Electric toothbrush and handle

Abstract

The present disclosure relates to an electric toothbrush and a handle, the electric toothbrush comprising a handle and a brush head arranged on the handle, the handle comprising: a shell and a sensing assembly. A cavity is arranged in the shell; a driving motor and a motor housing are arranged in the cavity; the driving motor is provided with an output shaft extending along a first axis, and the output shaft is configured to be connected with the brush head; the driving motor is mounted in the cavity through the motor housing; the sensing assembly comprises a sensor and an elastic sheet abutting against the sensor; the elastic sheet is configured to extend along the first axis, and opposite ends of the elastic sheet are respectively marked as a first end and a second end; the first end is configured to be fixedly connected to the motor housing, and the second end is configured to be mounted in cooperation with the driving motor; wherein the output shaft is configured to drive the driving motor to move relative to the motor housing under the action of an external force, so that the elastic sheet is deformed; and the sensor is configured to perform force sensing based on a deformation amount of the elastic sheet.

Description

Technical Field

[0001] This disclosure relates to the field of oral hygiene technology, specifically to an electric toothbrush; this disclosure also relates to a handle. Background Technology

[0002] As living standards improve, people are becoming more aware of oral care, leading to a greater variety of oral hygiene tools on the market. Take electric toothbrushes as an example: the drive motor in the handle can cause the brush head to swing or vibrate. To better protect users' dental health and increase brushing comfort, sensors can be used to detect the brushing pressure and alert users when the pressure is too high.

[0003] In existing technologies, sensors are typically mounted on the output shaft of a drive motor and connected to the control board via circuit connectors. However, during operation, the output shaft moves along with the sensor, thus affecting the circuit connectors. For drive motors capable of large-angle rotation, or even 360° rotation of the output shaft, this mounting method is no longer suitable. Furthermore, mounting sensors on the output shaft is complex and difficult, and can easily lead to problems such as insensitive and inaccurate pressure sensing. Utility Model Content

[0004] This disclosure provides an electric toothbrush and handle to address the problems existing in the prior art.

[0005] According to a first aspect of this disclosure, an electric toothbrush is provided, including a handle and a brush head disposed on the handle, the handle comprising: The outer casing has a cavity; a drive motor and a motor housing are disposed in the cavity; the drive motor has an output shaft extending along a first axis, and the output shaft is configured to connect to the brush head; the drive motor is mounted in the cavity through the motor housing. A sensing assembly, comprising a sensor and an elastic sheet abutting against the sensor; the elastic sheet is configured to extend along a first axis, and the opposite ends of the elastic sheet are respectively referred to as a first end and a second end; the first end is configured to be fixedly connected to the motor housing, and the second end is configured to be installed in conjunction with the drive motor; The output shaft is configured to drive the drive motor to move relative to the motor housing under the action of an external force, thereby causing the elastic sheet to deform; the sensor is configured to sense the force based on the deformation of the elastic sheet.

[0006] In one embodiment of this disclosure, the elastic sheet is configured such that, during deformation, its connection point with the motor housing serves as the deformation fulcrum.

[0007] In one embodiment of this disclosure, the sensor is configured to be fixed on the elastic sheet at a position adjacent to the deformation fulcrum.

[0008] In one embodiment of this disclosure, the elastic sheet is configured to be located on the first direction side of the drive motor; the output shaft is configured to move in the first direction under the action of an external force to cause the elastic sheet to deform.

[0009] In one embodiment of this disclosure, the first end is configured to be away from the output shaft, and the second end is configured to be close to the output shaft; the drive motor is configured to apply a force to a position on the elastic sheet adjacent to the second end under the action of an external force, so as to deform the elastic sheet.

[0010] In one embodiment of this disclosure, a protrusion is provided on the first direction sidewall of the drive motor, the protrusion being configured to be pre-pressed onto the elastic sheet at a position adjacent to the second end; the output shaft is configured to drive the protrusion to move in the first direction under the action of an external force, so as to compress the elastic sheet to deform.

[0011] In one embodiment of this disclosure, a flexible sleeve is provided outside the drive motor, the flexible sleeve being configured to at least partially enclose the drive motor; the protrusion is provided on the flexible sleeve.

[0012] In one embodiment of this disclosure, the first end is configured to be away from the output shaft, and the second end is configured to be close to the output shaft; the drive motor is configured to apply a force to the second end under the action of an external force to deform the elastic sheet.

[0013] In one embodiment of this disclosure, the elastic sheet includes a connecting portion disposed at the second end, the connecting portion being configured to extend to connect with the drive motor; the drive motor is configured to drive the elastic sheet to deform via the connecting portion.

[0014] In one embodiment of this disclosure, the connecting portion is configured to extend along a second direction to connect with the drive motor, the second direction being opposite to the first direction; the drive motor is configured to drive the connecting portion to move in the first direction to cause the elastic sheet to deform.

[0015] In one embodiment of this disclosure, the connecting portion is configured to be fixedly connected to the side of the drive motor on which the output shaft is located; the connecting portion is provided with a clearance area, which is configured to allow clearance for the extension path of the output shaft.

[0016] In one embodiment of this disclosure, the drive motor is a servo motor.

[0017] In one embodiment of this disclosure, a control motherboard is further included; the control motherboard is configured to be located in the cavity and to be communicatively connected to the sensor; the control motherboard is configured to determine the pressure value applied to the output shaft based on the electrical signal output by the sensor; and when the pressure value is greater than a threshold, the control motherboard is configured to issue a warning signal.

[0018] In one embodiment of this disclosure, the brush head is configured to move the output axis away from the direction of the brush head under the action of an external force, so as to cause the elastic sheet to deform.

[0019] According to a second aspect of this disclosure, a handle is also provided, comprising: The housing has a cavity; a drive motor and a motor housing are disposed in the cavity; the drive motor has an output shaft extending along a first axis; the drive motor is mounted in the cavity through the motor housing. A sensing assembly, comprising a sensor and an elastic sheet abutting against the sensor; the elastic sheet is configured to extend along a first axis, and the opposite ends of the elastic sheet are respectively referred to as a first end and a second end; the first end is configured to be fixedly connected to the motor housing, and the second end is configured to be installed in conjunction with the drive motor; The output shaft is configured to drive the drive motor to move relative to the motor housing under the action of an external force, thereby causing the elastic sheet to deform; the sensor is configured to sense the force based on the deformation of the elastic sheet.

[0020] One beneficial effect of this disclosure is that, by setting an elastic plate that cooperates with the drive motor, the output shaft can drive the drive motor to move relative to the motor housing under the action of external force, thereby causing the elastic plate to deform. The sensor set on the elastic plate can sense the force based on the deformation of the elastic plate. This breaks through the design limitation of "the sensor moving directly with the output shaft" in the prior art, effectively avoiding the entanglement of the circuit connectors when the output shaft moves, allowing the handle to be adapted to more types of drive motors, and greatly expanding the scope of application. In addition, compared with the high-precision installation process of mounting the sensor on the output shaft, the cooperative installation of the elastic plate and the drive assembly in this disclosure is easier to operate, thereby simplifying the installation process and reducing production difficulty and cost.

[0021] Other features and advantages of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0022] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the present disclosure and, together with their description, serve to explain the principles of the present disclosure.

[0023] Figure 1 This is a schematic diagram of a handle structure provided in an embodiment of the present disclosure; Figure 2 This is a cross-sectional view of an electric toothbrush provided in an embodiment of this disclosure; Figure 3 This is an exploded view of an electric toothbrush provided in an embodiment of this disclosure; Figure 4 This is a partial cross-sectional view of a driving component and a sensing component provided in an embodiment of this disclosure; Figure 5 This is a schematic diagram of the structure of the driving component and the sensing component provided in an embodiment of the present disclosure; Figure 6 This is a partial cross-sectional view of a handle provided in an embodiment of this disclosure; Figure 7 This is a schematic diagram of a cover plate structure provided in one embodiment of the present disclosure; Figure 8 This is a partial structural diagram of a driving component and a sensing component provided in an embodiment of the present disclosure; Figure 9 This is a schematic diagram of the cover plate and sensing component structure provided in an embodiment of the present disclosure; Figure 10 This is a schematic diagram of a cover plate structure provided in another embodiment of this disclosure; Figure 11 This is a structural schematic diagram of the cover plate from another angle according to another embodiment of this disclosure; Figure 12 This is a schematic diagram of the structure of the driving component and the sensing component provided in another embodiment of the present disclosure; Figure 13 This is a partial cross-sectional view of the handle provided in another embodiment of this disclosure.

[0024] Figures 1 to 13 The one-to-one correspondence between the component names and the reference numerals in the figures is as follows: 100. Handle; 1. Housing; 10. Cavity; 2. Drive assembly; 21. Drive motor; 211. Output shaft; 22. Motor housing; 221. Cover plate; 23. Flexible sleeve; 231. Protrusion; 24. Elastic arm; 241. Fixed end; 242. Free end; 25. Connecting arm; 251. Limiting part; 252. Mating groove; 3. Sensing assembly; 31. Elastic sheet; 311. First end; 312. Second end; 313. Connecting part; 32. Sensor; 33. Circuit connector; 34. Fixing pin; 4. Control board; 5. Battery; 6. Soft rubber pad; 200. Brush head; 201. Brush bristles. Detailed Implementation

[0025] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0026] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0027] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0029] In this article, terms such as "up," "down," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, rather than to define the absolute position of these related parts.

[0030] In this article, "first," "second," etc., are used only to distinguish one another, and not to indicate degree of importance, order, or prerequisite for each other.

[0031] In this document, terms such as “equal” and “same” are not strict mathematical and / or geometric limitations, but also include errors that are understandable to those skilled in the art and permissible in manufacturing or use.

[0032] This disclosure provides an electric toothbrush and a handle, wherein the electric toothbrush includes the handle. The specific structure and working principle of the electric toothbrush provided by this disclosure will be described in detail below with reference to the accompanying drawings, and the specific structure and working principle of the handle provided by this application will also be described at the same time.

[0033] This disclosure provides an electric toothbrush, with reference to... Figures 1 to 3 The electric toothbrush includes a handle 100 and a brush head 200. The handle 100 includes a housing 1, a drive assembly 2, and a sensing assembly 3. The housing 1 is configured for comfortable gripping, allowing the user to hold the housing 1 and operate the electric toothbrush for oral cleaning. Figure 2 As shown, a cavity 10 is provided in the outer casing 1, which is used to accommodate various components in the handle 100.

[0034] like Figure 2 As shown, the drive component 2 is disposed in the cavity 10, specifically, as... Figure 3As shown, the drive assembly 2 includes a drive motor 21 and a motor housing 22. The drive motor 21 has an output shaft 211 extending along the first axis. Figure 4 In the view orientation, the horizontally extending X-axis is the first axis. The output shaft 211 can be used to connect the brush head 200 of the electric toothbrush. Specifically, the brush head 200 is located at the end of the handle 100 and is configured to connect to the output shaft 211. The brush head 200 may include bristles 201, which are formed by multiple bristle clusters and are used to contact the teeth to achieve the brushing function. The output shaft 211 of the drive motor 21 can drive the brush head 200 to oscillate, thereby improving the cleaning effect.

[0035] In one specific embodiment of this disclosure, the drive motor 21 can be a servo motor, which can control the swing speed of the output shaft 211 with very accurate position control. This allows the output shaft 211 to reciprocate forward and reverse by a predetermined angle around the first axis, thereby outputting swing power to drive the brush head 200 to vibrate. Users can easily clean toothbrush dirt without swinging their wrists while brushing their teeth, ensuring a cleaning effect.

[0036] The drive motor 21 is mounted in the cavity 10 via a motor housing 22. Specifically, the motor housing 22 may include a mounting bracket disposed inside the outer casing 1, which can be used to mount various components in the cavity 10. In one embodiment of this disclosure, refer to... Figure 2 and Figure 8 The motor housing 22 may further include a cover plate 221 mounted on a mounting bracket. The cover plate 221 and at least a portion of the mounting bracket enclose a first mounting space for accommodating the drive motor 21. The cover plate 221 can be fixed to the mounting bracket by a plurality of screws, and together with the mounting bracket, the drive motor 21 is mounted within the first mounting space. (Reference) Figure 2 and Figure 3 On the side of the mounting bracket that is relatively far from the output shaft 211, a second mounting space for accommodating the battery 5 can also be provided. The first mounting space can be connected to the second mounting space so that the battery 5 in the second mounting space can supply power to the drive motor 21 in the first mounting space.

[0037] The sensing component 3 includes a sensor 32 and an elastic sheet 31 that abuts against the sensor 32. The sensor 32 can be disposed on the elastic sheet 31. The elastic sheet 31 has outstanding elastic properties and sufficient hardness, thereby simultaneously meeting the core requirements of elastic transmission of external force and hardness to ensure stable deformation. The elastic sheet 31 can be made of materials such as stainless steel, titanium alloy, plastic, or glass fiber reinforced nylon. At least one end of the elastic sheet 31 is configured to be installed in conjunction with the drive component 2. The output shaft 211 is configured to indirectly drive the elastic sheet 31 to deform under the action of external force. The sensor 32 is configured to sense the force based on the deformation of the elastic sheet 31. The output shaft 211 will move under the action of external force, and during the movement, it will drive the elastic sheet 31 to deform. The sensor 32 can determine the magnitude of the force on the output shaft 211 based on the deformation of the elastic sheet 31. The sensor 32 can be any type of sensor 32 capable of sensing the deformation of the elastic sheet 31, such as a strain gauge sensor, piezoelectric sensor, capacitive sensor, or displacement sensor. This disclosure does not limit the specific type of sensor 32.

[0038] In one embodiment of this disclosure, the brush head 200 is configured to drive the output shaft 211 to move away from the brush head 200 under the action of an external force, thereby causing the elastic sheet 31 to deform. Figure 2 As shown, a first direction S1 and a second direction S2 are defined. The bristles 201 extend towards the second direction S2. When the user brushes their teeth, the front of the brush head 200 (i.e., the side with the bristles 201) contacts the user's teeth, thereby causing the output shaft 211 to be subjected to a force towards the first direction S1, which in turn causes the output shaft 211 to move away from the brush head 200. It can be understood that the greater the force the user uses when brushing their teeth, the greater the range of motion of the output shaft 211. The output shaft 211 will cause the elastic sheet 31 to undergo a larger deformation, and the sensor 32 can detect that the current brushing force is relatively large.

[0039] To better protect users' dental health and increase brushing comfort, a reminder needs to be issued when the sensor detects excessive brushing force. In one embodiment of this disclosure, see [link to relevant documentation]. Figure 2 and Figure 3 The handle 100 also includes a control board 4, which is configured to be located within the cavity 10 and to communicate with the sensor 32. Specifically, see reference... Figure 8 The sensing component 3 also includes a circuit connector 33, which can be an FPC board. The circuit connector 33 is used to connect the sensor 32 to the control motherboard 4. It can transmit the information detected by the sensor 32 to the control motherboard 4 in the form of an electrical signal. The circuit connector 33 can be soldered onto the control motherboard 4.

[0040] The control motherboard 4 can be fixed on a mounting bracket and connected to various components in the handle 100, thereby controlling the coordinated operation of these components. For example, see reference... Figure 3 and Figure 5 In the first axial direction, a control circuit can be provided on the end of the drive motor 21 away from the output shaft 211. The control main board 4 can be soldered together with the control circuit located on the drive motor 21 to control the drive motor 21 to turn on or off. In addition, the handle 100 can also be provided with a display screen for displaying visual information, a light-emitting element for displaying light signals, etc. The control main board 4 can communicate with the display screen, light-emitting element, etc. respectively to control the visual information content displayed on the display screen and control the turning on or off of the light-emitting element.

[0041] The control board 4 is configured to determine the pressure value applied to the output shaft 211 based on the electrical signal output by the sensor 32. When the pressure value exceeds a threshold, the control board 4 is configured to issue a prompt signal. Specifically, this prompt signal can be displayed on the screen, activated by turning on a light, or caused by vibration of the control handle 100. A pressure value exceeding the threshold indicates that the user is brushing too hard. To remind the user to reduce brushing force, the control board 4 issues a prompt signal. The user can notice the prompt signal and adjust the brushing force in time, which is beneficial to the health of teeth and periodontal tissues.

[0042] In one specific embodiment of this disclosure, the complete process of force sensing by the sensing component 3 is as follows: ① External force transmission stage: When the user uses the electric toothbrush to brush their teeth, the brush head 200 will transmit the reaction force to the output shaft 211 of the drive motor 21. Since the output shaft 211 cooperates with the elastic sheet 31 through the drive component 2, the output shaft 211 will drive the drive component 2 to produce a small displacement after being subjected to force, which will indirectly push the elastic sheet 31 to deform (such as the middle area of ​​the elastic sheet 31 bending downward, or one end of the elastic sheet 31 bending relative to the other end).

[0043] ② Force sensing stage: Sensor 32 is set in the deformation sensitive area of ​​elastic sheet 31. Taking sensor 32 as an optical displacement sensor as an example: the position of light reflected back to the sensor is fixed. When elastic sheet 31 deforms, the position of the reflected light will also change. Sensor 32 can calculate the specific deformation of elastic sheet 31 by calculating the offset of the reflected light. Sensor 32 can convert the deformation into a corresponding voltage signal and transmit it to the control board 4 through circuit connector 33.

[0044] ③ Signal processing stage: After the weak voltage signal is processed by the amplification circuit and the filtering circuit, it is transmitted to the analog-to-digital converter of the control motherboard 4. The analog-to-digital converter converts the analog voltage signal into a digital signal, and then calculates the real-time pressure value of the output shaft 211 by combining the pre-calibrated correspondence between the deformation of the elastic sheet 31 and the pressure value of the output shaft 211.

[0045] ④ Closed-loop feedback stage: When the control motherboard 4 determines that the pressure value of the output shaft 211 exceeds the threshold, it will trigger an alert mechanism (such as display prompts, flashing lights, handle vibration, etc.) to prompt the user to reduce the brushing force. At the same time, after the external force on the output shaft 211 is reduced, the elastic sheet 31 can return to its original shape by its own elasticity, and the sensor 32 enters the next detection cycle.

[0046] This disclosure, by setting an elastic sheet 31 that is installed in conjunction with the drive assembly 2, allows the output shaft 211 to indirectly drive the elastic sheet 31 to deform under external force. The sensor 32, mounted on the elastic sheet 31, can sense the force based on the deformation of the elastic sheet 31. This overcomes the design limitation of the prior art where "the sensor 32 moves directly with the output shaft 211," effectively avoiding the pulling of the circuit connector 33 when the output shaft 211 moves. This allows the handle 100 to be adapted to more types of drive motors 21, greatly expanding its applicability. In addition, compared to the high-precision installation process of mounting the sensor 32 on the output shaft 211, the installation of the elastic sheet 31 and the drive assembly 2 in this disclosure is easier to operate, thereby simplifying the installation process and reducing production difficulty and cost.

[0047] Furthermore, the elastic sheet 31, as a force transmission and deformation carrier, can stably bear the external force indirectly transmitted by the output shaft 211 and generate corresponding deformation. The sensor 32 senses the force based on this deformation, avoiding interference from the movement of the output shaft 211 on the sensing signal, making the brushing force detection more stable and the data more accurate, thus more reliably realizing the function of "reminding the user when the force is too strong", thereby better protecting the user's dental health and improving brushing comfort.

[0048] The above describes the main working principle of the electric toothbrush and handle 100 disclosed herein. In order to more clearly explain the internal structure of the handle 100, the following will describe in detail four different assembly methods of the elastic sheet 31 and the drive component 2 in four embodiments, and how the output shaft 211 indirectly drives the elastic sheet 31 to deform under the action of external force in each assembly method.

[0049] Example 1 refer to Figure 4The elastic sheet 31 includes a first end 311 and a second end 312 disposed opposite to each other. Specifically, in this embodiment, the elastic sheet 31 is configured to extend along the first axis direction (i.e., the X-axis direction), the first end 311 is configured to be away from the output shaft 211, and the second end 312 is configured to be close to the output shaft 211. As mentioned above, the first axis is the central axis of the output shaft 211 of the drive motor 21. The elastic sheet 31 extends in a "horizontal strip" shape along the first axis direction, thereby achieving efficient space utilization.

[0050] Specifically, the diameter of the outer shell 1 of the handle 100 is typically only 20-30mm, and its cavity 10 has very limited space. The layout of the elastic piece 31 extending along the first axis (X-axis) avoids it occupying too much space in the radial direction, thereby allowing it to be compactly arranged with components such as the battery 5 and the control motherboard 4, avoiding layout conflicts between components in the cavity 10. At the same time, the outer shell 1 does not need to increase its diameter due to the design of the elastic piece 31, thus not affecting the grip feel of the outer shell 1.

[0051] The first end 311 is configured to be fixedly connected to the motor housing 22. Specifically, a hole can be made on the elastic sheet 31 near the first end 311, and a corresponding hole is also made on the motor housing 22 at the same position. A fixing pin 34 passes through the two holes, thereby connecting the first end 311 of the elastic sheet 31 to the motor housing 22 through the fixing pin 34. After connection, the first end 311 and the motor housing 22 form a rigid whole with virtually no relative displacement. The rigid fixed design of the first end 311 and the motor housing 22 prevents the elastic sheet 31 from loosening or shifting during the vibration of the drive motor 21 or the transmission of external forces, ensuring that the elastic sheet 31 is always in the preset detection position and improving the reference stability of force sensing.

[0052] The second end 312 is configured to mate with the drive motor 21, and the output shaft 211 is configured to drive the drive motor 21 to move relative to the motor housing 22 under the action of an external force, thereby deforming the elastic sheet 31. Specifically, the drive motor 21 is configured to apply a force to the second end 312 and / or the position on the elastic sheet 31 adjacent to the second end 312 under the action of an external force, thereby deforming the elastic sheet 31. When the user brushes their teeth, during the force-driven movement of the output shaft 211, the drive motor 21 will undergo a slight displacement due to the force, thereby pressing the second end 312 of the elastic sheet 31, causing the elastic sheet 31 to change from an initial straight state to a curved state with a certain curvature. This achieves optimized force transmission efficiency. Specifically, this disclosure limits the force application location to the second end 312 and the adjacent area, so that the elastic sheet 31 forms a clear force-bearing structure of "the first end 311 is used for fixing and the second end 312 is used for deformation". External force does not need to be distributed to the entire elastic sheet 31, but only needs to act on the second end 312 and the adjacent area to cause significant deformation. The sensor 32 can more accurately capture minute force changes, solving the pain point of insensitive pressure sensing in the prior art.

[0053] In one embodiment of this disclosure, the elastic sheet 31 is configured such that, during deformation, its connection point with the motor housing 22 serves as the deformation fulcrum. In this embodiment, the location of the fixing pin 34 is the deformation fulcrum. When an external force is applied to the second end 312 of the elastic sheet 31, the elastic sheet 31 undergoes lever-like bending around the deformation fulcrum. The deformation fulcrum remains fixed, while the second end 312 can warp. The deformation of the elastic sheet 31 gradually increases from the deformation fulcrum towards the second end 312. This lever-like deformation structure can convert the minute external force transmitted by the output shaft 211 into a significant deformation of the second end 312. The sensor 32 can identify the force without detecting extremely small deformations, avoiding the problem of difficulty in capturing minute forces and improving sensing sensitivity. Furthermore, the fixed deformation fulcrum ensures that each deformation of the elastic sheet 31 follows a preset trajectory, guaranteeing the consistency of the deformation trajectory and avoiding irregular deformations such as twisting and shifting that may occur when there is no fixed fulcrum, thus improving the accuracy of force detection.

[0054] Furthermore, the sensor 32 is configured to be fixed on the elastic sheet 31 near the deformation fulcrum. For example, the sensor 32 can be attached to the middle of the elastic sheet 31 near the deformation fulcrum. It should be noted that this position is in the linearly sensitive area of ​​the elastic sheet 31's deformation. In lever-type deformation, the closer the area is to the deformation fulcrum, the closer the relationship between deformation and external force is to the ideal linearity. However, the area farther from the deformation fulcrum has a larger degree of deformation and is prone to excessive bending, resulting in a larger linear deviation. This disclosure places the sensor 32 near the deformation fulcrum, thereby converting the pressure signal into a high-gradient, linearized local stress field through mechanical design. The deformation signal of the elastic sheet 31 captured by the sensor 32 can more accurately reflect the actual brushing force, avoiding the core pain point of inaccurate pressure sensing in the prior art, especially suitable for electric toothbrushes that need to distinguish subtle differences in force.

[0055] In one embodiment of this disclosure, such as Figure 4 As shown, the elastic sheet 31 is configured to be located on the first direction S1 side of the drive assembly 2, and the output shaft 211 is configured to move in the first direction S1 under the action of an external force to cause the elastic sheet 31 to deform. Specifically, a protrusion 231 is provided on the first direction S1 sidewall of the drive motor 21, and the protrusion 231 is configured to be pre-pressed onto the elastic sheet 31 at a position adjacent to the second end 312. The output shaft 211 is configured to drive the protrusion 231 to move in the first direction under the action of an external force to compress the elastic sheet 31 to deform. When the user brushes their teeth with greater force, the output shaft 211 will be subjected to a reaction force and will drive the drive motor 21 to move in the first direction S1 as a whole. At this time, the protrusion 231 moves downward synchronously with the drive motor 21, applying directional pressure to the elastic sheet 31, forcing the elastic sheet 31 to bend downward with the position connected to the motor housing 22 as the deformation fulcrum. The amount of deformation is proportional to the displacement of the drive motor 21.

[0056] This disclosure allows the elastic sheet 31 to be pre-installed in a state of contact with the protrusion 231, with no initial gap between them. Therefore, when the output shaft 211 is subjected to force, the protrusion 231 can quickly transmit pressure to the elastic sheet 31, avoiding response delay and enabling real-time capture of sudden changes in brushing force. Furthermore, the pre-pressure design of the protrusion 231 allows for slight positional deviations during assembly of the elastic sheet 31. The pre-pressure automatically adjusts the contact state between the protrusion 231 and the elastic sheet 31, thus eliminating the need for high-precision positioning and assembly of the elastic sheet 31, reducing assembly difficulty during production.

[0057] In one embodiment of this disclosure, the drive assembly 2 includes a flexible sleeve 23 configured to at least partially enclose the drive motor 21, with a protrusion 231 disposed on the flexible sleeve 23. The flexible sleeve 23 can be made of a soft, elastic material such as silicone or rubber. Enclosing the drive motor 21 with the flexible sleeve 23 helps to buffer the vibration of the drive motor 21 during operation. The protrusion 231 can be integrally formed on the end face of the flexible sleeve 23 facing the elastic sheet 31 (i.e., the end face in the first direction S1), and the protrusion 231 can be made of the same material as the flexible sleeve 23. When the drive motor 21 operates, it generates high-frequency micro-vibrations. The flexible sleeve 23 can absorb some of the vibration energy, thereby preventing the vibration from being transmitted to the elastic sheet 31 and causing false triggering deformation, which could lead to misjudgment by the sensor 32, thus improving the detection accuracy. Furthermore, since the flexible sleeve 23 and the protrusion 231 are integrally formed, during assembly, the flexible sleeve 23 only needs to be directly placed on the drive motor 21, without the need to install the protrusion 231 separately, reducing the assembly difficulty.

[0058] Example 2 The main difference between this embodiment and Embodiment 1 is that the position where the drive motor 21 applies force to the elastic sheet 31 under external force is different. In Embodiment 1, force transmission is achieved by pressing the position of the protrusion 231 on the elastic sheet 31 near the second end 312; while in this embodiment, the drive motor 21 can accurately apply force to the second end 312 of the elastic sheet 31.

[0059] In one embodiment of this disclosure, reference is made to Figure 5 The elastic sheet 31 includes a connecting portion 313 disposed at its second end 312. The connecting portion 313 is configured to extend to connect with the drive motor 21, and the drive motor 21 is configured to drive the elastic sheet 31 to deform via the connecting portion 313. In this embodiment, the first end 311 is also configured to be fixedly connected to the motor housing 22, and its second end 312 is provided with a connecting portion 313 that is directly connected to the drive motor 21, thereby enabling the drive motor 21 to accurately apply force to the second end 312 of the elastic sheet 31. The connecting portion 313 can be integrally formed with the elastic sheet 31, and both can be made of the same material, thereby allowing the connecting portion 313 to directly drive the second end 312 of the elastic sheet 31 to move without the need for additional connecting structures.

[0060] Specifically, the first end 311 of the elastic sheet 31 can be fixed to the motor housing 22 by screws, welding, or other means, thus forming a rigid connection. It can be assumed that there is no relative displacement between the first end 311 of the elastic sheet 31 and the motor housing 22. The second end 312 of the elastic sheet 31 is rigidly fixed to the drive motor 21 through the connecting part 313, thereby making the drive motor 21 and the second end 312 of the elastic sheet 31 synchronous motion units. During brushing, the reaction force of the brush head 200 is transmitted to the drive motor 21 along the output shaft 211. The drive motor 21 can undergo a slight displacement relative to the motor housing 22, thereby causing the second end 312 of the elastic sheet 31 to displace relative to the first end 311, resulting in deformation of the elastic sheet 31. The degree of deformation of the elastic sheet 31 is directly proportional to the displacement of the drive motor 21 relative to the motor housing 22.

[0061] This disclosure utilizes a linear transmission chain: "output shaft 211 is subjected to force → drive motor 21 moves relative to motor housing 22 → connection part 313 transmits motion → elastic sheet 31 deforms." This avoids force dispersion or delay during transmission, improving detection accuracy. The structure provided in this embodiment effectively simplifies the force transmission path. The double rigid fixing structure of the drive motor 21 and motor housing 22 at both ends of the elastic sheet 31 shortens the force transmission path. Furthermore, when the output shaft 211 is subjected to force, the drive motor 21 can quickly transmit pressure to the elastic sheet 31, avoiding response delay issues, improving response speed, and enabling real-time capture of sudden changes in brushing force.

[0062] In one embodiment of this disclosure, such as Figure 5 As shown, the connecting portion 313 is configured to be fixedly connected to the side of the drive motor 21 where the output shaft 211 is located. This fixes the connecting portion 313 at the position closest to the point of application of the external force (i.e., the output shaft 211), shortening the force transmission path, reducing force loss during transmission, and making the correspondence between the deformation of the elastic sheet 31 and the brushing force more precise. During the movement of the drive motor 21, to avoid interference between the output shaft 211 and the connecting portion 313, this disclosure provides a clearance area on the connecting portion 313, configured to allow for clearance of the extension path of the output shaft 211.

[0063] The connecting part 313 can adopt a U-shaped structure design. The opening in the middle of the U-shaped structure is the clearance area, and the two ends of the U-shaped structure are used to fix and connect to the end face of the drive motor 21. The U-shaped clearance area provides an independent rotation space for the output shaft 211, and the output shaft 211 will not rub or collide with the connecting part 313 during normal operation. The U-shaped clearance area achieves the coexistence of the output shaft 211 and the connecting part 313 through a partial hollowing design, thus eliminating the need to increase the size of the connecting part 313 to accommodate the output shaft 211, and adapting to the compact space of the cavity 10 of the handle 100.

[0064] In one embodiment of this disclosure, the connecting portion 313 is configured to extend along a second direction S2 to connect with the drive motor 21. The drive motor 21 is configured to drive the connecting portion 313 to move in a first direction S1, thereby causing the elastic sheet 31 to deform. The elastic sheet 31 is arranged substantially parallel to the output shaft 211, and the extending direction of the connecting portion 313 is substantially perpendicular to the elastic sheet 31. The second end 312 is fixed to the end face of the drive motor 21. When the drive motor 21 moves in the first direction S1, the force can be directly transmitted to the second end 312 of the elastic sheet 31 along a vertical path, thereby improving the sensing sensitivity. In addition, the vertical extension structure of the connecting portion 313 does not require the longitudinal space of the handle 100, improving the space utilization of the cavity 10.

[0065] Example 3 refer to Figure 6 and Figure 7 An elastic arm 24 is provided on the motor housing 22. As mentioned earlier, the motor housing 22 includes a cover plate 221 mounted on a mounting bracket, and the elastic arm 24 can be disposed on the cover plate 221. The elastic arm 24 is elongated and has deformable elastic properties. The elastic arm 24 includes a fixed end 241 and a free end 242 disposed opposite to each other. The free end 242 is configured to be pre-pressed between the elastic sheet 31 and the outer housing 1. Under the driving action of the output shaft 211, the free end 242 is configured to apply a force to the elastic sheet 31, so that the elastic sheet 31 deforms.

[0066] Specifically, the fixed end 241 is rigidly connected to the motor housing 22, for example, by injection molding, screw fixing, welding, etc., to ensure that the fixed end 241 will not shift relative to the motor housing 22. The free end 242 extends naturally between the elastic plate 31 and the outer shell 1, and is in a pre-compression state after assembly. The free end 242 can simultaneously contact and cooperate with the surface of the elastic plate 31 and the inner wall of the outer shell 1, and form a pre-tightening force through the elastic characteristics of the elastic arm 24 itself, so that the three are kept in close contact. When the output shaft 211 is subjected to external force, the output shaft 211 will drive the drive component 2 to change position. At this time, the free end 242 of the elastic arm 24 is constrained by the inner wall of the outer shell 1 and cannot move synchronously with the drive component 2, thus applying a force to the elastic plate 31, forcing the elastic plate 31 to bend and deform.

[0067] This disclosure eliminates the gap between the elastic plate 31 and the transmission component by setting an elastic arm 24, thereby avoiding the response lag problem where "external force must overcome the gap before it can push the elastic plate 31". This ensures that changes in brushing force are transmitted to the elastic plate 31 in real time, improving the timeliness of the sensor 32's response. At the same time, the elastic arm 24 itself is elastic and can buffer external impacts through deformation, thereby avoiding excessive local stress and permanent deformation of the elastic plate 31 caused by rigid transmission, and extending the service life of the elastic plate 31.

[0068] In one embodiment of this disclosure, the drive motor 21 is configured to be fixedly mounted on the motor housing 22, and the output shaft 211 is configured to drive the entire drive assembly 2 to move relative to the outer shell 1 under the action of an external force. During the movement of the drive assembly 2, the free end 242 is configured to maintain contact with the elastic plate 31 and the inner wall of the outer shell 1 under the elastic force of the elastic arm 24. Specifically, the drive motor 21 can be rigidly connected to the motor housing 22 through a fixed structure (such as screw locking or slot positioning), forming a drive assembly 2 that cannot move relative to each other; the output shaft 211 extends out of the motor housing 22, and when the output shaft 211 is subjected to an external force, it will drive the entire drive assembly 2 (drive motor 21 + motor housing 22) to move relative to the outer shell 1. Because the free end 242 of the elastic arm 24 is always in contact with the inner wall of the outer shell 1, its movement trajectory is restricted by the inner wall of the outer shell 1 during the movement of the drive assembly 2, while maintaining contact with the elastic plate 31 by its own elasticity, and will not disengage. In this embodiment, the design of the drive assembly 2 as a whole avoids the problem of misalignment between the drive motor 21 and the motor housing 22 due to the individual movement of the drive motor 21. This simplifies the force transmission path to "drive assembly 2 as a whole → elastic arm 24 → elastic sheet 31," reducing the dispersion and loss of force during transmission. This ensures that even a small brushing force can effectively drive the elastic sheet 31 to deform, improving the sensitivity of force sensing. Furthermore, the continuous contact characteristic of the free end 242 of the elastic arm 24 eliminates signal fluctuations in the sensor 32 caused by "contact / separation" state switching, ensuring the stability of the detection signal and reducing the risk of false or missed detections due to contact interruption. Simultaneously, the relative movement space between the drive assembly 2 and the housing 1 provides sufficient margin for the deformation of the elastic arm 24 and the elastic sheet 31, preventing interference between components due to restricted movement.

[0069] In one embodiment of this disclosure, when the output shaft 211 is not subjected to external force, the free end 242 is configured to apply a preset force to the elastic sheet 31. During the movement of the drive assembly 2, the force applied by the free end 242 to the elastic sheet 31 is configured to change, causing the elastic sheet 31 to deform. Specifically, when the output shaft 211 is not subjected to external force, the free end 242 of the elastic arm 24, due to its pre-compression state, applies a preset force to the elastic sheet 31. This force can be determined by the initial deformation of the elastic arm 24, placing the elastic sheet 31 in a slightly deformed pre-compression state, thereby providing a stable initial detection reference for the sensor 32. In this embodiment, the design of the preset force establishes a stable initial reference for the sensor 32, avoiding the problem of no deformation of the elastic sheet 31 and signal drift of the sensor 32 in the zero-force state, thus improving the detection accuracy in the low-force range. In addition, the elastic sheet 31 in the pre-compression state is more sensitive to external force and can quickly respond to small changes in force, further improving the timeliness of detection. When the output shaft 211 is driven by an external force to move the drive assembly 2, the displacement of the drive assembly 2 changes the degree of deformation of the elastic arm 24. When the drive assembly 2 moves towards the side where the elastic arm 24 is located, the elastic arm 24 is further compressed, and the force exerted by the free end 242 on the elastic sheet 31 increases accordingly; when the drive assembly 2 moves towards the side where the elastic arm 24 is not located, the compression of the elastic arm 24 decreases, and the force exerted by the free end 242 on the elastic sheet 31 decreases accordingly. The change in the force applied by the free end 242 directly causes a corresponding change in the deformation of the elastic sheet 31, and the sensor 32 detects the brushing force by capturing the difference in deformation.

[0070] In one embodiment of this disclosure, the elastic sheet 31 is configured such that, during deformation, its contact point with the free end 242 serves as the deformation fulcrum. The remaining area of ​​the elastic sheet 31 (i.e., the portion relatively far from the contact point) can deform around this deformation fulcrum, with the deformation direction consistent with the force direction of the free end 242 of the elastic arm 24. Furthermore, the deformation trajectory is constrained by the deformation fulcrum, always maintaining a preset bending path. This avoids irregular deformations such as twisting and shifting that may occur with the elastic sheet 31 in structures without a fixed fulcrum, ensuring consistency in the deformation of the elastic sheet 31 caused by each change in force, and improving the repeatability and accuracy of the sensor 32's detection. Moreover, the position of the deformation fulcrum is determined by the contact point of the free end 242 of the elastic arm 24, thus eliminating the need for an additional independent deformation fulcrum structure, simplifying the assembly and positioning of the elastic sheet 31, and reducing structural complexity.

[0071] In one embodiment of this disclosure, such as Figure 6As shown, the elastic sheet 31 includes a first end 311 and a second end 312 disposed opposite to each other. The first end 311 is configured to be fixedly connected to the motor housing 22 and / or the drive motor 21, and the second end 312 is configured to extend between the motor housing 22 and the elastic arm 24. Specifically, the first end 311 of the elastic sheet 31 can be optionally fixedly connected to the motor housing 22, or optionally fixedly connected to the drive motor 21, or can be connected to both simultaneously. The first end 311 is rigidly connected to the drive assembly 2, thereby ensuring that the first end 311 can move synchronously with the drive assembly 2. The second end 312 extends into the space between the motor housing 22 and the elastic arm 24, so that the free end 242 of the elastic arm 24 can apply a preset force to the elastic sheet 31 near the position of the second end 312.

[0072] The output shaft 211 is configured to drive the first end 311 to move relative to the housing 1 under the action of an external force, so as to deform the elastic sheet 31. Specifically, when the output shaft 211 is subjected to an external force, it will drive the drive assembly 2 to move as a whole, and then drive the first end 311 of the elastic sheet 31, which is fixed to the drive assembly 2, to move synchronously. Since the second end 312 is clamped between the motor housing 22 and the elastic arm 24, it cannot move freely with the first end 311 due to the spatial constraints of the two. This creates a differential speed state in which the first end 311 moves and the second end 312 is restricted, causing the elastic sheet 31 to bend and deform.

[0073] This embodiment employs a structural design where the second end 312 extends between the motor housing 22 and the elastic arm 24. This utilizes the spatial constraints between the two ends to limit the movement of the second end 312, eliminating the need for additional limiting components. This simplifies the structure while ensuring that the elastic plate 31 can effectively deform due to the difference in movement between its two ends. Furthermore, this layout allows the elastic plate 31 to be compactly installed with the drive assembly 2, occupying virtually no additional space in the cavity 10, and fitting the compact internal structure of the handle 100.

[0074] In one specific embodiment of this disclosure, the elastic sheet 31 is configured to extend along a first axial direction (i.e., the X-axis direction). The extension direction of the elastic sheet 31 remains substantially parallel to the output shaft 211, thereby maximizing the use of the axial space of the drive assembly 2 and avoiding excessive radial space occupation, thus adapting to the elongated cavity 10 structure design of the handle 100. Simultaneously, the parallel arrangement to the output shaft 211 ensures that the deformation direction of the elastic sheet 31 is consistent with the force direction of the output shaft 211, eliminating the need to change the direction of force transmission, reducing force loss, and ensuring that even small forces can induce significant deformation.

[0075] In one embodiment of this disclosure, the sensor 32 is configured to be fixed to the elastic sheet 31 at a position adjacent to the first end 311. While this position does not exhibit the same deformation as the center of the elastic sheet 31, it falls within the linearly sensitive region of the elastic sheet 31's deformation. By positioning the sensor 32 near the first end 311, it avoids areas of excessive deformation in the elastic sheet 31, preventing signal saturation due to excessive deformation and ensuring that the sensor 32 outputs a stable linear signal across the entire force detection range, thereby improving detection accuracy. The sensor 32 can be fixed to the elastic sheet 31 by means of adhesive or other methods, ensuring real-time capture of minute deformations in this area.

[0076] Example 4 Similar to Embodiment 3, this embodiment also includes an elastic arm 24 structure, and the elastic arm 24 structure can also be disposed on the cover plate 221. The main difference between this embodiment and Embodiment 1 is that there are two elastic arms 24, and correspondingly, the specific arrangement of the elastic sheet 31 has also changed.

[0077] refer to Figures 9 to 13 Two elastic arms 24 are spaced apart on the motor housing 22. As mentioned earlier, the fixed end 241 of the elastic arm 24 is fixedly connected to the motor housing 22, for example, it can be integrally formed with the cover plate 221. The free end 242 of the elastic arm 24 is pre-pressed against the inner wall of the outer casing 1. The structures of the two elastic arms 24 can be completely identical and can be symmetrically arranged on opposite sides of the motor housing 22. The free ends 242 of the two elastic arms 24 are respectively connected to the opposite ends of the elastic sheet 31. The free ends 242 can form a pre-pressed contact with the opposite ends of the elastic sheet 31, and at the same time, the free ends 242 are also tightly fitted against the inner wall of the outer casing 1.

[0078] Driven by the output shaft 211, the two free ends 242 are configured to apply forces to the opposite ends of the elastic sheet 31, causing the elastic sheet 31 to deform. Specifically, when the output shaft 211 is driven by an external force to move the entire drive assembly 2, the free ends 242 of the two elastic arms 24 are constrained by the inner wall of the outer shell 1 and cannot move synchronously with the drive assembly 2. Consequently, they apply forces of the same direction and similar magnitude to the two ends of the elastic sheet 31, ultimately forcing the middle area of ​​the elastic sheet 31 to bend and deform, with the deformation trajectory being a basically symmetrical arc.

[0079] This embodiment avoids the unilateral deflection problem that may occur when a single elastic arm 24 applies pressure to one end of the elastic sheet 31. Under the action of the free ends 242 of the two elastic arms 24, both ends of the elastic sheet 31 are subjected to balanced forces, and the deformation of the elastic sheet 31 unfolds symmetrically around the central axis, avoiding signal deviation of the sensor 32 caused by irregular deformation, and significantly improving the repeatability and accuracy of detection. At the same time, symmetrical force application makes the force distribution of the elastic sheet 31 more uniform, avoiding local stress concentration (such as excessive force on one end of the elastic sheet 31 when a single elastic arm 24 applies force), effectively preventing permanent deformation of the elastic sheet 31 due to long-term unilateral force, and extending the service life of the elastic sheet 31.

[0080] In one embodiment of this disclosure, reference is made to Figure 9 and Figure 12 The sensor 32 is configured to be fixed at the middle position of the elastic sheet 31. Specifically, the sensor 32 is located at the midpoint of the extended length of the elastic sheet 31, and also at the midpoint of the line connecting the free ends 242 of the two elastic arms 24. As the two elastic arms 24 apply force to both ends of the elastic sheet 31, the deformation of the elastic sheet 31 gradually increases from both ends to the middle. The middle position becomes the maximum deformation zone of the elastic sheet 31, and the deformation trajectory in this region is the most stable. The sensor 32 can directly capture the most significant and regular deformation signal, effectively improving the detection sensitivity.

[0081] In one embodiment of this disclosure, reference is made to Figure 12 and Figure 13 A soft rubber pad 6 is provided between the sensor 32 and the drive motor 21. Specifically, the soft rubber pad 6 can be positioned below the elastic sheet 31 corresponding to the position of the sensor 32, and the soft rubber pad 6 can at least cover the lower surface of the sensor 32. The soft rubber pad 6 can be made of a soft material with certain elasticity and insulation, and its shape is basically consistent with the shape of the lower surface of the sensor 32. For example, when the sensor 32 is rectangular, the soft rubber pad 6 can also be set as rectangular. The soft rubber pad 6 is fixed between the sensor 32 and the drive motor 21 by adhesive or slight pressure. The three are tightly fitted but without rigid pressure, ensuring that the soft rubber pad can be freely compressed or rebounded. The soft rubber pad 6 isolates the vibration of the drive motor 21. When the drive motor 21 operates, it generates high-frequency, minute vibrations. If the sensor 32 is directly close to the drive motor 21, these vibrations can easily be transmitted to the sensor 32, causing it to capture incorrect "deformation signals" and resulting in misjudgments. The elastic material of the soft rubber pad 6 absorbs some of the vibration energy, significantly reducing the intensity of the vibration transmitted to the sensor 32. This allows the sensor 32 to capture only the true signal caused by the deformation of the elastic pad 31, thereby improving detection accuracy. Furthermore, the elasticity of the soft rubber pad 6 cushions rigid collisions between the sensor 32 and the drive motor 21, preventing physical damage to the sensor 32 and further enhancing its reliability.

[0082] In one embodiment of this disclosure, the elastic sheet 31 is configured to extend along a second axis perpendicular to the first axis, with reference to... Figure 8 The Y-axis, perpendicular to the X-axis, is the second axis, which is parallel to the radial direction of the handle 100. In this embodiment, the elastic sheet 31 is arranged laterally and is perpendicular to the longitudinal extension direction of the output shaft 211. The opposite ends of the elastic sheet 31 are pre-pressed into contact with the free ends 242 of the two elastic arms 24, and the middle region of the elastic sheet 31 forms a suspended structure that does not contact other components, thus reserving space for deformation. The extension length of the elastic sheet 31 matches the spacing between the two elastic arms 24, ensuring that its two ends can completely cover the contact range of the free ends 242 of the elastic arms 24. The elastic plate 31 extending along the second axis is aligned with the overall movement direction of the drive assembly 2. The drive assembly 2 can move radially along the handle 100. The radial force applied by the two elastic arms 24 to both ends of the elastic plate 31 can be directly converted into radial deformation of the elastic plate 31, thereby reducing force loss during direction conversion and ensuring that even a small brushing force can induce significant deformation, thus improving force transmission efficiency. In addition, the elastic plate 31 is arranged perpendicularly to the output shaft 211, completely separating the deformation trajectory of the elastic plate 31 from the rotation trajectory of the output shaft 211. This avoids interference between the output shaft 211 and the elastic plate 31 when it rotates, thus protecting both the elastic plate 31 and the output shaft 211.

[0083] In one embodiment of this disclosure, reference is made to Figure 10 and Figure 11The two elastic arms 24 are interconnected by a connecting arm 25, which is located between the elastic sheet 31 and the outer casing 1. The connecting arm 25 strengthens and integrates the two elastic arms 24, forming a linked whole. This significantly reduces the relative movement between the two elastic arms 24, preventing independent offset and asynchronous force application when force is applied to one side. It ensures that the free ends 242 of the two elastic arms 24 always apply a balanced force synchronously to both ends of the elastic sheet 31, resulting in uniform force distribution and minimal fluctuation on the elastic sheet 31, leading to symmetrical and more stable deformation. The stable force distribution on the elastic sheet 31 directly ensures that the deformation signal captured by the sensor 32 is purer, free from additional interference, significantly reducing detection errors and ensuring more accurate and reliable brushing force detection.

[0084] In one embodiment of this disclosure, reference is made to Figure 10 and Figure 11 The connecting arm 25 is provided with a limiting part 251, and the inner wall of the outer shell 1 is provided with a mating part (not shown in the figure) for cooperating with the limiting part 251. The limiting part 251 is configured to at least limit the degree of freedom of movement of the motor housing 22 relative to the outer shell 1 in the circumferential direction. Specifically, the limiting part 251 may be a protrusion, rib, or block structure that extends along the length direction of the connecting arm 25; correspondingly, the mating part on the inner wall of the outer shell 1 that is adapted to the limiting part 251 may be a recessed structure such as a groove or a slot, and the shape and size of the mating part are completely matched with the limiting part 251 to ensure that the limiting part 251 can be embedded in the mating part without obvious loosening.

[0085] When the drive assembly 2 moves relative to the housing 1, the limiting part 251 can only slide in the radial direction of the drive assembly 2 (i.e., the direction of movement of the drive assembly 2) within the mating part, and cannot rotate circumferentially. This indirectly restricts the circumferential freedom of the motor housing 22 through the connecting arm 25, preventing the motor housing 22 from rotating around the first axis. The circumferential constraint design of the limiting part 251 and the mating part solves the problem of circumferential misalignment that may occur during the movement of the drive assembly 2, thereby preventing the two elastic arms 24 from deviating from the preset force application position, thus protecting the sensing assembly 3.

[0086] Furthermore, the circumferential constraint also enhances the overall structural stability of the drive assembly 2. Compared with the solution in Embodiment 3, the motor housing 22 in this embodiment no longer relies solely on the contact positioning between the elastic arm 24 and the outer shell 1. Instead, it forms an additional rigid constraint through the limiting part 251 and the mating part, reducing the vibration offset of the drive assembly 2 during operation, preventing changes in the pre-compression state of the elastic arm 24 due to vibration, and ensuring the stability of the initial reference signal of the sensor 32. In addition, the "embedded" fit between the limiting part 251 and the mating part does not require additional fasteners. Constraint can be achieved solely through structural adaptation, simplifying the assembly process and not increasing the space occupied by the cavity 10 of the handle 100.

[0087] In one embodiment of this disclosure, the connecting arm 25 is configured to at least partially cover the elastic sheet 31 in the radial direction of the drive assembly 2. By covering at least part of the elastic sheet 31, the connecting arm 25 directly separates the elastic sheet 31 from the inner wall of the housing 1, preventing direct contact between the two and providing targeted protection for the sensing assembly 3, thus extending the service life of the sensing assembly 3. Furthermore, when covering the elastic sheet 31, the connecting arm 25 can leave a certain gap with the elastic sheet 31, thereby forming a suspended covering structure, ensuring that the deformation function of the elastic sheet 31 is not affected; alternatively, the connecting arm 25 can also lightly touch the surface of the elastic sheet 31 through its own elasticity, thereby forming a slight contact covering. The connecting arm 25 does not apply additional pressure to the elastic sheet 31, thus ensuring that the elastic sheet 31 can be freely bent and deformed. In this embodiment, the connecting arm 25 adopts a non-rigid contact design. While providing protection, the connecting arm 25 does not restrict the normal bending deformation of the elastic sheet 31, ensuring that force transmission and deformation detection are not affected, thereby extending the service life of the elastic sheet 31 while ensuring detection reliability.

[0088] In one embodiment of this disclosure, reference is made to Figure 10 and Figure 11 The connecting arm 25 is provided with a mating groove 252, which is configured to accommodate the sensor 32. The mating groove 252 provides space for the sensor 32 to be accommodated and deformed, preventing the sensor 32 from contacting other structures. It is understood that the sensor 32 needs sufficient room to move when it deforms with the elastic sheet 31. The size of the mating groove 252 is larger than the volume of the sensor 32, so that the mating groove 252 can fully accommodate the sensor 32 and reserve a certain deformation margin, preventing the sensor 32 from being squeezed and damaged due to insufficient space, and preventing it from colliding and interfering with the elastic arm 24 or the connecting arm 25 during its deformation movement with the elastic sheet 31, ensuring that the sensor 32 can stably capture the deformation signal of the elastic sheet 31.

[0089] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of this disclosure is defined by the appended claims.

Claims

1. An electric toothbrush, comprising a handle and a brush head disposed on the handle, characterized in that, The handle includes: The outer casing has a cavity; a drive motor and a motor housing are disposed in the cavity; the drive motor has an output shaft extending along a first axis, and the output shaft is configured to connect to the brush head; the drive motor is mounted in the cavity through the motor housing. A sensing assembly, comprising a sensor and an elastic sheet abutting against the sensor; the elastic sheet is configured to extend along a first axis, and the opposite ends of the elastic sheet are respectively referred to as a first end and a second end; the first end is configured to be fixedly connected to the motor housing, and the second end is configured to be installed in conjunction with the drive motor; The output shaft is configured to drive the drive motor to move relative to the motor housing under the action of an external force, thereby causing the elastic sheet to deform; the sensor is configured to sense the force based on the deformation of the elastic sheet.

2. The electric toothbrush according to claim 1, characterized in that, The elastic sheet is configured such that, during deformation, its connection point with the motor housing serves as the deformation fulcrum.

3. The electric toothbrush according to claim 2, characterized in that, The sensor is configured to be fixed on the elastic sheet at a position adjacent to the deformation fulcrum.

4. The electric toothbrush according to claim 1, characterized in that, The elastic sheet is configured to be located on the first direction side of the drive motor; the output shaft is configured to move in the first direction under the action of an external force, so as to cause the elastic sheet to deform.

5. The electric toothbrush according to claim 4, characterized in that, The first end is configured to be away from the output shaft, and the second end is configured to be close to the output shaft; the drive motor is configured to apply a force to a position on the elastic sheet adjacent to the second end under the action of an external force, so as to deform the elastic sheet.

6. The electric toothbrush according to claim 5, characterized in that, A protrusion is provided on the first direction sidewall of the drive motor. The protrusion is configured to be pre-pressed onto the elastic sheet at a position adjacent to the second end. The output shaft is configured to drive the protrusion to move in the first direction under the action of an external force, so as to compress the elastic sheet to deform.

7. The electric toothbrush according to claim 6, characterized in that, A flexible sleeve is provided outside the drive motor, the flexible sleeve being configured to at least partially enclose the drive motor; the protrusion is provided on the flexible sleeve.

8. The electric toothbrush according to claim 4, characterized in that, The first end is configured to be away from the output shaft, and the second end is configured to be close to the output shaft; the drive motor is configured to apply a force to the second end under the action of an external force, so as to deform the elastic sheet.

9. The electric toothbrush according to claim 8, characterized in that, The elastic sheet includes a connecting portion disposed at the second end, the connecting portion being configured to extend to connect with the drive motor; the drive motor is configured to drive the elastic sheet to deform through the connecting portion.

10. The electric toothbrush according to claim 9, characterized in that, The connecting portion is configured to extend along a second direction to connect with the drive motor, the second direction being opposite to the first direction; the drive motor is configured to drive the connecting portion to move in the first direction, thereby causing the elastic sheet to deform.

11. The electric toothbrush according to claim 9, characterized in that, The connecting part is configured to be fixedly connected to the side of the drive motor where the output shaft is located; the connecting part is provided with a clearance area, which is configured to avoid the extension path of the output shaft.

12. The electric toothbrush according to claim 1, characterized in that, The drive motor is a servo motor.

13. The electric toothbrush according to claim 1, characterized in that, It also includes a control motherboard; the control motherboard is configured to be located in the cavity and to be communicatively connected to the sensor; the control motherboard is configured to determine the pressure value of the output shaft based on the electrical signal output by the sensor; and when the pressure value is greater than a threshold, the control motherboard is configured to issue a warning signal.

14. The electric toothbrush according to claim 1, characterized in that, The brush head is configured to move the output axis away from the direction of the brush head under the action of an external force, so as to cause the elastic sheet to deform.

15. A handle, characterized in that, include: The housing has a cavity; a drive motor and a motor housing are disposed in the cavity; the drive motor has an output shaft extending along a first axis; the drive motor is mounted in the cavity through the motor housing. A sensing assembly, comprising a sensor and an elastic sheet abutting against the sensor; the elastic sheet is configured to extend along a first axis, and the opposite ends of the elastic sheet are respectively referred to as a first end and a second end; the first end is configured to be fixedly connected to the motor housing, and the second end is configured to be installed in conjunction with the drive motor; The output shaft is configured to drive the drive motor to move relative to the motor housing under the action of an external force, thereby causing the elastic sheet to deform; the sensor is configured to sense the force based on the deformation of the elastic sheet.

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