JP2016209939A - Electric tool - Google Patents

Abstract

An electric power tool capable of efficiently checking the deflection accuracy of a rotating tool is provided. A tabletop cutting machine as an example of an electric tool includes a rotating tool having a side surface orthogonal to a spindle (rotating shaft). The control unit can execute a measurement mode in which the rotating tool 18 is rotated at an ultra-low speed of one rotation for a plurality of seconds by the motor 60, and when checking the deflection accuracy of the rotating tool 18, The measurement mode is executed with the dial gauge 29 applied. [Selection] Figure 4

Description

  The present invention relates to a power tool such as a tabletop cutting machine in which a rotating tool has a plane orthogonal to a rotation axis (spindle).

  A tabletop cutting machine generally includes a base portion having a workpiece mounting surface, a holder portion standing on the base portion and tiltable with respect to the base portion, and supported by the holder portion with respect to the base portion. And a cutting part (round saw part) that can swing up and down. The cutting unit has a motor that rotationally drives a cutting tool (cutting blade) such as a circular saw blade. The rotation of the motor is transmitted to the rotation shaft (spindle) of the rotating tool by a rotation transmission mechanism such as a belt or a gear. The user swings the cutting part rotating the cutting tool downward, and cuts the workpiece placed on the base part.

  In a tabletop cutting machine, the rotating tool needs to be orthogonal to the rotation axis to which it is attached with high accuracy, and the rotation of the rotating tool relative to the plane orthogonal to the rotation axis when rotating is less than a certain level. Desired. The swing accuracy of the rotating tool is confirmed by a method in which a dial gauge is applied to the side surface of the rotating tool and the rotating tool is rotated by hand. Note that the rotating tool attached to the rotating shaft when checking the runout accuracy may be a resin disk for measurement instead of a circular saw blade or the like used in actual work.

JP 2014-14911 A

  In recent years, there has been a movement to employ brushless motors in tabletop cutting machines. When the drive source is a brushless motor, when the rotating tool is rotated by hand, cogging is generated by the magnetic force of the permanent magnet in the brushless motor, and the operation of the rotating tool becomes jerky. For this reason, when checking the swing accuracy of the rotating tool, vibrations caused by such jerky movements are transmitted to the dial gauge, and accurate measurement is difficult and work efficiency is not good. Even if there is no cogging problem, there is room for improvement in terms of work efficiency in the method itself of rotating the rotating tool by hand. Such a problem is not limited to the tabletop cutting machine, and is common to the case of checking the runout accuracy of the rotating tool in other types of electric tools such as a grinder having a rotating tool orthogonal to the rotating shaft (spindle). .

  The present invention has been made in view of such a situation, and an object of the present invention is to provide an electric tool capable of efficiently checking the deflection accuracy of a rotating tool.

One embodiment of the present invention is a power tool. This electric tool
A motor,
A rotating shaft rotated by the motor;
A rotating tool attached to the rotating shaft and having a plane perpendicular to the rotating shaft;
A control unit for driving and controlling the motor,
The control unit is capable of executing a work mode for actual work and a measurement mode for measuring the deflection accuracy of the rotating tool,
The rotating speed of the rotating tool in the measurement mode is lower than the rotating speed of the rotating tool in the work mode.

The rotating tool in the working mode rotates a plurality of times per second,
The rotating tool in the measurement mode may rotate once in a plurality of seconds.

  The rotating direction of the rotating tool in the measurement mode may be opposite to the rotating direction of the rotating tool in the work mode.

  The control unit may stop the motor when the rotating tool is rotated once in the measurement mode.

  A work operation unit for driving the motor in the work mode and a measurement operation unit for driving the motor in the measurement mode may be provided separately from each other.

  The housing further includes a housing for housing the motor, wherein a part of the housing is configured by a cover member that is removable from the housing, and the measurement operation unit is configured to remove the cover member from the housing. It may be operable.

  The controller may stop the motor when the current flowing through the motor becomes a predetermined value or more during execution of the measurement mode.

  The motor may be a brushless motor including a stator having a plurality of stator windings and a rotor having a magnetic body rotatable with respect to the stator.

Another aspect of the present invention is a power tool. This electric tool
A brushless motor comprising a stator having a plurality of stator windings and a rotor having a magnetic body rotatable with respect to the stator;
A rotating shaft rotated by the motor;
A rotating tool attached to the rotating shaft and having a plane perpendicular to the rotating shaft;
A rotation transmission mechanism that transmits the rotation of the rotor to the rotation shaft,
The rotation transmission mechanism may not transmit rotation of the rotating tool in at least one direction to the rotor so that the rotating tool can be rotated without load on the rotor when measuring the deflection accuracy of the plane. .

  The rotation transmission mechanism includes a one-way clutch. When the rotating tool is rotated in the reverse direction, the rotor also rotates. When the rotating tool is rotated in the normal direction, the rotor does not need to rotate.

  It should be noted that any combination of the above-described constituent elements, and those obtained by converting the expression of the present invention between methods and systems are also effective as aspects of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the electric tool which can confirm the runout accuracy of a rotary tool efficiently can be provided.

The side view of the tabletop cutting machine which concerns on Embodiment 1 of this invention. The front view. The side view at the time of confirming the runout accuracy of the rotary tool 18 of the said tabletop cutting machine. The front view which made the same part the cross section. FIG. The principal part top view of the said tabletop cutting machine. The figure which looked at the rotor of the motor 60 of the said tabletop cutting machine from the axial direction. The control block diagram of the said tabletop cutting machine. The principal part sectional drawing which shows the rotation transmission mechanism of the tabletop cutting machine which concerns on Embodiment 2 of this invention. Sectional drawing which shows the rotation transmission mechanism of the tabletop cutting machine which concerns on Embodiment 3 of this invention. The principal part enlarged view of FIG. 10 in a clutch disengagement state.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or equivalent component, member, etc. which are shown by each drawing, and the overlapping description is abbreviate | omitted suitably. In addition, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

Embodiment 1
FIG. 1 is a side view of a tabletop cutting machine according to Embodiment 1 of the present invention. FIG. 2 is a front view of the same. FIG. 3 is a side view of the tabletop cutting machine when checking the runout accuracy of the rotary tool 18. FIG. 4 is a front view with the same section taken as a cross section. FIG. 5 is a perspective view of the main part. FIG. 6 is a plan view of an essential part of the tabletop cutting machine. FIG. 7 is a view of the rotor of the motor 60 of the tabletop cutting machine as seen from the axial direction.

  In the tabletop cutting machine according to the present embodiment, the base portion includes a base 1 that can be placed on a floor surface or the like, and a turntable 2 that is embedded in the center of the base 1 and whose upper surface is substantially flush with the upper surface of the base 1. Have The turntable 2 is rotatably connected to the base 1 via a rotation shaft (not shown) orthogonal to the upper surface of the turntable 2. A workpiece such as wood is placed on the upper surface of the base portion. A pair of fences 3 is provided on the upper surface of the base 1, and a stable cutting operation can be performed by bringing a workpiece into contact with the fence 3. When the turntable 2 is rotated with respect to the base 1, the positions of a holder 5 and a cutting part 11 (described later) connected to the turntable 2 with respect to the fence 3 change. Thereby, the angle (angle seen from the top) of the fence 3 and the side surface of the rotary tool 18 changes, and the workpiece that is in contact with the fence 3 can be cut (angularly cut) at various angles. .

  In the vicinity of the rear end (left side in FIG. 1) of the turntable 2, a holder 5 as a holder portion is erected upward. The holder 5 is connected to the turntable 2 via a holder shaft (inclined shaft) 4 shown in FIG. 2 extending substantially parallel to the side surface of the rotary tool 18 such as a circular saw blade (cutting blade) and the upper surface of the turntable 2. Is done. By making the axis of the holder shaft 4 substantially coincide with the upper surface of the turntable 2, the holder 5 is pivotally supported with respect to the turntable 2 so that the holder shaft 4 can be tilted to the left and right. The tiltable range is, for example, about 45 degrees on the left and right. When the clamp lever 30 is loosened, the holder 5 can be tilted about the holder shaft 4 (the tilt position of the holder 5 can be adjusted). When the clamp lever 30 is tightened, the inclined position of the holder 5 is fixed at an arbitrary position.

  A cutting part (circular saw part) 11 is pivotally supported on the upper part of the holder 5 via a shaft (oscillating shaft) 10. The cutting part 11 can swing up and down with respect to the upper surfaces of the base 1 and the turntable 2 by supporting the shaft 10. Between the holder 5 and the cutting part 11, a spring 12 for biasing the cutting part 11 upward is provided. When the stopper bolt supported by the cutting part 11 comes into contact with the stopper receiving part provided in the holder 5, the swing lower limit position of the cutting part 11 is determined.

  A rotating tool 18 is rotatably supported on the saw blade shaft of the cutting unit 11. The cutting unit 11 includes a saw cover (gear cover) 15 that covers the upper outer periphery of the rotating tool 18 and a protective cover 28 that covers the lower outer periphery of the rotating tool 18. The saw cover 15 is connected to a motor unit 16 and a handle 19 for generating power. The motor unit 16 includes a motor 60 (FIG. 4). The motor 60 is a brushless motor, and includes an output shaft 61, a rotor core 62 made of a magnetic material, a rotor magnet 63, a stator core 64, and a stator coil 65. The rotation of the motor 60 (rotation of the output shaft 61) is transmitted to the spindle (rotary shaft) 32 by a rotation transmission mechanism 33 such as a gear, and the rotating tool 18 attached to the spindle 32 rotates together with the spindle 32. A side surface of the rotating tool 18 is a plane orthogonal to the spindle 32. As shown in FIG. 4, a switch board 75 is provided on the opposite side of the motor 60 from the rotating tool 18. A plurality of switching elements 76 such as FETs and IGBTs are mounted on the switch substrate 75.

  The handle 19 is provided with an operation switch (trigger switch) 31 as a work operation unit that switches whether the motor unit 16 is energized. Moreover, LED17 as an illuminating device is connected to the handle | steering-wheel 19 via the flexible shaft 17a. The LED 17 is a work light that illuminates a material to be cut at hand during cutting work. Furthermore, as shown in FIG. 6, the handle 19 has a laser switch 21 for switching on / off a laser (not shown) that irradiates a cutting line, a light switch 22 for switching on / off the LED 17, a normal rotation switch 23 for measurement, and a measurement switch A reverse switch 24 is provided. The measurement forward rotation switch 23 and the measurement reverse rotation switch 24 as the measurement operation unit are switches that are operated when a measurement mode described later for checking the shake accuracy of the rotating tool 18 is started. As shown in FIG. 6, the measurement forward rotation switch 23 and the measurement reverse rotation switch 24 are covered with a cover 16a as a cover member that is detachably provided on the housing of the motor unit 16 by screwing or the like. When the cover 16a is removed, the operation becomes possible.

  A discharge port 13 to which a hose of a dust collector can be connected is provided at the rear part of the cutting unit 11, and chips and the like generated by the cutting operation can be discharged. The protective cover 28 is provided on the outer periphery of the saw blade shaft so as to be rotatable around the saw blade shaft outside the saw cover 15, and is rotated by the spring (not shown) in the saw blade rotation direction (clockwise direction in FIG. 1), that is, the rotating tool 18. It is urged in the direction to cover. Further, the protective cover 28 rotates counterclockwise when the cutting part 11 swings downward (base part side), specifically, so as to rotate around the saw blade axis in conjunction with the swinging of the cutting part 11. It is engaged with the saw cover 15 by a link mechanism including a link 25, a link support shaft 26, and a protective cover rotating shaft 27 so as to rotate in a direction (a direction in which the rotating tool 18 is exposed).

  The tabletop cutting machine of the present embodiment is capable of cutting at right angles, angle cutting, inclined cutting, and combined cutting of angle cutting and inclined cutting. In order to perform the cutting operation, first, depending on the type of cutting The turntable 2 is rotated to a desired angle, and the clamp lever 30 is operated to set the holder 5 at a desired tilt position. Then, when the handle 19 is gripped and the operation switch 31 provided on the handle 19 is pulled, the operation mode is started by the control unit 50 shown in FIG. 8, the motor unit 16 is driven to rotate, and the rotation of the motor unit 16 is rotated. The rotation tool 18 (a cutting tool such as a circular saw blade in actual work) rotates together with the spindle 32. In this state, the handle 19 is pushed down against the urging force of the spring 12, the cutting portion 11 is swung to the lower limit position, and the workpiece is cut. After the cutting of the workpiece is completed, if the force that the handle 19 is pressed down is weakened, the cutting portion 11 is pushed upward by the spring 12 and returns to the original upper limit position.

  In the tabletop cutting machine of the present embodiment, when checking the runout accuracy of the rotating tool 18, as shown in FIGS. 3 to 5, the protective cover 28 is pushed up by hand, and the dial gauge 29 is placed on the side surface of the rotating tool 18. The rotating tool 18 is rotated at least once, and the swing width of the rotating tool 18 is measured. The dial gauge 29 is erected on the upper surface of the turntable 2 by legs 29a. The rotating tool 18 for checking the runout accuracy may be a resin disk for measurement instead of a cutting tool such as a circular saw blade (cutting blade) used in actual work.

  Conventionally, when checking the runout accuracy of the rotating tool 18, the rotating tool 18 is manually rotated. However, cogging is generated by the magnetic force of the rotor magnet 63 of the motor 60, and the operation of the rotating tool 18 is crushed. It was easy to be. For this reason, when checking the deflection accuracy of the rotary tool 18, vibration due to such a jerky operation (cogging torque) is transmitted to the dial gauge 29, and accurate measurement is difficult and work efficiency is not good. Therefore, in the present embodiment, in addition to the above-described operation mode, the measurement mode can be executed by the control unit 50 shown in FIG. 8, and in the measurement mode, the rotation speed of the rotation tool 18 is set to the rotation speed of the rotation tool 18 in the operation mode. Slower than speed. Specifically, while the rotating tool 18 is rotated a plurality of times per second in the work mode, the rotating tool 18 is rotated once (rotated approximately 360 °) for a plurality of seconds (for example, approximately 2 to 3 seconds) in the measurement mode. Preferably, the runout accuracy of the rotating tool 18 is confirmed by rotating the motor 60 at a rotational speed of 100 rpm and rotating the rotating tool 18 once in 3 seconds. Thus, by rotating the rotating tool 18 at an ultra-low speed by the motor 60 in the measurement mode, it is possible to accurately check the shake accuracy without being affected by cogging.

  FIG. 8 is a control block diagram of the tabletop cutting machine according to the present embodiment. In FIG. 8, the laser switch 21 and the light switch 22 shown in FIG. 6 are shown together in one block, and the measurement normal rotation switch 23 and the measurement reverse switch 24 shown in FIG. 6 are shown together in one block. Yes.

  A diode bridge 42 is connected to the AC power source 51, and a smoothing capacitor 53 is provided between the output terminals of the diode bridge 42. The voltage supplied from the AC power source 51, full-wave rectified by the diode bridge 42, and smoothed by the smoothing capacitor 53 is applied to the inverter circuit 43. The inverter circuit 43 is a circuit in which switching elements Tr <b> 1 to Tr <b> 6 made of, for example, MOSFETs are connected in a three-phase bridge, and supplies a drive current to the motor 60. The detection resistor Rs converts the current flowing through the motor 60 into a voltage. Switching elements Tr1 to Tr6 correspond to the switching element 76 shown in FIG.

  The operation switch detection circuit 55 transmits a switch operation detection signal according to whether the operation switch 31 is turned on or off to the controller 54. The motor current detection circuit 56 specifies a current flowing through the motor 60 based on the terminal voltage of the detection resistor Rs, and transmits a motor current detection signal to the controller 54. The control signal output circuit (gate driver IC) 57 applies a drive signal such as a PWM signal to the gate of each switching element constituting the inverter circuit 43 under the control of the controller 54.

  The rotor position detection circuit 58 detects the rotation position of the rotor of the motor 60 based on the output signal of the Hall IC 45 provided in the vicinity of the motor 60, and uses the rotor position detection signal as the controller 54 and the motor rotation speed detection circuit. 59. The motor rotation speed detection circuit 59 detects the rotation speed of the motor 60 based on the rotor position detection signal from the rotor position detection circuit 58 and transmits the motor rotation speed detection signal to the controller 54. The controller 54 controls the control signal output circuit 57 according to the switch operation detection signal, the motor current detection signal, the rotor position detection signal, and the motor rotation speed detection signal, and drives each switching element constituting the inverter circuit 43. The motor 60 is rotationally driven. Further, the control unit 50 switches on / off of a laser (not shown) that irradiates the cutting line and the LED 17 in accordance with on / off of the laser switch 21 and the light switch 22.

  When the operation switch 31 is operated, the controller 50 drives the motor 60 in the work mode as described above. When the measurement normal rotation switch 23 or the measurement reverse switch 24 is operated, the motor 60 operates in the measurement mode. Drive. That is, the operation switch 31 is a switch for switching the control unit 50 to the work mode and starting control in the work mode. The measurement forward rotation switch 23 and the measurement reverse rotation switch 24 are switches for switching the control unit 50 to the measurement mode and starting control in the measurement mode.

  In the measurement mode, the control unit 50 rotationally drives the motor 60 at a speed at which the rotating tool 18 rotates once in a plurality of seconds, and stops the motor 60 when the rotating tool 18 makes one rotation (one turn). Note that the difference between the measurement normal rotation switch 23 and the measurement reverse rotation switch 24 is a difference in whether the rotating tool 18 is rotated forward or reverse (FIG. 5) in the measurement mode. When the switch 23 is operated, the motor 60 is controlled to rotate the rotating tool 18 in the forward direction. When the measurement reverse rotation switch 24 is operated, the motor 60 is controlled to rotate the rotating tool 18 in the reverse direction. Note that the control unit 50 stops the motor 60 when the current flowing through the motor 60 becomes equal to or greater than a predetermined value during execution of the measurement mode (when a load greater than the predetermined value is detected).

  In the control unit 50, a work control unit (working microcomputer) for controlling the work mode and a measurement control unit (measuring microcomputer) for controlling the measurement mode may be provided separately from each other. Further, a signal for starting the measurement mode (ON / OFF of the measurement normal rotation switch 23 or the measurement reverse rotation switch 24) may be transmitted to the measurement control unit without going through the work control unit. In this case, it is possible to prevent the work mode from being erroneously started by a signal for starting the measurement mode.

  According to the present embodiment, the following effects can be achieved.

(1) When the control unit 50 detects an operation of the measurement normal rotation switch 23 or the measurement reverse rotation switch 24, the control unit 50 executes the measurement mode and causes the motor 60 to rotate the rotating tool 18 at a super-low speed of one rotation for a plurality of seconds. The user operates the measurement forward rotation switch 23 or the measurement reverse rotation switch 24 with the dial gauge 29 applied to the side surface of the rotation tool 18 so that the swing accuracy of the rotation tool 18 is not affected by cogging. Can be confirmed accurately and efficiently.

(2) In the measurement mode, the control unit 50 automatically stops the motor 60 (rotating tool 18 stops) when the rotating tool 18 is rotated about one turn (about 360 °). Information for confirming the shake accuracy of the rotating tool 18 can be obtained without excess or deficiency by a single operation of the normal rotation switch 23 or the measurement reverse switch 24, and the efficiency of the check operation of the shake accuracy is high.

(3) Since the measurement forward rotation switch 23 and the measurement reverse rotation switch 24 are hidden by the cover 16a and cannot be operated unless the cover 16a is removed, the risk of unexpectedly starting the measurement mode can be suppressed.

(4) When the measurement reversing switch 24 is operated, the rotating tool 18 rotates in the direction opposite to that during the cutting operation. Therefore, it is easy for the user to understand that the measurement mode is set, and the usability is good.

Embodiment 2
FIG. 9 is a cross-sectional view of the main part showing the rotation transmission mechanism of the tabletop cutting machine according to Embodiment 2 of the present invention. The rotation transmission mechanism shown in FIG. 9 includes a drive gear 34 provided on the output shaft 61 of the motor 60, a driven gear 35 that meshes with the drive gear 34, and a one-way clutch 36 provided between the driven gear 35 and the spindle 32. Including. The one-way clutch 36 meshes in the direction in which the driven gear 35 rotates the spindle 32 in the forward direction and transmits the rotational force, and idles in the opposite direction to transmit the rotational force. That is, the one-way clutch 36 does not transmit the rotation of the motor 60 in one direction to the spindle 32 so that the rotating tool 18 can be rotated manually without a load on the motor 60.

  According to the present embodiment, when the rotating tool 18 is rotated by hand, the output shaft 61 of the motor 60 does not rotate even if the rotating tool 18 is rotated in at least one rotation direction. Smooth rotation that is not affected is possible, and the deflection accuracy of the rotating tool 18 can be confirmed accurately and efficiently. In the present embodiment, unlike the first embodiment, the control unit 50 does not have to be able to execute the measurement mode. In this case, the measurement normal rotation switch 23 and the measurement in the first embodiment are not required. The reverse rotation switch 24 is not necessary.

Embodiment 3
FIG. 10 is a cross-sectional view showing a rotation transmission mechanism in the tabletop cutting machine according to Embodiment 3 of the present invention. 11 is an enlarged view of the main part of FIG. 10 in a clutch disengaged state. The rotation transmission mechanism shown in FIG. 10 includes a clutch (electromagnetic clutch) 37, a drive pulley (small pulley) 38, a belt 39, a driven pulley (large pulley) that can be switched between transmission and disconnection by switching whether or not the coil 37a is energized. 40, a drive gear 41a, and a driven gear 41b. The rotation of the output shaft 61 of the motor 60 is transmitted to the drive pulley 38 via the clutch 37. The clutch 37 can rotate integrally with the output shaft 61 and can move in the axial direction of the output shaft 61 by switching between energization and non-energization of the coil 37a. When the clutch 37 moves to the right side of FIG. 11, the clutch 37 and the drive pulley 38 are engaged, and the rotation of the output shaft 61 is transmitted to the drive pulley 38. When the driving pulley 38 rotates, a belt 39 wound between the driving pulley 38 and the driven pulley 40 transmits the rotation of the driving pulley 38 to the driven pulley 40. The rotation of the driven pulley 40 is transmitted to the spindle 32 via the drive gear 41a and the driven gear 41b.

  According to the present embodiment, in the state where the clutch 37 is disengaged, the output shaft 61 of the motor 60 does not rotate even if the rotating tool 18 is manually rotated, so that smooth rotation that is not affected by cogging is possible. The deflection accuracy of the rotary tool 18 can be confirmed accurately and efficiently. In the present embodiment, the measurement forward rotation switch 23 or the measurement reverse rotation switch 24 in the first embodiment uses the clutch disconnection switch for disconnecting the clutch 37 (for switching whether the coil 37a is energized). To allow the user to instruct the controller 50 to disconnect the clutch 37. Also in the present embodiment, as in the second embodiment, the control unit 50 may not be capable of executing a measurement mode in which the motor 60 is rotated at an ultra-low speed.

  The present invention has been described above by taking the embodiment as an example. However, it is understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiment within the scope of the claims. By the way. Hereinafter, modifications will be described.

  In the first embodiment, either the measurement normal rotation switch 23 or the measurement reverse rotation switch 24 may be omitted. In addition, the laser switch 21 or the light switch 22 may be configured to be able to switch to the measurement mode and start the measurement mode by switching in a predetermined pattern, such as continuously switching the laser switch 21 or the light switch 22, for a long time. In this case, both the measurement forward rotation switch 23 and the measurement reverse rotation switch 24 can be omitted.

  In the first embodiment, the motor 60 may be a motor with a brush. If the motor 60 is a motor with a brush, the problem of cogging does not occur, but even in that case, the measurement mode of the first embodiment is executed and the motor 60 rotates the rotating tool 18 once at an extremely low speed. Compared with the case where the rotating tool 18 is rotated by hand, the shake accuracy can be efficiently confirmed.

  The tabletop cutting machine is not limited to the non-slide type described in the embodiment (a type in which the cutting unit 11 does not slide with respect to the holder 5), and even if the cutting unit 11 slides with respect to the holder 5. Good. Moreover, the electric tool to which the present invention is applied is not limited to the tabletop cutting machine exemplified in the embodiment, and other types of electric tools such as a grinder provided with a rotating tool (grinding stone or the like) orthogonal to a rotating shaft (spindle). It may be. In addition to the deflection accuracy of the rotating tool, the measurement can be performed in the same manner for the distortion of the rotating tool.

1 base, 2 turntable, 3 fence, 4 holder shaft (tilting shaft), 5 holder, 10 shaft (oscillating shaft), 11 cutting part (round saw part), 12 spring, 13 discharge port, 15 saw cover (gear cover) , 16 Motor part, 16a Cover, 17 LED, 17a Flexible shaft, 18 Rotating tool, 19 Handle, 21 Laser switch, 22 Light switch, 23 Forward rotation switch for measurement, 24 Reverse rotation switch for measurement, 25 link, 26 Link spindle , 27 Protective cover rotation shaft, 28 Protective cover, 29 Dial gauge, 29a Leg, 30 Clamp lever, 31 Operation switch (trigger switch), 32 Spindle (rotary shaft), 33 Rotation transmission mechanism, 34 Drive gear, 35 Driven Gear, 36 one-way clutch, 37 Latch, 37a Coil, 38 Drive pulley (small pulley), 39 Belt, 40 Driven pulley (large pulley), 41a Drive gear, 41b Driven gear, 42 Diode bridge, 43 Inverter circuit, 45 Hall IC, 50 Controller, 51 AC Power source, 53 smoothing capacitor, 54 controller (microcomputer), 55 operation switch detection circuit, 56 motor current detection circuit, 57 control signal output circuit (gate driver IC), 58 rotor position detection circuit, 59 motor rotation speed detection circuit, 60 Motor, 61 output shaft, 62 rotor core, 63 rotor magnet, 64 stator core, 65 stator coil, 75 switch board, 76 switching element, Rs detection resistor

Claims (10)

A motor,
A rotating shaft rotated by the motor;
A rotating tool attached to the rotating shaft and having a plane perpendicular to the rotating shaft;
A control unit for driving and controlling the motor,
The control unit is capable of executing a work mode for actual work and a measurement mode for measuring the deflection accuracy of the rotating tool,
The electric tool in which the rotation speed of the rotating tool in the measurement mode is lower than the rotating speed of the rotating tool in the work mode. The rotating tool in the working mode rotates a plurality of times per second,
The power tool according to claim 1, wherein the rotating tool in the measurement mode rotates once in a plurality of seconds.   The electric tool according to claim 1 or 2, wherein a rotation direction of the rotary tool in the measurement mode is opposite to a rotation direction of the rotary tool in the work mode.   The said control part is an electric tool as described in any one of Claim 1 to 3 which stops the said motor, if the said rotation tool makes 1 rotation in the said measurement mode.   5. The work operation unit for driving the motor in the work mode and the measurement operation unit for driving the motor in the measurement mode are provided separately from each other. 6. The electric tool according to one item.   The housing further includes a housing for housing the motor, wherein a part of the housing is configured by a cover member that is removable from the housing, and the measurement operation unit is configured to remove the cover member from the housing. The power tool according to claim 5, wherein the power tool is operable.   The power tool according to any one of claims 1 to 6, wherein the control unit stops the motor when a current flowing through the motor becomes a predetermined value or more during execution of the measurement mode.   The electric motor according to any one of claims 1 to 7, wherein the motor is a brushless motor including a stator having a plurality of stator windings and a rotor having a magnetic body rotatable with respect to the stator. tool. A brushless motor comprising a stator having a plurality of stator windings and a rotor having a magnetic body rotatable with respect to the stator;
A rotating shaft rotated by the motor;
A rotating tool attached to the rotating shaft and having a plane perpendicular to the rotating shaft;
A rotation transmission mechanism that transmits the rotation of the rotor to the rotation shaft,
The rotation transmission mechanism may not transmit rotation of the rotating tool in at least one direction to the rotor so that the rotating tool can be rotated without load on the rotor when measuring the deflection accuracy of the plane. ,Electric tool.   The power tool according to claim 9, wherein the rotation transmission mechanism includes a one-way clutch, and the rotor also rotates when the rotating tool is reversely rotated, and the rotor does not rotate when the rotating tool is rotated forward.

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