JP2002539988A - Method and apparatus for producing a plastic diaphragm for an electro-acoustic transducer - Google Patents

Abstract

(57) [Summary] An apparatus (1) and a method for manufacturing a plastic diaphragm (2) using a deep drawing portion (20) having a deep drawing mold (33) made of a sintered material, comprising: The air between the front face (34) of the mold and the base foil (10) facing the front face flows deep through the particle-free gaps formed between the coalesced particles (60) in the sintering material. It is discharged through the drawing die.

Description

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to a method for producing a diaphragm as defined in the preamble of claim 1.

The invention further relates to a device as defined in the preamble of claim 5.

The invention further relates to a diaphragm as defined in the preamble of claim 9.

[0004] Methods, devices and diaphragms as described above have been available from the applicant already for several years and are at least well known among the experts. Known methods and known devices have an air duct extending substantially in the direction of the deep drawing, for example formed by a hole having a diameter of about 0.15 mm, between the front and the rear of the deep drawing mold, A deep drawing die made of brass is used. The air duct allows the air between a certain length of foil and the deep-drawing mold to be expelled as quickly as possible from this area, i.e. the deep-drawing mold, through the air duct during the deep-drawing process. To In this configuration, air can only be exhausted through the air duct point by point, so air is exhausted point by point and the foil at the front of the deep drawing die is compared to the deep drawing die Contact unevenly. Another one
One problem is that during the deep-drawing process, the narrow air ducts are already covered with foil at an early stage, so that the remaining air cannot be discharged without interruption. This known configuration also requires relatively high pressure to ensure that the foil is pressed against the front of the deep drawing mold. In addition, relatively long cycle times are required. Furthermore, the air duct, although of small diameter, introduces irregularities in the diaphragm surface which cooperates with the front of the finished diaphragm deep drawing mold. The irregularities are convex protrusions on the diaphragm surface of the diaphragm caused by the foil partially penetrating into the air duct when manufacturing the diaphragm, resulting in permanent deformation.

An object of the present invention is to eliminate the above-mentioned problems, and to provide an improved manufacturing method and an improved manufacturing apparatus for manufacturing a diaphragm, and an improved diaphragm.

In order to achieve the above object in a method as defined at the beginning of claim 1, according to the invention, the features defined in claim 1 are provided.

To achieve the above object in a device as defined at the beginning of claim 5, according to the invention, the features defined in claim 5 are provided.

In order to achieve the above object in a diaphragm defined at the beginning of claim 9, according to the invention, the features defined in claim 9 are provided.

Given the above features according to the present invention, the relatively high speed of the air between a length of foil and the front of the deep drawing mold, and in particular in producing a plastic diaphragm, Simple means that a stable discharge is ensured, so that the foil is always pressed very evenly against the front of the deep-drawing mold and that the air ducts in the deep-drawing mold are never obstructed point by point and Achieved in a simple way. The use of deep-drawing dies made of sintered material makes it possible to use relatively low pressures compared to the previously known methods and to enable short cycle times. Furthermore, when a deep drawing mold made of a sintered material is used, since the deep drawing mold made of a sintered material has a completely uniform cross section without an air duct entrance, a convex surface is formed on the diaphragm surface of the manufactured diaphragm. Is not formed. A further advantage of the deep-drawing dies made of sintered material is that the production costs are considerably lower than the production of the known deep-drawing dies made of brass provided with narrow air ducts.

In the method and the device according to the invention, it has proven advantageous if the features as defined in claim 2 and claim 6 are additionally provided. By joining this useful part to a metal ring before the useful part of the foil that becomes the finished diaphragm is separated from the rest of the foil, the finished diaphragm is protected from damage and handled in a safe manner. In addition, a very important advantage is obtained because the finished diaphragm can simply be incorporated and held in an electro-acoustic transducer by means of a metal ring.

In the method and the device according to the invention, it has proven to be advantageous if the features as defined in claim 3 and claim 7 are additionally provided. Heating the foil to be deep-drawn ensures that the foil is deep-drawn particularly uniformly, which is very suitable for the high quality of the diaphragm.

The diaphragm of the present invention does not create any irregularities on the diaphragm surface, such as convex protrusions, whereby the diaphragm of the present invention has a particularly uniform shape in its thickness direction, Particularly suitable for high acoustic performance.

[0013] The above and further aspects of the present invention will become apparent by reference to the example embodiments described below.

The present invention will be described in more detail with reference to the drawings showing embodiments, but the present invention is not limited to the following embodiments.

FIG. 1 shows a manufacturing apparatus 1 for manufacturing a plastic diaphragm 2 having a given cross-sectional shape for an electroacoustic transducer (not shown). The diaphragm 2 is shown in FIG. The diaphragm 2 includes a curved central portion 4 that is rotationally symmetric about the diaphragm axis 3, a substantially flat annular intermediate portion 5, a curved peripheral portion 6, and a hollow cylindrical spacer portion 7 extending parallel to the diaphragm axis 3. And a mounting portion 8 extending perpendicularly to the diaphragm shaft 3. The annular intermediate portion 5 is connected to a movable coil (not shown). The attachment section 8 attaches the diaphragm 2 to the electroacoustic transducer.

The manufacturing apparatus 1 includes a number of parts described below, which are shown in FIG.

The production apparatus 1 has an arrangement means 9 for arranging an essentially flat foil 10 made of plastic. In the actually realized manufacturing apparatus 1, the arrangement means 9 is realized by a table called a so-called rotary table. The arrangement means 9 includes a first arrangement ring 11 and a second arrangement ring 12. The two arrangement rings 11 and 12
It is held coaxial with the diaphragm axis 3 by a method not shown, and the foil 10 is placed therebetween. This is shown in FIG. 1 as the position P1 of the arrangement means 9. The arrangement means 9 is movable in the direction indicated by the arrow 13 to a position P1.

In the case of the present embodiment, the disposing means 9 will be described in more detail below, but in order to supply a substantially flat plastic foil 10, Form.

The manufacturing apparatus 1 further includes a heating unit 14. The substantially flat foil 10 is supplied to the heating unit 14 by the arrangement means 9 in the direction indicated by the arrow 15. The heating section 14 has an infrared radiator 16 carried by a fixture 17. The heating section 14 further has a power supply 18 for the infrared radiator 16 connected to the infrared radiator 16 via a conductive connection 19. The flat foil section 10 is heated to a temperature within a given temperature range by the heating section 14, that is, the infrared radiator 16 of the heating section 14. By heating the foil part 10, the foil is slightly plastically deformed, and the foil 10 bends as shown in a position P2 in FIG.

The manufacturing apparatus 1 further includes a deep drawing unit 2 for performing deep drawing in a given deep drawing direction 21.
Contains 0. The deep drawing part 20 has a mold box 22 including a lower part 23 and an upper part 24. On the end face 26 of the lower part 23 facing the end face 25 of the upper part 24, a so-called O
A ring seal 27 called a ring is provided. The lower part 23 has a low pressure chamber 28. The upper part 24 has a high-pressure chamber 29. The lower part 23 moves in the direction indicated by the arrow 30 to the operating position shown in FIG. The upper part 24 also moves in the direction indicated by the arrow 31 to the operating position shown in FIG. When the lower part 23 and the upper part 24 are in the operating position, respectively, the intermediate area between the two end faces 25 and 26 is sealed by a seal 27.

When the lower part 23 moves to the rest position in the direction opposite to the arrow 30 and the upper part 24 respectively in the direction opposite to the arrow 31, the foil 10 is turned by the feeding means formed by the positioning means 9 into the arrow 32. Are transported to the deep drawing section 20 in the direction shown in FIG. The arrangement means 9 takes the position P3 shown in FIG.

The deep drawing section 20 has a deep drawing die 33 provided in the lower portion 23. The deep drawing die 33 has a front surface 34 having a cross-sectional shape corresponding to the cross-sectional shape of the diaphragm 2 and a back surface 35 spaced in the deep drawing direction 21. In the present embodiment, the holding means formed by the lower part 23, the seals 27 provided on the lower and upper parts, and the foil 10 supplied to the deep drawing part 20 by the arranging means 9 are formed on the front surface 34 of the deep drawing die 33. Is held in the opposite position.

The manufacturing apparatus 1, that is, the deep drawing unit 20 includes a vacuum generator 36, by which a partial vacuum is generated. The vacuum generator 36 is connected to a lower connecting portion 38 via an elastic tube 37, whereby the vacuum generator 36 is connected to the low-pressure chamber 28. The deep drawing die 33 is sucked by the vacuum generating device 36 in the region of the back surface 35 of the deep drawing die 33, and the air between the front face 34 of the deep drawing die 33 and the foil 10 facing the front face 34 is drawn by the deep drawing die. It is possible to pass through the deep drawing die 33 from the front surface 34 of the die 33 and discharge it to the back surface 35 of the deep drawing die 33.

The manufacturing apparatus 1, that is, the deep drawing unit 20 further includes a pressing device 39. A high pressure is generated by the pressure device 39. The pressurizing device 3 is connected to the connecting portion 4 of the upper portion 24 through the elastic tube 40.
1, whereby the pressurizing device 39 is connected to the high-pressure chamber 29. Pressurizing device 3
9, pressure is applied to the foil 10 facing the front face 34 of the deep drawing die 33,
4 can be pressed against the front surface 34 of the deep drawing die. By pressing the foil 10 against the front surface 34 of the deep drawing die 33 in this manner, the foil 10 is given a cross-sectional shape that matches the cross-sectional shape of the front surface 34 of the deep drawing die 33. At the position P3 shown in FIG. 1, the foil 10 has already been given a cross-sectional shape that matches the cross-sectional shape of the front surface 34 of the deep drawing die 33.

The production device 1 has a delivery means for delivering the foil 42 given a given cross-sectional shape from the deep drawing section 20 to further means of the device 1. In this embodiment, the sending means is formed by the arranging means 9 in the same manner as the supplying means. The transmission by the arranging means is performed in the direction indicated by the arrow 43.

The manufacturing apparatus 1 further includes joining means 44 for receiving the foil 42 having a given cross-sectional shape carried in the direction indicated by the arrow 43 from the deep drawing portion 20 and further receiving the metal ring 45. By means of the joining means 44, a useful part 46 of the foil 42 having a given cross-sectional shape and becoming the diaphragm 2 is joined to a metal ring 45 such that the metal ring 46 surrounds the useful part 46 of the foil 42. The coupling means 44 comprises a support means 47 movable in the direction indicated by the arrow 48 from the rest position to the operating position shown in FIG. The foil 42 at the position P4 which is the operation position is supported by the support means 47.
The joining means 44 further has an annular area 50 facing the support means 47 and an arrow 51.
A holding means 49 in the form of a pot which is movable from the rest position to the operating position shown in FIG. The holding means 49 holds the metal ring 45 such that the metal ring 45 contacts the foil 42 when moved in the direction indicated by the arrow 51. Therefore, before the metal ring 45 is brought into contact with the foil 42, the foil 4
An adhesive is applied to a region where the second metal ring 45 is disposed, and after the metal ring 45 is placed, adhesive bonding between the foil 42 and the metal ring 45 becomes possible.

When the metal ring 45 and the foil 42 are joined, the support means 47 moves in the direction opposite to the arrow 48, and the holding means 49 moves in the direction opposite to the arrow 51, and becomes the rest position. After that, the foil 42 provided with the metal ring 45 is moved by the arranging means 9 into an arrow 52.
Move to the position P5 in FIG.

The manufacturing apparatus 1 further includes a separating unit 53 at a position P5. The separating means 53 separates the useful portion 46 of the foil 42 from the remaining portion 54 of the foil 42 along a circular separating area extending radially outside the metal ring. The separating means is arranged and configured as follows. The separating unit 53 includes a laser beam source 55 provided on a rotatable support 55H, and generates a laser beam 56 as shown in FIG. The laser beam 56 is directed at the foil 42, allowing the remaining portion 54 of the foil 42 and the useful portion 46 of the foil 42 to be separated in a simple and accurate manner. When separated by the separating means 53, the metal ring 45 to which the foil 42 is bonded is held by further pot-shaped holding means 57 as shown in FIG. The further holding means 57 is arrow 5
In the direction indicated by 8, it moves from the rest position, not shown, to the operating position shown in FIG.

After being separated by the separating means 53, the further holding means 57 is movable in the direction indicated by arrow 59 to a position P6 in FIG. The diaphragm 2 formed from the metal ring 45 and the useful part of the foil 42 adhesively bonded to the metal ring 45 is kept in position P6. The finished diaphragm 2 with the metal ring 45 joined for holding and handling of the diaphragm 2 is moved from the position P6 shown in FIG. 1 in the direction indicated by the arrow 62 in a further position not shown, for example by a packaging device. Move to a further location for packaging.

In the manufacturing apparatus 1 shown in FIG. 1, the deep drawing part 20 is a deep drawing die 33 made of a sintered material.
It is advantageous to have FIG. 2 illustrates a deep drawing mold 33 made of a sintered material.
See As is apparent from FIG. 2, the deep drawing mold 33 has a particle-free gap between the particles 60 that have been united by sintering. This is known as a sintered material. The air between the front surface 34 of the deep drawing mold 33 and the foil 10 which is opposite to the front surface 34 and is already pressed against the front surface 34 of the deep drawing mold 33 in the drawing is the particles which are united by sintering. Through the particle-free gap between 60, it is possible to pass through the deep drawing mold 33, ie to be discharged in the direction indicated by the arrow 61 in FIG. This discharge is performed by a vacuum generator 36 not shown in FIG.

As can be seen from FIG. 2, the deep drawing part 20 is made of a sintered material and has a cross-sectional shape that matches the cross-sectional shape of the diaphragm 2 arranged in front of the die.
3 Such an arrangement has proven to be particularly advantageous in practice.

A deep drawing die made of a sintered material is formed of non-corrosive steel particles and is formed by sintering a steel grain. Alternatively, the deep drawing mold may be composed of other metal particles, such as brass particles, coalesced by sintering.

The manufacturing apparatus 1 of the present invention shown in FIG. 1 implements the method of the present invention for manufacturing a plastic diaphragm 2 for an electroacoustic transducer having a given cross-sectional shape. The method of the present invention has the processing steps described below.

A length of substantially flat plastic foil 10 is conveyed to a heating section 14 where the foil 10 is heated to a temperature within a desired given temperature range to promote plastic deformation of the foil 10.

Next, the foil 10 is conveyed to the deep drawing section 20, and the foil 10 is deep drawn so as to obtain the foil 42 having a given cross-sectional shape. To perform this deep drawing, a vacuum generator 3
6 is actuated and the air between the substantially undeformed foil 10 and the front face 34 of the deep-drawing mold 33 creates a particle-free gap formed between the sintered material particles 60 coalesced by sintering. Is discharged through. Further, the pressing device 39 is driven to generate a pressure in the high-pressure chamber 29 that is high enough to press the front surface 34 of the deep drawing die 33 so that the foil 10 is plastically deformed. During the deep drawing, the deep drawing die is heated to a given temperature, that is, a temperature in the range of 110 ° C. to 145 ° C. by a heating means (not shown).
The pressure in the high-pressure chamber 29 is in the range from 10 bar to 25 bar.

After deep-drawing the initially flat foil 10 to form a foil 42 having a given cross-sectional shape, the foil 42 is conveyed to the joining means 44 and the foil 42 is joined to the metal ring 45. . When the metal ring 45 and the foil 42 are joined, the foil 42 provided with the metal ring 45
Is carried to separating means 53, whereby the remaining portion 54 of the foil 42 is separated from the useful portion 46 of the foil 42, and then to the useful portion 46 of the foil 42, Further operation or processing is performed.

The production apparatus 1 of the present invention and the method of the present invention allow the air between the foil 10 and the front face 34 of the deep drawing die 33 to be formed at a relatively high speed and more particularly stable when forming the plastic diaphragm 2. In this way, it is ensured that the material is discharged through the deep-drawing mold 33, so that the foil 42 is always pressed very evenly against the front face 34 of the deep-drawing mold 33. Furthermore, this is achieved with relatively low pressures and relatively short cycle times, so that a high output is ensured each time unit.

[0038] The diaphragm of the present invention shown in FIG.
Is manufactured using the deep-drawing die 33 of this example, and has an especially important advantage that irregularities do not occur on the diaphragm surface of the manufactured diaphragm 2. Deep drawing mold 33
Is made of a sintered material and does not have an air duct for venting air, so that no irregularities caused by the duct occur when manufacturing the diaphragm 2.

[Brief description of the drawings]

FIG. 1 is a diagram showing an apparatus having a deep drawing portion and manufacturing a plastic diaphragm for an electroacoustic transducer using the method of the present invention.

2 is an enlarged view of FIG. 1 showing a part of the deep drawing portion in the apparatus of FIG. 1 having a deep drawing die of the deep drawing portion.

FIG. 3 is a view showing a diaphragm manufactured by the apparatus shown in FIG. 1;

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Claims (9)

[Claims] 1. A deep drawing is performed in a given deep drawing direction, and a front surface having a cross-sectional shape corresponding to a given cross-sectional shape of the diaphragm, and a back surface spaced from the front surface in the deep drawing direction. Transferring a substantially flat foil made of plastic and having a certain length to a deep drawing portion including a deep drawing mold having: and holding the foil at a position facing the front surface of the deep drawing mold. Suctioning the deep-drawing die in the area of the back surface of the deep-drawing die, and deep-drawing the air between the foils facing the front surface and the front surface of the deep-drawing die from the front surface. Driving a vacuum generator that generates a partial vacuum by discharging through the mold to the back of the deep drawing mold, and pressing the foil facing the front surface of the deep drawing mold, Raise the foil facing the front of the deep drawing die Driving a pressurizing device that generates a high pressure, pressing against the front surface of the deep drawing mold to give the foil a cross-sectional shape that matches the cross-sectional shape of the front surface of the deep drawing mold; Moving the foil given a given cross-sectional shape from the deep drawing portion, and separating the remaining portion of the foil from useful portions of the foil forming the diaphragm and having the given cross-sectional shape. A process for producing a diaphragm for an electro-acoustic transducer made of plastic and having a given cross-sectional shape, wherein the substantially flat foil has a deep drawing mold made of a sintered material. The air between the front surface of the deep drawing die and the foil facing the front surface is carried to a deep drawing part, and the air formed between the particles coalesced by sintering in the sintering material is The deep drawing die through no gap Wherein the discharged spent. 2. The useful portion of the foil forming the diaphragm and having the given cross-sectional shape, after the foil given the given cross-sectional shape has been moved from the deep drawing, comprises: The remaining portion of the foil is bonded to a metal ring surrounding the useful portion of the foil, and the separation of the remaining portion of the foil from the useful portion of the foil is along a radially extending isolation region outside the metal ring. The method of claim 1 wherein the method is performed. 3. The method according to claim 1, wherein the substantially flat foil is conveyed to a heating section before being conveyed to the deep drawing section and heated to a temperature within a given temperature range. . 4. The pressure applied by the driven pressurizing device to the foil facing the front side of the deep drawing mold is applied to a surface of the foil that coincides with the diaphragm back side of the diaphragm to be manufactured. The method of claim 1 wherein the method is performed. 5. A deep drawing in a given deep drawing direction, wherein the front surface has a cross-sectional shape corresponding to a given cross-sectional shape of the diaphragm, and the front surface is spaced from the front surface in the deep drawing direction. A deep drawing portion including a deep drawing die having a back surface; an arrangement means for transporting a substantially flat foil made of plastic to the deep drawing portion; Holding means for holding the foil, and suctioning the deep-drawing die in the region of the back surface of the deep-drawing die, and air between the front surface of the deep-drawing die and the foil facing the front surface. A vacuum generating device that generates a partial vacuum by discharging the deep drawing die from the front surface to the rear surface of the deep drawing die through the deep drawing die, and the foil facing the front surface of the deep drawing die. Press against the front side of the deep drawing mold A pressurizing device for generating a high pressure, pressing the foil against the front surface of the deep drawing mold, and giving the foil a cross-sectional shape corresponding to the cross-sectional shape of the front surface of the deep drawing mold; Disposing means for moving the foil having a given cross-sectional shape from the deep drawing portion, and separating a remaining portion of the foil from a useful portion of the foil having the given cross-sectional shape by forming the diaphragm. A manufacturing device for manufacturing a diaphragm for a biographic acoustic transducer having a given cross-sectional shape, the deep drawing portion comprising particles separated by sintering. A deep drawing die made of the sintered material having a gap without formed particles, wherein the air between the front surface of the deep drawing die and the foil facing the front surface is the deep drawing die; Be discharged through Device according to claim. 6. A joining means for carrying the foil having the given cross-sectional shape after moving from the deep drawing portion, and further carrying a metal ring, wherein the joining means forms the diaphragm and Joining the useful portion of the foil having a given cross-sectional shape to the metal ring such that the metal ring surrounds the useful portion of the foil; 6. The apparatus of claim 5, wherein the remaining portion of the foil is arranged to separate along a radially extending separation region outside the metal ring. 7. Apparatus according to claim 5, wherein a heating section is provided for transporting the substantially flat foil and heating it to a temperature within a given temperature range. 8. The deep drawing portion has a front surface having a cross-sectional shape corresponding to a cross-sectional shape of the diaphragm at a position of the front surface of the diaphragm, and has a deep drawing die formed of a sintered material. An apparatus according to claim 5, characterized in that: 9. It is made of plastic and has a given cross-sectional shape, characterized in that the at least one diaphragm surface is formed completely free of protrusions that are convex with respect to the diaphragm surface. A diaphragm for an electroacoustic transducer manufactured by deep drawing.