A flat vibration motor and a manufacturing method thereof

Abstract

The present invention belongs to the technical field of micro-vibration motors, and specifically is a flat vibration motor and a manufacturing method thereof. The flat vibration motor comprises an upper housing and a lower housing, which are buckled together to form a receiving space, a stator assembly and a rotor assembly are arranged in the receiving space, the stator assembly comprises a flexible circuit board and a coil, the rotor assembly comprises an elastic member, a magnet and a plastic sealing member, bosses are respectively arranged at the center positions of the upper housing and the lower housing toward the receiving space, a groove is arranged in the middle of the boss, the rotor assembly is fixed in the receiving space by the elastic member and the grooves of the upper housing and the lower housing, the number of magnets is arranged corresponding to the number of coils, the present invention drives the rotor to swing by changing the current direction of the stator coil, and realizes motor resonance by combining the inherent resilience of the elastic member, the flat vibration motor provided by the present invention has a long service life, a fast starting response and a strong vibration sense.

Description

Technical Field

[0001] The invention belongs to the technical field of micro vibration motors, and in particular relates to a flat vibration motor and a manufacturing method thereof. Background Art

[0002] With the development of communication technology, more and more electronic products have entered people's lives, especially portable consumer electronic products, such as mobile phones, handheld game consoles or handheld multimedia entertainment devices. In these portable consumer electronic products, micro vibration motors are generally used for vibration feedback, such as incoming call notifications on mobile phones and vibration feedback on game consoles.

[0003] Traditional flat motors mostly use brush contact to change the direction of current, which leads to short life, low reliability, and high risk of sparks. Flat vibration motors do not have the defect of generating sparks due to commutation. Brushless flat vibration motors are gradually replacing brushless flat motors and are being adopted by more and more electronic products. Summary of the invention

[0004] The object of the present invention is to provide a flat vibration motor with long service life, high reliability and fast starting response and a manufacturing method thereof.

[0005] In order to achieve the above technical objectives, the present invention uses the following technical solutions:

[0006] A flat vibration motor comprises an upper shell and a lower shell, the upper shell and the lower shell are buckled together to form a receiving space, a stator assembly and a rotor assembly are arranged in the receiving space, the stator assembly comprises a flexible circuit board and a coil, the rotor assembly comprises an elastic member, a magnet and a plastic sealing member, bosses are respectively arranged at the center positions of the upper shell and the lower shell toward the receiving space, a groove is arranged in the middle of the bosses, the rotor assembly is fixed in the receiving space by the elastic member and the grooves of the upper shell and the lower shell, and the number of magnets is arranged corresponding to the number of coils.

[0007] Furthermore, the elastic member includes an upper end, a middle portion and a lower end, the upper end of the elastic member is inserted into the groove of the upper housing, the lower end of the elastic member is inserted into the groove of the lower housing, the middle portion of the elastic member is fixedly combined with the plastic sealing member, and the length of the lower end of the elastic member is greater than the length of the upper end of the elastic member.

[0008] Furthermore, the diameters of the two ends of the plastic sealing member are larger than the diameter of the middle part, the two ends are elliptical, a first through hole is provided at the center of the middle part, the two ends of the ellipse are symmetrically arranged with the first through hole, magnets are built in at the two ends of the plastic sealing member, and the middle part of the elastic member is placed in the first through hole of the plastic sealing member.

[0009] Furthermore, a magnetic conductive sheet is provided on the surface of the plastic sealing component facing the stator assembly, the shape of the magnetic conductive sheet is corresponding to the plastic sealing component, a second through hole is provided in the middle part of the magnetic conductive sheet, blind grooves are provided at both ends of the magnetic conductive sheet, the blind grooves fix the magnets, and the stator assembly is arranged at intervals on the other side of the magnetic conductive sheet.

[0010] Furthermore, the upper shell is cylindrical with one end open, a first boss is provided at the center of the inner surface of the top wall of the upper shell, the first boss is provided with a first groove, a notch is provided at the edge of the open end of the upper shell, and a first marking position is provided at the edge of the outer surface of the top wall of the upper shell corresponding to the notch.

[0011] Furthermore, the lower housing is in the shape of a circular plate, a second boss is provided at the center of the lower housing, a second boss is provided with a second groove, and a second marking position is provided at the edge of the lower housing.

[0012] Furthermore, the flexible circuit board is provided with a third through hole and an external power supply unit, the boss of the lower shell passes through the third through hole to fix the flexible circuit board on the lower shell, the external power supply unit extends from the notch of the upper shell, and the coil is placed on the flexible circuit board and located on the periphery of the third through hole.

[0013] A method for manufacturing a flat vibration motor comprises the following steps:

[0014] Step 1: Assemble the rotor assembly:

[0015] a1. Use positioning mold to fix magnets and elastic parts;

[0016] a2. Place the whole in an injection mold to form a plastic seal and an integrally formed rotor assembly;

[0017] Step 2: Stator assembly:

[0018] The flexible circuit board is attached to the lower housing, and the coil is bonded to the flexible circuit board to form a stator assembly;

[0019] Step 3: Motor assembly:

[0020] The lower end of the elastic member of the rotor assembly is inserted into the groove of the lower housing, the upper housing is buckled and fixed on the lower housing, and the upper end of the elastic member is inserted into the groove of the upper housing to complete the assembly of the flat vibration motor.

[0021] Further, the rotor assembly is assembled:

[0022] a1. Use positioning mold to fix magnets, elastic parts and magnetic conductive sheets;

[0023] a2. Place the whole in an injection mold to form a plastic-sealed part and an integrally formed rotor assembly.

[0024] The flat vibration motor and the manufacturing method thereof provided by the present invention have the following beneficial effects:

[0025] 1. The structure of the flat vibration motor is innovatively designed in principle. The rotor assembly and the stator assembly are designed in coordination. The flat motor brushes are eliminated. Coils and external AC drive are used. The elastic parts are fixedly inserted into the positioning grooves of the upper and lower casings. Unlike flat motors that use bearings for rotation, the flat vibration motor has a longer life and faster starting response.

[0026] 2. The flat vibration motor has a simple structure and process, uses fewer parts, and has a greatly reduced scrap rate. In particular, the elastic parts use their inherent resilience and change the direction of the stator coil current to drive the rotor to swing, causing the motor to resonate and produce a stronger vibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative work.

[0028] Figure 1 This is a schematic diagram of the three-dimensional structure of a flat vibration motor.

[0029] Figure 2 It is a schematic diagram of the three-dimensional structure of the upper casing.

[0030] Figure 3 Schematic diagram of the exploded structure of a flat vibration motor.

[0031] Figure 4 Schematic diagram of the cross section of a flat vibration motor.

[0032] Figure 5 It is a schematic diagram of the structure of the stator assembly combined with the lower casing.

[0033] Figure 6 It is a schematic diagram of the elastic member structure.

[0034] Figure 7 This is a schematic diagram of the three-dimensional structure of a flat vibration motor with the upper casing removed.

[0035] Figure 8 This is a schematic diagram of the three-dimensional structure of a flat vibration motor with the upper casing and magnetic plate removed.

[0036] Fig. 9 Schematic diagram of the cross section of a single-coil flat vibration motor.

[0037] Fig.10 This is a schematic diagram of the three-dimensional structure of a single-coil flat vibration motor with the upper casing removed.

[0038] Figure markings: 100-upper housing, 200-lower housing, 300-magnet, 400-plastic sealing part, 500-elastic part, 600-magnetic conductive sheet, 700-coil, 800-flexible circuit board, 101-first boss, 102-first groove, 103-notch, 104-first marking position, 401-first through hole, 601-second through hole, 602-blind groove, 801-third through hole, 201-second boss, 202-second groove, 203-second marking position, 501-upper end of elastic part, 502-middle part of elastic part, 503-lower end of elastic part. DETAILED DESCRIPTION

[0039] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] The present invention is further described in detail below with reference to the accompanying drawings.

[0042] Example 1

[0043] See also Figures 1 to 7 A flat vibration motor includes an upper shell 100 and a lower shell 200. The lower end of the upper shell 100 is open. The upper shell 100 and the lower shell 200 are buckled together to form a receiving space. A stator assembly and a rotor assembly are arranged in the receiving space. The rotor assembly is arranged above the stator assembly.

[0044] The stator assembly includes a flexible circuit board 800 and a coil 700, and the rotor assembly includes an elastic member 500, a magnet 300, a magnetic conductive plate 600 and a plastic package 400. The upper housing 100 and the lower housing 200 are provided with bosses at the center positions thereof toward the accommodation space, and a groove is provided in the middle of the bosses. The rotor assembly is fixed in the accommodation space by the elastic member 500 and the grooves of the upper housing 100 and the lower housing 200. The number of magnets 300 is set corresponding to the number of coils 700. The elastic member 500 fixedly supports the rotor assembly and is respectively fixed in the grooves of the upper housing 100 and the lower housing 200. The structure of the flat vibration motor is innovatively designed. The flat vibration motor drives the rotor assembly to swing according to the inherent resilience of the elastic member and changes the direction of the current of the stator coil, so that the motor resonates.

[0045] The plastic sealing part 400 and the elastic part 500 of the rotor assembly are fixedly arranged crosswise and vertically, and the magnets 300 are built into the two ends of the plastic sealing part 400; a magnetic conductive sheet 600 is arranged in contact with the surface of the plastic sealing part 400 facing the stator assembly, and the shape of the magnetic conductive sheet 600 is arranged corresponding to the plastic sealing part 400. The magnetic conductive sheet 600 has a magnetic conductive function and can prevent magnetic leakage; the plastic sealing part 400 provides mechanical assembly positioning for the positioning of the magnet 300 and the magnetic conductive sheet 600. The plastic sealing part 400 provides process production reliability and ease of operation between the various components of the rotor assembly, thereby ensuring the overall integrity of the rotor assembly and stability during resonance.

[0046] The elastic member 500 is made of a metal material with resilience, and includes an upper end, a middle part and a lower end. The upper end 501 of the elastic member is inserted into the groove of the upper housing 100, and the lower end 503 of the elastic member is inserted into the groove of the lower housing. The middle part 502 of the elastic member is fixedly combined with the plastic package 400. The middle part 502 of the elastic member is an integrally formed expansion part or a recessed part. The cross-sectional area of ​​the middle part of the elastic member is greater than or less than the cross-sectional area of ​​the upper and lower ends, ensuring a larger area for combining with injection molding, and preventing the elastic member 500 from loosening up and down, achieving better fixation and support for the rotor assembly, improving the consistency of the overall movement of the elastic member 500 and the rotor assembly, and providing a basic guarantee for the stability of the motor resonance. The length of the lower end 503 of the elastic member is greater than the length of the upper end 501 of the elastic member. The large length of the lower end of the elastic member 500 is mainly to provide space for the stator assembly to be set at intervals. The elastic member 500 provides a rebound force for the swing of the rotor assembly. The elastic member 500 drives the rotor assembly to swing through its inherent rebound force and changes the direction of the stator coil current, causing the motor to resonate and produce a strong vibration.

[0047] After injection molding, the horizontal diameters of the two ends of the plastic sealing part 400 are larger than the diameter of the middle part, and the two ends are elliptical. The two ends of the plastic sealing part 400 with a large diameter form a gap with the middle part of the plastic sealing part 400 with a small diameter. The two ends of the plastic sealing part 400 have magnet fixing grooves, and the two ends of the plastic sealing part 400 provide positioning for the magnet 300. The plastic sealing part 400 is a combined structural part of the rotor assembly, which can ensure the consistency of the rotor assembly. A first through hole 401 is provided at the center of the middle part of the plastic sealing part 400. The shape of the first through hole 410 is consistent with the shape of the middle part of the elastic part 500, and the two ends of the ellipse are symmetrically arranged with the first through hole 401. A second through hole 601 is provided at the center of the magnetic conductive sheet 600 close to the lower surface of the plastic sealing part 400. The first through hole 401 and the second through hole 601 are connected, and the elastic part 500 passes through the first through hole 401 and the second through hole 601 at the same time. The middle part 502 of the elastic member is placed in the first through hole 401 of the plastic package 400, and the second through hole 601 stops at the expansion part of the middle part 502 of the elastic member. The middle part 502 of the elastic member plays the role of axially positioning the magnetic conductive sheet and the plastic package. The position setting of the middle part 502 of the elastic member determines the distance between the rotor assembly and the stator assembly.

[0048] Blind grooves 602 are provided at both ends of the surface of the magnetic conductive sheet 600 facing the plastic package, and the blind grooves 602 fix the magnet 300. The blind grooves 602 at both ends are symmetrically arranged with the second through hole 601 as the center, and the stator assembly is arranged at intervals on the other side of the magnetic conductive sheet 600.

[0049] The upper shell 100 is cylindrical with one end open. A first boss 101 is provided at the center of the inner surface of the top wall of the upper shell 100 facing the accommodating space. A first groove 102 is provided in the center of the first boss 101. The first groove 102 facilitates the installation of the upper end 501 of the elastic member. A notch 103 is provided at the edge of the open end of the upper shell 100, that is, a notch 103 is provided at one end of the opening of the upper shell. A first marking position 104 is provided at the edge of the outer surface of the top wall of the upper shell corresponding to the notch 103. The first marking position 104 is used to prevent mistakes and improve the recognition of automated production and assembly.

[0050] The lower housing 200 is in the shape of a circular plate. A second boss 201 is provided at the center of the lower housing 200 toward the accommodation space. A second groove 202 is provided at the center of the second boss 201. The second groove 202 is convenient for fixing the lower end 503 of the elastic member to the lower housing 200. A second marking position 203 is provided at the edge of the lower housing 200. The second marking position 203 is visible on both sides of the lower housing 200. The second marking position 203 on the inner surface of the lower housing 200 indicates the mounting of the flexible circuit board 800. The second marking position 203 on the outer surface is used for indicating the notch 103 of the upper housing 100. The first marking position 104 is set corresponding to the second marking position 203.

[0051] The first groove 102 and the second groove 202 fix the axial and circumferential freedom of the elastic member 500 , and provide a good support point for the rebound of the elastic member 500 and the swing of the rotor assembly.

[0052] The flexible circuit board 800 of the stator assembly is provided with a third through hole 801 and an external power supply unit (not shown), the second marking position 203 indicates the extension direction of the external power supply unit, the second boss 201 of the lower housing 200 passes through the third through hole 801 to fix the flexible circuit board on the lower housing 200, and the coil 700 is placed on the flexible circuit board 800 and is located at the periphery of the third through hole 801. When the upper and lower housings are assembled, the external power supply unit extends from the notch 103 of the upper housing 100. The flexible circuit board 800 is provided with a soldering pad (not shown), which is used for internal and external electrical connection.

[0053] In this embodiment, the coil 700 is two hollow ovals, respectively located on both sides of the third through hole. The two coils 700 are bonded or glued to the flexible circuit board 800, corresponding to the magnet 300 of the rotor assembly. When the power is connected, the coil and the magnet generate a magnetic field force, and the rotor assembly swings left and right. Combined with the rebound force of the elastic part 500, the flat vibration motor resonates, thereby enhancing the driving force and vibration experience of the motor.

[0054] The flat vibration under this implementation scheme eliminates the rotating bearing of the traditional flat motor, thereby reducing the friction mechanical noise between the rotor shaft and the bearing, and between the shaft and the upper and lower casings during movement, thereby increasing the life of the flat vibration motor, increasing reliability, fast starting response, and strong vibration. At the same time, the flat vibration motor has a simple structure and process, uses fewer parts, and the scrap rate is greatly reduced, making the flat vibration motor low in cost.

[0055] Example 2

[0056] See also Figure 8 In the solution of Example 1, the magnetic conductive sheet 600 is eliminated.

[0057] Example 3

[0058] See also Fig. 9 and Fig.10 In this embodiment, the coil 700 is one and is located on one side of the third through hole 801 of the flexible circuit board 800, and the magnet 300 corresponding to the coil 700 is set as one. The plastic package under this embodiment is eccentrically set to achieve a stronger vibration. The second marking position 203 of the lower housing 200 can be set as a protrusion extending from the edge of the lower housing, and at the same time plays a role in supporting the external power supply part of the flexible circuit board 800. In this embodiment, the magnetic conductive sheet 600 can be set or not.

[0059] It is worth noting that, in other embodiments, the coils 700 may be an even number, and the magnets of the rotor assembly are arranged corresponding to the number of coils.

[0060] In the above-mentioned embodiments 1 to 3, the N / S of the magnet 300 corresponds to the N / S of the coil 700. The change in the direction of the AC current in the coil 700 causes the N / S of the coil 700 to change, that is, the rotor is driven to swing by changing the current direction of the coil. At the same time, combined with the inherent rebound force of the elastic part, the motor resonates to achieve a stronger vibration experience.

[0061] See also Figures 1 to 10 The rotor swing of the single-coil and double-coil embodiments of the flat vibration motor can be driven by changing the current direction of the coil. The manufacturing method of the flat vibration motor includes the following steps:

[0062] Step 1: Assemble the rotor assembly:

[0063] a1. Use a positioning mold to fix the magnet 300 and the elastic member 500;

[0064] a2. Place the whole in an injection mold to form a plastic seal and an integrally formed rotor assembly;

[0065] Step 2: Stator assembly:

[0066] The flexible circuit board 800 is attached to the lower housing, and the coil 700 is bonded to the flexible circuit board 800 to form a stator assembly;

[0067] Step 3: Motor assembly:

[0068] The lower end of the elastic member 500 of the rotor assembly is inserted into the groove of the lower housing 200, the upper housing 100 is buckled and fixed on the lower housing 200, and the upper end of the elastic member 500 is inserted into the groove of the upper housing 100, completing the assembly of the flat vibration motor.

[0069] In the first and third embodiments, the magnet 300 and the elastic member 500 of the rotor assembly are first fixed, and then the magnet 300 and the elastic member 500 are integrally injection molded to form a plastic package, thereby integrally forming the rotor assembly. In this embodiment, the rotor assembly is not provided with a magnetic conductive sheet 600. Figure 8 As shown, the rotor assembly is finally subjected to performance testing.

[0070] Furthermore, on the basis of the first embodiment in step 1, a magnetic conductive sheet 600 is added to form a rotor assembly of the second embodiment:

[0071] a1. Use positioning mold to fix magnets, elastic parts and magnetic conductive sheets;

[0072] a2. Place the whole in an injection mold to form a plastic-sealed part and an integrally formed rotor assembly.

[0073] In the second embodiment, the rotor assembly is additionally provided with a magnetic conductive sheet 600. The magnet 300, the elastic member 500 and the magnetic conductive sheet 600 of the rotor assembly are first fixed, and then the magnet 300, the elastic member 500 and the magnetic conductive sheet 600 are integrally placed in an injection mold to perform integral injection molding of the rotor assembly. Figure 7 As shown, the rotor assembly is finally subjected to performance testing.

[0074] In addition, the counterweight block can be made of a heavy alloy material to increase its vibration and provide a strong motor vibration sensation, or it can be replaced with other commonly used materials.

[0075] The description of the above embodiments is only used to help understand the method of the present invention and its core idea, and is not used to limit the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A flat vibration motor, characterized in that: The flat vibration motor comprises an upper housing and a lower housing, which are buckled with the lower housing to form a receiving space, a stator assembly and a rotor assembly are arranged in the receiving space, the stator assembly comprises a flexible circuit board and a coil, the rotor assembly comprises an elastic member, a magnet and a plastic sealing member, bosses are respectively arranged at the center positions of the upper housing and the lower housing to the receiving space, a groove is arranged in the middle of the boss, the rotor assembly is fixed in the receiving space by the cooperation between the elastic member and the grooves of the upper housing and the lower housing, the number of magnets is arranged corresponding to the number of coils, the elastic member comprises an upper end, a middle part and a lower end, the upper end of the elastic member is inserted into the groove of the upper housing, the lower end of the elastic member is inserted into the groove of the lower housing, the middle part of the elastic member is fixedly combined with the plastic sealing member, the length of the lower end of the elastic member is greater than the length of the upper end of the elastic member; the middle part of the elastic member is an integrally formed expansion part, and the cross-sectional area of ​​the middle part of the elastic member is greater than the cross-sectional area of ​​the upper and lower ends; the diameters of the two ends of the plastic sealing member are greater than the diameter of the middle part, the two ends are elliptical, and a first through hole is arranged at the center position of the middle part , the two ends of the ellipse are symmetrically arranged with the first through hole, the two ends of the plastic sealing part are built-in with magnets, the middle part of the elastic part is placed in the first through hole of the plastic sealing part, the surface of the plastic sealing part facing the stator assembly is fitted with a magnetic conductive sheet, the shape of the magnetic conductive sheet is arranged corresponding to the plastic sealing part, the middle part of the magnetic conductive sheet is arranged with a second through hole, the two ends of the magnetic conductive sheet are provided with blind grooves, the blind grooves fix the magnets, and the stator assembly is arranged at intervals on the other side of the magnetic conductive sheet; the second through hole stops at the expansion part in the middle of the elastic part, the upper shell is a cylinder with an opening at one end, a first boss is provided at the center position of the inner surface of the top wall of the upper shell, the first boss is provided with a first groove, a notch is provided at the edge of the open end of the upper shell, and a first marking position is provided at the edge position of the outer surface of the top wall of the upper shell corresponding to the notch, the lower shell is a circular plate, a second boss is provided at the center position of the lower shell, the second boss is provided with a second groove, the first groove and the second groove fix the axial and circumferential freedom of the elastic member, and a second marking position corresponding to the first mark is provided at the edge position of the lower shell.

2. A flat vibration motor as claimed in claim 1, characterized in that: The flexible circuit board is provided with a third through hole and an external power supply unit. The boss of the lower shell passes through the third through hole to fix the flexible circuit board on the lower shell. The external power supply unit extends out from the notch of the upper shell. The coil is placed on the flexible circuit board and is located on the periphery of the third through hole.

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