Personal care appliance

Abstract

Disclosed in the present invention is a personal care appliance. The personal care appliance comprises a handle housing and a rotary assembly. The rotary assembly comprises a stress element, when the stress element is subjected to an external force, the rotary assembly being capable of rotating relative to the handle housing; and a force measuring device, the force measuring device being configured to measure a force on the stress element. The force measuring device comprises an inductance device and a magnet; the magnet is configured to be opposite to a magnetic core of the inductance device so as to generate magnetic flux passing through the magnetic core of the inductance device; the position of the magnet relative to the inductance device changes as the rotary assembly rotates; and an output signal of the inductance device indicates the angle of rotation of the rotary assembly. The present invention uses the inductance device, which, under the action of a permanent magnet or an electromagnet, may enable the magnetic core to enter a magnetic saturation state, so that the acceleration of the inductance quantity of the inductance device decreases, resulting in a larger change amplitude of values measured by the force measuring device under the same external force, thereby more accurately and clearly indicating changes of displacement and reflecting the magnitudes of external forces.

Description

Personal care products Technical Field

[0001] The present invention relates to the technical field of personal oral care devices, and in particular to a personal care appliance with a force detection device. Background Art

[0002] In the current electric toothbrush market, reminding users to brush with appropriate pressure to protect gums is becoming a growing demand. Various solutions exist on the market for measuring the external force applied to electric toothbrush heads. However, due to the very limited deflection range of electric toothbrush heads, existing electric toothbrushes have limited force detection accuracy, resulting in large force detection errors and only a single force threshold.

[0003] Especially for some electric toothbrushes that use resonant components, when external force is applied to the brush head, the deflection amplitude of the rotating component in the inner core component of the electric toothbrush is smaller than that of the electric toothbrush using a DC motor. Therefore, for this type of electric toothbrush, it is more urgent to increase the detection accuracy of the external force and provide the user with accurate operating force indication.

[0004] Summary of the Invention

[0005] To overcome the deficiencies of the prior art, the present invention provides a personal care appliance, comprising: a handle housing; a rotating assembly, wherein the rotating assembly includes a force-bearing element extending outward relative to the handle housing, and when the force-bearing element is acted upon by an external force, the rotating assembly can rotate relative to the handle housing; and a force detection device, the force detection device being configured to detect the force on the force-bearing element; wherein the force detection device includes an inductor and a magnet, wherein the inductor includes a fixed magnetic core and a conductor surrounding the fixed magnetic core, and the magnet is arranged relative to the magnetic core in the inductor to generate a magnetic flux passing through the magnetic core of the inductor; the position of the magnet relative to the inductor shifts as the rotating assembly rotates, and the inductor outputs a signal indicating the angle of rotation of the rotating assembly, thereby further identifying the magnitude of the external force acting on the force-bearing element.

[0006] According to one aspect of the present invention, when the magnet is farthest from the inductor, the fixed magnetic core of the inductor is in an unsaturated state. When the magnet rotates with the rotating component and approaches the inductor, the magnetic flux generated by the magnet passing through the magnetic core causes the fixed magnetic core of the inductor to enter a magnetic saturation state.

[0007] According to another aspect of the present invention, when the magnet is located farthest from the fixed magnetic core of the inductor, the fixed magnetic core of the inductor has entered a magnetic saturation state. As the magnet approaches the fixed magnetic core of the inductor as the rotating component rotates, the change in magnetic flux generated by the magnet passing through the magnetic core aggravates the magnetic saturation state of the fixed magnetic core of the inductor; as the magnet moves away from the fixed magnetic core of the inductor as the rotating component rotates, the change in magnetic flux generated by the magnet passing through the magnetic core slows down the magnetic saturation state of the fixed magnetic core of the inductor.

[0008] According to another aspect of the present invention, when the magnet is located farthest from the fixed core of the inductor, the fixed core of the inductor is approximately at a moderate saturation critical point, and when the magnet is located closest to the fixed core of the inductor, the magnet causes the fixed core of the inductor to be approximately at a deep saturation critical point; when the magnet approaches the fixed core of the inductor as the rotating assembly rotates, the change in magnetic flux generated by the magnet passing through the core causes the magnetic saturation state of the fixed core of the inductor to intensify; when the magnet rotates away from the fixed core of the inductor as the rotating assembly rotates, the change in magnetic flux generated by the magnet passing through the core causes the magnetic saturation state of the fixed core of the inductor to slow down. The present invention uses an inductor that enters a magnetic core saturation state under the action of a permanent magnet or an electromagnet, causing the inductance of the inductor to decrease rapidly, and the change in the measured value obtained by the same displacement force detection device is larger, thereby being able to more accurately and clearly indicate the displacement change and reflect the magnitude of the external force.

[0009] According to another aspect of the present invention, the inductive device is fixed on a control circuit board arranged stationary relative to the handle housing, and the magnet is arranged on the rotating assembly; the personal care appliance further comprises an elastic element for resetting the rotating assembly relative to the handle housing.

[0010] According to another aspect of the present invention, the rotating assembly also includes a DC motor, the force-bearing element is a drive shaft or brush head driven by the DC motor, the magnet is arranged on a support member installed at one end of the motor away from the drive shaft, and the elastic element is arranged on the support member.

[0011] According to another aspect of the present invention, the magnet includes a first magnet and a second magnet, and the inductor includes a first inductor and a second inductor. When the first magnet rotates with the rotating component and is closest to the first inductor, the magnetic flux generated by the first magnet passing through the magnetic core causes the magnetic core of the inductor to enter a magnetic saturation state; when the second magnet rotates with the rotating component and is closest to the second inductor, the magnetic flux generated by the second magnet passing through the magnetic core causes the magnetic core of the second inductor to enter a magnetic saturation state.

[0012] According to another aspect of the present invention, a personal care appliance includes a resonant assembly and a coil assembly fixedly mounted relative to a handle housing, the resonant assembly including a permanent magnet, a permanent magnet bracket for mounting the permanent magnet, and a drive shaft serving as a force-bearing element or connecting the force-bearing element, and the personal care appliance also includes a first bearing and a second bearing, the first bearing being closer to the drive shaft than the second bearing, the first bearing and the second bearing being arranged to allow the resonant assembly to reciprocate relative to the handle housing around the axis of the drive shaft when the magnetic lines of force of the permanent magnet cut the current carried by the coil assembly; the rotating assembly includes a first bearing and a second bearing, and when an external force to be measured is applied to the force-bearing element, the rotating assembly can rotate around a pivot axis, the pivot axis passing through one of the first bearing and the second bearing and being perpendicular to the rotation axis of the drive shaft, the other of the first bearing and the second bearing being movably arranged relative to the handle housing. Generally, the direction of the external force to be measured is consistent with the longitudinal direction of the cleaning element on the force-bearing element. For a toothbrush head, the direction of the external force to be measured is consistent with the extension direction (longitudinal direction) of the bristles.

[0013] According to another aspect of the present invention, the present invention further includes a lever configured to amplify the amount of displacement of the force detection device, the lever including a short arm and a long arm, the long arm contacting one of the first bearing and the second bearing, and a resilient element for resetting the rotating assembly relative to the handle housing disposed therebetween, the short arm contacting the other of the first bearing and the second bearing. The lever rotation axis of the lever is parallel to the pivot axis of the rotating assembly. For a toothbrush head, the lever and the pivot axis of the rotating assembly are substantially perpendicular to the direction in which the bristles on the brush head extend.

[0014] According to another aspect of the present invention, the pivot axis of the rotating assembly passes through the first bearing, and the second bearing is movably arranged relative to the handle housing. The personal care appliance also includes a lever configured to amplify the displacement of the force detection device, the lever including a short arm and a long arm, the short arm contacting the second bearing, and the long arm extending away from the drive shaft; a magnet for the force detection device is provided at the distal end of the long arm, and the inductor is disposed on a circuit board stationary relative to the handle housing, with the magnet opposing the inductor across the circuit board.

[0015] According to yet another aspect of the present invention, the magnet includes a permanent magnet and an electromagnet.

[0016] In addition, the present invention also provides a personal care appliance, comprising: a handle housing; a rotating assembly, wherein the rotating assembly includes a force-bearing element extending outward relative to the handle housing, and when the force-bearing element is subjected to external force, the rotating assembly can rotate relative to the handle housing; and a force detection device, the force detection device is configured to detect the force on the force-bearing element; wherein the force detection device includes a first inductor, a second inductor and a mutual inductor, wherein the first inductor and the second inductor respectively include a magnetic core and a conductor surrounding the magnetic core, and the mutual inductor moves relative to the first inductor and the second inductor in the external magnetic flux of the first inductor and the second inductor to cause a change in the mutual inductance of the first inductor and the second inductor.

[0017] The "mutual inductance element" here refers to a component that can change the coupling coefficient between multiple detection inductance elements by moving in the external magnetic flux of multiple inductance elements. The mutual inductance between multiple inductance elements changes due to the movement of the external magnetic flux of the inductance elements through mutual inductance. Compared with the existing method of using self-inductance changes for force measurement, using mutual inductance changes can more accurately and clearly indicate displacement changes and reflect the magnitude of external force.

[0018] According to another aspect of the present invention, the first inductor and the second inductor are arranged on a control circuit board arranged stationary relative to the handle housing, and the mutual inductor is arranged on the rotating assembly; the personal care appliance also includes an elastic element for resetting the rotating assembly relative to the handle housing.

[0019] According to another aspect of the present invention, the mutual inductance member includes a magnetic conductor, which is made of a material with a relative magnetic permeability of at least 10, and is arranged to form magnetic cores relative to the first inductor and the second inductor, respectively; the magnetic conductor is arranged to displace relative to the first inductor and the second inductor in the external magnetic flux of the inductor as the rotating component rotates.

[0020] According to another aspect of the present invention, the magnetic conductor is U-shaped and includes two arms and a bridge between the arms, and the two arms face the first inductor and the second inductor respectively.

[0021] According to another aspect of the present invention, the mutual inductance element includes a magnetic isolation body, which is made of a material with a relative magnetic permeability less than 1, and the polarities of the remote magnetic poles of the first inductor device and the second inductor device are opposite. The magnetic isolation body is configured to move between the first inductor device and the second inductor device, and can move to a position to block the external magnetic flux between the first inductor device and the second inductor device.

[0022] According to another aspect of the present invention, the rotating assembly also includes a DC motor, the force-bearing element is a drive shaft or brush head driven by the DC motor, the mutual inductor is arranged on a support member installed at one end of the motor away from the drive shaft, and the elastic element is arranged on the support member.

[0023] According to another aspect of the present invention, the personal care appliance also includes a resonant component and a coil component fixedly mounted relative to the handle housing, the resonant component includes a permanent magnet, a permanent magnet bracket for mounting the permanent magnet, and a drive shaft used as a force-bearing element or connecting the force-bearing elements, and the personal care appliance also includes a first bearing and a second bearing, the first bearing being closer to the drive shaft relative to the second bearing, the first bearing and the second bearing being arranged to allow the resonant component to rotate back and forth relative to the handle housing around the axis of the drive shaft when the magnetic lines of force of the permanent magnet cut the current carried by the coil component; wherein the rotating component includes a first bearing, a second bearing and a drive shaft, and when an external force is applied to the force-bearing element, the rotating component can rotate around a pivot axis, which passes through one of the first bearing and the second bearing and is perpendicular to the rotation axis of the drive shaft, and the other of the first bearing and the second bearing is movably arranged relative to the handle housing.

[0024] According to another aspect of the present invention, a lever configured to amplify the displacement of the force detection device is provided on the rotational assembly. The lever includes a short arm and a long arm. The short arm contacts the other of the first and second bearings, and the long arm extends toward one of the first and second bearings. A mutual inductance member is provided on the long arm of the lever. The first and second inductors are mounted on an inductor circuit board that is stationary relative to the handle housing. A resilient element for resetting the rotational assembly is provided between the long arm and one of the first and second bearings. Typically, the lever's rotation axis is parallel to the rotational bearing of the rotational assembly.

[0025] According to another aspect of the present invention, the inductor circuit board is arranged perpendicular to the pivot axis passing through the first bearing, the first inductor component and the second inductor component are arranged on the inductor circuit board at a distance, and the mutual inductance element includes a magnetic conductor or a magnetic shield.

[0026] According to another aspect of the present invention, a lever configured to amplify the displacement of the force detection device is provided on the rotating assembly, the lever including a short arm and a long arm, the short arm contacts the other movably arranged bearing of the first bearing and the second bearing, and the long arm extends away from one of the first bearing and the second bearing.

[0027] According to another aspect of the present invention, the first inductor device and the second inductor device are arranged on the inductor circuit board, the long arm of the lever moves relative to the surface of the inductor circuit board, and auxiliary magnetic conductors are respectively provided on the first inductor device and the second inductor device, so that the magnetic lines of force generated by the first inductor device itself and the magnetic lines of force generated by the second inductor device itself basically face each other, and the magnetic lines of force are roughly perpendicular to the movement direction of the mutual inductance member.

[0028] In addition, the present invention also provides a personal care appliance, comprising: a handle housing; a rotating assembly, wherein the rotating assembly includes a force-bearing element extending outward relative to the handle housing, and when the force-bearing element is subjected to external force, the rotating assembly can rotate relative to the handle housing; and a force detection device, the force detection device is configured to detect the external force applied to the force-bearing element, the force detection device includes a first element and a second element that move relative to each other, the first element is movably mounted relative to the handle housing, and the second element is mounted to be fixed relative to the handle housing; wherein the personal care appliance also includes a lever assembly, the lever assembly includes a pivot portion and a lever, the lever has a long arm and a short arm, the short arm of the lever is attached to the end of the rotating assembly opposite to the force-bearing element, and the first element is mounted on the long arm.

[0029] By providing the lever assembly, the displacement between the relatively moving elements in the force detection device in the personal care appliance is larger than that without the lever assembly, so that the measurement accuracy of the external force is higher and the response is more sensitive.

[0030] According to another aspect of the present invention, the personal care appliance further includes: a handle housing; and a rotating assembly, wherein the rotating assembly includes a force-bearing element extending outward relative to the handle housing, and when the force-bearing element is acted upon by an external force, the rotating assembly can rotate relative to the handle housing; the short arm contacts the end of the rotating assembly away from the force-bearing element, and the lever assembly further includes an elastic element for resetting.

[0031] According to another aspect of the present invention, the personal care appliance also includes a resonant component and a coil component fixedly mounted relative to the handle housing, the resonant component including a permanent magnet, a permanent magnet bracket for mounting the permanent magnet, and a drive shaft used as a force-bearing element or connecting the force-bearing elements, wherein the rotating component includes at least one bearing and a drive shaft held by the bearing, the bearing being arranged to allow the resonant component to reciprocate relative to the handle housing around the axis of the drive shaft when the magnetic lines of force of the permanent magnet cut the current-carrying current of the coil component, when external force is applied to the force-bearing element, the rotating component can rotate around a pivot axis, which passes through at least one bearing and is perpendicular to the rotation axis of the drive shaft, and the pivot axis of the rotating component is parallel to the lever rotation axis of the lever.

[0032] According to another aspect of the present invention, the personal care appliance further comprises a first bearing and a second bearing, the first bearing being closer to the drive shaft than the second bearing, the pivot axis of the rotating assembly passing through one of the first bearing and the second bearing, the other of the first bearing and the second bearing being movable relative to the handle housing, and the short arm contacting the other bearing.

[0033] According to another aspect of the present invention, the pivot bearing passes through the first bearing, the second bearing is movable relative to the handle housing, the short arm contacts the second bearing, and the lever assembly further includes an elastic element for resetting, which is arranged between the long arm and the first bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] For a more complete understanding of the present invention, reference may be made to the following description of exemplary embodiments considered in conjunction with the accompanying drawings, in which:

[0035] FIG1 shows a perspective view of an electric toothbrush according to a first embodiment of the present invention.

[0036] FIG2 is a perspective view showing the internal structure of an electric toothbrush according to a first embodiment of the present invention.

[0037] FIG3 is a partially enlarged perspective view of a force detection device of an electric toothbrush according to a first embodiment of the present invention.

[0038] FIG4 is a partially enlarged perspective view of a force detection device of an electric toothbrush according to a second embodiment of the present invention.

[0039] FIG. 5 is a coordinate diagram showing the relationship between magnetic flux and inductance involved in the force detection device according to the first embodiment and the second embodiment.

[0040] FIG6 is a perspective view showing the internal structure of an electric toothbrush according to a third embodiment of the present invention.

[0041] FIG7 shows a perspective view of the internal structure of an electric toothbrush according to a third embodiment of the present invention from another perspective.

[0042] FIG8 is a perspective view showing the internal structure of an electric toothbrush according to a third embodiment of the present invention, wherein the entire handle housing and components on the rear side of the force detection device are removed.

[0043] FIG9 shows a perspective view of an electric toothbrush according to a fourth embodiment of the present invention.

[0044] FIG10 is a perspective view showing the internal structure of an electric toothbrush according to a fourth embodiment of the present invention.

[0045] FIG11 is a partially enlarged perspective view showing the internal structure of an electric toothbrush according to a fourth embodiment of the present invention.

[0046] FIG12 shows a perspective view of a force detection device of an electric toothbrush according to a fourth embodiment of the present invention.

[0047] FIG13 shows a perspective view of a force detection device of an electric toothbrush according to a fifth embodiment of the present invention.

[0048] FIG14 shows a perspective view of a force detection device of an electric toothbrush according to a fifth embodiment of the present invention from another perspective.

[0049] FIG15 shows a perspective view of a force detection device of an electric toothbrush according to a sixth embodiment of the present invention.

[0050] FIG16 shows a perspective view of a partial internal structure of an electric toothbrush according to a seventh embodiment of the present invention.

[0051] FIG17 shows a perspective view of a force detection device of an electric toothbrush according to a seventh embodiment of the present invention.

[0052] 18 and 19 are schematic diagrams showing circuit diagrams according to preferred embodiments of the present invention.

[0053] FIG20 shows a circuit diagram of the second embodiment.

[0054] : Reference numerals: 1, 201, 301 Brush head 2, Handle device 4, 240 Control circuit board 5, Rotating assembly 11, 311 Cleaning element 21, 221, 321 Handle housing 31, 231 Rotating pivot 32, 232, 332, 632 Drive shaft 33, Interface part 34, Gear box cover 35, Gear box 41, 241, 341, 441, 641 First inductor 42, 242, 342, 442, 642 Second inductor 51, 151, 251 DC micro motor 52, 152, 252 Support part 53, Motor circuit board 55, 155, 255, 355, 655 Coil spring 57, 657 First magnet 58, 658 Second magnet 150 Permanent magnet 250 Magnetizer 310 Permanent magnet 311 Coil assembly 313, 413 First bearing 314, 614, second bearing 330, 430, 530, 630, lever 333, magnetic conductor 336, lever pivot 346, 347, auxiliary magnetic conductor 451, 551, inductor circuit board 455, magnetic isolation L1', L2', inductor C in the circuit, resonant capacitor R, sampling resistor Ui, input voltage Uo, output voltage I / O, A / D sampling port W1 of MCU, when F1>F2, the rotation direction of the first rotating component is W2, when F2>F1, the rotation direction of the first rotating component is W3, the central axis W4 of the driving shaft, the longitudinal direction W5 of the cleaning element, the pivot axis W6, the direction of reciprocating rotation of the second bearing 214 around W5 is shown as F1, which is the external force F2 applied to the bristles, the elastic force F3 generated by the elastic element, and the elastic force generated by the elastic element of the motor. DETAILED DESCRIPTION

[0055] The present invention is further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0056] In the following description, the term "front end / front side" refers to the end or side where the cleaning elements of the brush head of the electric toothbrush are located, and the term "rear end / rear side" refers to the end or side where the cleaning elements of the brush head of the electric toothbrush are located away from the electric toothbrush.

[0057] FIG1 shows a perspective view of an electric toothbrush according to a first embodiment of the present invention, wherein the driving device of the electric toothbrush is a DC micromotor 51. As shown in FIG1 , the electric toothbrush mainly includes a brush head 1 and a handle device 2. The brush head 1 is provided with a cleaning element 11 such as bristles on its force-applying portion. The brush head 1 is mounted on a drive shaft extending forward from the handle device 2, which serves as a force-bearing element, through form-fitting. When the brush head 1 is mounted on the handle device 2, it can be understood that the brush head 1, particularly the portion thereof provided with the cleaning element, becomes the force-bearing element of the electric toothbrush.

[0058] The handle assembly 2 of an electric toothbrush primarily comprises a handle housing 21 and an internal mechanism. For an electric toothbrush driven by a DC micromotor 51, the internal mechanism primarily comprises the DC micromotor 51, a gearbox 35, a gearbox cover 34, a drive shaft 32, an interface 33 located on the gearbox cover 34, a control circuit board 4, a motor circuit board 53 on which the DC micromotor 51 is mounted, and a force detection device.

[0059] In the present invention, a portion of the components within the internal mechanism of the electric toothbrush are fixedly connected together to form a rotating assembly that can rotate relative to the handle housing. When a force is applied to the cleaning element 11 of the brush head 1 during use, the rotating assembly rotates about the pivot 31. As the rotating assembly moves, the force detection device detects the external force applied to the cleaning element 11. Typically, the external force being detected is applied along the longitudinal direction of the cleaning element 11.

[0060] In the first embodiment, the rotating assembly 5 primarily comprises a drive shaft 32 for mounting the brush head within the internal mechanism, an interface member 33, a gearbox cover 34, a gearbox 35, a DC micromotor 51, a support member 52, and a motor circuit board 53. Once installed, these components are stationary relative to one another. The drive shaft 32 and interface member 33 extend from a hole in the front end of the handle housing 1, while the other components of the rotating assembly are housed within the handle housing. A pair of pivots 31 are provided on the gearbox cover 34, preferably extending integrally from the gearbox cover 34 in opposite directions. These pivots 31 provide a pivot point for the rotating assembly 5, and upon receiving force, the rotating assembly rotates about the pivots 31.

[0061] 7 , preferably, a rotating assembly bracket 61 is disposed within the handle housing 21. The rotating assembly bracket 61 is stationary relative to the handle housing 21. The rotating assembly bracket 61 is provided with a pivot hole or recess adapted to be rotatably coupled to the rotating pivot 31. Thus, when subjected to an external force, the rotating assembly 5 rotates relative to the rotating assembly bracket 61, thereby also rotating relative to the handle housing 21. In other alternative embodiments, the handle housing may replace the rotating assembly bracket.

[0062] In order to return the rotating assembly to its initial position after the external force is removed, a resilient element is provided between the rotating assembly 5 and the rotating assembly bracket 61. In a preferred embodiment, the resilient element is a coil spring 55, as shown in FIG3 . The resilient element is constrained by the rotating assembly bracket 61 on the one hand, and is also constrained by the rotating assembly bracket 61 on the other hand. Specifically, one end of the coil spring 55 is attached to the contact end of the first rotating assembly bracket 61, while the other end of the coil spring 55 is attached to the support member 52 provided in the rotating assembly 5. In this way, the coil spring 55 provides an elastic and movable connection between the rotating assembly bracket 61 and the rotating assembly 5, and the coil spring 55 can perform elastic telescopic movement along the axis of its cylindrical shape. In the first embodiment, the support member 52 is fixed to the tail of the motor 51 together with the motor circuit board 53. The motor circuit board 53 and the related wires realize the electrical connection between the DC micromotor 51 and the control circuit board 4.

[0063] In the first embodiment, the handle device 2 of the electric toothbrush is also specially provided with a force detection device for detecting the external force applied to the brush head and providing a warning when the external force exceeds a threshold value. In the first embodiment, as shown in Figure 3, the force detection device includes a pair of permanent magnets and a pair of inductors. The paired magnets are a first magnet 57 and a second magnet 58, and the two magnets 57 and 58 are fixedly mounted on the support member 52 at a distance. The first inductor 41 and the second inductor 42 are welded to the control circuit board, and the control circuit board is stationary relative to the handle housing. The two inductors 41 and 42 are also separated from each other, and the separation distance is basically equal to the distance between the magnets 57 and 58, so that the first magnet 57 is opposite to the fixed magnetic core in the first inductor, and the second magnet 58 is opposite to the fixed magnetic core in the second inductor.

[0064] The inductive device in the present invention specifically refers to an inductive device comprising a fixed magnetic core and a conductive body wound around the fixed magnetic core. For example, an inductor is formed by winding a plurality of turns of a coil around a magnetic core made of ferrite; another example is the chip inductor widely used in the market; or an inductive device is formed by a coil with a hollow structure, a magnetic core made of ferrite is added to the hollow part, and the magnetic core and the coil with a hollow structure are relatively stationary. The fixed magnetic core in the inductive device can also be composed of a number of magnetic beads or silicon steel sheets. The inductive device can also be the widely used chip ferrite beads, inductors, chip very high frequency inductors, and chip inductors with a multilayer ferrite core (multilayer chip inductor).

[0065] When the brush head 1 is guided by an external force to rotate the rotating assembly about the rotating pivot 31, the first magnet 57 and the second magnet 58 approach the first inductor 41 and the second inductor 42. During this process, the magnetic flux generated by the first magnet 57 and passing through the magnetic core of the first inductor 41 can cause the magnetic core of the first inductor 41 to enter a magnetic saturation state. Similarly, the magnetic flux generated by the second magnet 58 and passing through the magnetic core of the second inductor 41 can cause the magnetic core of the second inductor 41 to enter a magnetic saturation state.

[0066] According to the physical definition of the self-inductance of an inductor, L1 = φ / I, where L1 is the self-inductance of the inductor, I is the current flowing through the inductor, and φ is the magnetic flux generated by the inductor. When the inductor's core reaches magnetic saturation, an increase in the inductor coil current fails to generate a corresponding amount of magnetic flux. The inductor core then enters magnetic saturation, and the self-inductance rapidly decreases, as shown in the curve in Figure 5. Utilizing the accelerated change in self-inductance allows for a more rapid and accurate response to applied external forces.

[0067] In the first embodiment, the first magnet 57 and the second magnet 58 can be arranged so that when the first magnet 57 and the second magnet 58 are closest to the first inductor 41 and the second inductor 42, the fixed magnetic cores of the first inductor 41 and the second inductor 42 enter a magnetic saturation state, or the magnetic saturation state of the fixed magnetic cores is intensified; and when the first magnet 57 and the second magnet 58 are farthest from the first inductor 41 and the second inductor 42, the fixed magnetic cores of the first inductor 41 and the second inductor 42 exit a magnetic saturation state, or the degree of magnetic saturation of the fixed magnetic cores is reduced. The above-mentioned "closest" means that under the combined action of the external force F1 and the elastic force F2 (as shown in FIG2 ) (F1>F2), the first magnet 57 and the second magnet 58 are closest to the first inductor 41 and the second inductor 42 as the first rotating assembly 5 moves. The term "farthest away" as used above refers to the situation where, under the combined action of external force F1 and elastic force f2 (F1 < F2), first magnet 57 and second magnet 58 are furthest away from first inductor 41 and second inductor 42 as first rotating assembly 5 moves. By adjusting the volume, size, or surface residual magnetic strength of first magnet 57 and second magnet 58, as well as the distance between first magnet 57 and second magnet 58 and the magnetic core of first inductor 41 and second inductor 42, the magnetic cores of inductors 41 and 42 can enter and exit magnetic saturation, or the degree of magnetic saturation of the magnetic cores can be varied, within the displacement range of first magnet 57 and second magnet 58. The term "magnetic saturation of the magnetic core" here refers to the decrease in inductance of the inductor from its nominal inductance under the action of an external magnetic flux, while the term "nominal inductance" refers to the inductance of the inductor when no external magnetic field is present and no current is flowing through the inductor.

[0068] 5 , point 0 represents the fixed core of the inductor device being unsaturated, point A represents the initial saturation critical point of the core of the inductor device, the inductance corresponding to points 0 and A are both nominal inductances, the internal magnetic flux of the core corresponding to point A is Φ1, and the OA segment represents the fixed core of the inductor device being in a magnetically unsaturated state. The AB segment represents the core of the inductor device entering a preliminary saturation state. In the example of FIG5 , point B is set as the fixed core moderate saturation critical point, preferably set to a corresponding inductance of 70% of the nominal inductance, and the internal magnetic flux of the fixed core corresponding to point B is Φ2. The BC segment represents the fixed core of the inductor device entering a moderate saturation state. In the example of FIG5 , point C is set as the fixed core deep saturation critical point, preferably set to a corresponding inductance of 20% of the nominal inductance, and the internal magnetic flux of the core corresponding to point C is Φ3. When the magnetic flux inside the core is greater than Φ3, the inductor core enters a deep saturation state. Segment CD represents this deep saturation state. Furthermore, point D represents the fixed core's full magnetic saturation point. At this point, the fixed core is in a full magnetic saturation state, and even if the external magnetic field increases, the magnetic flux inside the fixed core no longer increases. It should be noted that the ratio of nominal inductance represented by points B and C is merely an example and can be modified based on the characteristics of the selected inductor. In other alternative embodiments, the fixed core's moderate saturation threshold point B can be set so that the fixed core's magnetic state results in an inductance between 60% and 80% of the nominal inductance; while the fixed core's deep saturation threshold point can be set so that the fixed core's magnetic state results in an inductance between 10% and 30% of the nominal inductance. Overall, the rate of change of the inductor's inductance with the fixed core's internal magnetic flux in segment BC is significantly greater than the corresponding rates of change in segments AB and CD. Preferably, the volume, size, or surface residual magnetic strength of the first and second magnets 57, 58, as well as the distances between the first and second magnets 57, 58 and the fixed cores of the first and second inductors 41, 42, are set such that, when magnets 57, 58 are closest to their respective opposing inductors 41, 42, the magnetic flux generated by magnets 57, 58 through the fixed cores of the inductors 41, 42 is greater than Φ2 and less than Φ3. More preferably, the magnetic flux generated by the magnets during movement and passing through the inductor cores is greater than Φ2 and less than Φ3. The fixed core entering a magnetic saturation state refers to the magnetic state of the fixed core moving from a point in the 0A segment in FIG5 along the curves of segments OA and AD, past point A, toward point D. The core exiting a magnetic saturation state refers to the magnetic state of the core moving from a point in the AD segment in FIG5 along the curves of segments DA and AO, past point A, toward point O. The aggravation of the magnetic saturation state of the magnetic core means that the magnetic saturation state of the magnetic core moves from a certain point in the AD segment in FIG. 5 toward point D along the curve of the AD segment.The said slowing down of the magnetic saturation state of the magnetic core means that the magnetic saturation state of the magnetic core moves from a certain point in the AD segment in FIG. 5 toward point A along the curve of the DA segment.

[0069] 18 and 19 show circuit arrangements related to the first inductor 41 and the second inductor 42 .

[0070] As shown in Figure 19, the first inductor 41 corresponds to the inductor L1', and the second inductor 42 corresponds to the inductor L2'. The two inductors L1' and L2' are connected in series with each other and with the resonant capacitor C and the sampling resistor R. The total inductance of the two inductors L1' and L2' and the resonant capacitor C can form an LC resonant circuit or a resonance circuit. A sine wave or rectangular wave with a preset frequency f0 is input to the input end of the circuit, and the voltage Uo on the sampling resistor is rectified and filtered. The IO port of the MCU is used for AD sampling to collect the value of the voltage on the sampling resistor and detect the voltage change on the sampling resistor. Obviously, F1 applied to the cleaning element of the brush head 1 can change the distance between the magnet and the inductors 41 and 42, thereby affecting the total inductance L of the detection circuit, thereby affecting the voltage Uo on the detection sampling resistor R. Furthermore, the MCU can equivalently identify the size of the external force F1 applied to the cleaning element 11 by identifying different voltage values ​​on the sampling resistor R, thereby realizing the detection of the size of the external force applied to the bristles (cleaning element) 11. When the external force F1 is too small (for example, <1.5N), the MCU can output a signal that the force is too small, such as by LED display, or by sound reminder. Similarly, when the external force F1 is within a suitable range (for example, 1.5N-2.5N), the MCU can output a signal of appropriate force size, such as LED display or sound reminder. Similarly, when the external force F1 is greater than the set value (such as 2.5N), the MCU can output a signal that the force is too large, which can also be displayed by LED or sound reminder. Obviously, the sampled voltage can also come from U in Figure 19. 01 , that is, sampling the total voltage on the resistor R and the capacitor C, can also achieve the above-mentioned detection function, which will not be repeated here.

[0071] The detection circuit shown in FIG18 is similar to the detection circuit shown in FIG19 . The difference between the two lies in the LC resonant circuit. FIG18 is an LC parallel resonant circuit, while FIG19 is an LC series resonant circuit. FIG18 can also realize the above-mentioned detection function.

[0072] FIG4 shows a second embodiment of the present invention, which relates to an electric toothbrush using a DC micro motor 151 , wherein the main structure of the rotating assembly is the same as that of the first embodiment and will not be described again here.

[0073] The difference from the first embodiment is that the force detection device in the second embodiment includes only one permanent magnet 150 and only one inductor 140. The permanent magnet 150 is preferably disposed in the hollow portion of the coil spring 155, that is, the coil spring 155 surrounds the permanent magnet 150. However, the permanent magnet 150 and the coil spring 155 may also be disposed separately. The permanent magnet 150 and the coil spring 155 are disposed together on a support member 152 fixed to the rear end of the motor 151.

[0074] The operating principle of the force detection device of the second embodiment is the same as that of the first embodiment. Both utilize the principle that after the magnet 150 causes the magnetic core of the inductor 140 to enter a state of magnetic saturation, the inductance decreases at an accelerated rate, thereby more accurately detecting the external force applied to the brush head 1. Figure 20 shows the circuit diagram of the second embodiment, in which a single inductor L is connected in series with a resonant capacitor C and a sampling resistor R, which also achieves the above-mentioned detection function.

[0075] In the first and second embodiments described above, permanent magnets may also replace electromagnets such as energized coils, as long as these electromagnets can also provide a way to pass through the fixed magnetic core of the inductor device and cause the fixed magnetic core of the inductor device to enter and exit the magnetic saturation state, or to intensify the magnetic saturation state of the fixed magnetic core of the inductor device and relieve the magnetic saturation state of the fixed magnetic core of the inductor device in the AD section after the fixed magnetic core enters the magnetic saturation state as shown in FIG. 5 .

[0076] Figures 6 to 8 show a third embodiment of the present invention. In the third embodiment, inside the handle housing 221, the force detection device arranged on the rear side of the motor 251 includes a magnetizer 250, wherein the magnetizer 250 is made of a material with a relative magnetic permeability of at least 10, such as a ferrite or silicon steel sheet or other high magnetic permeability material. In the third embodiment, as shown in Figure 8, the magnetizer 250 is U-shaped, including two arms and an intermediate bridge portion, the two arms facing the fixed magnetic cores of the first inductor 241 and the second inductor 242 respectively, and there is a movement gap between the end faces of the arms and the fixed magnetic cores. The magnetizer 250 is fixed to the support member 252 by glue, for example, through a dovetail groove provided on the intermediate bridge portion.

[0077] The two inductors 241 and 242 in the third embodiment are the same as those in the first embodiment, and refer to inductive devices including a fixed magnetic core and a conductor wrapped around the fixed magnetic core. The first inductor 241 and the second inductor 242 are fixed on a control circuit board 240 that is stationary relative to the handle housing 221, and form respective remote magnetic poles in a direction away from the control circuit board 240. At the same time, the polarity of the respective remote magnetic poles generated by the current passing through the first inductor 241 and the second inductor 242 is opposite. For example, the remote magnetic pole of the first inductor 241 is the N pole, and the remote magnetic pole of the second inductor 242 is the S pole. In other alternative embodiments, the remote magnetic poles of the first inductor 241 and the second inductor 242 can also be of the same polarity.

[0078] In the third embodiment, the magnetizer 250 moves as the external force applied to the brush head 201 or the drive shaft 232 moves, and the magnetizer 250 moves in the external magnetic flux of these inductors 241, 242, thereby changing the coupling coefficient between the two inductors 241, 242, causing the mutual inductance between the inductors 241, 242 to change, thereby enabling the external force to be detected.

[0079] Specifically, the external magnetic flux generated by the current of the first inductor 241 itself will pass through the fixed magnetic core of the second inductor 242, forming the mutual inductance of the first inductor 241 to the second inductor 242. Similarly, the second inductor 242 will also generate mutual inductance to the first inductor. There is an external magnetic circuit between the first inductor 241 and the second inductor 242. The magnetic resistance of the external magnetic circuit will affect the size of the magnetic flux entering from one inductor to another. The magnetic resistance of the external magnetic circuit affects the coupling coefficient k between the two inductors. The smaller the magnetic resistance of the external magnetic circuit, the closer the coupling coefficient k between the inductors is to 1. The magnetic resistance of the magnetic conductor is much smaller than that of the air. The closer the magnetic conductor 250 is to the first inductor 241 and the second inductor 242, the faster the coupling coefficient k between the first inductor 241 and the second inductor 242 will increase. According to the principles of physics,

[0080] In the formula, M 12 is the mutual inductance of the first inductor 241 and the second inductor 242, k is the coupling coefficient between the two inductors, and is applied to the third embodiment, L1 is the self-inductance of the first inductor 241, and L2 is the self-inductance of the second inductor 242. Similarly, the mutual inductance of the first inductor 241 to the second inductor 242 is M 21 , and M 12 =M 21 .

[0081] As shown in Figures 18 and 19, the total inductance L of the inductive load in the detection circuit is expressed as follows: L = L1 + L2 + 2*M 12 .

[0082] The two arms of the magnetic conductor 250 are respectively opposite to the first inductor 241 and the second inductor 242. When the magnetic conductor 250 approaches or moves away from the first inductor 241 and the second inductor 242, the coupling coefficient between the two inductors 241 and 242 is affected, thereby affecting the mutual inductance between the two inductors 241 and 242. Furthermore, when the magnetic conductor 55 approaches or moves away from the inductors 241 and 242, the total inductance L formed by the combination of the first inductor 241 and the second inductor 242 in the circuit is affected. M12 can be either positive or negative, depending on the direction of the external magnetic flux and the internal magnetic flux of the inductors 241 and 242, with the same direction being positive and the opposite direction being negative.

[0083] When an external force F1 is applied to the brush head 1, and the torque generated by F1 relative to the rotating pivot 231 is greater than the torque generated by the elastic force F2 of the coil spring 255 relative to the rotating pivot 231, the rotating assembly 5 will rotate around the rotating pivot 231 in the direction W1 (see Figure 2). The coil spring 255 located on the support member 252 tends to be compressed or further compressed. The magnetic conductor 250 located on the rotating assembly approaches the far magnetic poles of the first inductor 42 and the second inductor 41 on the control circuit board 4, and the total inductance in the circuit shown in Figures 18 and 19 increases. When the elastic force F2 of the coil spring 255 is greater than F1, the rotating assembly 5 will rotate around the first rotating pivot 231 in the direction W2 (see Figure 2), and the magnetic conductor 250 moves away from the far magnetic poles of the first inductor 241 and the second inductor 242 on the control circuit board 240, and the total inductance in the circuit decreases.

[0084] The specific application of the circuits shown in FIG18 and FIG19 is the same as that described in the first embodiment and will not be repeated here.

[0085] Figures 9 to 12 illustrate a fourth embodiment of the present invention. Unlike the previous embodiments, as shown in Figure 10, this electric toothbrush includes a permanent magnet 310 and a coil assembly 311 located within a handle housing 321. The magnetic flux lines of the permanent magnet 310 cut the current carried by the coil assembly 311, causing the resonant elastic element fixed to the permanent magnet 310 and the mechanical components used to implement the resonant assembly (forming a resonant assembly) to cause the permanent magnet 310 to reciprocate around the axis of a drive shaft 332. The mechanical components of the resonant assembly include components that can move relative to the handle housing, such as the permanent magnet 310 and a permanent magnet bracket for mounting the permanent magnet 310. The drive shaft 332 is connected to the brush head 301 in a form-fitting manner and drives the cleaning element 311 to reciprocate around the centerline axis W3 of the drive shaft 313. In the electric toothbrush of this fourth embodiment, either the drive shaft 332 or the brush head 301 can be considered as force-bearing elements. Patent document CN104617732B discloses an electric toothbrush having a similar resonant component, and the relevant content of this patent document is cited here for reference.

[0086] As shown in Figure 11, the electric toothbrush also includes a first bearing 313 and a second bearing 314 spaced apart along the central axis W3 of the drive shaft 332. The first bearing 313 is closer to the force-bearing element than the second bearing 314. The drive shaft 332 is secured to these two bearings 313 and 314, thereby forming a rotating assembly of the electric toothbrush. This rotating assembly rotates about a pivot axis W5 passing through the first bearing 313 near the brush head. The first bearing 313 includes inner and outer rings and balls arranged therein. The outer ring is stationary relative to the handle housing, while the inner ring is movable relative to the handle housing. When an external force is applied perpendicular to the axis of the drive shaft along the longitudinal direction W4 of the cleaning elements 311 on the brush head, the first bearing 313 provides a pivot axis for the rotating assembly. Specifically, the pivot axis W5 passes through the first bearing 313. In some specific embodiments, the pivot axis W5 passes through the diametrically opposed balls of the first bearing. In a preferred embodiment, the axis W5 passes through the geometric center point of the first bearing 313 and is substantially perpendicular to the longitudinal direction W4 of the cleaning elements 311 on the brush head and perpendicular to the central axis W3 of the drive shaft 332 .

[0087] As shown in FIG10 , the first bearing 313 is fixedly mounted to the left transducer housing 316 and the right transducer housing 317. The left transducer housing 316 and the right transducer housing 317 are mounted inside the handle housing so as to be stationary relative to the handle housing. That is, the outer ring of the first bearing 313 is stationary relative to the handle housing, while the second bearing 314 is movable relative to the left and right transducer housings or the handle housing. The rotational movement of the second bearing 314 is represented by W6 in FIG12 . The force detection device in the first, second and third embodiments can be arranged near the second bearing 314. As the rotating assembly rotates around the axis W5, a displacement is generated between two relatively movable elements (e.g., a magnet and an inductor or a magnetic conductor and an inductor) in the force detection device, thereby indicating whether the force on the force-bearing element exceeds a threshold.

[0088] In this type of electric toothbrush, the length of the lever arm on the side of the pivot axis W5 away from the force-bearing element in the rotating assembly is shorter than that of the first embodiment. Generally, the lever arm formed between the first bearing 313 and the second bearing 314 relative to the axis W5 is smaller than the lever arm formed by the force-bearing element relative to the pivot axis W5. When the rotating assembly rotates around the pivot axis W5, the displacement of the second bearing 314 is smaller than the displacement on the force-bearing element. If the force detection device in the first, second and third embodiments is set at the second bearing 314, there may be a problem of insufficient measurement accuracy due to the small displacement relative to the moving element. To solve this problem, the electric toothbrush of the fourth embodiment is provided with a lever assembly to amplify the displacement of the force detection device relative to the moving element.

[0089] Specifically, as shown in FIG11 , the lever assembly includes a lever 330, which is provided with a lever pivot 336 that provides the lever's rotational axis. Lever pivot 336 is, for example, mounted to a transducer housing stationary relative to handle housing 321 or directly connected to handle housing 321. Lever 330 includes a short arm and a long arm. The short arm contacts the second bearing 314, while the long arm is connected to the first bearing 313 via a coil spring 355. Thus, when an external force F1 is applied to the force-bearing element, the rotating assembly rotates about a pivot axis W5, which passes through the first bearing 313 and is substantially parallel to the pivot axis of lever pivot 336. The elastic element fixed to the permanent magnet 310 generates an elastic resistance force F3, while the coil spring 355 generates an elastic force F2. The elastic force F2 is transmitted to the second bearing 314 via the second lever 330. In this way, through the amplification effect of the lever 330, a larger displacement of the relative position component in the force detection device can be obtained on the long arm of the lever 330, thereby achieving more accurate external force measurement.

[0090] Specifically, as shown in Figures 11 and 12, the force detection device includes a relatively movable magnetic conductor 333 and a pair of inductors 341 and 342, wherein the magnetic conductor 333 is fixed to the long arm of the lever 330, that is, the magnetic conductor 333 is movably mounted relative to the handle housing, while the inductors 341 and 342 are stationarily mounted relative to the handle housing, for example, mounted on an inductor circuit board in a stationary position relative to the handle housing. Preferably, the inductor circuit board is fixed to the housing of the transducer. As shown in Figure 12, the direction of movement of the magnetic conductor 333 is approximately parallel to the direction of the magnetic lines of force within the fixed magnetic cores of the first inductor 341 and the second inductor 342. Therefore, as the external force applied to the brush head, the movement of the magnetic conductor 333 in the external magnetic flux of the inductors 341 and 342 will change the coupling coefficient between the inductors 341 and 342, causing the mutual inductance between the inductors 341 and 342 to change, thereby realizing the detection of the external force.

[0091] Preferably, in order to enhance the influence of the magnetic conductor 333 on the external magnetic flux of the inductors 341 and 342, in the fourth embodiment, L-shaped auxiliary magnetic conductors 346 and 347 are installed at the far magnetic poles of the inductors 341 and 342, so that the magnetic lines of force generated by the inductor 341 itself and the magnetic lines of force generated by the inductor 342 itself basically face each other, and the magnetic lines of force of both are roughly perpendicular to the movement direction of the magnetic conductor 333, thereby enhancing the effect of the movement of the magnetic conductor 333 on the mutual inductance between the inductors 341 and 342.

[0092] Figures 13 and 14 show schematic diagrams of a force detection device according to a fifth embodiment of the present invention. Unlike the fourth embodiment, the first and second inductors 441 and 442 are welded to an inductor circuit board 451 located on the side of the lever 430. The inductor circuit board 451 is arranged substantially perpendicular to the pivot axis W5 passing through the first bearing 413 and substantially parallel to the rotation axis W3 of the drive shaft. The inductor circuit board 451 can be connected to the main control circuit board in the electric toothbrush via wires. The two inductors 441 and 442 have opposite polarities in their distal magnetic poles. A magnetic barrier 455 is mounted on the long arm of the lever 430. When the magnetic barrier 455 is inserted into the space between the first and second inductors 441 and 442 as the lever 430 moves, it blocks the external magnetic flux between the two inductors 441 and 442, thereby changing the mutual inductance of the multiple inductors and providing feedback on the external force measurement result. The magnetic barrier 455 is a material with a relative magnetic permeability less than 1. For example, the magnetic barrier 455 can preferably be copper.

[0093] FIG15 is a schematic diagram of a force detection device according to a sixth embodiment of the present invention. First and second inductors 541 and 542 are mounted on the side of a lever 530 using separate inductor PCBs 551. A magnetic conductor similar to that used in the first embodiment is used to influence the mutual inductance between the two inductors 541 and 542.

[0094] In the above embodiment using a mutual inductor, a first inductor and a second inductor are used for illustration. In practice, there may be more than two inductors, and the mutual inductance between multiple inductors will also be affected and changed by the mutual inductor moving within the external flux linkage of the multiple inductors. This will not be further elaborated here.

[0095] Figures 16 and 17 show schematic diagrams of a force detection device according to a sixth embodiment of the present invention. Unlike the fourth and fifth embodiments, where the lever 530 extends from the second bearing toward the front of the electric toothbrush, in the sixth embodiment, the long arm of the lever 630 extends from the second bearing 614 toward the rear of the electric toothbrush, that is, away from the drive shaft 632, while the short arm of the lever 630 remains in contact with the second bearing 614. The lever 630 can be fixed to the transducer housing or the handle housing. A first magnet 657 and a second magnet 658 are mounted at the distal end of the long arm of the lever 630, opposite the first and second inductors 641 and 642 fixed to the back of the circuit board. A coil spring 655 is also provided on the long arm to reset the rotating assembly. These magnets can also be replaced with energized coils. Similar to the function of the magnet relative to the inductor in the first embodiment, the magnet's poles are oriented toward the inductor's internal magnetic field lines. At least when magnets 657 and 658 are closest to the detection inductors 641 and 642, the magnetic flux generated by magnets 657 and 658 passes through the magnetic cores of inductors 641 and 642, causing the fixed magnetic cores of the inductors to enter a state of magnetic saturation. In this embodiment, the magnets can also be replaced with energized coils.

[0096] In the above embodiment, the rotating assembly has a first bearing and a second bearing, wherein the first bearing near the drive shaft provides the pivot axis. This is exemplary. In other alternative embodiments, the rotating assembly pivots through the second bearing farther from the drive shaft, i.e., the second bearing is fixedly mounted relative to the handle housing, while the first bearing is movably mounted relative to the handle housing. Furthermore, in some other alternative embodiments, there may be only one bearing.

[0097] The above description of personal care appliances with force detection devices is based on an electric toothbrush as an example, but it should be understood that the above-mentioned force detection device can be applied to personal care appliances with other uses that require force control, such as facial cleansing and massage, and the brush head can also be transformed into other similar processing heads, such as a massage head.

[0098] Although the present invention is disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modifications, equivalent variations, and modifications made to the above embodiments in accordance with the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A personal care appliance, comprising: Handle housing; A rotating assembly, wherein the rotating assembly comprises a force-bearing element extending outwardly relative to the handle housing, and when the force-bearing element is acted upon by an external force, the rotating assembly can rotate relative to the handle housing; and a force detection device, the force detection device being configured to detect the force on the force-bearing element; It is characterized in that The force detection device comprises an inductor and a magnet, The inductor device comprises a fixed magnetic core and a conductor surrounding the fixed magnetic core, and the magnetic conductor is arranged relative to the fixed magnetic core in the inductor device so as to generate a magnetic flux passing through the fixed magnetic core of the inductor device; The magnet is displaced relative to the inductor as the rotating component rotates, and the inductor can output a signal indicating the rotation angle of the rotating component and further indicating the magnitude of the external force applied to the force-bearing element.

2. The personal care appliance according to claim 1, characterized in that When the magnet is farthest from the inductor, the fixed magnetic core of the inductor is in an unsaturated state. When the magnet rotates with the rotating component and approaches the inductor, the magnetic flux generated by the magnet and passing through the fixed magnetic core causes the fixed magnetic core of the inductor to enter a magnetic saturation state.

3. The personal care appliance according to claim 1, characterized in that When the magnet is located farthest from the fixed magnetic core of the inductor, the fixed magnetic core of the inductor has entered a magnetic saturation state. When the magnet rotates with the rotating assembly and approaches the fixed magnetic core of the inductor, the change of the magnetic flux generated by the magnet passing through the magnetic core intensifies the magnetic saturation state of the fixed magnetic core of the inductor; When the magnet rotates with the rotating assembly and moves away from the fixed magnetic core of the inductor, the change of the magnetic flux generated by the magnet passing through the magnetic core relieves the magnetic saturation state of the fixed magnetic core of the inductor.

4. The personal care appliance according to claim 1, characterized in that When the magnet is located farthest from the fixed magnetic core of the inductor, the fixed magnetic core of the inductor is approximately at a medium saturation critical point. When the magnet is located closest to the fixed magnetic core of the inductor, the magnet causes the fixed magnetic core of the inductor to be approximately at a critical point of deep saturation; When the magnet rotates with the rotating assembly and approaches the fixed magnetic core of the inductor, the change of the magnetic flux generated by the magnet passing through the magnetic core intensifies the magnetic saturation state of the fixed magnetic core of the inductor; When the magnet rotates with the rotating assembly and moves away from the fixed magnetic core of the inductor, the change of the magnetic flux generated by the magnet passing through the magnetic core relieves the magnetic saturation state of the fixed magnetic core of the inductor.

5. The personal care appliance according to any one of claims 1 to 4, characterized in that: The inductor is fixed on a control circuit board that is arranged stationary relative to the handle housing, and the magnet is arranged on the rotating assembly; The personal care appliance further comprises an elastic element for resetting the rotating assembly relative to the handle housing.

6. The personal care appliance according to claim 5, characterized in that The rotating assembly further comprises a DC motor, and the force-bearing element is a driving shaft or a brush head driven by the DC motor. The magnet is arranged on a support member installed on an end of the motor away from the driving shaft, and the elastic element is arranged on the support member.

7. The personal care appliance according to any one of claims 2 to 4, characterized in that: The magnet includes a first magnet and a second magnet, the inductor includes a first inductor and a second inductor, the first magnet moves relative to a fixed magnetic core of the first inductor, and the second magnet moves relative to a fixed magnetic core of the second inductor.

8. The personal care appliance according to claim 5, characterized in that The personal care appliance comprises a resonant component and a coil component fixedly mounted relative to the handle housing, wherein the resonant component comprises a permanent magnet, a permanent magnet bracket for mounting the permanent magnet, and a driving shaft used as a force-bearing element or connecting the force-bearing elements. The personal care appliance further comprises a first bearing and a second bearing, the first bearing being closer to the drive shaft than the second bearing, the first bearing and the second bearing being arranged to allow the resonant assembly to reciprocate relative to the handle housing around the axis of the drive shaft when the magnetic field lines of the permanent magnet cut the current carried by the coil assembly; The rotating assembly includes the first bearing and the second bearing. When an external force is applied to the force-bearing element, the rotating assembly rotates around a pivot axis, and the pivot axis passes through one of the first bearing and the second bearing and is perpendicular to the axis of the drive shaft. The other of the first bearing and the second bearing is movably arranged relative to the handle housing.

9. The personal care appliance according to claim 8, characterized in that Also included is a lever configured to amplify the amount of displacement of the force detection device, the lever including a short arm and a long arm, the long arm contacts the one of the first bearing and the second bearing and an elastic element for resetting the rotating assembly relative to the handle housing is disposed therebetween, the short arm contacts the other of the first bearing and the second bearing that is movably arranged; The lever rotation axis of the lever is substantially parallel to the pivot axis of the rotating assembly.

10. The personal care appliance according to claim 8, characterized in that The pivot axis passes through the first bearing, and the second bearing is movably arranged relative to the handle housing. The personal care appliance further includes a lever configured to amplify the amount of displacement of the force detection device, the lever including a short arm and a long arm, the short arm contacts the second bearing, and the long arm extends toward a side away from the drive shaft; The magnet of the force detection device is disposed at the distal end of the long arm, and the inductor is disposed on a circuit board that is stationary relative to the handle housing. And the magnet is opposite to the inductor device via the circuit board.

11. The personal care appliance according to claim 1, characterized in that The magnets include permanent magnets and electromagnets.

12. A personal care appliance comprising: Handle housing; A rotating assembly, wherein the rotating assembly comprises a force-bearing element extending outwardly relative to the handle housing, and when the force-bearing element is acted upon by an external force, the rotating assembly can rotate relative to the handle housing; and a force detection device, the force detection device being configured to detect force detection on the force-bearing element; It is characterized in that The force detection device includes a first inductor, a second inductor and a mutual inductor. The first inductor and the second inductor respectively include a fixed magnetic core and a conductor surrounding the fixed magnetic core. The mutual inductance element moves relative to the first inductance device and the second inductance device in the external flux linkage of the first inductance device and the second inductance device to cause the mutual inductance of the first inductance device and the second inductance device to change.

13. The personal care appliance according to claim 12, characterized in that The first inductor and the second inductor are arranged on a control circuit board which is arranged stationary relative to the handle housing. The mutual inductance member is arranged on the rotating assembly; The personal care appliance further comprises an elastic element for resetting the rotating assembly relative to the handle housing.

14. The personal care appliance according to claim 12 or 13, characterized in that: The mutual inductance member comprises a magnetic conductor, and the magnetic conductor is made of a material with a relative magnetic permeability of at least 10. The magnetic conductor is arranged to be opposite to the magnetic cores of the first inductor and the second inductor respectively; The magnetic conductor is arranged to be displaced relative to the first inductor and the second inductor in the external flux linkage of the inductor as the rotating component rotates.

15. The personal care appliance according to claim 14, characterized in that The magnetic conductor is U-shaped and includes two arms and a bridge between the arms, and the two arms face the first inductor and the second inductor respectively.

16. The personal care appliance according to claim 12 or 13, characterized in that: The mutual inductance element comprises a magnetic isolation body, the magnetic isolation body is made of a material with a relative magnetic permeability less than 1, and the polarities of the remote magnetic poles of the first inductor and the second inductor are opposite, The magnetic isolation body is arranged to move between the first inductor and the second inductor, and can move to a position for blocking external magnetic flux between the first inductor and the second inductor.

17. The personal care appliance according to claim 13, wherein The rotating assembly further comprises a DC motor, and the force-bearing element is a driving shaft or a brush head driven by the DC motor. The mutual inductance member is arranged on a support member installed on an end of the motor away from the driving shaft, and the elastic element is arranged on the support member.

18. The personal care appliance according to claim 12, wherein: The personal care appliance further comprises a resonant component and a coil component fixedly mounted relative to the handle housing, wherein the resonant component comprises a permanent magnet, a permanent magnet bracket for mounting the permanent magnet, and a drive shaft used as a force-bearing element or connecting the force-bearing elements. The personal care appliance further comprises a first bearing and a second bearing, the first bearing being closer to the drive shaft than the second bearing, the first bearing and the second bearing being arranged to allow the resonant assembly to reciprocate relative to the handle housing around the axis of the drive shaft when the magnetic field lines of the permanent magnet cut the current carried by the coil assembly; The rotating assembly includes the first bearing, the second bearing and the drive shaft. When external force is applied to the force-bearing element, the rotating assembly can rotate around a pivot axis, and the pivot axis passes through one of the first bearing and the second bearing and is perpendicular to the axis of the drive shaft. The other of the first bearing and the second bearing is movably arranged relative to the handle housing.

19. The personal care appliance according to claim 18, characterized in that The rotating assembly is provided with a lever configured to amplify the displacement of the force detection device, the lever includes a short arm and a long arm, the short arm contacts the other movably arranged bearing of the first bearing and the second bearing, the long arm extends toward the one of the first bearing and the second bearing, the mutual inductance member is arranged on the long arm of the lever, the first inductor device and the second inductor device are mounted on an inductor circuit board stationary relative to the handle housing, An elastic element for returning the rotating assembly to its original position is disposed between the long arm and the one of the first bearing and the second bearing. The lever rotation axis of the lever is substantially parallel to the pivot axis of the rotating assembly.

20. The personal care appliance according to claim 18 or 19, characterized in that The inductor circuit board is arranged perpendicular to the pivot axis passing through the first bearing, and the first inductor device and the second inductor device are arranged on the inductor circuit board at a distance. The mutual inductive element includes a magnetic conductor or a magnetic isolation element.

21. The personal care appliance of claim 18, wherein: The rotating assembly is provided with a lever configured to amplify the displacement of the force detection device, the lever including a short arm and a long arm, the short arm contacts the other movably arranged bearing of the first bearing and the second bearing, and the long arm extends away from the one bearing of the first bearing and the second bearing.

22. The personal care appliance of claim 19, wherein: The first inductor and the second inductor are arranged on an inductor circuit board, and the long arm of the lever moves relative to the surface of the inductor circuit board. Auxiliary magnetic conductors are respectively provided on the first inductor and the second inductor, so that the magnetic lines of force generated by the first inductor and the second inductor are basically facing each other, and the magnetic lines of force are roughly perpendicular to the movement direction of the mutual inductor.

23. A personal care appliance comprising: Handle housing; A rotating assembly, wherein the rotating assembly comprises a force-bearing element extending outwardly relative to the handle housing, and when the force-bearing element is acted upon by an external force, the rotating assembly can rotate relative to the handle housing; and A force detection device, the force detection device is configured to detect the external force applied to the force-bearing element, the force detection device comprises a first element and a second element that move relatively, the first element being movably mounted relative to the handle housing, and the second element being fixedly mounted relative to the handle housing; Characterized in that the personal care appliance also includes a lever assembly, the lever assembly includes a pivot A rotating part and a lever, wherein the lever has a long arm and a short arm, the short arm of the lever is attached to an end of the rotating assembly opposite to the force-bearing element, and the first element is installed on the long arm.

24. The personal care appliance of claim 23, wherein: The personal care appliance also includes: handle housing; and A rotating assembly, wherein the rotating assembly comprises a force-bearing element extending outwardly relative to the handle housing, and when the force-bearing element is acted upon by an external force, the rotating assembly can rotate relative to the handle housing; The short arm contacts an end of the rotating assembly away from the force-bearing element, The lever assembly also includes an elastic element for resetting.

25. The personal care appliance of claim 23, wherein: The personal care appliance further comprises a resonant component and a coil component fixedly mounted relative to the handle housing, wherein the resonant component comprises a permanent magnet, a permanent magnet bracket for mounting the permanent magnet, and a drive shaft used as a force-bearing element or connecting the force-bearing elements. The rotating assembly includes at least one bearing and the drive shaft held by the bearing, wherein the bearing is arranged to allow the resonant assembly to reciprocate relative to the handle housing around the axis of the drive shaft when the magnetic field lines of the permanent magnet cut the current carried by the coil assembly. When an external force is applied to the force-bearing element, the rotating assembly rotates around a pivot axis that passes through the at least one bearing and is perpendicular to the rotation axis of the drive shaft, and the pivot axis of the rotating assembly is parallel to the lever rotation axis of the lever.

26. The personal care appliance of claim 25, wherein: The personal care appliance further comprises a first bearing and a second bearing, wherein the first bearing is closer to the drive shaft than the second bearing. The pivot axis of the rotating assembly passes through one of the first bearing and the second bearing, and the other of the first bearing and the second bearing is movable relative to the handle housing. The short arm contacts the other bearing.

27. The personal care appliance of claim 26, wherein: The pivot axis passes through the first bearing, and the second bearing is movable relative to the handle housing. The short arm contacts the second bearing, The lever assembly further comprises an elastic element for resetting, and the elastic element is arranged between the long arm and the first bearing.

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