TWI712251B - Electric motors and electric tools - Google Patents

Abstract

The invention relates to an electric motor and an electric tool equipped with the electric motor. The electric motor includes a rotor, a stator, a coil module wound around the stator, a Hall unit, and a wiring circuit unit. The Hall unit includes a Hall circuit board arranged around the rotating shaft of the rotor, and a Hall module for sensing the rotation of the rotor. The wiring circuit unit is independent of the Hall circuit board and includes a three-phase power interface. The wiring circuit unit electrically connects the coil groups of the coil module to the power interfaces. By disassembling the Hall unit and the connection circuit unit and setting them independently, the volume of the Hall circuit board can be reduced, and the area of the air flow path blocked in the heat dissipation unit can be reduced, so the electric motor and power tool can be improved heat radiation.

Description

Electric motors and electric tools

The present invention relates to components of electric transmission, and in detail refers to an electric motor and an electric tool with such an electric motor.

Electric tools such as electric impact wrenches, electric drills, electric screwdrivers, etc., are all very commonly used decoration tools. Refer to Figure 1 and Figure 2. The basic structure of a conventional electric tool includes an electric motor 11, a fan 12, and a Corresponding to the circuit board 13 provided with the electric motor 11, three Hall elements 14, and a wiring module 15 with a three-phase power interface 151.

The electric motor 11 has a rotor 111, a stator 112 surrounding the rotor 111, and a plurality of coils (not shown) wound around the stator 112.

The circuit board 13 is provided for the Hall elements 14 and a wiring module 15. The Hall elements 14 are arranged at the inner circle of the circuit board 13 and used to sense the rotation of the rotor 111. The wiring module 15 is provided The coils are electrically connected to the outer ring of the circuit board 13 to set the electrical connection relationship of the coils so that the coils are grouped and electrically connected to the three-phase power interface 151.

However, since the outer diameter of the circuit board 13 needs to be large enough for the wiring module 15 to electrically connect the coils drawn from the stator 112, its inner diameter needs to be small enough for the Hall elements 14 to be close to sense. It is measured that the rotor 111 rotates. Therefore, the distance from the inner diameter to the outer diameter is long, and the volume is large. The Hall elements 14 need to be close to the rotor 111 to obtain a better sensing effect, and the position is just blocked. The air flow path provided by the fan 12 makes the electric motor 11 poorly ventilated on the side close to the circuit board 13, resulting in poor heat dissipation effect of the electric motor 11.

In addition, in addition to software control, the structure of the conventional electric motor cannot adjust the speed.

Therefore, the object of the present invention is to provide an electric motor and electric tool that can improve the heat dissipation effect.

Another object of the present invention is to provide an electric motor and an electric tool, which can adjust the rotation speed of the electric motor without replacing hardware equipment.

The electric motor provided by the present invention includes: A rotor with a rotating shaft; A stator, surrounding the rotor; A coil module with a plurality of coils wound around the stator; A Hall unit, including a Hall circuit board arranged around the rotating shaft, and a pair of Hall modules arranged on the Hall circuit board corresponding to the rotor and used for sensing the rotation of the rotor; and A wiring circuit unit is independent of the Hall circuit board and includes a three-phase power interface. The wiring circuit unit is electrically connected to the coils and the coils are grouped and electrically connected to the power interfaces.

The electric tool provided by the present invention includes a housing unit, a battery unit, the aforementioned electric motor, a heat dissipation unit, and a control unit; The battery unit is arranged on the lower side of the housing unit; The electric motor is installed in the housing unit; the Hall unit and the heat dissipation unit are spaced apart in the longitudinal direction of the rotating shaft; The control unit is arranged in the housing unit, is electrically connected to the battery unit, the electric motor and the Hall unit, and is located between the electric motor and the battery unit.

The effect of the present invention is that by disassembling the Hall unit and the connection circuit unit and separately setting them, the volume of the Hall circuit board can be reduced, and the area blocked on the air flow path provided by the heat dissipation unit can be reduced. The heat dissipation effect of the electric motor and electric tool can be improved.

And another feature of the structural design of the present invention is that when assembling the electric motor, the setting angle of the Hall circuit board can be changed, and the rotation speed of the motor can be adjusted without replacing any parts or hardware equipment.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are represented by the same numbers.

4, 5 and 7, the first preferred embodiment of the electric tool of the present invention includes a housing unit 2, an electric motor 3, a Hall unit 4, a wiring circuit unit 5, a control unit 6, A battery unit 7, a heat dissipation unit 8, and a tool head 201 arranged on the housing unit 2 and driven by the electric motor 3, as shown in FIG. 15, make the tool head generate a rotation output to rotate the workpiece. Among them, the tool head is not a technical feature of this case, so I won't explain it here.

3, 4, and 5, the housing unit 2 includes a first housing 21, a first housing 21 that matches with the first housing 21 and defines a space 24 for the electric motor 3, the Hall unit 4, and the connection The second housing 22 provided for the circuit unit 5 and a bracket 23 provided in the first housing 21 and the second housing 22 for the Hall unit 4 to be provided.

The first housing 21 and the second housing 22 respectively have bracket slots 211 and 221 for clamping two ends of the bracket 23.

The bracket 23 has a ring-shaped body portion 231 for the Hall circuit board 41 of the Hall unit 4, and two body portions 231 that extend outward from the body portion 231 and are respectively clamped on the first housing 21 and the second housing 21. The bracket portions 232 of the bracket grooves 211 and 221 of the casing 22. The main body 231 has a plurality of fasteners 233. Wherein, the bracket 23 can also include three, four, or five or more bracket portions 232 according to actual needs, and is not limited to this.

4, 5 and 6, the electric motor 3 includes a rotor 31 having a rotating shaft 311, a stator 32 surrounding the rotor 31, and a coil module 33 having a plurality of coils 332 wound around the stator 32 .

The Hall unit 4 and the heat dissipation unit 8 are arranged at intervals along the longitudinal direction of the rotating shaft 311, and include a Hall circuit board 41 surrounding the rotating shaft 311 and disposed on the housing unit 2, and a corresponding rotor 31 and disposed on the Hall circuit board. The circuit board 41 is used for sensing the rotation of the rotor 31 and the Hall module 42. The Hall circuit board 41 has a plurality of buckle grooves 411 for buckling the buckles 233 respectively. The Hall module 42 has three Hall elements 421 disposed adjacent to the rotor 31.

The connecting circuit unit 5 includes a connecting circuit board 51 independent of the Hall circuit board 41 and surrounding the rotating shaft 311, a connecting circuit 52 arranged on the connecting circuit board 51, and a three connecting circuit board arranged on the connecting circuit board 51. The connection circuit 52 is electrically connected to the coils 332 of the coil module 33 and the coils 332 are electrically connected to the power interfaces 53 in groups. The power interfaces 53 are used to receive three-phase power enter. In this embodiment, the connecting circuit board 51 is ring-shaped and is arranged around the Hall circuit board 41 with a gap 54. However, the connecting circuit board 51 and the Hall circuit board 41 may also be along the rotation axis 311 Longitudinal spacing setting, this will increase the length and volume of the electric motor, but it can get better ventilation and heat dissipation.

Referring to Figures 5, 6 and 7, the control unit 6 is arranged in the housing unit 2, at the grip portion 20 formed by the housing unit, and is electrically connected to the electric motor 3, the Hall unit 4 and the The battery unit 7 is located between the electric motor 3 and the battery unit 7. The control unit 6 has a circuit unit, including a printed circuit board (PCB), a plurality of power switch elements (not shown), and a touch switch (not shown). The aforementioned Hall circuit board 41 and the connection circuit board 51 are also electrically connected to the circuit unit of the control unit 6. The circuit unit of the control unit 6 includes a drive loop (first loop circuit) and a control loop (second loop circuit) for setting the power switch elements. The power switching element can be a MOSFET transistor (metal oxide semiconductor field effect transistor) or an IGBT transistor (insulated gate bipolar transistor), which is arranged on the printed circuit board of the control unit 6. The power switch element in the drive loop controls the action of the electric motor 3; the control loop controls the ON/OFF of the power switch element in the drive loop. Thereby, the control unit 6 will switch the power switch elements ON/OFF (on/off) according to the signal detected by the Hall module 42 to control the operation of the electric motor 3.

The battery unit 7 is arranged on the lower side of the housing unit 2, preferably under the grip of the user, and is used to provide power. The battery unit 7 supplies power to the control circuit and drive circuit of the control unit 6, and other electronic components that require power, such as LED lights, liquid crystal screens, and so on. Press the tact switch to start or stop the electric tool.

The heat dissipation unit 8 corresponds to the electric motor 3 and is arranged inside the housing unit 2, and is arranged on the side of the electric motor 3 opposite to the Hall unit 4 and the connection circuit unit 5 to provide the electric motor 3 Air flow for heat dissipation. Among them, the heat dissipation unit 8 is preferably a fan.

4, 5, and 6, through the above description, the advantages of this embodiment can be summarized as follows:

1. By disassembling the Hall unit 4 and the connecting circuit unit 5 and setting them independently, the volume of the Hall circuit board 41 can be reduced, and the area blocked on the air flow path provided by the heat dissipation unit 8 can be reduced. The heat dissipation effect of the electric motor 3 is improved.

Furthermore, by disposing the connecting circuit 52 on the connecting circuit board 51 that is independent of the Hall circuit board 41, both the Hall circuit board 41 and the connecting circuit board 51 can be made into smaller circuits. The plate, as can be seen in Figure 6, even if the two 41, 51 are arranged on the same side (front side) of the electric motor and arranged in the inner and outer rings in order to reduce the longitudinal length and volume of the electric motor, the space between the two is still The gap 54 (a gap formed between the inner periphery of the wiring circuit board and the outer periphery of the Hall circuit board) can be used for air flow to circulate, and it has a better heat dissipation effect than the conventional technology.

Refer to Figures 8, 9 and 10, which are the second preferred embodiment of the electric tool of the present invention. This embodiment is similar to the first embodiment, and the difference from the first embodiment is: the housing unit 2 It includes a matching first motor cover and a second motor cover, such as a motor front cover 25 and a motor rear cover 26. A motor space 28 is defined between the two 25 and 26 for the electric motor 3 and The Hall unit 4 is provided, and the Hall circuit board 41 is installed on one of the two motor covers. In this embodiment, a plurality of positioning members 27 are used to pass through the Hall circuit board 41, and the Hall circuit board 41 is assembled to the motor back cover 26. Each positioning member 27 is preferably a screw, which can be loosened, tightened, and Disassemble.

Referring to FIGS. 9, 11 and 12, the stator 32 has a cylindrical yoke 321 and a hexapole 322, which are annularly arranged on the inner peripheral surface of the yoke 321 at appropriate angles (for example, at equal intervals). And a bobbin part 323 disposed at one end of the yoke part 321 along the longitudinal direction of the yoke part 321. For clarity of description, the pole portions 322 are respectively marked as 322a to 322f in a winding direction X in FIG. 12.

The coil module 33 has six coils 332 respectively wound around the pole portions 322, a surrounding portion 333 connected to the coils 332 and wound on the bobbin portion 323, and three coils 332 extending from the surrounding portion 333 And respectively serve as the connection parts 334 of the power interfaces 53. For clarity of description, the coils 332 are respectively marked as 332a to 332f in FIG. 12 according to the winding direction X, and the connecting portions 334 are respectively marked as 334a to 334c according to the winding direction X in FIG. 12. Wherein, when the electric motor 3 is not yet assembled, the coil module 33 also has two free ends 335, and the two free ends 335 will be Cut off the motor 3 after assembly.

In this embodiment, the number of the pole portions 322 and the coils 332 is six, but those skilled in the art can also change the number to 12, 24, 36, etc. for general three-phase horses according to actual needs. The number of common poles is not limited to this.

The Hall circuit board 41 is disposed on the motor back cover 26 corresponding to the rotor 31 and has a plurality of through holes 412 for the positioning members 27 to pass through.

The wiring circuit unit 5 further includes a short-circuit piece 55 disposed on the winding frame portion 323, and the short-circuit piece 55 is clamped on the surrounding portion 333 to electrically connect the coils 332. The short-circuit piece 55 preferably has a setting portion 521 disposed on the bobbin portion 323, and two clamping portions 522 extending from the setting portion 521 and used to clamp the surrounding portion 333. The short-circuit piece 55 is more Preferably, the surrounding portion 333 is electrically connected by spot welding or crimping contact, so that the coils 332 are electrically connected.

The coils 332 of the electric motor 3 are made by a conductive wire winding method. The wire winding method starts from the free end 335 on the right side in FIG. 12, and starts from the short circuit along the winding direction X. The position of the sheet 55 enters, and then it is wound around the pole portion 322a, forming the wiring portion 334a, wound on the pole portion 322d, and then passed through the short-circuit sheet 55, wound on the pole portion 322b, forming the wiring portion 334b , Wound on the pole portion 322e, and then through the short-circuit piece 55, wound on the pole portion 322c, forming the terminal portion 334c, wound on the pole portion 322f, passing the short-circuit piece 55, and finally form the left side of Figure 12 The free end 335. In detail, based on the X direction, the wire is first wound around the first pole portion 322a and the fourth pole portion 322d to form the first wiring portion 334a, and then wound around the second pole portion 322b and the first pole portion 322d. The pentapole portion 322e and the second wiring portion 334b are formed, and finally wound around the third pole portion 322c and the sixth pole portion 322f to form the third wiring portion 334c. Wherein, for clarity of description, in FIG. 11, the surrounding portion 333 of the wire is wound four times through the short-circuit piece 55, and the surrounding portion 333 forms four contacts on the short-circuit piece 55, which are respectively labeled according to the winding sequence It is 333a~333d.

After completing the winding of the coil module 33, the clamping portions 522 of the short-circuit sheet 55 upwardly press the surrounding portion 333, and the four contacts 333a~333d on the surrounding portion 333 are all spot welded In this way, the coil module 33 can be formed into a Y-shaped connection type as shown in FIG. 13, wherein the short-circuit strip 55 is the central connection point O of the Y-shaped connection.

Referring to FIGS. 9, 10, and 11, in this second preferred embodiment, apart from disassembling the Hall unit 4 and the connection circuit unit 5 and setting them independently, it can reduce the cost of the Hall circuit board 41. In addition to reducing the volume and reducing the area blocked on the air flow path provided by the heat dissipation unit 8, thereby improving the heat dissipation effect of the electric motor 3, the short-circuit sheet 55 can also be electrically connected to the coils 332 by the above-mentioned winding method. And the connection parts 334 are used as the three-phase power interface 53 of the motor, and the arrangement of the connection circuit board 51 (see FIG. 4) in the first preferred embodiment can be omitted, so that the heat dissipation unit 8 Only the Hall circuit board 41 is left in the air duct, so the air volume that can be circulated can be greatly increased, and a better heat dissipation effect can be obtained.

Referring to FIG. 8, the motor rear cover 26 is provided with three conductive sheets 261, which are respectively electrically connected to the three wiring portions 334 (53), so that the electric motor is installed in the front and rear covers 25, 26 to facilitate the penetration of the three conductive sheets 216 Connect the line. In addition, the rear cover 26 is provided with an opening 262 for exposing the short circuit piece 55, the clamping portion 522 and the surrounding portion 333.

Refer to FIG. 14, which is another implementation aspect of the Hall circuit board 41. In this aspect, the extension length of each through hole 412 around the rotating shaft 311 is greater than the radial width of the corresponding positioning member 27, thereby , The installation angle of the Hall circuit board 41 can be fine-tuned clockwise or counterclockwise during assembly, that is, the angular position of the Hall circuit board relative to the yoke of the stator can be adjusted, so that the electric motor 3 can be changed. The switching angle of the electric motor 3 changes the rotation speed of the electric motor 3, and the adjustment range of the rotation speed is about 5~10%. In this way, it is possible to adjust the Hall circuit board without changing any hardware equipment. The setting angle of 41 achieves the effect of fine-tuning the speed. In practical applications, the best angle of each series of products can be obtained through experiments, and then assembled at the best angle to obtain the effect that can be optimized for each series of products.

Please refer to FIG. 15, which is a third preferred embodiment of the electric tool of the present invention. This embodiment can be the structure shown in the first or second preferred embodiment, and the circuit unit of the control unit 6 is further disassembled It is divided into a first loop unit and a second loop unit electrically connected. The first loop unit includes a first circuit board 61, which is a MOS circuit board, on one side of which is provided with the aforementioned drive circuit (first loop circuit) , And a number of power switching elements, which are MOSFET transistors or IGBT transistors (not shown), are installed in the driving circuit of the first circuit board 61. The second loop unit includes a second circuit board 64, which is a control board, and is provided with the aforementioned control loop (second loop circuit). The touch switch 65 of the control unit 6 is provided at the handle portion 20, and It is electrically connected with the control circuit, and the electric tool is started or stopped by pressing or releasing the tact switch 65. In this embodiment, the first circuit board 61 and the second circuit board 64 are respectively arranged on the upper side and the lower side of the tact switch 65 to maintain a gap.

In addition, since the power switch element generates heat, a heat dissipation plate 62, such as a heat dissipation fin, is adhered to one surface of the first circuit board 61 with thermally conductive silicon glue. The heat sink 62 and the thermally conductive silicon glue help the first circuit board 61 to dissipate heat. .

Fig. 16 is a fourth preferred embodiment of the electric tool of the present invention. This embodiment is basically the same as the third embodiment, and the same components are used with the same reference numerals, and no further description is needed. In this embodiment, the control unit 6 is also set up as an independent first circuit board 61 (with the drive circuit) and a second circuit board 64 (with the control circuit) that are spaced apart. The two circuit boards 61 and 64 are located on the The handle portion 20 of the housing unit 2. More specifically, the two circuit boards are juxtaposed between the tact switch 65 and the battery unit 7.

The third and fourth embodiments described above separate the MOS board (i.e., the first circuit board) and the control board (i.e., the second circuit board). On the one hand, it can more effectively dissipate the power switch components, and on the other hand, it can make the control board The electronic components are far away from the power switch components to avoid the thermal influence of the power switch components to ensure the normal operation and long service life of the electronic components of the control board.

Furthermore, since the control unit is made into the first and second circuit boards, the heat sink 62 only needs to be made into the size of the first circuit board (MOS board), which can reduce the volume and cost of the heat sink.

The present invention has the advantage of making the control unit 6 into an independent first circuit board 61 and a second circuit board 64 to allow the entity of the control unit to change its installation position according to the internal space of different types of batteries and electric tools. Taking FIGS. 15 and 16 as an example, the battery unit 7 in FIG. 15 is a plug-in type battery that is inserted into the end of the handle portion 20. Those who use this type of battery have a relatively small internal space at the handle portion 20. It is suitable for the two circuit boards 61 and 64 to be separately arranged on the upper and lower sides of the tact switch 65. The battery unit 7 in FIG. 16 is a sliding battery, which is slidably installed at the end of the handle portion 20. The handle portion 20 has a relatively large internal space and is suitable for placing the two circuit boards 61, 64 in parallel. The handle part.

The invention separates the Hall unit and the connection circuit unit of the electric motor, which can indeed achieve the purpose of improving the heat dissipation effect of the invention. In addition, the structural design of the present invention is also beneficial to adjust the rotation speed of the electric motor, thereby adjusting the rotation output of the electric tool.

In addition to being applied to electric tools, the electric motor disclosed in the present invention can also be applied to other electric appliances or equipment with rotation output, such as, but not limited to, electric bicycles, electric motorcycles, electric lawn mowers, etc.

The above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited by this, all simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the patent specification still belong to the present invention. The scope of invention patents.

2: housing unit 20: Grip 201: Tool head 21: The first shell 211: bracket slot 22: second shell 221: bracket slot 23: bracket 231: Body 232: Bracket 233: Clip 24: setting space 25: Motor front cover 26: Motor back cover 261: conductive sheet 261: open 27: Positioning piece 28: Motor space 3: electric motor 31: Rotor 311: shaft 32: stator 321: Yoke 322: pole 322a~322f: pole part 323: Winding Frame Department 33: Coil module 332: Coil 332a~332f: coil 333: Surround part 333a~333d: Surround contact 334: Wiring Department 334a~334c: Wiring section 335: free end 4: Hall unit 41: Hall circuit board 411: Snap Slot 412: piercing hole 42: Hall module 421: Hall element 5: Connection circuit unit 51: Connection circuit board 52: Connection circuit 53: power interface 54: gap 55: short circuit 521: Setting Department 522: Clamping part 6: Control unit 61: The first circuit board 62: heat sink 64: second circuit board 65: Touch switch 7: Battery unit 8: Cooling unit X: winding direction O: Central connection point

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: 1 and 2 are a schematic diagram and a partial cross-sectional view of the basic structure of a conventional electric tool; Fig. 3 is an incomplete perspective view of the first preferred embodiment of the electric tool of the present invention; 4 is an incomplete three-dimensional exploded view of the electric tool and its electric motor according to the first preferred embodiment of the present invention; Fig. 5 is an incomplete perspective view of the electric motor of the first preferred embodiment; Figure 6 is a schematic cross-sectional view taken along the line VI-VI in Figure 5; FIG. 7 is an incomplete schematic diagram of the first preferred embodiment to illustrate the location of a control unit; 8 and 9 are an incomplete three-dimensional schematic diagram and an exploded view of the second preferred embodiment of the electric tool and its electric motor of the present invention; 10 is a schematic cross-sectional view of the electric motor of the second preferred embodiment along the line X-X in FIG. 8; 11 and 12 are incomplete schematic diagrams of the electric motor of the second preferred embodiment to illustrate the winding method of a coil module; FIG. 13 is a schematic diagram of a circuit of the coil module of the second preferred embodiment; and FIG. 14 is an incomplete exploded view of the electric motor of the second preferred embodiment, to illustrate another hall circuit board A way.

Figure 15 is an incomplete view of the third preferred embodiment of the power tool of the present invention.

Figure 16 is an incomplete view of the fourth preferred embodiment of the power tool of the present invention.

2: housing unit

20: Grip

21: The first shell

211: bracket slot

22: second shell

221: bracket slot

23: bracket

231: Body

24: setting space

3: electric motor

4: Hall unit

41: Hall circuit board

411: Snap Slot

42: Hall module

421: Hall element

5: Connection circuit unit

232: Bracket

233: Clip

51: Connection circuit board

8: Cooling unit

Claims (23)

An electric motor includes: a rotor with a rotating shaft; a stator that surrounds the rotor and the rotor can rotate in the stator; a coil module with a plurality of coils wound around the stator; and a Hall unit, including A Hall circuit board arranged around the rotation axis of the rotor, and a pair of Hall modules arranged on the Hall circuit board corresponding to the rotor and used for sensing the rotation of the rotor; and a wiring circuit unit independent of the Hall The circuit board also includes a three-phase power interface, and the connection circuit unit electrically connects the coils and groups the coils to the power interfaces. The electric motor according to claim 1, wherein the connection circuit unit includes: a connection circuit board independent of the Hall circuit board and surrounding the rotating shaft, and a connection circuit provided on the connection circuit board, the power supplies The interface is arranged on the wiring circuit board; the wiring circuit is electrically connected to the coils and the coils are grouped and electrically connected to the power interfaces. The electric motor according to claim 2, wherein the wiring circuit board and the Hall circuit board are arranged in inner and outer circles. The electric motor according to claim 3, wherein the wiring circuit board is arranged around the periphery of the Hall circuit board, and there is a gap between the two. The electric motor according to claim 1, wherein the stator has a cylindrical yoke; a plurality of poles are arranged around the inner circumferential surface of the yoke, and a bobbin part is arranged on the yoke One end of the part; the coils of the coil module are respectively wound around the pole parts; the coil module has a surrounding part to connect the wires The wire is wound around the winding frame part, and three extending from the surrounding part and respectively serving as the connection parts of the power interfaces; the connection circuit unit also includes a short-circuit piece, which is arranged on the winding frame part, the short-circuit piece The surrounding parts are contacted and the coils are electrically connected. The electric motor according to claim 5, wherein the coils, the surrounding part and the three-wire part are formed by one wire. The electric motor according to claim 1, wherein the installation angle of the Hall circuit board can be adjusted. The electric motor according to claim 1, further comprising: a first motor cover and a second motor cover that cooperate; a motor space formed between the two motor covers; the electric motor is installed In the motor space. The electric motor according to claim 8, wherein the Hall circuit board has a plurality of through holes; and further includes: a plurality of positioning members respectively penetrated through the through holes and detachably connected to the first Or in one of the second motor covers, the extension length of each through hole around the rotating shaft is greater than the radial width of the corresponding positioning member. The electric motor according to claim 3, further comprising: a first motor cover and a second motor cover that are matched; a motor space formed between the two motor covers; three conductive sheets, arranged At one of the first or second motor cover; the three wiring portions are respectively electrically connected to the three conductive sheets. An electric tool comprising: a housing unit; a battery unit arranged on the lower side of the housing unit; an electric motor arranged in the housing unit, including a rotor with a rotating shaft, a stator surrounding the rotor, and A coil module with a plurality of coils wound around the stator; A heat dissipation unit corresponding to the electric motor; A Hall unit, which is spaced apart from the heat dissipation unit along the longitudinal direction of the rotating shaft, includes a Hall circuit board disposed on the housing unit around the rotating shaft, and a corresponding rotor disposed on the Hall circuit board for sensing The Hall module for rotating the rotor; A wiring circuit unit, independent of the Hall circuit board and including a three-phase power interface, the wiring circuit unit is electrically connected to the coils and the coil groups are electrically connected to the power interfaces; and A control unit is arranged in the housing unit, electrically connected to the battery unit, the electric motor and the Hall unit, and is located between the electric motor and the battery unit. The electric tool according to claim 11, wherein the wiring circuit unit further includes a wiring circuit board independent of the Hall circuit board and surrounding the rotating shaft, and a wiring circuit provided on the wiring circuit board, the power supply The interface is arranged on the wiring circuit board, and the wiring circuit is electrically connected to the coils and the coils are grouped and electrically connected to the power interfaces. The electric tool according to claim 11, wherein the stator has a cylindrical yoke, a plurality of poles extending inward from the inner circumferential surface of the yoke, and a longitudinal direction of the yoke. The bobbin part at one end of the yoke, the coil module has a plurality of coils respectively wound around the pole parts, a surrounding part connected with the coils and wound around the bobbin part, and three The surrounding portions extend and respectively serve as the connection portions of the power interfaces. The wiring circuit unit further includes a short-circuit piece arranged on the bobbin portion, and the short-circuit piece contacts the surrounding portion and electrically connects the coils. The electric tool according to claim 11, wherein the housing unit includes a motor front cover and a motor rear cover that cooperates with the motor front cover to define a motor space for the electric motor and the Hall unit, the The Hall circuit board is arranged on one of the back cover of the motor or the front cover of the motor corresponding to the rotor. The electric tool according to claim 14, wherein the housing unit further includes a plurality of positioning members that pass through the Hall circuit board and can be detachably connected to one of the motor back cover or the motor front cover, and the Hall circuit The plate has a plurality of through holes respectively for the positioning members to penetrate, and the extension length of each through hole around the rotating shaft is greater than the radial width of the corresponding positioning member. The electric tool according to claim 11, wherein the housing unit includes a first housing, a second housing that cooperates with the first housing and defines an installation space for the electric motor and the Hall unit to be installed, and A bracket arranged on the first shell and the second shell for the Hall circuit board. The electric tool according to claim 16, wherein the bracket has a ring-shaped body part for the Hall circuit board to be installed, and a plurality of parts extend outward from the body part and are clamped on the first housing and the The bracket part of the second housing. The electric tool according to claim 16, wherein the main body of the bracket has a plurality of buckles, and the Hall circuit board has a plurality of buckle slots for the buckles to buckle, respectively. The electric tool according to claim 11, wherein the control unit has a first circuit unit and a second circuit unit electrically connected, and the two circuit units are separately arranged. The electric tool according to claim 19, wherein the housing unit has a handle portion located between the electric motor and the battery unit; the control unit has a tactile switch provided on the handle portion; the first The loop unit and the second loop unit are respectively located on the upper and lower sides of the tact switch. The electric tool according to claim 19, wherein the housing unit has a handle portion located between the electric motor and the battery unit; the control unit has a tactile switch provided on the handle portion; the first The loop unit and the second loop unit are located between the tact switch and the battery unit. The electric tool according to claim 20 or 21, wherein the first circuit unit has a first circuit board, a drive circuit, and a plurality of power switch elements provided on the first circuit; the second circuit unit has A second circuit board and a control loop control the power switch element of the first loop unit. The electric tool according to claim 22, wherein a heat sink is provided on a surface of the first circuit board.

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