Alternating current polishing machine

Abstract

The utility model discloses an alternating current polishing machine. The alternating current polishing machine comprises an output shaft, a brushless motor, a transmission mechanism, a machine shell, a control assembly and an anti-electromagnetic interference device, the output shaft is used for driving a working accessory to move, the brushless motor is provided with or connected with a motor shaft, the transmission mechanism is used for achieving transmission between the motor shaft and the output shaft, and the machine shell forms a holding part for a user to hold. The control assembly comprises a circuit board assembly and a circuit element, and the anti-electromagnetic interference device is used for suppressing electromagnetic interference. The nominal power of the whole brushless motor is greater than 500W and less than 2500W; the distance between the tail of the machine shell and the center line of the output shaft is the first length L3, and the first length L3 is smaller than or equal to 450 mm. According to the alternating current polishing machine, due to the arrangement, the size of the brushless motor is not too large, the overall length of the machine shell is short, and miniaturization can be achieved easily.

Description

Technical Field

[0001] This application relates to a power tool, specifically an AC polishing machine. Background Technology

[0002] A polishing machine, in related technologies, is a grinding tool that uses an electric motor to drive a polishing disc to rotate at high speed, thereby polishing the surface of a workpiece. Also known as a grinding machine, polishing machines are commonly used for mechanical grinding, polishing, and waxing. Polishing discs include sponge and wool discs. The combined action of the disc and polishing compound rubs the surface to be polished, achieving the purpose of removing paint contamination, oxide layers, and shallow scratches.

[0003] Polishing machines require a motor for power. Existing polishing machines are becoming increasingly larger in size due to the pursuit of high motor power, which makes them more difficult for users to hold and operate.

[0004] This section provides background information related to this application, which is not necessarily prior art. Utility Model Content

[0005] One object of this application is to solve or at least alleviate some or all of the aforementioned problems. To this end, one object of this application is to provide an AC polishing machine that is small in size, thereby miniaturizing the AC polishing machine.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] An AC polishing machine includes: an output shaft for driving the movement of a working accessory; a brushless motor having or connected to a motor shaft; a transmission mechanism for transmitting power between the motor shaft and the output shaft; a housing forming a grip for a user to hold; a control assembly including a circuit board assembly and circuit elements; and an electromagnetic interference suppression device for suppressing electromagnetic interference; the nominal power of the brushless motor is greater than 500W and less than 2500W; the distance from the tail of the housing to the center line of the output shaft is a first length L3, and the first length L3 is less than or equal to 450mm.

[0008] In some embodiments, the circuit board assembly includes at least a first circuit board and a second circuit board, which, when viewed from a direction perpendicular to the first circuit board, at least partially overlap.

[0009] In some embodiments, the circuit board assembly includes at least a first circuit board and a second circuit board, which, when viewed from a direction perpendicular to the first circuit board, at least partially overlap, the area of ​​the first circuit board is greater than or equal to the area of ​​the second circuit board, and the maximum length L of the control component along the extension direction of the control component is less than or equal to 75 mm.

[0010] In some embodiments, the working attachment is used to clamp a polishing disc, wherein the projected area of ​​the first circuit board on the polishing plane of the polishing disc is less than or equal to 3000 square millimeters; and / or, the projected area of ​​the second circuit board on the polishing plane of the polishing disc is less than or equal to 2500 square millimeters.

[0011] In some embodiments, the electromagnetic interference suppression device includes an electromagnetic interference suppression circuit board, which is configured as a single-board structure.

[0012] In some embodiments, the maximum length of the electromagnetic interference suppression circuit board is less than 65mm; or, the maximum length of the electromagnetic interference suppression circuit board is less than 55mm; or, the maximum length of the electromagnetic interference suppression circuit board is less than 45mm.

[0013] In some embodiments, the area of ​​the electromagnetic interference resistant circuit board is less than or equal to 1500 planar millimeters.

[0014] In some embodiments, the AC polishing machine further includes a fan mounted on the motor shaft, the fan being located between the brushless motor and the control component.

[0015] In some embodiments, a first air vent located in front of the brushless motor, a second air vent located at the control component, and a third air vent located at the rear end of the grip are formed on the housing, and a cooling airflow is formed from the first air vent and from the second air vent and the third air vent under the action of the fan.

[0016] In some embodiments, a first air vent located in front of the brushless motor, a second air vent located at the control component, a third air vent located at the rear end of the grip portion, and at least one fourth air vent radially opposite to the fan are formed on the housing, and a cooling airflow is formed from the first air vent, the second air vent, and the third air vent and from the fourth air vent under the action of the fan.

[0017] In some embodiments, the brushless motor includes a first bearing supported at the front end of the motor shaft, the first bearing at least partially overlapping the stator of the brushless motor in the axial direction of the motor shaft.

[0018] In some embodiments, the brushless motor includes a second bearing supported at the rear end of the motor shaft, the second bearing at least partially overlapping the fan in the axial direction of the motor shaft.

[0019] In some embodiments, the control component includes a circuit board assembly, wherein the plane of the circuit board assembly is arranged at an angle to the axis of the motor shaft.

[0020] In some embodiments, the plane in which the circuit board assembly is located is substantially perpendicular to the axis of the motor shaft.

[0021] In some embodiments, the circuit board assembly includes at least one circuit board, which is a non-circular plate with sidewalls formed by arcuate surfaces and planes.

[0022] In some embodiments, the circuit board assembly includes a plurality of circuit boards, all of which are perpendicular to the axial direction of the motor shaft.

[0023] In some embodiments, the perimeter D1 of the grip portion along the midline is less than 135 mm.

[0024] In some embodiments, the perimeter D2 of the motor housing at the stator cleavage of the brushless motor is less than or equal to 235 mm.

[0025] In some embodiments, the power of the brushless motor is greater than or equal to 1000W and less than or equal to 2000W.

[0026] In some embodiments, the stack length of the brushless motor is greater than or equal to 10 mm and less than or equal to 50 mm.

[0027] In some embodiments, the outer diameter of the brushless motor is greater than or equal to 30 mm and less than or equal to 65 mm.

[0028] The advantages of this application are:

[0029] The AC polishing machine provided in this application includes an output shaft, a brushless motor, a transmission mechanism, a housing, a control component, and an electromagnetic interference suppression device. The output shaft drives the movement of the working attachments. The brushless motor has or is connected to a motor shaft. The transmission mechanism enables transmission between the motor shaft and the output shaft. The housing forms a grip for the user to hold. The control component includes a circuit board assembly and circuit elements. The electromagnetic interference suppression device is used to suppress electromagnetic interference. Furthermore, the nominal power of the entire brushless motor is greater than 500W and less than 2500W. The distance from the tail of the housing to the center line of the output shaft is a first length L3, which is less than or equal to 390mm. This configuration of the AC polishing machine prevents the brushless motor from becoming too large and keeps the overall length of the housing short, facilitating miniaturization. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a power tool;

[0031] Figure 2 This is an exploded view of power tools;

[0032] Figure 3 This is the front view of the power tool after removing the working attachments;

[0033] Figure 4 This is a schematic diagram of a brushless motor, transmission mechanism, and output shaft from a certain perspective.

[0034] Figure 5 yes Figure 4 A schematic diagram of the structure shown from another perspective;

[0035] Figure 6 yes Figure 4 A cross-sectional view of the structure shown;

[0036] Figure 7 This is a cross-sectional view of a brushless motor;

[0037] Figure 8 This is an exploded view of the first type of control component;

[0038] Figure 9 This is a dimensional diagram of a power tool;

[0039] Figure 10 This is a schematic diagram of the dimensions of the circuit board for the first type of control component;

[0040] Figure 11 This is a layout diagram of the circuit elements of the first type of control component;

[0041] Figure 12 This is a schematic diagram of a portion of the structure of the first type of control component;

[0042] Figure 13 yes Figure 12 A schematic diagram of the structure shown from another perspective;

[0043] Figure 14 yes Figure 12 A schematic diagram showing the removal of the control box in the structure shown;

[0044] Figure 15 This is a schematic diagram of the heat sink for the first type of control component;

[0045] Figure 16 This is an exploded view of another type of power tool;

[0046] Figure 17 This is a schematic diagram of the second type of control component;

[0047] Figure 18 yes Figure 17 A schematic diagram showing the removal of the control box in the structure shown;

[0048] Figure 19 yes Figure 18 Exploded view of the structure shown;

[0049] Figure 20 yes Figure 18 A cross-sectional view of the structure shown;

[0050] Figure 21 This is an exploded view of yet another type of power tool;

[0051] Figure 22 This is a schematic diagram of the third type of control component;

[0052] Figure 23 yes Figure 22 Exploded view of the structure shown;

[0053] Figure 24 yes Figure 23 A schematic diagram of the structure shown from another perspective;

[0054] Figure 25 This is a layout diagram of the circuit elements of the third type of control component;

[0055] Figure 26 This is a schematic diagram showing heat dissipation holes on the circuit board of the third type of control component;

[0056] Figure 27 This is a schematic diagram of an electromagnetic interference suppression device;

[0057] Figure 28 This is a diagram showing the location of the motor switch;

[0058] Figure 29 This is a diagram of a ventilation opening on a power tool;

[0059] Figure 30 This is a schematic diagram of the first flow path for cooling airflow in power tools;

[0060] Figure 31 This is a schematic diagram of the second flow path for the cooling airflow of a power tool.

[0061] 10. Housing; 101. First housing; 102. Second housing; 103. Third housing; 104. First air vent; 105. Second air vent; 106. Third air vent; 107. Fourth air vent;

[0062] 11. Grip section; 12. Output shaft; 13. Working accessories;

[0063] 14. Brushless motor; 141. Motor shaft; 142. Stator; 143. Rotor; 144. Motor housing; 145. First bearing; 146. Second bearing; 147. Bearing positioning component; 148. Noise-reducing metal ring;

[0064] 15. Transmission mechanism; 151. Planetary gear assembly; 152. First bevel gear; 153. Second bevel gear; 154. First reduction shaft; 155. Second reduction shaft;

[0065] 16. Fan; 17. Power cord; 18. Motor switch;

[0066] 20. Control component; 21. Circuit board assembly; 201. Board surface; 202. Plane; 203. Curved surface; 204. Non-circular board component; 211. First circuit board; 2111. Heat dissipation hole; 212. Second circuit board; 22. Circuit element; 221. Electronic switch; 2211. First mounting port; 222. Rectifier; 2221. Second mounting port; 223. Second capacitor; 23. Heat sink; 231. Third mounting port; 232. First heat dissipation section 233. Second heat dissipation unit; 234. First main mounting plate; 235. Heat dissipation rib; 2351. First airflow channel; 2352. Second airflow channel; 2354. First heat dissipation rib; 2355. Second heat dissipation rib; 236. Second main mounting plate; 237. Third heat dissipation rib; 2301. First radiator; 2302. Second radiator; 2303. Third radiator; 2304. Fourth radiator; 24. Control box; 25. Glue;

[0067] 30. Electromagnetic interference suppression device; 31. Electromagnetic interference suppression circuit board; 32. First capacitor; 33. Resistor; 34. Inductor; 35. AC socket; 36. Mounting box;

[0068] 40. Speed ​​controller. Detailed Implementation

[0069] Before explaining any implementation of this application in detail, it should be understood that this application is not limited to its application to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0070] In this application, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0071] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this application generally indicates that the preceding and following related objects have an "and / or" relationship.

[0072] In this application, the terms "connection," "combination," "coupling," and "installation" can refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, a direct connection refers to two parts or components being connected together without the need for an intermediary, while an indirect connection refers to two parts or components each being connected to at least one intermediary, with the connection achieved through the intermediary. Furthermore, "connection" and "coupling" are not limited to physical or mechanical connections or couplings, but can also include electrical connections or couplings.

[0073] In this application, those skilled in the art will understand that relative terms (e.g., “about,” “approximately,” “basically,” etc.) used in conjunction with quantities or conditions are to include the values ​​and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances associated with the particular value due to manufacturing, assembly, use, etc. Such terms should also be considered as disclosing a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​not using relative terms should also be disclosed as specific values ​​with tolerances. Furthermore, “basically” when expressing relative angular relationships (e.g., substantially parallel, substantially perpendicular) may refer to a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) added to or subtracted from the indicated angle.

[0074] In this application, those skilled in the art will understand that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0075] In this application, the directional terms "upper," "lower," "left," "right," "front," and "rear" are used to describe the orientation and positional relationships shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when an element is mentioned as being connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected through an intermediate element. It should also be understood that directional terms such as upper side, lower side, left side, right side, front side, and rear side not only represent positive orientation but can also be understood as lateral orientation. For example, "below" can include directly below, lower left, lower right, lower front, and lower rear.

[0076] In this application, the terms "controller," "processor," "central processing unit," "CPU," and "MCU" are used interchangeably. When using the unit "controller," "processor," "central processing unit," "CPU," or "MCU" to perform a specific function, unless otherwise stated, these functions may be performed by a single or multiple of the aforementioned units.

[0077] In this application, the terms "device," "module," or "unit" are used to describe devices that can be implemented in hardware or software to perform a specific function.

[0078] In this application, the terms “calculation,” “judgment,” “control,” “determine,” “identify,” etc., refer to the operation and process of a computer system or similar electronic computing device (e.g., controller, processor, etc.).

[0079] This application provides a power tool. In some embodiments, the power tool can be an AC polisher. Of course, in other embodiments, the power tool can be made into a tool for performing other tasks, such as an impact drill or an electric screwdriver, by changing the working attachments as needed.

[0080] like Figures 1 to 6 As shown, the power tool includes a housing 10, a brushless motor 14, a transmission mechanism 15, an output shaft 12, a working attachment 13, a fan 16, a control component 20, an electromagnetic interference suppression device 30, and a speed controller 40.

[0081] The housing 10 is the main mounting and protective component of the power tool. The housing 10 can be a single molded part or formed by connecting multiple parts. For example... Figure 2As shown, the housing 10 includes a first housing 101, a second housing 102, and a third housing 103. Both the first housing 101 and the second housing 102 are half-shells, joined side-by-side to form the rear housing of the housing 10. The control component 20, the electromagnetic interference suppression device 30, and the speed controller 40 are all installed inside the rear housing. A through-hole for the power cord 17 to extend into the rear of the rear housing is formed. The third housing 103 is the front housing of the power tool. The third housing 103 can be formed by joining two half-shells or it can be a single molded part. The transmission mechanism 15 and the top of the output shaft 12 are placed inside the third housing 103, and a through-hole for the output shaft 12 to extend out of the lower part of the third housing 103 is formed.

[0082] The housing 10 portion forms a grip 11 for the user to hold and operate the power tool. In some embodiments, the rear housing portion is the grip 11, and an anti-slip structure is provided on the grip 11 to improve the stability of the user holding the grip 11. The anti-slip structure can be an anti-slip rubber sleeve, anti-slip texture, etc.

[0083] In some embodiments, such as Figure 3 As shown, the circumference D1 of the grip portion 11 along the midline is less than 135 mm. In one embodiment, the circumference D1 of the grip portion 11 along the midline is 133 mm; in another embodiment, the circumference D1 of the grip portion 11 along the midline is 130 mm; in yet another embodiment, the circumference D1 of the grip portion 11 along the midline is 127 mm; in one embodiment, the circumference D1 of the grip portion 11 along the midline is 122 mm; in one embodiment, the circumference D1 of the grip portion 11 along the midline is 119 mm; and in yet another embodiment, the circumference D1 of the grip portion 11 along the midline is 115 mm.

[0084] The brushless motor 14 is housed within the housing 10. Specifically, the brushless motor 14 can be housed within the front housing or the rear housing. In some parallel embodiments, the motor housing 144 of the brushless motor 14 is externally mounted as part of the housing 10, and the motor housing 144 is connected between the front housing and the rear housing.

[0085] In addition to the motor housing 144, the brushless motor 14 also includes a stator 142, a rotor 143, a bearing assembly, etc., disposed within the motor housing 144. In some embodiments, the bearing assembly of the brushless motor 14 includes a first bearing 145 supported at the front end of the motor shaft 141, and the first bearing 145 at least partially overlaps with the stator 142 of the brushless motor 14 in the axial direction of the motor shaft 141. This arrangement improves the compactness of the power tool's internal components, which is beneficial for miniaturizing the power tool.

[0086] In one specific embodiment, this application moves the bearing positioning structure that fixes the first bearing 145 15mm inward toward the inside of the motor housing 144 and into the stator 142; in other embodiments, this moving distance can be adjusted as needed. The bearing positioning structure can be a bearing seat or a positioning groove.

[0087] Continue to refer to Figure 5 and Figure 6 As shown, the fan 16 is mounted on the motor shaft 141 and is located between the brushless motor 14 and the control assembly 20. In some embodiments, the fan 16 is mounted on the rear end of the motor shaft 141 of the brushless motor 14, and the bearing assembly of the brushless motor 14 further includes a second bearing 146 supported on the rear end of the motor shaft 141, the second bearing 146 at least partially overlapping the fan 16 in the axial direction of the motor shaft 141.

[0088] In one specific embodiment, this application moves the bearing positioning member 147, which fixes the second bearing 146, 14.5 mm inward toward the inner side of the motor housing 144 until it enters the inner cavity of the fan 16; in other embodiments, this moving distance can be adjusted as needed. The bearing positioning member 147 can be a bearing seat or a positioning groove.

[0089] like Figure 7 As shown, in some embodiments, a noise-reducing metal ring 148 is also sleeved on the outside of the stator 142. The noise-reducing metal ring 148 is in close contact with the outer wall surface of the stator 142, which reduces the vibration of the stator 142 and achieves a noise reduction effect. In one embodiment, multiple noise-reducing metal rings 148 are provided, and the multiple noise-reducing metal rings 148 are spaced apart in the direction of the motor shaft 141 of the brushless motor 14.

[0090] In some embodiments, the power of the brushless motor 14 is greater than or equal to 1000W and less than or equal to 2000W. In this embodiment, the rated power of the brushless motor 14 is 1400W.

[0091] In some embodiments, the stack length of the brushless motor 14 is greater than or equal to 10 mm and less than or equal to 50 mm. In one embodiment, the stack length of the brushless motor 14 is 15 mm; in another embodiment, the stack length of the brushless motor 14 is 25 mm; in yet another embodiment, the stack length of the brushless motor 14 is 35 mm; in yet another embodiment, the stack length of the brushless motor 14 is 35 mm; and in yet another embodiment, the stack length of the brushless motor 14 is 45 mm.

[0092] In some embodiments, the outer diameter of the brushless motor 14 is greater than or equal to 30 mm and less than or equal to 65 mm. In one embodiment, the outer diameter of the brushless motor 14 is 35 mm; in another embodiment, the outer diameter of the brushless motor 14 is 40 mm; in yet another embodiment, the outer diameter of the brushless motor 14 is 50 mm; and in still another embodiment, the outer diameter of the brushless motor 14 is 60 mm.

[0093] Continue to refer to Figure 3 As shown, in some embodiments, the perimeter D2 of the motor housing 144 of the brushless motor 14 at the branch line in the stator 142 is less than or equal to 235 mm. In one embodiment, the perimeter D2 of the motor housing 144 at the branch line in the stator 142 is 230 mm; in one embodiment, the perimeter D2 of the motor housing 144 at the branch line in the stator 142 is 225 mm; in one embodiment, the perimeter D2 of the motor housing 144 at the branch line in the stator 142 is 222 mm; in one embodiment, the perimeter D2 of the motor housing 144 at the branch line in the stator 142 is 219 mm; in one embodiment, the perimeter D2 of the motor housing 144 at the branch line in the stator 142 is 215 mm; in one embodiment, the perimeter D2 of the motor housing 144 at the branch line in the stator 142 is 210 mm.

[0094] In some embodiments, the nominal power of the brushless motor 14 is greater than 500W and less than 2500W. It should be noted that the nominal power refers to the overall power of the power tool, specifically the overall power of an AC polisher. For AC polishers, the nominal power refers to the power value indicated on the machine's nameplate, which is also the machine's rated power value. In one embodiment, the nominal power of the brushless motor 14 is 800W; in another embodiment, it is 1100W; in yet another, it is 1300W; in one embodiment, it is 1600W; and in yet another, it is 1800W.

[0095] In some parallel embodiments, the nominal power of the brushless motor 14 is greater than 1000W and less than 2000W.

[0096] In some parallel embodiments, the nominal power of the brushless motor 14 is greater than 1200W and less than 1500W.

[0097] Continue to refer to Figures 4 to 6As shown, the brushless motor 14 is provided with or connected to a motor shaft 141, and the transmission mechanism 15 is connected between the motor shaft 141 and the output shaft 12, and is used to realize transmission between the motor shaft 141 and the output shaft 12. Compared with the cumbersome brush replacement of existing polishing machines using series-wound brushed motors, this application can effectively solve this problem by using the brushless motor 14.

[0098] When the power tool is in operation, the motor shaft 141 is basically horizontal, while the output shaft 12 is basically vertical. To achieve power transmission between the motor shaft 141 and the output shaft 12, as follows: Figure 6 As shown, the transmission mechanism 15 includes a planetary gear assembly 151, a first bevel gear 152, a second bevel gear 153, a first reduction shaft 154, and a second reduction shaft 155. The motor shaft 141 of the brushless motor 14 is coaxially connected to the first reduction shaft 154. The first reduction shaft 154 is connected to the sun gear of the planetary gear assembly 151. The second reduction shaft 155 is connected to the planet carrier of the planetary gear assembly 151. The first bevel gear 152 is formed or connected to the second reduction shaft 155, and the second bevel gear 153 is formed or connected to the output shaft 12.

[0099] When the motor shaft 141 of the brushless motor 14 rotates, the power is transmitted to the output shaft 12 in sequence through the first reduction shaft 154, the planetary gear assembly 151, the second reduction shaft 155, the first bevel gear 152 and the second bevel gear 153, so that the output shaft 12 can drive the working attachment 13 to rotate. The working attachment 13 can hold the polishing disc (not shown in the figure) to grind and polish the workpiece to be processed.

[0100] As for the polishing pad, it is generally horizontally positioned, and the diameter of the polishing pad is greater than or equal to 180 mm and less than or equal to 230 mm. In one embodiment, the diameter of the polishing pad is 180 mm; in another embodiment, the diameter of the polishing pad is 190 mm; in yet another embodiment, the diameter of the polishing pad is 200 mm; in one embodiment, the diameter of the polishing pad is 210 mm; in another embodiment, the diameter of the polishing pad is 220 mm; and in yet another embodiment, the diameter of the polishing pad is 230 mm.

[0101] The control component 20 is used to control the brushless motor 14 and supply power to the brushless motor 14. Figures 8 to 15 The first structure of the control component 20 is shown. Figures 16 to 20 The second structure of the control component 20 is shown. Figures 21 to 26 The diagram shows a third structure of the control component 20. The specific structure of the control component 20 is described below. It should be noted beforehand that some components in the three structures described above are interchangeable in the control component 20, but only one structure is shown in the accompanying drawings.

[0102] Specifically, the control assembly 20 includes a circuit board assembly 21, circuit elements 22, and a control box 24. Both the circuit board assembly 21 and the circuit elements 22 are housed within the control box 24, with the circuit elements 22 integrated onto the circuit board assembly 21. To secure the circuit board assembly 21 and circuit elements 22 within the control box 24, after the circuit elements 22 are mounted onto the circuit board assembly 21, the resulting assembly is placed inside the control box 24, and a glue 25 is injected into the control box 24 to further secure the circuit board assembly 21 and circuit elements 22. Furthermore, injecting the glue 25 into the control box 24 also provides a certain degree of waterproofing and dustproofing. It should be noted that after injecting the glue 25 into the control box 24, a portion of the circuit elements 22 remains exposed outside the glue. This portion requires dustproofing; therefore, protection, such as forming a sealing layer, is needed on the exposed metal of the circuit elements 22 to prevent failure in the presence of water and dust.

[0103] In some embodiments, the plane containing the circuit board assembly 21 is set at an angle to the axis of the motor shaft 141. In another embodiment, the plane containing the circuit board assembly 21 is substantially perpendicular to the axis of the motor shaft 141.

[0104] The circuit board assembly 21 includes at least one circuit board. In some embodiments, the circuit board is arranged perpendicular to the axial direction of the motor shaft 141. In some embodiments, such as Figure 8 , Figure 18 and Figure 23 As shown, the circuit board assembly 21 includes two circuit boards, a first circuit board 211 and a second circuit board 212, which are electrically connected to each other. The first circuit board 211 and the second circuit board 212 are arranged substantially parallel to each other. When viewed from a direction perpendicular to the first circuit board 211, the first circuit board 211 and the second circuit board 212 at least partially overlap. The area of ​​the first circuit board 211 is greater than or equal to the area of ​​the second circuit board 212, and as shown... Figure 9 As shown, the maximum length L of the control component 20 along the extension direction of the grip 11 is less than or equal to 75 mm. By setting two circuit boards, different types of circuit elements 22 can be electrically connected on different circuit boards. This arrangement reduces the space occupied by the control component 20 and facilitates the miniaturization of the power tool.

[0105] In some embodiments, such as Figure 10As shown, the maximum length L1 of the first circuit board 211 is less than or equal to 75 mm. In one specific embodiment, the maximum length L1 of the first circuit board 211 is 72 mm; in another specific embodiment, the maximum length L1 of the first circuit board 211 is 70 mm; in yet another specific embodiment, the maximum length L1 of the first circuit board 211 is 67 mm; in yet another specific embodiment, the maximum length L1 of the first circuit board 211 is 65 mm; and in yet another specific embodiment, the maximum length L1 of the first circuit board 211 is 60 mm.

[0106] In some embodiments, continue to refer to Figure 10 As shown, the maximum length L2 of the second circuit board 212 is less than or equal to 60 mm. In one specific embodiment, the maximum length L2 of the second circuit board 212 is 58 mm; in another specific embodiment, the maximum length L2 of the second circuit board 212 is 55 mm; in yet another specific embodiment, the maximum length L2 of the second circuit board 212 is 53 mm; in one specific embodiment, the maximum length L2 of the second circuit board 212 is 51 mm; and in yet another specific embodiment, the maximum length L2 of the second circuit board 212 is 48 mm.

[0107] In one embodiment, the length of the first circuit board 211 is 72mm and the width W of the first circuit board 211 is 39mm; the length of the second circuit board 212 is 60mm and the width W of the second circuit board 212 is 39mm.

[0108] In some embodiments, the maximum length of the first circuit board 211 along the extending direction of the grip portion 11 is less than or equal to 75 mm. In some embodiments, the maximum length L2 of the second circuit board 212 along the extending direction of the grip portion 11 is less than or equal to 60 mm. It should be noted that the maximum length of the first circuit board 211 along the extending direction of the grip portion 11 is related to the orientation of the first circuit board 211 within the grip portion 11. When the first circuit board 211 is parallel to the extending direction of the grip portion 11, the maximum length of the first circuit board 211 along the extending direction of the grip portion 11 is the aforementioned L1. When the first circuit board 211 is inclined relative to the extending direction of the grip portion 11, the maximum length of the first circuit board 211 along the extending direction of the grip portion 11 is equal to the length of the projection of the first circuit board 211 onto the extending direction of the grip portion 11. The length is less than L1; similarly, the maximum length of the second circuit board 212 is related to the position of the second circuit board 212 in the grip portion 11. When the second circuit board 212 is parallel to the extension direction of the grip portion 11, the maximum length of the second circuit board 212 along the extension direction of the grip portion 11 is the aforementioned L2. When the second circuit board 212 is inclined relative to the extension direction of the grip portion 11, the maximum length of the second circuit board 212 along the extension direction of the grip portion 11 is equal to the length of the projection of the second circuit board 212 in the extension direction of the grip portion 11, which is less than L2.

[0109] In some embodiments, the area of ​​the first circuit board 211 is less than or equal to 3000 square millimeters. In one specific embodiment, the area of ​​the first circuit board 211 is 2900 square millimeters; in another specific embodiment, the area of ​​the first circuit board 211 is 2800 square millimeters; in yet another specific embodiment, the area of ​​the first circuit board 211 is 2700 square millimeters; in one specific embodiment, the area of ​​the first circuit board 211 is 2600 square millimeters; in one specific embodiment, the area of ​​the first circuit board 211 is 2500 square millimeters; in one specific embodiment, the area of ​​the first circuit board 211 is 2400 square millimeters; in one specific embodiment, the area of ​​the first circuit board 211 is 2300 square millimeters; in one specific embodiment, the area of ​​the first circuit board 211 is 2200 square millimeters; in one specific embodiment, the area of ​​the first circuit board 211 is 2100 square millimeters; in yet another specific embodiment, the area of ​​the first circuit board 211 is 2000 square millimeters.

[0110] In some embodiments, the area of ​​the second circuit board 212 is less than or equal to 2500 square millimeters. In one specific embodiment, the area of ​​the second circuit board 212 is 2400 square millimeters; in another specific embodiment, the area of ​​the second circuit board 212 is 2300 square millimeters; in yet another specific embodiment, the area of ​​the second circuit board 212 is 2200 square millimeters; and in yet another specific embodiment, the area of ​​the second circuit board 212 is 2100 square millimeters.

[0111] In some embodiments, the projected area of ​​the first circuit board 211 on the polishing plane 202 of the polishing disk is less than or equal to 3000 square millimeters.

[0112] In some embodiments, the projected area of ​​the second circuit board 212 on the polishing plane 202 of the polishing disk is less than or equal to 2500 square millimeters.

[0113] In some embodiments, in a direction perpendicular to the first circuit board 211, the ratio of the area of ​​the overlapping portion of the first circuit board 211 and the second circuit board 212 to the area of ​​the first circuit board 211 is the overlap rate, wherein the overlap rate is greater than or equal to 50%. In one specific embodiment, the overlap rate of the first circuit board 211 and the second circuit board 212 is 49%; in another specific embodiment, the overlap rate is 48%; in yet another specific embodiment, the overlap rate is 47%; in one specific embodiment, the overlap rate is 46%; and in one yet another specific embodiment, the overlap rate is 45%.

[0114] Furthermore, the number of circuit boards included in the circuit board assembly 21 is not limited to two; it can be configured to include three, four, or more circuit boards depending on the requirements. In some embodiments, the circuit board assembly 21 also includes a third circuit board (not shown in the figure). When viewed from a direction perpendicular to the first circuit board 211, the first circuit board 211, the second circuit board 212, and the third circuit board at least partially overlap, and the area of ​​the first circuit board 211 is greater than or equal to the area of ​​the third circuit board. This configuration can further reduce the size of the first circuit board 211 and the second circuit board 212, which is more conducive to the miniaturization of power tools.

[0115] When the number of circuit boards in the circuit board assembly 21 is three, the maximum length L1 of the first circuit board 211 can be effectively reduced, making the maximum length L1 of the first circuit board 211 less than or equal to 65 mm. In one specific embodiment, the maximum length L1 of the first circuit board 211 is 64 mm; in another specific embodiment, the maximum length L1 of the first circuit board 211 is 63 mm; in yet another specific embodiment, the maximum length L1 of the first circuit board 211 is 62 mm; in yet another specific embodiment, the maximum length L1 of the first circuit board 211 is 61 mm; and in yet another specific embodiment, the maximum length L1 of the first circuit board 211 is 60 mm.

[0116] In one embodiment, the first circuit board 211 has a length of 61.5 mm and a width of 44 mm; the second circuit board 212 has a length of 50 mm and a width of 36 mm; and the third circuit board has a length of 63 mm and a width of 20 mm.

[0117] It should be noted that, in order to improve the structural compactness of the control component 20, multiple circuit boards are arranged in parallel. The control component 20 is housed within the housing 10. In some embodiments, such as... Figures 8 to 20 As shown, when the power tool is in operation, the circuit board is basically horizontal and parallel to the central axis of the grip 11; in some parallel embodiments, when the power tool is in operation, such as Figures 21 to 26 As shown, the circuit board is basically vertically arranged and perpendicular to the central axis of the grip 11; of course, in other embodiments, when the power tool is in operation, the circuit board can also be tilted and arranged at an acute or obtuse angle to the central axis of the grip 11.

[0118] Continue to refer to Figure 8 As shown, the circuit element 22 includes multiple electronic switches 221, a rectifier 222, a second capacitor 223, and a control module. In some embodiments, the multiple electronic switches 221, the rectifier 222, and the second capacitor 223 are all fixed on a circuit board. It should be noted that different types of circuit elements 22 can be fixed on the same circuit board or on different circuit boards. In one embodiment, the multiple electronic switches 221, the rectifier 222, and the second capacitor 223 are all fixed on a first circuit board 211, while the control module is located on a second circuit board 212.

[0119] Multiple electronic switches 221 are used to drive the brushless motor 14. Specifically, the multiple electronic switches 221 form a three-phase bridge circuit, and the rectifier 222 forms a DC unit that receives the AC power input from the power line 17 and outputs the DC bus voltage, that is, it converts the AC power input through the power line 17 into pulsating DC power output. The control module is used to control the conduction state of the multiple electronic switches 221, thereby driving the brushless motor 14 to operate normally. In some embodiments, the control module uses a control chip to implement its function.

[0120] In some embodiments, the electronic switch 221 is perpendicular to the circuit board. In some embodiments, the electronic switch 221 is an IGBT, where IGBT represents a field-effect transistor; in some embodiments, the electronic switch 221 is a MOS; in some embodiments, the electronic switch 221 is a FET, where FET represents a field-effect transistor.

[0121] In some embodiments, a plurality of electronic switches 221 are arranged regularly on a first circuit board 211, for example, in rows and columns or in a ring. In one embodiment, such as Figure 11 As shown, the first circuit board 211 is positioned above the second circuit board 212. Six electronic switches 221 are provided, designated 221a, 221b, 221c, 221d, 221e, and 221f, and arranged in two rows of three columns. The rectifier 222 and the multiple electronic switches 221 are arranged side-by-side along the length of the first circuit board 211. Three second capacitors 223 are provided; one is positioned to one side of the electronic switch 221, and the other two are positioned to the sides of the rectifier 222. (Continuing to refer to...) Figure 11 As shown, the three second capacitors 223 are distinguished by 223a, 223b, and 223c respectively.

[0122] In some parallel embodiments, such as Figures 17 to 19 As shown, the first circuit board 211 is located below the second circuit board 212. The number and arrangement of the electronic switch 221 and rectifier 222 remain unchanged. The number of the second capacitor 223 is adjusted to six and is set on the second circuit board 212. The six second capacitors 223 are arranged in a row.

[0123] In some parallel embodiments, such as Figures 21 to 25As shown, the number of electronic switches 221, rectifiers 222, and second capacitors 223 remains unchanged, but their arrangement is adjusted. The six electronic switches 221 are arranged in two rows and three columns, the three second capacitors 223 are placed between the two rows of electronic switches 221, and the rectifier 222 is placed below the three second capacitors 223. Of course, in other embodiments, the arrangement of the electronic switches 221, rectifiers 222, and second capacitors 223 can be flexibly adjusted according to requirements and the internal space of the grip 11.

[0124] Continue to refer to Figure 8 , Figure 18 and Figure 22 As shown, the power tool also includes a radiator 23, which is used to dissipate heat for the control component 20. The number of radiators 23 can be set to one or more as needed.

[0125] In some embodiments, continue to refer to Figures 12 to 15 As shown, when the power tool is in operation, the circuit boards are generally horizontally positioned. The power tool is equipped with a heat sink 23, which is located below the first circuit board 211 and is in contact with the surfaces of multiple electronic switches 221 and rectifiers 222. The first pins of the electronic switches 221 and the second pins of the rectifiers 222 are soldered to the back side of the circuit board. The heat sink 23 can dissipate heat from the electronic switches 221 and rectifiers 222 to prevent overheating and malfunctions. Of course, in other embodiments, the positions of the first circuit board 211 and the second circuit board 212 can be adjusted so that the first circuit board 211 is above the second circuit board 212, and the heat sink 23 is above the first circuit board 211.

[0126] Continue to refer to Figure 15 As shown, the heat sink 23 includes a first heat sink 232 and a second heat sink 233 connected vertically. The first heat sink 232 is basically horizontally arranged and is positioned above a plurality of electronic switches 221 and a rectifier 222. A plurality of airflow channels are formed on the first heat sink 232, which are basically parallel to the first circuit board 211. The second heat sink 233 is inserted between two rows of electronic switches 221 and is in contact with both rows of electronic switches 221 and the rectifier 222. This arrangement can improve the heat dissipation effect and heat dissipation efficiency.

[0127] Continue to refer to Figure 8 and Figure 15As shown, to achieve a fixed connection between the heat sink 23, the electronic switch 221, and the rectifier 222, a first mounting port 2211 is provided on the electronic switch 221, a second mounting port 2221 is provided on the rectifier 222, and multiple third mounting ports 231 are provided on the heat sink 23. The first mounting port 2211 and the third mounting port 231 are connected in a one-to-one correspondence, as are the second mounting ports 2221 and the third mounting ports 231. A first connector passes through the first mounting port 2211 and the third mounting port 231 to fix the electronic switch 221 to the heat sink 23, and a second connector passes through the second mounting port 2221 and the third mounting port 231 to fix the rectifier 222 to the heat sink 23. Screws can be used for both the first and second connectors.

[0128] In one embodiment, four third mounting ports 231 are provided on the second heat dissipation section 233 of the radiator 23, a first mounting port 2211 is provided on each electronic switch 221, and a second mounting port 2221 is provided on the rectifier 222. The first connector passes through the first mounting port 2211 of one electronic switch 221 located on one side of the second heat dissipation section 233, a third mounting port 231 on the radiator 23, and the first mounting port 2211 of another electronic switch 221 located on the other side of the second heat dissipation section 233 to assemble the radiator 23 with the two electronic switches 221. This allows six electronic switches 221 to be fixed to the radiator 23 using only three first connectors, while the remaining third mounting port 231 is for the second connector to pass through.

[0129] In some parallel embodiments, such as Figures 22 to 24 As shown, when the power tool is in operation, the circuit boards are basically set vertically, and there are two heat sinks 23. The two heat sinks 23 are the first heat sink 2301 and the second heat sink 2302, which respectively dissipate heat for each row of electronic switches 221.

[0130] like Figure 23 and Figure 24As shown, in some embodiments, the first heat sink 2301 and the second heat sink 2302 have the same structure. Both the first heat sink 2301 and the second heat sink 2302 include a first main mounting plate 234 and heat dissipation ribs 235. The heat dissipation ribs 235 include a plurality of first heat dissipation ribs 2354 and a plurality of second heat dissipation ribs 2355. The first main mounting plate 234 is an arc-shaped plate, and the first heat dissipation ribs 2354 protrude from the first main mounting plate 234 on the side closer to the circuit element 22, or in other words, closer to the side closer to the second capacitor 223. A first airflow channel 2351 is formed between two adjacent first heat dissipation ribs 2354, and a second airflow channel 2352 is formed between two adjacent second heat dissipation ribs 2355. It should be noted that when installing the first radiator 2301 and the second radiator 2302, the first radiator 2301 and the second radiator 2302 are arranged opposite to each other, so that the two first main body mounting plates 234 protrude in opposite directions. This can improve the smoothness of airflow and thus improve the heat dissipation effect.

[0131] The airflow channels on the two heat sinks 23 of the first heat sink 2301 and the second heat sink 2302 are oriented in an angled manner to the circuit board surface 201. Here, an airflow channel refers to the passage formed between any two adjacent heat dissipation ribs 235 for airflow. A heat sink 23 can have the same airflow channel direction or multiple different airflow channel directions. In this embodiment, the first airflow channel 2351 and the second airflow channel 2352 represent two different airflow channel directions. The circuit board surface 201 can be the surface of the first circuit board 211 or the surface of the second circuit board 212. In this embodiment, since the first circuit board 211 and the second circuit board 212 are substantially parallel, therefore... Figure 24 A schematic diagram of the board surface 201 of the second circuit board 212.

[0132] This power tool, by tilting the airflow channels of the radiator 23 and the board surface 201 of the circuit board, not only reduces the radial dimension of the power tool, making it easier for the user to hold and operate, thus facilitating the miniaturization of the power tool, but also provides better heat dissipation for the control components 20. Figure 24 As shown, the angle between the airflow channel of the heat sink 23 and the surface 201 of the circuit board is represented by α. Figure 24Since the first heat sink 2301 and the second heat sink 2302 have essentially the same structure, the airflow path here is described as the airflow path 2352 formed by the first heat dissipation rib 2354 of the second heat sink 2302. Therefore, in this scheme, one side of the included angle α refers to the airflow path 2352, and the other side refers to the board surface 2112 of the circuit board 201. In some embodiments, the included angle α between the airflow path of the heat sink 23 and the board surface 201 of the circuit board is greater than 0° and less than or equal to 90°. In one embodiment, the included angle α between the airflow path of the heat sink 23 and the board surface 201 of the circuit board is 90°; in another embodiment, the included angle α between the airflow path of the heat sink 23 and the board surface 201 of the circuit board is 60°; in yet another embodiment, the included angle α between the airflow path of the heat sink 23 and the board surface 201 of the circuit board is 30°.

[0133] In some parallel embodiments, the included angle α between the airflow channel of the heat sink 23 and the board surface 201 of the circuit board is greater than 30° and less than or equal to 90°.

[0134] In some parallel embodiments, the included angle α between the airflow channel of the heat sink 23 and the board surface 201 of the circuit board is greater than 50° and less than or equal to 90°.

[0135] Continue to refer to Figure 23 and Figure 24 As shown, in addition to the first radiator 2301 and the second radiator 2302, the control assembly 20 also includes a third radiator 2303, which is used to dissipate heat from the rectifier 222. In some embodiments, the third radiator 2303 includes a second main mounting plate 236 and a plurality of third heat dissipation ribs 237, wherein the second main mounting plate 236 is a flat plate, and the second heat dissipation ribs 237 protrude from the outer side of the third main mounting plate 236, forming an airflow channel between adjacent third heat dissipation ribs 237. It should be noted that after installing the second radiator 2302 and the second radiator 2302, the third radiator 2303 is installed below the second radiator 2302 and the second radiator 2302, with the third heat dissipation ribs 237 protruding downwards. This improves the smoothness of airflow, thereby improving the heat dissipation effect.

[0136] It should be noted that the airflow channels formed on the third radiator 2303 can be arranged parallel to or at an angle to the airflow channels of the first radiator 2301 and the second radiator 2302. Therefore, the range of the included angle α mentioned above also applies to the third radiator 2303.

[0137] like Figure 23 and Figure 24As shown, in order to achieve a fixed connection between the heat sink 23 and the electronic switch 221, a first mounting port 2211 is provided on the electronic switch 221, and multiple third mounting ports 231 are provided on the first heat sink 2301 and the second heat sink 2302 respectively. The first mounting port 2211 and the third mounting port 231 are connected in a one-to-one correspondence. The first connector passes through the first mounting port 2211 and the third mounting port 231 to fix the electronic switch 221 and the heat sink 23.

[0138] In order to achieve a fixed connection between the third heat sink 2303 and the rectifier 222, a second mounting port 2221 is provided on the rectifier 222 and a third mounting port 231 is provided on the third heat sink 2303. The second mounting port 2221 and the third mounting port 231 are connected in a one-to-one correspondence. The second connector passes through the second mounting port 2221 and the third mounting port 231 to fix the rectifier 222 and the heat sink 23.

[0139] In one embodiment, three third mounting ports 231 are respectively provided on the first heat sink 2301 and the second heat sink 2302, one third mounting port 231 is provided on the third heat sink 2303, a first mounting port 2211 is provided on each electronic switch 221, and a second mounting port 2221 is provided on the rectifier 222.

[0140] Continue to refer to Figure 23 and Figure 24 As shown, the control component 20 also includes a fourth heat sink 2304, which is integrated on the control box 24, so that the control box 24 has both installation and heat dissipation functions. The first circuit board 211 and the second circuit board 212 are both located inside the control box 24. The fourth heat sink 2304 includes a plurality of fourth heat dissipation ribs formed in the circumference of the control box 24, and airflow channels are formed between adjacent fourth heat dissipation ribs. It should be noted that the range of included angle α mentioned above also applies to the fourth heat sink 2304.

[0141] Depending on the shape of the control box 24 or the shape of the internal space of the grip 11, the shape of the circuit board can be flexibly adjusted. The circuit board can be set as a rectangular board, a circular board, or other polygonal boards. Of course, it can also be as follows: Figure 24 As shown, the circuit board is a non-circular plate 204 whose sidewalls are enclosed by an arc-shaped surface 203 and a plane 202.

[0142] In one specific embodiment, the circuit board is formed by cutting a non-circular plate 204 three times in a radial direction perpendicular to the circular plate. The cut surfaces are the aforementioned planes 202. The three planes 202 are located in three directions of the circuit board, such as the top, left, and right sides, or the bottom, left, and right sides. Two of the three planes 202 are arranged in parallel and perpendicular to the remaining plane 202. Furthermore, the circuit board also includes three arc-shaped surfaces 203, each arc-shaped surface 203 being disposed between two adjacent planes 202.

[0143] In one specific embodiment, the diameter of the arcuate surface 203 of the non-circular plate 204 is 51 mm; the distance between the two parallel planes 202 is 45 mm; and the distance between the remaining plane 202 and the arcuate surface 203 on its opposite side is 48.5 mm. In another specific embodiment, the diameter of the arcuate surface 203 of the non-circular plate 204 is 51 mm; the distance between the two parallel planes 202 is 45 mm; and the distance between the remaining plane 202 and the arcuate surface 203 on its opposite side is 46.5 mm.

[0144] In a specific embodiment, such as Figure 26 As shown, heat dissipation holes 2111 are provided on the circuit board. The arrangement of the heat dissipation holes 2111 allows for smooth airflow through the circuit board when it is positioned perpendicular to the extension direction of the gripping part 11, thereby ensuring heat dissipation. The shape and number of heat dissipation holes 2111 can be flexibly set according to requirements.

[0145] like Figure 27 As shown, the electromagnetic interference suppression device 30 is used to suppress electromagnetic interference. In some embodiments, the electromagnetic interference suppression device 30 and the control component 20 are separately arranged. By separately arranging the electromagnetic interference suppression device 30 and the control component 20, the space inside the power tool can be fully utilized for their layout, which is beneficial for miniaturization of the power tool. In a specific embodiment, the electromagnetic interference suppression device 30 is located behind the control component 20 in the extending direction of the grip 11. Of course, in some other embodiments, the electromagnetic interference suppression device 30 can also be integrated with the control component 20.

[0146] In some embodiments, the minimum distance between the electromagnetic interference suppression device 30 and the control component 20 is greater than or equal to 10 mm. In one embodiment, the minimum distance between the electromagnetic interference suppression device 30 and the control component 20 is 9 mm; in another embodiment, the minimum distance between the electromagnetic interference suppression device 30 and the control component 20 is 8 mm; in yet another embodiment, the minimum distance between the electromagnetic interference suppression device 30 and the control component 20 is 7 mm; and in yet another embodiment, the minimum distance between the electromagnetic interference suppression device 30 and the control component 20 is 6 mm.

[0147] Continue to refer to Figure 27 As shown, the electromagnetic interference suppression device 30 includes an electromagnetic interference suppression circuit board 31, a first capacitor 32, a resistor 33, and an inductor 34, all of which are integrated on the electromagnetic interference suppression circuit board 31.

[0148] In some embodiments, the electromagnetic interference suppression circuit board 31 is configured as a single-board structure. Of course, in other embodiments, the electromagnetic interference suppression circuit board 31 can also be configured as a multi-board structure as needed. In some embodiments, the electromagnetic interference suppression circuit board 31 is disposed in a direction parallel to the extension direction of the grip portion 11; in some parallel embodiments, the electromagnetic interference suppression circuit board 31 is disposed at an angle relative to the extension direction of the grip portion 11.

[0149] In some embodiments, the maximum length of the electromagnetic interference suppression circuit board 31 is less than 65 mm. In one embodiment, the maximum length of the electromagnetic interference suppression circuit board 31 is 60 mm; in another embodiment, the maximum length of the electromagnetic interference suppression circuit board 31 is 58 mm; in yet another embodiment, the maximum length of the electromagnetic interference suppression circuit board 31 is 55 mm; in one embodiment, the maximum length of the electromagnetic interference suppression circuit board 31 is 52 mm; and in yet another embodiment, the maximum length of the electromagnetic interference suppression circuit board 31 is 40 mm.

[0150] In some parallel embodiments, the maximum length of the electromagnetic interference resistant circuit board 31 is less than 55 mm.

[0151] In some parallel embodiments, the maximum length of the electromagnetic interference resistant circuit board 31 is less than 45 mm.

[0152] In some embodiments, the area of ​​the electromagnetic interference suppression circuit board 31 is less than or equal to 1500 square millimeters. In one embodiment, the area of ​​the electromagnetic interference suppression circuit board 31 is 1400 square millimeters; in another embodiment, the area of ​​the electromagnetic interference suppression circuit board 31 is 1300 square millimeters; in yet another embodiment, the area of ​​the electromagnetic interference suppression circuit board 31 is 1200 square millimeters; in one embodiment, the area of ​​the electromagnetic interference suppression circuit board 31 is 1100 square millimeters; and in yet another embodiment, the area of ​​the electromagnetic interference suppression circuit board 31 is 1000 square millimeters.

[0153] In some embodiments, resistor 33 is a power NTC resistor and inductor 34 is a common-mode inductor.

[0154] Furthermore, in some embodiments, the electromagnetic interference suppression device 30 further includes a mounting box, and the electromagnetic interference suppression circuit board 31, the first capacitor 32, the resistor 33, and the inductor 34 are all disposed within the mounting box 36. In one embodiment, the mounting box 36 is a rectangular box, and the inner wall surface of the gripping part 11 includes at least a mounting plane, and the mounting box 36 is fixed on the mounting plane.

[0155] It should be noted that if the control component 20 includes the control box 24 and the electromagnetic interference suppression device 30 includes the mounting box 36, then the minimum distance between the electromagnetic interference suppression device 30 and the control component 20 refers to the minimum distance between the control box 24 and the mounting box 36. If the control component 20 does not include the control box 24 or the electromagnetic interference suppression device 30 does not include the mounting box 36, then the minimum distance is calculated based on the boundary of the circuit board in the circuit board assembly 21 or the electromagnetic interference suppression circuit board 31, rather than based on the specific circuit elements on the circuit board.

[0156] In one embodiment, the minimum distance between the circuit board assembly 21 and the electromagnetic interference suppression circuit board 31 is greater than or equal to 5 mm. In another embodiment, the minimum distance between the circuit board assembly 21 and the electromagnetic interference suppression circuit board 31 is greater than or equal to 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, or 45 mm. The minimum distance between the circuit board assembly 21 and the electromagnetic interference suppression circuit board 31 can be 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, or 45 mm.

[0157] In some embodiments, continue to refer to Figure 27 As shown, the electromagnetic interference suppression device 30 also includes an AC power socket 35, which is mounted on the electromagnetic interference suppression circuit board 31. The electromagnetic interference suppression device 30 is located near the rear end of the housing 10, and the power cord 17 passes through the rear end of the housing 10 and can be directly connected to the AC power socket 35.

[0158] like Figure 21As shown, the speed controller 40 is used to adjust the rotational speed of the brushless motor 14. In some embodiments, the speed controller 40 and the control assembly 20 at least partially overlap along the extension direction of the grip 11. This arrangement makes the internal structure of the power tool compact, which is beneficial for miniaturization of the power tool.

[0159] Continue to refer to Figure 21 and Figure 28 As shown, the power tool also includes a motor switch 18 for user operation to control the start and stop of the brushless motor 14. The motor switch 18 is retractably mounted below the grip 11, and the brushless motor 14 can be powered on and off by pressing the motor switch 18.

[0160] In some embodiments, the motor switch 18 is disposed between the electromagnetic interference suppression device 30 and the control component 20. In some embodiments, the speed controller 40 is located between the motor switch 18 and the brushless motor 14.

[0161] like Figure 21 As shown, the overall layout of the power tool from back to front is as follows: power cord 17 → electromagnetic interference suppression device 30 → motor switch 18 → speed controller 40 → control component 20 → brushless motor 14 → transmission mechanism 15 → output shaft 12 and working accessories 13.

[0162] The brushless motor 14, control components 20, and electromagnetic interference suppression devices 30 generate a lot of heat during operation. To improve the heat dissipation of the power tool, multiple ventilation openings are provided on the housing 10, so that air can form an airflow inside and outside the power tool under the action of the fan, thereby improving the heat dissipation effect.

[0163] In one embodiment, such as Figure 29 and Figure 30 As shown, the housing 10 has a first air vent 104 located in front of the brushless motor 14, a second air vent 105 located at the control component 20, and a third air vent 106 located at the rear of the grip portion 11. Under the action of the fan 16, a cooling airflow is formed, flowing in from the first air vent 104 and flowing out from the second air vent 105 and the third air vent 106. Since the fan 16 is located between the brushless motor 14 and the control component 20, air is drawn in from the front of the brushless motor 14 and exited from the rear of the control component 20 and the rear of the grip portion 11. The fan 16 draws air to cool the circuit board of the control component 20 and the brushless motor 14.

[0164] In one embodiment, such as Figure 29 and Figure 31As shown, the housing 10 has a first air vent 104 located in front of the brushless motor 14, a second air vent 105 located at the control component 20, a third air vent 106 located at the rear end of the grip portion 11, and at least one fourth air vent 107 radially opposite the fan 16. Under the action of the fan 16, a cooling airflow is formed that flows in from the first air vent 104, the second air vent 105, and the third air vent 106 and flows out from the fourth air vent 107. Since the fan 16 is located between the brushless motor 14 and the control component 20, air is introduced from three points: in front of the brushless motor 14, behind the control component 20, and at the rear end of the grip portion 11. Air is then discharged radially from the fan 16. The suction from the left and right sides of the fan 16 enables efficient cooling of the circuit board of the control component 20 and the brushless motor 14.

[0165] In one specific embodiment, multiple fourth air vents 107 are provided, and the multiple fourth air vents 107 are arranged around the circumference of the housing 10, thereby achieving multiple air outlets and further improving the heat dissipation effect.

[0166] In one specific embodiment, the air intake direction of the third air vent 106 can be flexibly set according to requirements. For example, the air intake direction of the third air vent 106 can be parallel to the central axis of the grip portion 11 or perpendicular to the central axis of the grip portion 11; of course, the air intake direction of the third air vent 106 can be at other angles to the central axis of the grip portion 11. In addition, multiple third air vents 106 are provided, with one third air vent 106 having an air intake direction parallel to the central axis of the grip portion 11, and another third air vent 106 having an air intake direction perpendicular to the central axis of the grip portion 11.

[0167] The length of the AC polishing machine using the brushless motor 14 in the front-to-back direction is limited by the technical solution described in this application. (Continue referring to...) Figure 9 As shown, the distance from the tail of the housing 10 to the center line of the output shaft 12 is a first length L3, which is less than or equal to 450 mm. In some embodiments, the first length L3 is less than or equal to 430 mm. In some embodiments, the first length L3 is less than or equal to 410 mm. In some embodiments, the first length L3 is less than or equal to 400 mm. In some embodiments, the first length L3 is less than or equal to 390 mm. In some embodiments, the first length L3 is less than or equal to 380 mm. It should be noted that the first length L3 refers to the distance excluding the eccentricity of the output shaft 12. The output shaft 12 can be equipped with an eccentric block with an eccentric structure, and then the polishing disc can be installed. That is to say, the first length L3 here does not include the eccentricity.

[0168] Continue to refer to Figure 9As shown, the distance from the tail of the housing 10 to the front end of the stator 142 is the second length L4, and the first length L4 is less than or equal to 280 mm. In one embodiment, the second length L4 is 279 mm; in another embodiment, the second length L4 is 275 mm; and in yet another embodiment, the second length L4 is 270 mm.

[0169] Continue to refer to Figure 9 As shown, the distance from the tail end to the head end of the housing 10 is the overall length L5 of the power tool, and the overall length L5 of the power tool is less than or equal to 450 mm. In one embodiment, the overall length L5 of the power tool is 446 mm; in another embodiment, the overall length L5 of the power tool is 440 mm; in yet another embodiment, the overall length L5 of the power tool is 420 mm; and in yet another embodiment, the overall length L5 of the power tool is 400 mm.

[0170] Continue to refer to Figure 3 As shown, the maximum height of the power tool at the motor switch 18 is the first height D3, which is less than or equal to 63mm. The height of the power tool housing 10 at the motor switch 18 is the second height D4, which is less than or equal to 52mm. It should be noted that the first height D3 can be understood as the sum of the second height D4 and the height of the motor switch 18 protruding from the housing 10.

[0171] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that the above embodiments do not limit this application in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of this application.

Claims

1. An AC polishing machine, comprising: The output shaft is used to drive the movement of the working attachments; A housing that forms a gripping part for a user to hold; Control components, including circuit board assemblies and circuit elements; Electromagnetic interference suppression devices are used to suppress electromagnetic interference. Its characteristic is that it further includes: A brushless motor, having or connected to a motor shaft, wherein the nominal power of the entire brushless motor is greater than 500W and less than 2500W; A transmission mechanism is disposed between the motor shaft and the output shaft to realize transmission; The distance from the tail of the housing to the center line of the output shaft is a first length L3, and the first length L3 is less than or equal to 450mm.

2. The AC polishing machine according to claim 1, wherein, The circuit board assembly includes at least a first circuit board and a second circuit board, which, when viewed from a direction perpendicular to the first circuit board, at least partially overlap.

3. The AC polishing machine according to claim 1, wherein, The circuit board assembly includes at least a first circuit board and a second circuit board. When viewed from a direction perpendicular to the first circuit board, the first circuit board and the second circuit board at least partially overlap. The area of ​​the first circuit board is greater than or equal to the area of ​​the second circuit board, and the maximum length L of the control component along the extension direction of the control component is less than or equal to 75 mm.

4. The AC polishing machine according to claim 2 or 3, wherein, The working attachment is used to clamp the polishing disc; the projected area of ​​the first circuit board on the polishing plane of the polishing disc is less than or equal to 3000 square millimeters; the projected area of ​​the second circuit board on the polishing plane of the polishing disc is less than or equal to 2500 square millimeters.

5. The AC polishing machine according to claim 1, wherein, The electromagnetic interference suppression device includes an electromagnetic interference suppression circuit board, which is configured as a single-board structure.

6. The AC polishing machine according to claim 5, wherein, The maximum length of the electromagnetic interference suppression circuit board is less than 65mm; Alternatively, the maximum length of the electromagnetic interference resistant circuit board is less than 55mm; Alternatively, the maximum length of the electromagnetic interference resistant circuit board is less than 45mm.

7. The AC polishing machine according to claim 5, wherein, The area of ​​the electromagnetic interference-resistant circuit board is less than or equal to 1500 planar millimeters.

8. The AC polishing machine according to claim 1, wherein, The AC polishing machine also includes a fan, which is mounted on the motor shaft and located between the brushless motor and the control component.

9. The AC polishing machine according to claim 8, wherein, The housing has a first air vent located in front of the brushless motor, a second air vent located at the control component, and a third air vent located at the rear of the grip. Under the action of the fan, a cooling airflow is formed that flows in from the first air vent and flows out from the second and third air vents.

10. The AC polishing machine according to claim 8, wherein, The housing has a first air vent located in front of the brushless motor, a second air vent located at the control component, a third air vent located at the rear end of the grip, and at least one fourth air vent radially opposite the fan. Under the action of the fan, a cooling airflow is formed that flows in from the first air vent, the second air vent, and the third air vent, and flows out from the fourth air vent.

11. The AC polishing machine according to claim 1, wherein, The brushless motor includes a first bearing supported at the front end of the motor shaft, the first bearing at least partially overlapping the stator of the brushless motor in the axial direction of the motor shaft.

12. The AC polishing machine according to claim 8, wherein, The brushless motor includes a second bearing supported at the rear end of the motor shaft, the second bearing at least partially overlapping the fan in the axial direction of the motor shaft.

13. The AC polishing machine according to claim 1, wherein, The control component includes a circuit board assembly, and the plane on which the circuit board assembly is located is set at an angle to the axis of the motor shaft.

14. The AC polishing machine according to claim 13, wherein, The plane containing the circuit board assembly is substantially perpendicular to the axis of the motor shaft.

15. The AC polishing machine according to claim 13, wherein, The circuit board assembly includes at least one circuit board, which is a non-circular plate with sidewalls formed by arcuate surfaces and planes.

16. The AC polishing machine according to claim 13, wherein, The circuit board assembly includes multiple circuit boards, all of which are perpendicular to the axial direction of the motor shaft.

17. The AC polishing machine according to claim 1, wherein, The circumference D1 of the grip portion along the midline is less than 135mm.

18. The AC polishing machine according to claim 1, wherein, The perimeter D2 of the motor housing at the stator cleavage of the brushless motor is less than or equal to 235 mm.

19. The AC polishing machine according to claim 1, wherein, The power of the brushless motor is greater than or equal to 1000W and less than or equal to 2000W.

20. The AC polishing machine according to claim 1, wherein, The stack length of the brushless motor is greater than or equal to 10mm and less than or equal to 50mm, and the outer diameter of the brushless motor is greater than or equal to 30mm and less than or equal to 65mm.

Images