Circular saw

Abstract

To enhance the cutting efficiency of a circular saw that uses a battery as a power source.SOLUTION: A circular saw includes: a rotatable circular saw blade having a substantially circular shape; an electric motor configured to provide rotational driving power to the circular saw blade; and a battery attachment portion configured to be detachably attached with a battery for supply electric power to the electric motor. A diameter of the circular saw blades is 300 mm to 460 mm inclusive.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a marnoko.

Background Art

[0002] A cutting machine called a portable marnoko (hereinafter simply referred to as a marnoko) includes a base and a main body. The main body includes an electric motor and a circular saw blade that is rotationally driven by the electric motor. The main body is disposed on one side with respect to the base, but a part of the circular saw blade protrudes to the other side beyond the base. When using such a marnoko, the user brings the lower surface of the base into contact with the material to be cut with the circular saw blade rotating, and moves the cutting machine forward. As a result, the circular saw blade protruding beyond the base cuts the material to be cut. Patent Document 1 below discloses a portable marnoko that uses a battery as a power source for the electric motor as one type of such a marnoko.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, in a marnoko that uses a battery as a power source as in Patent Document 1, the diameter of the circular saw blade is small (for example, 125 mm in diameter), and the cutting efficiency is poor. This problem is common not only to portable marnokos but also to marnokos that are fixedly installed on a workbench and used. For this reason, it is expected to improve the cutting efficiency of a marnoko that uses a battery as a power source.

[0005] This specification discloses a circular saw. This circular saw may include a rotatable circular saw blade, an electric motor for providing a rotational driving force to the circular saw blade, and a battery mounting portion configured to removably mount a battery for supplying power to the electric motor. The diameter of the circular saw blade may be 300 mm or more and 460 mm or less.

[0006] According to this circular saw, since the diameter of the circular saw blade is 300 mm or more and 460 mm or less, the radius of curvature of the circular saw blade is larger (the curvature is smaller) compared to a battery-powered circular saw having a conventional small-diameter circular saw blade. Therefore, even a workpiece having a large cross-section can be efficiently cut.

[0007] This specification discloses a circular saw. This circular saw may include a rotatable circular saw blade, an electric motor for providing a rotational driving force to the circular saw blade, a rotatable final output shaft to which the rotational driving force of the electric motor is transmitted, the final output shaft to which the circular saw blade is attached, and a battery mounting portion configured to removably mount a battery for supplying power to the electric motor. When the torque of the final output shaft is 5 N / m, the value obtained by multiplying the peripheral speed of the cutting edge of the circular saw blade by the diameter of the circular saw blade may be 6.0 m 2 / s or more.

[0008] According to this circular saw, even a workpiece having a large cross-section can be efficiently cut because the circular saw blade having a sufficient diameter rotates at a sufficient peripheral speed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Mode for Carrying Out the Invention

[0010] Hereinafter, representative and non-limiting specific examples of the present invention will be described in detail with reference to the drawings. This detailed description is merely intended to show those skilled in the art the details for implementing preferred examples of the present invention and is not intended to limit the scope of the present invention. Also, the additional features and inventions disclosed below can be used separately or together with other features and inventions in order to provide further improved devices, their manufacturing methods, and usage methods.

[0011] Also, the combinations of features and steps disclosed in the following detailed description are not essential for practicing the invention in the broadest sense and are described only for the purpose of explaining representative specific examples of the invention in particular. Further, the various features of the above and below representative specific examples, as well as the various features described in the independent and dependent claims, need not be combined as described in the specific examples herein or in the order recited in providing additional and useful embodiments of the invention.

[0012] All features described in this specification and / or the claims are intended to be disclosed separately and independently of each other as limitations to the initial disclosure and the claimed specific matters, apart from the configuration of the features described in the embodiments and / or the claims. Further, all descriptions regarding numerical ranges and groups or populations are made with the intention of disclosing intermediate configurations as limitations to the initial disclosure and the claimed specific matters.

[0013] In one or more embodiments, the miter saw may be configured such that the circular saw blade rotates at a peripheral speed of 70.0 m / s or less under no load. According to this configuration, the difference in the peripheral speed of the circular saw blade between no load and load can be reduced. Therefore, the behavior of the miter saw when starting to cut the workpiece to be cut becomes stable. As a result, the user experience is improved and the cut surface of the workpiece to be cut can be made flatter.

[0014] In one or more embodiments, the miter saw may be configured such that the circular saw blade rotates at a peripheral speed of 50.0 m / s or less under no load. According to this configuration, the difference in the peripheral speed of the circular saw blade between no load and load can be reduced. Therefore, the behavior of the miter saw when starting to cut the workpiece to be cut becomes even more stable.

[0015] In one or more embodiments, the miter saw may be configured such that the circular saw blade rotates at a peripheral speed of 25.0 m / s or more under load. According to this configuration, even a workpiece having a large cross-section can be efficiently cut at a sufficient peripheral speed.

[0016] In one or more embodiments, the miter saw may be configured such that the circular saw blade rotates at a peripheral speed of 28.0 m / s or more under load. According to this configuration, the workpiece can be cut more efficiently.

[0017] In one or more embodiments, the miter saw may be configured to rotate such that the force at the cutting edge of the circular saw blade under load is 20.0 N or more. The "force at the cutting edge" is the force exerted by the cutting edge on the cutting portion of the workpiece. According to this configuration, even a workpiece having a large cross-section can be efficiently cut by applying sufficient force to the workpiece.

[0018] In one or more embodiments, the miter saw may be configured to rotate such that the force at the cutting edge of the circular saw blade under load is 30.0 N or more. According to this configuration, the workpiece can be cut more efficiently.

[0019] In one or more embodiments, the miter saw may be provided with a battery. The rated voltage of the battery may be 18 V or more and 80 V or less. According to this configuration, even a workpiece having a large cross-section can be efficiently cut with sufficient battery output.

[0020] In one or more embodiments, the miter saw may be provided with a battery. The rated voltage of the battery may be 36 V. According to this configuration, the miter saw can achieve a good balance between compactification (weight reduction) and high output.

[0021] In one or more embodiments, the circular saw may include a speed reduction mechanism configured to reduce the rotational driving force of the electric motor and transmit it to the circular saw blade. The reduction ratio of the speed reduction mechanism may be 7 or more. According to this configuration, even for a workpiece having a large cross-section, the workpiece can be efficiently cut with sufficient torque.

[0022] In one or more embodiments, the circular saw may be in the form of a portable circular saw. The portable circular saw may include a first handle having a first gripping portion, and a second handle having a second gripping portion, the second handle being disposed in front of the first handle when the direction in which cutting is advanced by the portable circular saw is defined as the front side and the side opposite to the front side is defined as the rear side. The battery mounting portion may be configured such that when a battery is mounted on the battery mounting portion, the entire battery is positioned between the front edge of the first gripping portion and the front edge of the second gripping portion in the front-rear direction. According to this configuration, since the heavy battery is positioned between the front edge of the first gripping portion and the front edge of the second gripping portion, even though the portable circular saw has a large-diameter circular saw blade (a circular saw blade with a diameter of 300 mm or more), the weight balance is improved when the user holds the portable circular saw by gripping the first gripping portion and the second gripping portion. Therefore, the user can stably hold the portable circular saw with less force.

[0023] In one or more embodiments, the pruning shears may be in the form of portable pruning shears. The portable pruning shears may include a first handle having a first gripping portion, and a second handle having a second gripping portion, the second handle being disposed in front of the first handle when the direction in which cutting is advanced by the portable pruning shears is defined as the front side and the side opposite the front side is defined as the rear side. The center of gravity of the pruning shears with the battery mounted on the battery mounting portion may be located below the lower edge of the first gripping portion and the lower edge of the second gripping portion in the vertical direction in the posture during use of the portable pruning shears. According to this configuration, when the user holds the portable pruning shears by gripping the first gripping portion and the second gripping portion, the portable pruning shears can be stably held with less force.

[0024] In one or more embodiments, the pruning shears may be in the form of portable pruning shears. The portable pruning shears may include a first handle having a first gripping portion, and a second handle having a second gripping portion, the second handle being disposed in front of the first handle when the direction in which cutting is advanced by the portable pruning shears is defined as the front side and the side opposite the front side is defined as the rear side, and a battery. The center of gravity of the battery with the battery mounted on the battery mounting portion may be located below the lower edge of the first gripping portion and the lower edge of the first gripping portion in the vertical direction in the posture during use of the portable pruning shears. Since the center of gravity of the heavy battery is located below the gripping portions of the first gripping portion and the second gripping portion, when the user holds the portable pruning shears by gripping the first gripping portion and the second gripping portion, the portable pruning shears can be stably held with less force.

[0025] In one or more embodiments, the portable saw may be in the form of a portable saw. The portable saw may include a first handle having a first gripping portion, and a second handle having a second gripping portion, the second handle being disposed in front of the first handle when the direction in which cutting is advanced by the portable saw is defined as the front side and the side opposite to the front side is defined as the rear side. Let the distance between a first center point, which is the center point of the region where the user actually grips the first gripping portion of the first gripping portion in the front-rear direction, and a second center point, which is the center point of the second gripping portion, be L1, and the distance between the first center point and a first center of gravity, which is the center of gravity of the saw in a state where a battery is mounted on the battery mounting portion, in the front-rear direction be L2. Then, the value of L2 / L1 may be 0.5 or more and 0.7 or less. According to this configuration, even though the portable saw has a large-diameter circular saw blade (a circular saw blade with a diameter of 300 mm or more), the weight balance when the user holds the portable saw by gripping the first gripping portion and the second gripping portion is improved. Therefore, the user can stably hold the portable saw with less force.

[0026] In one or more embodiments, let the distance between a first center point, which is the center point of the region where the user actually grips the first gripping portion of the first gripping portion in the vertical direction in the posture of the portable saw during use, and a second center point, which is the center point of the second gripping portion, be L3, and the distance between the first center point and a first center of gravity, which is the center of gravity of the saw in a state where a battery is mounted on the battery mounting portion, in the vertical direction be L4. Then, the value of L4 / L3 may be 3.4 or more and 3.8 or less. According to this configuration, the weight balance when the user holds the portable saw by gripping the first gripping portion and the second gripping portion is improved.

[0027] In one or more embodiments, when the distance between a first center point, which is the center point of the region where the user actually grips the first gripping portion in the front-rear direction of the first gripping portion, and a second center point, which is the center point of the second gripping portion, is defined as L1, and the distance between the first center point and a second center of gravity, which is the center of gravity of the battery in a state where the battery is mounted on the battery mounting portion in the front-rear direction, is defined as L5, the value of L5 / L1 may be 0.1 or more and 0.3 or less. According to this configuration, the weight balance when the user holds the portable saw by gripping the first gripping portion and the second gripping portion is improved.

[0028] In one or more embodiments, when the distance between a first center point, which is the center point of the region where the user actually grips the first gripping portion in the vertical direction in the posture of the portable saw during use, and a second center point, which is the center point of the second gripping portion, is defined as L3, and the distance between the first center point and a second center of gravity, which is the center of gravity of the battery in a state where the battery is mounted on the battery mounting portion in the vertical direction, is defined as L6, the value of L6 / L3 may be 2.8 or more and 3.2 or less. According to this configuration, the weight balance when the user holds the portable saw by gripping the first gripping portion and the second gripping portion is improved.

[0029] In one or more embodiments, when the distance between a first center point, which is the center point of the region where the user actually grips the first gripping portion in the axial direction, which is the direction in which the rotation axis of the circular saw blade extends, and a second center point, which is the center point of the second gripping portion, is defined as L7, and the distance between the first center point and a first center of gravity, which is the center of gravity of the saw in a state where the battery is mounted on the battery mounting portion in the axial direction, is defined as L8, the value of L8 / L7 may be 0.4 or more and 0.7 or less. According to this configuration, the weight balance when the user holds the portable saw by gripping the first gripping portion and the second gripping portion is improved.

[0030] In one or more embodiments, when the distance L7 is defined as the distance between the first center point, which is the center point of the region where the user actually grips the first gripping portion in the axial direction, which is the direction in which the rotation axis of the circular saw blade extends, and the second center point, which is the center point of the second gripping portion, and the distance L9 is defined as the distance between the first center point and the second center of gravity, which is the center of gravity of the battery when the battery is mounted on the battery mounting portion, in the axial direction, the value of L9 / L7 may be 1.3 or more and 1.5 or less. According to this configuration, the weight balance when the user holds the portable circular saw by gripping the first gripping portion and the second gripping portion is improved.

[0031] In one or more embodiments, the circular saw may be a portable circular saw and may include a base having a through hole through which the circular saw blade can pass. When the side on which the electric motor is located with respect to the base is defined as the upper side and the opposite side is defined as the lower side, the circular saw blade is orthogonal to the base, and in a state where the protruding distance of the circular saw blade penetrating the through hole and protruding downward with respect to the base is maximized, the protruding distance on the lower side of the circular saw blade may be 100 mm or more. According to this configuration, a workpiece with a larger thickness can be cut compared to conventional circular saws.

[0032] In one or more embodiments, in a state where the circular saw blade is orthogonal to the base and the protruding distance of the circular saw blade penetrating the through hole and protruding downward with respect to the base is maximized, the protruding distance on the lower side of the circular saw blade may be 150 mm or more. According to this configuration, a workpiece with an even larger thickness can be cut.

[0033] When the torque of the final output shaft is 5 N / m, the value obtained by multiplying the peripheral speed of the cutting edge of the circular saw blade by the diameter of the circular saw blade may be 10.0 m 2 / s or more. According to this configuration, by rotating a circular saw blade having a sufficient diameter at a sufficient peripheral speed, the workpiece can be cut more efficiently.

[0034] In one or more embodiments, the portable circular saw may include a base having a through-hole through which a circular saw blade can pass. When cutting a workpiece with the circular saw, the forward direction is defined as the side where the circular saw advances, the rearward direction is defined as the opposite direction, the upper side is defined as the side where the electric motor is located with respect to the base, the lower side is defined as the opposite side, the lateral direction is defined as the direction perpendicular to the forward and rearward directions and the up and down directions, the right side is defined as the right side when looking from the rear side to the front side, and the left side is defined as the opposite side. In this configuration, when the user stands on the left side of the circular saw and uses it, the electric motor is not positioned in the user's line of sight with respect to the circular saw blade. As a result, during work with the circular saw, the visibility of the circular saw blade visible between the front part of the fixed cover and the front part of the base, particularly the part where the circular saw blade intersects the scribe line on the workpiece, can be improved.

[0035] In one or more embodiments, the circular saw may include a first handle having a first gripping portion that is at least partially located rearward of the circular saw blade in the forward and rearward direction, a second handle having a second gripping portion that is located forward of the electric motor in the forward and rearward direction and to the right of the circular saw blade in the lateral direction, and a third handle having a third gripping portion that is located to the left of the circular saw blade in the lateral direction. According to this configuration, the user can selectively use the handle to grip according to the user's working posture. For example, the user may use the circular saw by gripping the first gripping portion and the second gripping portion with both hands. Alternatively, the user may use the circular saw by gripping the first gripping portion and the third gripping portion with both hands. Further, since the distance between the first gripping portion and the second gripping portion in the forward and rearward direction is increased, the user can hold the circular saw more stably when using the circular saw by gripping the first gripping portion and the second gripping portion with both hands.

[0036] In one or more embodiments, the third gripping portion may be located in front of the electric motor in the front-rear direction. According to this configuration, since the distance between the first gripping portion and the third gripping portion in the front-rear direction increases, when the user holds the first gripping portion and the third gripping portion with both hands and uses the saw, the saw can be held more stably.

[0037] Hereinafter, with reference to FIGS. 1 to 6, a portable saw (hereinafter simply referred to as a saw) 10 according to an exemplary embodiment will be described in more detail. In the following description, when the user holds the saw 10 in hand and cuts a workpiece to be cut (in other words, when the saw 10 is in the posture during use), the side on which the saw 10 advances (the side on which cutting is advanced by a circular saw blade 35 described later) is defined as the front side of the saw 10, and the opposite direction is defined as the rear side of the saw 10. At this time, the side located vertically upward is defined as the upper side of the saw 10, and the opposite side is defined as the lower side of the saw 10. Further, a direction orthogonal to the front-rear direction and the vertical direction is defined as the left-right direction. Among the left-right directions, the right side when viewed from the rear side to the front side is defined as the right side of the saw 10, and the opposite side is defined as the left side of the saw 10.

[0038] As shown in FIG. 1, the saw 10 includes a base 20 and a main body 30. The base 20 has a substantially rectangular outer shape. The longitudinal direction of the base 20 is the front-rear direction. The base 20 has a flat lower surface for abutting against the workpiece to be cut when cutting the workpiece.

[0039] As shown in FIG. 1, the main body 30 is basically disposed above the base 20. As shown in FIGS. 1 to 4, the main body 30 includes a motor housing 11, a gear housing 12, a first handle 50, a second handle 60, an electric motor 41, a circular saw blade 35, a fixed cover 33, and a movable cover 34.

[0040] A part of the circular saw blade 35 penetrates through the through hole 21 of the base 20 and protrudes below the base 20. The circular saw blade 35, also referred to as a tipped saw blade, has a substantially circular shape. The circular saw blade 35 is configured to rotate about a rotation axis AX extending in the left - right direction by a rotational driving force provided by an electric motor 41 (see FIG. 4). The fixed cover 33 covers the upper part of the circular saw blade 35 in an arc shape. The movable cover 34 covers the circular saw blade 35 below the fixed cover 33. The movable cover 34 is configured to be retractable along the outer peripheral edge of the circular saw blade 35 and is normally biased by a biasing member (not shown) toward the position shown in FIG. 1. When the Marunoko 10 is in use, it is pressed against the material to be cut and retracts rearward, thereby exposing the portion of the circular saw blade 35 located below the base 20.

[0041] As shown in FIGS. 2 and 3, the motor housing 11 is disposed on the left side of the fixed cover 33. An electric motor 41 for providing a rotational driving force to the circular saw blade 35 is housed within the motor housing 11. A battery mounting portion 13 (see FIG. 3) configured to detachably mount a battery 14 (see FIG. 2) for supplying power to the electric motor 41 is formed at the rear edge of the motor housing 11. The battery mounting portion 13 includes an electrical terminal for electrically connecting to the battery 14 and a guide groove that engages with a convex portion of the battery. In the present embodiment, the battery mounting portion 13 is configured to be able to mount the battery 14 by sliding the battery 14 along the guide groove from above downward. As shown in FIG. 2, by mounting the battery 14 such that the longitudinal direction of the battery 14 coincides with the vertical direction, the center of gravity of the battery 14 during mounting can be positioned more forward compared to other layouts.

[0042] As shown in FIG. 3, the gear housing 12 is disposed between the fixed cover 33 and the motor housing 11 in the left-right direction. Inside the gear housing 12, a mechanical mechanism (for example, a speed reduction mechanism 43, a spindle 46, etc. described below) for transmitting the rotational driving force of the electric motor 41 to the circular saw blade 35 is accommodated. As shown in FIG. 4, the motor shaft 42 of the electric motor 41 extends in the left-right direction. Further, below the motor shaft 42, a spindle 46 extends in parallel with the motor shaft 42. The spindle 46 extends rightward from inside the gear housing 12 through the right surface of the gear housing 12 and the left surface of the fixed cover 33, and a circular saw blade 35 is attached to the tip thereof by a fixture 36. The circular saw blade 35 extends so as to be orthogonal to the lower surface of the base 20.

[0043] As shown in FIG. 4, the motor shaft 42 is operably connected to the spindle 46 via a speed reduction mechanism 43. The speed reduction mechanism 43 includes a driving gear 44 attached around the motor shaft 42 and a driven gear 45 attached around the spindle 46. The speed reduction mechanism 43 reduces the rotational driving force of the electric motor 41 at a reduction ratio determined based on the gear ratio between the driving gear 44 and the driven gear 45, and transmits it to the spindle 46 and thus to the circular saw blade 35.

[0044] As shown in FIGS. 2 and 3, the first handle 50 is in the form of a loop-shaped loop handle. The first handle 50 extends cylindrically along the arc shape of the fixed cover 33 at the upper edge portion on the rear side of the fixed cover 33 so that a gap (gripping space) is formed between the fixed cover 33 and the first handle 50. As a result, a first gripping portion 51 into which a finger can be inserted and gripped is formed on the first handle 50. The first gripping portion 51 is a portion that extends cylindrically with substantially the same diameter and is intended to be gripped by hand by the user when using the pruning saw 10. A switch lever 55 for operating the start and stop of the electric motor 41 is provided at the front edge portion on the upper side of the first gripping portion 51. For this reason, the user will grip with the hand at a position offset upward in the first gripping portion 51 so that the finger can reach the switch lever 55.

[0045] As shown in FIGS. 2 and 3, the second handle 60 is disposed in front of the first handle 50. In the present embodiment, the second handle 60 is in the form of a loop-shaped loop handle. However, it may be in the form of a rod handle that extends linearly from the left surface of the fixed cover 33 toward the left side. The second handle 60 extends cylindrically so as to bridge a portion on the left surface of the fixed cover 33 that is in front of the electric motor 41 and the upper edge portion on the front side of the motor housing 11. A portion of the second handle 60 that extends in the left-right direction with substantially the same diameter functions as a second gripping portion 61 that is intended to be gripped by hand by the user when using the pruning saw 10.

[0046] When using the pruning saw 10, when the user grips and lifts the first gripping portion 51 of the first handle 50 and the second gripping portion 61 of the second handle 60 with the hand and presses the switch lever 55, the circular saw blade 35 rotates by the driving force of the electric motor 41. In this state, the user brings the lower surface of the base 20 (the portion in front of the circular saw blade 35) into contact with the material to be cut and moves the pruning saw 10 forward. As a result, the cutting of the material to be cut proceeds in the moving direction of the pruning saw 10 by the circular saw blade 35 that protrudes downward beyond the lower surface of the base 20.

[0047] As shown in FIGS. 1 and 2, an angular plate 22 and a fixed lever 23 are attached to the front edge portion. A bracket 24 having a bifurcated shape is attached to the rear surface of the angular plate 22. As shown in FIG. 1, the support shaft 25 is supported by the bracket 24 in a state of passing through the bracket 24 and the front edge portion of the fixed cover 33 disposed between the bifurcated shapes of the bracket 24. With such a configuration, the main body portion 30 is supported by the support shaft 25 on its front side, and is swingable with respect to the base 20 about the support shaft 25.

[0048] The main body portion 30 is supported by a depth guide 26 on its rear side. The swing position (i.e., cutting depth) of the main body portion 30 (circular saw blade 35) with respect to the base 20 can be adjusted by the depth guide 26 and the fixed lever 27. Since such a structure is well known, the description thereof is omitted here.

[0049] Furthermore, the main body portion 30 (circular saw blade 35) is configured to be tiltable with respect to the base 20 about a tilt axis extending in the front-rear direction. According to this configuration, the workpiece to be cut can be cut obliquely. Such a tilting operation is realized by using the angular plate 22 and the fixed lever 23. Since the structure for tilting using the angular plate 22 is well known, the description thereof is omitted.

[0050] In the above-described circular saw 10, a circular saw blade having a diameter of 300 mm or more and 460 mm or less is used as the circular saw blade 35. According to this configuration, the radius of curvature of the circular saw blade 35 is larger than that of a battery-powered circular saw equipped with a conventional small-diameter (e.g., diameter 125 mm) circular saw blade. Therefore, even a workpiece having a large cross section can be efficiently cut. The diameter of the circular saw blade 35 may be 360 mm or more and 460 mm or less. By doing so, the cutting efficiency can be further improved. In the present embodiment, a circular saw blade of 415 mm is disclosed as an example.

[0051] Furthermore, the miter saw 10 may be configured such that the circular saw blade 35 rotates at a peripheral speed of 25.0 m / s or more under load. According to this configuration, even a workpiece having a large cross-section can be efficiently cut at a sufficient peripheral speed. The peripheral speed under load may be 28.0 m / s or more. By doing so, the cutting efficiency can be further improved. In this embodiment, a peripheral speed under load of 29.7 m / s is disclosed as an example.

[0052] Furthermore, the miter saw 10 may be configured such that the circular saw blade 35 rotates at a peripheral speed of 70.0 m / s or less under no load. According to this configuration, the difference in the peripheral speed of the circular saw blade 35 between no load and load can be reduced. Therefore, the behavior of the miter saw 10 when starting to cut the workpiece becomes stable. As a result, the usability for the user is improved, and the cut surface of the workpiece can be made flatter. The peripheral speed under no load may be 50.0 m / s or less. By doing so, the difference in the peripheral speed of the circular saw blade 35 between no load and load can be further reduced. In this embodiment, a peripheral speed under no load of 45.6 m / s is disclosed as an example.

[0053] Furthermore, the miter saw 10 may be configured to rotate such that the force at the cutting edge of the circular saw blade 35 under load becomes 20.0 N or more. According to this configuration, even a workpiece having a large cross-section can be efficiently cut by applying sufficient force to the workpiece. The force at the cutting edge of the circular saw blade 35 under load may be 30.0 N or more. According to this configuration, the workpiece can be cut more efficiently. In this embodiment, a cutting edge force under load of 40.5 N is disclosed as an example.

[0054] Furthermore, as the battery 14, a battery having a rated voltage of 18 V or more and 80 V or less may be used. According to this configuration, even a workpiece having a large cross-section can be efficiently cut with sufficient battery output. The rated voltage of the battery 14 may be 36 V. By doing so, both the compactification (weight reduction) and high output of the miter saw 10 can be achieved with a good balance.

[0055] Furthermore, the reduction ratio of the speed reduction mechanism 43 may be set to 7 or more. According to this configuration, even a workpiece having a large cross-section can be efficiently cut with sufficient torque.

[0056] Hereinafter, various exemplary features regarding the layout of the Marunoko 10 will be described. In the following description, the features in a state where the cutting depth of the circular saw blade 35 is set to the maximum value by the depth guide 26 and the circular saw blade 35 is set parallel to the vertical direction when viewed in the front-rear direction will be referred to. However, the Marunoko 10 may be configured so that the various features described below also apply when the cutting depth of the circular saw blade 35 is set to any value between the minimum value and the maximum value, and when the circular saw blade 35 is angled at any angle with respect to the vertical direction when viewed in the front-rear direction. Alternatively, the Marunoko 10 may be configured so that at least some of the various features described below apply only when the cutting depth of the circular saw blade 35 is set to a specific value between the minimum value and the maximum value, and / or when the circular saw blade 35 is angled at a specific angle with respect to the vertical direction when viewed in the front-rear direction.

[0057] In the present embodiment, as shown in FIGS. 5 and 6, when the battery 14 is attached to the battery attachment portion 13, the battery 14 is positioned between the front edge portion 52 of the first grip portion 51 of the first handle 50 and the front edge portion 62 of the second grip portion 61 of the second handle 60 in the front-rear direction. Here, the front edge portion 52 is the portion located at the rearmost side in the first half region 54 (shown by hatching in FIG. 3). The first half region 54 is a region of a circumferential half portion (the half portion of the outer peripheral surface of the cylindrical body closer to the rotation axis AX) of the first grip portion 51 of a cylindrical body having substantially the same diameter and facing the rotation axis AX of the circular saw blade 35. In FIG. 3, only the left half of the first half region 54 is visible. Also, the front edge portion 62 is the portion located at the foremost side in the second half region 64 (shown by hatching in FIG. 3). The second half region 64 is a region of a circumferential half portion (the half portion of the outer peripheral surface of the cylindrical body closer to the rotation axis AX) of the second grip portion 61 of a cylindrical body having substantially the same diameter and facing the rotation axis AX of the circular saw blade 35. In FIG. 3, only the rear half of the second half region 64 is visible.

[0058] When the diameter of the circular saw blade 35 is increased as in this embodiment, not only does the weight of the circular saw blade 35 increase, but the battery 14, which is a heavy object, also needs to have a higher output. For this reason, when the same arrangement as that of a conventional circular saw with a small-diameter circular saw blade is adopted, the weight balance when the user holds the circular saw 10 by gripping the first grip portion 51 and the second grip portion 61 deteriorates. However, according to the above-described arrangement, since the heavy battery 14 is positioned between the front edge portion 52 of the first grip portion 51 and the front edge portion 62 of the second grip portion 61 (that is, between the rearmost portion and the foremost portion of the portions of the first grip portion 51 and the second grip portion 61 that are intended to be gripped by the hand), even if the diameter of the circular saw blade 35 is increased, the weight balance when the user holds the circular saw 10 by gripping the first grip portion 51 and the second grip portion 61 is improved. Therefore, the user can stably hold the circular saw 10 with less force.

[0059] Furthermore, in the present embodiment, as shown in FIG. 5, when the battery 14 is mounted on the battery mounting portion 13, the center of gravity 15 of the Marunoko (the center of gravity in the state where the battery 14 is mounted) is located below the lower edge of the first gripping portion 51 and the lower edge of the second gripping portion 61 in the vertical direction. Also with such an arrangement, the weight balance when the user holds the Marunoko 10 by gripping the first gripping portion 51 and the second gripping portion 61 is improved.

[0060] Furthermore, in the present embodiment, as shown in FIG. 5, when the battery 14 is mounted on the battery mounting portion 13, the center of gravity 16 of the battery 14, which is a heavy object, is located below the lower edge of the first gripping portion 51 and the lower edge of the second gripping portion 61 in the vertical direction. Also with such an arrangement, the weight balance when the user holds the Marunoko 10 by gripping the first gripping portion 51 and the second gripping portion 61 is improved.

[0061] Furthermore, in the present embodiment, the first gripping portion 51, the second gripping portion 61, the center of gravity 15 of the Marunoko, and the center of gravity 16 of the battery 14 are arranged so as to satisfy the conditions described below. Specifically, first, as shown in FIGS. 5 and 6, the center point of the region where the user actually grips the first gripping portion 51 of the first gripping portion 51 is defined as the first center point 53. Also, the center point of the second gripping portion 61 is defined as the second center point 63. In actuality, when the user grips the first gripping portion 51, the user will grip the position where the fingers of the hand holding the first gripping portion 51 reach the switch lever 55 (that is, the position near the front edge of the first gripping portion 51). The first center point 53 is the center point determined by focusing only on the region where the user actually grips the first gripping portion 51 at that time.

[0062] Furthermore, as shown in FIG. 5, the distance between the first center point 53 and the second center point 63 in the front-rear direction is defined as distance L1, and the distance between the first center point 53 and the center of gravity 15 of the Marunoko in the front-rear direction is defined as distance L2. Furthermore, as shown in FIG. 5, the distance between the first center point 53 and the second center point 63 in the vertical direction is defined as distance L3, and the distance between the first center point 53 and the center of gravity 15 of the Marunoko in the vertical direction is defined as distance L4. Furthermore, as shown in FIG. 5, the distance between the first center point 53 and the center of gravity 16 of the battery 14 in the front-rear direction is defined as distance L5, and the distance between the first center point 53 and the center of gravity 16 of the battery 14 in the vertical direction is defined as distance L6.

[0063] Furthermore, as shown in FIG. 6, the distance L7 between the first center point 53 and the second center point 63 in the left-right direction (in other words, the direction in which the rotation axis AX of the circular saw blade 35 extends) is defined, the distance between the first center point 53 and the center of gravity 15 of the Marunoko in the left-right direction is defined as distance L8, and the distance between the first center point 53 and the center of gravity 16 of the battery 14 in the left-right direction is defined as distance L9.

[0064] The first examples of the design dimensions of the distances L1 to L9 at this time are shown in FIGS. 5 and 6, the second examples are shown in FIGS. 7 and 8, and the third examples are shown in FIGS. 9 and 10, respectively. The unit of the dimensions shown is "mm". Specifically, in the first example, the distance L1 is 323.5 mm, the distance L2 is 192.7 mm, the distance L3 is 51.3 mm, the distance L4 is 184.0 mm, the distance L5 is 49.0 mm, the distance L6 is 148.6 mm, the distance L7 is 87.0 mm, the distance L8 is 48.1 mm, and the distance L9 is 117.9 mm. In the second example, the distance L1 is 323.5 mm, the distance L2 is 199.9 mm, the distance L3 is 51.3 mm, the distance L4 is 185.8 mm, the distance L5 is 59.0 mm, the distance L6 is 151.4 mm, the distance L7 is 87.0 mm, the distance L8 is 45.1 mm, and the distance L9 is 117.9 mm. In the third example, the distance L1 is 323.5 mm, the distance L2 is 204.2 mm, the distance L3 is 51.3 mm, the distance L4 is 187.3 mm, the distance L5 is 67.5 mm, the distance L6 is 160.1 mm, the distance L7 is 87.0 mm, the distance L8 is 43.2 mm, and the distance L9 is 117.9 mm. In the first example, the capacity of the battery 14 is 8 Ah, in the second example, the capacity of the battery 14 is 5 Ah, and in the third example, the capacity of the battery 14 is 4 Ah.

[0065] In any of the first to third examples, the distances L1 to L9 satisfy the following formulas (1) to (4). 0.5 ≦ L2 / L1 ≦ 0.7 ···(1) 3.4 ≦ L4 / L3 ≦ 3.8 ···(2) 0.1 ≦ L5 / L1 ≦ 0.3 ···(3) 2.8 ≦ L6 / L3 ≦ 3.2 ···(4) 0.4 ≦ L8 / L7 ≦ 0.7···(5) 1.3 ≦ L9 / L7 ≦ 1.5···(6) Even when such conditions are satisfied, the weight balance is improved when the user holds the first gripping part 51 and the second gripping part 61 and holds the Marunoko 10. Note that the layout of the Marunoko 10 may be determined so as to satisfy at least one of the above (1) to (6).

[0066] Hereinafter, with reference to FIGS. 11 to 17, only the differences from the first embodiment will be described for the second embodiment. As is clear from FIGS. 12 and 13, in the Marunoko 110 according to the second embodiment, in contrast to the Marunoko 10 (see FIG. 3) in which the circular saw blade 35 is located on the right side with respect to the electric motor 41, the circular saw blade 35 is located on the left side with respect to the electric motor 41 (motor housing 11). According to this layout, when the user stands on the left side of the Marunoko 110 and uses the Marunoko, the motor housing 11 is not located on the user's line of sight with respect to the circular saw blade 35. Also, in the left-right direction, the circular saw blade 35 is located closer to the user. Therefore, during the operation with the Marunoko 110, the visibility of the circular saw blade 35 visible between the front part of the fixed cover 33 and the front part of the base 20, particularly the part where the circular saw blade 35 intersects the scuff line on the workpiece, can be improved.

[0067] As shown in FIGS. 11 to 16, the Marunoko 110 includes a third handle 170 in addition to the first handle 50 and the second handle 60. The shape of the first handle 50 and the position of the first handle 50 with respect to the base 20 are the same as in the first embodiment. That is, the first handle 50 is located at the rear and upper edge of the fixed cover 33, and the first gripping part 51 of the first handle 50 is located at least partially behind the circular saw blade 35.

[0068] The second handle 60 includes a second gripping portion 61, similar to the first embodiment. The second handle 60 extends in a tubular shape so as to span a portion on the right side of the fixed cover 33 that is in front of the electric motor 41 and the upper front edge of the motor housing 11. That is, the second handle 60 is located on the right side with respect to the circular saw blade 35, in contrast to the Marunoko 10 according to the first embodiment. Also, the second gripping portion 61 of the second handle 60 is located in front of the electric motor 41 (motor housing 11). This is the same as in the first embodiment.

[0069] In this embodiment, the third handle 170 is in the form of a rod handle. The third handle 170 is located on the left side of the circular saw blade 35. In other words, the third handle 170 is located on the opposite side of the second handle 60 with respect to the circular saw blade 35. As shown in FIGS. 11, 13, and 15, the third handle 170 extends linearly from the left side surface located on the upper edge of the fixed cover 33 toward the left. In this embodiment, the third handle 170 is located at substantially the same position as the electric motor 41 in the front-rear direction. The third handle 170 includes a third gripping portion 171 that can be gripped by the user. In this embodiment, the proximal end (right end) of the third handle 170 is screwed into a screw hole formed in the fixed cover 33. That is, the third handle 170 is removable. However, the third handle 170 may be non-removably connected to the fixed cover 33. Also, the third handle 170 may be in any form. For example, instead of the form of a rod handle, it may be in the form of a loop handle such as the first handle 50 or the second handle 60.

[0070] According to such a miter saw 110, the user can properly use the handles to be gripped according to the user's working posture. For example, the user may stand on the right side of the miter saw 110 and use the miter saw 110 by gripping the first gripping portion 51 and the second gripping portion 61 with both hands respectively. Alternatively, the user may stand on the left side of the miter saw 110 and use the miter saw 110 by gripping the first gripping portion 51 and the third gripping portion 171 with both hands respectively. Further, according to the miter saw 110, since the second gripping portion 61 is located on the front side of the electric motor 41, the distance between the first gripping portion 51 and the second gripping portion 61 in the front-rear direction becomes large. Therefore, when the user uses the miter saw 110 by gripping the first gripping portion 51 and the second gripping portion 61 with both hands respectively, the miter saw 110 can be held more stably.

[0071] Further, in the miter saw 110, in a state where the circular saw blade 35 is orthogonal to the base 20 and the protruding distance of the circular saw blade 35 protruding from the base 20 is maximum, the protruding distance L10 (see FIG. 11) of the circular saw blade 35 below the base 20 is 100 mm or more. According to this configuration, a workpiece having a large thickness can be cut as compared with a conventional miter saw. The protruding distance L10 may be 150 mm or more. By doing so, a workpiece having a larger thickness can be cut. In the present embodiment, a protruding distance of 158 mm is disclosed as an example.

[0072] Further, in the miter saw 110, when the torque of the spindle 46 is 5 N / m, the peripheral speed of the cutting edge of the circular saw blade 35 is 32.4 m / s. At this time, the value obtained by multiplying the peripheral speed of the cutting edge of the circular saw blade 35 by the diameter of the circular saw blade 35 (hereinafter simply referred to as the product) is 0.415 m (= 415 mm) × 32.4 m / s = 13.4 m 2 / s. Since the larger the diameter of the circular saw blade 35, the closer it is to linear motion, the less the power transmission loss, and thereby the higher the cutting efficiency. Therefore, if this product is 6.0 m 2 / s, the workpiece can be cut efficiently as compared with a conventional miter saw. This product may be 10.0 m 2 / s or more. By doing so, the cutting efficiency can be further increased.

[0073] FIG. 17 shows the difference in product in the Marunoko 110 and the conventional Marunoko. The straight line indicated by the solid line corresponds to the Marunoko 110 according to the present embodiment (the rated output of the battery 14 is 36 V, and the diameter of the circular saw blade 35 is 415 mm), and plots the product when the torque of the spindle 46 is 2, 7, 10 N / m, and shows the result of obtaining the approximate straight line. The straight line indicated by the one-dot chain line corresponds to the conventional Marunoko (the rated output of the battery is 36 V, and the diameter of the circular saw blade is 165 mm), and plots the product when the torque of the spindle is 2, 4 N / m, and shows the result of obtaining the approximate straight line. The straight line indicated by the two-dot chain line corresponds to the conventional Marunoko (the rated output of the battery is 18 V, and the diameter of the circular saw blade is 125 mm) equipped with the technology described in Patent Document 1, and plots the product when the torque of the spindle is 1, 2 N / m, and shows the result of obtaining the approximate straight line. Generally, since the Marunoko is used in a state where the torque of the spindle is about 4 to 7 N / m, if the product when the torque of the spindle 46 is 5 N / m is used as an index value, the cutting efficiency can be evaluated favorably.

[0074] Hereinafter, with reference to FIG. 18, only the differences from the second embodiment will be described for the third embodiment. The Marunoko 210 according to the third embodiment is different from the second embodiment only in the position of the third handle 170. Specifically, the third handle 170 is attached to the fixed cover 33 at a position in front of the electric motor 41 (motor housing 11). The fixed cover 33 is provided with a protruding portion 33a that protrudes upward at the attachment position of the third handle 170. By attaching the third handle 170 to this protruding portion 33a, the third handle 170 can be provided outside the cutting edge of the circular saw blade 35, and interference between the circular saw blade 35 and the third handle 170 can be avoided. According to the present embodiment, the distance in the front-rear direction between the first grip portion 51 and the third grip portion 171 is larger than that in the second embodiment. Therefore, when the user holds the Marunoko 210 by grasping the first grip portion 51 and the third grip portion 171 with both hands, the Marunoko 210 can be held more stably.

[0075] As described above, some embodiments of the present invention have been explained. However, the above-described embodiments are for facilitating the understanding of the present invention and do not limit the present invention. The present invention can be changed and improved without departing from its gist, and equivalents thereof are included in the present invention. Also, within the range where at least a part of the above-described problems can be solved, or within the range where at least a part of the effects can be achieved, any combination or omission of each form element described in the claims and the specification is possible.

[0076] For example, each of the features of the specifications of the above-described Marunoko 10 (such as the diameter of the circular saw blade, the peripheral speed of the circular saw blade, the force at the tip of the circular saw blade, the rated voltage of the battery 14, the reduction ratio of the speed reduction mechanism 43, etc.) and each of the features of the various layouts of the Marunoko 10 can be adopted individually, separated from other features.

[0077] Furthermore, the specifications of the above-described Marunoko 10 are applicable not only to the portable Marunoko but also to a desktop Marunoko or a slide Marunoko that uses a battery as a power source.

[0078] The correspondence between the components of the above-described embodiment and the components of the present invention is shown below. However, each component of the embodiment is merely an example and does not limit the components of the present invention. The marunoko 10 is an example of "marunoko". The circular saw blade 35 is an example of "circular saw blade". The electric motor 41 is an example of "electric motor". The battery mounting portion 13 is an example of "battery mounting portion". The battery 14 is an example of "battery". The speed reduction mechanism 43 is an example of "speed reduction mechanism". The first handle 50 is an example of "first handle". The first gripping portion 51 is an example of "first gripping portion". The second handle 60 is an example of "second handle". The second gripping portion 61 is an example of "second gripping portion". The front edge portion 52 is an example of "the front edge portion of the first gripping portion". The front edge portion 62 is an example of "the front edge portion of the second gripping portion". The first center point 53 is an example of "first center point". The second center point 63 is an example of "second center point". The center of gravity 15 is an example of "first center of gravity". The spindle 46 is an example of "final output shaft".

Explanation of Reference Numerals

[0079] 10... Portable marunoko 11... Motor housing 12... Gear housing 13... Battery mounting portion 14... Battery 15... Center of gravity of marunoko 16... Center of gravity of battery 20... Base 21... Through hole 22... Angular plate 23... Fixed lever 24... Bracket 25... Support shaft 26... Depth guide 27... Fixed lever 30... Main body portion 33... Fixed cover 33a... Protrusion 34... Movable cover 35... Circular saw blade 36... Fixture 41... Electric motor 42... Motor shaft 43... Reduction mechanism 44... Driving gear 45... Driven gear 46... Spindle 50... First handle 51... First gripping part 52... Front edge part 53... First center point 54... First half region 55... Switch lever 60... Second handle 61... Second gripping part 62... Front edge part 63... Second center point 64... Second half region AX... Rotation axis line of circular saw blade

Claims

1. It is a circular saw, A rotatable circular saw blade; an electric motor for providing rotational drive to the circular saw blade; a battery mounting section configured to detachably mount a battery for supplying power to the electric motor; Equipped with The diameter of the circular saw blade is 300 mm or more and 460 mm or less. Circular saw.

2. 2. The circular saw according to claim 1, The circular saw is configured so that the circular saw blade rotates at a peripheral speed of 70.0 m / s or less under no load. Circular saw.

3. 3. The circular saw according to claim 2, The circular saw is configured so that the circular saw blade rotates at a peripheral speed of 50.0 m / s or less under no load. Circular saw.

4. 4. The circular saw according to claim 1, The circular saw is configured so that the circular saw blade rotates at a peripheral speed of 25.0 m / s or more under load. Circular saw.

5. 5. The circular saw according to claim 4, The circular saw is configured so that the circular saw blade rotates at a peripheral speed of 28.0 m / s or more under load. Circular saw.

6. 6. The circular saw according to claim 1, The circular saw is configured to rotate so that the cutting force of the circular saw blade under load is 20.0 N or more. Circular saw.

7. 7. The circular saw according to claim 6, The circular saw is configured to rotate so that the cutting force of the circular saw blade under load is 30.0 N or more. Circular saw.

8. 8. The circular saw according to claim 1, The battery is provided. The rated voltage of the battery is 18V or more and 80V or less. Circular saw.

9. 8. The circular saw according to claim 1, The battery is provided. The rated voltage of the battery is 36V. Circular saw.

10. 10. The circular saw according to claim 1, a reduction mechanism configured to reduce the speed of the rotational driving force of the electric motor and transmit the rotational driving force to the circular saw blade; The reduction ratio of the reduction mechanism is 7 or more. Circular saw.

11. A circular saw according to any one of claims 1 to 10, The circular saw is in the form of a portable circular saw; The portable circular saw is a first handle having a first grip portion; A second handle is disposed forward of the first handle and has a second gripping portion, where the direction in which cutting is performed by the portable circular saw is defined as the front side and the opposite side to the front side is defined as the rear side. Equipped with The battery mounting section is configured such that, when the battery is mounted on the battery mounting section, the entire battery is positioned between the front edge of the first gripping section and the front edge of the second gripping section in the front-rear direction. Circular saw.

12. A circular saw according to any one of claims 1 to 10, The circular saw is in the form of a portable circular saw; The portable circular saw is a first handle having a first grip portion; A second handle is disposed forward of the first handle and has a second gripping portion, where the direction in which cutting is performed by the portable circular saw is defined as the front side and the opposite side to the front side is defined as the rear side. Equipped with The center of gravity of the circular saw when the battery is attached to the battery attachment portion is located lower than the lower edge of the first grip portion and the lower edge of the second grip portion in the vertical direction when the portable circular saw is in a position during use. Circular saw.

13. A circular saw according to any one of claims 1 to 10, The circular saw is in the form of a portable circular saw; The portable circular saw is a first handle having a first grip portion; a second handle having a second grip portion and disposed forward of the first handle, the second handle being disposed forward of the first handle when a cutting direction of the portable circular saw is defined as a front side and a rear side is defined as an opposite side of the front side; The battery Equipped with The center of gravity of the battery when the battery is attached to the battery attachment portion is located lower than the lower edge of the first grip portion and the lower edge of the second grip portion in the vertical direction when the portable circular saw is in an orientation during use. Circular saw.

14. A circular saw according to any one of claims 1 to 10, The circular saw is in the form of a portable circular saw; The portable circular saw is a first handle having a first grip portion; A second handle is disposed forward of the first handle and has a second gripping portion, where the direction in which cutting is performed by the portable circular saw is defined as the front side and the opposite side to the front side is defined as the rear side. Equipped with a distance in the front-rear direction between a first center point, which is a center point of an area of ​​the first grip portion where the user actually grips the first grip portion, and a second center point, which is a center point of the second grip portion, is L1, and a distance in the front-rear direction between the first center point and a first center of gravity, which is a center of gravity of the circular saw when the battery is mounted in a battery mounting portion, is L2, a value of L2 / L1 is 0.5 or more and 0.7 or less. Circular saw.

15. A circular saw according to any one of claims 1 to 14, The circular saw is a portable circular saw, a base having a through hole through which the circular saw blade can pass; When the side of the base on which the electric motor is located is defined as an upper side and the opposite side is defined as a lower side, the circular saw blade is perpendicular to the base and passes through the through hole to a maximum extent so that the circular saw blade protrudes downward from the base by a distance of 100 mm or more on the lower side. Circular saw.

16. 16. The circular saw according to claim 15, When the circular saw blade is perpendicular to the base and the circular saw blade passes through the through hole to a maximum extent protruding downward from the base, the protruding distance of the circular saw blade on the downward side is 150 mm or more. Circular saw.

17. It is a circular saw, A rotatable circular saw blade; an electric motor for providing rotational drive to the circular saw blade; a rotatable final output shaft to which the rotational drive force of the electric motor is transmitted, the final output shaft having the circular saw blade attached thereto; a battery mounting section configured to detachably mount a battery for supplying power to the electric motor; Equipped with When the torque of the final output shaft is 5 N / m, the peripheral speed of the cutting edge of the circular saw blade multiplied by the diameter of the circular saw blade is 6.0 m / s. ２ / s or more Circular saw.

18. 18. The circular saw according to claim 17, When the torque of the final output shaft is 5 N / m, the peripheral speed of the cutting edge of the circular saw blade multiplied by the diameter of the circular saw blade is 10.0 m / s. ２ / s or more Circular saw.

19. 19. A circular saw according to claim 17 or claim 18, The circular saw is a portable circular saw, a base having a through hole through which the circular saw blade can pass; When cutting a workpiece with the circular saw, the side on which the circular saw moves is defined as the front side, and the opposite side is defined as the rear side. The side on which the electric motor is located with respect to the base is defined as the upper side, and the opposite side is defined as the lower side. The direction perpendicular to the front-rear direction and the up-down direction is defined as the left-right direction. The right side when looking at the front side from the rear side is defined as the right side, and the opposite side is defined as the left side. The circular saw blade is located on the left side of the electric motor. Circular saw.

20. 20. The circular saw of claim 19, a first handle having a first grip portion located at least partially rearward of the circular saw blade in the front-rear direction; a second handle having a second grip portion located forward of the electric motor in the front-rear direction and to the right of the circular saw blade in the left-right direction; a third handle having a third grip portion located to the left of the circular saw blade in the left-right direction; A circular saw equipped with

21. 21. The circular saw of claim 20, The third grip portion is located forward of the electric motor in the front-rear direction. Circular saw.

Images