JP2012176468A - Cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a cut depth equal to the case where an inner rotor type electric motor is used as a drive source, regarding a cutting machine which uses an outer rotor type electric motor as a drive source, since a core height is increased and a maximum cut depth is reduced in a direct drive system where a rotary blade is directly mounted to an output shaft by utilizing a function of high output when using the outer rotor type electric motor as a drive source for a portable cutting machine which performs cutting by moving along an upper face of a cutting member.SOLUTION: Rotary output of an outer rotor type electric motor 11 is output through a deceleration device 20 to a spindle 25. A core height D0 of the spindle 25 is made lower than a core height D1 of the electric motor 11, and a maximum cut depth of a rotary blade 12 can be set great.

Description

  The present invention relates to a cutting tool using a so-called outer rotor type electric motor as a drive source.

Techniques related to cutting tools using an inner rotor type brushless motor as a drive source are disclosed in the following patent documents. The inner rotor type brushless motor has a rotor (rotor) configured to include a permanent magnet (magnet) including N poles and S poles on the inner side of the motor, and a stator including three-phase stator windings. Have on the outside.
In contrast to the inner rotor type brushless motor, the outer rotor type brushless motor has a rotor (rotor) configured to include a permanent magnet (magnet) including N and S poles on the outside of the motor. A stator having stator windings is provided inside the motor.
When the outer rotor type brushless motor and the inner rotor type brushless motor are compared with the same size of the motor including the rotor and the stator, the surface area of the magnet attached to the outer rotor is larger than the inner rotor. The outer rotor type brushless motor can take a larger torque.
For this reason, it is possible to reduce the size of the outer rotor type brushless motor compared to the inner rotor type without increasing the torque (while maintaining the same torque), or when the size is not reduced but is equivalent. Can achieve a low rotation and high torque compared to the inner rotor type.

JP 2011-20205 A

While higher power of the cutting tool is demanded in the market, the conventional cutting tool has output by increasing the size of the motor (lengthening the motor in the axial direction).
However, there is a problem that workability is impaired by lengthening the motor in the axial direction. As the handle portion is closer to the saw blade near the center of gravity of the product, the workability is better. However, by increasing the length in the motor shaft direction, the center of gravity position of the product moves away from the blade, that is, the handle portion provided at the position of the center of gravity is separated from the blade, and workability is impaired.
The present invention can reduce the size of the motor while maintaining the output of the motor as compared with the inner rotor type brushless motor. In particular, by mounting an outer rotor type brushless motor capable of shortening the axial length of the motor, an object is to increase motor power without impairing workability.

The above problems are solved by the following invention.
A first invention includes a base to be brought into contact with a cutting material, and a tool main body supported on an upper portion of the base. The tool main body is an outer rotor type electric motor as a drive source for rotating the rotary blade, and the electric motor. It is a cutting tool provided with the reduction gear which decelerates the rotational output of a motor and outputs it to the spindle which attached the rotary blade.
According to the first invention, the rotation output of the electric motor is transmitted to the spindle to which the rotary blade is attached via the reduction gear. Since an outer rotor type electric motor is used as a driving source, the motor output and the size in the radial direction can be reduced while maintaining the motor output and the radial size as compared with the case where an inner rotor type brushless motor is used as a driving source. (Thinning) can be achieved. By reducing the thickness of the electric motor, the center of gravity of the cutting tool in the axial direction of the cutting tool and the handle can be set closer to the rotary blade side, thereby making the operability of the cutting tool easier during cutting work. In addition, the weight balance in the motor axis direction can be achieved and it can be easily carried, so that the workability (operability) and the handleability (portability) of the cutting tool can be improved.
Moreover, since an output larger than that of the inner rotor type motor can be obtained by using an electric motor having an equivalent size, motor power can be increased without impairing the workability of the cutting tool.
In a second aspect based on the first aspect, the speed reducer is configured to rotate the output of the electric motor by meshing the driving side gear and the driven side gear, or by placing a transmission belt between the driving side pulley and the driven side pulley. Is a cutting tool configured to decelerate.
According to the second aspect of the invention, the rotation output of the electric motor is reduced and output to the spindle by the gear meshing reduction device, or the rotation output of the electric motor is reduced and output to the spindle by the belt transmission type reduction device. The The outer rotor type electric motor as a drive source is decelerated by the reduction device, and the rotary blade is rotated at an appropriate rotation speed.
Further, by using this type of reduction device, the rotation center (spindle) of the rotary blade can be displaced downward relative to the output axis of the electric motor so that it can be brought closer to the base. The cutting depth with respect to can be set large.
According to a third aspect, in the first or second aspect, the tool body includes a handle portion that is gripped by a user, and the handle portion rotates more than the center of the width dimension in the motor axial direction of the cutting tool. It is the cutting tool arrange | positioned at the blade side.
According to the third invention, the handle portion is arranged at a position very close to the rotary blade, so that the operator's operation force can be efficiently added to the rotary blade, thereby improving the workability of the cutting tool ( Operability) and handleability (portability) can be improved.
According to a fourth aspect of the present invention, in any one of the first to third aspects, the tool body includes a handle portion gripped by a user, and an interval L1 between the handle portion and the rotary blade in the motor axial direction. Is a cutting tool set to 40 mm to 65 mm.
According to the fourth invention, the handle portion is arranged at a position very close to the rotary blade, so that the operator's operation force can be efficiently applied to the rotary blade, thereby improving the workability of the cutting tool ( Operability) and handleability (portability) can be improved.
The distance between the handle portion and the rotary blade can be set within a range of 40 mm to 65 mm. By using an outer rotor type electric motor as a drive source, the length of the electric motor can be shortened, so that the position of the center of gravity of the cutting tool can be set closer to the rotary blade, and in turn the rotation of the handle portion. The space | interval between blades can be made small and workability | operativity (operability) and handling property (portability) of the said cutting tool can be improved.
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the tool body includes a handle portion gripped by a user, and an interval L1 between the handle portion and the rotary blade in the motor axial direction. Is a cutting tool that is 30 percent or less of the diameter of the rotating blade.
According to the fifth invention, since the handle portion is disposed at a position very close to the rotary blade with respect to the position in the motor axial direction in relation to the size (diameter) of the rotary blade, the workability (operation of the cutting tool) Property) and handleability (portability).
A sixth invention is a cutting according to any one of the first to fifth inventions, wherein a ratio (H / L) of the overall height dimension H of the cutting tool to the overall width dimension L in the motor axial direction is at least 1.1. It is a tool.
According to the sixth invention, since the overall width dimension L in the motor axial direction is smaller than the overall height dimension H of the cutting tool, the center of gravity position of the cutting tool in the motor axial direction is set to a position close to the rotary blade. Thus, the workability (operability) and handling (portability) of the cutting tool when the tool body is provided with a handle portion can be improved.
According to a seventh invention, in any one of the first to sixth inventions, the tool body is provided with a handle portion to be gripped by a user, and the center of gravity position of the cutting tool corresponds to the handle in the motor axial direction position. It is the cutting tool aligned with the part.
According to the seventh invention, since the position of the center of gravity is aligned with the handle portion with respect to the position in the motor axial direction, it is possible to improve the weight balance of the cutting tool when the user grips the handle portion, As a result, the user can easily grasp and carry the cutting tool without applying excessive force to the hand, and can perform a cutting process.

1 is an overall front view of a cutting tool according to an embodiment of the present invention. 1 is an overall plan view of a cutting tool according to an embodiment of the present invention. It is the (III)-(III) arrow directional view of FIG. 1, Comprising: It is a longitudinal cross-sectional view of the cutting tool which concerns on embodiment of this invention. It is the whole rear view which looked at the cutting tool which concerns on embodiment of this invention from the arrow (IV) direction in FIG. It is a figure which shows 2nd Embodiment of this invention, and is a longitudinal cross-sectional view of the cutting tool provided with the belt transmission type reduction gear.

Next, an embodiment of the present invention will be described with reference to FIGS. 1-3 has shown the cutting tool 1 of this embodiment. The cutting tool 1 is a so-called portable marnoko, and includes a flat plate-like base 2 that is brought into contact with the upper surface of the cutting material W, and a tool body 10 supported on the upper portion of the base 2.
The tool body 10 includes an electric motor 11 as a drive source, a reduction device 20 for reducing the rotational output of the electric motor 11, and a circular rotary blade 12 attached to a spindle 25 that is an output shaft of the reduction device 20. ing. The lower side of the rotary blade 12 is protruded from the lower surface of the base 2, and the protruding portion is cut into the cutting material W to be cut. In each figure, the rotary blade 12 is cut into the cutting material by moving the cutting tool 1 in the cutting progress direction indicated by the white arrow. In the following description, with respect to the longitudinal direction of the member or configuration, the cutting progress direction is defined as the front side or the front portion, and the opposite side is defined as the rear side or the rear portion. However, regarding the electric motor 11, the rotating blade 12 side is the front side or the front part in the motor axis J direction, and the opposite side is the back side or the rear part.
As shown in FIG. 3, the electric motor 11 is a brushless motor, which is a so-called outer rotor type electric motor. The electric motor 11 includes a rotor 11c that is rotatably supported on the outer peripheral side of a stator 11b fixed in a motor case 11a. An output shaft 11d is attached to the rotor 11c. The output shaft 11d is rotatably supported via bearings 11f and 11g. The rear side bearing 11 f is attached to the rear part of the motor case 11 a, and the front side bearing 11 g is attached to the speed reduction case 21.
The distance between the axis of the output shaft 11d of the electric motor 11 (motor axis J) and the lower surface of the base 2 is the motor core height D1.
A cooling fan 11e for cooling the motor is attached to the rear portion of the output shaft 11d. A number of exhaust holes (wind windows) 11h to 11h are provided around the cooling fan 11e and in the rear part of the motor case 11a. In contrast, as shown in FIG. 2, intake holes 21 a to 21 a are provided on the rear surface of a speed reduction case 21 of a speed reduction device 20 described later. When the cooling fan 11e is rotated by the activation of the electric motor 11, outside air is introduced from the intake holes 21a to 21a. The introduced outside air (cooling air) flows toward the rear of the motor through the air holes 11n to 11n on the stator 11b side by the wind force, and the electric motor is cooled. The cooling air that has flowed to the rear side of the motor through the air holes 11m to 11m provided at the bottom of the rotor 11c is exhausted to the outside through the exhaust holes 11h to 11h.
The distal end side of the output shaft 11d of the electric motor 11 protrudes from the motor case 11a and enters the speed reduction device 20. The speed reducer 20 is interposed between the electric motor 11 and the blade case 14 that covers the upper half of the rotary blade 12.

The speed reduction device 20 includes a gear meshing type speed reduction mechanism, and includes a drive side gear 22 and a driven side gear 23 in a speed reduction case 21. The drive side gear 22 is attached to the output shaft 11 d of the electric motor 11. A driven gear 23 that meshes with the driving gear 22 is attached to a spindle 25. The front end side of the spindle 25 protrudes into the blade case 14, and the rotary blade 12 is attached to the protruding portion in a state of being sandwiched between the receiving flange 26 and the presser flange 27. The spindle 25 is rotatably supported by the speed reduction case 21 via bearings 25a and 25b.
When the number of teeth Z of the driving side gear 22 is 17 and the number of teeth Z of the driven side gear 23 is 52, the reduction ratio (the number of teeth ratio) is set to about 3.0. For this reason, the rotary blade 12 rotates at about 3,000 revolutions per minute.
The rotation speed of the electric motor 11 is about 15,000 rotations per minute, the number of teeth Z of the driving gear 22 is Z = 9, the number of teeth Z of the driven gear 23 is Z = 47, and the reduction ratio is set to about 5.2. The number of rotations of 12 may be about 2,900 rotations per minute. The former setting can reduce the noise of the electric motor 11, and the latter setting can increase the output.
The rotary blade 12 rotates counterclockwise as viewed from the front. On the front side of the blade case 14, the rotation direction of the rotary blade 12 is indicated by an arrow 14a.
In the speed reducer 20, spur gears are used for the driving side gear 22 and the driven side gear 23, respectively, and the spindle 25 and the output shaft 11d of the electric motor 11 are supported in parallel with each other. Moreover, the spindle 25 is supported on the lower side close to the base 2 side by a dimension (D1-D0) with respect to the output shaft 11d of the electric motor 11. For this reason, the spindle 25 is disposed at a position lower than the so-called direct type motor core height D1 by a distance (D1-D0), and therefore the core height D0 of the rotary blade 12 is set to be small.
As shown in the drawing, the core height D0 of the rotary blade 12 is the rotational center of the rotary blade 12 and the axis of the spindle 25 (with the cutting depth of the rotary blade 12 with respect to the cutting material W being set to the maximum). This corresponds to the distance between the spindle axis S) and the lower surface of the base 2 (the upper surface of the cutting material W).

The tool body 10 is supported on the upper portion of the base 2 via a front tilting support shaft 15 so as to be tiltable up and down. By changing the vertical tilt position of the tool body 10 with respect to the base 2, the projecting dimension of the rotary blade 12 to the lower surface side of the base 2 can be changed, whereby the cutting depth of the rotary blade 12 with respect to the cutting material W can be changed. Can be adjusted. As shown in FIG. 2, the rear side of the tool body 10 is supported by the base 2 via a curved guide member 3 called a depth guide that is attached to the upper portion of the base 2 in an upright state. By tightening the fixing screw 4 inserted through the guide hole 3a of the guide member 3 to the back side of the blade case 14, the tilting position of the tool body 10 with respect to the base 2 is fixed. The fixing screw 4 can be tightened by rotating the operation lever 5 attached to the front end of the back surface in the tightening direction. When the operation lever 5 is rotated to loosen the fixing screw 4, the tool body 10 can be tilted up and down with respect to the base 2, whereby the cutting depth of the rotary blade 12 can be changed.
The lower half of the rotary blade 12 protruding to the lower surface side of the base 2 is covered by the movable cover 16. The movable cover 16 is supported by the blade case 14 so as to be rotatable around the rotary blade 12. As shown in FIG. 1, the tip of the movable cover 16 is brought into contact with the cutting material W, and in this contacted state, the cutting tool 1 is moved in the cutting progress direction indicated by a white arrow in the drawing to rotate the rotary blade 12. Is cut into the cutting material W, whereby the movable cover 16 is gradually opened. A handle 17 is attached to the rear portion of the movable cover 16. The user can grip the handle 17 and rotate the movable cover 16 in the opening direction, thereby facilitating work such as replacement of the rotary blade 12.

A handle portion 30 is provided in the vicinity of the coupling portion between the electric motor 11 and the speed reducer 20. As shown in FIG. 4, the handle portion 30 has a mountain-shaped loop shape extending from the upper portion of the electric motor 11 to the rear portion, and a standing portion 31 that rises upward from the upper portion of the electric motor 11, and an upper portion of the standing portion 31. A main grip portion 32 extending in a downward direction from the rear, and a coupling portion 33 for coupling the rear portion of the main grip portion 32 to the rear portion of the electric motor 11. The main grip portion 33 is a portion that the user holds with one hand, and a switch lever 35 is disposed on the lower surface side thereof. A front grip part 34 that is held by the user with the other hand is provided on the upper part of the standing part 31 so as to protrude forward.
A battery mounting base portion 36 is provided at the rear portion of the main grip portion 32. The battery pack B is mounted on the battery mounting base 36. The battery pack B can be slid upward to be removed from the battery mounting pedestal 36, and conversely slid downward to be attached to the battery mounting pedestal 36. The removed battery pack B can be used repeatedly by charging with a separately prepared charger. The electric motor 11 is activated using the battery pack B as a power source.
A lock lever 37 for locking the rotation of the output shaft 11 d is provided at the front portion of the electric motor 11. When the lock lever 37 is moved in the longitudinal direction, the rotation of the output shaft 11d is locked, whereby the rotation of the spindle 25 is locked to facilitate the operation of exchanging the rotary blade 12.
As shown in FIG. 3, the overall height H between the top portion of the handle portion 30 and the lower end portion of the movable cover 16 in a state where the cutting depth of the rotary blade 12 is set to the maximum, and the cutting tool 1 in the motor axis J direction. The ratio (H / L) to the full width dimension L is set to about 1.6.
Further, the distance L1 between the handle portion 30 and the rotary blade 12 in the motor axis J direction is set to about 30 percent of the diameter d12 of the rotary blade 12.

According to the present embodiment configured as described above, the rotational output of the electric motor 11 is decelerated by the reduction gear 20 and output to the spindle 25. The spindle 25 that is the output shaft of the reduction gear 20 is arranged in parallel to a position close to the base 2 that is lower than the output shaft 11d of the electric motor 11 that is the input shaft by an inter-axis distance D1.
The spindle 25 is disposed on the base 2 side (lower side) of the motor output shaft 11d, and the core height D0 of the rotary blade 12 is smaller than that of the so-called direct drive system. For this reason, the cutting depth of the rotary blade 12 with respect to the cutting material W is compared with the direct drive method (method of not decelerating) in which the rotary blade is directly attached to the output shaft of the electric motor or the spindle arranged coaxially. Can be set large.
Further, according to the cutting tool 1 of the present embodiment, since the outer rotor type electric motor 11 is provided as a driving source, the machine length L0 is smaller than when the inner rotor type electric motor is used as the driving source ( Can be made thinner). Since the machine length L0 of the electric motor 11 is small, the position of the center of gravity of the cutting tool 1 in the motor axis J direction is located closer to the rotary blade 2 side. In the case of the present embodiment, the position in the same direction of the handle portion 30 is set in alignment with the position of the center of gravity in the motor axis J direction. For this reason, the position of the handle portion 30 in the motor axis J direction is set to a position closer to the rotary blade 12 side, and in the present embodiment, the distance between the two is set to L1. In the present embodiment, the distance L1 between the handle portion 30 and the rotary blade 12 is set to about 63 mm, which is smaller than about 73 mm when an inner rotor type electric motor is used as a drive source.
Further, the distance L1 between the handle portion 30 and the rotary blade 12 in the motor axis J direction is set to about 30 percent of the diameter d12 of the rotary blade 12. In this way, the center of gravity of the cutting tool 1 in the direction of the motor axis J can be set closer to the rotary blade 12 side by setting the interval L small with reference to the size of the rotary blade 12. Thus, the workability (operability) and the handleability (portability) of the cutting tool 1 can be improved.
Thus, compared with the case where an inner rotor type motor is used as a drive source, the machine length L0 of the electric motor 11 can be made compact, and the center of gravity position in the same direction of the cutting tool 1 can be brought closer to the rotary blade 12. The handle portion 30 can be aligned with the position of the center of gravity. Since the center of gravity of the cutting tool 1 is positioned below the handle portion 30, when the user carries the cutting tool 1 by holding the main grip portion 32 of the handle portion 30 or moving the cutting tool 1, the cutting tool 1 is cut. It can be easily carried without applying an excessive force to the gripped hand, and can be easily moved and cut without placing a burden on the gripped hand.
In the case of the present embodiment, since the battery pack B having a relatively heavy weight is attached to the rear portion of the handle portion 30, the center of gravity of the cutting tool 1 is aligned below the handle portion 30 so as to have a particularly large effect. An effect can be obtained.
In addition, since the handle portion 30 is disposed at a position closer to the rotary blade 12, a force for pushing the cutting tool 1 in the cutting progress direction can be efficiently applied to the rotary blade 12, thereby burdening the user's hand. It is possible to improve the operability or workability of the cutting tool 1 by reducing the weight. In particular, in the case of the present embodiment, the overall height H between the top of the handle portion 30 and the lower end of the movable cover 16 in the state where the cutting depth of the rotary blade 12 is set to the maximum, and the overall width in the motor axis J direction. Since the ratio (H / L) to L is set to about 1.6, the entire width dimension L in the motor axis J direction is set to be extremely small relative to the total height H, and the cutting tool 1 is connected to the motor axis. Compact in the J direction. By setting the ratio (H / L) to 1.1 or more, the center of gravity of the cutting tool 1 in the motor axis J direction can be positioned closer to the rotary blade 12, thereby Workability (operability) and handleability (portability) can be improved.
By reducing the size of the cutting tool 1 in the direction of the motor axis J from various viewpoints as described above, the position of the handle portion 30 in the direction of the motor axis J is more than the center of the full width dimension of the cutting tool 1. It can arrange | position to the side and the effect mentioned above can be acquired by this.

Various modifications can be made to the embodiment described above. For example, a gear meshing type speed reduction device 20 in which the drive side gear 22 and the driven side gear 23 are meshed is illustrated as a speed reduction device for reducing the rotational output of the electric motor 11 and outputting it to the spindle 25. FIG. As shown, the belt transmission type reduction device 40 can be changed. Since it is the same as that of the cutting tool 1 of above-described 1st Embodiment except the reduction gear 40, the description is abbreviate | omitted using a code | symbol of a peer. In FIG. 5, some members such as the front grip 34 and the battery pack B are omitted.
The speed reducer 40 according to the second embodiment includes a driving pulley 41 attached to the output shaft 11d of the electric motor 11, a driven pulley 42 attached to the spindle 25, and between the driving pulley 41 and the driven pulley 42. A transmission belt 43 is provided around the belt. An appropriate reduction ratio of the reduction gear 50 is set by using a driven pulley 42 having a larger diameter than the driving pulley 41. As in the first embodiment, an outer rotor type electric motor is used for the electric motor 11.
According to the cutting tool 1 of the second embodiment, the rotation output of the electric motor 11 is decelerated and output by the reduction gear 40. The core height D0 of the spindle 25, which is the output shaft of the reduction gear 40, can be set below the core height D1 of the output shaft 11d of the electric motor 11 by a dimension (D1-D0). A large depth of cut with respect to the twelve cutting materials W can be secured.
Further, since the outer rotor type electric motor 11 having a compact machine length L0 is used as a drive source, the cutting tool 1 can be made compact in the motor machine length direction. Since the handle portion 30 can be disposed at a position closer to the rotary blade 12 at the interval L1, it is possible to obtain the same effects as those of the first embodiment.

DESCRIPTION OF SYMBOLS 1 ... Cutting tool 2 ... Base 3 ... Guide member (depth guide), 3a ... Guide hole 4 ... Fixing screw 5 ... Operation lever 10 ... Tool body 11 ... Electric motor (outer rotor type)
11a ... Motor case, 11b ... Stator, 11c ... Rotor, 11d ... Output shaft 11e ... Cooling fan, 11f, 11g ... Bearing, 11h ... Exhaust hole 11m, 11n ... Vent hole J ... Motor axis 12 ... Rotary blade, d12 ... Diameter (size) of rotating blade
14 ... Blade case 15 ... Tilt support shaft 16 ... Movable cover 17 ... Handle 20 ... Reduction gear (gear meshing type)
DESCRIPTION OF SYMBOLS 21 ... Deceleration case, 21a ... Intake hole 22 ... Drive side gear 23 ... Driven side gear 25 ... Spindle 26 ... Receiving flange 27 ... Holding flange S ... Spindle axis (Rotation axis of a rotary blade)
DESCRIPTION OF SYMBOLS 30 ... Handle part 31 ... Standing part 32 ... Main grip part 33 ... Coupling part 34 ... Front grip part 35 ... Switch lever 36 ... Battery mounting base part 37 ... Lock lever 40 ... Reduction gear (belt transmission type)
41 ... Drive side pulley 42 ... Driven side pulley 43 ... Transmission belt B ... Battery pack D1 ... Core height D0 of electric motor ... Core height H of rotating blade (spindle) ... Total height of cutting tool L ... Motor of cutting tool Width dimension L0 in the axial direction ... Motor machine length L1 ... Interval in the motor axial direction between the handle portion and the rotary blade

Claims (7)

A base that abuts on the cutting material, and a tool main body supported on an upper portion of the base, the tool main body being an outer rotor type electric motor as a drive source for rotating the rotary blade, and a rotational output of the electric motor. A cutting tool provided with a reduction gear that decelerates and outputs to a spindle to which the rotary blade is attached. 2. The cutting tool according to claim 1, wherein the speed reducer is configured to rotate the electric motor by meshing the driving side gear and the driven side gear or by passing a transmission belt between the driving side pulley and the driven side pulley. Cutting tool designed to reduce output. 3. The cutting tool according to claim 1, wherein the tool body includes a handle portion gripped by a user, and the handle portion rotates more than a center of a width dimension in a motor axial direction of the cutting tool. Cutting tool placed on the blade side. The cutting tool according to any one of claims 1 to 3, wherein the tool main body includes a handle portion that is gripped by a user, and a motor axial direction between the handle portion and the rotary blade tool is provided. A cutting tool in which the distance L1 is set to 40 mm to 65 mm. The cutting tool according to any one of claims 1 to 4, wherein the tool body includes a handle portion that is gripped by a user, and is arranged in a motor axial direction between the handle portion and the rotary blade. The cutting tool whose space | interval L1 is 30 percent or less of the diameter of the said rotary blade. The cutting tool according to any one of claims 1 to 5, wherein a ratio (H / L) of a total height dimension H of the cutting tool to a total width dimension L in the motor axial direction is 1.1 or more. tool. It is a cutting tool given in any 1 paragraph of Claims 1-6, The above-mentioned tool body is provided with the handle part which a user grasps, and the gravity center position of the cutting tool concerned about the position of the above-mentioned motor axial direction A cutting tool aligned with the handle portion.

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