Patent ID: 12238474

DETAILED DESCRIPTION OF EMBODIMENTS

Technical solutions in embodiments of the present invention will be clearly and completely described with reference to accompany drawings of the present invention. Obviously, the described embodiments are only some embodiments rather than all embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by skilled persons in the art without making any creative efforts fall into the scope of protection of the present invention.

With reference toFIGS.1-4, the present invention provides a speaker box100including a sound unit10, a housing20and a magnetic circuit coupling valve4.

The sound unit10is fixedly accommodated in the housing20. The sound unit10includes a bracket1, a vibration system2and a magnetic circuit system3having a magnetic gap30, the vibration system2and the magnetic circuit system3are fixed to the bracket1.

The vibration system2includes a diaphragm21, a sound coil22and an elastic support component23.

The diaphragm21is fixed to the bracket1.

The sound coil22is fixed to the diaphragm21. The sound coil22is inserted in the magnetic gap30to drive the diaphragm21to vibrate and sound.

The elastic support component23is fixed to the bracket1and is connected to an end of the sound coil22away from the diaphragm21. The elastic support component23includes an elastic member231having one end fixed to the bracket1and another end fixed to an end of the sound coil22away from the diaphragm21, and an auxiliary diaphragm232connected on a side of the elastic member231away from the diaphragm21. On the one hand, the elastic support component is used to strengthen a vibration effect of the diaphragm21, thereby improving acoustic performance of the speaker box100. On the other hand, the elastic support component is used to balance swinging of the vibration system2, thereby improving stability of the speaker box100.

In some embodiments, the elastic member231is a flexible circuit board. The sound coil22and the elastic member231are electrically connected to each other. On the one hand, the elastic member is used to improve vibration strength and balance of the vibration system2, and to inhibit swinging. On the other hand, the elastic member is used to connect the sound coil22to an external power supply, thereby avoiding a risk that a wire of the sound coil is prone to break when a wiring structure of the sound coil is lead to the power supply.

The magnetic circuit system3is used to drive the vibration system2to vibrate and sound. The magnetic circuit system3includes a yoke31, a primary magnet32fixed to the yoke31, a secondary magnet33spaced from the primary magnet32to form the magnetic gap30and a secondary magnetic conductive plate34fixed on a side of the secondary magnet33away from the yoke31.

In some embodiments, the yoke31is fixed to the bracket1.

In some embodiments, the primary magnet32is in a form of a rectangle. There are two secondary magnets33arranged on either sides of the primary magnet32. The two secondary magnets33are arranged on either sides of a long axis of the primary magnet32. There are two elastic support components23that are arranged on either sides of a short axis of the primary magnet32.

The housing20includes a top cover203and a bottom cover201.

The top cover203is pressed to the diaphragm21and forms a front cavity204with the diaphragm21. The front cavity204is used to improve high-frequency acoustic performance of the speaker box100. Sound holes2030are defined in the top cover203. The front cavity204is in communication with the outside through the sound holes2030. This structure enables the front cavity204to form a front sound structure for high-frequency sound through the sound holes2030.

The bottom cover201is fixed to the bracket1. The bottom cover201, the bracket1and the magnetic circuit system3form a rear cavity202. The rear cavity202is used to improve low-frequency acoustic performance of the speaker box100.

The bottom cover201includes a bottom cover plate2011arranged to face to and separate from the yoke31, and a bottom cover side wall2012that bends at a periphery of the bottom cover plate2011and extends from the periphery along an outer surface of the sound unit10, the bottom cover side wall2012is fixedly connected to the bracket1, and one or more leakage holes2010are defined through the bottom cover side wall. The rear cavity202is in communication with the outside through the leakage holes2010.

A plurality of leakage holes2010may be holes formed on a thin wall and be arranged in a form of a square array, a circular array or the like. In some embodiments, a total area of the plurality of leakage holes2010is equal or similar to an area of the sound holes2030. This structure provides the plurality of leakage holes2010with an area similar to an area of a receiver functioning as a telephone receiver. In this embodiment, a total area of the plurality of leakage holes2010is configured to be equal to the area of the sound holes2030, in this way, the speaker box100can have fine acoustic performance.

In some embodiments, the leakage holes2010cross through the bottom cover side wall2012. That is, the leakage holes2010are defined in the bottom cover side wall2012. This structure enables the rear cavity202to form a side sound structure of low-frequency sound through the leakage holes2010.

The magnetic circuit coupling valve4is accommodated in the rear cavity202. In some embodiments, the magnetic circuit coupling valve4is arranged on a side of one of the two secondary magnets33away from the primary magnet32.

The magnetic circuit coupling valve4includes a support43, a negative stiffness diaphragm42and a coil41. The support43is fixed to the bracket1or the yoke31. The support43and the sound unit10are assembled as a single piece and are then installed to the speaker box100. In this embodiment, the support43is fixed to the bracket1.

The negative stiffness diaphragm42is fixed to the support43. The negative stiffness diaphragm42is arranged to face to and be separated from the leakage holes2010.

The coil41is fixed on a side of the negative stiffness diaphragm42close to the secondary magnet33, and is separated from the secondary magnet33.

In this embodiment, the coil41is shaped as a runway structure, and the secondary magnetic conductive plate34at least partially extends into the coil41. This structure can improve magnetic circuit performance of the magnetic circuit coupling valve4.

On a basis that the magnetic circuit coupling valve4takes the secondary magnet33of the magnetic circuit system3as a drive magnetic field, the magnetic circuit coupling valve4uses the coil41to drive the negative stiffness diaphragm42to achieve control of opening and closing of the leakage holes2010. The present invention is not limited to this. With Reference toFIG.5, in another embodiment, a magnetic circuit coupling valve4ais arranged on a single side of a yoke31a. A coil41ais superimposed on a secondary magnet33a, and a negative stiffness diaphragm42ais on a single side of the yoke31a.

The coil41receives an external control signal and generates an electromagnetic field with the secondary magnet33to drive the negative stiffness diaphragm42to abut on and seal the leakage holes2010to a closed state, or drive the negative stiffness diaphragm42to separate from the leakage holes2010to make the leakage holes2010open, or drive the negative stiffness diaphragm42to partially abut on the leakage holes2010to make the leakage holes2010partially open or closed. A working principle of the magnetic circuit coupling valve4is the same as that of the sound unit10. Specifically, an electromagnetic field is generated by the energized coil41and the secondary magnet33. The coil41moves under a Lorentz force. By inverting the normal phases and the opposite phases of current in the coil41, a direction of the force acting on the coil41changes, so that the coil can approach or depart from the leakage holes2010. The negative stiffness diaphragm42can seal the leakage holes2010. Use of the negative stiffness diaphragm42can optimize control on sound leakage and enhance acoustic isolation. In this way, the acoustic performance of the speaker box100can be improved. The structure as described above can achieve communication of the rear cavity202with the outside by accurately controlling the leakage holes2010through the magnetic circuit coupling valve4. Double steady states, i.e. a steady open states or a steady closed state of the magnetic circuit coupling valve4can be achieved by merely inputting an input control signal of an external linear voltage once for a short time, to control the magnetic circuit coupling valve to open or close. The magnetic circuit coupling valve4in the double steady states can save power consumption of the speaker box100, and have a stable performance. The negative stiffness diaphragm42is a macromolecular film. Electric magnetization and macromolecular film are applied to the speaker box100to achieve a moving structure, in this way, reliability can be improved. Moreover, during the control of partially open state or partially closed state of the leakage holes2010by the magnetic circuit coupling valve4, accurate control can be achieved by continuously inputting a small input control signal of an external linear voltage for a short time. The signal is determined by a stiffness coefficient of the negative stiffness diaphragm42and a driving force of the coil41. Depending on the value of the external linear voltage, an opening degree of the leakage holes2010can be controlled with a high accuracy, and a smart control of rear cavity of speaker can be achieved, thereby providing more sound modes and a better bass effect. In this way, the speaker box100can accurately control a state of communication of the rear cavity202with outside air, and the speaker box100can have good acoustic performance.

With reference toFIGS.6-7, the negative stiffness diaphragm42includes an elastic film422and a seal421for sealing the leakage holes2010.

The seal421is arranged to face to the leakage holes2010. A pre-pressure design of the seal421ensures that the closed state of the rear cavity202of the speaker box100would not change under an air pressure over 5000 Pa.

The elastic film422includes a first fixing portion1223, an elastic bending portion formed by bending and extending a periphery of the first fixing portion4223and a second fixing portion4221extending away from a side of the first fixing portion4223from the elastic bending portion, the second fixing portion is fixed to a side of the support43away from the secondary magnets33. The coil41is fixed to a side of the first fixing portion4223close to the secondary magnets33. The seal421is fixed to a side of the first fixing portion4223away from the secondary magnets33.

The first fixing portion4223is fixed to a side of the support43away from the secondary magnets33, the elastic bending portion4222extends, in a bending way, from the first fixing portion4223, and the second fixing portion4221extends from the elastic bending portion4222and is fixed to the seal421. The rear cavity202is in communication with the outside through the leakage holes2010.

In response to there being no current in the coil41, a distance between the second fixing portion4221and the seal421in a moving direction of the coil41is greater than a distance between the second fixing portion4221and the bottom cover side wall2012on which the leakage holes2010are formed in the moving direction of the coil41. With reference toFIG.8, the seal421of the negative stiffness diaphragm42is supported by the elastic film422, and is pressed to the bottom cover side wall2012. A distance between a position b of the second fixing portion4221and a position c (the position c is a position where the negative stiffness diaphragm42is not in a sealing state) of the first fixing portion4223is greater than a distance between the position b of the second fixing portion4221and a position c′ (the position c′ is a position where the negative stiffness diaphragm42is not in a sealing state) of the first fixing portion4223. With this arrangement, the negative stiffness diaphragm42can generate a negative stiffness, so as to achieve sealing on the bottom cover side wall2012by the seal421.FIGS.9-10are diagrams of a displacement of the first fixing portion4223from the position c to the position c′ and an elastic reaction force of the bottom cover side wall2012. According toFIGS.9-10, intervals in which both the stiffness and the displacement are negative after 1.6 seconds are referred to as negative stiffness intervals.

In some embodiments, the negative stiffness diaphragm42is implemented by pre-elongating a film. The pre-elongation of the film includes: on the basis of a distance h1between the position b and the position d of the bottom cover side wall2012, an elastic amplitude corresponding to a certain pre-pressure is added, thereby obtaining a distance h2between the position b and the position c. Then lengths of films on either sides are obtained through curvature integration.

The negative stiffness diaphragm42also can be implemented by bending inwards a film. With reference toFIG.11, bending inwards a film includes: a pre-stress is generated by performing extrusion on two ends of the elastic film422that is u-shaped towards the middle, thereby obtaining a negative stiffness. A flat member is obtained by blanking. Upon assembly, a pre-stress is achieved by limiting position i, position j and position k of the elastic film422.

In some embodiments, the negative stiffness diaphragm42is a symmetrical structure or an asymmetrical structure. When the negative stiffness diaphragm is a symmetrical structure, the negative stiffness diaphragm42is in a form of a bilaterally symmetrical or quadrilaterally symmetrical rectangle. When the negative stiffness diaphragm is an asymmetrical structure, the negative stiffness diaphragm42is in a form of a rectangle with four asymmetrical corners, or a side of the negative stiffness diaphragm may be fixed by a hinge and an opposite side of the negative stiffness diaphragm is in a negative stiffness bending form. Alternatively, the seal421is in a form of a triangle. When the seal is in a form of a triangle, a negative stiffness diaphragm provided with a hinge structure is formed on each side of the seal421. A bottom side of the triangle functions as a pre-pressure film, and a vertex of the triangle functions as a hinge film.

In some embodiments, the elastic support component23is provided with four pads230each arranged at a respective corner of the elastic support component23. The pads230are provided on the elastic member231electrically connected with the sound coil22and the coil41, respectively. The sound coil22has two wires each welded to a respective pad230of two of the four pads. The coil41has two wires each welded to a respective pad of the other two of the four pads230, or one of the two wires of the coil41is welded to one of the two pads230to which the two wires of the sound coil are welded, so as to share with the sound coil22one pad230that functions as a negative electrode. This structure may enable the wires of the coil41to individually use two unused pads230of the elastic support component23, or to share one pad230functioning as a negative electrode. In this way, a circuit connection structure of the speaker box100can be simple and be easy for connection.

In some embodiments, in order to improve sealing performance of the negative stiffness diaphragm42better, the speaker box100further includes a gasket5accommodated in the rear cavity202. The gasket5improves air impermeability between the negative stiffness diaphragm42and the bottom cover side wall2012. The gasket5is fixed to an inner side of the bottom cover side wall2012on which the leakage holes2010are formed. In order to improve the sealing performance of the negative stiffness diaphragm42better, a shape of the gasket5is matched with the bottom cover side wall2012. The gasket5may be any one of a rubber sheet, flexible foam, macromolecular gel or high-viscosity grease.

Compared with a related technology, in the speaker box according to the present invention, the magnetic circuit coupling valve is arranged in the rear cavity. The magnetic circuit coupling valve includes the support, the coil and the negative stiffness diaphragm. A plurality of leakage holes are formed in the bottom cover of the housing. The support is fixed to the bracket or the yoke. The negative stiffness diaphragm is fixed to the support. The coil is fixed on a side of the negative stiffness diaphragm close to the secondary magnet and is separated from the secondary magnet. The negative stiffness diaphragm faces to and is separated from the leakage holes. With the structure as described above, when the negative stiffness diaphragm is in operation, the coil receives an external control signal and generates an electromagnetic field with the secondary magnet to drive the negative stiffness diaphragm to abut on and seal the leakage holes to a closed state, or drive the negative stiffness diaphragm to separate from the leakage holes to make the leakage holes open, or drive the negative stiffness diaphragm to partially abut on the leakage holes to make the leakage holes partially open or closed. In other words, the negative stiffness diaphragm can seal the leakage holes. Use of the negative stiffness diaphragm can optimize sound leakage control and enhance acoustic isolation. In this way, the acoustic performance of the speaker box can be improved. In addition, the structure as described above can achieve communication of the rear cavity with the outside by accurately controlling the leakage holes through the magnetic circuit coupling valve. Double steady states, i.e. a steady open state or a steady closed state of the magnetic circuit coupling valve can be achieved by merely inputting an input control signal of an external linear voltage once for a short time, to control the magnetic circuit coupling valve to open or close. During the control of partially open state or partially closed state of the leakage holes by the magnetic circuit coupling valve, accurate control can be achieved by continuously inputting a small input control signal of an external linear voltage for a short time. The signal is determined by a stiffness coefficient of the negative stiffness diaphragm and a driving force of the coil. In this way, the speaker box can accurately control a state of communication of the rear cavity with outside air, and the speaker box can have good acoustic performance.

The above-described are only embodiments of the present invention. It should be noted that skilled persons in the art may make improvements without departing from the concept of the present invention. All these improvements fall into the scope of protection of the present invention.