Charging bottom cover assembly and electric toothbrush

Abstract

The utility model relates to the field of electric toothbrushes, and provides a charging bottom cover assembly and an electric toothbrush. The charging bottom cover assembly comprises a base and a bottom cover, the base is fixedly arranged at the bottom of the handle body, a first clamping groove and a second clamping groove are formed in the base in a penetrating mode, and the charging assembly is suitable for being installed in the second clamping groove; the bottom cover comprises a first cover body and a second cover body, the first cover body is arranged at the top of the second cover body, a connecting part is arranged on the first cover body and movably connected with the first clamping groove, a buckling groove is formed in the second cover body, a telescopic air hole is formed in the position, corresponding to the buckling groove, of the first cover body, and the telescopic air hole can be automatically opened and closed so as to exhaust air between the base and the bottom cover. The electric toothbrush comprises a charging bottom cover assembly. The telescopic air hole is formed in the first cover body of the bottom cover, the telescopic air hole can be automatically opened and closed, residual air between the base and the bottom cover is effectively exhausted, it is ensured that the bottom cover and the base are tightly attached, and therefore stable installation is achieved, and the shaking problem is avoided.

Description

Technical Field

[0001] This utility model relates to the field of electric toothbrushes, and further to a charging bottom cover assembly and an electric toothbrush. Background Technology

[0002] Electric toothbrushes typically have a charging unit on their base. To ensure the base is stable and protect the charging unit, a bottom cover is needed. However, the base of existing electric toothbrushes is usually located inside the toothbrush housing. This makes it easy for air to remain between the bottom cover and the base when pressing the bottom cover upwards. This air residue can make the pressing process less smooth and may prevent the bottom cover from fitting completely, ultimately affecting its flatness and causing the electric toothbrush to wobble when placed on the ground. Utility Model Content

[0003] To address the aforementioned technical problems, the purpose of this utility model is to provide a charging bottom cover assembly and an electric toothbrush. The first cover of the bottom cover is provided with a telescopic vent hole, which can automatically open and close to effectively expel residual air between the base and the bottom cover, ensuring that the bottom cover and the base fit tightly together, thereby achieving stable installation and avoiding shaking.

[0004] To achieve the above objectives, this utility model provides a charging bottom cover assembly, including a base and a bottom cover. The base is fixedly disposed at the bottom of the handle body, and a first slot and a second slot are provided through the base. The second slot is suitable for installing a charging component.

[0005] The bottom cover includes a first cover body and a second cover body. The first cover body is disposed on top of the second cover body. The first cover body is provided with a connecting part, which is movably connected to the first slot. The second cover body is provided with a buckle groove. The first cover body is provided with a telescopic vent hole at the corresponding position of the buckle groove. The telescopic vent hole can be automatically opened and closed to expel air between the base and the bottom cover.

[0006] In some embodiments, the first cover is made of soft rubber, and the first cover has a first bottom wall and a second bottom wall at the bottom of the telescopic vent.

[0007] When there is no air between the bottom cover and the base, the first bottom wall and the second bottom wall are pressed tightly against each other and the telescopic vent is closed; when there is air between the bottom cover and the base, the first bottom wall and the second bottom wall are moved away from each other and the telescopic vent is opened.

[0008] In some embodiments, the bottom of the first cover is provided with an annular groove, the first bottom wall is disposed on the outer ring of the annular groove, and the second bottom wall is disposed on the inner ring of the annular groove;

[0009] The second cover has an annular protrusion on its top, and the annular protrusion is adapted to abut against the annular groove.

[0010] When there is no air between the bottom cover and the base, the first bottom wall is in close contact with the annular protrusion and closes the telescopic vent; when there is air between the bottom cover and the base, the first bottom wall moves away from the annular protrusion and opens the telescopic vent.

[0011] In some embodiments, the second cover is made of a rigid material, and the first cover and the second cover are made by two-color injection molding. The bottom of the first cover is provided with a plurality of contact grooves, and the top of the second cover is provided with a plurality of contact posts, the contact posts being adapted to be disposed in the contact grooves.

[0012] In some embodiments, the connecting part is provided with a first connecting block, the slot of the first slot is provided with a second connecting block, the outer wall of the first connecting block is provided with a guide wall, the guide wall extends obliquely towards the side close to the central axis of the connecting part along the insertion direction of the connecting part, the connecting part is adapted to be guided into the first slot along the guide wall, and the bottom of the first connecting block and the top of the second connecting block are adapted to abut against each other.

[0013] In some embodiments, the guide wall is also provided with a plurality of guide protrusions spaced apart in the circumferential direction, and the guide protrusions also extend obliquely towards the side closer to the central axis of the connecting part along the insertion direction of the connecting part.

[0014] In some embodiments, a battery holder is also provided on the inner side of the handle body, the battery holder is fixedly disposed above the base, and the base is adapted to be snapped together with the battery holder.

[0015] In some embodiments, the battery holder is further provided with a first clamping block, and a sealing sleeve is fitted at the end of the first slot away from the bottom cover. The sealing sleeve is disposed between the first clamping block of the battery holder and the base.

[0016] In some embodiments, the battery holder is provided with a second clamping block, and the charging component is abutted between the second clamping block and the second slot;

[0017] The first cover is also provided with a sealing part, which is adapted to seal the connection of the charging component.

[0018] According to another aspect of this application, an electric toothbrush is further provided, including any of the charging base cover assemblies of the above preferred embodiments.

[0019] Compared with the prior art, the charging base cover assembly and electric toothbrush provided by this utility model have at least one of the following beneficial effects:

[0020] 1. The first cover of the bottom cover is provided with a telescopic vent hole. The telescopic vent hole can open and close automatically to effectively expel residual air between the base and the bottom cover, ensuring that the bottom cover and the base fit tightly, thereby achieving stable installation and avoiding shaking problems.

[0021] 2. The automatic opening and closing function of the telescopic vent is achieved through the first cover made of soft rubber material. It does not require a complex mechanical structure, has good elasticity and durability, and can withstand multiple opening and closing operations, thus extending the service life of the telescopic vent. Moreover, the first and second bottom walls at the bottom of the telescopic vent can effectively reduce the thickness of the first cover at the telescopic vent. The thinner first and second bottom walls can respond to pressure changes more quickly, allowing the telescopic vent to open or close rapidly when needed, thus improving the overall response speed and efficiency.

[0022] 3. The first bottom wall and the second bottom wall are located on both sides of the annular protrusion. The first bottom wall is close to or away from the annular protrusion to open and close the telescopic vent. When there is no air between the bottom cover and the base, the end of the first bottom wall near the annular protrusion is relatively far away from the buckle groove. At this time, the first bottom wall is located inside the second cover, which can effectively achieve a sealing effect, prevent impurities from entering, and the telescopic vent is not visible on the bottom cover, making it more aesthetically pleasing. When there is air between the bottom cover and the base, the end of the first bottom wall away from the annular protrusion enters the buckle groove area to realize the connection between the buckle groove and the telescopic channel, which facilitates the discharge of gas.

[0023] 4. The guide wall extends inclined towards the side closer to the central axis of the connecting part along the insertion direction of the connecting part, so that the first connecting block can be guided into the first slot more smoothly, reducing the resistance during assembly and improving the assembly efficiency; through the mutual abutment of the first connecting block and the second connecting block, it can effectively prevent the bottom cover from detaching from the base due to external force, ensuring the firmness of the bottom cover and the base during use. Attached Figure Description

[0024] The preferred embodiments will be described below in a clear and easy-to-understand manner, in conjunction with the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages and implementation methods of this utility model.

[0025] Figure 1 This is a cross-sectional view of a charging bottom cover assembly;

[0026] Figure 2 This is a structural diagram of the bottom cover;

[0027] Figure 3 It is a cross-sectional view of the expansion and contraction ventilation holes;

[0028] Figure 4 This is the bottom view of the first cover.

[0029] Figure 5 This is a top view of the second cover.

[0030] Figure 6 This is a structural diagram of the first connecting block.

[0031] Explanation of icon numbers:

[0032] Base 4, first slot 41, second connecting block 411, sealing sleeve 412, second slot 42, charging component 421.

[0033] Bottom cover 5, first cover body 51, connecting part 511, first connecting block 5111, guide wall 5112, guide protrusion 5113, telescopic vent 512, first bottom wall 5121, second bottom wall 5122, annular groove 513, contact groove 514, sealing part 515, second cover body 52, buckle groove 521, annular protrusion 522, contact post 523.

[0034] Battery holder 6, first clamping block 61, second clamping block 62. Detailed Implementation

[0035] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the specific implementation methods of this utility model will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of this utility model. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0036] To keep the drawings concise, each figure only schematically shows the parts relevant to the utility model, and these do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of the components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0037] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0038] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0039] Furthermore, in the description of this application, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance. It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of this utility model. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

[0040] refer to Figure 1 and Figure 2 This application provides a charging bottom cover assembly, including a base 4 and a bottom cover 5. The base 4 is fixedly disposed at the bottom of the handle body. A first slot 41 and a second slot 42 are provided through the base 4. The second slot 42 is suitable for installing a charging component 421. The bottom cover 5 includes a first cover body 51 and a second cover body 52. ​​The first cover body 51 is disposed on the top of the second cover body 52. ​​The first cover body 51 is provided with a connecting part 511, which is movably connected to the first slot 41. The second cover body 52 is provided with a fastening groove 521. The first cover body 51 is provided with a telescopic vent 512 at the corresponding position of the fastening groove 521. The telescopic vent 512 can automatically open and close to expel air between the base 4 and the bottom cover 5.

[0041] In this embodiment, the first cover 51 of the bottom cover 5 is provided with a telescopic vent 512. The telescopic vent 512 can open and close automatically to effectively discharge the residual air between the base 4 and the bottom cover 5, ensuring that the bottom cover 5 and the base 4 fit tightly together, thereby achieving stable installation and avoiding shaking problems.

[0042] Specifically, the base 4 is fixedly installed at the bottom of the electric toothbrush handle body, and has a first slot 41 and a second slot 42. The second slot 42 is used to install the charging component 421, ensuring the stability and safety of the charging component 421. The first slot 41 is used to connect the connecting part 511 of the bottom cover 5. The bottom cover 5 consists of a first cover body 51 and a second cover body 52, with the first cover body 51 located on top of the second cover body 52. ​​The first cover body 51 has a connecting part 511, which is movably connected to the first slot 41 on the base 4, facilitating the installation and removal of the bottom cover 5. The second cover body 52 has a latching groove 521, which is used to cooperate with the structure of the first cover body 51 to enhance overall stability. The first cover 51 has a telescopic vent 512 at the corresponding position of the slot 521. The telescopic vent 512 can open and close automatically. Its main function is to expel the air between the base 4 and the bottom cover 5 during the installation of the bottom cover 5, thereby ensuring that the bottom cover 5 and the base 4 fit tightly together and avoiding uneven installation caused by residual air. It can effectively improve the installation accuracy of the bottom cover 5 and also effectively prevent the electric toothbrush from shaking due to unevenness of the bottom cover 5 during use.

[0043] It is worth noting that the opening and closing methods of the telescopic vent 512 are diverse, and this application does not impose further limitations. For example, a flexible waterproof component, such as silicone or rubber, can be provided at the opening of the telescopic vent 512. This flexible waterproof component can automatically open and close the vent under pressure, while preventing moisture from entering. Alternatively, a telescopic structure, such as an elastic ring or spring, can be designed around the telescopic vent 512. When the bottom cover 5 contacts the base 4, the telescopic structure automatically compresses, expelling air, and returns to its original shape after being released. A layer of elastic waterproof and breathable membrane can also be installed inside the telescopic vent 512. When the bottom cover 5 contacts the base 4 and generates pressure, the elastic membrane bulges outward, opening the vent and expelling internal air; when the pressure is released, the elastic membrane returns to its original shape, and the vent automatically closes. The first cover 51 is made of soft rubber; a hole can even be directly punched in the first cover 51, and this hole can expand and contract according to pressure.

[0044] Further, refer to Figures 3 to 5 The first cover 51 is made of soft rubber. The first cover 51 has a first bottom wall 5121 and a second bottom wall 5122 at the bottom of the telescopic vent 512. When there is no air between the bottom cover 5 and the base 4, the first bottom wall 5121 and the second bottom wall 5122 are tightly attached to each other and the telescopic vent 512 is closed. When there is air between the bottom cover 5 and the base 4, the first bottom wall 5121 and the second bottom wall 5122 are far apart and the telescopic vent 512 is opened.

[0045] In this embodiment, the automatic opening and closing function of the telescopic vent 512 is achieved through the first cover 51 made of soft rubber material. It does not require a complex mechanical structure, has good elasticity and durability, and can withstand multiple opening and closing operations, thus extending the service life of the telescopic vent 512. Moreover, the first bottom wall 5121 and the second bottom wall 5122 are provided at the bottom of the telescopic vent 512, which can effectively reduce the thickness of the first cover 51 at the telescopic vent 512. The thinner first bottom wall 5121 and the second bottom wall 5122 can respond to pressure changes more quickly, so that the telescopic vent 512 can be opened or closed quickly when needed, improving the overall response speed and efficiency.

[0046] Specifically, the first cover 51 is made of soft rubber, and it has a first bottom wall 5121 and a second bottom wall 5122 at the bottom of the telescopic vent 512. When there is no air between the bottom cover 5 and the base 4, the first bottom wall 5121 and the second bottom wall 5122 are tightly pressed together, thereby closing the telescopic vent 512 and preventing external dust and moisture from entering. When there is air between the bottom cover 5 and the base 4, the air pressure will cause the first bottom wall 5121 and the second bottom wall 5122 to move away from each other, thereby opening the telescopic vent 512, expelling the internal air, ensuring a tight fit between the bottom cover 5 and the base 4, and avoiding uneven installation caused by residual air. This not only improves the installation accuracy of the bottom cover 5, but also effectively prevents the electric toothbrush from shaking during use due to unevenness of the bottom cover 5. The first bottom wall 5121 and the second bottom wall 5122 are located at the bottom of the telescopic vent 512, which can effectively reduce the thickness of the first cover 51 at the telescopic vent 512. The thinner first bottom wall 5121 and the second bottom wall 5122 can respond to pressure changes more quickly, so that the telescopic vent 512 can be opened or closed quickly when needed, improving the overall response speed and efficiency.

[0047] Preferably, refer to Figure 4 and Figure 5 The bottom of the first cover 51 is provided with an annular groove 513, the first bottom wall 5121 is provided on the outer ring of the annular groove 513, and the second bottom wall 5122 is provided on the inner ring of the annular groove 513; the top of the second cover 52 is provided with an annular protrusion 522, which is adapted to abut against the annular groove 513; when there is no air between the bottom cover 5 and the base 4, the first bottom wall 5121 is in close contact with the annular protrusion 522 and the telescopic vent 512 is closed; when there is air between the bottom cover 5 and the base 4, the first bottom wall 5121 is away from the annular protrusion 522 and the telescopic vent 512 is opened.

[0048] In this embodiment, the first bottom wall 5121 and the second bottom wall 5122 are located on both sides of the annular protrusion 522. The first bottom wall 5121 is close to or away from the annular protrusion 522 to open and close the telescopic vent 512. When there is no air between the bottom cover 5 and the base 4, the end of the first bottom wall 5121 near the annular protrusion is relatively far away from the buckle groove 521. At this time, the first bottom wall 5121 is located inside the second cover 52, which can effectively achieve a sealing effect and prevent impurities from entering. Moreover, the telescopic vent 512 is not visible on the bottom cover 5, making it more aesthetically pleasing. When there is air between the bottom cover 5 and the base 4, the end of the first bottom wall 5121 away from the annular protrusion enters the range of the buckle groove 521 to realize the connection between the buckle groove 521 and the telescopic channel, which facilitates the discharge of gas.

[0049] Specifically, the annular groove 513 and the annular protrusion 522 ensure a tighter fit between the bottom cover 5 and the base 4. When there is no air between the bottom cover 5 and the base 4, the end of the first bottom wall 5121 near the annular protrusion is relatively far from the latch groove 521. At this time, the telescopic vent 512 is completely hidden between the first cover body 51 and the second cover body 52, and its existence is not visible, making the surface of the bottom cover 5 smoother and more aesthetically pleasing. At the same time, the first bottom wall 5121 covering the space between the first cover body 51 and the second cover body 52 also effectively achieves a sealing effect, preventing dust, moisture, and other impurities from entering the interior of the bottom cover 5, thereby protecting the charging component 421 and other internal structures. When there is air between the bottom cover 5 and the base 4, the end of the first bottom wall 5121 away from the annular protrusion enters the range of the buckle groove 521, realizing the connection between the buckle groove 521 and the telescopic vent 512, which facilitates the rapid discharge of air, improves ventilation efficiency, and also ensures a tight fit between the bottom cover 5 and the base 4, avoiding uneven installation caused by residual air, thereby improving the stability of the product and the user experience.

[0050] It is worth noting that the second cover 52 is made of rigid material. The first cover 51 and the second cover 52 are made of two-color injection molding. The rigid material of the second cover 52 ensures the overall structural strength and durability of the bottom cover 5, and can withstand various impacts and pressures in daily use. The bottom of the first cover 51 is also provided with several contact grooves 514, and the top of the second cover 52 is provided with several contact posts 523. The contact posts 523 are suitable for being set in the contact grooves 514, further increasing the contact area of ​​the first cover 51 and the second cover 52, making them fit more tightly and improving their connection strength.

[0051] Further, refer to Figure 6The connecting part 511 is provided with a first connecting block 5111, and the slot of the first slot 41 is provided with a second connecting block 411. The outer side wall of the first connecting block 5111 is provided with a guide wall 5112. The guide wall 5112 extends obliquely towards the side close to the central axis of the connecting part 511 along the insertion direction of the connecting part 511. The connecting part 511 is adapted to be inserted into the first slot 41 guided by the guide wall 5112, and the bottom of the first connecting block 5111 and the top of the second connecting block 411 are adapted to abut against each other.

[0052] In this embodiment, the guide wall 5112 extends inclined towards the side closer to the central axis of the connecting part 511 along the insertion direction of the connecting part 511, so that the first connecting block 5111 can be guided into the first slot 41 more smoothly, reducing the resistance during assembly and improving the assembly efficiency; through the mutual abutment of the first connecting block 5111 and the second connecting block 411, the bottom cover 5 can be effectively prevented from detaching from the base 4 due to external force, ensuring the firmness of the bottom cover 5 and the base 4 during use.

[0053] Specifically, the guide wall 5112 can automatically guide the first connecting block 5111 to insert into the second connecting block 411 inside the first slot 41. Even if there is a certain angular deviation during assembly, precise assembly can be achieved through the inclined surface of the guide wall 5112. After the first connecting block 5111 is inserted into the first slot 41, the first connecting block 5111 moves away from the second connecting block 411. When it is necessary to remove the bottom cover 5, the first connecting block 5111 is relatively close to the second connecting block 411, and the bottom of the first connecting block 5111 abuts against the second connecting block 411, so that the bottom cover 5 is always connected to the base 4. The guide wall 5112 is also provided with a number of guide protrusions 5113 at intervals around its circumference. The guide protrusions 5113 also extend inclinedly towards the side closer to the central axis of the connecting part 511 along the insertion direction of the connecting part 511. The guide protrusion 5113 reduces the contact area between the first connecting block 5111 and the second connecting block 411, thereby reducing friction during the insertion of the first connecting block 5111 into the first slot 41, resulting in smoother assembly. It also distributes pressure more evenly, reducing local stress concentration and improving structural durability. The guide protrusion 5113 not only reduces the contact area, but its location at the end of the guide wall 5112, flush with the end of the first connecting block 5111, increases the effective area of ​​the bottom of the first connecting block 5111, resulting in greater contact force between the two blocks, strengthening the connection and preventing loosening. The guide protrusion 5113 can be designed in a trapezoidal, triangular, or arc shape to better guide insertion. The inclination angle of the guide protrusion 5113 is generally between 10 and 30 degrees, and the top can be rounded or spherical to reduce friction during insertion. It is worth noting that the connection between the first cover 51 and the base 4 can also be achieved through other connection structures such as hanging ropes, as long as the first cover 51 can be movably connected to the base 4.

[0054] Further, refer to Figure 1 The handle body is also provided with a battery holder 6 on the inside. The battery holder 6 is fixedly set on the top of the handle body, and the base 4 is adapted to be snapped together with the battery holder 6.

[0055] Specifically, the snap-fit ​​connection method between the base 4 and the battery holder 6 will not be further described here. The battery holder 6 is also provided with a first clamping block 61, and a sealing sleeve 412 is fitted onto the end of the first slot 41 away from the bottom cover 5. The sealing sleeve 412 is abutted between the first clamping block 61 and the base 4 of the battery holder 6. The sealing sleeve 412 is sealed at the end of the first slot 41 away from the bottom cover 5, forming a sealed barrier to effectively prevent moisture and dust from entering from the first slot 41. Furthermore, its abutment between the first clamping block 61 and the base 4 of the battery holder 6 ensures that the sealing sleeve 412 will not shift or loosen during use, thereby improving the reliability of the sealing effect. The battery holder 6 is provided with a second clamping block 62, and the charging assembly 421 is abutted between the second clamping block 62 and the second slot 42; the first cover 51 is also provided with a sealing part 515, which is suitable for sealingly connecting the charging assembly 421. The sealing part 515 on the first cover 51 fits tightly with the charging component 421, forming a double sealing barrier. This further enhances the waterproof performance, ensuring that the charging component 421 is not affected by the external environment during use. It also provides additional physical protection for the charging component 421, preventing damage from external impacts or pressure. The second clamping block 62 firmly holds the charging component 421 against the second slot 42, ensuring that the charging component 421 is stable and reliable during use and will not loosen due to vibration or external force, thereby improving the product's service life.

[0056] Furthermore, this application provides an electric toothbrush including the charging base cover assembly of any of the above embodiments.

[0057] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of this utility model. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A charge sole cover assembly, characterized by, The utility model relates to a handle charging bottom cover assembly, including: The base is fixedly arranged at the bottom of the handle main body, and the first clamping groove and the second clamping groove are arranged through the base, and the second clamping groove is suitable for installing the charging assembly; The bottom cover includes the first cover body and the second cover body, the first cover body is arranged at the top of the second cover body, the first cover body is provided with the connecting part, the connecting part is movably connected with the first clamping groove, the second cover body is provided with the buckle groove, the first cover body is provided with the telescopic air hole at the corresponding position of the buckle groove, and the telescopic air hole can be automatically opened and closed to discharge the air between the base and the bottom cover.

2. The charging bottom cover assembly according to claim 1, wherein: The first cover body is made of soft rubber material, and the first cover body is provided with the first bottom wall and the second bottom wall at the bottom of the telescopic air hole; When there is no air between the bottom cover and the base, the first bottom wall and the second bottom wall are close to each other and close the telescopic air hole; when there is air between the bottom cover and the base, the first bottom wall and the second bottom wall are away from each other and open the telescopic air hole.

3. The charging bottom cover assembly according to claim 2, wherein: The first cover body is provided with an annular groove at the bottom, the first bottom wall is arranged at the outer circle of the annular groove, and the second bottom wall is arranged at the inner circle of the annular groove; The second cover body is provided with an annular protrusion at the top, and the annular protrusion is suitable for abutting against the annular groove; When there is no air between the bottom cover and the base, the first bottom wall is close to the annular protrusion and closes the telescopic air hole; when there is air between the bottom cover and the base, the first bottom wall is away from the annular protrusion and opens the telescopic air hole.

4. The charging bottom cover assembly according to claim 2, wherein: The second cover body is made of hard material, the first cover body and the second cover body are formed by double-color injection molding, the first cover body is further provided with a plurality of contact grooves at the bottom, and the second cover body is correspondingly provided with a plurality of contact columns at the top, and the contact columns are suitable for being arranged in the contact grooves.

5. The charging bottom cover assembly according to any one of claims 1-4, wherein: The connecting part is provided with a first connecting block, the slot of the first clamping groove is provided with a second connecting block, the outer side wall of the first connecting block is provided with a guide wall, the guide wall is inclinedly extended along the insertion direction of the connecting part to the side close to the central axis of the connecting part, the connecting part is suitable for being guided and inserted into the first clamping groove along the guide wall, and the bottom of the first connecting block and the top of the second connecting block are suitable for abutting against each other.

6. The charging bottom cover assembly according to claim 5, wherein: The guide wall is further provided with a plurality of guide protrusions at intervals in the circumferential direction, and the guide protrusions are also inclinedly extended along the insertion direction of the connecting part to the side close to the central axis of the connecting part.

7. The charging bottom cover assembly according to claim 5, wherein: The inside of the handle main body is further provided with a battery seat, the battery seat is fixedly arranged above the base, and the base is suitable for being buckled with the battery seat.

8. The charging bottom cover assembly according to claim 7, characterized in that, the battery holder is further provided with a first pressing block, and a sealing sleeve is further sleeved on the end of the first clamping groove away from the bottom cover, and the sealing sleeve is arranged between the first pressing block of the battery holder and the bottom seat.

9. The charging bottom cover assembly according to claim 7, characterized in that, the battery holder is provided with a second pressing block, and the charging assembly is arranged between the second pressing block and the second clamping groove; the first cover body is further provided with a sealing part, and the sealing part is suitable for sealingly connecting the charging assembly.

10. An electric toothbrush characterized by comprising: The charging bottom cover assembly comprises the charging bottom cover assembly according to any one of claims 1-9.

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