A power tool

Abstract

This application discloses an electric tool. The electric tool includes a housing, a motor, a battery pack, an eccentric rotating assembly, a working head, and a circuit board. The housing includes a motor housing extending along a first direction a, a grip extending along a second direction b, and an extension portion. The extension portion is located at the end of the grip portion away from the motor housing. The angle m between the first direction a and the second direction b is greater than or equal to 80° and less than or equal to 150°. The motor is disposed within the motor housing and includes a stator, a rotor, and a motor shaft. The battery pack is detachably mounted on the extension portion to provide electrical energy to drive the motor. By providing an extension portion on the housing at the end away from the grip and detachably mounting the battery pack on the extension portion, this electric tool achieves a detachable external battery pack. This allows for convenient charging and maintenance, as well as easy repair and replacement.

Description

Technical Field

[0001] This application relates to a power device, for example, to an electric tool. Background Technology

[0002] A sander, in related technologies, is an electric tool used to grind and polish the surface of objects. Sanders can replace traditional hand sanding, helping to improve work efficiency and surface treatment quality. Therefore, sanders are widely used in woodworking, metal processing, building decoration, automobile repair and other fields.

[0003] Existing sanders can be powered by battery packs, which are usually built into the sander. This means that the sander can only be moved to a charging point for charging, which is very inconvenient. Furthermore, if the battery pack malfunctions and needs to be repaired or replaced, the sander can only be disassembled for operation, which is also very inconvenient for maintenance.

[0004] This section provides background information related to this application, which is not necessarily prior art. Summary of the Invention

[0005] One object of this application is to solve or at least alleviate some or all of the aforementioned problems. Therefore, one object of this application is to provide a power tool with an externally mounted battery pack, which facilitates charging and subsequent maintenance.

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

[0007] An electric tool includes: a housing comprising a motor housing extending along a first direction a, a grip portion extending along a second direction b, and an extension portion disposed at the end of the grip portion away from the motor housing, wherein the angle m between the first direction a and the second direction b is greater than or equal to 80° and less than or equal to 150°; a motor disposed within the motor housing, the motor comprising a stator, a rotor, and a motor shaft; a battery pack detachably mounted to the extension portion for providing electrical energy to drive the motor to rotate; an eccentric rotation assembly coupled to the motor and driven to rotate by the motor shaft, the eccentric rotation assembly comprising a working head mounting portion; a working head mounted to the working head mounting portion and rotating eccentrically with the rotation of the eccentric rotation assembly; and a circuit board housed in the internal space formed by the extension portion, electrically connected to the battery pack and the motor, for converting the electrical energy output from the battery pack into the input electrical energy of the motor and controlling the operating state of the motor.

[0008] In some embodiments, the motor housing forms a sleeve interface along the first direction a for partially covering the eccentric rotation assembly.

[0009] In some embodiments, the power tool further includes a socket unit connected to the socket interface, which together with the socket interface covers the eccentric rotation assembly.

[0010] In some embodiments, the power tool further includes a speed control plate assembly electrically connected to the circuit board and disposed at the rear end of the motor housing, for detecting speed control operations and outputting speed setting commands to the circuit board.

[0011] In some embodiments, the grip portion is configured as a cylinder.

[0012] In some embodiments, the housing includes a first housing and a second housing, the first housing and the second housing being symmetrical about a first plane Q, the first plane Q being a plane formed by a first axis p of the motor shaft and a second axis q of the grip portion.

[0013] In some embodiments, the first housing and the second housing are connected by a plurality of fasteners, and the extension is connected by an embedded locking tab.

[0014] In some embodiments, the power tool further includes a lighting assembly disposed within the housing.

[0015] In some embodiments, the motor housing includes a head shell for accommodating the motor, the head shell having an extension length L in the first direction a of less than or equal to 79 mm.

[0016] An electric tool includes: a housing including a motor housing and a grip; a motor disposed within the motor housing, the motor including a stator, a rotor, and a motor shaft; a battery pack for providing electrical energy to drive the motor to rotate; an eccentric rotation assembly coupled to the motor and driven to rotate by the motor shaft, the eccentric rotation assembly including a working head mounting portion; a working head mounted to the working head mounting portion and rotating eccentrically with the rotation of the eccentric rotation assembly; the housing further includes an extension portion disposed on the side of the grip portion away from the motor housing; the extension portion includes a battery pack mating structure for fixing the battery pack to the extension portion, and the volume of the battery pack extending into the inner space of the grip portion is less than 10% of the total volume of the battery pack.

[0017] In some embodiments, the battery pack mating structure adopts a guide rail structure, allowing the battery pack to be slidably inserted along a third direction c.

[0018] In some embodiments, the guide rail structure is embedded in the extension portion, and after the battery pack is assembled into the extension portion, the upper surface of the battery pack is located above the bottom surface of the extension portion.

[0019] In some embodiments, the battery pack is symmetrical with respect to the first plane Q, and after the battery pack is installed to the extension, the first axis p of the motor shaft is located in the first plane Q.

[0020] In some embodiments, after the battery pack is installed into the extension, the bottom surface of the battery pack is parallel to the first axis p of the motor shaft.

[0021] In some embodiments, after the battery pack is inserted into the extension, the back end of the battery pack is flush with the grip portion.

[0022] In some embodiments, after the battery pack is inserted into the extension, the shortest distance L1 between the front end of the battery pack and the plane where the working head is located is greater than 10 mm.

[0023] In some embodiments, the center of gravity G0 of the battery pack is closer to the working head relative to the grip portion.

[0024] In some embodiments, the power tool further includes a circuit board disposed within the extension.

[0025] In some embodiments, the circuit board is nearly parallel to the bottom surface of the extension.

[0026] An electric tool includes: a housing comprising a motor housing extending along a first direction a, a grip portion extending along a second direction b, and an extension portion disposed at the end of the grip portion away from the motor housing; a motor disposed within the motor housing, the motor including a stator, a rotor, and a motor shaft; a battery pack detachably mounted to the extension portion for providing electrical energy to drive the motor to rotate; an eccentric rotation assembly coupled to the motor and driven to rotate by the motor shaft, the eccentric rotation assembly including a working head mounting portion; a working head mounted to the working head mounting portion and rotating eccentrically with the rotation of the eccentric rotation assembly; after the battery pack is mounted to the extension portion, the center of gravity G2 of the electric tool is located within the single-handed gripping range corresponding to the grip portion.

[0027] In some embodiments, the battery pack is a 12V, 1P battery pack.

[0028] In some embodiments, the first axis p of the motor shaft and the second axis q of the grip form a first plane Q, and the center of gravity G2 of the power tool is located within the first plane Q.

[0029] In some embodiments, the upper end of the grip is provided with a trigger. In the first plane Q, the machine center of gravity G2 of the power tool is located between the front end of the trigger and the back end of the power tool in the first direction a, and the machine center of gravity G2 of the power tool is located between the lower end of the trigger and the upper end of the extension in the second direction b.

[0030] The advantages of this application are:

[0031] The power tool provided in this application includes a housing, a motor, a battery pack, an eccentric rotating assembly, a working head, and a circuit board. The housing includes a motor housing extending along a first direction a, a grip portion extending along a second direction b, and an extension portion. The extension portion is located at the end of the grip portion away from the motor housing. The angle m between the first direction a and the second direction b is greater than or equal to 80° and less than or equal to 150°. The motor is disposed within the motor housing and includes a stator, a rotor, and a motor shaft. The battery pack is detachably mounted in the extension portion and is used to provide electrical energy to drive the motor to rotate. The eccentric rotating assembly is coupled to the motor and is driven to rotate by the motor shaft. The eccentric rotating assembly includes a working head mounting portion. The working head is mounted to the working head mounting portion and rotates eccentrically with the rotation of the eccentric rotating assembly. The circuit board is housed in the inner space formed by the extension portion and is electrically connected to the battery pack and the motor. It is used to convert the electrical energy output from the battery pack into the electrical energy input to the motor and to control the operating state of the motor. This power tool features an extension section on the end of the housing away from the grip, with the battery pack detachably mounted on the extension section. This allows for a removable and externally mounted battery pack, making charging convenient and allowing for easy repair and replacement, thus facilitating future maintenance. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a power tool without a battery pack;

[0033] Figure 2 yes Figure 1 A schematic diagram of the internal structure of the structure shown;

[0034] Figure 3 This is a schematic diagram of the main unit of a power tool;

[0035] Figure 4 yes Figure 1 A partial cross-sectional view of the structure shown;

[0036] Figure 5 yes Figure 1 A schematic diagram of the structure shown from another perspective;

[0037] Figure 6 This is a schematic diagram of another type of power tool without a battery pack;

[0038] Figure 7 yes Figure 6 A partial cross-sectional view of the structure shown;

[0039] Figure 8 yes Figure 7 Enlarged view of section F in the middle;

[0040] Figure 9 This is a schematic diagram of the working head of a power tool;

[0041] Figure 10 yes Figure 1 The diagram shows the structure and battery pack assembly.

[0042] Figure 11 This is an assembly diagram of the first type of battery pack;

[0043] Figure 12 This is an assembly diagram of the second type of battery pack;

[0044] Figure 13 This is an assembly diagram of the third type of battery pack;

[0045] Figure 14 This is an assembly diagram of the fourth type of battery pack.

[0046] In the picture:

[0047] 100. Housing; 101. Motor housing; 1011. Head housing; 102. Grip part; 103. Extension part; 1031. Internal space; 104. Sleeve interface; 110. First housing; 120. Second housing; 130. Fastener; 140. Locking plate; 150. Battery pack mating structure; 151. Guide rail structure; 160. Bearing seat; 170. First bearing; 180. Heat dissipation vent;

[0048] 200. Motor; 201. Stator; 202. Rotor; 203. Motor shaft;

[0049] 300, battery pack;

[0050] 400. Eccentric rotation assembly; 410. Eccentric rotation output part; 411. Input end; 412. Output end; 4121. First fitting structure; 4122. Eccentric shaft; 41221. Groove; 4123. Second bearing; 420. Working head mounting part; 421. Second fitting structure; 430. Counterweight unit; 431. First counterweight part; 432. Second counterweight part; 440. Limiting screw; 450. Fastening connection structure; 460. Limiting element; 401. Cylinder body; 402. Boss;

[0051] 500. Working head; 510. Connecting part; 520. Sanding base plate; 530. Insert;

[0052] 600. Circuit board;

[0053] 700, Sleeve Unit;

[0054] 800, Speed ​​control board assembly;

[0055] 900. Lighting assembly; 910. First lighting fixture; 920. Second lighting fixture;

[0056] 1000, trigger;

[0057] 1100, Flexible sleeve; 1101, Receiving cavity;

[0058] 10. Host computer. Detailed Implementation

[0059] Before explaining any implementation of this application in detail, it should be understood that this application is not limited to its application to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0060] In this application, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0061] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this application generally indicates that the preceding and following related objects have an "and / or" relationship.

[0062] In this application, the terms "connection," "combination," "coupling," and "installation" can refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, a direct connection refers to two parts or components being connected together without the need for an intermediary, while an indirect connection refers to two parts or components each being connected to at least one intermediary, with the connection achieved through the intermediary. Furthermore, "connection" and "coupling" are not limited to physical or mechanical connections or couplings, but can also include electrical connections or couplings.

[0063] In this application, those skilled in the art will understand that relative terms (e.g., “about,” “approximately,” “basically,” etc.) used in conjunction with quantities or conditions are to include the values ​​and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances associated with the particular value due to manufacturing, assembly, use, etc. Such terms should also be considered as disclosing a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​that do not use relative terms should also be disclosed as specific values ​​with tolerances. Furthermore, “basically” when expressing relative angular relationships (e.g., substantially parallel, substantially perpendicular) may refer to a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) added to or subtracted from the indicated angle.

[0064] In this application, those skilled in the art will understand that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0065] In this application, the directional terms "upper," "lower," "left," "right," "front," and "rear" are used to describe the orientation and positional relationships shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when an element is mentioned as being connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected through an intermediate element. It should also be understood that directional terms such as upper side, lower side, left side, right side, front side, and rear side not only represent positive orientation but can also be understood as lateral orientation. For example, "below" can include directly below, lower left, lower right, lower front, and lower rear.

[0066] The benefits, other advantages, and solutions to problems will be described below with reference to specific embodiments. However, these benefits, advantages, solutions to problems, and any features that may lead to or make any benefit, advantage, or solution appear or become more significant should not be construed as key, necessary, or essential features of any or all claims.

[0067] This application discloses a power tool capable of grinding workpieces to improve the surface quality. In some embodiments, the power tool is a sander. Of course, in other embodiments, the power tool may also be an angle grinder, a polisher, etc.

[0068] like Figures 1 to 10As shown, the power tool includes a housing 100, a motor 200, a battery pack 300, an eccentric rotating assembly 400, a working head 500, and a circuit board 600. The housing 100 is the main exterior and protective component of the power tool. The motor 200 and circuit board 600 are located inside the housing 100. At least part of the eccentric rotating assembly 400 is installed inside the housing 100. The battery pack 300 is installed on the housing 100 and is externally mounted. The working head 500 is externally mounted outside the housing 100.

[0069] The housing 100 includes a motor housing 101 extending along a first direction a, a grip portion 102 extending along a second direction b, and an extension portion 103. The grip portion 102 is disposed between the motor housing 101 and the extension portion 103, and the extension portion 103 is disposed at the end of the grip portion 102 away from the motor housing 101. The motor housing 101 is mainly used to mount the motor 200 and at least part of the eccentric rotating assembly 400, and a cavity for mounting the motor 200 and at least part of the eccentric rotating assembly 400 is formed within the motor housing 101. The grip portion 102 is for a user to hold. The extension portion 103 is used to mount the battery pack 300. The first direction a is as follows: Figure 1 As shown in direction a, the second direction b is as follows. Figure 1 As shown in the middle b direction, the angle between the first direction a and the second direction b is defined as m.

[0070] In some embodiments, the angle m between the first direction a and the second direction b is greater than or equal to 80° and less than or equal to 150°. In one specific embodiment, m is 80°, 85°, 90°, 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, or 150°. Of course, in other specific embodiments, m can also be other values ​​within the range of 80°-150°, and is not limited to the examples above.

[0071] In some embodiments, the motor housing 101 includes a head shell 1011, within which a motor cavity is formed for mounting the motor 200. Continuing to refer to... Figure 6 As shown, the extension length of the head shell 1011 in the first direction a is defined as L, where L is less than or equal to 79 mm. In one specific embodiment, L is 79 mm, 78 mm, 77 mm, 76 mm, 75 mm, 74 mm, 73 mm, 72 mm, 71 mm, or 70 mm. Of course, in other specific embodiments, L can also be other values ​​within the range of less than or equal to 79 mm, and is not limited to the examples above.

[0072] In some embodiments, the motor housing 101 forms a sleeve interface 104 along a first direction a, the sleeve interface 104 being used to partially cover the eccentric rotating assembly 400. The head housing 1011 and the sleeve interface 104 are interconnected in the first direction a. The head housing 1011 is located at the rear end of the power tool, and the sleeve interface 104 is located at the front end of the power tool. The front-rear direction of the power tool is the first direction a, and the front, rear, left, right, up, and down directions of the power tool are as follows: Figure 1 As shown in the figure. In some embodiments, the power tool further includes a socket unit 700, which is connected to a socket interface 104, and the socket unit 700 and the socket interface 104 together cover the eccentric rotation assembly 400.

[0073] A grip portion 102 is formed below the head shell 1011. In some embodiments, the grip portion 102 is configured as a cylinder. The cylindrical grip portion 102 is convenient for the user to hold, making the power tool more operable. To improve the anti-slip properties of the grip portion 102, an anti-slip structure may also be provided on the outer wall surface of the grip portion 102. For example, the anti-slip structure is an anti-slip pattern or an anti-slip rubber sleeve.

[0074] An extension portion 103 is formed below the grip portion 102. In some embodiments, the extension portion 103 is configured as a platform-like structure with a substantially horizontal bottom surface. An extension portion 103 with a substantially horizontal bottom surface is more convenient for placement. In some embodiments, the extension portion 103 is constructed as a hollow structure, with a circuit board 600 disposed within the extension portion 103. The wires of the circuit board 600 extend upwards through the grip portion 102 and are electrically connected to electrical control components such as the motor 200. The cavity formed within the cylindrical grip portion 102 can be used for wire routing; the wires on the circuit board 600 can extend towards the motor 200 through the cavity within the grip portion 102, achieving electrical connection with electrical control components such as the motor 200.

[0075] The housing 100 may adopt a split structure design. In some embodiments, the housing 100 includes a first housing 110 and a second housing 120. The first housing 110 and the second housing 120 are symmetrical with respect to a first plane Q. The first plane Q is a plane formed by the first axis p of the motor shaft 203 and the second axis q of the gripping part 102. The first axis p is the central axis of the motor shaft 203. The first axis p, the second axis q, and the first plane Q are as follows: Figure 2 As shown in the diagram. In one specific embodiment, the first plane Q is a vertical plane, and the first housing 110 and the second housing 120 are left and right symmetrical housings. Of course, in other embodiments, the housing 100 can also be a split structure composed of an upper housing and a lower housing, or the housing 100 can be a split structure composed of a front housing and a rear housing.

[0076] In some embodiments, the first housing 110 and the second housing 120 are both injection molded parts, and the first housing 110 and the second housing 120 are assembled after the first housing 110 and the second housing 120 are respectively injection molded.

[0077] In some embodiments, the first housing 110 and the second housing 120 are connected by a plurality of fasteners 130. Using a plurality of fasteners 130 to connect the first housing 110 and the second housing 120 helps to improve the connection strength between the first housing 110 and the second housing 120. In one specific embodiment, the fasteners 130 are fastening screws; in another specific embodiment, the fasteners 130 are combinations of bolts and nuts; and in yet another specific embodiment, the fasteners 130 are snap-fit ​​fasteners.

[0078] In some embodiments, the first housing 110 and the second housing 120 are connected at the formed extension 103 by an embedded locking tab 140. In one specific embodiment, the locking tab 140 adopts a C-shaped locking tab structure. Of course, in other specific embodiments, the locking tab 140 may be other types of locking tabs.

[0079] The motor 200 is the power component of the power tool and is housed within the motor housing 101. Specifically, the motor 200 includes a stator 201, a rotor 202, and a motor shaft 203. In some embodiments, the motor shaft 203 is approximately parallel to the first direction a. To improve the stability of the motor 200 within the motor housing 101, a support rib is provided on the inner wall of the motor housing 101. One end of the support rib, away from the inner wall of the motor housing 101, is supported on the outer wall of the motor 200. After the first housing 110 and the second housing 120 are assembled, the support ribs on the first housing 110 and the second housing 120 together form a limiting space for the motor 200, thereby improving the stability of the motor 200 within the motor housing 101.

[0080] The eccentric rotation assembly 400 is used to realize the transmission connection between the motor 200 and the working head 500, and to transmit the power of the motor 200 to the working head 500. Specifically, the eccentric rotation assembly 400 is coupled to the motor 200, and is driven to rotate by the motor shaft 203, transmitting the motion to the working head 500. It should be noted in advance that the eccentric rotation assembly 400 can be provided in various ways depending on the requirements. The main body 10 of the power tool is defined as the part of the power tool excluding the eccentric rotation assembly 400, the working head 500, and the battery pack 300. The main body 10 can meet different grinding requirements by cooperating with different eccentric rotation assemblies 400. In some embodiments, the eccentric rotation assembly 400 can include various specifications with different eccentricities, such as a 3mm eccentric assembly with an eccentricity of 3mm and a 5mm eccentric assembly with an eccentricity of 5mm. The 5mm eccentric assembly is as follows: Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, the 3mm eccentric component is as follows Figure 6 and Figure 7 As shown, the working head 500 connected to the 3mm eccentric component can be further configured to only perform translational motion, while the working head 500 connected to the 5mm eccentric component can not only perform translational motion but also rotational motion. By replacing the eccentric rotating component 400 with different eccentricities, point-like areas can be efficiently repaired and high-quality grinding can be achieved.

[0081] Continue to refer to Figure 4 and Figure 7 As shown, the eccentric rotation assembly 400 includes an eccentric rotation output section 410, which includes an input end 411 and an output end 412. The input end 411 is configured to detachably engage with the motor shaft 203 to receive the rotational power transmitted by the motor shaft 203. The eccentric rotation output section 410 converts the rotational power into an eccentric rotation with a preset eccentricity e, and outputs it outward through the output end 412. The eccentric rotation assembly 400 also includes a working head mounting section 420, which is fixedly connected to the output end 412 and can perform eccentric movement synchronously with the eccentric rotation of the output end 412. The working head 500 is mounted to the working head mounting section 420 and generates eccentric rotation with the rotation of the eccentric rotation assembly 400.

[0082] To improve the rotational stability of the eccentric rotation output section 410, in some embodiments, the power tool further includes a bearing housing 160, which is disposed within the housing 100 and houses a first bearing 170 for supporting the input end 411. In one specific embodiment, the bearing housing 160 is located at the head shell 1011. In another specific embodiment, the bearing housing 160 is integrally formed with the housing 100.

[0083] An insertion hole for inserting the motor shaft 203 is provided at the input end 411 along the first direction a. The motor shaft 203 of the motor 200 and the input end 411 are connected by insertion. When the motor shaft 203 of the motor 200 rotates around the first axis p, the input end 411 rotates synchronously around the first axis p under the drive of the motor shaft 203. That is, the central axis of the input end 411 is the first axis p.

[0084] In some embodiments, the working head mounting portion 420 abuts against the output end 412, restricting their axial relative displacement.

[0085] The output end 412 also includes an eccentric shaft 4122, and the output end 412 and the working head mounting part 420 are aligned with the eccentric shaft 4122. The central axis of the eccentric shaft 4122 is eccentrically set with respect to the central axis of the input end 411. The central axis of the eccentric shaft 4122 is defined as the third axis n. The third axis n is parallel to the first axis p, and the eccentricity is e.

[0086] In some embodiments, the eccentric shaft 4122 and the input end 411 are integrally formed shaft structures. A first stepped surface is provided on the portion of the shaft structure forming the input end 411, and the first bearing 170 abuts against the first stepped surface. A second stepped surface is provided on the portion of the shaft structure forming the eccentric shaft 4122.

[0087] The output end 412 also includes a second bearing 4123, which is sleeved on the outside of the eccentric shaft 4122. In some embodiments, to limit the second bearing 4123 on the eccentric shaft 4122, the eccentric rotation assembly 400 further includes a limiting screw 440, which is disposed on the edge of the eccentric shaft 4122 and is used to limit the relative displacement of the second bearing 4123 in the axial direction of the eccentric shaft 4122. In some embodiments, one end of the second bearing 4123 abuts against the second stepped surface, and the other end is limited and abutted against the limiting screw 440, so that the axial position of the second axis q on the eccentric shaft 4122 is fixed and no large displacement occurs.

[0088] In order to fix the limiting screw 440, in some embodiments, a groove 41221 is formed on the eccentric shaft 4122, the inner wall of the groove 41221 has an internal thread, and the limiting screw 440 cooperates with the groove 41221 to limit the axial displacement of the second bearing 4123.

[0089] Of course, in addition to using the limiting screw 440 to limit the second bearing 4123, in some parallel embodiments, when the output end 412 and the working head mounting part 420 are engaged, the working head mounting part 420 abuts against the second bearing 4123 to limit the axial displacement of the second bearing 4123.

[0090] Continue to refer to Figure 4 and Figure 7 As shown, the output end 412 of the eccentric rotation output part 410 has a first fitting structure 4121, and the working head mounting part 420 has a second fitting structure 421. The first fitting structure 4121 and the second fitting structure 421 fit together so that the central axis of the working head mounting part 420 and the central axis of the output end 412 remain coincident during the eccentric rotation.

[0091] Compared to related technologies where the eccentric rotation output section and the working head mounting section of power tools are fixedly connected by connectors such as screws, which cannot guarantee concentricity, misalignment leads to poor machine vibration. Poor vibration not only causes excessive noise during operation but also affects the grinding effect on the workpiece. The power tool disclosed in this application has a first fitting structure 4121 formed at the output end 412 of the eccentric rotation output section 410 and a second fitting structure 421 formed at the working head mounting section 420. By using the interlocking of the first fitting structure 4121 and the second fitting structure 421, the central axis of the working head mounting section 420 and the central axis of the output end 412 remain coincident during eccentric rotation. The addition of a fitting section between the first fitting structure 4121 and the second fitting structure 421 improves the concentricity of the working head mounting section 420 and the output end 412, avoiding poor machine vibration caused by assembly errors, thereby reducing vibration and noise during operation and improving the grinding effect.

[0092] In some embodiments, the first fitting structure 4121 is a separate element fixed to the output terminal 412. In some parallel embodiments, the first fitting structure 4121 is integrally formed with the output terminal 412.

[0093] In some embodiments, the second fitting structure 421 is a separate element fixed to the working head mounting portion 420. In some parallel embodiments, the second fitting structure 421 is integrally formed with the working head mounting portion 420.

[0094] Continue to refer to Figure 8 As shown, one of the first fitting structure 4121 and the second fitting structure 421 is configured as a cylinder 401 and the other is configured as a boss 402; the side wall of the cylinder 401 cooperates with the side wall of the boss 402 to limit the radial relative displacement between the output end 412 and the working head mounting part 420.

[0095] In some embodiments, the first fitting structure 4121 is a cylinder 401, and the second fitting structure 421 is a boss 402. The cylinder 401 is sleeved on the outside of the second bearing 4123. The central axis of the first fitting structure 4121, which forms the cylinder 401, is the third axis n, and the central axis of the second fitting structure 421, which forms the boss 402, is also the third axis n. Through the cooperation of the cylinder 401 and the boss 402, the eccentric movement of the eccentric shaft 4122 can be transmitted to the working head mounting part 420. The cylinder 401 is sleeved on the outside of the second bearing 4123, with one end connected to the eccentric shaft 4122 and the other end cooperating with the second fitting structure 421.

[0096] In some embodiments, the output end 412 and the working head mounting portion 420 are provided with a fastening connection structure 450 to restrict the separation of the output end 412 from the working head mounting portion 420. The fastening connection structure 450 improves the connection strength between the output end 412 and the working head mounting portion 420, further ensuring the concentricity of the two portions. In one specific embodiment, the fastening connection structure 450 is a fastening screw, with a first connecting hole on the output end 412 and a second connecting hole on the working head mounting portion 420, the fastening screw being connected within the first and second connecting holes. In one specific embodiment, multiple fastening screws are provided to further improve the connection strength. Of course, other structures can also be used as the fastening connection structure 450, such as pins, hooks, etc.

[0097] In some embodiments, one end of the cylinder 401 is engaged with the eccentric shaft 4122 to limit the axial displacement of the cylinder 401. Specifically, the end of the eccentric shaft 4122 away from the boss 402 is provided with a locking ring portion, and the end of the cylinder 401 away from the boss 402 is engaged with the locking ring portion. One side of the locking ring portion forms a second stepped surface, and the second bearing 4123 abuts against the second stepped surface.

[0098] Regarding the specific structures of the first fitting structure 4121 and the second fitting structure 421 forming the cylinder 401, in one specific embodiment, the first fitting structure 4121 includes a first cylinder portion, a second cylinder portion, and a third cylinder portion connected sequentially in the direction of the third axis n. The outer diameter of the second cylinder portion is larger than the outer diameter of the first cylinder portion and larger than the outer diameter of the third cylinder portion. The inner diameter of the second cylinder portion is equal to the inner diameter of the first cylinder portion and smaller than the outer diameter of the third cylinder portion. The second fitting structure 421 includes a first platform portion, a second platform portion, and a third platform portion connected sequentially in the direction of the third axis n. The outer diameter of the second platform portion is larger than the outer diameter of the first platform portion and larger than the outer diameter of the third platform portion.

[0099] In this structure, the first platform and the first cylindrical section are inserted into each other, and the outer wall of the first platform and the inner wall of the first cylindrical section mate to form a mating section, thereby limiting the radial relative displacement between the output end 412 and the working head mounting part 420. The second cylindrical section and the second platform are detachably connected by multiple locking screws. The second bearing 4123 is formed inside the third cylindrical section, and the end of the second bearing 4123 near the boss 402 abuts against the stepped annular surface formed between the second and third cylindrical sections. The first platform is constructed as a cylindrical structure, and the nut of the limiting screw 440 is located inside the second and first cylindrical sections and can extend into the cavity of the first platform to improve structural compactness. The third platform is constructed as a cylindrical structure to facilitate the installation of the working head 500.

[0100] Of course, in some parallel embodiments, the first fitting structure 4121 can also be constructed as a boss 402, the second fitting structure 421 can be constructed as a cylinder 401, and a second bearing 4123 can be provided between the boss 402 and the cylinder 401. The second bearing 4123 is sleeved outside the boss 402, and the cylinder 401 is sleeved outside the second bearing 4123.

[0101] In one specific embodiment, the second bearing 4123 forms a boss 402, and the second fitting structure 421 is a cylinder 401.

[0102] In some embodiments, one end of the cylinder 401 is engaged with the output end 412 to prevent the cylinder 401 from disengaging from the output end 412. For example, one end of the cylinder 401 is engaged with the output end 412 via an elastic retaining spring.

[0103] If the first and second sets of structures 4121 adopt a scheme in which the boss 402 and the cylinder 401 cooperate with each other, the dimensions of the mating part of the boss 402 and the cylinder 401 are as follows: In some embodiments, the thickness M0 of the boss 402 is 1.5mm-2mm. In some embodiments, the inner radius R of the cylinder 401 is 5mm-6mm.

[0104] In one specific embodiment, the thickness M0 of the boss 402 is 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, or 2.0mm. Of course, in other specific embodiments, the thickness M0 of the boss 402 can also be other values ​​in the range of 1.5mm-2mm, and is not limited to the foregoing examples.

[0105] In one specific embodiment, the inner radius R of the cylinder 401 is 5mm, 5.1mm, 5.2mm, 5.3mm, 5.4mm, 5.5mm, 5.6mm, 5.7mm, 5.8mm, 5.9mm, or 6.0mm. Of course, the inner radius R of the cylinder 401 can also be other values ​​within the range of 5mm-6mm, and is not limited to the aforementioned examples.

[0106] The eccentric rotation assembly 400 also includes a counterweight unit 430, which comprises a first counterweight part 431 and a second counterweight part 432. The counterweight unit 430 is sleeved on the eccentric rotation output part 410. The first counterweight part 431 is disposed near the input end 411, and the second counterweight part 432 is disposed near the output end 412. Exemplarily, both the first counterweight part 431 and the second counterweight part 432 are irregularly shaped annular structures. The eccentric rotation output part 410 also includes a connecting section connecting the input end 411 and the output end 412. The first counterweight part 431 is sleeved on the connecting section near the output end 412, and the second counterweight part 432 is sleeved outside the third cylindrical portion of the cylinder 401. In this position, most of the structure of the first counterweight part 431 and most of the structure of the second counterweight part 432 are located on different sides of the third axis n, and the two counterweight parts can cancel each other out, thereby achieving better balance in the vibration of the entire machine.

[0107] In some embodiments, the eccentric rotation assembly 400 further includes a limiting member 460, which has a through hole on the first counterweight 431 and a limiting hole in the radial direction of the connecting section. One end of the limiting member 460 passes through the through hole and is inserted into the limiting hole, thereby achieving radial fixation between the counterweight unit 430 and the eccentric rotation output part 410.

[0108] In some embodiments, the counterweight unit 430 is an integrally formed structure of the first counterweight part 431 and the second counterweight part 432. In some parallel embodiments, the counterweight unit 430 is an independently assembled structure of the first counterweight part 431 and the second counterweight part 432.

[0109] Continue to refer to Figure 7 As shown, the power tool also includes a flexible sleeve 1100. One end of the flexible sleeve 1100 is pre-stretched and fitted onto the housing 100 with an interference fit. The other end is fixedly connected to the working head mounting portion 420. The flexible sleeve 1100 forms a receiving cavity 1101, which is used to accommodate the eccentric rotating assembly 400. The flexible sleeve 1100 not only restricts the rotation of the working head mounting portion 420 with the output end 412, but also protects the eccentric rotating assembly 400.

[0110] In some embodiments, one end of the flexible sleeve 1100 is disposed between the working head mounting portion 420 and the output end 412, and the distance between the working head mounting portion 420 and the output end 412 is less than the thickness of the flexible sleeve 1100. This arrangement can improve the assembly stability of the working head mounting portion 420, the output end 412 and the flexible sleeve 1100.

[0111] In some embodiments, the flexible sleeve 1100 is made of HNBR (hydrogenated nitrile butadiene rubber), a high-performance elastomer material obtained by selective hydrogenation modification of nitrile butadiene rubber (NBR). HNBR has a heat resistance temperature up to 150°C and outperforms NBR in terms of heat resistance, chemical stability, ozone resistance, and radiation resistance, while NBR's heat resistance is only 120°C. These superior properties make HNBR a more suitable material for use in high-temperature and chemically corrosive environments.

[0112] In some embodiments, the flexible sleeve 1100 is a tapered sleeve, and the rear opening size of the flexible sleeve 1100 near the housing 100 is larger than the front opening size of the flexible sleeve 1100 near the working head 500. The flexible sleeve 1100 made of HNBR has an elongation rate of 12%-16% at its rear opening and a compression rate of 5%-10% at its front opening, while the structure made of NBR has an elongation rate of only 5%-10% at its rear opening. It should be noted that compression rate and elongation rate refer to the ratio of the change in volume ΔV to the original volume V, i.e., ΔV / V. Generally, a higher elongation rate indicates a more flexible rubber.

[0113] The working head 500 is detachably mounted on the working head mounting portion 420 and can rotate eccentrically with the rotation of the eccentric rotation assembly 400. In some embodiments, a threaded sleeve seat is provided in the cavity within the third portion of the working head mounting portion 420, and an internal thread is formed on the inner wall surface of the threaded sleeve seat. Continuing to refer to... Figure 9 As shown, the working head 500 includes a connecting part 510, and an external thread is formed on the outer wall surface of the connecting part 510. The working head 500 is threadedly connected to the working head mounting part 420 through the connecting part 510.

[0114] The working head 500 can be designed in various ways according to work requirements. In some embodiments, the working head 500 has a split structure, which includes a connecting part 510 and a sanding base plate 520. The sanding base plate 520 is a detachable component and has two types: a PSA base surface and a Velcro base surface. The PSA base surface refers to the plane on the sanding base plate 520 used for attaching sandpaper with PSA adhesive backing, while the Velcro base surface refers to the plane on the sanding base plate 520 used for attaching Velcro. Due to the different structures of the sanding base plates 520, the two sanding base plates 520 with different base surfaces have a weight difference of about 0.5g. This weight difference of the sanding base plates 520 will cause different vibrations in the whole machine after changing the working head 500. In order to reduce vibration, in some embodiments, an insert 530 is added inside the working head 500 with the Velcro base surface so that the weights of the two working heads 500 are approximately the same. In one specific embodiment, the connecting part 510 is a foamed structure, and the insert 530 is disposed within the foamed structure.

[0115] Continue to refer to Figure 10 As shown, the battery pack 300 is detachably mounted on the extension section 103 to provide electrical energy for the rotation of the drive motor 200. By detachably mounting the battery pack 300 on the extension section 103, the battery pack 300 is externally mounted. Compared to related technologies where the battery pack is built into the grip section, the power tool provided in this application achieves a detachable external battery pack 300 by providing an extension section 103 at one end of the housing 100 away from the grip section 102 and detachably mounting the battery pack 300 on the extension section 103. This not only allows for convenient charging but also facilitates repair and replacement, simplifying future maintenance. Furthermore, externalizing the battery pack 300 also facilitates heat dissipation, preventing excessive heat buildup inside the power tool and thus reducing its lifespan and operational status.

[0116] like Figures 11 to 14 As shown, the battery pack 300 is installed in the extension section 103 via a plug-in / plug-out method, with the plug-in / plug-out direction defined as the third direction c. In one specific embodiment, the third direction c is parallel to the first axis p, and the battery pack 300 can be assembled by horizontal insertion from front to back or from back to front; in another specific embodiment, the angle between the third direction c and the first axis p is an acute angle, and the battery pack 300 can be assembled by oblique insertion from front to back or from back to front; in yet another embodiment, the third direction c is perpendicular to the first axis p, and the battery pack 300 can be assembled by vertical insertion from bottom to top. Regarding the vertical assembly method, the battery pack 300 can be assembled as follows: Figure 12 As shown, it moves in and out of the assembly from top to bottom with its bottom surface translating relative to the ground. It can also be done as follows: Figure 13 As shown, the assembly proceeds from top to bottom with its bottom surface perpendicular to the ground.

[0117] To improve the stability of insertion and removal and reduce the difficulty of insertion and removal, the extension portion 103 includes a battery pack mating structure 150 for fixing the battery pack 300 to the extension portion 103. In some embodiments, the battery pack mating structure 150 adopts a guide rail structure 151 for the battery pack 300 to slide into the extension portion 103 along a third direction c. The guide rail structure 151 extends along the third direction c and is fixed within the extension portion 103. The battery pack 300 is assembled with the extension portion 103 by mating with the guide rail structure 151. Of course, in other embodiments, the battery pack mating structure 150 may also be a guide groove structure.

[0118] In some embodiments, the guide rail structure 151 is embedded in the extension portion 103. After the battery pack 300 is assembled into the extension portion 103, the upper surface of the battery pack 300 is located above the bottom surface of the extension portion 103. This arrangement ensures the stability of the assembly and prevents the battery pack 300 from accidentally detaching.

[0119] In some embodiments, the volume of the battery pack 300 extending into the inner space 1031 of the grip portion 102 is less than 10% of the total volume of the battery pack 300. This arrangement ensures a stable connection between the battery pack 300 and the housing 100, and also allows most of the battery pack 300's structure to be external. In one specific embodiment, the volume of the battery pack 300 extending into the inner space 1031 of the grip portion 102 is less than 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or 0% of the total volume of the battery pack 300. Of course, in other embodiments, the volume of the battery pack 300 extending into the inner space 1031 of the grip portion 102 can also be other values ​​within the range of less than 10% of the total volume of the battery pack 300.

[0120] In some embodiments, the battery pack 300 is symmetrical with respect to the first plane Q. After the battery pack 300 is installed to the extension 103, the first axis p of the motor shaft 203 is located in the first plane Q.

[0121] In some embodiments, after the battery pack 300 is installed into the extension 103, the bottom surface of the battery pack 300 is parallel to the first axis p of the motor shaft 203.

[0122] In some embodiments, after the battery pack 300 is inserted into the extension 103, the back end of the battery pack 300 is flush with the grip portion 102.

[0123] In some embodiments, after the battery pack 300 is inserted into the extension 103, refer to... Figure 10 As shown, the shortest distance L1 between the front end of the battery pack 300 and the plane where the working head 500 is located is greater than 10 mm. In a specific embodiment, the shortest distance L1 between the front end of the battery pack 300 and the plane where the working head 500 is located is 11 mm, 11.5 mm, 12 mm, 12.5 mm, or 13 mm.

[0124] In some embodiments, the battery pack 300 is a 12V, 1P battery pack 300. Of course, in other embodiments, the battery pack 300 may be of other types as needed.

[0125] In order to improve the user's comfort when operating the power tool and reduce the workload, after the battery pack 300 is assembled into the extension part 103, the center of gravity G2 of the power tool is located within the single-hand grip range corresponding to the grip part 102.

[0126] In some embodiments, the center of gravity G0 of the battery pack 300 is closer to the working head 500 relative to the grip 102.

[0127] In some embodiments, the center of gravity G2 of the power tool is located within the first plane Q. It should be noted that the center of gravity G2 of the power tool is the center of gravity of the power tool when it has the battery pack 300.

[0128] In some embodiments, a trigger 1000 is provided at the upper end of the grip 102. Within the first plane Q, the center of gravity G2 of the power tool is located between the front end of the trigger 1000 and the back end of the power tool in the first direction a, and between the lower end of the trigger 1000 and the upper end of the extension 103 in the second direction b. By setting the center of gravity G2 of the power tool within this range, it is easier for the user to use it.

[0129] With the upper end point of trigger 1000 as the origin O, the line passing through the origin and parallel to the first axis p of motor shaft 203 as the horizontal axis, and the line passing through the origin and perpendicular to the first axis p as the vertical axis, in one specific embodiment, the center of gravity G1 of the bare power tool without battery pack 300 is located in the fourth quadrant, and the coordinates are (13, -18). In another embodiment, the center of gravity G1 of the bare power tool without battery pack 300 and the center of gravity G2 of the machine with battery pack 300 are both located in the fourth quadrant, and within the 22×50 area enclosed by the four points (13, -18), (13, -68), (35, -18), and (35, -68).

[0130] The circuit board 600 is housed in the inner space 1031 formed by the extension portion 103, and is electrically connected to the battery pack 300 and the motor 200. It converts the electrical energy output from the battery pack 300 into the input electrical energy of the motor 200 and controls the operation of the motor 200. The circuit board 600 is a PCB assembly. Placing the circuit board 600 within the grip portion 102 helps to lower the center of gravity of the power tool, thereby improving the stability of the power tool when placed vertically and reducing the workload of the user operating the power tool.

[0131] In some embodiments, the circuit board 600 is nearly parallel to the bottom surface of the extension 103. The power tool is stored vertically, and in this vertical storage state, the bottom surface of the extension 103 abuts against the placement plane. Setting the circuit board 600 and the bottom surface of the extension 103 nearly parallel helps improve the stability of the circuit board 600 in the vertical storage state, lowers the center of gravity as much as possible, and also makes the circuit board 600 easier to assemble. The wires on the circuit board 600 can smoothly pass through the grip 102 to the motor 200.

[0132] Continue to refer to Figure 2 As shown, the power tool also includes a speed control plate assembly 800, which is electrically connected to the circuit board 600 and is disposed at the rear end of the motor housing 101. The speed control plate assembly 800 is used to detect speed adjustment operations and output speed setting commands to the circuit board 600. In some embodiments, the speed control plate assembly 800 is disposed at the rear end of the motor 200 along a first direction a. The speed control plate assembly 800 disposed at the rear end of the motor housing 101 is convenient for user operation and offers high operability.

[0133] Continue to refer to Figure 5 As shown, the power tool also includes a lighting assembly 900, which is disposed in the housing 100. The lighting assembly 900 improves visibility in the working environment, making the power tool suitable for working in poor lighting conditions, thus increasing its applicability and reducing the difficulty of operation. The lighting assembly 900 is electrically connected to a battery pack 300, which supplies power to the lighting assembly 900.

[0134] In some embodiments, the lighting assembly 900 includes a first light 910 and / or a second light 920. The first light 910 is located on the lower side of the motor housing 101 and near the foremost point, and is used to emit light in front of the power tool. The second light 920 is located on the upper side of the extension 103 and near the foremost point, and is used to emit light diagonally upwards towards the power tool. The first light 910 and the second light 920 work together to improve the lighting effect. In one specific embodiment, both the first light 910 and the second light 920 are LED lights. Of course, in other embodiments, the lighting assembly 900 may also include one or more lights.

[0135] The power tool also includes a heat dissipation structure to improve its heat dissipation performance. In some embodiments, a heat dissipation vent 180 is formed at the bearing housing 160 of the power tool. The opening direction of the heat dissipation vent 180 is parallel to the first axis p, and the heat generated by the motor 200 is dissipated outward by the heat dissipation vent 180. The heat dissipation vent 180 is a concealed vent, and no vent is provided on the housing 100. This arrangement can prevent foreign objects from entering the motor 200. Specifically, the motor 200 and the circuit board 600 are the main heat-generating components, and no vents are provided on the housing 100 at the corresponding locations of the motor 200 and the circuit board 600. In addition, in the embodiments of this application, heat dissipation is achieved not only by utilizing the concealed vent, but also by utilizing the rotation of the counterweight unit 430. The rotation of the counterweight unit 430 can agitate the airflow, thereby carrying away some heat. The combination of the two methods results in a better heat dissipation effect.

[0136] It should be noted that if the power tool is a sander, since the overall power of the sander is low and its operating conditions represent a short usage time, the concealed heat dissipation vent 180 can meet the heat dissipation requirements under short usage time. With sufficient heat dissipation time, the machine housing 100 can be without vents in appearance. This ensures heat dissipation while reducing the entry of sanding dust and foreign objects, making the housing 100 more rigid, the fanless noise lower, the head shell 1011 shorter in the axial direction, and the starting inertia smaller.

[0137] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that the above embodiments do not limit this application in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of this application.

Claims

1. A power tool, characterized in that, include: The housing (100) includes a motor housing (101) extending along a first direction a, a gripping portion (102) extending along a second direction b, and an extension portion (103), wherein the extension portion (103) is disposed at one end of the gripping portion (102) away from the motor housing (101), and the angle m between the first direction a and the second direction b is greater than or equal to 80° and less than or equal to 150°; The motor (200) is disposed inside the motor housing (101), and the motor (200) includes a stator (201), a rotor (202) and a motor shaft (203). A battery pack (300) is detachably mounted on the extension (103) for providing electrical energy to drive the motor (200) to rotate; An eccentric rotating assembly (400) is coupled to the motor (200) and driven to rotate by the motor shaft (203). The eccentric rotating assembly (400) includes a working head mounting part (420). The working head (500) is installed in the working head mounting part (420) and rotates eccentrically with the rotation of the eccentric rotation assembly (400); The circuit board (600) is housed in the inner space (1031) formed by the extension (103) and is electrically connected to the battery pack (300) and the motor (200). It is used to convert the electrical energy output by the battery pack (300) into the input electrical energy of the motor (200) and to control the operating state of the motor (200).

2. The power tool according to claim 1, characterized in that, The motor housing (101) forms a sleeve interface (104) along the first direction a for partially covering the eccentric rotating assembly (400).

3. The power tool according to claim 2, characterized in that, The power tool also includes a socket unit (700) connected to the socket interface (104) and together with the socket interface (104) covering the eccentric rotating assembly (400).

4. The power tool according to claim 1, characterized in that, The power tool also includes a speed control board assembly (800), which is electrically connected to the circuit board (600) and is located at the rear end of the motor housing (101). It is used to detect speed control operations and output speed setting commands to the circuit board (600).

5. The power tool according to claim 1, characterized in that, The housing (100) includes a first housing (110) and a second housing (120). The first housing (110) and the second housing (120) are symmetrical with respect to a first plane Q. The first plane Q is a plane formed by the first axis p of the motor shaft (203) and the second axis q of the grip (102).

6. The power tool according to claim 5, characterized in that, The first housing (110) and the second housing (120) are connected by a plurality of fasteners (130), and the extension (103) is connected by an embedded locking piece (140).

7. An electric tool, comprising: The housing (100) includes a motor housing (101) and a grip (102). The motor (200) is disposed inside the motor housing (101), and the motor (200) includes a stator (201), a rotor (202) and a motor shaft (203). A battery pack (300) is used to provide electrical energy to drive the motor (200) to rotate; An eccentric rotating assembly (400) is coupled to the motor (200) and driven to rotate by the motor shaft (203). The eccentric rotating assembly (400) includes a working head mounting part (420). The working head (500) is installed in the working head mounting part (420) and rotates eccentrically with the rotation of the eccentric rotation assembly (400); Its features are, The housing (100) also includes an extension (103) disposed on the side of the grip (102) away from the motor housing (101); The extension (103) includes a battery pack mating structure (150) for fixing the battery pack (300) to the extension (103), and the volume of the battery pack (300) extending into the inner space (1031) of the grip (102) is less than 10% of the total volume of the battery pack (300).

8. The power tool according to claim 7, characterized in that, The battery pack mating structure (150) adopts a guide rail structure (151) for the battery pack (300) to slide into the third direction c.

9. The power tool according to claim 8, characterized in that, The guide rail structure (151) is embedded in the extension part (103). After the battery pack (300) is assembled to the extension part (103), the upper surface of the battery pack (300) is located above the bottom surface of the extension part (103).

10. The power tool according to claim 7, characterized in that, The battery pack (300) is symmetrical with respect to the first plane Q. After the battery pack (300) is installed on the extension (103), the first axis p of the motor shaft (203) is located on the first plane Q.

11. The power tool according to claim 7, characterized in that, After the battery pack (300) is inserted into the extension (103), the shortest distance L1 between the front end of the battery pack (300) and the plane where the working head (500) is located is greater than 10mm.

12. The power tool according to claim 7, characterized in that, The center of gravity G0 of the battery pack (300) is closer to the working head (500) relative to the grip (102).

13. An electric tool, comprising: The housing (100) includes a motor housing (101) extending along a first direction a, a grip portion (102) extending along a second direction b, and an extension portion (103) disposed at one end of the grip portion (102) away from the motor housing (101); The motor (200) is disposed inside the motor housing (101), and the motor (200) includes a stator (201), a rotor (202) and a motor shaft (203). A battery pack (300) is detachably mounted on the extension (103) for providing electrical energy to drive the motor (200) to rotate; An eccentric rotating assembly (400) is coupled to the motor (200) and driven to rotate by the motor shaft (203). The eccentric rotating assembly (400) includes a working head mounting part (420). The working head (500) is installed in the working head mounting part (420) and rotates eccentrically with the rotation of the eccentric rotation assembly (400); Its features are, After the battery pack (300) is assembled to the extension (103), the center of gravity G2 of the power tool is located within the single-hand grip range corresponding to the grip (102).

14. The power tool according to claim 13, characterized in that, The first axis p of the motor shaft (203) and the second axis q of the grip (102) form a first plane Q, and the center of gravity G2 of the power tool is located in the first plane Q.

15. The power tool according to claim 14, characterized in that, The upper end of the grip (102) is provided with a trigger (1000). In the first plane Q, the center of gravity G2 of the power tool is located between the front end of the trigger (1000) and the back end of the power tool in the first direction a. The center of gravity G2 of the power tool is located between the lower end of the trigger (1000) and the upper end of the extension (103) in the second direction b.

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