A method to improve the concentricity of the voice coil in a speaker magnetic circuit

Abstract

This invention provides a method for improving the concentricity of the voice coil in a loudspeaker magnetic circuit, belonging to the field of acoustic technology. This invention primarily addresses the issue of concentricity between the magnetic circuit and the voice coil. It uses a CCD visual inspection device to detect the eccentricity direction of the relative positioning of the magnetic circuit or voice coil, classifying the eccentricity into two categories and placing them in different trays. Based on the detected voice coil eccentricity direction, different magnetic circuit schemes are selected for mating. This invention transforms the disordered combination of the voice coil and magnetic circuit into an ordered combination, allowing the eccentricity problem to be canceled out in the same direction, significantly improving the concentricity level after the voice coil and magnetic circuit are mated. Compared with existing technologies, this invention improves the concentricity of the mated magnetic circuit and voice coil from 0.08 to 0.04.

Description

Technical Field

[0001] This invention relates to a method for improving the concentricity of the voice coil in a speaker magnetic circuit. Background Technology

[0002] With the development of consumer electronics, the sound quality requirements for speakers are getting higher and higher. Conversely, the volume left for speakers is getting smaller and smaller. In order to obtain better sound quality in a limited space, one solution is to reduce the gap between the voice coil and the magnet to obtain a higher magnetic field strength (increase the BL value) and increase the speaker driving force to obtain higher speaker sound quality. However, due to material manufacturing tolerances, assembly tolerances and other reasons, the concentricity of the magnetic circuit and the voice coil is difficult to guarantee. Therefore, the smaller the magnetic gap, the lower the yield of the speaker and the greater the probability of quality problems.

[0003] Existing technical solutions:

[0004] ① Replacing molds with better ones improves material precision, and replacing equipment with better ones improves assembly precision. This solution places stringent requirements on molds, materials, and equipment, resulting in high costs and limitations due to the limited precision improvements of machine tools and other industrial mother machines. The highest concentricity of the relative positioning position of the voice coil can be achieved with current technology is 0.04, and the best concentricity of the relative positioning position of the magnetic circuit can also be achieved with 0.04. After the magnetic circuit and voice coil are engaged, the limit deviation of the voice coil-magnetic circuit concentricity is within 0.08.

[0005] ② Visual guidance positioning reduces the reliance on material precision, but increases assembly tolerance (because it adds a mechanism for gripping or sucking materials, a mechanism for adjusting material position, and the possibility of displacement during the transfer process after the product is fastened without a magnetic positioning structure). On the other hand, this solution eliminates the structural positioning of the magnetic circuit, and the magnetic circuit and the shell are only bonded by glue, so the reliability is relatively worse than the solution with structural positioning. At present, the industry standard for visual guidance magnetic circuit voice coil concentricity is 0.06 (not considering the possible displacement during the transfer process). Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the above-mentioned conventional technology and provide a method for improving the concentricity of the voice coil in the magnetic circuit of a speaker.

[0007] The objective of this invention is achieved through the following technical measures: a method for improving the concentricity of the voice coil in a speaker magnetic circuit, characterized in that:

[0008] Step 1: Bond and fix the center magnet assembly to the magnet cover to form the first assembly. The center magnet assembly includes a magnet bonded to the magnet cover and pole pieces provided on the magnet. Bond and fix the voice coil to the frame and diaphragm to form the second assembly.

[0009] Step 2: Using a CCD vision inspection device, the first component and the second component obtained in Step 1 are respectively inspected to detect the dimension from the edge of the electrode sheet to the edge of the magnetic cover, and the dimension from the edge of the voice coil to the inner edge of the frame.

[0010] Step 3: Determine the offset direction of the electrode relative to the magnetic shield based on the difference in size between the opposite edge of the electrode and the edge of the magnetic shield detected in Step 2. The offset directions are: upward offset a, downward offset d, left offset g, right offset h, upper left offset b, upper right offset c, lower left offset e, and lower right offset f.

[0011] The offset direction of the voice coil relative to the frame is determined based on the difference in size between the edge of the voice coil and the inner edge of the frame detected in step two. The offset directions are: upward offset i, downward offset l, left offset o, right offset p, upper left offset j, upper right offset k, lower left offset m, and lower right offset n.

[0012] Step 4: Determine the concentricity by dividing the absolute value of the dimensional difference obtained in Step 3 by 2. The concentricity should be ≤0.04.

[0013] Step 5: Using a CCD vision inspection device, arrange the components that meet the concentricity requirements and have the following misalignment types (upward a, upward left b, downward right f, and left g) in container A in an orderly manner, wherein the downward right f is rotated 180 degrees to be converted into the upward left b.

[0014] Using a CCD vision inspection device, the first component that meets the concentricity requirement and whose offset type is downward offset d, downward left offset e, upward right offset c, and right offset h are arranged in an orderly manner in container B, wherein the upward right offset c is rotated 180 degrees to be converted into downward left offset e.

[0015] Step Six: Using a CCD vision inspection device, place the different first components into the corresponding second components.

[0016] As an improvement, in step two, the positioning of the upper edge of the electrode to the upper edge of the magnetic cover is defined as dimension A; the positioning of the lower edge of the electrode to the lower edge of the magnetic cover is defined as dimension B; the positioning of the left edge of the electrode to the left edge of the magnetic cover is defined as dimension C; and the positioning of the right edge of the electrode to the right edge of the magnetic cover is defined as dimension D.

[0017] As a further improvement, when the result of subtracting dimension B from dimension A is negative, the electrode is determined to be deflected upward relative to the magnetic cover, which is called upward deflection a; when the result of subtracting dimension B from dimension A is positive, the electrode is determined to be deflected downward relative to the magnetic cover, which is called downward deflection d; when the result of subtracting dimension D from dimension C is negative, the electrode is determined to be deflected to the left relative to the magnetic cover, which is called left deflection g; when the result of subtracting dimension D from dimension C is positive, the electrode is determined to be deflected to the right relative to the magnetic cover, which is called right deflection h; when both upward and left deflection are satisfied, it is called upper left deflection b; when both upward and right deflection are satisfied, it is called upper right deflection c; when both downward and left deflection are satisfied, it is called lower left deflection e; when both downward and right deflection are satisfied, it is called lower right deflection f; when both upward and right deflection are satisfied, it is called upper right deflection c; when both downward and left deflection are satisfied, it is called lower left deflection e; when both downward and right deflection are satisfied, it is called lower right deflection f.

[0018] As a further improvement, in step two, the positioning from the upper edge of the voice coil to the lower inner edge of the frame is defined as dimension E; the positioning from the lower edge of the voice coil to the upper inner edge of the frame is defined as dimension F; the positioning from the left edge of the voice coil to the right inner edge of the frame is defined as dimension G; and the positioning from the right edge of the voice coil to the left inner edge of the frame is defined as dimension H.

[0019] As a further improvement, when the result of subtracting dimension F from dimension E is negative, the voice coil is determined to be tilted upward relative to the frame, which is called upward tilt i; when the result of subtracting dimension F from dimension E is positive, the voice coil is determined to be tilted downward relative to the frame, which is called downward tilt l; when the result of subtracting dimension H from dimension G is negative, the voice coil is determined to be tilted to the left relative to the frame, which is called left tilt o; when the result of subtracting dimension H from dimension G is positive, the voice coil is determined to be tilted to the right relative to the frame, which is called right tilt p; when both upward and left tilt are satisfied, it is called upper left tilt j; when both upward and right tilt are satisfied, it is called upper right tilt k; when both downward and left tilt are satisfied, it is called lower left tilt m; when both downward and right tilt are satisfied, it is called lower right tilt n.

[0020] As a further improvement, step six specifically includes:

[0021] When the second component has an upward bias type of i, the first component in container A is placed into the second component with an upward bias type of i.

[0022] When the second component has an offset type of upper left offset j, the first component in container A is placed into the second component with an offset type of upper left offset j.

[0023] When the second component is offset type up right offset k, rotate the first component in container B by 180° and place it into the second component with offset type up right offset k.

[0024] When the second component has a downward offset type of l, the first component in container B is placed into the second component with a downward offset type of l.

[0025] When the second component's offset type is lower left offset m, the first component in container B is placed into the second component with the offset type lower left offset m;

[0026] When the second component is offset type down right offset n, rotate the first component in container A by 180° and place it into the second component with offset type down right offset n.

[0027] When the second component has a left offset type of 0, the first component in container A is placed into the second component with a left offset type of 0.

[0028] When the second component has a right offset type of p, the first component in container B is placed into the second component with a right offset type of p.

[0029] As a further improvement, the result of subtracting the two dimensions is zero, and the offset type can be arbitrarily assigned to either the upper or lower offset.

[0030] As a further improvement, if the concentricity is greater than 0.04, the first or second component is determined to be defective.

[0031] Due to the adoption of the above technical solution, the advantages of the present invention compared with the prior art are:

[0032] This invention primarily addresses the concentricity issue between the magnetic circuit and the voice coil. It utilizes a CCD vision inspection device to detect the eccentricity direction of the magnetic circuit or voice coil relative to its positioning position. The eccentricities are categorized into two types and placed in different trays. Based on the detected voice coil eccentricity direction, different magnetic circuit schemes are selected for mating. This invention transforms the disordered combination of the voice coil and magnetic circuit into an ordered combination, allowing the eccentricity problem to be canceled out in the same direction, significantly improving the concentricity level after the voice coil and magnetic circuit are mated. Compared to existing technologies, this invention increases the concentricity of the mated magnetic circuit and voice coil from 0.08 to 0.04.

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0034] Appendix Figure 1 This is a schematic diagram of the product structure of the present invention;

[0035] Appendix Figure 2 This is a schematic diagram of the structure of the first component of the present invention;

[0036] Appendix Figure 3 This is the offset classification diagram of the first component of the present invention;

[0037] Appendix Figure 4 This is a schematic diagram of the structure of the second component of the present invention;

[0038] Appendix Figure 5 This is the offset classification diagram of the second component of the present invention;

[0039] Appendix Figure 6 This is a schematic diagram of the process of this invention. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0042] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0044] Example 1: As shown in the attached document Figure 1 - Appendix Figure 6As shown: A loudspeaker includes a frame 1, a voice coil 2, a diaphragm 3, a dome 4, a pole piece 5, a magnet 6, and a magnet cover 7.

[0045] A method to improve the concentricity of the voice coil in a speaker magnetic circuit.

[0046] Step 1: Bond and fix the central magnet assembly to the magnetic cover 7 to form the first assembly. The central magnet assembly includes a magnet 6 bonded to the magnetic cover 7 and pole pieces 5 provided on the magnet 6.

[0047] Step Two: The first component obtained in Step One is then inspected using a CCD visual inspection device (the CCD visual inspection device uses a machine to measure and judge instead of the human eye. The working principle of CCD visual inspection is that the captured object is converted into an image signal by the CCD image pickup device, and then sent to a dedicated image processing system. Based on pixel distribution and information such as brightness and color, it is converted into a digital signal. The image system performs various operations on these signals to extract the features of the target (such as area, quantity, position, length), and then, according to preset allowable ranges and other conditions, including size, angle, quantity, pass / fail, presence / absence, etc., to achieve automatic recognition. Then, the operation of the device is controlled on-site based on the judgment result). The detection position is the positioning position from the edge of the electrode 5 to the edge of the magnetic cover 7. The positioning from the upper edge of the electrode 5 to the upper edge of the magnetic cover 7 is defined as dimension A; the positioning from the lower edge of the electrode 5 to the lower edge of the magnetic cover 7 is defined as dimension B; the positioning from the left edge of the electrode 5 to the left edge of the magnetic cover 7 is defined as dimension C; and the positioning from the right edge of the electrode 5 to the right edge of the magnetic cover 7 is defined as dimension D.

[0048] Step 3: Calculate the offset direction and concentricity of the electrode 5 relative to the magnetic cover 7. If the result of subtracting dimension B from dimension A is negative, the electrode 5 is determined to be offset upwards relative to the magnetic cover 7, which is upward offset 'a'. If the result of subtracting dimension B from dimension A is positive, the electrode 5 is determined to be offset downwards relative to the magnetic cover 7, which is downward offset 'd'. If the result of subtracting dimension D from dimension C is negative, the electrode 5 is determined to be offset to the left relative to the magnetic cover 7, which is left offset 'g'. If the result of subtracting dimension D from dimension C is positive, the electrode 5 is determined to be offset to the right relative to the magnetic cover 7, which is right offset 'h'. The absolute value of the result divided by 2 should be ≤0.04; otherwise, the concentricity of the magnetic circuit assembly is considered NG, indicating a defective product.

[0049] The one that satisfies both upward and leftward deviation is upper-left deviation (b). Similarly, there are upper-right deviation (c), lower-left deviation (e), and lower-right deviation (f). If the difference between the two dimensions is 0, then it can be arbitrarily assigned to upper deviation (a) or lower deviation (d). (See attached) Figure 3 ).

[0050] Step 4: Arrange the components with the following offset types from Step 3: Upward offset a, Upward left offset b (downward right offset f rotated 180 degrees to become upward left offset b), and left offset g in container A in an orderly manner;

[0051] Arrange the components with the following offset types in container B in an orderly manner: downward offset (d), downward left offset (e) (upward right offset (c) rotated 180 degrees to become downward left offset (e)), and right offset (h).

[0052] Step 5: The CCD vision inspection equipment executes the logical conditions in Step 4 and places different first components into different containers.

[0053] Step 6: Attach and fix the voice coil 2 to the frame 1 and diaphragm 3 to form the second component. This step can be performed simultaneously with Step 1.

[0054] Step 7: The second component from Step 6 is inspected using a CCD vision inspection device. The inspection position is the distance from the edge of the voice coil 2 to the inner edge of the frame 1 (i.e., the positioning position of the magnetic cover 7). The distance from the upper edge of the voice coil 2 to the lower inner edge of the frame 1 is defined as dimension E; the distance from the lower edge of the voice coil 2 to the upper inner edge of the frame 1 is defined as dimension F; the distance from the left edge of the voice coil 2 to the right inner edge of the frame 1 is defined as dimension G; and the distance from the right edge of the voice coil 2 to the left inner edge of the frame 1 is defined as dimension H.

[0055] Step 8: Calculate the offset direction and concentricity of the voice coil 2 relative to the frame 1; if the result of subtracting dimension F from dimension E is negative, the voice coil 2 is determined to be offset upwards relative to the frame 1, which is upward offset i; if the result of subtracting dimension F from dimension E is positive, the voice coil 2 is determined to be offset downwards relative to the frame 1, which is downward offset l; if the result of subtracting dimension H from dimension G is negative, the voice coil 2 is determined to be offset to the left relative to the frame 1, which is left offset o; if the result of subtracting dimension H from dimension G is positive, the voice coil 2 is determined to be offset to the right relative to the frame 1, which is right offset p; the absolute value of the result divided by 2 should be ≤0.04, otherwise the concentricity of the component is determined to be NG and it is a defective product;

[0056] A value that simultaneously satisfies both upward and leftward deviation is designated as upward-left deviation j. Similarly, there are upward-right deviation k, downward-left deviation m, and downward-right deviation n. If the difference between the two dimensions is 0, then the value can be arbitrarily assigned to either upward deviation i or downward deviation l. (See attached) Figure 5 ).

[0057] Step Nine:

[0058] When the offset type in step eight is upper offset i, the first component in container A is used for combination.

[0059] When the offset type in step eight is upper left offset j, the first component in container A is used for combination.

[0060] When the offset type in step eight is upper right offset k, the first component in container B is rotated 180° and combined.

[0061] When the offset type in step eight is downward offset l, the first component in container B is used for combination.

[0062] When the offset type in step eight is lower left offset m, the first component in container B is used for combination.

[0063] When the offset type in step eight is down-right offset n, the first component in container A is rotated 180° and combined.

[0064] When the offset type in step eight is left offset o, the first component in container A is used for combination.

[0065] When the offset type in step eight is right offset p, the first component in container B is used for combination.

[0066] Step 10: The CCD vision inspection device executes the logical conditions of step 9 and places the different first components into the second component.

[0067] This invention primarily addresses the concentricity issue between the magnetic circuit and voice coil 2. It utilizes a CCD visual inspection device to detect the eccentricity direction of the magnetic circuit or voice coil 2 relative to its positioning position. The eccentricities are categorized into two types and placed in different trays. Based on the detected eccentricity direction of the voice coil 2, different magnetic circuit schemes are selected for mating. This invention transforms the disordered combination of voice coil 2 and magnetic circuit into an ordered combination, allowing the eccentricity problem to be canceled out in the same direction. This significantly improves the concentricity level after the voice coil 2 and magnetic circuit are mated. Compared to existing technologies, this invention increases the concentricity of the mated magnetic circuit and voice coil 2 from 0.08 to 0.04.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for improving the concentricity of the voice coil in a loudspeaker magnetic circuit, characterized in that: Step 1: Bond and fix the center magnet assembly to the magnet cover to form the first assembly. The center magnet assembly includes a magnet bonded to the magnet cover and pole pieces provided on the magnet. Bond and fix the voice coil to the frame and diaphragm to form the second assembly. Step 2: Using a CCD vision inspection device, the first component and the second component obtained in Step 1 are respectively inspected to detect the dimension from the edge of the electrode sheet to the edge of the magnetic cover, and the dimension from the edge of the voice coil to the inner edge of the frame. Step 3: Determine the offset direction of the electrode relative to the magnetic shield based on the difference in size between the opposite edge of the electrode and the edge of the magnetic shield detected in Step 2. The offset directions are: upward offset a, downward offset d, left offset g, right offset h, upper left offset b, upper right offset c, lower left offset e, and lower right offset f. The offset direction of the voice coil relative to the frame is determined based on the difference in size between the edge of the voice coil and the inner edge of the frame detected in step two. The offset directions are: upward offset i, downward offset l, left offset o, right offset p, upper left offset j, upper right offset k, lower left offset m, and lower right offset n. Step 4: Determine the concentricity by dividing the absolute value of the dimensional difference obtained in Step 3 by 2. The concentricity should be ≤0.

04. Step 5: Using a CCD vision inspection device, arrange the components that meet the concentricity requirements and have the following misalignment types (upward a, upward left b, downward right f, and left g) in container A in an orderly manner, wherein the downward right f is rotated 180 degrees to be converted into the upward left b. Using a CCD vision inspection device, the first component that meets the concentricity requirement and whose offset type is downward offset d, downward left offset e, upward right offset c, and right offset h are arranged in an orderly manner in container B, wherein the upward right offset c is rotated 180 degrees to be converted into downward left offset e. Step Six: Using a CCD vision inspection device, place the different first components into the corresponding second components.

2. The method for improving the concentricity of the voice coil in a speaker magnetic circuit according to claim 1, characterized in that: In step two, the distance from the upper edge of the electrode to the upper edge of the magnetic cover is defined as dimension A; the distance from the lower edge of the electrode to the lower edge of the magnetic cover is defined as dimension B; the distance from the left edge of the electrode to the left edge of the magnetic cover is defined as dimension C; and the distance from the right edge of the electrode to the right edge of the magnetic cover is defined as dimension D.

3. The method for improving the concentricity of the voice coil in a speaker magnetic circuit according to claim 2, characterized in that: If the difference between dimension A and dimension B is negative, the electrode is determined to be deflected upwards relative to the magnetic cover, which is called upward deflection a; if the difference between dimension A and dimension B is positive, the electrode is determined to be deflected downwards relative to the magnetic cover, which is called downward deflection d; if the difference between dimension C and dimension D is negative, the electrode is determined to be deflected to the left relative to the magnetic cover, which is called left deflection g; if the difference between dimension C and dimension D is positive, the electrode is determined to be deflected to the right relative to the magnetic cover, which is called right deflection h; if both upward and left deflection are satisfied, it is called upward left deflection b; if both upward and right deflection are satisfied, it is called upward right deflection c; if both downward and left deflection are satisfied, it is called downward left deflection e; if both downward and right deflection are satisfied, it is called downward right deflection f; if both upward and right deflection are satisfied, it is called upward right deflection c; if both downward and left deflection are satisfied, it is called downward left deflection e; if both downward and right deflection are satisfied, it is called downward right deflection f.

4. The method for improving the concentricity of the voice coil in a speaker magnetic circuit according to claim 1, characterized in that: In step two, the distance from the upper edge of the voice coil to the lower inner edge of the frame is defined as dimension E; the distance from the lower edge of the voice coil to the upper inner edge of the frame is defined as dimension F; the distance from the left edge of the voice coil to the right inner edge of the frame is defined as dimension G; and the distance from the right edge of the voice coil to the left inner edge of the frame is defined as dimension H.

5. The method for improving the concentricity of the voice coil in a speaker magnetic circuit according to claim 4, characterized in that: When the result of subtracting dimension F from dimension E is negative, the voice coil is determined to be tilted upward relative to the frame, which is upward tilt i; when the result of subtracting dimension F from dimension E is positive, the voice coil is determined to be tilted downward relative to the frame, which is downward tilt l; when the result of subtracting dimension H from dimension G is negative, the voice coil is determined to be tilted to the left relative to the frame, which is left tilt o. If the difference between dimension G and dimension H is positive, the voice coil is determined to be deflected to the right relative to the frame, which is right deflection p; if it is deflected upwards and to the left, it is upper left deflection j; if it is deflected upwards and to the right, it is upper right deflection k; if it is deflected downwards and to the left, it is lower left deflection m; and if it is deflected downwards and to the right, it is lower right deflection n.

6. The method for improving the concentricity of the voice coil in a speaker magnetic circuit according to claim 1, characterized in that: Step six specifically involves: When the second component has an upward bias type of i, the first component in container A is placed into the second component with an upward bias type of i. When the second component has an offset type of upper left offset j, the first component in container A is placed into the second component with an offset type of upper left offset j. When the second component is offset type up right offset k, rotate the first component in container B by 180° and place it into the second component with offset type up right offset k. When the second component has a downward offset type of l, the first component in container B is placed into the second component with a downward offset type of l. When the second component has a downward left offset type of m, the first component in container B is placed into the second component with a downward left offset type of m. When the second component is offset type down right offset n, rotate the first component in container A by 180° and place it into the second component with offset type down right offset n. When the second component has a left offset type of 0, the first component in container A is placed into the second component with a left offset type of 0. When the second component has a right offset type of p, the first component in container B is placed into the second component with a right offset type of p.

7. The method for improving the concentricity of the voice coil in a speaker magnetic circuit according to claim 1, characterized in that: The result of subtracting the two dimensions is zero, and the offset type can be arbitrarily assigned to either the upper or lower offset.

8. The method for improving the concentricity of the voice coil in a speaker magnetic circuit according to claim 1, characterized in that: If the concentricity is greater than 0.04, the first or second component is determined to be defective.

Images