TECHNICAL FIELD

The present disclosure relates to the technical field of electric toothbrush heads, in particular to a magnetically driven electric toothbrush head.

BACKGROUND

With the continuous improvement of the quality of life, electric toothbrushes have been vigorously promoted by the market. A typical electric toothbrush includes a brush head that produces high-frequency vibration through rapid rotation or vibration of a vibration unit, such that the toothpaste is instantly decomposed into tiny bubbles which penetrate into and thus clean crevices between teeth. At the same time, the vibration of bristles of the brush can promote the blood circulation of the mouth and has a massage effect on the gingival tissue.

The electric toothbrush includes the brush handle and the electric toothbrush head. At present, there are two ways for the brush handle to drive the electric toothbrush head to vibrate. The first is driven by vibration, concretely, the top of the brush handle is provided with a vibration unit. The vibration unit is directly inserted into the electric toothbrush head, and then the vibration of the vibration unit drives the electric toothbrush head to vibrate. The second is driven by magnetism, that is to say, an electromagnet is set in the brush handle, and a permanent magnet is set on the brush head of the electric tooth. Through the magnetic drive between the electromagnet and the permanent magnet, the brush handle is driven to rotate reciprocatingly.

In the existing technology, as for the magnetically driven electric toothbrush head, because the reciprocating rotation amplitude of the toothbrush head is not large enough, the use effect of electric toothbrush head is poor.

SUMMARY

It is desired to provide an improved magnetically driven electric toothbrush head.

The present invention provides a magnetically driven electric toothbrush head which comprises a brush body, a movable board arranged movably, and a screw cap. The screw cap has a cavity inside; a top of the screw cap has a top opening in communication with the cavity; an upper end of the brush body is provided with brush hair; the brush body is arranged above the screw cap, and an elastic cover is arranged between a lower end of the brush body and an upper end of the screw cap. Wherein a fixed frame is fixed inside the cavity of the screw cap, the movable board is movable reciprocating laterally after magnetic drive, two twisting plates are arranged in intervals between the fixed frame and the movable board, an upper end of the twisting plate is fixedly connected with the fixed frame and a lower end of the twisting plate is fixedly connected with the movable board, and a resistance of the twisting plate to distortion is less than the resistance to bending. Wherein the movable board is connected with a driving shaft, a lower end of the driving shaft is fixedly connected with the movable board, an upper end of the driving shaft extends upward through the fixed frame and the elastic cover and fixedly connected with a lower end of the brush body, the driving shaft is spaced from the fixed frame and the elastic cover respectively. Wherein a bottom of the movable board is provided with two permanent magnets, a lower end of the screw cap is fixed and connected to an upper end of a brush handle, when an electromagnet in the tooth handle is electrified, under a magnetic effect between the electromagnet and the two permanent magnets and a distortion limit of the twisting plates, the movable board drives the driving shaft and the brush body to rotate synchronously and reciprocatingly. Wherein an upper outer of the twisting plate is provided with a rubber sleeve to form a limiting section, a top of the rubber sleeve is fixedly connected with a bottom of the fixed frame, a lower part of the twisting plate is exposed to form a twisting section, when the twisting plate is twisted, a twisting amplitude of the twisting section is greater than that of the limiting section, a middle part of the twisting section is connected to the driving shaft with a rubber strip, one end of the rubber strip is fixedly connected to the driving shaft, and the other end of the rubber strip is wrapped in a middle part of the twisting section, and the rubber strip is movably connected to the twisting section.

In some embodiments, the movable board is provided, on its top, with an elastic plate with horizontal distortion due to compression, the elastic plate is movably arranged on the movable board, a lower end of the twisting section extends through the elastic plate and is fixedly connected with the elastic plate, a sector-shaped guide groove with an arc outer wall is defined in the elastic plate, the driving shaft movably moves through the arc-shape guide groove, and a radian of the arc-shaped outer wall of the sector-shaped guide groove is same as that of the reciprocating rotation of the driving shaft.

In some embodiments, an inner side of the sector-shaped guide groove has a short inner wall, an outer side of the sector-shaped guide groove has a long outer wall, a limit groove is defined in a middle of the short inner wall, the driving shaft is flat, an inner side of the driving shaft is embedded in the limit groove and is connected with an inner side of the limit groove, an outer side of the driving shaft is oriented towards the long outer wall, and a gap is formed between the driving shaft and the long outer wall. When the electromagnet in the brush handle is energized, under a magnetic effect between the electromagnet and the two permanent magnets and a twisting restriction of the twisting plate, and the outer side of the driving shaft rotates reciprocatingly with its inner side as a rotation center.

In some embodiments, a bottom end of the brush body has a ring bottom portion oriented downward, the elastic cover has a ring top portion abutting against the ring bottom portion of the brush body, an upper ring groove is defined in the ring bottom portion and is upward depressed, a lower ring groove is defined in the ring top portion and is downward depressed, and the upper ring groove is aligned with the lower ring groove. Wherein the upper ring groove is provided with a rolling ball that is capable of rolling circumferentially along the upper ring groove, and a lower side of the rolling ball is movably placed in the lower ring groove.

In some embodiments, a bottom end of the elastic cover has an annular step oriented downward, the annular step is connected to a top of the screw cap and is arranged around a top opening of the cavity, a connection part extends downward from the bottom end of the elastic cover, and the connection part extends through the top opening of the cavity, surrounds the periphery of the fixed frame, and is fixedly connected with the fixed frame.

In some embodiments, the driving shaft has a flat inserting section that extends upward through the elastic cover, a connecting channel is defined in the brush body for insertion of the flat inserting section, the connecting channel is arranged longitudinally and extends through a bottom of the brush body to form an insertion opening at the bottom of the brush body, a through groove transversely extends through the brush body, the through groove is filled with elastic rubber block which is in a compressed state. Wherein, a pressing wall is formed between the through channel and the connecting channel, the pressing wall has an internal pressing surface facing the connecting channel and an external pressing surface facing the through channel, a central part of the internal pressing surface is convexed towards the connecting channel to form a pressing bulge, the brush body has a limiting wall opposite to the pressing wall, and the pressing wall and the limiting wall are arranged on opposite sides of the through channel respectively. Wherein an inner side wall of the connecting channel has a straight pressing surface which is arranged facing to the internal pressing surface, the straight pressing surface extends along the axial direction of the connecting channel, the inserting section has two opposite insertion sides, and when the inserting section is inserted into the connecting channel via the insertion opening, one of the insertion sides of the inserting section contacts and abuts against the straight pressing surface, and the other of the insertion sides of the inserting section abuts against the pressing bulge.

In some embodiments, a thickness of the limiting wall is greater than that of the pressing wall.

In some embodiments, the through groove forms a groove opening on the outer wall of the brush body, the elastic rubber block has an end layer that seals the groove opening, the end layer is hardened, and an outer edge of the end layer is fixedly connected with the outer wall of the brush body.

In some embodiments, the pressing wall is curved, a middle part of the external pressing surface of the pressing wall is depressed toward the connecting channel to form a concaved groove corresponding to the pressing bulge, and the elastic rubber block fills the concaved groove.

In some embodiments, the external pressing surface has an end section in upper and lower parts of the concaved groove, the end section extends to the concaved groove and connects with the sidewall of the concaved groove, and along the extension direction of the end section to the concaved groove, the end section being inclined to the connecting channel.

