Alternating-current polishing machine

Abstract

An alternating-current polishing machine. The alternating-current polishing machine comprises an output shaft (12), a brushless electric motor (14), a transmission mechanism (15), a housing (10), a control assembly (20) and an anti-electromagnetic interference device (30), wherein the output shaft (12) is configured to drive a working accessory (13) to move; the brushless electric motor (14) is provided with or connected to an electric motor shaft (141); the transmission mechanism (15) is configured to realize transmission between the electric motor shaft (141) and the output shaft (12); the housing (10) forms a holding portion (11) for a user to hold; the control assembly (20) comprises a circuit board assembly (21) and a circuit element (22); and the anti-electromagnetic interference device (30) is configured to suppress electromagnetic interference. Moreover, nominal power of the entire brushless electric motor (14) is greater than 500 W and less than 2500 W. The distance from the tail of the housing (10) to a center line of the output shaft (12) is a first length L3, the first length L3 being less than or equal to 450 mm.

Description

AC polishing machine

[0001] This application claims the priority of the Chinese patent application with application number 202410312864.0 filed with the China Patent Office on March 19, 2024, claims the priority of the Chinese patent application with application number 202420531964.8 filed with the China Patent Office on March 19, 2024, claims the priority of the Chinese patent application with application number 202420546267.X filed with the China Patent Office on March 19, 2024, claims the priority of the Chinese patent application with application number 202420546267.X filed with the China Patent Office on March 19, 2024, The application claims priority to the Chinese patent application with application number 202420539604.2 filed with the China Patent Office on March 19, 2024, and claims priority to the Chinese patent application with application number 202420532195.3 filed with the China Patent Office on March 19, 2024, and claims priority to the Chinese patent application with application number 202420532252.8 filed with the China Patent Office on March 19, 2024. All the contents of the above applications are incorporated into this application by reference. Technical Field

[0002] The present application relates to an electric tool, for example, an AC polishing machine. Background Art

[0003] A polishing machine, as used in related art, is a grinding tool that uses a motor to drive a polishing disc to rotate at high speed, causing the disc to polish the surface of a workpiece. Also known as a grinder, a polishing machine is commonly used for mechanical grinding, polishing, and waxing. The polishing disc, which can be a sponge or wool polishing disc, rubs the surface to be polished with the polishing compound, thereby removing paint contamination, oxide layers, and shallow scratches.

[0004] Polishing machines require motors to provide power. Conventional polishing machines are becoming larger and larger in size due to the pursuit of high motor power, which makes it difficult for users to hold the polishing machine and operate it.

[0005] This section provides background information related to the present application which is not necessarily prior art. Summary of the Invention

[0006] One object of the present application is to solve or at least alleviate part or all of the above problems. To this end, one object of the present application is to provide an AC polishing machine with a smaller size, so that the AC polishing machine is miniaturized.

[0007] In order to achieve the above objectives, this application adopts the following technical solutions:

[0008] An AC polishing machine comprises: an output shaft configured to drive a working accessory to move; a brushless motor provided with or connected to a motor shaft; a transmission mechanism configured to implement transmission between the motor shaft and the output shaft; a housing forming a grip for a user to hold; a control assembly comprising a circuit board assembly and circuit elements; an anti-electromagnetic interference device configured to suppress electromagnetic interference; the nominal power of the brushless motor as a whole 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.

[0009] In some embodiments, the circuit board assembly includes at least a first circuit board and a second circuit board, and when viewed from a direction perpendicular to the first circuit board, the first circuit board and the second circuit board at least partially overlap.

[0010] In some embodiments, the circuit board assembly includes at least a first circuit board and a second circuit board. When viewed in 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 assembly along the extension direction of the control assembly is less than or equal to 75 mm.

[0011] In some embodiments, the working accessory is configured to clamp a polishing disk, and the projection area of ​​the first circuit board on the polishing plane of the polishing disk is less than or equal to 3000 square millimeters; and / or, the projection area of ​​the second circuit board on the polishing plane of the polishing disk is less than or equal to 2500 square millimeters.

[0012] In some embodiments, the anti-electromagnetic interference device includes an anti-electromagnetic interference circuit board, and the anti-electromagnetic interference circuit board is configured as a single-board structure.

[0013] In some embodiments, the maximum length of the anti-electromagnetic interference circuit board is less than 65 mm; or, the maximum length of the anti-electromagnetic interference circuit board is less than 55 mm; or, the maximum length of the anti-electromagnetic interference circuit board is less than 45 mm.

[0014] In some embodiments, the area of ​​the anti-electromagnetic interference circuit board is less than or equal to 1500 planar millimeters.

[0015] In some embodiments, the AC polishing machine further includes a fan, which is sleeved on the motor shaft and located between the brushless motor and the control component.

[0016] In some embodiments, the housing is formed with a first air outlet located in front of the brushless motor, a second air outlet located at the control component, and a third air outlet located at the rear end of the grip portion. Under the action of the fan, a heat dissipation airflow is formed flowing in from the first air outlet and flowing out from the second air outlet and the third air outlet.

[0017] In some embodiments, the housing is formed with a first air outlet located in front of the brushless motor, a second air outlet located at the control component, a third air outlet located at the rear end of the grip portion, and at least one fourth air outlet radially opposite to the fan. Under the action of the fan, a heat dissipation airflow is formed flowing in from the first air outlet, the second air outlet, and the third air outlet and flowing out from the fourth air outlet.

[0018] In some embodiments, the brushless motor includes a first bearing supported at a front end of the motor shaft, and the first bearing at least partially overlaps with a stator of the brushless motor in an axial direction of the motor shaft.

[0019] In some embodiments, the brushless motor includes a second bearing supported at a rear end of the motor shaft, and the second bearing at least partially overlaps with the fan in an axial direction of the motor shaft.

[0020] In some embodiments, the control assembly includes a circuit board assembly, and a plane where the circuit board assembly is located is arranged at an angle to the axis of the motor shaft.

[0021] In some embodiments, the plane where the circuit board assembly is located is substantially perpendicular to the axis of the motor shaft.

[0022] In some embodiments, the circuit board assembly includes at least one circuit board, and the circuit board is a non-circular plate having a side wall formed by an arc surface and a flat surface.

[0023] In some embodiments, the circuit board assembly includes a plurality of circuit boards, and the plurality of circuit boards are all perpendicular to the axial direction of the motor shaft.

[0024] In some embodiments, the circumference D1 of the grip portion along the midline is less than 135 mm.

[0025] In some embodiments, a circumference D2 of the motor housing of the brushless motor at a mid-stator dividing line is less than or equal to 235 mm.

[0026] In some embodiments, the power of the brushless motor is greater than or equal to 1000W and less than or equal to 2000W.

[0027] In some embodiments, a stack length of the brushless motor is greater than or equal to 10 mm and less than or equal to 50 mm.

[0028] 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.

[0029] The benefits of this application are:

[0030] The AC polishing machine provided in this application includes an output shaft, a brushless motor, a transmission mechanism, a housing, a control assembly, and an anti-electromagnetic interference device. The output shaft is configured to drive a working accessory, the brushless motor is provided with or connected to a motor shaft, the transmission mechanism is configured to transmit power between the motor shaft and the output shaft, the housing forms a grip for a user to hold, the control assembly includes a circuit board assembly and circuit elements, and the anti-electromagnetic interference device is configured to suppress electromagnetic interference. Furthermore, the nominal power of the brushless motor is greater than 500W and less than 2500W; the distance from the rear end of the housing to the centerline of the output shaft is a first length L3, and the first length L3 is less than or equal to 390mm. This configuration of the AC polishing machine ensures that the brushless motor is not excessively large and the overall length of the housing is short, thereby facilitating miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG1 is a schematic diagram of an electric tool;

[0032] FIG2 is an exploded view of the power tool in FIG1 ;

[0033] FIG3 is a front view of the power tool in FIG1 after the working accessories are removed;

[0034] FIG4 is a schematic diagram of the brushless motor, transmission mechanism and output shaft in FIG1 at a certain viewing angle;

[0035] FIG5 is a schematic diagram of the structure shown in FIG4 from another perspective;

[0036] FIG6 is a cross-sectional view of the structure shown in FIG4;

[0037] FIG7 is a cross-sectional view of the brushless motor in FIG1 ;

[0038] FIG8 is an exploded view of the first control assembly;

[0039] FIG9 is a schematic diagram of the dimensions of the power tool in FIG1 ;

[0040] FIG10 is a schematic diagram showing the dimensions of a circuit board of a first control assembly;

[0041] FIG11 is a layout diagram of circuit elements of the first control assembly in FIG10;

[0042] FIG12 is a schematic diagram of a partial structure of the first control assembly in FIG10;

[0043] FIG13 is a schematic diagram of the structure shown in FIG12 from another perspective;

[0044] FIG14 is a schematic diagram of the structure shown in FIG12 with the control box removed;

[0045] FIG15 is a schematic diagram of a radiator of the first control assembly in FIG10;

[0046] FIG16 is an exploded view of another power tool;

[0047] FIG17 is a schematic diagram of a second control assembly;

[0048] FIG18 is a schematic diagram of the structure shown in FIG17 with the control box removed;

[0049] FIG19 is an exploded view of the structure shown in FIG18;

[0050] FIG20 is a cross-sectional view of the structure shown in FIG18;

[0051] FIG21 is an exploded view of another power tool;

[0052] FIG22 is a schematic diagram of a third control assembly;

[0053] FIG23 is an exploded view of the structure shown in FIG22;

[0054] FIG24 is a schematic diagram of the structure shown in FIG23 from another perspective;

[0055] FIG25 is a layout diagram of circuit elements of a third control assembly;

[0056] FIG26 is a schematic diagram of a third control component with heat dissipation holes formed on a circuit board;

[0057] FIG27 is a schematic diagram of an anti-electromagnetic interference device;

[0058] Figure 28 is a schematic diagram of the position of the motor switch;

[0059] FIG29 is a schematic diagram of a vent on a power tool;

[0060] FIG30 is a schematic diagram of a first flow path of heat dissipation airflow of a power tool;

[0061] FIG31 is a schematic diagram of a second flow path of the heat dissipation airflow of the power tool;

[0062] FIG32 is a schematic diagram of another power tool;

[0063] FIG33 is a schematic diagram of the power tool in FIG32 after the second housing is removed;

[0064] FIG34 is a schematic diagram of a partial structure of a control assembly;

[0065] FIG35 is a schematic diagram of part A in FIG33;

[0066] FIG36 is a schematic diagram of a first heat sink dissipating heat to an electronic switch and a rectifier simultaneously;

[0067] FIG37 is a schematic diagram of a first heat sink, an electronic switch, a rectifier, and a plastic encapsulation layer;

[0068] FIG38 is a schematic diagram of the structure shown in FIG37 from another perspective;

[0069] FIG39 is a cross-sectional view of the structure shown in FIG37;

[0070] FIG40 is a schematic diagram of a first heat sink, an electronic switch, and a rectifier;

[0071] FIG41 is an exploded view of the second housing and the dust cover;

[0072] Figure 42 is a schematic diagram of a dust cover;

[0073] FIG43 is a cross-sectional view of the structure shown in FIG41. DETAILED DESCRIPTION

[0074] Before any embodiments of the present application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the foregoing drawings.

[0075] In this application, the terms "comprises," "includes," "has," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0076] In this application, the term "and / or" describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Additionally, the character " / " in this application generally indicates that the related objects are in an "and / or" relationship.

[0077] In this application, the terms "connect," "combine," "couple," and "install" may 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 an intermediary, and an indirect connection refers to two parts or components being connected to at least one intermediary, with the two parts or components being connected via the intermediary. Furthermore, "connect" and "couple" are not limited to physical or mechanical connections or couplings and may include electrical connections or couplings.

[0078] In this application, it will be understood by those skilled in the art that relative terms (e.g., "about," "approximately," "substantially," etc.) used in conjunction with quantities or conditions include the values ​​and have the meaning indicated by the context. For example, the relative terms include at least the degree of error associated with the measurement of a specific value, the tolerance caused by manufacturing, assembly, use, etc. associated with a specific value. Such terms should also be considered to disclose a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to plus or minus a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​that do not use relative terms should also be disclosed as specific values ​​with tolerances. In addition, "substantially" may refer to plus or minus a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) on the basis of the indicated angle when expressing a relative angular position relationship (e.g., substantially parallel, substantially perpendicular).

[0079] In this application, it will be understood by those skilled in the art that the function performed by an assembly can be performed by one assembly, multiple assemblies, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one assembly, or a combination of multiple parts.

[0080] In the present application, the terms "upper", "lower", "left", "right", "front", "back" and other directional words are described based on the orientation and positional relationship shown in the accompanying drawings, and should not be understood as limiting the embodiments of the present application. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to the other element "upper" or "lower", but also be indirectly connected to the other element "upper" or "lower" through an intermediate element. It should also be understood that directional words such as upper side, lower side, left side, right side, front side, back side, etc. not only represent the positive orientation, but can also be understood as the lateral orientation. For example, below can include directly below, lower left, lower right, lower front and lower back, etc.

[0081] In this application, the terms "controller," "processor," "central processing unit," "CPU," and "MCU" are used interchangeably. Where a unit "controller," "processor," "central processing unit," "CPU," or "MCU" is used to perform a particular function, unless otherwise specified, the function may be performed by a single unit or multiple units.

[0082] In this application, the terms "device", "module" or "unit" can be implemented in the form of hardware or software to achieve specific functions.

[0083] In this application, the terms "calculate", "judge", "control", "determine", "identify", etc. refer to the operations and processes of a computer system or similar electronic computing device (e.g., controller, processor, etc.).

[0084] The present application provides an electric tool. In some embodiments, the electric tool may be an AC polisher. Of course, in other embodiments, the electric tool can be replaced with operating accessories as needed to enable the electric tool to be used to perform other operations, such as an impact drill, an electric screwdriver, etc.

[0085] As shown in FIG. 1 to FIG. 6 , the electric tool includes a housing 10 , a brushless motor 14 , a transmission mechanism 15 , an output shaft 12 , a working accessory 13 , a fan 16 , a control assembly 20 , an anti-electromagnetic interference device 30 and a speed regulator 40 .

[0086] The housing 10 is the main installation component and protective component of the power tool. The housing 10 can be an integral part or formed by connecting multiple parts. As shown in Figure 2, the housing 10 includes a first shell 101, a second shell 102 and a third shell 103. Among them, the first shell 101 and the second shell 102 are both half shells. The first shell 101 and the second shell 102 are spliced ​​together to form the rear shell of the housing 10. The control component 20, the anti-electromagnetic interference device 30 and the speed regulator 40 are all installed in the rear shell. The rear part of the rear shell forms a through hole for the power cord 17 to extend into. The third shell 103 is the front shell of the power tool. The third shell 103 can be formed by splicing two half shells or an integral part. The transmission mechanism 15 and the top of the output shaft 12 are placed in the third shell 103, and the lower part of the third shell 103 forms a through hole for the output shaft 12 to extend out.

[0087] The housing 10 partially forms a grip 11 for a user to grasp to operate the power tool. In some embodiments, the rear housing portion serves as the grip 11. An anti-slip structure is provided on the grip 11 to enhance the user's grip stability. The anti-slip structure may be a non-slip rubber sleeve, anti-slip texture, or the like.

[0088] In some embodiments, as shown in FIG3 , 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 one embodiment, the circumference D1 of the grip portion 11 along the midline is 130 mm; in one 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 one embodiment, the circumference D1 of the grip portion 11 along the midline is 115 mm.

[0089] The brushless motor 14 is placed in the housing 10. Specifically, the brushless motor 14 can be placed in 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.

[0090] In addition to a motor housing 144, the brushless motor 14 also includes a stator 142, a rotor 143, and a bearing assembly 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. The first bearing 145 and the stator 142 of the brushless motor 14 at least partially overlap along the axis of the motor shaft 141. This arrangement improves the compactness of the power tool's interior and facilitates miniaturization.

[0091] In some specific embodiments, the present application moves the bearing locating structure that secures the first bearing 145 15 mm inward of the motor housing 144 to the inside of the stator 142. In other embodiments, the distance of this movement can be adjusted as needed. The bearing locating structure can be a bearing seat or a locating groove.

[0092] 5 and 6 , the fan 16 is sleeved 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 sleeved on the rear end of the motor shaft 141 of the brushless motor 14. 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 and the fan 16 at least partially overlap in the axial direction of the motor shaft 141.

[0093] In some specific embodiments, the present application moves the bearing locator 147 that secures the second bearing 146 14.5 mm inward of the motor housing 144 to the inner recess of the fan 16. In other embodiments, the distance of this movement can be adjusted as needed. The bearing locator 147 can be a bearing seat or a locating groove.

[0094] As shown in FIG7 , in some embodiments, a noise-reducing metal ring 148 is further provided around the stator 142. The noise-reducing metal ring 148 is in close contact with the outer wall of the stator 142, thereby reducing vibration of the stator 142 and achieving a noise reduction effect. In some embodiments, multiple noise-reducing metal rings 148 are provided, and the multiple noise-reducing metal rings 148 are spaced apart along the motor shaft 141 of the brushless motor 14.

[0095] In some embodiments, the power of the brushless motor 14 is greater than or equal to 1000 W and less than or equal to 2000 W. In the embodiment of the present application, the rated power of the brushless motor 14 is 1400 W.

[0096] 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 one embodiment, the stack length of the brushless motor 14 is 25 mm; in one embodiment, the stack length of the brushless motor 14 is 35 mm; in one embodiment, the stack length of the brushless motor 14 is 35 mm; and in one embodiment, the stack length of the brushless motor 14 is 45 mm.

[0097] 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 one embodiment, the outer diameter of the brushless motor 14 is 40 mm; in one embodiment, the outer diameter of the brushless motor 14 is 50 mm; and in one embodiment, the outer diameter of the brushless motor 14 is 60 mm.

[0098] 3 , in some embodiments, the circumference D2 of the motor housing 144 of the brushless motor 14 at the bisection line in the stator 142 is less than or equal to 235 mm. In one embodiment, the circumference D2 of the motor housing 144 of the brushless motor 14 at the bisection line in the stator 142 is 230 mm; in one embodiment, the circumference D2 of the motor housing 144 of the brushless motor 14 at the bisection line in the stator 142 is 225 mm; in one embodiment, the circumference D2 of the motor housing 144 of the brushless motor 14 at the bisection line in the stator 142 is 222 mm; in one embodiment, the circumference D2 of the motor housing 144 of the brushless motor 14 at the bisection line in the stator 142 is 219 mm; in one embodiment, the circumference D2 of the motor housing 144 of the brushless motor 14 at the bisection line in the stator 142 is 215 mm; and in one embodiment, the circumference D2 of the motor housing 144 of the brushless motor 14 at the bisection line in the stator 142 is 210 mm.

[0099] In some embodiments, the nominal power of the entire brushless motor 14 is greater than 500W and less than 2500W. It should be noted that the nominal power is the entire power of the power tool, specifically the entire power of an AC polishing machine. For an AC polishing machine, the nominal power refers to the power value indicated on the machine nameplate, which is also the rated power value of the machine. In one embodiment, the nominal power of the entire brushless motor 14 is 800W; in one embodiment, the nominal power of the entire brushless motor 14 is 1100W; in one embodiment, the nominal power of the entire brushless motor 14 is 1300W; in one embodiment, the nominal power of the entire brushless motor 14 is 1600W; in one embodiment, the nominal power of the entire brushless motor 14 is 1800W.

[0100] In some parallel embodiments, the nominal power of the brushless motor 14 is greater than 1000W and less than 2000W.

[0101] In some parallel embodiments, the nominal power of the brushless motor 14 is greater than 1200W and less than 1500W.

[0102] Continuing with Figures 4 to 6 , the brushless motor 14 is provided with or connected to a motor shaft 141. The transmission mechanism 15 is connected between the motor shaft 141 and the output shaft 12 and is used to transmit power between the motor shaft 141 and the output shaft 12. Compared to conventional polishing machines using series-excited brush motors, which require more complex carbon brush replacement, the present application can effectively solve this problem by using a brushless motor 14.

[0103] When the power tool is in the working state, the motor shaft 141 is basically arranged horizontally, and the output shaft 12 is basically arranged vertically. In order to realize the transmission of power between the motor shaft 141 and the output shaft 12, as shown in Figure 6, 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, and the second reduction shaft 155 is connected to the planetary 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.

[0104] When the motor shaft 141 of the brushless motor 14 rotates, the power is transmitted to the output shaft 12 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 in sequence, so that the output shaft 12 can drive the working accessory 13 to rotate, and the working accessory 13 can clamp the polishing disk to achieve grinding and polishing of the workpiece to be processed.

[0105] As for the polishing pad, it is arranged substantially horizontally, 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 one embodiment, the diameter of the polishing pad is 190 mm; in one embodiment, the diameter of the polishing pad is 200 mm; in one embodiment, the diameter of the polishing pad is 210 mm; in one embodiment, the diameter of the polishing pad is 220 mm; in one embodiment, the diameter of the polishing pad is 230 mm.

[0106] The control assembly 20 is used to control and power the brushless motor 14. Figures 8 to 15 illustrate a first configuration of the control assembly 20; Figures 16 to 20 illustrate a second configuration of the control assembly 20; and Figures 21 to 26 illustrate a third configuration of the control assembly 20. The following describes the specific structure of the control assembly 20. It should be noted that some components of the three configurations described above are common to the control assembly 20; however, they are only shown in the figures for one configuration.

[0107] Specifically, the control assembly 20 includes a circuit board assembly 21, a circuit element 22, and a control box 24. The circuit board assembly 21 and the circuit element 22 are both disposed within the control box 24, and the circuit element 22 is integrated onto the circuit board assembly 21. To secure the circuit board assembly 21 and the circuit element 22 within the control box 24, after the circuit element 22 is mounted on the circuit board assembly 21, the resulting assembly is placed within the control box 24, and a colloid 25 is injected into the control box 24 to secure the circuit board assembly 21 and the circuit element 22 within the control box 24. Furthermore, injecting the colloid 25 into the control box 24 can also provide a certain degree of waterproofing and dustproofing. It should be noted that after the colloid 25 is injected into the control box 24, a portion of the circuit element 22 is still exposed outside the colloid, and this portion requires dustproofing. Therefore, protection is required on the exposed metal of the circuit element 22, such as forming a sealing layer, to prevent failure in the presence of water and dust.

[0108] In some embodiments, the plane where the circuit board assembly 21 is located is arranged at an angle to the axis of the motor shaft 141. In one embodiment, the plane where the circuit board assembly 21 is located is substantially perpendicular to the axis of the motor shaft 141.

[0109] 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, as shown in Figures 8, 18 and 23, the circuit board assembly 21 includes two circuit boards, the two circuit boards being a first circuit board 211 and a second circuit board 212 electrically connected to each other, the first circuit board 211 and the second circuit board 212 being arranged substantially in parallel, and 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 being greater than or equal to the area of ​​the second circuit board 212, and as shown in Figure 9, the maximum length L of the control assembly 20 along the extension direction of the grip portion 11 is less than or equal to 75 mm. By providing two circuit boards, different types of circuit elements 22 can be electrically connected to different circuit boards. Such an arrangement reduces the space occupied by the control assembly 20, which is conducive to the miniaturization of the power tool.

[0110] In some embodiments, as shown in FIG10 , 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 one specific embodiment, the maximum length L1 of the first circuit board 211 is 70 mm; in one specific embodiment, the maximum length L1 of the first circuit board 211 is 67 mm; in one specific embodiment, the maximum length L1 of the first circuit board 211 is 65 mm; and in one specific embodiment, the maximum length L1 of the first circuit board 211 is 60 mm.

[0111] In some embodiments, as shown in FIG10 , 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 one specific embodiment, the maximum length L2 of the second circuit board 212 is 55 mm; in one 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 one specific embodiment, the maximum length L2 of the second circuit board 212 is 48 mm.

[0112] In one embodiment, the length of the first circuit board 211 is 72 mm, and the width W of the first circuit board 211 is 39 mm; the length of the second circuit board 212 is 60 mm, and the width W of the second circuit board 212 is 39 mm.

[0113] In some embodiments, along the extension direction of the grip portion 11, the maximum length of the first circuit board 211 is less than or equal to 75 mm. In some embodiments, along the extension direction of the grip portion 11, the maximum length L2 of the second circuit board 212 is less than or equal to 60 mm. It should be noted that along the extension direction of the grip portion 11, the maximum length of the first circuit board 211 is related to the position of the first circuit board 211 in the grip portion 11. When the first circuit board 211 is parallel to the extension direction of the grip portion 11, the maximum length of the first circuit board 211 along the extension direction of the grip portion 11 is the above-mentioned L1. When the first circuit board 211 is tilted relative to the extension direction of the grip portion 11, the maximum length of the first circuit board 211 along the extension direction of the grip portion 11 is equal to the length of the projection of the first circuit board 211 in the extension direction of the grip portion 11. This 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 holding portion 11. When the second circuit board 212 is parallel to the extension direction of the holding portion 11, the maximum length of the second circuit board 212 along the extension direction of the holding portion 11 is the above-mentioned L2. When the second circuit board 212 is tilted relative to the extension direction of the holding portion 11, the maximum length of the second circuit board 212 along the extension direction of the holding portion 11 is equal to the length of the projection of the second circuit board 212 in the extension direction of the holding portion 11, which is less than L2.

[0114] In some embodiments, the area of ​​the first circuit board 211 is less than or equal to 3000 square millimeters. In a specific embodiment, the area of ​​the first circuit board 211 is 2900 square millimeters; in a specific embodiment, the area of ​​the first circuit board 211 is 2800 square millimeters; in a specific embodiment, the area of ​​the first circuit board 211 is 2700 square millimeters; in a specific embodiment, the area of ​​the first circuit board 211 is 2600 square millimeters; in a specific embodiment, the area of ​​the first circuit board 211 is 2500 square millimeters; in a specific embodiment, the area of ​​the first circuit board 211 is 2400 square millimeters; in a specific embodiment, the area of ​​the first circuit board 211 is 2300 square millimeters; in a specific embodiment, the area of ​​the first circuit board 211 is 2200 square millimeters; in a specific embodiment, the area of ​​the first circuit board 211 is 2100 square millimeters; in a specific embodiment, the area of ​​the first circuit board 211 is 2000 square millimeters.

[0115] In some embodiments, the area of ​​the second circuit board 212 is less than or equal to 2500 square millimeters. In a specific embodiment, the area of ​​the second circuit board 212 is 2400 square millimeters; in a specific embodiment, the area of ​​the second circuit board 212 is 2300 square millimeters; in a specific embodiment, the area of ​​the second circuit board 212 is 2200 square millimeters; and in a specific embodiment, the area of ​​the second circuit board 212 is 2100 square millimeters.

[0116] In some embodiments, the projected area of ​​the first circuit board 211 on the polishing plane 202 of the polishing plate is less than or equal to 3000 square millimeters.

[0117] In some embodiments, the projected area of ​​the second circuit board 212 on the polishing plane 202 of the polishing plate is less than or equal to 2500 square millimeters.

[0118] In some embodiments, 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 in a direction perpendicular to the first circuit board 211 is the overlap ratio, where the overlap ratio is greater than or equal to 50%. In one specific embodiment, the overlap ratio of the first circuit board 211 and the second circuit board 212 is 49%; in one specific embodiment, the overlap ratio of the first circuit board 211 and the second circuit board 212 is 48%; in one specific embodiment, the overlap ratio of the first circuit board 211 and the second circuit board 212 is 47%; in one specific embodiment, the overlap ratio of the first circuit board 211 and the second circuit board 212 is 46%; and in one specific embodiment, the overlap ratio of the first circuit board 211 and the second circuit board 212 is 45%.

[0119] Furthermore, the number of circuit boards included in the circuit board assembly 21 is not limited to two and can be set to three, four, or more as needed. In some embodiments, the circuit board assembly 21 also includes a third circuit board. When viewed 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 arrangement can further reduce the size of the first circuit board 211 and the second circuit board 212, further facilitating the miniaturization of the power tool.

[0120] When the circuit board assembly 21 includes three circuit boards, the maximum length L1 of the first circuit board 211 can be effectively reduced, such that the maximum length L1 of the first circuit board 211 is 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 one specific embodiment, the maximum length L1 of the first circuit board 211 is 63 mm; in one specific embodiment, the maximum length L1 of the first circuit board 211 is 62 mm; in one specific embodiment, the maximum length L1 of the first circuit board 211 is 61 mm; and in one specific embodiment, the maximum length L1 of the first circuit board 211 is 60 mm.

[0121] In one embodiment, the length of the first circuit board 211 is 61.5 mm, and the width of the first circuit board 211 is 44 mm; the length of the second circuit board 212 is 50 mm, and the width of the second circuit board 212 is 36 mm; the length of the third circuit board is 63 mm, and the width of the third circuit board is 20 mm.

[0122] It should be noted that in order to improve the structural compactness of the control component 20, multiple circuit boards are basically arranged in parallel, and the control component 20 is arranged in the housing 10. In some embodiments, as shown in Figures 8 to 20, when the power tool is in working condition, the circuit board is basically arranged horizontally and parallel to the central axis of the grip 11; in some parallel embodiments, when the power tool is in working condition, as shown in Figures 21 to 26, the circuit board is basically arranged vertically and perpendicular to the central axis of the grip 11; of course, in other embodiments, when the power tool is in working condition, the circuit board can also be arranged at an angle and be arranged at an acute angle or an obtuse angle to the central axis of the grip 11.

[0123] Continuing with reference to Figure 8, 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 the 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 the first circuit board 211, and the control module is set on the second circuit board 212.

[0124] 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. It receives AC power input from the power line 17 and outputs a DC bus voltage. In other words, 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 normal operation of the brushless motor 14. In some embodiments, the control module is implemented using a control chip.

[0125] In some embodiments, the electronic switch 221 is perpendicular to the circuit board. In some embodiments, the electronic switch 221 is an IGBT, which stands for field-effect transistor; in some embodiments, the electronic switch 221 is a MOS; in some embodiments, the electronic switch 221 is a FET, which stands for field-effect transistor.

[0126] In some embodiments, a plurality of electronic switches 221 are regularly arranged on the first circuit board 211, for example, they can be arranged in rows and columns or in a ring. In one embodiment, as shown in Figure 11, the first circuit board 211 is arranged above the second circuit board 212, and six electronic switches 221 are provided. The six electronic switches 221 are distinguished by 221a, 221b, 221c, 221d, 221e, and 221f, and the six electronic switches 221 are arranged in two rows and three columns. The rectifier 222 and the plurality of electronic switches 221 are arranged side by side in the length direction of the first circuit board 211. There are three second capacitors 223, one of which is arranged on one side of the electronic switch 221, and the other two second capacitors 223 are arranged on both sides of the rectifier 222. Continuing with reference to Figure 11, the three second capacitors 223 are distinguished by 223a, 223b, and 223c.

[0127] In some parallel embodiments, as shown in Figures 17 to 19, the first circuit board 211 is arranged below the second circuit board 212, the number and arrangement of the electronic switches 221 and the rectifiers 222 remain unchanged, the number of the second capacitors 223 is adjusted to six, and they are arranged on the second circuit board 212, and the six second capacitors 223 are arranged in a row.

[0128] In some parallel embodiments, as shown in Figures 21 to 25, the number of electronic switches 221, rectifiers 222, and second capacitors 223 remains unchanged, but their arrangement is adjusted: six electronic switches 221 are arranged in two rows and three columns, three second capacitors 223 are disposed between the two rows of electronic switches 221, and the rectifier 222 is disposed 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 based on needs and the internal space of the grip 11.

[0129] 8 , 18 and 22 , the electric tool further includes a radiator 23 , which is used to dissipate heat for the control assembly 20 . The number of the radiators 23 can be one or more as required.

[0130] In some embodiments, with continued reference to Figures 12 to 15 , when the power tool is in operation, the circuit boards are substantially horizontally arranged, and the power tool is provided with a heat sink 23. The heat sink 23 is located below the first circuit board 211, and the heat sink 23 contacts the surfaces of the plurality of electronic switches 221 and the rectifier 222. The first pin of the electronic switch 221 and the second pin of the rectifier 222 are welded to the back side of the circuit board. The heat sink 23 can dissipate heat for the electronic switch 221 and the rectifier 222 to avoid malfunctions caused by overheating. Of course, in other embodiments, the positions of the first circuit board 211 and the second circuit board 212 can also be adjusted so that the first circuit board 211 is located above the second circuit board 212, and the heat sink 23 is located above the first circuit board 211.

[0131] Continuing with reference to FIG15 , the heat sink 23 includes a first heat dissipation portion 232 and a second heat dissipation portion 233 vertically connected. The first heat dissipation portion 232 is basically horizontally arranged and is arranged above a plurality of electronic switches 221 and a rectifier 222. A plurality of air flow channels that are basically parallel to the first circuit board 211 are formed on the first heat dissipation portion 232. The second heat dissipation portion 233 is inserted between the two rows of electronic switches 221 and is in contact with both the two rows of electronic switches 221 and the rectifier 222. Such an arrangement can improve the heat dissipation effect and efficiency.

[0132] Continuing with FIG8 and FIG15 , to achieve a fixed connection between the heat sink 23 and the electronic switch 221 and the rectifier 222, a first assembly opening 2211 is provided on the electronic switch 221, a second assembly opening 2221 is provided on the rectifier 222, and a plurality of third assembly openings 231 are provided on the heat sink 23. The first assembly opening 2211 is connected to the third assembly openings 231 in a one-to-one correspondence, and the second assembly opening 2221 is connected to the third assembly openings 231 in a one-to-one correspondence. A first connector passes through the first and third assembly openings 2211, 231 to secure the electronic switch 221 to the heat sink 23, and a second connector passes through the second and third assembly openings 2221, 231 to secure the rectifier 222 to the heat sink 23. Screws can be used for the first and second connectors.

[0133] In some embodiments, four third assembly openings 231 are provided on the second heat dissipation portion 233 of the radiator 23, a first assembly opening 2211 is provided on each electronic switch 221, and a second assembly opening 2221 is provided on the rectifier 222. The first connecting member passes through the first assembly opening 2211 of an electronic switch 221 located on one side of the second heat dissipation portion 233, a third assembly opening 231 on the radiator 23, and the first assembly opening 2211 of another electronic switch 221 located on the other side of the second heat dissipation portion 233 to realize the assembly of the radiator 23 and the two electronic switches 221, so that the six electronic switches 221 can be fixed to the radiator 23 using only three first connecting members, and the remaining third assembly opening 231 is for the second connecting member to pass through.

[0134] In some parallel embodiments, as shown in Figures 22 to 24, when the power tool is in working state, the circuit boards are basically arranged vertically, and two radiators 23 are provided. The two radiators 23 are respectively a first radiator 2301 and a second radiator 2302. The first radiator 2301 and the second radiator 2302 respectively dissipate heat for each row of electronic switches 221.

[0135] As shown in Figures 23 and 24, 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 body 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 body mounting plate 234 is an arc-shaped plate, and the first heat dissipation ribs 2354 are protruding from the side of the first main body mounting plate 234 closer to the circuit element 22, or in other words, closer to the second capacitor 223. A first air flow channel 2351 is formed between two adjacent first heat dissipation ribs 2354, and a second air flow 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 relative to each other, so that the two first main body mounting plates 234 protrude in opposite directions, which can improve the smoothness of the air flow and thus improve the heat dissipation effect.

[0136] The directions of the air flow channels on the two heat sinks 23 of the first heat sink 2301 and the second heat sink 2302 are inclined to the board surface 201 of the circuit board. The air flow channel here refers to the channel for the heat dissipation air flow formed between any two adjacent heat dissipation ribs 235, which can be an air flow channel. For a heat sink 23, it can have the same direction of the air flow channel, or it can have multiple different directions of the air flow channels. In this embodiment, the first air flow channel 2351 and the second air flow channel 2352 are two different directions of the air flow channels. The board surface 201 of the circuit board can be the board surface of the first circuit board 211, or it can be the board surface of the second circuit board 212. In this embodiment, since the first circuit board 211 and the second circuit board 212 are basically parallel, the board surface 201 of the second circuit board 212 is used as an illustration in Figure 24.

[0137] By angling the airflow channel of the heat sink 23 and the circuit board surface 201, this power tool not only helps reduce the radial dimensions of the power tool, making it easier for the user to hold and operate the power tool, facilitating miniaturization, but also provides improved heat dissipation for the control assembly 20. As shown in FIG24 , the angle between the airflow channel of the heat sink 23 and the circuit board surface 201 is represented by a. In FIG24 , since the first heat sink 2301 and the second heat sink 2302 have substantially identical structures, the airflow channel here is described as the airflow channel 2352 formed by the first heat dissipation rib 2354 of the second heat sink 2302. Therefore, in this embodiment, one side of the angle a refers to the airflow channel 2352, and the other side refers to the circuit board surface 2112. In some embodiments, the angle a between the airflow channel of the heat sink 23 and the circuit board surface 201 is greater than 0° and less than or equal to 90°. In one embodiment, the angle a between the air flow channel of the heat sink 23 and the board surface 201 of the circuit board is 90°; in one embodiment, the angle a between the air flow channel of the heat sink 23 and the board surface 201 of the circuit board is 60°; in one embodiment, the angle a between the air flow channel of the heat sink 23 and the board surface 201 of the circuit board is 30°.

[0138] In some parallel embodiments, the angle a formed between the air passage 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°.

[0139] In some parallel embodiments, the angle a formed between the air passage 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°.

[0140] Continuing with Figures 23 and 24 , in addition to the first heat sink 2301 and the second heat sink 2302, the control assembly 20 also includes a third heat sink 2303, which is used to dissipate heat from the rectifier 222. In some embodiments, the third heat sink 2303 includes a second main mounting plate 236 and a plurality of third heat dissipation ribs 237. The second main mounting plate 236 is a flat plate, and the second heat dissipation ribs 237 are protruding from the outside of the third main mounting plate 236, with airflow channels formed between adjacent third heat dissipation ribs 237. It should be noted that after the second and second heat sinks 2302 and 2303 are installed, the third heat sink 2303 is mounted to the underside of the second and second heat sinks 2302 and 2302, with the third heat dissipation ribs 237 protruding downward. This improves the smoothness of airflow and thus the heat dissipation effect.

[0141] It should be noted that the air flow channel formed on the third radiator 2303 can be arranged parallel to or at an angle to the air flow channels of the first radiator 2301 and the second radiator 2302. Therefore, the range of the angle a described above also applies to the third radiator 2303.

[0142] As shown in Figures 23 and 24, in order to achieve a fixed connection between the radiator 23 and the electronic switch 221, a first assembly port 2211 is provided on the electronic switch 221, and a plurality of third assembly ports 231 are respectively provided on the first radiator 2301 and the second radiator 2302. The first assembly port 2211 is connected to the third assembly port 231 in a one-to-one correspondence, and the first connecting member passes through the first assembly port 2211 and the third assembly port 231 to achieve the fixation of the electronic switch 221 and the radiator 23.

[0143] In order to achieve a fixed connection between the third radiator 2303 and the rectifier 222, a second assembly port 2221 is provided on the rectifier 222, and a third assembly port 231 is provided on the third radiator 2303. The second assembly port 2221 is connected to the third assembly port 231 in a one-to-one correspondence, and the second connecting member passes through the second assembly port 2221 and the third assembly port 231 to achieve the fixation of the rectifier 222 and the radiator 23.

[0144] In some embodiments, three third assembly openings 231 are respectively provided on the first heat sink 2301 and the second heat sink 2302 , one third assembly opening 231 is provided on the third heat sink 2303 , a first assembly opening 2211 is provided on each electronic switch 221 , and a second assembly opening 2221 is provided on the rectifier 222 .

[0145] Continuing with reference to Figures 23 and 24, the control component 20 also includes a fourth radiator 2304. The fourth radiator 2304 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 arranged in the control box 24. The fourth radiator 2304 includes a plurality of fourth heat dissipation ribs formed on the circumference of the control box 24, and air flow channels are formed between adjacent fourth heat dissipation ribs. It should be noted that the above range of the angle a also applies to the fourth radiator 2304.

[0146] The shape of the circuit board can be flexibly adjusted according to the shape of the control box 24 or the shape of the internal space of the grip portion 11. The circuit board can be configured as a rectangular plate, a circular plate, or other polygonal plate. Of course, as shown in FIG. 24 , the circuit board can also be a non-circular plate 204 with side walls formed by curved surfaces 203 and flat surfaces 202.

[0147] In one specific embodiment, a non-circular plate 204 is formed by cutting the circuit board three times in a radial direction perpendicular to the circular plate, wherein the cut surfaces are the aforementioned planes 202. The three planes 202 are located in three directions of the circuit board, for example, the top, left, and right sides, or the bottom, left, and right sides. Two of the three planes 202 are arranged parallel to each other and perpendicular to the remaining plane 202. Furthermore, the circuit board includes three curved surfaces 203, each of which is arranged between two adjacent planes 202.

[0148] In one specific embodiment, the diameter of the curved surface 203 of the non-circular plate 204 is 51 mm; the distance between the two parallel flat surfaces 202 is 45 mm; and the distance between the remaining flat surface 202 and the curved surface 203 on the opposite side thereof is 48.5 mm. In one specific embodiment, the diameter of the curved surface 203 of the non-circular plate 204 is 51 mm; the distance between the two parallel flat surfaces 202 is 45 mm; and the distance between the remaining flat surface 202 and the curved surface 203 on the opposite side thereof is 46.5 mm.

[0149] In a specific embodiment, as shown in FIG26 , heat dissipation holes 2111 are provided on the circuit board. The arrangement of the heat dissipation holes 2111 allows heat dissipation air to flow smoothly through the circuit board when the circuit board is positioned perpendicular to the extension direction of the grip portion 11, thereby ensuring heat dissipation. The shape and number of the heat dissipation holes 2111 can be flexibly configured according to needs.

[0150] As shown in Figure 27, the anti-electromagnetic interference device 30 is used to suppress electromagnetic interference. In some embodiments, the anti-electromagnetic interference device 30 and the control component 20 are separately provided. By separately providing the electromagnetic interference device 30 and the control component 20, the electromagnetic interference device 30 and the control component 20 can make full use of the space inside the power tool for layout, which is conducive to the miniaturization of the power tool. In a specific embodiment, in the extension direction of the grip 11, the anti-electromagnetic interference device 30 is provided behind the control component 20. Of course, in some other embodiments, the anti-electromagnetic interference device 30 can also be integrated with the control component 20.

[0151] In some embodiments, the minimum distance between the anti-electromagnetic interference device 30 and the control assembly 20 is greater than or equal to 10 mm. In one embodiment, the minimum distance between the anti-electromagnetic interference device 30 and the control assembly 20 is 9 mm; in one embodiment, the minimum distance between the anti-electromagnetic interference device 30 and the control assembly 20 is 8 mm; in one embodiment, the minimum distance between the anti-electromagnetic interference device 30 and the control assembly 20 is 7 mm; and in one embodiment, the minimum distance between the anti-electromagnetic interference device 30 and the control assembly 20 is 6 mm.

[0152] Continuing to refer to FIG. 27 , the anti-electromagnetic interference device 30 includes an anti-electromagnetic interference circuit board 31 , a first capacitor 32 , a resistor 33 and an inductor 34 . The first capacitor 32 , the resistor 33 and the inductor 34 are all integrated on the anti-electromagnetic interference circuit board 31 .

[0153] In some embodiments, the anti-electromagnetic interference circuit board 31 is configured as a single board. Of course, in other embodiments, the anti-electromagnetic interference circuit board 31 can also be configured as a multi-board structure as needed. In some embodiments, the anti-electromagnetic interference circuit board 31 is arranged parallel to the extension direction of the grip portion 11; in some parallel embodiments, the anti-electromagnetic interference circuit board 31 is arranged at an angle relative to the extension direction of the grip portion 11.

[0154] In some embodiments, the maximum length of the anti-electromagnetic interference circuit board 31 is less than 65 mm. In one embodiment, the maximum length of the anti-electromagnetic interference circuit board 31 is 60 mm; in one embodiment, the maximum length of the anti-electromagnetic interference circuit board 31 is 58 mm; in one embodiment, the maximum length of the anti-electromagnetic interference circuit board 31 is 55 mm; in one embodiment, the maximum length of the anti-electromagnetic interference circuit board 31 is 52 mm; and in one embodiment, the maximum length of the anti-electromagnetic interference circuit board 31 is 40 mm.

[0155] In some parallel embodiments, the maximum length of the anti-electromagnetic interference circuit board 31 is less than 55 mm.

[0156] In some parallel embodiments, the maximum length of the anti-electromagnetic interference circuit board 31 is less than 45 mm.

[0157] In some embodiments, the area of ​​the anti-electromagnetic interference circuit board 31 is less than or equal to 1500 square millimeters. In one embodiment, the area of ​​the anti-electromagnetic interference circuit board 31 is 1400 square millimeters; in one embodiment, the area of ​​the anti-electromagnetic interference circuit board 31 is 1300 square millimeters; in one embodiment, the area of ​​the anti-electromagnetic interference circuit board 31 is 1200 square millimeters; in one embodiment, the area of ​​the anti-electromagnetic interference circuit board 31 is 1100 square millimeters; and in one embodiment, the area of ​​the anti-electromagnetic interference circuit board 31 is 1000 square millimeters.

[0158] In some embodiments, the resistor 33 is a power NTC resistor, and the inductor 34 is a common-mode inductor.

[0159] Furthermore, in some embodiments, the anti-electromagnetic interference device 30 further includes a mounting box, and the anti-electromagnetic interference 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 grip portion 11 includes at least a mounting plane, and the mounting box 36 is fixed to the mounting plane.

[0160] It should be noted that if control assembly 20 includes control box 24 and anti-electromagnetic interference device 30 includes mounting box 36, then the minimum distance between anti-electromagnetic interference device 30 and control assembly 20 refers to the minimum distance between control box 24 and mounting box 36. If control assembly 20 does not include control box 24 or anti-electromagnetic interference device 30 does not include mounting box 36, the minimum distance is calculated based on the boundaries of the circuit boards in circuit board assembly 21 or anti-electromagnetic interference circuit board 31, rather than the specific circuit components on the circuit boards.

[0161] In one embodiment, the minimum distance between the circuit board assembly 21 and the anti-electromagnetic interference circuit board 31 is greater than or equal to 5 mm. In one embodiment, the minimum distance between the circuit board assembly 21 and the anti-electromagnetic interference 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 anti-electromagnetic interference circuit board 31 can be 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, or 45 mm.

[0162] In some embodiments, continuing with reference to Figure 27, the anti-electromagnetic interference device 30 also includes an AC socket 35, which is mounted on the anti-electromagnetic interference circuit board 31. The anti-electromagnetic interference device 30 is arranged near the rear end of the casing 10, and the power cord 17 passes through the rear end of the casing 10 and can be directly electrically connected to the AC socket 35.

[0163] As shown in Figure 21, the speed regulator 40 is used to adjust the speed of the brushless motor 14. In some embodiments, the speed regulator 40 and the control assembly 20 at least partially overlap along the extension direction of the grip portion 11. This arrangement makes the internal structure of the power tool compact, which is conducive to miniaturization of the power tool.

[0164] 21 and 28 , the power tool further includes a motor switch 18 for the user to operate to control the start and stop of the brushless motor 14 . The motor switch 18 can be retractably mounted below the grip 11 . By pressing the motor switch 18 , the brushless motor 14 can be powered on and off.

[0165] In some embodiments, the motor switch 18 is disposed between the electromagnetic interference prevention device 30 and the control assembly 20. In some embodiments, the speed regulator 40 is located between the motor switch 18 and the brushless motor 14.

[0166] As shown in Figure 21, the entire layout of the power tool from back to front is: power cord 17 → anti-electromagnetic interference device 30 → motor switch 18 → speed regulator 40 → control component 20 → brushless motor 14 → transmission mechanism 15 → output shaft 12 and working accessories 13.

[0167] The brushless motor 14, control component 20 and anti-electromagnetic interference device 30 will generate a large amount of heat during operation. In order to improve the heat dissipation effect of the power tool, multiple ventilation holes are provided on the casing 10 so that air can form airflow inside and outside the power tool under the action of the electric fan to improve the heat dissipation effect.

[0168] In one embodiment, as shown in Figures 29 and 30 , the housing 10 is formed with a first air vent 104 located in front of the brushless motor 14, a second air vent 105 located at the control assembly 20, and a third air vent 106 located at the rear end of the grip 11. The fan 16 operates to form a heat dissipation airflow flowing in from the first air vent 104 and out from the second and third air vents 105, 106. Because the fan 16 is located between the brushless motor 14 and the control assembly 20, air enters from the front of the brushless motor 14 and exits from the rear of the control assembly 20 and the rear end of the grip 11. The air drawn in by the fan 16 cools the circuit board of the control assembly 20 and the brushless motor 14.

[0169] In one embodiment, as shown in Figures 29 and 31 , the housing 10 is formed with a first air vent 104 located in front of the brushless motor 14, a second air vent 105 located at the control assembly 20, a third air vent 106 located at the rear end of the grip 11, and at least one fourth air vent 107 radially opposite the fan 16. The fan 16 acts to form a heat dissipation airflow flowing in from the first air vent 104, the second air vent 105, and the third air vent 106, and out from the fourth air vent 107. Because the fan 16 is located between the brushless motor 14 and the control assembly 20, air is drawn in from three locations: in front of the brushless motor 14, behind the control assembly 20, and at the rear end of the grip 11, and air is discharged radially from the fan 16. The air drawn in from both the left and right sides of the fan 16 allows efficient cooling of the circuit board of the control assembly 20 and the brushless motor 14.

[0170] In a specific embodiment, a plurality of fourth air outlets 107 are provided, and the plurality of fourth air outlets 107 are arranged around the circumference of the housing 10 , thereby achieving multiple air outlets and further improving the heat dissipation effect.

[0171] In a specific embodiment, the air inlet direction of the third air vent 106 can be flexibly set according to needs. For example, the air inlet 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 inlet 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 inlet direction parallel to the central axis of the grip portion 11 and another third air vent 106 having an air inlet direction perpendicular to the central axis of the grip portion 11.

[0172] In order to achieve the miniaturization of the power tool, the size of the power tool is restricted as follows. Continuing with reference to Figure 9, the distance from the tail of the housing 10 to the center line of the output shaft 12 is a first length L3, and the first length L3 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 of the output shaft 12 excluding the eccentricity. The output shaft 12 can be installed with an eccentric block with an eccentric structure, and then the polishing disk is installed. In other words, the first length L3 here does not include the eccentricity.

[0173] Continuing with FIG9 , the distance from the rear end of the housing 10 to the front end of the stator 142 is a 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 one embodiment, the second length L4 is 275 mm; and in one embodiment, the second length L4 is 270 mm.

[0174] Continuing with FIG9 , the distance from the rear end of the housing 10 to the front 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 one embodiment, the overall length L5 of the power tool is 440 mm; in one embodiment, the overall length L5 of the power tool is 420 mm; and in one embodiment, the overall length L5 of the power tool is 400 mm.

[0175] Continuing with Figure 3 , the maximum height of the power tool at the motor switch 18 is a first height D3, which is less than or equal to 63 mm. The height of the power tool housing 10 at the motor switch 18 is a second height D4, which is less than or equal to 52 mm. It should be noted that the first height D3 is understood to be the sum of the second height D4 and the height of the motor switch 18 protruding from the housing 10.

[0176] As shown in Figures 32 to 34, the present application also provides an electric tool. In some embodiments, the electric tool can be a polisher, a sander, or an angle grinder. Of course, in other embodiments, the electric tool can be replaced with operating accessories as needed to make it a tool for performing other operations, such as an impact drill, an electric screwdriver, etc. The electric tool includes a housing 10, a motor 14, a chuck device 13, and a control assembly 20. The housing 10 is the main mounting component and protective component of the electric tool. The housing 10 can be an integral molded part or can be formed by connecting multiple parts. The housing 10 partially forms a gripping portion 11 for the user to hold, and the user holds the gripping portion 11 to operate the electric tool.

[0177] In some embodiments, as shown in FIG32 , the housing 10 includes a first shell 108 and a second shell 109 . The first shell 108 and the second shell 109 can be integrally formed parts or a spliced ​​structure formed by splicing half shells. As shown in FIG33 , the control component 20 and the motor 14 are both installed in the housing 10. A through hole is formed at the rear of the housing 10 for the power cord 17 to extend into. The power cord 17 is electrically connected to the control component 20. In some embodiments, the motor 14 is placed in the first shell 108 and the control component 20 is placed in the second shell 109. In some embodiments, the second shell 109 is a grip portion 11 , and an anti-slip structure is provided on the grip portion 11 to improve the stability of the user holding the grip portion 11. The anti-slip structure can be an anti-slip rubber sleeve, anti-slip grooves, etc. In some embodiments, the first shell 108 and the second shell 109 are both cylindrical structures.

[0178] The motor 14 is the power component of the power tool. It is equipped with or connected to a motor shaft. The power tool also includes a transmission mechanism and an output shaft. The transmission mechanism is connected between the motor shaft and the output shaft and is used to transmit power between the motor shaft and the output shaft. The bottom end of the output shaft is connected to the chuck device 13. Driven by the motor 14, the chuck device 13 can rotate about a straight line through the transmission mechanism and the output shaft. The chuck device 13 can clamp the polishing disk, which can be used to grind and polish the workpiece.

[0179] In some embodiments, when the power tool is in working state, the motor shaft is basically arranged horizontally, and the output shaft is basically arranged vertically, the transmission mechanism includes a planetary gear assembly, a first bevel gear, a second bevel gear, a first reduction shaft and a second reduction shaft, the motor shaft of the motor 14 is coaxially connected to the first reduction shaft, the first reduction shaft is connected to the sun gear of the planetary gear assembly, the second reduction shaft is connected to the planetary carrier of the planetary gear assembly, the first bevel gear is formed or connected to the second reduction shaft, and the second bevel gear is formed or connected to the output shaft.

[0180] In some embodiments, the power tool is an AC tool, and the motor 14 is a brushless motor.

[0181] The control assembly 20 is used to control the motor 14. As shown in FIG34 , the control assembly 20 includes a circuit board assembly 21, a circuit element 22, and a control box 24. The circuit board assembly 21 and the circuit element 22 are both disposed within the control box 24, with the circuit element 22 being integrated onto the circuit board assembly 21. To secure the circuit board assembly 21 and the circuit element 22 within the control box 24, the circuit element 22 is mounted onto the circuit board assembly 21, and then the entire assembly formed by the circuit element 22 and the circuit board assembly 21 is placed within the control box 24. A colloid is then injected into the control box 24 to secure the circuit board assembly 21 and the circuit element 22 within the control box 24. Furthermore, injecting the colloid into the control box 24 provides a certain degree of waterproofing and dustproofing.

[0182] The circuit board assembly 21 includes at least one circuit board. In some embodiments, the circuit board assembly 21 includes one circuit board; in some embodiments, the circuit board assembly 21 includes two circuit boards. Of course, the number of circuit boards included in the circuit board assembly 21 is not limited to two and can be three, four, or more circuit boards as needed. It should be noted that to improve the structural compactness of the control assembly 20, the multiple circuit boards are arranged substantially in parallel.

[0183] In some embodiments, when the power tool is in working state, the circuit board is basically arranged horizontally and parallel to the central axis of the grip 11; in some parallel embodiments, when the power tool is in working state, the circuit board is basically arranged vertically and perpendicular to the central axis of the grip 11; of course, in other embodiments, when the power tool is in working state, the circuit board can also be arranged at an angle and at an acute angle or an obtuse angle to the central axis of the grip 11.

[0184] Continuing with reference to FIG34 , the circuit element 22 includes a plurality of electronic switches 221, a rectifier 222, a capacitor 223, an inductor 224, a resistor 225, an AC line socket 226, and a control module. The plurality of electronic switches 221, the rectifier 222, the capacitor 223, the resistor 225, the AC line socket 226, and the control module are all fixed and electrically connected to 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 some embodiments, the plurality of electronic switches 221, the rectifier 222, the capacitor 223, the resistor 225, and the AC line socket 226 are fixed on some circuit boards, and the control module is provided on another circuit board. It should be noted that, depending on the needs, the circuit element 22 includes one or more of the plurality of electronic switches 221, the rectifier 222, the capacitor 223, the inductor 224, the resistor 225, and the AC line socket 226.

[0185] Multiple electronic switches 221 are used to drive motor 14. Specifically, multiple electronic switches 221 form a three-phase bridge circuit, and rectifier 222 forms a DC unit. It receives AC power input from power line 17 and outputs a DC bus voltage. In other words, it converts the AC power input through power line 17 into pulsating DC power output. A control module is used to control the conduction state of multiple electronic switches 221, thereby driving the normal operation of motor 14. In some embodiments, the control module is implemented using a control chip.

[0186] In some embodiments, the electronic switch 221 is perpendicular to the circuit board. In some embodiments, the electronic switch 221 is an IGBT, which stands for field-effect transistor; in some embodiments, the electronic switch 221 is a MOS; in some embodiments, the electronic switch 221 is a FET, which stands for field-effect transistor.

[0187] In some embodiments, a plurality of electronic switches 221 are regularly arranged on the circuit board, for example, they can be arranged in rows and columns or in a ring. In some embodiments, six electronic switches 221 are provided, and the six electronic switches 221 are arranged in two rows and three columns. Three capacitors 223 are provided, and the three capacitors 223 are arranged in a row and arranged side by side with the six electronic switches 221 in the length direction of the circuit board. The rectifier 222 and the three capacitors 223 are arranged side by side in the width direction of the circuit board. Of course, in other embodiments, the number of electronic switches 221 and capacitors 223 can be flexibly adjusted according to demand, and the arrangement of the electronic switches 221, rectifier 222, capacitors 223, inductor 224, resistor 225, and AC line socket 226 can also be flexibly adjusted according to the shape and size of the circuit board.

[0188] Inductor 224 and resistor 225 are electromagnetic interference protection devices. In some embodiments, inductor 224 is a common mode inductor and resistor 225 is a power NTC resistor. AC line socket 226 is used to connect to power line 17. In some embodiments, two AC line sockets 226 are provided.

[0189] The control box 24 is used to mount the circuit board assembly 21 and the circuit components 22, thereby integrating the control assembly 20 into a single unit for ease of assembly. The control box 24 is a box-like structure with an open top. In some embodiments, the control box 24 is a rectangular box. In other embodiments, the shape of the control box 24 can be adjusted based on the shape and size of the interior cavity of the housing 10.

[0190] The control assembly 20 is at least partially mounted within the second housing 109, and the first housing 108 and the second housing 109 jointly restrict the movement of the control box 24 along the extension direction of the second housing 109. In other words, at least one of the first housing 108 and the second housing 109 is provided with a retaining portion that restricts the movement of the control box 24. By utilizing the mutual cooperation of the first housing 108 and the second housing 109 to jointly restrict the movement of the control box 24 along the extension direction of the second housing 109, the power tool eliminates the screws used in the related art to secure the housing and the control box. This results in a compact connection between the housing 10 and the control box 24, and eliminates the need to increase the size of the second housing 109 or the control box 24 to accommodate the screw thread structure, thereby facilitating miniaturization of the power tool.

[0191] Continuing with reference to Figures 33 and 35 , a first limiting portion 1081 is formed on the housing 10, and a second limiting portion 2401 is formed on the control box 24. The first limiting portion 1081 and the second limiting portion 2401 are interlocked and engaged. Compared to the related art in which the control box is fixed to the first housing with screws or the control box is placed in the second housing and interlocked with limiting ribs, the power tool provided in the present application achieves a compact connection by interlocking the rear end of the housing 10 and the front end of the control box 24. This eliminates the need to increase the size of the second housing 109 or the control box 24 to accommodate a threaded structure that mates with the screws, thereby facilitating miniaturization of the power tool.

[0192] In some embodiments, the motor 14 is installed in the first housing 108 , the rear end of the first housing 108 forms a first limiting portion 1081 , and the front end of the control box 24 forms a second limiting portion 2401 .

[0193] In some embodiments, one of the first limiting portion 1081 and the second limiting portion 2401 is a limiting rib, and the other is a limiting groove, and the limiting rib and the limiting groove are engaged. In some embodiments, the first limiting portion 1081 is a limiting rib and the second limiting portion 2401 is a limiting groove; in another embodiment, the first limiting portion 1081 is a limiting groove and the second limiting portion 2401 is a limiting rib.

[0194] In some parallel embodiments, the first limiting portion 1081 includes a first limiting rib 10811 and a first limiting groove 10812, the second limiting portion 2401 includes a second limiting rib 24011 and a second limiting groove 24012, the first limiting rib 10811 is clamped with the second limiting groove 24012, and the second limiting rib 24011 is clamped with the first limiting groove 10812.

[0195] Furthermore, the number of the first limiting ribs 10811 and the first limiting grooves 10812 can be flexibly adjusted according to needs, so that the first limiting portion 1081 has a tooth-like structure, and a first limiting groove 10812 is formed between two adjacent first limiting ribs 10811; correspondingly, the number of the second limiting ribs 24011 and the second limiting grooves 24012 can be flexibly adjusted according to needs, so that the second limiting portion 2401 also has a tooth-like structure, and a second limiting groove 24012 is formed between two adjacent second limiting ribs 24011.

[0196] To enhance the connection strength between the control box 24 and the housing 10, in some embodiments, a plug-in cavity 1085 is formed at the rear end of the first housing 108, into which the front end of the control box 24 is inserted. A first stopper 1081 is formed on the inner wall of the plug-in cavity 1085, and a second stopper 2401 is formed on the outer wall of the control box 24. In some embodiments, the depth of the plug-in cavity 1085 is not less than the length of the control box 24, allowing the control box 24 to be completely placed within the plug-in cavity 1085, further enhancing the installation stability of the control box 24.

[0197] In some parallel embodiments, the front end of the control box 24 forms a plug-in cavity 1085, the rear end of the first shell 108 is inserted into the plug-in cavity 1085, the first limiting portion 1081 is formed on the outer wall surface of the control box 24, and the second limiting portion 2401 is formed on the inner wall surface of the plug-in cavity 1085.

[0198] To form the insertion cavity 1085, in some embodiments, the first housing 108 includes a plurality of rearwardly extending limiting posts 1082, which surround the insertion cavity 1085. In some parallel embodiments, the control box 24 includes a plurality of forwardly extending limiting posts 1082, which surround the insertion cavity 1085.

[0199] Continuing with reference to Figure 33, in order to achieve the connection between the first shell 108 and the second shell 109, the first shell 108 includes a mounting column 1083 extending backward, and a threaded hole 1084 is formed on the mounting column 1083. A mounting hole 1092 is formed on the second shell 109, and the screw 60 passes through the mounting hole 1092 and is threadedly connected to the threaded hole 1084.

[0200] In some embodiments, the mounting hole 1092 extends from the rear end of the second housing 109 to the front end of the second housing 109, and the screw 60 is inserted from the back to the front of the second housing 109. This arrangement not only facilitates the installation of the screw 60, but also improves the assembly strength of the second housing 109 and the first housing 108.

[0201] In some embodiments, the mounting posts 1083 and the limiting posts 1082 are arranged to form a plug-in cavity 1085. In some embodiments, as shown in FIG33 , there are two limiting posts 1082, one on the left and one on the right side of the first housing 108, and two mounting posts 1083, one on the top and one on the bottom side of the first housing 108.

[0202] Continuing with FIG36 , the power tool further includes a heat sink 23 for dissipating heat from the control assembly 20. The number of heat sinks 23 can be one or more, depending on the needs. In some embodiments, as shown in FIG36 to FIG40 , when the power tool is in operation, the circuit boards are arranged substantially horizontally. A single heat sink 23 is provided, defined as a first heat sink 2301. Specifically, the first heat sink 2301 is positioned above the circuit board and contacts the surfaces of the plurality of electronic switches 221 and the rectifier 222. The first pins 2211 of the electronic switches 221 and the second pins 2221 of the rectifier 222 are soldered to the back surface of the circuit board. The first heat sink 2301 dissipates heat from the electronic switches 221 and the rectifier 222 to prevent malfunctions caused by overheating. In some embodiments, the heat sink 23 is formed with a heat dissipation channel 23013 substantially parallel to the motor shaft of the motor 14.

[0203] Continuing with reference to Figure 40, the above-mentioned first heat sink 2301 includes a first heat dissipation portion 23011 and a second heat dissipation portion 23012 vertically connected. The first heat dissipation portion 23011 is basically horizontally arranged and is arranged above multiple electronic switches 221 and rectifiers 222. A plurality of heat dissipation channels 23013 that are basically parallel to the circuit board and the motor shaft are formed on the first heat dissipation portion 23011. The second heat dissipation portion 23012 is inserted between the two rows of electronic switches 221 and is in contact with the two rows of electronic switches 221 and the rectifier 222. Such an arrangement can improve the heat dissipation effect and heat dissipation efficiency.

[0204] To achieve a fixed connection between the first heat sink 2301, the electronic switch 221, and the rectifier 222, a first assembly opening is provided on the electronic switch 221, a second assembly opening is provided on the rectifier 222, and multiple third assembly openings are provided on the first heat sink 2301. The first assembly opening is connected to the third assembly openings in a one-to-one correspondence, and the second assembly opening is connected to the third assembly openings in a one-to-one correspondence. The first connector 61 passes through the first and third assembly openings to secure the electronic switch 221 to the first heat sink 2301, and the second connector passes through the second and third assembly openings to secure the rectifier 222 to the first heat sink 2301. Screws can be used for the first connector 61 and the second connector.

[0205] In some embodiments, four third assembly ports are provided on the second heat dissipation portion 23012 of the first heat sink 2301, a first assembly port is provided on each electronic switch 221, and a second assembly port is provided on the rectifier 222. The first connecting member 61 passes through the first assembly port of an electronic switch 221 located on one side of the second heat dissipation portion 23012, a third assembly port on the first heat sink 2301, and the first assembly port of another electronic switch 221 located on the other side of the second heat dissipation portion 23012 to realize the assembly of the first heat sink 2301 and the two electronic switches 221, so that only three first connecting members 61 are used to achieve the fixation of the six electronic switches 221 to the first heat sink 2301, and the remaining third assembly port is for the second connecting member to pass through.

[0206] In some parallel embodiments, two heat sinks 23 are provided. In addition to the first heat sink 2301 described above, a second heat sink 2302 is also included. The first heat sink 2301 is used to dissipate heat for the plurality of electronic switches 221. The second heat sink 2302 is used to dissipate heat for the rectifier 222. The second heat sink 2302 may have the same structure as the first heat sink 2301, or may have different structures. In some embodiments, the second heat sink 2302 is a heat sink.

[0207] Continuing with Figures 37 to 39 , at least a portion of any circuit element 22 is formed into a plastic encapsulation layer 26 by low-temperature injection molding, and the plastic encapsulation layer 26 covers at least a portion of the circuit element 22. By forming the plastic encapsulation layer 26 on at least a portion of the circuit element 22, the power tool improves its metal dust resistance. Furthermore, forming the plastic encapsulation layer 26 by low-temperature injection molding improves efficiency, saves labor, and reduces costs.

[0208] Regarding low-temperature injection molding, it is a packaging process that uses a very low injection pressure to inject hot-melt adhesive material into the mold and quickly solidify it into shape. The excellent sealing and excellent physical and chemical properties of the hot-melt adhesive material achieve insulation, heat resistance, impact resistance, shock absorption, moisture resistance, waterproofness, dust resistance, and chemical corrosion resistance. In addition, the process of low-temperature injection molding is simple and can be completed in three steps: plug-in, injection molding, and testing. The lowest injection pressure of low-temperature injection molding is as low as 1 bar, thus ensuring that the molded object is not damaged by pressure; the lowest injection temperature of low-temperature injection molding is as low as 150°C, thus preventing the molded object from being damaged by high temperature. Even if the molded object is a button battery, it can be properly protected; low-temperature injection molding has an extremely fast molding speed, which is as fast as a few seconds (1 second to tens of seconds), greatly improving production efficiency.

[0209] The use of low-temperature injection molding to encapsulate and protect the circuit elements 22 also has the following advantages: 1. It has a flexible structural design that can support diversified assembly requirements; 2. It is conducive to achieving consistency and versatility of parts, and achieving quantifiable production; 3. It has the advantages of sealing, waterproofing, shock resistance, stress relief, and reducing tedious processes; 4. It is conducive to improving the structural function of the product, eliminating the need for a shell, and realizing product aesthetics.

[0210] Furthermore, the injection molding equipment for low-temperature injection molding can adopt dual-station, dual-gun side-type injection, with a larger application space and suitable for complex molds with multiple cavities and slider mechanisms. The injection molding equipment has the following characteristics: 1. The injection system uses the latest super-hard gear pump and injection gun, which has a compact structure, stable injection, and long service life; 2. The operation table and dissolution system adopt a separate layout for flexible use; 3. The mold frame adopts a standard design for easier interchangeability, and the workbench is equipped with a product ejection device to facilitate product removal from the mold; 4. The optional dual glue cylinders provide more stable injection, higher production efficiency, and wider application.

[0211] In some embodiments, the plastic sealing layer 26 is a PA layer, PA is Polyamide, also known as polyamide; in some parallel embodiments, the plastic sealing layer 26 is a PO layer, PO is Polyolefin, also known as polyolefin; in some embodiments, the plastic sealing layer 26 is a PE layer, also known as polyethylene; in some embodiments, the plastic sealing layer 26 is an LDPE layer, also known as low-density polyethylene or high-pressure polyethylene; in some embodiments, the plastic sealing layer 26 is an HDPE layer, also known as high-density polyethylene; in some embodiments, the plastic sealing layer 26 is a PC layer, also known as polycarbonate; in some embodiments, the plastic sealing layer 26 is a polyolefin layer; in some embodiments, the plastic sealing layer 26 is a PP layer, also known as polypropylene; in some embodiments, the plastic sealing layer 26 is a PS layer, also known as polystyrene; in some embodiments, the plastic sealing layer 26 is a PVC layer, also known as polyvinyl chloride.

[0212] In some embodiments, multiple electronic switches 221 are provided, and the power tool further includes a first plastic layer formed on the exterior of at least two electronic switches 221, with first pins 2211 of the electronic switches 221 extending out of the first plastic layer. It should be noted that the first plastic layer is molded on the exterior surfaces of at least two electronic switches 221, and the exterior surface between two adjacent electronic switches 221 may or may not be provided with the first plastic layer. In some embodiments, the first plastic layer is molded on the exterior surfaces of six electronic switches 221, and each electronic switch 221 has three first pins 2211.

[0213] In some embodiments, the plurality of electronic switches 221 are arranged on both sides of the second heat dissipation portion 23012 and are in contact with the bottom surface of the first heat dissipation portion 23011, and one end of the first plastic encapsulation layer extends to the bottom surface of the first heat dissipation portion 23011. This arrangement does not affect the heat dissipation effect of the first heat sink 2301.

[0214] In some parallel embodiments, at least a portion of the rectifier 222 forms a second plastic layer, and the second pins 2221 of the rectifier 222 extend out of the second plastic layer. In some embodiments, the rectifier 222 has eight second pins 2221 .

[0215] In some parallel embodiments, a plurality of electronic switches 221 are provided, and at least a portion of the electronic switches 221 and at least a portion of the rectifier 222 together form a third plastic packaging layer, and the first pin 2211 of the electronic switch 221 and the second pin 2221 of the rectifier 222 both extend out of the third plastic packaging layer.

[0216] In some parallel embodiments, multiple types of circuit elements 22 are provided, and at least two types of circuit elements 22 together form a fourth plastic encapsulation layer. It should be noted that the fourth plastic encapsulation layer is molded on the outer surfaces of at least two types of circuit elements 22. The fourth plastic encapsulation layer may or may not be provided on the outer surface between two adjacent circuit elements 22. It should be noted that the first plastic encapsulation layer, the second plastic encapsulation layer, the third plastic encapsulation layer, and the fourth plastic encapsulation layer are all considered the plastic encapsulation layer 26, but are distinguished by different names in different embodiments and molding locations.

[0217] Furthermore, a portion of the circuit element 22 is placed in the colloid, and the portion of the circuit element 22 exposed outside the colloid is sealed by low-temperature injection molding to form a plastic layer 26 .

[0218] Continuing with FIG. 32 , the power tool further includes a motor switch 18 for user operation to control the start and stop of the motor 14. The motor switch 18 can be activated by pressing a button. In some embodiments, the motor switch 18 is retractably mounted below the grip 11. Pressing the motor switch 18 can power the motor 14 on and off. In some alternative embodiments, the motor switch 18 is disposed on the rear end of the housing 10. In some specific embodiments, the motor switch 18 is electrically connected to the control assembly 20 via a wire.

[0219] As shown in FIG41 , the housing 10 is formed with a vent 1091, to which a dust cover 50 is detachably attached. When the power tool is in operation, the dust cover 50 is removed, allowing air to flow smoothly in and out of the housing 10 through the vent 1091, thereby forming a heat dissipation airflow through the control assembly 20 and the motor 14, thereby preventing overheating within the power tool and affecting its normal operation. When the power tool is finished working and needs to be stored, the dust cover 50 can be placed over the vent 1091. The dust cover 50 prevents external dust from entering the housing 10, thereby preventing dust from contaminating the control assembly 20 and the motor 14.

[0220] In some embodiments, a plurality of vents 1091 are provided, and the plurality of vents 1091 are regularly arranged on the housing 10, for example, in rows and columns. In some embodiments, the vents 1091 are waist-shaped holes. Of course, the shape of the vents 1091 can also be set to circular holes, square holes, etc. according to needs.

[0221] To achieve detachable connection of the dust cover 50, a snap-in slot is formed on the housing 10. As shown in Figure 42, the dust cover 50 includes a cover body 51 and a snap 52. The cover body 51 is used to close all the vents 1091, and the snap 52 is used to snap into the snap-in slot. In some embodiments, there are two snap-in slots, with a snap 52 provided at each end of the cover body 51. The two snaps 52 snap into the two corresponding slots.

[0222] In some embodiments, there are multiple groups of vents 1091. Correspondingly, as shown in FIG43 , there are multiple dust covers 50, which are disposed one-to-one within the multiple groups of vents 1091. In some embodiments, the multiple groups of vents 1091 are spaced apart in the circumferential direction of the housing 10.

[0223] The above shows and describes 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 form, and any technical solutions obtained by equivalent replacement or equivalent transformation fall within the scope of protection of this application.

Claims

1. An AC polishing machine, comprising: An output shaft is configured to drive a working accessory to move; A brushless motor having or connected to a motor shaft; A transmission mechanism, configured to realize transmission between the motor shaft and the output shaft; a housing, the housing forming a grip portion for a user to hold; control assemblies, including circuit board assemblies and circuit components; An anti-electromagnetic interference device is configured to suppress electromagnetic interference; in, 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 450 mm.

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. When viewed from a direction perpendicular to the first circuit board, the first circuit board and the second 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 in 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 assembly along the extension direction of the control assembly is less than or equal to 75 mm.

4. The AC polishing machine according to claim 2 or 3, wherein: The working attachment is configured to clamp a polishing disc; the projection area of ​​the first circuit board on the polishing plane of the polishing disc is less than or equal to 3000 square millimeters; the projection 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 anti-electromagnetic interference device includes an anti-electromagnetic interference circuit board, and the anti-electromagnetic interference circuit board is configured as a single-board structure.

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

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

8. The AC polishing machine according to claim 1, wherein: The AC polishing machine further comprises a fan, which is sleeved on the motor shaft and located between the brushless motor and the control assembly.

9. The AC polishing machine according to claim 8, wherein: The housing is formed with a first air outlet located in front of the brushless motor, a second air outlet located at the control component, and a third air outlet located at the rear end of the grip portion. Under the action of the fan, a heat dissipation airflow is formed that flows in from the first air outlet and flows out from the second air outlet and the third air outlet.

10. The AC polishing machine according to claim 8, wherein: The housing is formed with a first air outlet located in front of the brushless motor, a second air outlet located at the control component, a third air outlet located at the rear end of the grip portion, and at least one fourth air outlet radially opposite to the fan. Under the action of the fan, a heat dissipation airflow is formed flowing in from the first air outlet, the second air outlet, and the third air outlet and flowing out from the fourth air outlet.

11. The AC polishing machine according to claim 1, wherein: The brushless motor includes a first bearing supported at a front end of the motor shaft, wherein the first bearing at least partially overlaps with a stator of the brushless motor in an 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 a rear end of the motor shaft, wherein the second bearing at least partially overlaps with the fan in an axial direction of the motor shaft.

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

14. The AC polishing machine according to claim 13, wherein: The plane where the circuit board assembly is located 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, and the circuit board is a non-circular plate with a side wall formed by an arc surface and a plane.

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

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

18. The AC polishing machine according to claim 1, wherein: The circumference D2 of the motor housing of the brushless motor at the stator midline 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 10 mm and less than or equal to 50 mm, and the outer diameter of the brushless motor is greater than or equal to 30 mm and less than or equal to 65 mm.

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