The present disclosure relates to the field of clean-and-care appliances, and more specifically, to a transducer device and a pressure alarm mechanism in a clean-and-care appliance.
It is important for a personal clean-and-care appliance, such as an electric toothbrush, an electric shaver, an electric facial cleaner and an electric shower, to have a transducer device that can convert a reciprocating motion into a desired rotational motion of a cleaning element. Such personal clean-and-care appliances need to have a simple structure, easy assembly, long service life, safety and reliability, and small size.
It is known that there are many driving structures, such as motors, magnetic systems and electromagnetic systems, for driving the cleaning element. Some of the driving structures use bearings such as a ball bearing to support a driver. Such a structure is expensive and complex, and also has noise and motor damping.
The applicant has another Chinese disclosure patent with the Publication No. CN 104617732 B, which discloses a personal clean-and-care appliance. A transducer of the personal clean-and-care appliance includes a driving shaft, transducer elastic member fixing members fastened to left and right supports of a driver, at least two permanent magnets, corresponding permanent magnet supports fixedly coupled to the permanent magnets, left and right transducer transmission arms that are fixedly coupled to the permanent magnet supports and the driving shaft, and at least a left transducer elastic member and a right transducer elastic member that are disposed on left and right sides of a longitudinal axis of the driving shaft, where the left and right permanent magnets are separate from each other, the permanent magnet on one side has a magnetic polarity of either S pole or N pole in the direction of a driving coil, the permanent magnet on the other side has a magnetic polarity, opposite to the magnetic polarity of the permanent magnet on the one side, in the direction of the driving coil, the left and right permanent magnets are disposed and angles between directions of their internal magnetic lines and a direction of a longitudinal axis of the driving coil are each greater than 45° and less than 135°, and the left and right permanent magnets can move relative to the elastic member fixing members and when an alternating current I with a frequency of f0 passes through the driving coil, movement directions of the left and right permanent magnets are approximately parallel to a direction of a longitudinal axis of an iron core of the driving coil.
In the above solution, the driving shaft does not need to be equipped with a ball bearing. However, due to a limited capability of the elastic members to balance pressure on the cleaning element, long-time use of the elastic members is likely to cause fatigue and therefore yielding of the elastic members, consequently affecting the service life of the transducer. In one embodiment, since the elastic members are respectively fixedly coupled to corresponding transducer transmission arms and transducer elastic member fixing members, the overall size of the transducer is large, which is not conducive to miniaturization of the cleaning appliance. Therefore, the existing personal clean-and-care appliance still needs to be improved.
To overcome the deficiencies in the prior art, the present disclosure provides a transducer device for a personal clean-and-care appliance, the transducer device including: a transducer and driving coils, where the transducer includes a transducer frame, magnets attached to the transducer frame, an elastic assembly attached to the transducer frame, and a driving shaft, where the driving shaft has a proximal end and a distal end, the driving shaft is fixedly attached to the transducer frame, and the driving shaft defines a longitudinal axis which extends through a median plane, and the median plane is substantially perpendicular to a cleaning action force on the clean-and-care appliance; and the driving coils are arranged opposite to the magnets of the transducer, and the transducer is movable relative to the driving coils, where the elastic assembly includes at least one proximal elastic member and at least one distal elastic member which are arranged offset along the longitudinal axis, and the proximal elastic member is closer to the proximal end of the driving shaft than the distal elastic member, where the proximal elastic member and the distal elastic member each have a first edge and a second edge, the first edges are fixedly coupled to the driving shaft to move with the driving shaft, the second edges form fixed edges when the proximal elastic member and the distal elastic member are elastically deformed, and respective planes of the proximal elastic member and the distal elastic member substantially extend radially outward from the longitudinal axis.
According to some embodiments of the present disclosure, a distance between center lines of the respective widths of the proximal elastic member and the distal elastic member along the longitudinal axis is at least 3.5 mm.
According to some embodiments of the present disclosure, the plane of the proximal elastic member forms a first angle relative to the median plane, and the plane of the distal elastic member forms a second angle relative to the median plane, where the first angle and the second angle are greater than or equal to 10 degrees and less than or equal to 90 degrees.
According to some embodiments of the present disclosure, the proximal elastic member and the distal elastic member are located on two opposite sides of the median plane or on the same side of the median plane, and the proximal elastic member and the distal elastic member are located on two opposite sides or the same side of a perpendicular plane that is perpendicular to the median plane P and includes the longitudinal axis. Alternatively, the proximal elastic member and the distal elastic member are disposed along a direction of the perpendicular plane.
According to some embodiments of the present disclosure, the proximal elastic member is made of plastic or metal, and the distal elastic member is made of plastic.
According to some embodiments of the present disclosure, proximal elastic members are arranged in a pair symmetrically about the longitudinal axis, and distal elastic members are arranged in a pair symmetrically about the longitudinal axis.
According to some embodiments of the present disclosure, the elastic assembly further includes at least another elastic member made of metal, the elastic member is arranged offset relative to the proximal elastic member and the distal elastic member along the longitudinal axis, and an angle between a plane of the metal elastic member and the median plane is less than the angles between the median plane and the planes of the proximal elastic member and the distal elastic member. A total elastic modulus of the another metal elastic member is twenty or more times greater than a total elastic modulus of the distal elastic member.
According to some embodiments of the present disclosure, the transducer frame includes a transducer frame portion enclosing the driving shaft and frame fastening arms that are paired and spaced radially from the driving shaft, where the frame fastening arms each have an upper protrusion and a lower protrusion, the upper protrusion and the lower protrusion are arranged offset from each other on the frame fastening arm, the first edges are fixed to the transducer frame portion, and the second edges are respectively fixed to the upper protrusion and the lower protrusion of the frame fastening arm.
The present disclosure further provides a pressure alarm mechanism for a clean-and-care appliance, the pressure alarm mechanism including: a driving shaft defining a longitudinal axis and having a proximal end and a distal end, a driving portion being attached to the driving shaft from the distal end of the driving shaft, and the proximal end generating a first displacement in a first direction when a cleaning action force F1 of the clean-and-care appliance is in the first direction; a proximal elastic member, a first edge of the proximal elastic member being fixedly coupled to the driving shaft to move with the driving shaft, and a supporting point for the driving shaft being formed at the position of the proximal elastic member; a distal elastic member, disposed offset toward the distal end along the longitudinal axis relative to the proximal elastic member, a first edge of the distal elastic member being fixedly coupled to the driving shaft to move with the driving shaft, and the driving shaft at the position of the first edge of the lower elastic member generating a second displacement in a second direction opposite to the first direction when the cleaning action force F1 is applied to the proximal end; and a sensing device, including a fixed component and a movable component, where the movable device is disposed on the driving portion, and when the cleaning action force F1 is applied to the proximal end, the movable component generates a third displacement in the second direction relative to the fixed component, and when the cleaning action force F1 exceeds a maximum force F1M, the displacement of the movable component relative to the fixed component causes an alarm device of the pressure alarm mechanism to generate an alarm indication.
According to some embodiments of the present disclosure, the proximal elastic member and the distal elastic member each have a second edge opposite to the first edge, and the second edges form fixed edges when the proximal elastic member and the distal elastic member are elastically deformed, where a distance between center lines of the respective widths of the proximal elastic member and the distal elastic member along the longitudinal axis is at least 3.5 mm. A plane of the proximal elastic member forms a first angle relative to the median plane (P), and a plane of the distal elastic member forms a second angle relative to the median plane, where the first angle and the second angle are greater than or equal to 10 degrees and less than or equal to 90 degrees.
According to some embodiments of the present disclosure, the longitudinal axis extends through a median plane, the median plane is substantially perpendicular to the cleaning action force, a plane of the proximal elastic member forms a first angle relative to the median plane P, and a plane of the distal elastic member forms a second angle relative to the median plane, where the first angle and the second angle are greater than or equal to 10 degrees and less than or equal to 90 degrees, where the proximal elastic member and the distal elastic member are located on two opposite sides of the median plane or on the same side of the median plane, and the proximal elastic member and the distal elastic member are located on two opposite sides of a plane where a direction of the cleaning action force and the longitudinal axis are located or along the direction of the cleaning action force.
According to some embodiments of the present disclosure, the driving portion includes magnets and a frame, the magnets are attached to the distal end of the driving shaft via the frame, and the movable component is farther away from the proximal elastic member than the proximal end of the driving shaft.
According to some embodiments of the present disclosure, the fixed component of the sensing device includes a sensing apparatus and an emission source, a gap is formed between the sensing apparatus and the emission source, and the movable component includes a stop that can move into the gap between the sensing apparatus and the emission source, where the sensing apparatus and the emission source include at least one of an electrical, magnetic, and optical sensing apparatus and an emission source.
According to some embodiments of the present disclosure, the sensing apparatus and the emission source are disposed on a circuit board or a housing of the clean-and-care appliance or on a part fixed relative to the housing. The part fixed relative to the housing includes a circuit board, a battery compartment frame, and the like.
According to some embodiments of the present disclosure, the pressure alarm mechanism includes a force limiting portion, which limits a movement range of the movable component, and the maximum force F1M of the sensing apparatus ranges from 2.5 N to 15 N, where a maximum force limiting portion is disposed on the housing of the clean-and-care appliance or the part fixed relative to the housing.
In addition, the present disclosure further provides a clean-and-care appliance, which includes the transducer device as described above or the pressure alarm mechanism as described above. The clean-and-care appliance includes one of an electric toothbrush, an electric shaver, an electric facial cleaner, and an electric shower.
Furthermore, according to the present disclosure, the driving coils are arranged to have no relative movement relative to the housing of the clean-and-care appliance, the driving coils are arranged in a magnetic field generated by the magnets, an angle between the magnetic lines generated by the magnets and the directions of currents I in the driving coils is approximately 90 degrees, the alternating currents I with a frequency of f0 passes through the driving coils, and the driving coils interact with the magnets to generate a reciprocating force couple with the longitudinal axis of the driving shaft as an axis, and the reciprocating force couple drives the transducer to perform harmonic vibration.
In addition, in the clean-and-care appliance according to the present disclosure, the transducer and a cleaning assembly of the clean-and-care appliance form a harmonic vibration body, the driving coils and the magnets interact to generate a reciprocating force couple with the longitudinal axis L2 of the driving shaft as an axis, the reciprocating force couple drives the harmonic vibration body to perform harmonic vibration, and a natural frequency fn of the harmonic vibration body is between 85% and 115% of the frequency f0 of the reciprocating force couple.
The use of the transducer device according to the present disclosure solves the problem of the elastic members being prone to fatigue and thus yield, improves the service life of the transducer device, realizes miniaturization of personal clean-and-care appliances, and also achieves easy assembly, smooth rotation, low noise, low damping, safety and reliability. In addition, it is beneficial for the pressure alarm mechanism to be able to identify an amount of force applied on the cleaning element.
For a more complete understanding of the present disclosure, the following description of exemplary embodiments may be considered with reference to the accompanying drawings.
The present disclosure will be further described below in conjunction with particular embodiments and the accompanying drawings, and more details are explained in the following description for the ease of fully understanding the present disclosure; however, the present disclosure can be implemented in various different manners than that described herein, a person skilled in the art can make an similar extension and deduction without departing from the connotation of the present disclosure according to the practical applications, and therefore the scope of protection of the present disclosure should not be limited to the content of the particular embodiments herein.
Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings using a typical example in which an electric toothbrush is used as a personal clean-and-care appliance. Although the electric toothbrush is merely used as an example for explanation below, the present disclosure is not limited thereto. The present disclosure is also applicable to an electric shaver, an electric facial cleaner, an electric shower and other clean-and-care appliances that can provide cleaning actions by means of a transducer.
For the sake of clarity, words describing spatial relative positions such as “upper”, “lower”, “left”, “right”, “proximal end” and “distal end” are used in this specification to briefly describe a relationship between one element or feature shown in the figures and another element(s) or feature(s), where a direction of a longitudinal axis of a driving coil refers to a direction of a magnetic line generated inside an iron core when a current I flows through the driving coil in a direction parallel to it. “Upper” and “lower” are discussed with respect to the longitudinal axis of the driving shaft, when facing a corresponding view, an upward direction parallel to the longitudinal axis of the driving shaft is defined as “upper”, and a downward direction parallel to the longitudinal axis of the driving shaft is defined as “lower”. “Left” and “right” are discussed with respect to the longitudinal axis of the driving shaft, when facing a corresponding view, in a direction perpendicular to the longitudinal axis of the driving shaft, a left side of the longitudinal axis of the driving shaft is defined as “left”, and a right side of the longitudinal axis is defined as “right”. “Proximal/proximal side” refers to an end or side close to a position where a cleaning action force is applied during use of the clean-and-care appliance. “Distal/distal side” refers to an end or side away from a position where the cleaning action force is applied during use of the clean-and-care appliance.
In addition, the word “and/or” used in the present application includes any and all combinations of one or more words of the listed associated words.
Although the word “first” and the like are used in this specification to describe elements or components, these elements or components should not be limited by these words. These words are merely used to distinguish one element or component from another element or component and do not include a “sequence”. Therefore, interchange of ordinal numbers of the elements or components discussed below does not exceed the concept and scope of the present disclosure.
The functional components in the handle 1 of the clean-and-care appliance mainly include a power supply portion, a control portion, a trigger portion, and a transducer device. Generally, the power supply portion includes a rechargeable battery 5 mounted in a battery compartment 135 and a charging circuit, to provide power to various portions of the appliance. The control component mainly includes a circuit board 4 for controlling various working modes of the electric toothbrush and on or off of the electric toothbrush. The trigger portion includes a switch for starting and stopping the operation of the electric toothbrush. The transducer device is configured to convert input electrical energy into mechanical energy that provides reciprocating motion of the cleaning assembly.
In one embodiment, the transducer frame 110 is made of plastic. In the first embodiment, the first magnet 102 and the second magnet 103 as part of the transducer 7 are fixedly coupled, by means of glue, screws or injection molding, to a distal end of the transducer frame 110 away from the cleaning element 3, and the magnets 102, 103 become an integral part of the transducer 7.
In one embodiment, the transducer device further includes an upper transducer housing 131 and a lower transducer housing 132, which are fastened together via, for example, fastening screws 133, to press frame fastening arms 113 of the transducer frame 110 between the two housings and locking the transducer frame 110 accordingly. The upper transducer housing 131 and the lower transducer housing 132 are further fastened to a housing of the appliance. However, it should be understood that in other alternative embodiments, the upper and lower transducer housings may also be an integral part of the handle housing.
In one embodiment, as shown in
Each of the first elastic members 104A and 104B is substantially a cuboid. A distance of each of the first elastic members 104A and 104B from the frame fastening arm 113 to the transducer frame portion 112 is the length of the elastic member, a distance of each of the first elastic members 104A and 104B along a direction of the longitudinal axis L2 of the driving shaft is called the width of the elastic member, the length of the remaining dimension of the cuboid is the thickness of the elastic member, and a plane formed by the length and the width of each of the first elastic members 104A and 104B is an elastic member plane. Similarly, each of the second elastic members 105 is substantially a cuboid, a distance of each of the second elastic members 105A and 105B from a frame protrusion 111 of the frame fastening arm 113 to the transducer frame portion 112 is the length of the elastic member, a distance of each of the second elastic members 105A and 105B along the direction of the longitudinal axis of the driving shaft is the width of the elastic member, and the length of the remaining dimension of the cuboid is the thickness of the elastic member. A plane formed by the length and the width of each of the second elastic members 105A and 105B is an elastic member plane.
As shown in
Further, the second elastic members 105 of the elastic assembly include proximal elastic members 105A and distal elastic members 105B arranged in pairs, and the two pairs of elastic members are arranged offset along the longitudinal axis L2. The proximal elastic members 105A are closer to the proximal end of the driving shaft 101, while the distal elastic members 105B are closer to the distal end of the driving shaft 101. The plane of each second elastic member 105 is a plane that connects the respective frame protrusion 111 and the transducer frame portion 112 enclosing the driving shaft, and In one embodiment, an angle between the plane and the median plane where the longitudinal axis L2 is located is greater than 30 degrees, and In one embodiment, an angle between the plane and the longitudinal axis L2 is less than 30 degrees.
Different from the arrangement of the first elastic members 104A and 104B in the median plane P, the four second elastic members 105 are arranged at an angle relative to the median plane P, that is, the four second elastic members 105 are arranged at an angle relative to the longitudinal axis L1 of the cleaning element 3 and the plane where the longitudinal axis L2 is located. The proximal elastic members 105A and the distal elastic members 105B are respectively obliquely arranged on two opposite sides of the median plane P, as shown in
As shown in
In the first embodiment, the first elastic members 104 and the second elastic members 105 are all fixed by means of the transducer frame 110. In one embodiment, as shown in
Edges 106 of the first elastic members 104 in a pair are respectively fixedly coupled to the two frame fastening arms 113, and the other edges 107 of the first elastic members 104 are fixedly coupled to the transducer frame portion 112 enclosing the driving shaft, and substantially correspond to the position of the longitudinal axis L2, the first elastic members 104A and 104B extend between the frame fastening arms 113 and the transducer frame portion 112 near the longitudinal axis L2.
Similarly, an edge 109 of each of the second elastic members 105A and 105B is fixedly coupled to the transducer frame portion 112 enclosing the driving shaft, while an opposite edge 108 is fixedly coupled to the frame fastening arm 113. In order to realize the arrangement of the second elastic members 105A and 105B at an angle relative to the median plane P, the frame protrusions 111 protrude from two opposite sides of the frame fastening arm 113. The frame protrusions 111 are part of the frame fastening arm 113. Therefore, the frame protrusions 111 may also be understood as part of the transducer frame 110. The edge 108 of each of the second elastic members 105 is fixed to a corresponding frame protrusion 111.
In other alternative embodiments, it is also possible that no frame protrusion 111 is provided. For example, the frame protrusions 111 may be replaced by thickening the frame fastening arm 113.
The two first elastic members 104A and the two first elastic members 104B that are distributed in a staggered manner along the longitudinal axis L2 of the driving shaft are all made of metal. As shown in
In one embodiment, it may be considered that the proximal elastic members may include two separate second elastic members 105A, while the distal elastic members may include two separate second elastic members 105B. As shown in
As shown in
A movement analysis is performed below based on the transducer device according to the first embodiment of the present disclosure.
Referring to
In the first embodiment, the elastic members 104A and 104B are made of metal or mainly made of metal, the second elastic members 105A may be made of plastic or metal, and the second elastic members 105B are made of plastic or mainly made of plastic. In the present disclosure, for convenience of description, it is usually noted that the elastic member is made of metal or plastic, but it should be understood that the elastic member may be a composite of metal and plastic. When 60% or more of the stiffness coefficient of the elastic member comes from metal, it is said that the elastic member is mainly made of metal. When 60% or more of the stiffness coefficient of the elastic member comes from plastic, it is said that the elastic member is mainly made of plastic. When neither of the stiffness coefficient contributions of metal and plastic is greater than 60% of the stiffness coefficient of the elastic member, the elastic member is a composite of metal and plastic.
When the second elastic members 105 are made of plastic or mainly made of plastic, as shown in
An analysis is performed below taking an example in which the material of the elastic members 105A and 105B is plastic.
According to the principle of solid mechanics, in a bending elastic deformation state, the elastic members are equivalent to linear springs. Taking a cuboid elastic member as an example, the stiffness coefficient of a linear spring equivalent to the elastic member is:
In one embodiment, the elastic modulus E1 of the material of the first elastic members 104A and 104B is 20 times greater than the elastic modulus E2 of the material of the second elastic members 105A and 105B. For example, the material of the first elastic members 104A and 104B is stainless steel, the elastic modulus E1 is 196 GPa, the material of the second elastic members 105A and 105B is POM, and the elastic modulus E2 is 2.5 GPa. An inertia moment of the first elastic members 104A and 104B relative to the electromagnetic torque M1 is a first elastic member inertia moment IZ1, and an inertia moment of the second elastic members 105A and 105B relative to the electromagnetic torque M1 is a second elastic member inertia moment IZ2. According to solid mechanics, an inertia moment of a cuboid is:
When a driving frequency f0 is equal to the mechanical natural frequency fn, the mechanical portion is in forced resonant motion. When the alternating current I with the frequency of f0 passes through the driving coils, the transducer 7 and the cleaning assembly are subjected to electromagnetic forces with the frequency of f0, and the frequency f0 of the driving force is between 85% and 115% of the natural frequency fn of the transducer 7. According to the principle of simple harmonic vibration, generally, when the frequency f0 of the driving force is between 85% and 115% of the mechanical natural frequency fn, it may be considered that the mechanical portion is in forced harmonic motion, and the electrical energy of harmonic motion and resonant motion is converted into mechanical energy with a high efficiency. During the harmonic motion of the transducer 7 and the cleaning assembly, the elastic members will consume part of energy due to an internal force of the material, which is equivalent to the energy consumed by the internal resistance of the material, this part of energy is manifested in the heating phenomenon of the material of the elastic members, and the smaller the elastic modulus of the material, the greater the internal resistance, and the higher the temperature rise of the material. Therefore, the first elastic members 104A and 104B are mainly made of metal and have a higher elastic modulus, while the second elastic members 105A and 105B are mainly made of plastic, the second elastic members 105A and 105B have a smaller elastic modulus, and the heat dissipation effect of the metal material is much better than the heat dissipation effect of the plastic material. In the harmonic motion of the transducer 7 and the cleaning assembly, the temperature rise of the first elastic members 104A and 104B is much lower than the temperature rise of the second elastic members 105A and 105B. The temperature rise will cause the elastic modulus of the material of the elastic members to decrease, to make the stiffness coefficients of the elastic members smaller. In an embodiment where the second elastic members 105A and 105B are made of plastic, the temperature rise of the first elastic members 104A and 104B has a limited impact on the stiffness coefficients of the first elastic members, and thus can be ignored. The temperature rise of the second elastic members 105A and 105B has a greater impact on the stiffness coefficients of the second elastic members. In order to keep the transducer 7 and the cleaning assembly in a harmonic motion state throughout a working period, according to the above formulas and principle analysis, assuming that the stiffness coefficients of the second elastic members 105A and 105B decrease to zero due to the temperature rise, when (K1t+K2t)2/(K1t) 2<1.15/0.85, and when K1t>6.13K2t, the transducer 7 and the cleaning assembly are in the harmonic motion state throughout the working period. The spring stiffness coefficient in the natural frequency of the transducer 7 and the cleaning assembly mainly depends on the stiffness coefficients of the first elastic members 104A and 104B. In the first embodiment, the sum of all the first elastic member stiffness coefficients is 6.13 times greater than the sum of all the second elastic member stiffness coefficients, to ensure that the transducer is in an efficient harmonic vibration state throughout the working period.
In other alternative embodiments, the proximal elastic members 105A may be made of metal or mainly made of metal, the distal elastic members 105B may be made of plastic or mainly made of plastic, and the sum of the stiffness coefficients of all the first elastic members and the sum of the stiffness coefficients of all the proximal second elastic members is 6.13 times greater than the sum of the stiffness coefficients of all the second lower elastic members. In this case, the material of the first elastic members 104A and 104B is metal, the material of the second elastic members 105B is plastic, and the elastic modulus of the first elastic members 104A and 104B is 20 or more times greater than the elastic modulus of the second elastic members 105B. The angles between the first elastic member planes and the longitudinal axis of the cleaning element are the angle β. The angles between the second elastic member planes and the longitudinal axis of the cleaning element are the angle α, and the angle β is greater than the angle α.
The inventors have found that a distance between the equivalent force F2 on the second elastic members 105A and the equivalent force F3 on the second elastic members 105B is particularly important for the force moment balance. Through a large number of experiments and based on the feasibility of the production process, along the direction of the longitudinal axis L2 of the driving shaft, a distance between a center line L3 of the second elastic member 105A and a center line L4 of at least one second elastic member 105B is 3.5 mm or more, and the center line refers to a second elastic member plane center line that is located on the plane of the second elastic member 105A or 105B and points from the respective frame protrusion 111 to the transducer frame portion 112 enclosing the driving shaft, or it may be understood that, the center line refers to a second elastic member plane center line that is located on the plane of the second elastic member 105A or 105B and points from the transducer frame 110 to the transducer frame portion 112 enclosing the driving shaft. Since the distance between the center line L3 of at least one proximal second elastic member and the center line L4 of at least one distal second elastic member is 3.5 mm or more, it is more possible to avoid torsional deformation of the second elastic member 105 caused by the force F1 on the cleaning element 3 compared to the case where only one second elastic member 105A is provided, to avoid an excessive stress of the second elastic member, to avoid a failure of the transducer 7.
Continuing to refer to
In other alternative embodiments, the second elastic members 105A and 105B may be rotated 180 degrees about the longitudinal axis L2 of the driving shaft, then Y2 becomes a distance by which the material of the second elastic members 105B is compressed, and therefore Y2 is the distance by which the material of the second elastic members 105B is stretched or compressed.
In one embodiment, the driving shaft based on the proximal elastic members 105A, the distal elastic members 105B, and the transducer frame can constitute a pressure alarm mechanism for the electric toothbrush, which is configured to send an alarm when the cleaning action force applied on a brush head exceeds a predetermined value. The pressure alarm mechanism includes a sensing device. The sensing device includes at least one movable component disposed on the magnet at the distal end of the driving shaft or on the transducer frame, in one embodiment, disposed at the distal end of the magnet or at the distal end of the transducer frame along the longitudinal axis L2. When the cleaning action force F1 is applied to the proximal end, the movable component generates a third displacement Y3 in the second direction, and when the cleaning action force F1 exceeds the maximum force F1M, the displacement of the movable component causes an alarm device of the pressure alarm mechanism to generate an alarm indication.
Referring to the example of
In the first embodiment, as shown in
In the embodiments according to the present disclosure, the displacement Y3 is effectively amplified due to the lower second elastic members 105B that are made of plastic or mainly made of plastic, that is, a displacement opposite to the direction of the force F1 on the cleaning element that is generated under the action of the force F1 on the cleaning element by part of the transducer frame 110 farther away from the cleaning element 3 than the second elastic members 105A and the magnets is effectively amplified.
The embodiment of the alarm mechanism may be appropriately modified, for example, a through hole may be provided in the frame follower 114. When the force F1 on the cleaning element is zero, light from the light source 402 does not pass through or a small amount of the light passes through the through hole of the frame follower 114 and is incident on a photosensitive surface of the photosensitive apparatus 401, and the rest of the frame follower 114 blocks the light from the light source 402 from being incident on the photosensitive surface of the photosensitive apparatus 401. At this time, the equivalent resistance of the photosensitive apparatus 401 is relatively large. When the force F1 on the cleaning element increases, more light of the LED 402 passes through the through hole of the frame follower 114 and is incident on the photosensitive surface of the photosensitive apparatus 401. At this time, the equivalent resistance of the photosensitive apparatus 401 decreases, to implement detection of the circuit board 4 on the amount of the force F1 on the cleaning element.
In the above embodiment, the frame follower 114 has a convex shape relative to the surfaces of the magnets. In one embodiment, the frame follower 114 may be in a concave shape, a flat shape, or a curved surface shape, and a displacement Y3 of one of the surfaces may be used to make at least one surface of the follower 114 close to or away from the photosensitive apparatus 401, and an incident angle at which the photosensitive apparatus 401 can receive the light from the light source 402 changes, to make a luminous flux on the photosensitive apparatus 401 change monotonically with the monotonic change of the force F1 on the cleaning element.
The magnets may also be used as a movable component of the sensing device, the displacement Y3 of the magnets away from the cleaning element may be used, a magnetic field induction apparatus such as a Hall element or a coil is mounted on the circuit board 4, and the displacement Y3 of the magnets results in a change in a magnetic field intensity on the magnetic field induction apparatus, to cause a change in a voltage value of the magnetic field induction apparatus, thus enabling the circuit board 4 to detect the amount of the force F1 on the cleaning element.
In one embodiment, the transducer device is set to have a start-up force F4. In one embodiment, springs may be mounted on the part of the transducer frame 110 farther away from the cleaning element than the second elastic members 105A and the magnets for pre-tightening. Only when the force F1 on the cleaning element is greater than the start-up force F4 of the cleaning element, the proximal second elastic members and the distal second elastic members can generate the displacement Y2 and displacement Y3, respectively.
As the force F1 increases, the forces F2 and F3 related to the elastic members will increase, and the increased F2 and F3 will cause the second elastic members to yield and lose their elasticity. In the present disclosure, the transducer device is further provided with a maximum force limiting portion that limits the force F1 to the maximum force F1M, that is, the transducer device is configured to have the maximum force F1M. In the embodiment of
For the electric toothbrush, in one embodiment, the maximum force F1M of the cleaning element ranges from 2.5 N to 10 N, and the start-up force F4 of the cleaning element is greater than or equal to 0 N and less than or equal to 2 N. As the force F1 on the cleaning element exceeds the maximum force F1M of the cleaning element and continues to increase monotonically, the handle housing or a part stationary relative to the handle housing constrains the transducer 7, and the displacement Y2 and displacement Y3 no longer change monotonically.
Based on the harmonic vibration analysis and mechanical analysis above, the force F1 on the cleaning element 3 will cause additional bending deformation of the first elastic members 104A and 104B. However, since the present disclosure introduces the second elastic members 105A and 105B to balance the force and force moment caused by the force F1 on the cleaning element 3, the additional bending deformation of the first elastic members 104A and 104B caused by the force F1 on the cleaning element 3 is greatly reduced, and the transducer 7 can work in the harmonic vibration state for a long life, and the second distal elastic members 105B have a limited impact on the spring stiffness coefficient at the natural frequency of the transducer, making the frequency adjustment of the transducer 7 easy. The first elastic members 104A and 104B and the second elastic members 105A and 105B may be formed by an injection molding process, and the transducer 7 is easy to manufacture.
As a variant of the first embodiment, there may be only one first elastic member, such as only one upper first elastic member 104A located on the left side of the driving shaft in
As another variant of the first embodiment, there may be only two second elastic members. The two second elastic members include one second elastic member 105A and one second elastic member 105B, for example, only one second elastic member 105A located on the left side of the driving shaft in
In other variations, the second elastic members may be located on the same side of the median plane P, or may be located on the same side of a perpendicular plane perpendicular to the median plane P and including the longitudinal axis L2.
In one embodiment, positions of the magnet, the driving coils, and the elastic members may be changed relative to the cleaning element 3, for example, the magnet and the driving coils are closer to the cleaning element 3, or the magnet and the driving coils are between the two second elastic members.
In the existing transducer device of the cleaning appliance, the fixed end or stationary end of the elastic member is located on the longitudinal axis of the driving shaft, acn is a distance from the driving force to the longitudinal axis of the driving shaft and is also a in the formula for calculating the stiffness coefficient of the elastic member, the force couple of the driving force is the driving force multiplied by acn, and acn needs to be large enough while maintaining a smaller driving force to ensure a sufficient force couple. In order to maintain a suitable stiffness coefficient of the elastic member, the size of the elastic member needs to be slightly larger. In addition, since the other end of the elastic member is fixedly coupled to the transducer transmission arm, the size of the existing transducer device is larger.
In this embodiment, the first elastic members 104 thus bear the electromagnetic torque M1 on the driving shaft. There are two frame fastening arms 113 distributed on the transducer frame 110. The two frame fastening arms 113 are respectively fixedly coupled to the other edges 106 of the corresponding first elastic members 104A and 104B. The edges 107 of the first elastic members 104A and 104B are fixedly coupled to the transducer frame portion 112. The transducer frame portion 112 enclosing the driving shaft encloses part of the driving shaft 110. The first elastic members 104A and 104B extend between the frame fastening arms 113 and the transducer frame portion 112 enclosing the driving shaft. The distance from the longitudinal axis L2 of the driving shaft to the edge 106 of the first elastic member is a in the formula for calculating the stiffness coefficient of the elastic member. The distance from the longitudinal axis L2 of the driving shaft to the other end 106 of the first elastic member has no direct relationship with the force arm of the electromagnetic force couple M1. Therefore, the distance from the longitudinal axis L2 of the driving shaft to the edge 106 of the first elastic member may be small enough, the size of the elastic member may be smaller, and the overall size of the transducer 7 may be smaller, to realize miniaturization of the cleaning apparatus.
In the first embodiment, when the transducer 7 is in a harmonic vibration state, the staggered distribution of the second elastic members 105A and the plastic second elastic members 105B along the longitudinal axis L2 of the driving shaft is used to realize amplification of the displacement Y3 caused by the force F1 on the cleaning element, to implement detection of the force F1 on the cleaning element. Detection of the force F1 on the cleaning element is required in some cleaning appliances, such as in electric toothbrushes, and an excessive force F1 on the cleaning element may damage the gums, so it is necessary to remind the user of the amount of the force F1. However, in some other applications, the cleaning appliance does not have a strong requirement for the detection of the force F1 on the cleaning element, but it is hoped that the transducer and the cleaning assembly are within a harmonic vibration range, and the force F1 on the cleaning element can be greater. To this end, the present disclosure provides another solution, which is to replace the materials of all the second elastic members in the above embodiments with metal, that is, a fourth embodiment of the transducer device shown in
In the fourth embodiment, the transducer 7′ includes a driving shaft 501, two proximal elastic members 505A distributed along a longitudinal axis L2 of the driving shaft, two distal elastic members 505B distributed along the longitudinal axis L2 of the driving shaft, magnets 502 and 503, and a transducer frame 510. The two magnets 502 and 503 are both fixed to the transducer frame 510. The material of the transducer frame 510 is plastic. The driving shaft 501, the proximal elastic members 505A, and the distal elastic members 505B are coupled together by means of the transducer frame 510. The magnets 502 and 503 are fixedly coupled, by means of glue, screws, or injection molding, to the tail of the transducer frame away from the cleaning element.
In the fourth embodiment, an elastic assembly of the transducer 7′ should include at least one proximal elastic member 505A and one distal elastic member 505B, and the one second proximal elastic member 505A and the one second distal elastic member 505B are respectively located on two opposite sides of a median plane P where the longitudinal axis L2 of the driving shaft is located. The one proximal elastic member 505A and the one distal elastic member 505B that are distributed on the two sides of the median plane P can withstand electromagnetic forces from two sides of the longitudinal axis L2 of the driving shaft, to balance forces of the transducer and reducing noise and impact.
In the fourth embodiment of the present disclosure, the transducer 7′ is provided with two proximal elastic members 505A and two distal elastic members 505B. The proximal elastic members 505A and the distal elastic members 505B have different inclination angles and are staggered from front to back along the longitudinal axis L2. The proximal elastic members 505A are closer to the proximal end of the driving shaft 501 than the distal elastic members 505B.
Similar to the structure in the first embodiment, the transducer frame 510 includes a frame portion 512 enclosing the driving shaft and frame fastening arms 513, and frame protrusions 511 protrude from the frame fastening arms 513. The proximal elastic members 505A and the distal elastic members 505B are respectively fixedly coupled to the frame protrusions 511 and the frame portion 512 enclosing the driving shaft.
As shown in
The elastic members 505A and 505B are roughly cuboids, a distance of each of the elastic members 505A and 505B from the frame protrusion 511 to the transducer frame portion 512 enclosing the driving shaft is the length of the elastic member, a distance of each of the elastic members 505A and 505B along the direction of the longitudinal axis of the driving shaft is the width of the elastic member, and the length of the remaining dimension of the cuboid is the thickness of the elastic member. A plane formed by the length and the width of each of the elastic members 505A and 505B is an elastic member plane. The elastic member plane is a plane that connects the respective frame protrusion 511 and the transducer frame portion 512 enclosing the driving shaft. In one embodiment, an angle between the plane and the longitudinal axis L2 of the driving shaft is less than 30 degrees. In this embodiment, angles between the planes of the four elastic members 505A and 505B and the longitudinal axis L1 of the cleaning element are δ1, δ2, δ3, and δ4, respectively. In this embodiment, δ1, δ2, δ3, and δ4 are all equal to 60 degrees. In other words, angles between the median plane P and the planes of the elastic members 505A and 505B are 30 degrees. It should be understood that, in other alternative embodiments, δ1, δ2, δ3, δ4 may be set to different values.
In the fourth embodiment, the materials of both the proximal elastic members 505A and the distal elastic members 505B are metal. The elastic members 505A and 505B may form two separate elastic bodies along the longitudinal axis as shown in
As shown in
The motion analysis of the transducer 7′ in the fourth embodiment is similar to the motion analysis of the transducer 7 in the first embodiment, and will not be described again.
In the fourth embodiment according to the present disclosure, the materials of the proximal and distal elastic members 505A and 505B are metal. According to the principle of solid mechanics, in a bending elastic deformation state, the elastic members are equivalent to linear springs. Taking a cuboid elastic member as an example, the stiffness coefficient of a linear spring equivalent to the elastic member is K=3*E*Iz/(a3),
When the driving frequency f0 is equal to the mechanical natural frequency fn, the mechanical portion is in forced resonant motion. When the alternating current I with the frequency of f0 passes through the driving coils, the transducer 7′ and the cleaning assembly are subjected to electromagnetic forces with the frequency of f0, and the frequency f0 of the driving force is between 85% and 115% of the natural frequency fn of the transducer 7′. According to the principle of simple harmonic vibration, generally, when the frequency f0 of the driving force is between 85% and 115% of the mechanical natural frequency fn, it may be considered that the mechanical portion is in forced harmonic motion, and the electrical energy of harmonic motion and resonant motion is converted into mechanical energy with a high efficiency.
Similarly, referring to
In one embodiment, a distance between the equivalent force F2 on the proximal elastic members 505A and the equivalent force F3 on the distal elastic members 505B is particularly important for the force moment balance. Through a large number of experiments and based on the feasibility of the production process, along the direction of the longitudinal axis L2 of the driving shaft, a distance between a center line L5 of the proximal elastic member and a center line L6 of the distal elastic member is 3.5 mm or more, and the center line refers to a second elastic member plane center line that is located on the plane of the elastic member and points from the frame fastening arm 513 to the transducer frame portion 512 enclosing the driving shaft. As shown in
As a variation of the fourth embodiment of the present disclosure, there may be only two elastic members 505. The two elastic members 505 include one proximal elastic member 505A and one distal elastic member 505B, for example, only one proximal elastic member 505A located on the left side of the driving shaft in
The distribution and positions of the magnets are similar to the analysis in
Similar to the first embodiment, the metal proximal elastic members 505A and distal elastic members 505B in the fourth embodiment can also identify the force F1 on the cleaning element. For the force F1 on the cleaning element, the maximum force F1M of the cleaning element ranges from 3 N to 15 N, and the start-up force F4 of the cleaning element is greater than or equal to 0 N and less than or equal to 2.5 N.
The transducer device according to the present disclosure introduces elastic members arranged in a staggered manner along the driving shaft to balance the force and force moment caused by the force F1 on the cleaning element, and reduces additional bending deformation of the elastic members caused by the force F1 on the cleaning element 3, to make the transducer work in the harmonic vibration state for a long life. In one embodiment, it is ensured that the transducer and the cleaning assembly are within the harmonic vibration range, and the force that can be applied on the cleaning element can be greater. In addition, the use of the arrangement of the elastic members according to the present disclosure can realize miniaturization of the cleaning apparatus.
The energy transfer efficiency in the harmonic vibration state or resonant state is very high. In the existing driving structure using bearings (such as ball bearings), constraint members such as bearings are provided to prevent the cleaning apparatus from movement other than rotational motion. However, this constraint will bring about noise and energy loss, and also increased costs. According to the present disclosure, due to rational configuration of the elastic members and the permanent magnets, the transducer can rotate smoothly, to eliminate some constraint members that must be provided for realizing the rotational motion of the cleaning appliance. Due to the rational configuration of the permanent magnets, the resulting electromagnetic force on the transducer 7 and the transducer is approximately zero. In addition, the torque acting on the transducer 7 and the transducer is skillfully utilized, and the constraint structure can be omitted, thus making the cleaning appliance have a more compact structure, rotate more smoothly, and have less noise.
The present disclosure has been disclosed above in terms of the embodiments which, however, are not intended to limit the present disclosure, and possible changes and alterations without departing from the spirit and scope of the present disclosure. Hence, any alterations, equivalent changes and modifications which are made to the above-mentioned embodiments in accordance with the embodiments of the present disclosure and without departing from the content of the embodiments of the present disclosure, will fall within the scope of protection defined by the claims of the present disclosure.
Number | Date | Country | Kind |
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202110719558.5 | Jun 2021 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2022/101744 | 6/28/2022 | WO |