Personal care appliance

Abstract

The invention discloses a personal care appliance. The personal care appliance comprises a handle shell and a rotating assembly, the rotating assembly comprises a stress element, and when the stress element is subjected to external force, the rotating assembly can rotate relative to the handle shell; the force detection device is configured to detect the force on the stressed element; wherein the force detection device comprises an inductive device and a magnet arranged to generate a magnetic flux through a magnetic core of the inductive device relative to the magnetic core in the inductive device; the position of the magnet relative to the inductive device shifts along with rotation of the rotating assembly, and the inductive device outputs a signal to indicate the rotation angle of the rotating assembly. According to the invention, the inductance device can enter a magnetic core magnetic saturation state under the action of the permanent magnet or the electromagnet, so that the inductance value of the inductance device is accelerated and reduced, and the variation amplitude of the measured value of the force detection device is larger under the same external force, so that the displacement change can be indicated more accurately and clearly, and the external force can be reflected more accurately and clearly.

Description

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 use appropriate pressure to protect gums when brushing has become a growing demand. Currently, there are various solutions on the market to measure the external force applied to the electric toothbrush head. However, since the deflection amplitude of the electric toothbrush head is very limited, the detection accuracy of the external force applied to the brush head in the existing electric toothbrush is poor, the force detection error is relatively large, and only one force threshold can be detected.

[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 of the electric toothbrush is smaller than that of the electric toothbrush that uses 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. Summary of the invention

[0004] 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 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; wherein the force detection device comprises an inductor and a magnet, wherein the inductor comprises 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 rotation angle of the rotating assembly, thereby further identifying the magnitude of the external force on the force-bearing element.

[0005] 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.

[0006] 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, and in the process of the magnet rotating with the rotating component and approaching the fixed magnetic core of the inductor, the change in the magnetic flux generated by the magnet passing through the magnetic core aggravates the magnetic saturation state of the fixed magnetic core of the inductor; in the process of the magnet rotating with the rotating component and moving away from the fixed magnetic core of the inductor, the change in the 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.

[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 is approximately at a critical point of moderate saturation, and when the magnet is located closest to the fixed magnetic core of the inductor, the magnet makes the fixed magnetic core of the inductor approximately at a critical point of deep saturation; in the process of the magnet rotating with the rotating component and approaching the fixed magnetic core of the inductor, the change of the magnetic flux generated by the magnet passing through the magnetic core makes the magnetic saturation state of the fixed magnetic core of the inductor aggravate; in the process of the magnet rotating with the rotating component and away from the fixed magnetic core of the inductor, the change of the magnetic flux generated by the magnet passing through the magnetic core makes the magnetic saturation state of the fixed magnetic core of the inductor slow down. The present invention adopts an inductor that enters a magnetic core magnetic saturation state under the action of a permanent magnet or an electromagnet, so that the inductance of the inductor accelerates to decrease, and the same displacement force detection device can obtain a larger change in the measured value, so that the displacement change can be indicated more accurately and clearly and the external force size can be reflected.

[0008] According to another aspect of the present invention, the inductor 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 also includes an elastic element for resetting the rotating assembly relative to the handle housing.

[0009] 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 a 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.

[0010] 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.

[0011] According to another aspect of the present invention, a personal care appliance includes a resonant component and a coil component fixedly mounted relative to a 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 element, and the personal care appliance also includes a first bearing and a second bearing, the first bearing is closer to the drive shaft than the second bearing, and the first bearing and the second bearing are 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 of the coil component; the rotating component includes a first bearing and a second bearing, when the external force to be measured is applied to the force-bearing element, the rotating component can rotate around a pivot axis, the pivot axis 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. In general, the direction of the external force to be measured is consistent with the longitudinal direction of the cleaning element on the force-bearing element, and for a toothbrush head, the direction of the external force to be measured is consistent with the extension direction (longitudinal direction) of the bristles.

[0012] According to another aspect of the present invention, there is also 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 one of the first bearing and the second bearing, and an elastic element for resetting the rotating assembly relative to the handle housing is arranged between the two, and the short arm contacts 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 the toothbrush head, the lever and the pivot axis of the rotating assembly are substantially perpendicular to the extension direction of the bristles on the brush head.

[0013] 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 contacts the second bearing, and the long arm extends toward a side away from the drive shaft; a magnet of the force detection device is provided at the distal end of the long arm, the inductor is provided on a circuit board that is stationary relative to the handle housing, and the magnet is opposite to the inductor across the circuit board.

[0014] According to still another aspect of the present invention, the magnet includes a permanent magnet and an electromagnet.

[0015] In addition, the present invention also provides a personal care appliance, comprising: a handle shell; a rotating assembly, wherein the rotating assembly includes a force-bearing element extending outward relative to the handle shell, and when the force-bearing element is subjected to external force, the rotating assembly can rotate relative to the handle shell; 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 inductance member, wherein the first inductor and the second inductor respectively include a magnetic core and a conductor surrounding the magnetic core, and the mutual inductance member 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.

[0016] The "mutual inductance element" here refers to a component that can change the coupling coefficient between multiple detection inductance elements when it moves 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 element. Compared with the existing means of measuring force by using changes in self-inductance, using changes in mutual inductance can more accurately and clearly indicate displacement changes and reflect the size of external force.

[0017] 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.

[0018] According to another aspect of the present invention, the mutual inductance element includes a magnetic conductor, which is made of a material with a relative magnetic permeability of at least 10, and is arranged to be a magnetic core relative to 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 magnetic flux of the inductor as the rotating component rotates.

[0019] 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.

[0020] 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 and the second inductor are opposite. The magnetic isolation body is configured to move between the first inductor and the second inductor, and can move to a position to block the external magnetic flux between the first inductor and the second inductor.

[0021] 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 a brush head driven by the DC motor, the mutual inductance member 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.

[0022] 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 is closer to the drive shaft than the second bearing, the first bearing and the second bearing are 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 carried by the coil component; wherein the rotating component includes a first bearing, a second bearing and a drive shaft, when an external force is applied to the force-bearing element, the rotating component can rotate around a pivot axis, the pivot axis 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.

[0023] 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 includes a short arm and a long arm, the short arm contacts the other of the first and second bearings, the long arm extends toward the above one of the first and second bearings, 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, and the elastic element for resetting the rotating assembly is arranged between the long arm and one of the first and second bearings. Usually, the lever rotation axis of the lever is parallel to the rotating bearing of the rotating assembly.

[0024] 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 device and the second inductor device are arranged on the inductor circuit board with a distance therebetween, and the mutual inductance element includes a magnetic conductor or a magnetic shield.

[0025] 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 in the first bearing and the second bearing, and the long arm extends away from one of the first bearing and the second bearing.

[0026] 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.

[0027] In addition, the present invention also provides a personal care appliance, comprising: a handle shell; a rotating assembly, wherein the rotating assembly includes a force-bearing element extending outward relative to the handle shell, and when the force-bearing element is subjected to external force, the rotating assembly can rotate relative to the handle shell; 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 shell, and the second element is mounted to be fixed relative to the handle shell; 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.

[0028] 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.

[0029] According to another aspect of the present invention, the personal care appliance also includes: a handle shell; and a rotating assembly, wherein the rotating assembly includes a force-bearing element extending outward relative to the handle shell, and when the force-bearing element is subjected to external force, the rotating assembly can rotate relative to the handle shell; the short arm contacts the end of the rotating assembly away from the force-bearing element, and the lever assembly also includes an elastic element for resetting.

[0030] 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, the pivot axis 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.

[0031] According to another aspect of the present invention, the personal care appliance also includes a first bearing and a second bearing, 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, the other of the first bearing and the second bearing is movable relative to the handle housing, and the short arm contacts the other bearing.

[0032] 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

[0033] 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:

[0034] Figure 1 A perspective view of an electric toothbrush according to a first embodiment of the present invention is shown.

[0035] Figure 2 A perspective view showing the internal structure of an electric toothbrush according to a first embodiment of the present invention.

[0036] Figure 3 A partially enlarged stereoscopic view of a force detection device of an electric toothbrush according to a first embodiment of the present invention is shown.

[0037] Figure 4 A partially enlarged stereoscopic view of a force detection device of an electric toothbrush according to a second embodiment of the present invention is shown.

[0038] Figure 5 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 is shown.

[0039] Figure 6 A perspective view showing the internal structure of an electric toothbrush according to a third embodiment of the present invention.

[0040] Figure 7 A three-dimensional view showing the internal structure of an electric toothbrush according to a third embodiment of the present invention from another perspective.

[0041] Figure 8 A perspective view showing the internal structure of an electric toothbrush according to a third embodiment of the present invention is shown, wherein the entire handle housing and components on the rear side of the force detection device are removed.

[0042] Fig. 9 A perspective view of an electric toothbrush according to a fourth embodiment of the present invention is shown.

[0043] Fig.10 A perspective view showing the internal structure of an electric toothbrush according to a fourth embodiment of the present invention.

[0044] Fig.11 A partially enlarged stereoscopic view showing the internal structure of an electric toothbrush according to a fourth embodiment of the present invention.

[0045] Fig.12 A perspective view of a force detection device of an electric toothbrush according to a fourth embodiment of the present invention is shown.

[0046] Fig.13 A perspective view of a force detection device of an electric toothbrush according to a fifth embodiment of the present invention is shown.

[0047] Fig.14 A stereoscopic view from another perspective of a force detection device of an electric toothbrush according to a fifth embodiment of the present invention is shown.

[0048] Fig.15 A perspective view of a force detection device of an electric toothbrush according to a sixth embodiment of the present invention is shown.

[0049] Fig.16 A perspective view showing a partial internal structure of an electric toothbrush according to a seventh embodiment of the present invention

[0050] Fig.17 A perspective view of a force detection device of an electric toothbrush according to a seventh embodiment of the present invention is shown.

[0051] Fig.18 and Fig.19 A circuit diagram according to a preferred embodiment of the present invention is shown.

[0052] Fig. 20 A circuit diagram of a second embodiment is shown.

[0053] Reference numerals:

[0054] 1, 201, 301 brush heads

[0055] 2. Handle device

[0056] 4,240 control circuit board

[0057] 5. Rotating assembly

[0058] 11,311 cleaning elements

[0059] 21, 221, 321 handle housing

[0060] 31,231 Rotating Pivot

[0061] 32, 232, 332, 632 drive shaft

[0062] 33. Interface parts

[0063] 34. Gear box cover

[0064] 35. Gearbox

[0065] 41, 241, 341, 441, 641 first inductor device

[0066] 42, 242, 342, 442, 642 second inductor device

[0067] 51, 151, 251 DC micro motor

[0068] 52, 152, 252 support parts

[0069] 53, Motor circuit board

[0070] 55, 155, 255, 355, 655 coil spring

[0071] 57,657 First Magnet

[0072] 58,658 Second Magnet

[0073] 150 permanent magnet

[0074] 250 Magnets

[0075] 310 permanent magnet

[0076] 311 Coil Assembly

[0077] 313, 413 first bearing

[0078] 314, 614 second bearing

[0079] 330, 430, 530, 630 leverage

[0080] 333 magnetic conductor

[0081] 336 lever pivot

[0082] 346, 347 Auxiliary magnetic conductor

[0083] 451, 551 inductor circuit board

[0084] 455 magnet isolation

[0085] L1', L2', inductors in the circuit

[0086] C, resonant capacitor

[0087] R, sampling resistor

[0088] Ui, input voltage

[0089] Uo, output voltage

[0090] I / O, MCU A / D sampling port

[0091] W1, F1>F2, the rotation direction of the first rotating component

[0092] W2, when F2>F1, the rotation direction of the first rotating component

[0093] W3 Center axis of drive shaft

[0094] W4 Longitudinal direction of cleaning element

[0095] W5 Pivot axis

[0096] W6, the direction of the reciprocating rotation of the second bearing 214 around W5 is shown

[0097] F1 is the external force applied to the bristles

[0098] F2, elastic force generated by the elastic element

[0099] F3, elastic force generated by the elastic element of the motor DETAILED DESCRIPTION

[0100] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated 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 protection scope of the present invention should not be limited by the content of this specific embodiment.

[0101] 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.

[0102] Figure 1 FIG. 2 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 micro motor 51. Figure 1 As shown, the electric toothbrush mainly includes a brush head 1 and a handle device 2. A cleaning element 11 such as bristles is provided on the brush head 1. The brush head 1 is mounted on a driving shaft extending toward the front side of the handle device 2 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, especially the part thereof provided with the cleaning element, becomes the force-bearing element of the electric toothbrush.

[0103] The handle device 2 of the electric toothbrush mainly includes a handle housing 21 and an internal movement. For an electric toothbrush driven by a DC micro motor 51, the internal movement mainly includes the DC micro motor 51, a gear box 35, a gear box cover 34, a drive shaft 32, an interface member 33 located on the gear box cover 34, a control circuit board 4, a motor circuit board 53 on which the DC micro motor 51 is installed, and a force detection device.

[0104] In the present invention, some parts of the internal movement of the electric toothbrush are fixedly connected together to form a rotating assembly, which can rotate relative to the handle housing. When the cleaning element 11 of the brush head 1 is subjected to force during use, the rotating assembly will rotate around the pivot 31, and the force detection device will be able to detect the external force applied to the cleaning element 11 as the rotating assembly moves. Usually, the external force to be detected is applied along the longitudinal direction of the cleaning element 11.

[0105] In the first embodiment, the rotating assembly 5 mainly includes a driving shaft 32 for installing a brush head in the internal movement, an interface member 33, a gear box cover 34, a gear box 35, a DC micro motor 51, a support member 52 and a motor circuit board 53, and these components are in a static state relative to each other after installation. The driving shaft 32 and the interface member 33 extend from the hole at the front end of the handle housing 1, and the other components in the rotating assembly are accommodated in the handle housing. A rotating pivot 31 is provided on the gear box cover 34, and the rotating pivot 31 is arranged in pairs, preferably extending from the gear box cover 34 in opposite directions as a whole. The rotating pivot 31 provides a rotating fulcrum for the rotating assembly 5, and the rotating assembly will rotate around the rotating pivot 31 after being subjected to force.

[0106] Combination Figure 7 Preferably, a rotating assembly bracket 61 is provided in the handle housing 21, and 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 a recess suitable for rotationally connecting with the rotating pivot 31, so that the rotating assembly 5 rotates relative to the rotating assembly bracket 61 when subjected to an external force, thereby also rotating relative to the handle housing 21. In other alternative embodiments, the handle housing can replace the rotating assembly bracket.

[0107] In order to return the rotating assembly to its initial position after the external force is removed, a resetting elastic element is provided between the rotating assembly 5 and the rotating assembly bracket 61. In a preferred embodiment, the elastic element is a coil spring 55, as shown in FIG. Figure 3 In the embodiment, the elastic element is constrained by the rotating component bracket 61 on the one hand, and is also constrained by the rotating component bracket 61 on the other hand. Specifically, one end of the coil spring 55 is attached to the contact end of the first rotating component bracket 61, and the other end of the coil spring 55 is attached to the support member 52 provided in the rotating component 5, so that the coil spring 55 provides an elastic movable connection between the rotating component bracket 61 and the rotating component 5, and the coil spring 55 can perform elastic telescopic movement along the axial direction 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 micro motor 51 and the control circuit board 4.

[0108] 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. Figure 3 As shown, 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 52 at a distance. The first inductor 41 and the second inductor 42 are welded on 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 substantially 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.

[0109] The inductor device in the present invention specifically refers to an inductive device including a fixed magnetic core and a conductor 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 a chip inductor widely used in the market; or it can be an inductor device composed of 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 inductor device can also be composed of a number of magnetic beads or silicon steel sheets. The inductor 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).

[0110] When the brush head 1 is guided by an external force to rotate the rotating assembly around the rotating pivot 31, the first magnet 57 and the second magnet 58 are close to the first inductor 41 and the second inductor 42. During this process, the magnetic flux generated by the first magnet 57 passing through the magnetic core of the first inductor 41 can make the magnetic core of the first inductor 41 enter a magnetic saturation state. Similarly, the magnetic flux generated by the second magnet 58 passing through the magnetic core of the second inductor 41 can make the magnetic core of the second inductor 41 enter a magnetic saturation state.

[0111] According to the physical definition of the self-inductance of the inductor, L1 = φ / I, where L1 is the self-inductance of the inductor, I is the current passing through the inductor, and φ is the magnetic flux generated by the inductor. When the magnetic core of the inductor enters the magnetic saturation state, the increase in the inductor coil current cannot bring about the corresponding magnetic flux generation, then the magnetic core of the inductor enters the magnetic saturation state, and the self-inductance drops rapidly, such as Figure 5 As shown in the curve, the accelerated change of self-inductance can more quickly and accurately respond to the applied external force.

[0112] In the first embodiment, the first magnet 57 and the second magnet 58 can be arranged such that when the first magnet 57 and the second magnet 58 are closest to the first inductor device 41 and the second inductor device 42, the fixed magnetic cores of the first inductor device 41 and the second inductor device 42 enter the magnetic saturation state, or the magnetic saturation state of the fixed magnetic cores is aggravated; when the first magnet 57 and the second magnet 58 are farthest from the first inductor device 41 and the second inductor device 42, the fixed magnetic cores of the first inductor device 41 and the second inductor device 42 exit the 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 Figure 2 shown), (F1 > F2), the first magnet 57 and the second magnet 58 are closest to the first inductor device 41 and the second inductor device 42 as the first rotating assembly 5 moves. The above-mentioned "farthest" means that under the combined action of the external force F1 and the elastic force f2, (F1 < F2), the first magnet 57 and the second magnet 58 are farthest from the first inductor device 41 and the second inductor device 42 as the first rotating assembly 5 moves. By adjusting the volume or size or surface remanence intensity of the first magnet 57 and the second magnet 58, and the distance between the first magnet 57 and the second magnet 58 relative to the magnetic cores of the first inductor device 41 and the second inductor device 42 and the magnetic cores, it is possible to achieve the entry and exit of the magnetic cores of the inductor devices 41 and 42 into and out of the magnetic saturation state, or the change in the degree of magnetic saturation of the magnetic cores within the displacement range of the first magnet 57 and the second magnet 58. The "magnetic saturation state of the magnetic core" mentioned here refers to that under the action of an external magnetic flux, the inductance of the detected inductor device starts to decrease from the inductance value of the inductance name, and the "nominal inductance value" refers to the inductance of the detected inductor device in a state without an external magnetic field and without current passing through the inductor device.

[0113] Referring to Figure 5 , point O represents that the fixed magnetic core of the inductor device is unsaturated, point A represents the initial saturation critical point of the magnetic core of the inductor device, the inductance values corresponding to both point O and point A are the nominal inductance values, the internal magnetic flux of the magnetic core corresponding to point A is Ф1, and the OA section represents that the fixed magnetic core of the inductor device is in the magnetic unsaturated state. The AB section represents that the magnetic core of the inductor device enters the preliminary saturation state. In Figure 5 the example, point B is set as the moderate saturation critical point of the fixed magnetic core, and is preferably set to have an inductance value of 70% of the nominal inductance value, and the internal magnetic flux of the fixed magnetic core corresponding to point B is Ф2. The BC section represents that the fixed magnetic core of the inductor device enters the moderate saturation state. In Figure 5In the example, point C is set as the critical point of deep saturation of the fixed magnetic core, preferably set to a corresponding inductance of 20% of the nominal inductance, and the magnetic flux inside the magnetic core corresponding to point C is Φ3. When the magnetic flux inside the magnetic core is Φ greater than Φ3, the magnetic core of the inductor device enters a deep saturation state, and the CD segment represents that the magnetic core of the inductor device enters a deep saturation state. In addition, point D is the full magnetic saturation point of the fixed magnetic core. At this point, the fixed magnetic core is in a full magnetic saturation state, and even if the external magnetic field increases, the magnetic flux of the fixed magnetic core no longer increases. It should be noted that the ratio of the nominal inductance represented by points B and C is only an example, and can be modified according to the characteristics of the selected inductor. In other alternative embodiments, the fixed magnetic core moderate saturation critical point B can be set to the magnetic state of the fixed magnetic core so that the corresponding inductance is 60%-80% of the nominal inductance; and the fixed magnetic core deep saturation critical point can be set to the magnetic state of the fixed magnetic core so that the corresponding inductance is within the range of 10%-30% of the nominal inductance. In general, the rate of change of the inductance of the inductor with the internal magnetic flux of the fixed magnetic core in the BC section is significantly greater than the corresponding rate of change in the AB section and the CD section. Preferably, the volume or size or surface residual magnetic strength of the first magnet 57 and the second magnet 58 and the distance between the first magnet 57 and the second magnet 58 and the fixed magnetic core of the first inductor 41 and the fixed magnetic core of the second inductor 42 are set so that when the magnets 57 and 58 are closest to their respective opposite inductors 41 and 42, the magnets 57 and 58 make the magnetic flux passing through the fixed magnetic core of the inductors 41 and 42 greater than Ф2 and less than Ф3. More preferably, the magnetic flux generated by the magnet during movement and passing through the magnetic core of the inductor is greater than Ф2 and less than Ф3. The fixed magnetic core entering the magnetic saturation state means that the magnetic state of the fixed magnetic core changes from being located at Figure 5 A point in the OA segment of the magnetic core moves along the curves of the OA segment and the AD segment, passing through point A, and moving toward point D. The magnetic core exiting the magnetic saturation state means that the magnetic state of the magnetic core changes from being located at Figure 5 A certain point in the AD segment moves along the curves of the DA segment and the AO segment, passing through point A, and moving toward point O. The intensification of the magnetic saturation state of the magnetic core means that the magnetic saturation state of the magnetic core changes from the point Figure 5 A certain point in the AD segment moves along the curve of the AD segment toward the direction of point D. The magnetic saturation state of the magnetic core is slowed down, which means that the magnetic saturation state of the magnetic core is from Figure 5 A point on segment AD moves toward point A along the curve of segment DA.

[0114] Fig.18 and Fig.19 The circuit arrangement diagram related to the first inductor device 41 and the second inductor device 42 is shown.

[0115] like Fig.19As shown, the first inductor 41 corresponds to the inductor L1 ’ , the second inductor 42 corresponds to the inductor L2 ’ , two inductors L1 ’ and L2 ’ They are connected in series with each other, and with the resonant capacitor C and the sampling resistor R. The two inductors L1 ’ and L2 ’ The total inductance and resonant capacitor C can form an LC resonant circuit or a resonant 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, so as to 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 inductor 41, 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 using an LED display or a sound reminder. Similarly, when the applied force F1 is within the appropriate range (e.g. 1.5N-2.5N), the MCU can output a signal of appropriate force, such as an LED display or a sound reminder. Similarly, when the applied force F1 is greater than the set value (e.g. 2.5N), the MCU can output a signal of excessive force, which can also be displayed by an LED or a sound reminder. Obviously, the sampled voltage can also come from Fig.19 U O1 , 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.

[0116] Fig.18 The detection circuit shown and Fig.19 The detection circuit shown is similar, the difference between the two is the LC resonant circuit, Fig.18 is an LC parallel resonant circuit, and Fig.19 For an LC series resonant circuit, Fig.18 The above-mentioned detection function can also be realized.

[0117] Figure 4 A second embodiment of the present invention is shown, 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 repeated here.

[0118] 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, and the permanent magnet 150 is preferably arranged in the hollow part of the coil spring 155, that is, the coil spring 155 surrounds the permanent magnet 150, but the permanent magnet 150 and the coil spring 155 can also be arranged separately. The permanent magnet 150 and the coil spring 155 are arranged together on a support member 152 fixed to the rear end of the motor 151.

[0119] The working principle of the force detection device of the second embodiment is the same as that of the first embodiment, which is to use the principle that after the magnetic core of the inductor 140 enters the magnetic saturation state by the magnet 150, the inductance will decrease faster, thereby more accurately detecting the external force applied to the brush head 1. Fig. 20 The circuit diagram of the second embodiment is shown, in which a single inductor L is connected in series with a resonant capacitor C and a sampling resistor R, which can also realize the above detection function.

[0120] 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 fixed magnetic core through the inductor device to enter and exit the magnetic saturation state, or in the case of Figure 5 In the AD section after the fixed magnetic core enters the magnetic saturation state, the magnetic saturation state of the fixed magnetic core of the inductor device is aggravated and the magnetic saturation state of the fixed magnetic core of the inductor device is relieved.

[0121] Figures 6 to 8 2 shows a third embodiment of the present invention. In the third embodiment, inside the handle housing 221, the force detection device disposed at the rear side of the motor 251 includes a magnetic conductor 250, wherein the magnetic conductor 250 is made of a material having a relative magnetic permeability of at least 10, such as a material having high magnetic permeability such as ferrite or silicon steel sheet. Figure 8 As shown, the magnetic conductor 250 is U-shaped, including two arms and a middle bridge portion, the two arms are respectively facing the fixed magnetic cores of the first inductor 241 and the second inductor 242, and there is a movement gap between the end faces of the arms and the fixed magnetic core. The magnetic conductor 250 is fixed to the support member 252 by glue, for example, through a dovetail groove provided on the middle bridge portion.

[0122] 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 surrounding the fixed magnetic core. The first inductor 241 and the second inductor 242 are fixed on a control circuit board 240 that is arranged 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 polarities of the respective remote magnetic poles generated by the current passing through the first inductor 241 and the second inductor 242 are opposite, for example, the remote magnetic pole of the first inductor 241 is an N pole, and the remote magnetic pole of the second inductor 242 is an S pole. In other alternative embodiments, the remote magnetic poles of the first inductor 241 and the second inductor 242 may also be of the same polarity.

[0123] In the third embodiment, the magnetizer 250 moves with the external force applied to the brush head 201 or the drive shaft 232, 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.

[0124] 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 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 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,

[0125]

[0126] 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 .

[0127] And as Fig.18 , Fig.19 As shown, the total inductance L of the inductive load in the detection circuit is expressed as follows:

[0128] L=L1+L2+2*M 12 .

[0129] 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 will be 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 will be affected. M12 can be a positive value or a negative value, and the positive or negative value depends on the direction of the external magnetic flux and the self-magnetic flux of the inductors 241 and 242, with the same direction being positive and the opposite direction being negative.

[0130] 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 FIG. Figure 2 The coil spring 255 on the support member 252 is in a state of being compressed or further compressed. The magnetic conductor 250 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, such as Fig.18 and Fig.19 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 ) rotates, the magnetic conductor 250 moves away from the far magnetic poles of the first inductor device 241 and the second inductor device 242 on the control circuit board 240, and the total inductance in the circuit becomes smaller.

[0131] Fig.18 and Fig.19 The specific application method of the circuit shown is the same as that described in the first embodiment, and will not be repeated here.

[0132] Figures 9 to 12 The fourth embodiment of the present invention is shown. Different from the above-mentioned embodiments, Fig.10As shown, the electric toothbrush includes a permanent magnet 310 and a coil assembly 311 located in a handle housing 321. The magnetic field lines of the permanent magnet 310 cut the current of the coil assembly 311, so that the resonant elastic element fixedly connected to the permanent magnet 310 and the mechanical assembly for realizing the resonant assembly (constituting a resonant assembly) make the permanent magnet 310 reciprocate around the axis of the drive shaft 332. The mechanical assembly in the resonant assembly includes a component 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 shape-fitting manner, and the drive shaft 332 will drive the cleaning element 311 to reciprocate around the centerline axis W3 of the drive shaft 313. In the electric toothbrush of the fourth embodiment, the drive shaft 332 or the brush head 301 can be regarded as a force-bearing element therein. Patent document CN104617732B discloses an electric toothbrush with a similar resonant assembly, and the relevant content of the patent document is cited here for reference.

[0133] like Fig.11 As shown, the electric toothbrush further comprises a first bearing 313 and a second bearing 314 spaced apart along the direction of the central axis W3 of the drive shaft 332, and the first bearing 313 is closer to the force-bearing element than the second bearing 314. The drive shaft 332 is fastened together with the two bearings 313 and 314, thereby constituting a rotating assembly of the electric toothbrush, which rotates around a pivot axis W5 passing through the first bearing 313 near the brush head. The first bearing 313 has inner and outer rings and balls arranged on the inner and outer rings, the outer ring is arranged stationary relative to the handle housing, and 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 element 311 on the brush head, the first bearing 313 provides a pivot axis for the rotating assembly, that is, the pivot axis W5 passes through the first bearing 313, and in some specific embodiments, the pivot axis W5 passes through the balls arranged radially opposite to each other in 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 element 311 on the brush head and perpendicular to the central axis W3 of the drive shaft 332 .

[0134] like Fig.10 As shown, the first bearing 313 is fixedly mounted to the transducer left shell 316 and the transducer right shell 317. The transducer left shell 316 and the transducer right shell 317 are installed inside the handle shell to be stationary relative to the handle shell. That is, the outer ring of the first bearing 313 is stationary relative to the handle shell, while the second bearing 314 is movable relative to the transducer left and right shells or the handle shell. The rotational movement of the second bearing 314 is Fig.12The force detection device in the first, second and third embodiments can be arranged near the second bearing 314, and the displacement between two relatively movable elements (such as a magnet and an inductor or a magnetic conductor and an inductor) in the force detection device is generated as the rotating assembly rotates around the axis W5, thereby indicating whether the force on the force-bearing element exceeds the threshold.

[0135] In this type of electric toothbrush, the length of the force arm on the side of the pivot axis W5 away from the force-bearing element in the rotating assembly is shorter than that in the first embodiment. Generally, the force arm formed between the first bearing 313 and the second bearing 314 relative to the axis W5 is smaller than the force 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 of the relative moving element. To solve this problem, a lever assembly is provided in the electric toothbrush of the fourth embodiment to amplify the displacement of the force detection device relative to the moving element.

[0136] Specifically, if Fig.11 As shown, the lever assembly includes a lever 330, on which a lever pivot 336 providing a lever rotation axis is arranged, and the lever pivot 336 is, for example, mounted to a housing of a transducer stationary relative to the handle housing 321 or directly connected to the handle housing 321. The lever 330 includes a short arm and a long arm, wherein the short arm contacts the second bearing 314, and the long arm is connected to the first bearing 313 through a coil spring 355. In this way, when an external force F1 is applied to the force-bearing element, the rotating assembly rotates around a pivot axis W5, which passes through the first bearing 313 and is substantially parallel to the pivot axis of the lever pivot 336, and the elastic element fixedly connected to the permanent magnet 310 generates an elastic resistance force F3, and the coil spring 355 generates an elastic force F2. The elastic force F2 transmits the resistance force to the second bearing 314 through 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.

[0137] Specifically, Fig.11 , Fig.12 As shown, the force detection device includes a relatively movable magnet 333 and a pair of inductors 341 and 342, wherein the magnet 333 is fixed on the long arm of the lever 330, that is, the magnet 333 is movably installed relative to the handle housing, and the inductors 341 and 342 are statically installed relative to the handle housing, for example, installed on an inductor circuit board at a static position relative to the handle housing. Preferably, the inductor circuit board is fixed to the housing of the transducer. Fig.12As shown, the movement direction of the magnetic conductor 333 is approximately parallel to the direction of the magnetic force lines inside 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.

[0138] Preferably, in order to enhance the effect 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 are basically facing 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.

[0139] Fig.13 and Fig.14 The schematic diagram of the force detection device in the fifth embodiment of the present invention is shown. Different from the fourth embodiment, the first and second inductors 441, 442 are welded on the inductor circuit board 451 located on the side of the lever 430. The inductor circuit board 451 on the side is arranged substantially perpendicular to the direction of 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 by wires. The polarities of the far magnetic poles of the two inductors 441, 442 are opposite. A magnetic isolation body 455 is installed on the long arm of the lever 430. When the magnetic isolation body 455 moves with the lever 430 and is inserted into the space between the first and second inductors 441, 442, it will block the external magnetic flux between the two inductors 441, 442, and can change the mutual inductance of multiple inductors, thereby providing a measurement result of the feedback external force size. Here, the magnetic isolation body 455 refers to a material with a relative magnetic permeability less than 1. For example, the magnetic isolation body 455 can preferably be copper metal.

[0140] Fig.15 The schematic diagram of the force detection device in the sixth embodiment of the present invention is shown. The first and second inductors 541 and 542 are arranged on the side of the lever 530 by using an independent inductor PCB board 551, and the mutual inductance between the two inductors 541 and 542 is affected by using a magnetic conductor similar to the first embodiment.

[0141] In the above embodiment using mutual inductance, the first inductance device and the second inductance device are used for illustration. In fact, there may be more than two inductance devices, and the mutual inductance between the multiple inductance devices will also be affected by the mutual inductance device moving in the external magnetic flux of the multiple inductance devices and change. No further details will be given here.

[0142] Fig.16 and Fig.17 The schematic diagram of the force detection device in the sixth embodiment of the present invention is shown. In the fourth and fifth embodiments, the lever 530 extends from the second bearing toward the front side of the electric toothbrush. Unlike these embodiments, 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, in the direction away from the drive shaft 632, while the short arm of the lever 630 is still 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 installed at the far end of the long arm of the lever 630, opposite to the first and second inductance devices 641 and 642 on the back of the fixed circuit board. A coil spring 655 for resetting the rotating assembly is also provided on the long arm. These magnets can also be replaced by energized coils. Similar to the effect of the magnet on the inductor in the first embodiment, the magnetic pole of the magnet faces the direction of the internal magnetic force lines of the inductor, and at least when the magnets 657 and 658 are closest to the detection position of the inductor 641 and 642, the magnetic flux generated by the magnets 657 and 658 passing through the magnetic cores of the inductor 641 and 642 causes the fixed magnetic core of the inductor to enter a magnetic saturation state. In this embodiment, the magnet can also be replaced by an energized coil.

[0143] In the above embodiments, the rotating assembly has a first bearing and a second bearing, wherein the first bearing close to the drive shaft provides a pivot axis, which is exemplary, and in other alternative embodiments, the rotating assembly pivot assembly may also pass through the second bearing away from the drive shaft, that is, the second bearing is fixedly mounted relative to the handle housing, and the first bearing is movably mounted relative to the handle housing. In addition, in some other alternative embodiments, there may be only one bearing.

[0144] 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 for other purposes with force control requirements, such as facial cleansing and massage, and the brush head can also be transformed into other similar processing heads, such as a massage head.

[0145] Although the present invention is disclosed as above with preferred embodiments, it 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 modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope 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, which includes a pivot portion and a lever, the lever having a long arm and a short arm, the short arm of the lever being attached to an end of the rotating assembly opposite to the force-bearing element, and the first element being mounted 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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