Circular saw blade

Abstract

A circular saw blade (1) for cutting metal has a disc-shaped base body (2), a tooth chamber (5) which opens toward the radially outer side at the outer periphery of the base body (2), and a bit seat (6) which is recessed at the rear end in the direction of rotation of the tooth chamber (5). The circular saw blade (1) has a bit (10) which is mounted in the bit seat (6) and projects radially outward beyond the base body (2). The bit (10) has a blade thickness which is thicker than the thickness (2c) of the base body (2). The bit (10) has a thin-walled portion (15) on the radially inner side which has a thickness which is less than the thickness (2c) of the base body (2). In the thickness direction, the thin-walled portion (15) is located within the thickness of the bit seat (6).

Description

Technical Field

[0001] One aspect of this disclosure relates to a disc-shaped circular saw blade. The circular saw blade is used, for example, for cutting various metal workpieces, and has multiple cutting heads mounted on its outer periphery. Background Technology

[0002] Conventional circular saw cutting machines are known for high-speed cutting of various metal parts. Such machines typically utilize a disc-shaped circular saw blade with a cutting thickness of 2 mm. The circular saw blade for metal cutting cuts the workpiece by forming grooves in the workpiece, which may be made of steel or non-ferrous materials such as aluminum. The circular saw blade has a disc-shaped base and multiple cutting heads mounted at predetermined intervals on the outer periphery of the base. These cutting heads are, for example, hardened carbide or cermet.

[0003] As described in Japanese Patent No. 3895906, conventional circular saw blades for metal cutting have cutting heads. The cutting head is thicker than the base material and has a planar side shape. The joint portion of the cutting head, which engages with the base material, extends beyond the base material in the thickness direction. When cutting the workpiece, chips are generated at the cutting edge. These chips are contained in a toothed chamber located between circumferentially adjacent cutting heads. When the circular saw blade rotates, the chips collide with the joint portion of the cutting head extending in the thickness direction. There is a possibility that damage may occur in the cutting head starting from the point of chip collision. Damage is particularly prone to occur in the area near the joint portion. Therefore, a cutting head capable of suppressing damage to the joint portion is desired.

[0004] In conventional circular saw blades for metal cutting, a chip-breaking section is formed on the rake face of the blade tip. Viewed from the thickness direction of the blade tip, the chip-breaking section is arc-shaped. The chips generated at the cutting edge are fed along the arc-shaped surface of the chip-breaking section, thus bending into a spring-like shape. Utilizing the elasticity of the spring-shaped chips, they can be discharged from the tooth chamber of the circular saw blade.

[0005] Circular saw blades for metal cutting are used for cutting, for example, hard pipes, soft hoses, or solid materials. When cutting solid materials, the amount of chips produced per revolution of the saw head is greater than when cutting hard pipes or soft hoses. There are instances where the tooth chamber volume of the circular saw blade is insufficient relative to the size of the workpiece, or where the generated chips are excessively compressed within the chip-breaking section. In such cases, chips cannot be properly discharged from the tooth chamber, resulting in cutting blockage. Therefore, the applicability of a circular saw blade is limited by the cutting conditions, such as the size of the workpiece. Therefore, there is a need for a circular saw blade for metalworking that can cut a wide range of workpieces. Summary of the Invention

[0006] The problem the invention aims to solve

[0007] As mentioned above, in circular saw blades used for metal cutting, there are instances where the blade tip is damaged or the cutting surface becomes clogged due to chip impact. As a result, the cutting performance of the circular saw blade deteriorates. Therefore, there is a need for a circular saw blade for metal cutting that can suppress the reduction in cutting performance caused by the influence of chips.

[0008] means for solving problems

[0009] According to a feature of this disclosure, a circular saw blade for metal cutting comprises: a disc-shaped base; a toothed chamber opening radially outward on the outer periphery of the base; and a cutter head seat recessed at the rear end in the rotational direction of the toothed chamber. The circular saw blade has a cutter head mounted on the cutter head seat, protruding radially outward from the base. The cutter head has a cutting edge with a rake face and a flank face intersecting. The cutting edge thickness of the cutter head is greater than the thickness of the base. The cutter head has a thin-walled portion on its radially inner side, with a thickness less than the thickness of the base. In the thickness direction, the thin-walled portion is located within the thickness of the cutter head seat.

[0010] Therefore, the side of the thin-walled portion on the radially inner side of the cutter head does not protrude beyond the base body in the thickness direction. This suppresses chip impact at the radially inner joint of the cutter head, thus preventing cutter head defects. Furthermore, it suppresses cutting blockage at the radially inner joint of the cutter head. Therefore, it suppresses cutter head defects caused by chip impact and reduced cutting performance due to cutting blockage.

[0011] According to other features of this disclosure, in the cutting edge, the rake angle formed by the rake face and the radial line of the base is negative. Therefore, it can be ensured that the rotational length of the thin-walled portion located radially inner to the cutting head is longer than the rotational length of the radially outer region of the cutting head. Therefore, it can be ensured that the area of ​​the joint between the cutting head 10 and the cutting head seat is large. Thus, it is possible to suppress the cutting head from peeling off from the cutting head seat and to suppress the decrease in cutting performance.

[0012] According to other features of this disclosure, the cutting head has an inner region that is radially inward from the front end of the cutting head seat in the rotation direction. The thin-walled portion occupies the entire area of ​​the inner region. Therefore, it is possible to suppress the protrusion in the thickness direction in the entire area of ​​the joint of the thin-walled portion of the cutting head where chips are prone to collision. Therefore, it is possible to more reliably suppress cutting head defects and cutting blockage near the front end of the cutting head joint in the rotation direction.

[0013] According to other features of this disclosure, the thin-walled portion has a first surface extending radially inward from the front surface of the cutting head toward the rearward direction of rotation. The thin-walled portion has a second surface extending rearward from the first surface in the rotational direction. The thin-walled portion has a third surface extending radially outward from the rearward end of the second surface in the rotational direction. The cutting head has a rake face on the front side in the rotational direction. A chip-breaking portion is provided in an arc-shaped recess on the radially inward side of the rake face toward the rearward direction of rotation.

[0014] Therefore, the thin-walled portion can be formed into a shape that convexes radially inward from the first to third surfaces. This allows the cutter head to be securely mounted on the cutter head holder. Furthermore, it suppresses displacement of the cutter head relative to the cutter head holder in the rotational direction. Ensuring that the radial length of the radially outer region is longer than the thin-walled portion increases the radius of curvature of the chip-breaking section. This suppresses cutting blockage within the chip-breaking section. Thus, for example, it is possible to cut solid materials with a diameter larger than that applicable to conventional circular saw blades. Attached Figure Description

[0015] Figure 1 This is a side view of a circular saw blade.

[0016] Figure 2 yes Figure 1 Enlarged side view of section II.

[0017] Figure 3 This is the front view from the front face of the cutter head.

[0018] Figure 4 This is a top view taken from the back face of the cutter head. Detailed Implementation

[0019] based on Figures 1-4 This description illustrates preferred embodiments of the present disclosure. While the same reference numerals are not repeated in the description, they denote the same elements having the same function. In this embodiment, a circular saw blade 1 for metalworking is shown as an example. For example... Figure 1 As shown, the circular saw blade 1 has a disc-shaped base 2 and multiple cutting heads 10 mounted on the outer periphery of the base 2. By rotating the base 2, each cutting head 10 forms a groove in the workpiece, ultimately cutting off the workpiece. The workpiece can be, for example, ferrous materials such as carbon steel, general structural rolled steel, chromium-molybdenum steel, stainless steel, and cast iron, or non-ferrous metals such as aluminum and aluminum alloys, copper and copper alloys. The workpiece can also be, for example, a tubular flexible or rigid pipe, or a rod-shaped solid material. The workpiece is cut to a predetermined length by the circular saw blade 1. The workpiece is cut, for example, at room temperature.

[0020] like Figure 1 As shown, the base 2 has a disc-shaped main body 2a and a generally circular mounting hole 3 extending through the thickness direction of the base 2 at the center of the main body 2a. The rotating shaft of the circular saw is inserted into the mounting hole 3. The circular saw blade 1 rotates around the axis 2b of the base in the circumferential direction of the main body 2a. A plurality of cutting heads 10 arranged on the outer periphery of the base 2 sequentially reach the workpiece to be cut from the front in the direction of rotation. Preferably, the outer diameter of the circular saw blade 1 is 200 mm to 500 mm, for example, 285 mm. The base 2 is, for example, made of steel. Preferably, the thickness 2c of the base 2 (refer to...) Figure 3 The thickness is 0.6 to 1.8 mm, for example, 1.7 mm.

[0021] like Figure 1 , 2 As shown, the base 2 has a plurality of protrusions 4 extending radially outward from the outer periphery of the main body 2a. The plurality of protrusions 4 are formed at equal intervals 4a in the circumferential direction of the outer periphery of the main body 2a. Tooth chambers 5 are formed between adjacent protrusions 4. A cutter head seat 6 is formed on each protrusion 4, opening radially outward in the direction of rotation. Cutter heads 10 are mounted on each cutter head seat 6. Preferably, the circular saw blade 1 has 40 to 200 cutter heads 10, for example, 120 cutter heads 10.

[0022] like Figures 2-4 As shown, the cutting head 10 has a rectangular box-shaped cutting head body 10a and a rectangular box-shaped thin-walled portion 15 disposed radially inner to the cutting head body 10a. The cutting head body 10a has a height 10f of, for example, 2.0 mm in the radial direction. The cutting head body 10a has a rake face 12 facing forward in the direction of rotation and a flank face 13 facing outward in the radial direction. A cutting edge 11 is formed at the intersection of the rake face 12 and the flank face 13. The cutting edge 11 extends in the thickness direction with a cutting edge thickness 10e that is slightly larger than the thickness 2c of the base body 2. Preferably, the cutting edge thickness 10e is 0.8 mm to 2.0 mm, for example, 2.0 mm.

[0023] Figure 2 The cutter head 10 shown is, for example, a hardened cutter head formed of a superhard alloy or a cermet. A hardened alloy can be obtained, for example, by mixing tungsten carbide with cobalt as a binder and then sintering. A cermet can be obtained by mixing TiN, TiC, TiCN, etc., with cobalt as a binder and then sintering. A coating to improve wear resistance can be applied to the surface of the cutter head 10.

[0024] like Figures 2-4 As shown, a groove 13a extending in the circumferential direction is formed on the flank face 13. The groove 13a extends from the cutting edge 11 at the front end of the flank face 13 in the direction of rotation to the rear end of the flank face 13 in the direction of rotation. Viewed from the front in the direction of rotation of the circular saw blade 1, the groove 13a is approximately U-shaped. By setting the groove 13a, the cutting edge 11 is divided into the left and right sides of the groove 13a. Therefore, the chips cut from the workpiece are divided into left and right sides by the cutting edge 11 divided by the groove 13a. The groove 13a is set at a position offset to the left or right by a predetermined distance relative to the center of the thickness direction of the saw head 10. The saw head 10 has a first saw head 7 with the groove 13a offset to the left relative to the center of the thickness direction and a second saw head 8 with the groove 13a offset to the right relative to the center of the thickness direction. The first saw head 7 and the second saw head 8 are alternately mounted in the circumferential direction of the base 2.

[0025] like Figure 2As shown, the clearance angle 10d between the circumferential tangent of the substrate 2 and the rake face 13 is preferably 5° to 15°, for example, 10°. The rake angle 10c of the rake face 12, which is radially inclined relative to the substrate 2, is preferably -30° to -5°, for example, -20°.

[0026] like Figure 2 , 3 As shown, a chip-breaking portion 12a is provided in the radially inner region of the rake face 12, recessed towards the rear in the direction of rotation. The chip-breaking portion 12a is configured to extend across the thickness of the cutter body 10a as a whole. Viewed in the thickness direction, the chip-breaking portion 12a is arc-shaped. The chips cut by the cutting edge 11 are fed to the rake face 12 side and curled into a spring shape by the chip-breaking portion 12a. The chips curled by the chip-breaking portion 12a are discharged from the groove or tooth chamber 5 formed in the workpiece by the elastic force.

[0027] like Figure 2 As shown, the radius of curvature of the chip breaker 12a is at least 50% of the height 10f of the cutter body 10a, for example, 1.2 mm. The cutter body 10a has a front surface 20 extending radially inward from the radially inner side of the chip breaker 12a toward the radially inner side of the base 2. The angle 12b between the radially inner side of the chip breaker 12a and the front surface 20 is, for example, 35°. The angle 12c between the radially outer side of the chip breaker 12a and the extended surface of the rake face 12 is, for example, 30°.

[0028] like Figure 3 As shown, the cutter body 10a has side surfaces 14 at both ends of the flank face 13 in the thickness direction. The side surfaces 14 have an angle of 0° to 2° relative to the radial direction of the base body 2, for example, an inwardly inclined angle (side radial angle) of 30′. This slight inclination reduces the contact area between the side surfaces 14 and the workpiece being cut. Therefore, the cutting resistance of the side surfaces 14 is reduced. Furthermore, the side surfaces 14 are inclined in a way that does not excessively protrude from the cut surface of the workpiece, thus enabling smooth machining of the cut surface.

[0029] like Figures 2-4 As shown, an upper chamfer 14a is formed between the flank face 13 and the side face 14. Viewed from the front in the rotation direction, the upper chamfer 14a is inclined relative to the flank face 13, for example, having a chamfer angle 14c of 45°. The upper chamfer 14a is formed as a plane with a thickness direction width that is approximately the same from the front to the rear in the rotation direction of the flank face 13. The thickness direction width of the upper chamfer 14a is, for example, 0.05 mm to 0.1 mm.

[0030] like Figure 2As shown, the thin-walled portion 15 is located at least radially inward from the radially inner region of the front surface 20 of the cutter head 10. Specifically, the cutter head 10 has an inner region that is inside the arc passing through the radially inner end of the front surface 20 and through the center of the base 2. The inner region of the cutter head 10 is occupied by the thin-walled portion 15. The thin-walled portion 15 is also located radially outward from the inner region. For example, the thin-walled portion 15 is located along a tangent line L2 that is tangent to the arc passing through the radially inner end of the front surface 20 and through the center of the base 2.

[0031] like Figure 2 , 3 As shown, the thin-walled portion 15 has a thickness 15a of 10e or less. The thickness 15a is less than or equal to the thickness 2c of the base 2, for example, 1.7 mm, the same as the thickness 2c. The side surface 21 of the thin-walled portion 15 mounted on the cutter head holder 6 is approximately flush with the side surface of the base 2, and at least does not extend outwards to the left or right beyond the side surface of the base 2. Therefore, in the thickness direction, the thin-walled portion 15 is mounted on the cutter head holder 6 within the thickness of the cutter head holder 6.

[0032] like Figure 2 As shown, the thin-walled portion 15 is generally trapezoidal when viewed in the thickness direction. The thin-walled portion 15 has a first surface 16, a second surface 17, and a third surface 18, all planar and facing radially inward. The first surface 16 extends radially inward from the radially inward region of the front surface 20 toward the rearward direction of rotation. The first surface 16 has an inclination angle 16a relative to the radial line L1 extending radially in the base 2. Preferably, the inclination angle 16a is 30° to 60°, for example, 45°. The rotational length of the first surface 16 is, for example, 20% to 40% of the rotational length of the cutting head 10, for example, 0.5 mm.

[0033] like Figure 2 As shown, the second surface 17 extends approximately orthogonally to the radial line L1 and approximately parallel to the circumferential line L2, starting from the rear end of the first surface 16 in the direction of rotation. The second surface 17 is positioned at the innermost radial side of the thin-walled portion 15. The thin-walled portion 15 has, for example, a radial height 15b that is 10 to 30% of the height 10f of the cutter body 10a. The height 15b is, for example, 0.5 mm, which corresponds to the radial distance from the radially inner region of the front surface 20 to the second surface 17.

[0034] like Figure 2As shown, the third face 18 extends radially outward from the rear end of the second face 17 in the direction of rotation. The third face 18 has an inclination angle 18a relative to the radial line L1. Preferably, the inclination angle 18a is 30° to 60°, for example, 45°. The length of the third face 18 in the direction of rotation is, for example, 10% to 30% of the length of the cutting head 10 in the direction of rotation, for example, 0.3 mm. The rear end 18b of the third face 18 in the direction of rotation is located radially inward than the radially inward region of the front surface 20. The cutting head 10 has a planar rear end face 19 extending radially outward from the radially outer side of the third face 18 to the rear cutting face 13. The rear end face 19 extends substantially parallel to the radial line L1.

[0035] like Figure 2 As shown, the cutter head holder 6 has a planar first surface 6b, a second surface 6c, a third surface 6d, and a rear end surface 6e, all modeled after the shape of the cutter head 10. The cutter head 10 is soldered to the first surface 6b, the second surface 6c, the third surface 6d, and the rear end surface 6e of the cutter head holder 6 using silver solder or the like. The radially inner region of the front surface 20 of the cutter head 10 is positioned approximately at the same location as the front end 6a in the rotation direction of the cutter head holder 6.

[0036] like Figure 3 As shown, the thin-walled portion 15 has radially extending side surfaces 21 on both sides in the thickness direction. A lower chamfer 14b is formed between the radially outer region of the side surface 21 of the thin-walled portion 15 and the radially inner region of the side surface 14 of the blade body 10a. The lower chamfer 14b is inclined relative to the rotation axis direction of the circular saw blade 1, for example, having a chamfer angle 14d of 45°. The lower chamfer 14b is formed as a plane with a width approximately the same in the rotation direction. The width of the lower chamfer 14b in the thickness direction is, for example, 0.10 to 0.15 mm.

[0037] As mentioned above, such as Figure 2 , 3 As shown, the circular saw blade 1 for metal cutting has a disc-shaped base 2, a toothed chamber 5 opening radially outward on the outer periphery of the base 2, and a cutter head seat 6 recessed at the rear end of the toothed chamber 5 in the direction of rotation. The circular saw blade 1 has a cutter head 10 mounted on the cutter head seat 6 and protruding radially outward from the base 2. The cutter head 10 has a cutting edge 11 where a front face 12 and a rear face 13 intersect. The cutting edge thickness 10e of the cutter head 10 is thicker than the thickness 2c of the base 2. A thin-walled portion 15 with a thickness less than or equal to the thickness 2c of the base 2 is formed on the radially inner side of the cutter head 10. The thin-walled portion 15 is located within the thickness of the cutter head seat 6 in the thickness direction.

[0038] Therefore, the side surface 14 of the thin-walled portion 15 on the radially inner side of the cutter head 10 is formed such that it does not protrude beyond the base body 2 in the thickness direction. This suppresses chip impact at the radially inner joint of the cutter head 10, thus preventing damage to the cutter head 10. Furthermore, it suppresses cutting blockage at the radially inner joint of the cutter head 10. Therefore, it suppresses chip damage to the cutter head 10 and the reduction in cutting performance due to cutting blockage.

[0039] like Figure 2 As shown, in the cutting edge 11, the rake angle 10c formed by the rake face 12 and the radial line L1 of the base 2 is negative. For example, the rake face 12 extends radially inward and in the rotational direction from the cutting edge 11. Therefore, it can be ensured that the rotational length of the thin-walled portion 15 provided on the radially inner side of the cutter head 10 is longer than the rotational length of the radially outer region of the cutter head 10. Therefore, it can be ensured that the area of ​​the joint between the cutter head 10 and the cutter head seat 6 on the radially inner side is large. As a result, it is possible to suppress the peeling of the cutter head 10 from the cutter head seat 6 and to suppress the decrease in cutting performance.

[0040] like Figure 2 , 3 As shown, the cutting head 10 has an inner region that is radially inward from the rotating front end 6a of the cutting head seat 6. The thin-walled portion 15 occupies the entire inner region. Therefore, it is possible to suppress the protrusion in the thickness direction in the entire region of the joint of the thin-walled portion 15 of the cutting head 10, where chips are prone to collision. Therefore, it is possible to more reliably suppress defects and cutting blockages in the cutting head 10 near the rotating front end of the joint.

[0041] like Figure 2 As shown, the thin-walled portion 15 has a first surface 16 extending radially inward from the radially inner side of the front surface 20 toward the rearward direction in the rotational direction. The thin-walled portion 15 has a second surface 17 extending rearward from the first surface 16 in the rotational direction. The thin-walled portion 15 has a third surface 18 extending radially outward from the rearward end of the second surface 17 in the rotational direction. A rake face 12 is provided on the front side of the cutting head 10 in the rotational direction. A chip-breaking portion 12a is provided in an arc shape recessed on the radially inner side of the rake face 12 toward the rearward direction in the rotational direction.

[0042] Therefore, as Figure 2As shown, the thin-walled portion 15 can be formed into a shape that convexes radially inward by the first surface 16, the second surface 17, and the third surface 18. Therefore, the cutting head 10 can be securely mounted on the cutting head seat 6. In addition, displacement of the cutting head 10 relative to the cutting head seat 6 in the rotational direction is suppressed. By ensuring that the radial length (height 10f) of the radially outer region is longer than that of the thin-walled portion 15, the radius of curvature of the chip-breaking portion 12a is increased. As a result, the chips do not form a distorted shape within the chip-breaking portion 12a, and cutting blockage within the chip-breaking portion 12a can be suppressed. Therefore, the number of teeth of the circular saw blade 1 can be increased, and the maximum number of working teeth (the maximum number of teeth that enter the groove formed in the workpiece during cutting) can be increased compared to the past. The maximum number of working teeth of conventional circular saw blades is approximately 3.5 teeth, while the maximum number of working teeth of the circular saw blade 1 of this disclosure is increased to 5 teeth. As a result, for example, it is possible to cut solid materials with a diameter larger than that of solid materials, which is the applicable range of conventional circular saw blades 1.

[0043] The circular saw blade 1 of this embodiment described above can be modified in various ways. An example is shown of a circular saw blade 1 with protrusions 4 arranged at equal intervals 4a in the circumferential direction of the base 2. It is also possible to replace the above structure with unequal intervals 4a. An example is shown of a structure using two types of cutting heads 10 (first cutting head 7 and second cutting head 8) with different left and right positions of the groove 13a to divide and cut the workpiece in the left and right direction. The circular saw blade 1 can have three or more types of cutting heads 10 with different left and right positions of the groove 13a to replace the above structure. For example, a V-shaped groove can be provided on the back face 13 instead of a U-shaped groove 13a.

[0044] An example is shown where the thickness 2c of the base 2 and the thickness 15a of the thin-walled portion 15 are the same, and the cutting head 10 is mounted on the cutting head holder 6 such that the side surface of the base 2 and the side surface 21 of the thin-walled portion 15 are on the same plane. The thickness 15a of the thin-walled portion 15 can be thinner than the thickness 2c of the base 2 to replace the above structure. As long as the side surface 21 of the thin-walled portion 15 does not extend beyond the thickness direction of the base 2, the center of the cutting head 10 in the thickness direction can be displaced to the left or right relative to the center of the base 2 in the thickness direction. The ridge line where the front surface 20 of the cutting head 10 intersects the first surface 16 can be positioned radially outward from the front end 6a of the cutting head holder 6 in the rotation direction.

Claims

1. A circular saw blade for cutting metal, wherein, have: A disc-shaped substrate. The toothed chamber opens radially outward on the outer periphery of the base. The cutter head holder is recessed at its rear end in the rotational direction of the gear chamber, and The cutting head is mounted on the cutting head seat and protrudes radially outward from the base body; The cutter head has a cutting edge with a rake face and a flank face intersecting, and the thickness of the cutting edge is greater than the thickness of the base body. The cutting head has a thin-walled portion on its radially inner side with a thickness less than that of the base body, and in the thickness direction, the thin-walled portion is located within the thickness of the cutting head seat.

2. The circular saw blade of claim 1, wherein, The rake angle of the rake face is negative.

3. The circular saw blade of claim 1 or 2, wherein, The cutter head has an inner region that is radially inward from the front end of the cutter head seat in the direction of rotation, and the thin-walled portion occupies the entire area of ​​the inner region.

4. The circular saw blade according to claim 1 or 2, wherein, The thin-walled portion has: The first surface extends radially inward from the front surface of the cutter head toward the direction of rotation; The second surface extends rearward from the first surface in the direction of rotation; and The third surface extends radially outward from the rear end of the second surface in the direction of rotation.

5. The circular saw blade of claim 1 or 2, wherein, The cutting head has a front cutting surface on the front side in the direction of rotation, and a chip-breaking portion is provided in an arc shape on the radially inner side of the front cutting surface facing the rear in the direction of rotation.

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