JP2019047605A - Electrical device - Google Patents

Abstract

To provide an electrical device capable of improving work efficiency.SOLUTION: A short-circuit member 86 provided in an adapter-side terminal portion 85 of an AC power supply adapter 80 short-circuits terminals 15-4 to 15-6 of a terminal portion 15 of an electric power tool 1 as an electric device, and all of six stator coils consisting of U-phase stator coils U1, U2, V-phase stator coils V1, V2, and W-phase stator coils W1, W2 form a Y connection to be energized. On the other hand, a short-circuit member 76 provided in a battery pack adapter 70 short-circuits terminals 15-1 to 15-3, and three stator coils of the U-phase stator coil U1, the V-phase stator coil V1, and W-phase stator coil W1 among the six stator coils form the Y connection to be energized (three stator coils of the U-phase stator coil U2, the V-phase stator coil V2, and the W-phase stator coil W2 are not energized).SELECTED DRAWING: Figure 5

Description

  The present invention relates to an electric device using a brushless motor as a driving source.

  Patent Document 1 below discloses a power tool as an electric device capable of selectively connecting a battery pack and an AC-DC power supply connectable to a commercial AC power supply.

Unexamined-Japanese-Patent No. 2015-82931

  Since the voltage is different between the battery pack and the commercial AC power supply, it is conceivable that the voltage of the commercial AC power supply is adjusted to the voltage of the battery pack by reducing the voltage by duty control in the AC-DC power supply. However, there is a problem that the performance is deteriorated due to the loss in the circuit that drops the voltage, and the working efficiency is poor when the AC-DC power supply is connected to the electric device.

  Also, there are cases where the same electrical equipment is used for both high speed and low torque work and low speed and high torque work, but high speed and low torque are suitable for low speed and high torque motors. In the case of a motor for high speed and low torque, there is a problem that the efficiency of the work suitable for low speed and high torque is deteriorated.

  The present invention has been made in recognition of such a situation, and an object thereof is to provide an electrical device capable of enhancing work efficiency.

One embodiment of the present invention is an electric device provided with a brushless motor,
The brushless motor is
A stator core having a plurality of salient pole parts;
A plurality of stator coils provided in each salient pole portion and present per one phase;
Among the plurality of stator coils, a combination of stator coils to be energized can be switched.

  When the power supply voltage is low, part of the stator coils may be excluded from energization per phase.

  When the power supply voltage is high, all the stator coils may be subjected to energization.

A connection portion capable of selectively connecting a first adapter for connection to the battery pack and a second adapter for connection to an AC power supply,
The combination of stator coils to be energized when the first adapter is connected to the connection portion differs from the combination of stator coils to be energized when the second adapter is connected to the connection portion May be

  When the first adapter is connected to the connection portion, a part of the stator coils may be excluded from energization for one phase.

  When the second adapter is connected to the connection portion, all of the stator coils may be subjected to energization.

The connection portion has a plurality of device side terminals each connected to one end of a predetermined stator coil,
Among the plurality of device side terminals, a plurality of device side terminals connected to each other by the first adapter and a plurality of device side terminals connected to each other by the second adapter are different from each other. The combination of the stator coils may be switched.

  Each of the plurality of device side terminals mutually connected by the first adapter among the plurality of device side terminals is connected between the first and second stator coils belonging to the same phase, and the second adapter Each of the plurality of equipment side terminals connected to each other is one end of a second stator coil located on the opposite side to the voltage input side among the first and second stator coils belonging to the same phase, It may be connected to the other end of one stator coil.

  A manual switch may be provided to switch a combination of stator coils to be energized among the plurality of stator coils.

  When there is a stator coil not to be energized, the stator coil to be energized and the stator coil not to be energized may be alternately arranged in the direction around the axis of the brushless motor.

  A stator coil having a first number of turns and a stator coil having a second number of turns different from the first number of turns may be alternately provided in the direction around the axis of the brushless motor.

Another aspect of the present invention is an electrical apparatus comprising a brushless motor,
The brushless motor is
A stator core having a plurality of salient pole parts;
A plurality of stator coils provided in each salient pole portion and present per one phase;
A stator coil of a first number of turns and a stator coil of a second number of turns different from the first number of turns are alternately provided in the direction around the axis of the brushless motor.

  The brushless motor may have a plurality of phases, and may have stator coils of the first and second numbers of turns in each phase.

Another aspect of the present invention is an electrical apparatus comprising a brushless motor having a plurality of stator coils,
The connection form of the plurality of stator coils can be switched between the Δ connection and the Y connection.

When the power supply voltage is low, the connection form of the plurality of stator coils is Δ connection,
When the power supply voltage is high, the connection form of the plurality of stator coils may be Y-connected.

A connection portion capable of selectively connecting a first adapter for connection to the battery pack and a second adapter for connection to an AC power supply,
When the first adapter is connected to the connection portion, the connection form of the plurality of stator coils becomes Δ connection, and when the second adapter is connected to the connection portion, the connection form of the plurality of stator coils is It may be a Y connection.

  You may provide the manual switch which switches the connection form of these stator coils between delta connection and Y connection.

  It is to be noted that arbitrary combinations of the above-described components, and those obtained by converting the expression of the present invention among methods, systems, and the like are also effective as aspects of the present invention.

  According to the present invention, it is possible to provide an electric device capable of enhancing work efficiency.

FIG. 2 is a side cross-sectional view of the power tool 1 according to Embodiment 1 of the present invention, and is a side cross-sectional view of the power tool 1 in a state of being connected to the battery pack 50 via the battery pack adapter 70. FIG. 10 is a side view of an AC power supply adapter 80 that can be connected to the power tool 1 in place of the battery pack adapter 70. The figure which looked at the motor 3 of the electric tool 1 from the axial direction which abbreviate | omitted the stator coil 3h. The figure which looked at the motor 3 from the axial direction. Description showing wiring connecting the stator coil 3 h of the electric power tool 1 and the tool side terminal portion 15 and showing connection of the tool side terminal portion 15 of the electric power tool 1 and the adapter side terminal portion 85 of the AC power supply adapter 80 Figure. Explanatory drawing which shows the interconnection state of the tool side terminal part 15 of the electric tool 1, and the adapter side terminal part 85 of the adapter 80 for alternating current power supplies. Description showing wiring connecting the stator coil 3h of the electric power tool 1 and the tool side terminal portion 15 and showing connection of the tool side terminal portion 15 of the electric power tool 1 and the adapter side terminal portion 75 of the battery pack adapter 70 Figure. FIG. 10 is an explanatory view showing a state of mutual connection between the tool side terminal portion 15 of the electric power tool 1 and the adapter side terminal portion 75 of the battery pack adapter 70; FIG. 2 is a circuit block diagram of the power tool 1. While showing the wiring which connects the stator coil 3h of the electric tool 1A according to Embodiment 2 of the present invention and the tool side terminal portion 15, the tool side terminal portion 15 of the electric tool 1A and the adapter side of the AC power supply adapter 80A are shown. Explanatory drawing which shows a connection with the terminal part 85. FIG. Explanatory drawing which shows the interconnection state of the tool side terminal part 15 of 1 A of electric tools, and the adapter side terminal part 85 of adapter 80A for alternating current power supplies. Description showing wiring connecting the stator coil 3h of the electric power tool 1A to the tool side terminal portion 15 and connection between the tool side terminal portion 15 of the electric power tool 1A and the adapter side terminal portion 75 of the battery pack adapter 70 Figure. Explanatory drawing which shows the interconnection state of the tool side terminal part 15 of 1 A of electric tools, and the adapter side terminal part 75 of the adapter 70 for battery packs. The top view of the electric tool 1B which concerns on Embodiment 3 of this invention. Explanatory drawing which shows the wiring which connects the stator coil 3h of the electric tool 1B, the manual switch 14, and the power supply cord 13. FIG. Wiring explanatory drawing of the stator coil 3h except the connection change switch 10 in the electric tool which concerns on Embodiment 4 of this invention. Explanatory drawing of the connection form switching of the stator coil 3h by the wire connection changeover switch 10. FIG. The side view of electric tool 1C concerning other embodiments of the present invention.

  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 shown by each drawing, a member, etc., and the overlapping description is abbreviate | omitted suitably. In addition, the embodiments do not limit the invention, and are merely examples, and all the features described in the embodiments and the combination thereof are not necessarily essential to the invention.

Embodiment 1
FIG. 1 is a side sectional view of an electric power tool 1 as an electric device according to a first embodiment of the present invention, and is a side sectional view of the electric power tool 1 connected to a battery pack 50 via a battery pack adapter 70. It is. FIG. 2 is a side view of an AC power supply adapter 80 that can be connected to the power tool 1 in place of the battery pack adapter 70. Referring to FIG. 1, the front, rear, upper and lower directions orthogonal to each other are defined.

  The power tool 1 is a board driver (screw driver). The housing 2 is, for example, a resin molded body, and includes a motor housing portion 2a and a handle portion 2b. The motor housing portion 2a houses the motor 3 therein. The handle portion 2b is a D-type handle, and is connected to the rear end portion of the motor housing portion 2a. The handle portion 2 b is provided with a switch trigger (operation switch) 7 for the user to switch whether or not the motor 3 is energized. The handle portion 2b is also provided with a forward / reverse switching switch 8 for the user to switch between normal rotation and reverse rotation of the motor 3, and an on-lock switch (not shown). The on-lock switch is a switch for the user to switch on / off of the on-lock that locks (locks) the switch trigger 7 to maintain the on state even when the switch trigger 7 is released. The lower end portion of the handle portion 2b is a connection portion 2c, and a tool connection portion 71 of the battery pack adapter 70 as a first adapter shown in FIG. 1 and an AC power supply adapter 80 as a second adapter shown in FIG. The tool connection portion 81 is alternatively detachably connected (slide mounting from the front) by a known latch mechanism.

  In the housing 2, the switching element substrate 30 is provided behind the stator core 3 e of the motor 3, and the main substrate 20 is provided behind the switching element substrate 30. The main substrate 20 and the switching element substrate 30 are both provided substantially perpendicular to the output shaft 3 a of the motor 3. The switching element substrate 30 is provided with six switching elements 31 (corresponding to the switching elements Q1 to Q6 constituting the inverter circuit 42 in FIG. 9) such as FETs or IGBTs. The main substrate 20 is a substrate in which a power supply substrate and a control substrate are combined, and has a function as a power supply substrate and a function as a control substrate.

  The rotation of the motor 3 is transmitted to the tip tool mounting unit 5 via the clutch mechanism 4 as in the prior art (Japanese Patent Laid-Open No. 2009-101501). Hereinafter, the clutch mechanism 4 includes the multi-plate friction clutch 4 a, the one-way clutch 4 b, the spline shaft 4 c, and the clutch drum 4 d. The clutch drum 4 d meshes with the output shaft 3 a of the motor 3 and rotates. One-way clutch 4b is provided between clutch drum 4d and spline shaft 4c, and transmits torque to clutch shaft 4c in the direction in which clutch drum 4d rotates in reverse to spline shaft 4c, while clutch drum 4d is spline shaft 4c. No torque is transmitted in the direction of normal rotation. The spline shaft 4 c is coaxially rotatably fixed to the tip tool mounting portion 5. The multi-plate friction clutch 4a transmits torque from the clutch drum 4d to the spline shaft 4c in a pressed state pressed rearward by the rear end surface of the tip tool mounting portion 5, and does not transmit torque in a non-pressed state. The tip tool mounting unit 5 mounts and holds the bit 6 as a tip tool. A cover 9 that can be attached and removed from the front is attached to the tip tool attachment portion 5. The bit 6 mounted on the tip tool mounting portion 5 slightly protrudes from the front surface (tip surface) of the cover 9. The operations of screwing and unscrewing in the power tool 1 can be performed in the same manner as in a screwing machine of the prior art.

  The motor 3 is an inner rotor type brushless motor here, and is housed in the motor housing portion 2 a of the housing 2. The output shaft 3 a of the motor 3 is rotatably supported relative to the housing 2. As shown in FIGS. 3 and 4, the motor 3 is provided around the output shaft 3 a and has a rotor core 3 b that rotates integrally with the output shaft 3 a, and a plurality of (inserted and held by the rotor core 3 b In the embodiment, four (4) rotor magnets 3c, a stator core 3e provided so as to surround the outer periphery of the rotor core 3b, and a plurality of (six in this embodiment) fixed to the stator core 3e And a child coil 3h. The stator core 3e includes a cylindrical (annular) yoke portion 3f and a plurality of (six in the present embodiment) salient pole portions (tooth portions) 3g projecting radially inward from the yoke portion 3f. A stator coil 3h is provided at each salient pole portion 3g. As shown in FIG. 4, there are six stator coils 3h, U-phase stator coils U1 and U2, V-phase stator coils V1 and V2, and W-phase stator coils W1 and W2. The U-phase stator coil U1, the V-phase stator coil V1, the number of turns of the W-phase stator coil W1 (the first number of turns and 16 turns in this embodiment) are the U-phase stator coil U2, the V-phase stator coil V2, smaller than the number of turns of the W-phase stator coil W2 (the second number of turns, which is 49 turns in the present embodiment). The stator coil 3h is a V-phase stator coil V2, a U-phase stator coil U1, a W-phase stator coil W2, a V-phase stator coil V1, a U-phase stator coil U2, W in the direction around the axis of the motor 3. It is provided in order of the phase stator coil W1 (the stator coil of the first number of turns and the stator coil of the second number of turns are alternately provided).

  The battery pack adapter 70 has a tool connection portion 71, a cable 72, and a battery connection portion 73. The tool connection portion 71 is provided at one end of the cable 72, and the battery connection portion 73 is provided at the other end. The tool connection portion 71 is slide-mounted from the front to the lower end portion (connection portion 2c) of the handle portion 2b of the power tool 1, and is locked by a known latch mechanism. In the mounted state, the tool side terminal portion (apparatus side terminal portion) 15 of the electric power tool 1 and the adapter side terminal portion 75 (provided in the tool connection portion 71) of the battery pack adapter 70 are electrically connected to each other. Ru. The battery connection portion 73 is slide-mounted to the battery pack 50 and locked by a known latch mechanism. In the mounted state, a not-shown battery side terminal portion (provided in battery connection portion 73) of battery pack adapter 70 and a not-shown terminal portion of battery pack 50 are electrically connected to each other.

  As shown in FIG. 2, the AC power supply adapter 80 includes a tool connection 81, a cable 82, and a plug 83. The tool connection portion 81 is provided at one end of the cable 82 and the plug 83 is provided at the other end. The tool connection portion 81 is slide-mounted from the front to the lower end portion (connection portion 2c) of the handle portion 2b of the electric power tool 1 similarly to the tool connection portion 71, and is locked by a known latch mechanism. In the mounted state, the tool side terminal portion 15 of the electric power tool 1 and the adapter side terminal portion 85 (FIG. 5, provided in the tool connection portion 81) of the AC power supply adapter 80 are electrically connected to each other. The plug 83 is connected to an external AC power supply such as a commercial power supply. The effective value of the voltage of the AC power supply is higher than the output voltage of the battery pack 50.

  FIG. 5 shows a wire connecting the stator coil 3 h of the electric power tool 1 and the tool side terminal portion 15, and the tool side terminal portion 15 of the electric power tool 1 and the adapter side terminal portion 85 of the AC power supply adapter 80. It is explanatory drawing which shows a connection. FIG. 6 is an explanatory view showing an interconnection state between the tool side terminal portion 15 of the electric power tool 1 and the adapter side terminal portion 85 of the AC power supply adapter 80. The tool side terminal portion 15 of the electric power tool 1 has terminals 15-1 to 15-8. The interconnection point of U-phase stator coils U1, U2 is connected to terminal 15-1. An interconnection point of the V-phase stator coils V1, V2 is connected to a terminal 15-2. An interconnection point of the W-phase stator coils W1, W2 is connected to a terminal 15-3.

  One end of U-phase stator coil U2 (one end opposite to U-phase stator coil U1) is connected to terminal 15-4. One end (one end opposite to the V-phase stator coil V1) of the V-phase stator coil V2 is connected to the terminal 15-5. One end (one end opposite to the W-phase stator coil W1) of the W-phase stator coil W2 is connected to the terminal 15-6. Two input terminals of the diode bridge 41 as a rectifier circuit are respectively connected to terminals 15-7 and 15-8.

  The U-phase, V-phase and W-phase output terminals of the inverter circuit 42 are one end of U-phase stator coil U1 (one end opposite to U-phase stator coil U2) and one end of V-phase stator coil V1 ( One end opposite to the V-phase stator coil V2 is connected to one end of the W-phase stator coil W1 (one end opposite to the W-phase stator coil W2).

  The adapter-side terminal portion 85 of the AC power supply adapter 80 includes a shorting member 86 and power supply terminals 87 and 88. The power supply terminals 87 and 88 are connected to the terminals 15-7 and 15-8 of the terminal portion 15 of the power tool 1, respectively. The shorting member 86 is made of, for example, a metal piece, and shorts the terminals 15-4 to 15-6 of the terminal portion 15 of the power tool 1. Y-connection (star connection) in which all six stator coils consisting of U-phase stator coils U1 and U2, V-phase stator coils V1 and V2, W-phase stator coils W1 and W2 are energized by the short-circuit member 86 (star connection ) Is made. That is, when the tool connection portion 81 of the AC power supply adapter 80 is connected to the connection portion 2c of the electric power tool 1 (when the power supply voltage is high), all the stator coils 3h are to be energized.

  FIG. 7 shows a wire connecting the stator coil 3 h of the electric power tool 1 and the tool side terminal portion 15, and the tool side terminal portion 15 of the electric power tool 1 and the adapter side terminal portion 75 of the battery pack adapter 70. It is explanatory drawing which shows a connection. FIG. 8 is an explanatory view showing an interconnection state between the tool side terminal portion 15 of the electric power tool 1 and the adapter side terminal portion 75 of the battery pack adapter 70. Although illustration is abbreviate | omitted in FIG.7 and FIG.8, you may provide the terminal and path | route (LD terminal and LD signal line) for transmitting an abnormality detection signal from the battery pack 50 to the electric tool 1. FIG.

  The adapter-side terminal portion 75 of the battery pack adapter 70 has a shorting member 76 and power terminals 77, 78. The power supply terminals 77 and 78 are connected to the terminals 15-7 and 15-8 of the terminal portion 15 of the power tool 1, respectively. The shorting member 76 is made of, for example, a metal piece, and shorts the terminals 15-1 to 15-3 of the terminal portion 15 of the power tool 1. The short circuit member 76 causes the three stator coils of the U-phase stator coil U1, the V-phase stator coil V1 and the W-phase stator coil W1 among the six stator coils to be energized and the U-phase stator A Y connection (star connection) is formed in which the three stator coils of the coil U2, the V-phase stator coil V2 and the W-phase stator coil W2 are not subjected to energization. That is, when the tool connection portion 71 of the battery pack adapter 70 is connected to the connection portion 2c of the electric power tool 1 (when the power supply voltage is low), a part of the stator coils 3h in each phase is not subject to energization. Become. Here, as shown in FIG. 4, a stator coil (U-phase stator coil U1, V-phase stator coil V1, W-phase stator coil W1) to be energized and a stator coil (U) not to be energized Phase stator coils U2, V-phase stator coils V2, W-phase stator coils W2) are alternately arranged in the direction around the axis of the motor 3.

  FIG. 9 is a circuit block diagram of the power tool 1. The inverter circuit 42 includes six switching elements Q1 to Q6 such as FETs and IGBTs connected in a three-phase bridge. The resistor Rs is provided in the path of the drive current of the motor 3. Three magnetic sensors 43 such as Hall ICs are provided in the vicinity of the motor 3 and output signals according to the rotational position (rotor position) of the motor 3. In the control circuit unit 40, the motor current detection circuit 44 detects the current flowing through the motor 3 based on the voltage at both ends of the resistor Rs, and transmits the current to the calculation unit 50. The voltage detection circuit 45 detects the voltage between the output terminals of the diode bridge 41 and transmits the voltage to the calculation unit 50. The switch operation detection circuit 46 detects an operation (on / off) of the switch trigger 7 and transmits the operation to the arithmetic unit 50. The control signal output circuit 47 applies a drive signal (for example, a PWM signal) to each control terminal (each gate) of the switching elements Q1 to Q6 according to the control of the arithmetic unit 50. The rotor position detection circuit 48 detects the rotational position of the motor 3 based on the output signal of the magnetic sensor 43, and transmits it to the calculation unit 50. The motor rotation number detection circuit 49 detects the rotation number of the motor 3 based on the output signal of the rotor position detection circuit 48, and transmits the rotation number to the calculation unit 50. Arithmetic unit 50 controls (for example, PWM control) switching elements Q1 to Q6 of inverter circuit 42 via control signal output circuit 47, and rotationally drives motor 3.

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

(1) When the tool connection portion 81 of the AC power supply adapter 80 is connected to the connection portion 2 c of the electric power tool 1 (when the power supply voltage is high), all the stator coils 3 h are targeted for energization. When the tool connection portion 71 of the battery pack adapter 70 is connected to the connection portion 2c (when the power supply voltage is low), the power supply voltage is high because a part of the stator coils 3h is excluded from energization in each phase. In this case, the effective number of turns of the stator coil 3h increases, and when the power supply voltage is low, the effective number of turns of the stator coil 3h decreases. That is, the effective number of turns can be set according to the power supply voltage, for example, the loss due to the circuit can be reduced compared to the case where the voltage of the AC power supply is dropped according to the voltage of the battery pack 50, and the working efficiency is increased. It can be enhanced.

(2) The switching of the combination of the stator coils 3h to be energized is performed by connecting the tool connecting portion 71 of the battery pack adapter 70 or the tool connecting portion 81 of the AC power supply adapter 80, so Accordingly, the user does not have to perform the switching operation, which is convenient.

(3) Stator coils (U-phase stator coil U1, V-phase stator coil V1, W-phase stator) to be energized when there is a stator coil 3h to be deenergized (when the power supply voltage is low) Because the coil W1) and the stator coils (U-phase stator coil U2, V-phase stator coil V2, W-phase stator coil W2) not to be energized are alternately arranged in the direction around the axis of the motor 3. Uneven rotation of the motor 3 can be suppressed. Further, since the heat generation of the stator coil 3h in the case where there is the stator coil 3h which is not targeted for energization is dispersed at equal intervals around the axis of the motor 3, high temperature abnormality of the motor 3 can be suppressed.

Second Embodiment
FIG. 10 shows a wire connecting the stator coil 3h of the electric power tool 1A as the electric device according to the second embodiment of the present invention and the tool side terminal portion 15, and the tool side terminal portion 15 of the electric power tool 1A It is explanatory drawing which shows the connection with the adapter side terminal part 85 of adapter 80A for alternating current power supplies. FIG. 11 is an explanatory view showing an interconnection state between the tool side terminal portion 15 of the electric power tool 1A and the adapter side terminal portion 85 of the AC power supply adapter 80A. FIG. 12 shows a wire connecting the stator coil 3h of the electric power tool 1A and the tool side terminal portion 15, and the tool side terminal portion 15 of the electric power tool 1A and the adapter side terminal portion 75 of the battery pack adapter 70. It is explanatory drawing which shows a connection. FIG. 13 is an explanatory view showing an interconnection state between the tool side terminal portion 15 of the electric power tool 1A and the adapter side terminal portion 75 of the battery pack adapter 70. As shown in FIG. The electric power tool 1A of the present embodiment is different from the electric power tool 1 of the first embodiment in that the diode bridge 41 is not provided, and the other points coincide. Further, the AC power supply adapter 80A of the present embodiment is different from the AC power supply adapter 80 of the first embodiment in that the diode bridge 89 is included, and the other points are the same. According to the present embodiment, the size of the AC power supply adapter 80A is larger than that of the AC power supply adapter 80 of the first embodiment by the portion having the diode bridge 89, while the power tool 1A has the diode bridge 41. The size can be reduced by the amount not to be, and since the current of the battery pack 50 does not pass through the diode bridge when the battery pack adapter 70 is connected, the loss due to the diode bridge when the rectification is unnecessary can be eliminated.

Third Embodiment
FIG. 14 is a plan view of a power tool 1B as an electric device according to Embodiment 3 of the present invention. FIG. 15 is an explanatory view showing wiring for connecting the stator coil 3 h of the electric power tool 1 B to the manual switch 14 and the power supply cord 13. The electric power tool 1B is a known portable cutting machine (mobile circular saw) except that the combination of the stator coils 3h to be energized can be switched by the manual switch 14. The manual switch (winding switching switch) 14 is provided on a portion of the housing 2 which is shifted to the left side with respect to the grip portion 2 e when viewed from above and which faces the upper portion.

  As shown in FIG. 15, when the manual switch 14 is set to the high speed / low torque side, the terminals 15-1 to 15-3 of the electric power tool 1B are shorted by the manual switch 14, and one of the six stator coils Three stator coils of U-phase stator coil U1, V-phase stator coil V1 and W-phase stator coil W1 are to be energized, and U-phase stator coil U2, V-phase stator coil V2, W-phase fixed A Y connection (star connection) is formed in which the three stator coils of the child coil W2 are not subjected to energization. On the other hand, when the manual switch 14 is set to the low speed / high torque side, the terminals 15-4 to 15-6 of the electric power tool 1B are short-circuited by the manual switch 14, U phase stator coils U1, U2, V phase stator Y connection (star connection) in which all of the six stator coils including the coils V1 and V2 and the W phase stator coils W1 and W2 are to be energized is formed.

  According to the present embodiment, when the manual switch 14 is set to the low speed / high torque side, all the stator coils 3h are energized and the effective number of turns of the stator coil 3h increases, and the manual switch 14 is high speed / low If it is set on the torque side, part of the stator coil 3h will not be energized and the effective number of turns of the stator coil 3h will decrease, so the nature of the work you want to do (a low speed high torque work or high speed low It is possible to achieve an appropriate number of turns according to whether the torque is a suitable work) and to improve the work efficiency. The manual switch 14 may be provided on the rear side surface of the grip portion 2e as in the case of the electric power tool 1C shown in FIG.

Embodiment 4
FIG. 16 is a wiring diagram of the stator coil 3 h excluding the wire connection switching switch 10 in the electric power tool as the electric device according to Embodiment 4 of the present invention. FIGS. 17A and 17B are explanatory diagrams of connection mode switching of the stator coil 3 h by the connection changeover switch 10. In the present embodiment, the six stator coils 3h all have the same number of turns. The wire connection switching switch 10 is a manual switch (3-pole switch) that switches the connection form of the six stator coils 3h between the Δ connection and the Y connection, and is provided, for example, in the same manner as the manual switch 14 of FIG. As shown in FIG. 17A, when the wire connection switch 10 is set to the high speed and low torque side, the terminals a1 and b1, the terminals a2 and b2, and the terminals a3 and b3 are short-circuited, respectively, and six stators are formed. The connection form of the coil 3 h is Δ connection. On the other hand, as shown in FIG. 17B, when the wire connection switch 10 is set to the low speed and high torque side, the terminals a1 and c1, the terminals a2 and c2, and the terminals a3 and c3 are short-circuited, respectively. The connection form of the stator coil 3h is Y connection (star connection). The Δ connection and the Y connection have a relationship such that the rotation number of the Δ connection is √3 times (about 1.7 times) that of the Y connection under the same number of turns and the same drive condition. That is, the connection switching switch 10 can be made into a suitable stator coil 3 h connection form that matches the nature of the work to be performed (whether low speed, high torque is suitable work or high speed, low torque is suitable work). The work efficiency can be improved. In addition, even when the wire connection switch 10 is set to either high speed / low torque side or low speed / high torque side, all the stator coils 3 h are to be energized, so some of the stator coils 3 h are not to be energized. Since the heat generation of the stator coil 3 h is dispersed as compared with the case of the above, the high temperature abnormality of the motor 3 can be suppressed. The wire connection changeover switch 10 may be provided on the rear side surface of the grip portion 2e as in the case of the electric power tool 1C shown in FIG.

  Although the present invention has been described above by taking the embodiment as an example, 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. It is a place. The following describes the modification.

  In Embodiments 1 to 3, as an example of switching of the combination of stator coils 3h to be energized, the case where all six stator coils are to be energized, U-phase stator coil U1, V-phase fixation When three stator coils of child coil V1 and W phase stator coil W1 are to be energized (three stator coils of U phase stator coil U2, V phase stator coil V2 and W phase stator coil W2 are In the case where switching between the case of being excluded from energization and the case described above was performed, but three stator coils of U-phase stator coil U2, V-phase stator coil V2 and W-phase stator coil W2 are to be energized (U (When the three stator coils of the phase stator coil U1, V-phase stator coil V1 and W-phase stator coil W1 are not to be energized), U-phase stator coil U1, V-phase stator coil V1, W Solid phase stator coil W1 In the case where the child coils are to be energized (when the three stator coils of the U-phase stator coil U2, the V-phase stator coil V2 and the W-phase stator coil W2 are not subjected to energization), It is also good.

  In the fourth embodiment, an example has been described in which the user switches the connection form of the stator coil 3h between the Δ connection and the Y connection by the operation of the connection changeover switch 10. However, for example, as shown in FIG. The battery pack adapter 70 is connected in a Δ connection when the 70 is connected (when the power supply voltage is low) and is a Y connection when the AC power supply adapter 80 shown in FIG. 2 is connected (when the power supply voltage is high). The connection destination of the connection changeover switch 10 may be switched by connecting the tool connection portion 71 of the above or the tool connection portion 81 of the AC power supply adapter 80.

DESCRIPTION OF SYMBOLS 1 electric tool, 2 housing, 2a motor accommodation part, 2b handle part, 2c connection part, 3 motor, 3a output shaft, 3b rotor core, 3c rotor magnet, 3e stator core, 3h stator coil, 3f yoke part , 3g salient pole part (teeth part), 4 clutch mechanism, 4a multiple disc friction clutch, 4b one way clutch, 4c spline shaft, 4d clutch drum, 5 tip tool mounting part, 6 bit (tip tool), 7 trigger switch (operation Switch), 8 forward / reverse switch, 9 cover, 10 wire connection switch, 13 power cord, 14 manual switch (winding switch), 15 tool side terminal (equipment side terminal), 20 main board, 30 switching element Substrate (IGBT substrate), Adapter for 70 battery pack (first adapter), DESCRIPTION OF SYMBOLS 1 Tool connection portion, 72 cable, 73 battery connection portion, 75 adapter side terminal portion (first terminal portion), 80 AC power supply adapter (second adapter) 81 tool connection portion, 82 cable, 83 plug, 85 adapter side Terminal (second terminal),

Claims (17)

An electrical device comprising a brushless motor,
The brushless motor is
A stator core having a plurality of salient pole parts;
A plurality of stator coils provided in each salient pole portion and present per one phase;
An electric device capable of switching a combination of stator coils to be energized among the plurality of stator coils.   The electric device according to claim 1, wherein when the power supply voltage is low, a part of the stator coils per one phase is excluded from energization.   The electric device according to claim 2, wherein all the stator coils are to be energized when the power supply voltage is high. A connection portion capable of selectively connecting a first adapter for connection to the battery pack and a second adapter for connection to an AC power supply,
The combination of stator coils to be energized when the first adapter is connected to the connection portion differs from the combination of stator coils to be energized when the second adapter is connected to the connection portion The electric device according to claim 1.   The electric device according to claim 4, wherein when the first adapter is connected to the connection portion, a part of stator coils per one phase is excluded from energization.   The electric device according to claim 5, wherein when the second adapter is connected to the connection portion, all the stator coils are to be energized. The connection portion has a plurality of device side terminals each connected to one end of a predetermined stator coil,
Among the plurality of device side terminals, a plurality of device side terminals connected to each other by the first adapter and a plurality of device side terminals connected to each other by the second adapter are different from each other. The electric device according to any one of claims 4 to 6, wherein a combination of stator coils is switched.   Each of the plurality of device side terminals mutually connected by the first adapter among the plurality of device side terminals is connected between the first and second stator coils belonging to the same phase, and the second adapter Each of the plurality of equipment side terminals connected to each other is one end of a second stator coil located on the opposite side to the voltage input side among the first and second stator coils belonging to the same phase, The electric device according to claim 7, which is connected to an opposite end of one stator coil.   The electric device according to claim 1, further comprising a manual switch that switches a combination of stator coils to be energized among the plurality of stator coils.   10. The stator coil according to any one of claims 1 to 9, wherein the stator coil to be energized and the stator coil not to be energized are alternately arranged in the direction around the axis of the brushless motor when there is a stator coil not to be energized. Electrical apparatus according to any one of the items.   The stator coil of the first number of turns and the stator coil of the second number of turns different from the first number of turns are alternately provided in the direction around the axis of the brushless motor. The electric device as described in a paragraph. An electrical device comprising a brushless motor,
The brushless motor is
A stator core having a plurality of salient pole parts;
A plurality of stator coils provided in each salient pole portion and present per one phase;
An electric device, wherein a stator coil having a first number of turns and a stator coil having a second number of turns different from the first number of turns are alternately provided in the direction around the axis of the brushless motor.   The electric device according to claim 11, wherein the brushless motor has a plurality of phases, and has stator coils of the first and second numbers of turns in each phase. An electric apparatus comprising a brushless motor having a plurality of stator coils, the electric apparatus comprising:
An electrical device, wherein a connection form of the plurality of stator coils is switchable between a Δ connection and a Y connection. When the power supply voltage is low, the connection form of the plurality of stator coils is Δ connection,
The electric device according to claim 14, wherein when the power supply voltage is high, a connection form of the plurality of stator coils is Y connection. A connection portion capable of selectively connecting a first adapter for connection to the battery pack and a second adapter for connection to an AC power supply,
When the first adapter is connected to the connection portion, the connection form of the plurality of stator coils becomes Δ connection, and when the second adapter is connected to the connection portion, the connection form of the plurality of stator coils is The electric device according to claim 14, which is a Y-connection.   The electric device according to claim 14, further comprising a manual switch that switches a connection form of the plurality of stator coils between a Δ connection and a Y connection.