 90 of the ninth embodiment, the slit 72 shown in FIG. 10 is replaced with a slit 92. The slit 92 extends radially inward from the tooth chamber 91. The width of the slit 92 is narrower than the circumferential width of the tooth chamber 91 (the width passing through the outermost point of the base metal in the area where chips are mainly accommodated), for example, 1 / 3 to 1 / 20 of the circumferential width of the tooth chamber 91, e.g., 1.5 mm. The radially inner end 92a of the slit 92 is formed in a semicircular shape with a diameter substantially equal to the width of the slit 92. The circular saw blade 90 described above achieves the same effects as the circular saw blade 1 shown in FIG. 1 and the circular saw blade 70 shown in FIG. 10 .

[0047] Next, a tenth embodiment of the present disclosure is shown in Figure 13. In the circular saw blade 100 of the tenth embodiment, the slit 8 shown in Figure 1 is disposed in the shallow tooth chamber 12 that is not adjacent to the deep tooth chamber 11. The circular saw blade 100 described above provides the same effects as the circular saw blade 1 shown in Figure 1.

[0048] Next, an eleventh embodiment of the present disclosure will be described with reference to Fig. 34. A circular saw blade 140 of the eleventh embodiment has a tooth chamber row 141 instead of the tooth chamber row 13 shown in Fig. 1. In the following description, only the parts that differ from the first embodiment will be described in detail.

[0049] As shown in FIG. 34 , deep regions 142 and shallow regions 143 are alternately arranged in the circumferential direction in the tooth chamber row 141. The deep region 142 is formed by two consecutive deep tooth chambers 11. The shallow region 143 is formed by two consecutive shallow tooth chambers 12. The tooth chamber row 141 is formed by a total of four tooth chambers 10. The 96 tooth chambers 10 are provided by repeating 20 to 30 sets, specifically 24 sets, of tooth chamber rows 141. The circular saw blade 140 has four shallow tooth chambers 12 as slit tooth chambers 16. Each slit tooth chamber 16 is provided at a position that divides the outer periphery 2b of the base metal 2 into four equal parts in the circumferential direction. The slit tooth chambers 16 are adjacent to the deep region 142 on the front side in the rotational direction.

[0050] As shown in Figure 34, the tooth chamber depth 11a (see Figure 4) of the deep tooth chamber 11 in the circular saw blade 140 is 1.13 to 1.60 times the average tooth chamber depth, for example, 1.20 times. The tooth chamber depth 12a (see Figure 4) of the shallow tooth chamber 12 in the circular saw blade 140 is 0.60 to 0.95 times the average tooth chamber depth, for example, 0.80 times. The tip depth 16a (see Figure 4) of the slit tooth chamber 16 in the circular saw blade 140, when considered as a tooth chamber depth, is more than 1.3 times and 8.0 times or less the average slit tooth chamber depth, for example, 2.46 times.

[0051] As shown in Figure 34, when the tooth chamber depth 11a of the deep tooth chamber 11 (see Figure 4) in the circular saw blade 140 is 1.3 or 2.0 times the tooth chamber depth 12a of the shallow tooth chamber 12 (see Figure 4), the tooth chamber depth 11a of the deep tooth chamber 11 is 1.13 or 1.33 times the average tooth chamber depth, and the tooth chamber depth 12a of the shallow tooth chamber 12 is 0.87 or 0.67 times the average tooth chamber depth. Furthermore, the tip depth 16a of the slitted tooth chamber 16 (see Figure 4), considered as the tooth chamber depth, is 2 to 3 times the average slitted tooth chamber depth, for example, 2.65 or 2.07 times. The circular saw blade 140 described above provides the same effects as the circular saw blade 1 shown in Figure 1.

[0052] Next, a twelfth embodiment of the present disclosure will be described with reference to Fig. 35. A circular saw blade 150 of the twelfth embodiment has a tooth chamber row 151 instead of the tooth chamber row 13 shown in Fig. 1. In the following description, only the parts that differ from the first embodiment will be described in detail.

[0053] As shown in Figure 35, deep regions 152 and shallow regions 153 are alternately arranged in the circumferential direction in the tooth chamber row 151. The deep region 152 is formed by two consecutive deep tooth chambers 11. The shallow region 153 is formed by four consecutive shallow tooth chambers 12. The tooth chamber row 151 is formed by a total of six tooth chambers 10. The 96 tooth chambers 10 are provided by repeating 10 to 20 sets, specifically 16 sets, of tooth chamber rows 151. The circular saw blade 150 has four shallow tooth chambers 12 as slit tooth chambers 16. The slit tooth chambers 16 are adjacent to the deep region 152 on the front side in the rotational direction.

[0054] As shown in Figure 35, the tooth chamber depth 11a (see Figure 4) of the deep tooth chamber 11 in the circular saw blade 150 is 1.13 to 1.60 times the average tooth chamber depth, for example, 1.29 times. The tooth chamber depth 12a (see Figure 4) of the shallow tooth chamber 12 in the circular saw blade 150 is 0.60 to 0.95 times the average tooth chamber depth, for example, 0.86 times. The tip depth 16a (see Figure 4) of the slit tooth chamber 16 in the circular saw blade 150, when considered as the tooth chamber depth, is more than 1.3 times and 8.0 times or less the average slit tooth chamber depth, for example, 2.62 times.

[0055] As shown in Figure 35, when the tooth chamber depth 11a of the deep tooth chamber 11 (see Figure 4) in the circular saw blade 150 is 1.3 or 2.0 times the tooth chamber depth 12a of the shallow tooth chamber 12 (see Figure 4), the tooth chamber depth 11a of the deep tooth chamber 11 is 1.18 or 1.50 times the average tooth chamber depth, and the tooth chamber depth 12a of the shallow tooth chamber 12 is 0.91 or 0.75 times the average tooth chamber depth. Furthermore, the tip depth 16a of the slitted tooth chamber 16 (see Figure 4), considered as the tooth chamber depth, is 2 to 3 times the average slitted tooth chamber depth, for example, 2.76 or 2.31 times. The circular saw blade 150 described above provides the same effects as the circular saw blade 1 shown in Figure 1.

[0056] Next, a thirteenth embodiment of the present disclosure will be described with reference to Fig. 36. A circular saw blade 160 of the thirteenth embodiment has a tooth chamber row 161 instead of the tooth chamber row 13 shown in Fig. 1. In the following description, only the parts that differ from the first embodiment will be described in detail.

[0057] As shown in Figure 36, deep regions 162 and shallow regions 163 are alternately arranged in the circumferential direction in the tooth chamber row 161. The deep region 162 is formed by two consecutive deep tooth chambers 11. The shallow region 163 is formed by six consecutive shallow tooth chambers 12. The tooth chamber row 161 is formed by a total of eight tooth chambers 10. The 96 tooth chambers 10 are formed by repeating 5 to 15 sets, specifically 12 sets of tooth chamber rows 161. The circular saw blade 160 has four shallow tooth chambers 12 as slit tooth chambers 16. The slit tooth chambers 16 are adjacent to the deep region 162 on the front side in the rotational direction.

[0058] As shown in Figure 36, the tooth chamber depth 11a (see Figure 4) of the deep tooth chamber 11 in the circular saw blade 160 is 1.13 to 1.60 times the average tooth chamber depth, for example, 1.33 times. The tooth chamber depth 12a (see Figure 4) of the shallow tooth chamber 12 in the circular saw blade 160 is, for example, 0.60 to 0.95 times the average tooth chamber depth, for example, 0.89 times. The tip depth 16a (see Figure 4) of the slit tooth chamber 16 in the circular saw blade 160, when considered as the tooth chamber depth, is more than 1.3 times but not more than 8.0 times the average slit tooth chamber depth, for example, 2.71 times.

[0059] As shown in Figure 36, when the tooth chamber depth 11a of the deep tooth chamber 11 (see Figure 4) in the circular saw blade 160 is 1.3 times or 2.0 times the tooth chamber depth 12a of the shallow tooth chamber 12 (see Figure 4), the tooth chamber depth 11a of the deep tooth chamber 11 is 1.21 times or 1.60 times the average tooth chamber depth, and the tooth chamber depth 12a of the shallow tooth chamber 12 is 0.93 times or 0.80 times the average tooth chamber depth. Furthermore, the tip depth 16a of the slitted tooth chamber 16 (see Figure 4), considered as the tooth chamber depth, is 2 to 3 times the average slitted tooth chamber depth, for example, 2.82 times or 2.46 times. The circular saw blade 160 described above provides the same effects as the circular saw blade 1 shown in Figure 1.

[0060] For each example of the circular saw blade of the present disclosure, tests were conducted to evaluate the cut surface of the workpiece and measure the surface roughness (maximum height) Rz. The cutting conditions were a thick aluminum workpiece. The rotation speed was changed from 2220 rpm to 4560 rpm in increments of 180 rpm. The feed rate per tooth Fz was 0.01 mm / tooth. The cut surface was evaluated visually based on a three-level rating of ◯, △, or × to determine the presence or absence of scale patterns, etc., and the surface roughness Rz. Tests were also conducted on the first through fifth comparative examples in addition to each example. Below, only the differences between each comparative example and the first example will be described.

[0061] As shown in Figure 14, the circular saw blade 110 of the first comparative example has a tooth chamber row 111. In the tooth chamber row 111, deep regions 112 and shallow regions 113 are arranged alternately in the circumferential direction. The deep region 112 is formed by two consecutive deep tooth chambers 11. The shallow region 113 is formed by eight consecutive shallow tooth chambers 12. Ten sets of tooth chamber rows 111 are repeated in the circumferential direction. The circular saw blade 110 has five shallow tooth chambers 12 as slotted tooth chambers 16. The slotted tooth chambers 16 are adjacent to the deep region 112 on the front side in the rotational direction.

[0062] 14 , when the tooth chamber depth 11a of the deep tooth chamber 11 is 1.3, 1.5, or 2.0 times the tooth chamber depth 12a of the shallow tooth chamber 12 in the circular saw blade 110, the tooth chamber depth 11a of the deep tooth chamber 11 is 1.23, 1.37, or 1.67 times the average tooth chamber depth, and the tooth chamber depth 12a of the shallow tooth chamber 12 is 0.94, 0.91, or 0.82 times the average tooth chamber depth. Furthermore, the tip depth 16a of the slitted tooth chamber 16, considered as the tooth chamber depth, is 2.81, 2.72, or 2.51 times the average slitted tooth chamber depth.

[0063] As shown in FIG. 15 , the circular saw blade 120 of the second comparative example has a tooth chamber row 121. The tooth chamber row 121 includes, from the front in the rotational direction, a shallow tooth chamber 12, a deep tooth chamber 11, a shallow tooth chamber 12, a deep tooth chamber 11, and a shallow tooth chamber 12. The tooth chamber row 121 is composed of a total of five tooth chambers 10. Twenty sets of tooth chamber rows 121 are repeated in the circumferential direction. The circular saw blade 120 has five shallow tooth chambers 12 as slotted tooth chambers 16. The ratios of the tooth chamber depth 11 a of the deep tooth chambers 11, the tooth chamber depth 12 a of the shallow tooth chambers 12, and the tip depth 16 a of the slotted tooth chambers 16, which are considered to be the tooth chamber depth, to the average tooth chamber depth are the same as those of the circular saw blade 1 shown in FIG. 4 .

[0064] As shown in Figure 16, the circular saw blade 130 of the third comparative example has 100 tooth chambers 10 arranged side by side, all of the same tooth chamber depth. The depth of the tooth chambers 10 is the same as the tooth chamber depth 12a of the shallow tooth chambers 12 (see Figure 4). If the tip depth 16a of the slotted tooth chambers 16 is considered to be the tooth chamber depth, the tooth chamber depth of the tooth chambers 10 that are not slotted tooth chambers 16 is 0.90 times the average slotted tooth chamber depth. If the tip depth 16a of the slotted tooth chambers 16 is considered to be the tooth chamber depth, it is 2.96 times the average slotted tooth chamber depth.

[0065] As shown in Figure 37, the circular saw blade 170 of the fourth comparative example has a tooth chamber row 171. In the tooth chamber row 171, deep regions 172 and shallow regions 173 are arranged alternately in the circumferential direction. The deep region 172 is formed by two consecutive deep tooth chambers 11. The shallow region 173 is formed by ten consecutive shallow tooth chambers 12. Eight sets of tooth chamber rows 171 are repeated in the circumferential direction. The circular saw blade 170 has four shallow tooth chambers 12 as slotted tooth chambers 16. The slotted tooth chambers 16 are adjacent to the deep region 172 on the front side in the rotational direction.

[0066] 37, when the tooth chamber depth 11a of the deep tooth chamber 11 (see FIG. 4) of the circular saw blade 170 is 1.3, 1.5, or 2.0 times the tooth chamber depth 12a of the shallow tooth chamber 12 (see FIG. 4), the tooth chamber depth 11a of the deep tooth chamber 11 is 1.24, 1.38, or 1.71 times the average tooth chamber depth, and the tooth chamber depth 12a of the shallow tooth chamber 12 is 0.95, 0.92, or 0.86 times the average tooth chamber depth. Furthermore, the tip depth 16a of the slitted tooth chamber 16 (see FIG. 4), which is considered to be the tooth chamber depth, is 2.89, 2.80, or 2.62 times the average slitted tooth chamber depth.

[0067] The circular saw blade of the fifth comparative example (not shown) is provided with tooth chambers 10 having the same tooth chamber depth 12a, similar to the circular saw blade 130 shown in Figure 16. It differs from the circular saw blade 130 in that it has 96 tooth chambers 10 and four slotted tooth chambers 16. If the tip depth 16a of the slotted tooth chambers 16 is considered to be the tooth chamber depth, the tooth chamber depth of the tooth chambers 10 that are not slotted tooth chambers 16 is 0.91 times the average slotted tooth chamber depth. If the tip depth 16a of the slotted tooth chambers 16 is considered to be the tooth chamber depth, it is 3.02 times the average slotted tooth chamber depth.

[0068] As shown in Figures 17, 26, and 48, the circular saw blade 1 of the first embodiment (see Figure 4) only showed a scale pattern on the cut surface under one condition: 2400 rpm. Under the other conditions, the cut surface was judged to be good (good). Even at 2400 rpm, where the scale pattern appeared, the cut surface was relatively good, so it was judged to be fair (relatively good). The surface roughness Rz was 1.5 μm or less at almost all rotation speeds, with little variation. The surface roughness Rz was smaller than that of the circular saw blade 30 of the third embodiment (see Figure 6), which will be described later.

[0069] As shown in Figures 18, 27, and 48, the circular saw blade 30 of the third embodiment (see Figure 6) had good cut surfaces under seven conditions, but under seven conditions, scale patterns appeared on the cut surfaces and were rated as × (NG). The surface roughness Rz under the seven conditions rated as ◯ was 1.5 μm or less. The surface roughness Rz under the seven conditions rated as × was generally greater than 1.5 μm, but the difference from the ○ rating was small, and there was little variation except for the high rotation speed condition of 4560 rpm. The surface roughness Rz was smaller than that of the circular saw blade 110 of the first comparative example (see Figure 14), which will be described later.

[0070] As shown in Figures 19, 28, and 48, the circular saw blade 40 of the fourth embodiment (see Figure 7) only showed a scale pattern on the cut surface under one condition: 4020 rpm. Under the other conditions, the cut surface was evaluated as good (◯). Even under the condition of 4020 rpm, where a scale pattern was observed, the cut surface was relatively good and was evaluated as fair. The surface roughness Rz was 1.5 μm or less at all rotation speeds, with little variation.

[0071] As shown in Figures 20, 29, and 48, the circular saw blade 50 of the fifth embodiment (see Figure 8) had a good cut surface under eight conditions, a △ rating under one condition in which a scale pattern was visible on the cut surface, and an × rating under five conditions in which a scale pattern was observed on the cut surface. All conditions above 3840 rpm were rated ×. The surface roughness Rz under the nine conditions rated as ◯ and △ was generally around 1.5 μm, with little variation. The surface roughness Rz under the five conditions rated as × was generally greater than 1.5 μm, and under the 4200 rpm condition, the surface roughness Rz was more than twice 1.5 μm. The cut surface under the 4200 rpm condition had a noticeable scale pattern that was easily visible.

[0072] As shown in Figures 21, 30, and 48, the circular saw blade 60 of the sixth embodiment (see Figure 9) had a good cut surface under six conditions, a △ rating under one condition in which a scale pattern was visible on the cut surface, and an × rating under seven conditions in which a scale pattern appeared on the cut surface. The ◯ and × ratings appeared irregularly as the rotation speed increased. The surface roughness Rz under the seven conditions ◯ and △ was smaller than 1.5 μm and had little variation. The surface roughness Rz under the seven conditions ◯ was generally 1.5 μm or slightly larger than 1.5 μm and had relatively little variation.

[0073] As shown in Figure 22, the circular saw blade 100 of the tenth embodiment (see Figure 13) had a good cut surface under seven conditions, a △ rating under two conditions where a scale pattern was visible on the cut surface, and an × rating under five conditions where a scale pattern appeared on the cut surface. While × and △ ratings were observed at rotation speeds of 3,480 rpm or less, all high rotation speeds of 3,660 rpm or more were ◯ ratings. The only difference from the circular saw blade 1 (see Figure 4) was the position of the shallow tooth chamber 12 where the slit 8 was provided, but there was a visible difference in the condition of the cut surface of the workpiece compared to Figure 17.

[0074] As shown in Figures 23, 31, and 48, the circular saw blade 110 of the first comparative example (see Figure 14) had a good cut surface in six conditions, but a scale pattern appeared on the cut surface in eight conditions, resulting in an X rating. The O and X ratings appeared irregularly as the rotation speed increased. The surface roughness Rz in the six conditions rated as O was smaller than 1.5 μm and had little variation. The surface roughness Rz in the eight conditions rated as X was generally 1.5 μm or larger than 1.5 μm and had relatively large variations.

[0075] As shown in Figure 24, the circular saw blade 120 of the second comparative example (see Figure 15) had good cut surfaces under eight conditions, was rated as △ in one condition despite a scale pattern being visible on the cut surface, and was rated as × in five conditions due to a scale pattern appearing on the cut surface. In particular, a noticeable scale pattern appeared on the cut surface of the workpiece at a relatively low rotation speed of 2760 rpm or less.

[0076] As shown in Figures 25, 32, and 48, the circular saw blade 130 of the third comparative example (see Figure 16) had good cut surfaces in five conditions, but had scale patterns on the cut surfaces in nine conditions, resulting in an X rating. The O and X ratings appeared irregularly as the rotation speed increased. The surface roughness Rz in the five O conditions was smaller than 1.5 μm and had little variation. The surface roughness Rz in the nine X conditions was generally 1.5 μm or larger than 1.5 μm and had a large variation. The scale patterns that appeared on the cut surfaces of the workpiece were so noticeable that they were easily visible.

[0077] As shown in Figures 38, 43, and 48, the circular saw blade 140 of the 11th embodiment (see Figure 34) had a good cut surface in eight conditions, a △ rating in two conditions where a scale pattern was visible on the cut surface, and an X rating in four conditions where a scale pattern appeared on the cut surface. The O rating and the X rating including the △ rating appeared irregularly as the rotation speed increased. The surface roughness Rz in the eight O rating conditions was generally around 1.5 μm, with little variation. The surface roughness Rz in the six X and △ rating conditions was generally 1.5 μm or slightly greater than 1.5 μm, with relatively little variation.

[0078] As shown in Figures 39, 44, and 48, the circular saw blade 150 of the 12th embodiment (see Figure 35) produced scale patterns on the cut surface only under one condition: 4380 rpm. The other conditions were evaluated as good, with the cut surface being rated as "O." Even under the 4380 rpm condition, where scale patterns were produced, the cut surface was relatively good and was rated as "△." The surface roughness Rz was generally 1.5 μm or less, or slightly less than 1.5 μm, with little variation.

[0079] As shown in Figures 40, 45, and 48, the circular saw blade 160 of the 13th embodiment (see Figure 36) had a good cut surface in five conditions, a △ rating in two conditions where a scale pattern was visible on the cut surface, and an × rating in seven conditions where a scale pattern appeared on the cut surface. The ◯ rating and the × rating including the △ rating appeared irregularly as the rotation speed increased. The surface roughness Rz of the five ◯ rating conditions was smaller than 1.5 μm and had little variation. The surface roughness Rz of the two △ rating conditions was approximately 1.5 μm and had little variation. The surface roughness Rz of the seven × rating conditions was approximately greater than 1.5 μm and had relatively little variation.

[0080] As shown in Figures 41, 46, and 48, the circular saw blade 170 of the fourth comparative example (see Figure 37) had a good cut surface under six conditions, but under eight conditions, a scale pattern appeared on the cut surface and was rated as x. The o and x ratings appeared irregularly as the rotation speed increased. The surface roughness Rz under the six conditions rated as o was smaller than 1.5 μm and had little variation. The surface roughness Rz under the eight conditions rated as x was generally 1.5 μm or larger than 1.5 μm and had a large variation. The scale pattern that appeared on the cut surface of the workpiece was so noticeable that it was easily visible.

[0081] As shown in Figures 42, 47, and 48, the circular saw blade of the fifth comparative example had a good cut surface under five conditions, but under nine conditions, a scale pattern appeared on the cut surface and was rated as x. The o and x ratings appeared irregularly as the rotation speed increased. The surface roughness Rz of the five conditions rated as o was generally 1.5 μm or less, with little variation. The surface roughness Rz of the nine conditions rated as x was generally 1.5 μm or more, with much variation. The scale pattern that appeared on the cut surface of the workpiece was noticeable and easily visible. The surface roughness Rz was greater than that of the circular saw blade 170 of the fourth comparative example (see Figure 37).

[0082] Based on the above test results, in this disclosure, the tooth chamber depth of deep tooth chambers is set to 1.13 to 1.60 times the average tooth chamber depth. The tooth chamber depth of shallow tooth chambers is set to 0.60 to 0.95 times the average tooth chamber depth. The deep region is set to include only 2 to 3 consecutive deep tooth chambers. The shallow region is set to include only 2 to 7 consecutive shallow tooth chambers.

[0083] As shown in FIG. 33 , a simulation was performed on the displacement of one blade body 3 when a load was applied to the base metal 2 in the axial direction (see FIG. 4 ). The simulation was performed on a blade body 3 sandwiched between two deep tooth chambers 11 and a blade body 3 sandwiched between two shallow tooth chambers 12. The ratio of the tooth chamber depth 11a of the deep tooth chamber 11 to the tooth chamber depth 12a of the shallow tooth chamber 12 and the ratio of the displacement of each blade body 3 were plotted in a graph. The ratio of the displacement increased as the tooth chamber depth ratio increased. Furthermore, the increase in the ratio of the displacement also increased as the tooth chamber depth ratio increased. For example, when the tooth chamber depth ratio increased from 1.5 to 2.0, the ratio of the displacement increased approximately twofold. For example, when the tooth chamber depth ratio increased from 2.0 to 2.5, the ratio of the displacement increased approximately twofold. Therefore, to prevent the ratio of the displacement from becoming too large, the tooth chamber depth ratio in this disclosure is set to 1.3 to 2.0.

[0084] Various modifications can be made to the circular saw blades of the embodiments described above. The number of tooth chambers is not limited to the examples and may be modified as appropriate. The number of deep tooth chambers arranged consecutively in the deep region may be either two or three. The number of shallow tooth chambers arranged consecutively in the shallow region may be modified as appropriate within the range of two to seven. A configuration in which tooth chamber rows including deep and shallow regions are periodically repeated has been exemplified. Alternatively, for example, a configuration in which tooth chamber rows are not repeated over one revolution of the base metal may be used. For example, a configuration in which multiple types of tooth chamber rows are arranged non-periodically may be used.

[0085] The deep region may have deep tooth chambers with two or more different tooth chamber depths. The shallow region may have shallow tooth chambers with two or more different tooth chamber depths. The base metal 2 may have multiple types of slits at the bottom of the tooth chambers, such as slits 8 and 72. As described above, slits may be provided in the shallow tooth chambers 12, or slits may be provided in the deep tooth chambers 11.

[0086] The shape and size of the slits are not limited to those exemplified and may be modified as appropriate. For example, the slits may only have a portion that extends linearly in the radial direction. For example, the slits may not have a portion that extends linearly in the radial direction and are only recessed in an arc shape. For example, the tip depth of the slits may be modified as appropriate within a range of 1.3 to 2.0 times the average tooth chamber depth of the slits, or greater than 1.3 times and up to 8.0 times.

[0087] The shape of the tooth chamber is not limited to the illustrated example, and may be changed as appropriate as long as the conditions for deep and shallow tooth chambers are met. For example, the width of the slit 92 of the circular saw blade 90 may be further widened to form a deep tooth chamber that is bent in an approximately L-shape in cooperation with the tooth chamber 91. The blade shape is not particularly limited.

Claims

1. A circular saw blade comprising: a disk-shaped base metal; a plurality of tooth chambers recessed into the outer periphery of the base metal; and a plurality of tips joined to the outer periphery of the base metal, the plurality of tooth chambers including deep tooth chambers having a tooth chamber depth that is 1.13 to 1.60 times the average tooth chamber depth and shallow tooth chambers having a tooth chamber depth that is 0.60 to 0.95 times the average tooth chamber depth, the circular saw blade having a deep region including only 2 to 3 consecutive deep tooth chambers and a shallow region including only 2 to 7 consecutive shallow tooth chambers.

2. A circular saw blade according to claim 1, wherein a tooth chamber with a slit connecting the tooth chamber is adjacent to the deep region.

3. A circular saw blade according to claim 1 or 2, wherein the deep regions and the shallow regions are arranged alternately.

4. A circular saw blade as claimed in claim 1, wherein, instead of at least one of said deep tooth chambers, a tooth chamber with a slit is provided which is connected to said tooth chamber via a slit, and the difference between the radius of the end of said slit on the axial side and the radius of the outermost periphery of the cutting edge is 1.3 to 2.0 times the average tooth chamber depth.

5. A circular saw blade comprising a disk-shaped base metal, a plurality of tooth chambers recessed into the outer periphery of the base metal, and a plurality of tips joined to the outer periphery of the base metal, the plurality of tooth chambers including slitted tooth chambers connected by slits extending radially inward from the tooth chambers, and unslitted tooth chambers to which the slits are not connected, and having a deep region including only 2 to 3 consecutive slitted tooth chambers, and a shallow region including only 2 to 7 consecutive unslit tooth chambers.

6. A circular saw blade as claimed in claim 5, wherein the difference between the radius of the axial end of the slit and the radius of the outermost periphery of the cutting edge is 1.3 to 2.0 times the average depth of the tooth chamber.

7. A circular saw blade according to claim 5 or 6, wherein the deep regions and the shallow regions are arranged alternately.

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