JP4367515B2 - Manufacturing method of speaker diaphragm and speaker diaphragm, speaker and electronic device formed thereby - Google Patents

Description

  The present invention relates to a method for manufacturing a speaker diaphragm and a speaker diaphragm, a speaker, and an electronic device formed thereby.

  In recent years, with the increase in demand for mobile phones and notebook computers, high productivity is also demanded for speakers used in these. In order to meet such market demands, in a method for manufacturing a speaker diaphragm, a compressed air molding method that is excellent in low cost has been mainly performed.

  FIG. 4 is a cross-sectional view of a mold used in a method for manufacturing a speaker diaphragm by a conventional compressed air molding method.

  That is, in a conventional method for manufacturing a speaker diaphragm, a first mold 1 having a desired mold and a second mold 2 provided to face the first mold 1 are: The resin film 3 is clamped while applying temperature by heating the mold, and further, air is supplied from a duct 4 provided in the second mold 2, and air pressure is applied to the resin film 3 to form the first mold 1. It was molded along with.

In addition, as this prior art document, patent document 1 is mentioned, for example.
Japanese Patent Laid-Open No. 3-133616

  However, when the resin film 3 is formed into a deep diaphragm shape, in the conventional method for manufacturing a diaphragm for a speaker, the resin film 3 is stretched more than necessary, so that the film material is torn.

  In view of this point, conventionally, it has been dealt with by multi-stage molding in which the pressure by compressed air is applied stepwise and the resin film 3 is stretched and molded little by little. However, multi-stage molding is time-consuming and excellent in productivity. It wasn't.

  Accordingly, an object of the method for manufacturing a speaker diaphragm according to the present invention is to increase the productivity of the speaker diaphragm.

In order to achieve this object, in the method for producing a resin plate according to the present invention, a first mold having a deep drawing mold and a deep drawing portion of the first mold are opposed to each other. The first mold and the second mold are formed by a molding machine having a second mold having a projection provided and a second mold having an air supply duct provided on the projection. A first step of supporting a resin film between the first mold and the second mold in an open state; a second step of clamping the first mold and the second mold; By pulling the outer periphery of the resin film into the chamber between the first mold and the second mold with the pressure of the compressed air generated by supplying air from the duct , the resin film is prevented from extending too much. molded in close contact with the resin film in the deep drawing part of the mold of the first mold while It is to produce a diaphragm for a speaker through the third step.

  With the above configuration, the productivity of the speaker diaphragm manufacturing method according to the present invention can be increased.

  This is because the speaker diaphragm is formed by a molding machine in which a convex portion is provided on the second mold.

  That is, when the first mold and the second mold are clamped, the resin film is drawn into the deep drawing portion of the first mold by the convex portion provided in the second mold, and the compression is performed. The resin film is not stretched more than necessary during molding by air pressure. As a result, it is possible to reduce the possibility of occurrence of defects such as breakage in the resin film, and it is not necessary to perform multi-stage molding over time unlike the conventional manufacturing method. It is possible to increase the productivity.

  Hereinafter, the structure of the molding machine used for the manufacturing method of the speaker diaphragm in the embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the molding machine used for the method for producing a resin plate in the embodiment of the present invention comprises a first mold 5 and a second mold 7 having a convex portion 6 at the center.

  On the lower surface of the first mold 5, there is provided a molding die 8 molded in the shape of a desired speaker diaphragm, and the shape of the molding die 8 is transferred to the resin film 9. A recessed deep drawing portion 10 is provided in the center of the mold 8, and a back pressure hole 11 is provided so as to penetrate from the deep drawing portion 10 to the back surface. The back pressure hole 11 sucks air when the speaker diaphragm is molded and jets air after molding the resin plate. Further, the first mold 5 is provided with a first outer portion 12 protruding so as to surround the deep drawing portion 10. The first outer portion 12 prevents air from leaking outside during molding. Although not shown, a heater for heating the first mold 5 is installed on the back of the first mold 5 before molding the resin plate.

  The second mold 7 has a convex portion 6 that protrudes opposite to the deep drawing portion 10 of the first mold 5. The convex portion 6 has a duct 13, and air for molding is ejected from the second mold 7 toward the resin film 9 through the duct 13. Further, similarly to the first outer portion 12 of the first mold 5, the second die 7 is provided with a second outer portion 14 around the convex portion 6. As shown in FIG. 2, the second outer portion 14 is sealed between the first mold 5 and the second mold 7 by contacting through the resin film 9 when the molds are clamped together. A chamber 15 is formed. Further, like the first mold 5, although not shown, a heater is installed on the back of the second mold 7.

  Hereinafter, the procedure of the method for manufacturing the speaker diaphragm in the embodiment of the present invention will be described with reference to the drawings.

  First, in the first step, the desired transfer positions on the mold 8 and the resin film 9 coincide with each other with the first mold 5 and the second mold 7 opened as shown in FIG. In addition, a resin film 9 is supported between the first mold 5 and the second mold 7. In addition, before the 1st process, the 1st metal mold | die 5 and the 2nd metal mold | die 7 are heated to the temperature more than the glass transition point of the resin film 9 with the heater (not shown). In the present embodiment, since PEI (polyetherimide) is used for the resin film 9, the heating temperature of the first mold 5 and the second mold 7 is higher than the glass transition point (220 ° C.) of PEI. It was 230 degreeC.

  Next, in the second step, the first mold 5 and the second mold 7 are clamped as shown in FIG. At this time, the resin film 9 is in contact with the convex portion 6 of the second mold 7 and further begins to soften due to the heat generated by the first mold 5 and the second mold 7. Then, the softened resin film 9 is brought into close contact with the mold 8 to some extent by sucking air from the back pressure hole 11. Here, the first outer portion 12 and the second outer portion 14 are in contact with each other through the resin film 9 to form a sealed chamber 15 between the first mold 5 and the second mold 7. is doing.

  In the third step, compressed air is generated in the sealed chamber 15 by the air blown out from the duct 13 provided in the convex portion 6 provided in the second mold 7, and the pressure of the compressed air is further generated. A resin film 9 is brought into close contact with the mold 8. As a result, the shape of the mold 8 is transferred to the resin film 9. Further, during this molding, a stress is generated in the resin film 9 in the direction of the duct 13 for ejecting air, so that the outer periphery of the resin film 9 is drawn to the inside from the outside of the chamber 15 to some extent.

  Finally, after the temperature of the resin film 9 is lowered below the glass transition point, the first mold 5 and the second mold 7 are opened. Further, air is injected from the back pressure hole 11, and the resin film 9 to which the shape of the mold 8 is transferred is peeled from the first mold 5. As a result, a speaker diaphragm having a desired shape can be obtained.

  Hereinafter, the effect by the manufacturing method of the speaker diaphragm in the embodiment of the present invention will be described.

  First, productivity can be improved in the method for manufacturing a speaker diaphragm in the embodiment of the present invention.

  This is because the speaker diaphragm is manufactured by the second mold 7 provided with the convex portions 6.

  In other words, the resin film 9 is drawn into the deep drawing part 10 in advance by the time of molding shown in FIG. 3 by the convex part 6, and it is possible to prevent the resin film 9 from extending too much when air is injected from the duct 13. . That is, it is not necessary to stretch and mold the resin film 9 over time by multistage molding as in the conventional method for manufacturing a speaker diaphragm, and productivity can be improved.

  Moreover, it is desirable to provide the duct 13 for ejecting air in the convex part 6. This is because the resin film 9 can be brought into close contact with the deep drawing portion 10 located above the convex portion 6 during molding by blowing air from the duct 13 provided on the convex portion 6. This is because the shape can be sufficiently transferred to the resin film 9. Furthermore, the duct 13 is provided on the convex portion 6 and air is jetted to generate a stress in the direction of the convex portion 6 on the resin film 9 so that the resin film 9 can be drawn into the chamber 15 from the outside. As a result, the possibility of damage due to the resin film 9 being stretched too much can be reduced, and the quality of the speaker diaphragm can be ensured.

  Further, in the method for manufacturing the speaker diaphragm in the embodiment of the present invention, the temperature of the first mold 5 and the second mold 7 is not less than the glass transition point of the resin film 9 before the first step. Is heated. As a result, the sheet-like resin film 9 softens as the first mold 5 and the second mold 7 approach in the second step, and in the third step, the resin film 9 has a glass transition point or higher. When the temperature is reached, the shape of the mold can be transferred. Therefore, the productivity of the speaker diaphragm can be improved.

  The first mold 5 and the second mold 7 are heated by a heater disposed on the back of the first mold 5 and the second mold 7. Accordingly, in the second process and the third process, the first mold 5 and the second mold 7 are separated from the fixed heater, and therefore the first mold 5 and the second mold are gradually used. The temperature of 7 decreases. As a result, in the third step, the temperature of the first mold 5 and the resin film 9 becomes a temperature below the glass transition point, and the resin film 9 is solidified in a state where the shape of the mold 8 is transferred. That is, in the method for manufacturing the speaker diaphragm in the embodiment of the present invention, a resin plate can be manufactured at low cost without requiring an apparatus for cooling the resin film 9, and the speaker diaphragm can be produced. Can be improved.

  In the method for manufacturing the speaker diaphragm in the embodiment of the present invention, the pressure applied to the resin film 9 is set to 0.8 MPa or more. That is, by forming the pressure applied to the resin film 9 at 0.8 MPa or more, the resin film 9 can be more closely attached to the forming die 8 and the deep drawing portion 10, and the forming die 8 having a complicated shape is obtained. Can be molded with high accuracy. As a result, occurrence of defects in the speaker diaphragm can be suppressed, and productivity can be improved.

  As described above, according to the method for manufacturing a speaker diaphragm in the embodiment of the present invention, the productivity can be improved, and thus it is particularly useful in manufacturing a small speaker diaphragm that often uses a resin film. It is.

  Further, according to the speaker diaphragm manufacturing method in the embodiment of the present invention, it is possible to provide a speaker diaphragm excellent in quality, so the speaker manufactured by the resin plate manufacturing method of the present invention. It is possible to improve the quality of a speaker using a vibration plate for an automobile and an electronic device using the speaker.

  According to the resin plate manufacturing method of the present invention, the productivity of the speaker diaphragm can be improved. Especially, the speaker diaphragm having a small and complicated shape and the speaker diaphragm having a deep diaphragm shape can be obtained. Useful for production.

Sectional drawing of the molding machine in the 1st process of the manufacturing method of the diaphragm for speakers in one embodiment of this invention Sectional view of the molding machine in the second step Sectional view of the molding machine in the third step Sectional view of a mold used in a conventional method for producing a resin plate

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 1st metal mold | die 6 Protruding part 7 2nd metal mold | die 8 Mold 9 Resin film 10 Deep drawing part 11 Back pressure hole 12 1st outer part 13 Duct 14 2nd outer part 15 Chamber

Claims (7)

A first mold having a deep-drawn mold;
A molding having a convex portion provided opposite to the deep drawing portion in the molding die of the first mold and a second die having an air supply duct provided on the convex portion. A method for manufacturing a speaker diaphragm by a machine,
A first step of supporting a resin film between the first mold and the second mold with the first mold and the second mold opened;
A second step of clamping the first mold and the second mold;
By pulling the outer periphery of the resin film into the chamber between the first mold and the second mold with the pressure of compressed air generated by supplying air from the duct , the resin film becomes A method for manufacturing a speaker diaphragm, comprising a third step of forming the resin film in close contact with the deeply drawn portion of the mold of the first mold while preventing it from being excessively stretched . The speaker diaphragm according to claim 1, further comprising a heating step of heating the first mold and the second mold to a temperature equal to or higher than a glass transition point of the resin film before the first step. Manufacturing method. The heating in the heating step is performed by a heater disposed on the back of the first die and the second die, and after the heating step, the first die is moved from the heater to the second die. The method for manufacturing a speaker diaphragm according to claim 1, wherein the speaker diaphragm is moved in the direction of. The method for manufacturing a speaker diaphragm according to claim 1, wherein the pressure by the compressed air is 0.8 MPa or more. The speaker diaphragm manufactured by the manufacturing method of the speaker diaphragm as described in any one of Claims 1-4 . A speaker configured using the speaker diaphragm according to claim 5 . The electronic device comprised using the speaker of Claim 6 .

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