GB2094701A - Speaker diaphragm and method of manufacture - Google Patents
Speaker diaphragm and method of manufacture Download PDFInfo
- Publication number
- GB2094701A GB2094701A GB8203070A GB8203070A GB2094701A GB 2094701 A GB2094701 A GB 2094701A GB 8203070 A GB8203070 A GB 8203070A GB 8203070 A GB8203070 A GB 8203070A GB 2094701 A GB2094701 A GB 2094701A
- Authority
- GB
- United Kingdom
- Prior art keywords
- sheet
- diaphragm
- thermoplastic resin
- fiber
- cone portion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
- B29C51/14—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor using multilayered preforms or sheets
- B29C51/145—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor using multilayered preforms or sheets having at least one layer of textile or fibrous material combined with at least one plastics layer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
- B29C51/08—Deep drawing or matched-mould forming, i.e. using mechanical means only
- B29C51/082—Deep drawing or matched-mould forming, i.e. using mechanical means only by shaping between complementary mould parts
- B29C51/087—Deep drawing or matched-mould forming, i.e. using mechanical means only by shaping between complementary mould parts with at least one of the mould parts comprising independently movable sections
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R31/00—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor
- H04R31/003—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor for diaphragms or their outer suspension
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R7/00—Diaphragms for electromechanical transducers; Cones
- H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R7/00—Diaphragms for electromechanical transducers; Cones
- H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
- H04R7/12—Non-planar diaphragms or cones
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R7/00—Diaphragms for electromechanical transducers; Cones
- H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
- H04R7/12—Non-planar diaphragms or cones
- H04R7/122—Non-planar diaphragms or cones comprising a plurality of sections or layers
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
- B29C51/08—Deep drawing or matched-mould forming, i.e. using mechanical means only
- B29C51/082—Deep drawing or matched-mould forming, i.e. using mechanical means only by shaping between complementary mould parts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2031/00—Other particular articles
- B29L2031/755—Membranes, diaphragms
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2231/00—Details of apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor covered by H04R31/00, not provided for in its subgroups
- H04R2231/001—Moulding aspects of diaphragm or surround
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2231/00—Details of apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor covered by H04R31/00, not provided for in its subgroups
- H04R2231/003—Manufacturing aspects of the outer suspension of loudspeaker or microphone diaphragms or of their connecting aspects to said diaphragms
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2307/00—Details of diaphragms or cones for electromechanical transducers, their suspension or their manufacture covered by H04R7/00 or H04R31/003, not provided for in any of its subgroups
- H04R2307/025—Diaphragms comprising polymeric materials
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2307/00—Details of diaphragms or cones for electromechanical transducers, their suspension or their manufacture covered by H04R7/00 or H04R31/003, not provided for in any of its subgroups
- H04R2307/029—Diaphragms comprising fibres
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2307/00—Details of diaphragms or cones for electromechanical transducers, their suspension or their manufacture covered by H04R7/00 or H04R31/003, not provided for in any of its subgroups
- H04R2307/204—Material aspects of the outer suspension of loudspeaker diaphragms
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Multimedia (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Textile Engineering (AREA)
- Diaphragms For Electromechanical Transducers (AREA)
Abstract
A fixed type diaphragm for speaker and a method of producing such diaphragm comprising a sheet-forming step comprising forming a sheet for the edge portion composed principally of a thermoplastic resin fiber and mixed with a reinforcing material while also forming and laminating on the said sheet the circular sheets for the cone portion composed principally of a thermoplastic resin fiber and mixed with a reinforcing material; a cutting step in which the formed laminate sheet is cut; a heating step in which each cut sheet is held between heating plates and thereby heated and softened; and a molding step in which the heated and softened sheet is cold pressed by the top and bottom disc. In the preferred embodiment, a base sheet (10) carrying discs (11) is heat softened in the area of the discs by plats (12-1 5). The thus softened areas are then drawn to form diaphragms between a lower ferrule die (16) and a movable upper die (17') having a clamping ring (17''). The disc and ring are cooled. <IMAGE>
Description
SPECIFICATION
Diaphragm for speaker and method of producing same
This invention relates to a fixed-type speaker diaphragm in which the cone portion and the edge portion are formed integral with each other, and a method of producing such speaker diaphragm.
Generally, the diaphragms for speaker may be classified roughly into the following two types: a free edge type diaphragm in which the cone portion and the edge portion are made from the different materials and a fixed type diaphragm in which both cone portion and edge portion are formed as an integral structure. The free edge type diaphragm for speaker, because of use of different materials for the cone and edge portions, is typified by the good frequency characteristic of the diaphragm itself but on the other hand it has the demerits that many production steps are required and high-speed continuous production is difficult, resulting in a high production cost.The fixed type diaphragm is advantageous in respect of production cost as it is capable of high-speed continuous production, but it has the drawback in that it produces a sharp edge resonance and is poor in frequency characteristic because of formation of both cone and edge portions with the same material.
Heretofore, natural pulp has been used as the material of the fixed type speaker diaphragm, and it has been produced by processing said natural pulp into the speaker-shaped sheets piece by piece, or in the case of a two-layer laminate structure, by cutting a two-layer lamiante sheet into a fan shape, bonding the ends of the fan-shaped laminate sheet to form a cone, moistening the cone-shaped sheet and further thermoforming it in a moistened condition. Therefore, the fixed type speaker diaphragm, although easier to manufacture than the free edge type diaphragm, required much time for its fabrication and also wide scatter would result in quality from product to product.
The present inventors have pursued further studies for eliminating these defects of the conventionaml fixed type speaker diaphragm and succeeded in completing the present invention.
An object of this invention is to provide a fixed type speaker diaphragm with minimized edge resonance.
Another object of the invention is to provide a method for high-speed continuous production of the said fixed type speaker diaphragm.
The invention is described in detail hereinbelow.
The speaker diaphragm according to this invention features integral formation of both cone portion and edge portion by using synthetic pulp of a thermoplastic resin as base material, but different reinforcing materials are used for the cone and edge portions so that the edge portion will have a high internal loss characteristic while the cone portion will have a high modulus of elasticity. Owing to such feature, the speaker diaphragm of this invention is typified by minimized edge resonance and a flat frequency characteristic throughout the working frequency band.
As said reinforcing materials, there may be used inorganic fiber, organic fiber, natural fiber and the like. The term "synthetic pulp of a thermoplastic resin" as used herein refers to the fibrillated preparations of polyethylene fiber, polypropylene fiber, nylon fiber, polyester fiber and the like. The term inorganic fiber" refers to carbon fiber, glass fiber, alumina fiber, boron fiber and the like, and the term "organic fiber" refers to aramid fiber, polyester fiber, polypropylene fiber, acrylic fiber and composite fibers such as polyester-polyethylene terephthalate fiber. The term "natural fiber" is used herein to refer to wood pulp, cotton, wool and the like.
In the production of the speaker diaphragm according to this invention, it is advisable to impregnate the pulp with a thermoplastic emulsion or a thermoplastic resin solution for increasing the internal loss of the diaphragm while bettering moldability of the pulp at the time of continuous molding thereof. The said "thermoplastic emulsion" refers to an acrylic emulsion, an ethylene-vinyl acetate emulsion, an ethylene-vinyl acetate-vinyl chloride emulsion and the like, and said "thermoplastic resin solution" is exemplified by a vinyl acetate solution, a vinyl chloride solution, a polyamide solution, a polyurethane solution and the like.
The content of the synthetic pulp used as the base material in the diaphragm is preferably 50% by weight or more for the reason of good moldability, and it is also desirable that the basis weight of the edge portion is equal to or smaller than the basis weight of the cone portion. In most of the prior art devices, basis weight of the cone portion is about twice that of the edge portion. As the cone portion needs to have a high modulus of elasticity, it is necessary to use a fiber with a high modulus of elasticity as the reinforcing material for the cone portion, while the subsidiary material capable of inducing a large internal loss is used for the edge portion.
The diaphragm for speaker according to this invention is fabricated by continuously molding the two-layer laminate sheets.
Brief description of the drawings
Figure 1 is a schematic illustration of a sheetmaking apparatus.
Figure 2 is a sectional view of a circular screen used in the said apparatus.
Figure 3 (at to (E) are the drawings showing the production process of the speaker diaphragm in an embodiment of this invention.
Figure 4 is a sectional view of a speaker diaphragm obtained according to the method of this invention.
Figure 5 is a sectional view of another example of circular screen used in the sheet-making apparatus.
Figures 6 and 8 are the frequency characteristic diagrams of the speaker diaphragms according to
Examples 1 to 3 of this invention.
Figure 9 is a frequency characteristic diagram of a fixed type paper cone diaphragm.
Referring to Figure 1, there is shown a sheetmaking apparatus by a schematic drawing. In the drawing, numeral 1 indicates a tank containing the base material 2 for the edge portion. It will be seen that a circular screen 3 comprising a cylindrical net is rotatably supported in the tank 1.4 is a tank containing the base material 5 for the cone portion.
A circular screen 6 composed of a cylindrical net is rotatably supported in the said tank 4. The said circular screen 6 is provided at its outer periphery with a mask 8 having a thickness of approximately 200 microns and formed with circular holes 7 as shown in Figure 2. In Figure 1, numeral 9 refers to a cotton cloth which travels in the direction of arrows while guided by the rolls.
In operation of the apparatus of Figure 1,the material 2 for the edge portion deposits on the outer peripheral surface of the rotating cylindrical screen net 3 and the said material 2 further adheres to the underside of the travelling cotton cloth 9, thus forming a sheet of the said material 2 on the cotton cloth 9. In the meantime, the material 5 for the cone portion adheres to the hole parts 7 of the mask 8 on the outer peripheral surface of another rotating circular screen 6, and the thereby formed circular sheets are attached onto the above-said sheet for the edge portion.
Figure 3(A) shows a sheet formed by the said sheet-making apparatus. In the drawing, numeral 10 denotes the sheet made from the material 2 for the edge portion, and 11 indicates the circular sheets made from the material 5 for the cone portion, said sheets 11 being attached on the elongated sheet 10.
Numeral 10' designates a guideline made from the same material as the circular sheets 11 and formed simultaneously with formation of said circular sheets 11.
Again referring to Figure 1, numerals 20 and 21 indicate the couch rolls for sucking water in the respective formed sheets 10 and 11, 22 a water suction device and 23 the squeeze rolls. Said sheets 10 and 11 are thereby dehydrated, and then the sheet laminate is further dried by a dryer 24 and taken up.
The laminate sheet made by the said sheet-making apparatus comprises a plurality of circular sheets 11 for cone portion bonded and arrayed in four rows on a sheet 10 for edge portion as shown in Figure 3 (A), and the said laminate sheet is cut by a slitter having a photodetector as shown in Figure 3(B). When the sheet shown in Figure 3(A) is carried forward, said sheet moves in a zigzag direction, but in this embodiment of the invention, since the guideline 10' is detected by the photodetector and sheet cutting is performed in conformity to the meandering of the sheet, there can be accomplished correct cutting as shown in Figure 3(B). The guideline may be provided either at the center or along an end or ends of the sheet, and the guide range may be 5 to 10 mm.
Figure 3(C) shows the heating step. In Figure 3(C), numerals 12 and 12' denote the heating plates the surfaces of which are coated with Teflon 13, 13'.
Numerals 14 and 14' indicate the heaters disposed at the center of said respective heating plates 12 and 12', and numerals 15 and 15' refer to the water pipes arranged annularly along the peripheries of said respective heating plates 12 and 12'. Said heating plates 12 and 12' are high in temperature at the center and low in temperature toward the periphery and a designed to hold and heat the sheets 10 and 11 therebetween. Being basically composed of a thermoplastic resin fiber, said both sheets 10 and 11 are softened as they are heated by the heating plates 12 and 12'. All of said sheets 10 and 11 are uniformly softened because the surface temperature of said heating plates 12 and 12' is so distributed that it is higher at the center and lower at the peripheral portion in conformity to the thickness of the sheets 10 and 11.
Figure 3(D) illustrates the molding step. In Figure 3(D), numeral 16 designates the bottom force and numeral 17 the top force. The top force 17 consists of a central segment 17' corresponding to the cone portion and a cylindrical peripheral segment 17" supported slidably around said central segment 17'.
Numeral 18 indicates springs adapted for forcing the peripheral segment 17" downwardly. Such springs may be omitted. As shown in Figure 3(D), the heated and softened sheets 10 and 11 move to the position between the top and bottom forces 17 and 16 and held therebetween. In this operation, first the part of the sheet 10 corresponding to the edge portion is held between the peripheral top force segment 17" and the bottom force 16 and then the remaining part of the sheet 10 and the sheet 11 are held by the central top force segment 17' and the bottom force 16. As the softened sheets 10 and 11 are thus cold pressed, the whole laminate sheet is cone-shaped as shown in Figure 3(E).
In the molding step illustrated in Figure 3(D), there may be used a top force in which both cone portion and edge portion are formed as a unitary structure, but in this case, since the cone portion of the top force first contacts the sheets 10 and 11 in the pressing operation, the cone portion of said sheets 10 and 11 is stretched to form, in some cases, wrinkles in the sheet. On the other hand, if the top force 17 is composed of the separate central and peripheral segments as shown in Figure 3(D) and the pressing operation is conducted by first holding the edge portion of the sheets 10, 11 and then holding the cone portion as said above, there is no fear of producing wrinkles in the sheet. It is to be also noted that a hole 19 is formed at the center of the central top force segment 17' as shown in Figure 3(D). This hole is intended to serve as an air vent for preventing the molded sheet from being raised up with the top force 17 and thereby deformed when the top force ascends after the pressing operation.
The first and second layers in the cone portion are almost firmly bonded in the course of making of the elongated sheet, but they are further heat-bonded and integrated at the time of heating and molding to give a high peel stength.
Figure 4 shows a molded diaphragm unit as cut out from the sheet 10. As seen from the drawing, the edge portion is formed from the sheet 10 alone while the cone portion is composed of a laminate structure consisting of the sheets 10 and 11. The central flat part of the cone portion in Figure 4 is cut out to obtain a completed diaphragm for speaker.
The method of this invention featuring the above described steps can produce the following salient effects.
(1) Because of use of a laminate sheet consisting of a sheet for edge portion and circular sheets for cone portion bonded thereon and also because of use of a thermoplastic resin fiber as the base material of both sheets, it is possible to produce the desired diaphragms continuously and at high speed by continuously passing the said laminate sheet through the heating and cold pressing steps.
(2) There is no fear of forming wrinkles in the sheet as the top force of the die used for cold pressing is constructed from two separate segments, that is, a central segmentcorresponding to the cone portion and a peripheral segment corresponding to the edge portion and, in operation, the part of the sheet corresponding to the edge portion is first held and then the part corresponding to the cone portion is held.
(3) In case a hole for air vent is provided in the central segment of the top force, the molded sheet would not be raised up with the top force when it ascends after the pressing operation, and hence there is no possibility of causing sheet deformation.
(4) In case of using the heating plates provided with a heater at the center and a water pipe around the periphery, it is possible to attain uniform softening of both cone portion and edge portion which differ in thickness from each other.
(5) By forming a guideline concurrently with formation of the laminate sheet consisting of an edge sheet and circular cone sheets laid thereon in the sheet-making step, it is possible to detect meandering of the sheet by using the said guideline as a reference line, allowing correct cutting of the sheet.
A problem was involved in formation of a twolayer laminate sheet by use of the said type of sheet-making apparatus, that is, the peripheral parts of the circular sheets 11 bonded on the sheet 10 would become irregular due to adhesion of the material 5 for cone portion even to the edges of the holes 7 in the mask 8, resulting in a poor boundary precision of the cone portion and a wide change of the minimum resonance frequency fo of the speaker or occurrence of an abnormally high edge resonance in the medium frequency band to cause increased distortion in the said band. In this invention, in order to better the boundary precision of the cone portion and to allowthe circular sheets 11 to have a perfect roundness, it is recommended to use a circular screen net 6' such as shown in Figure 5.The mask 8' having the holes 7' and provided around the periphery of the said circular screen 6' is made from an elastic material such as foamed rubber. When this circular screen 6' is used, since the thickness of the mask 8' is greater than that of the mask used in the conventional circular screen 6, the material 5 for the cone portion deposits only in the holes 7' of the circular screen 6' and the thickness of the mask 8' becomes greater by more than 1 mm than the sheet-forming thickness of the material 5.As the said circular screen 6' turns and is pressed underthe couch roll 21,the mask 8' made from an elastic material is compressed and its thickness becomes substantially equal to the thickness of the material 5 formed into a sheet in each said hole 7', and the thus formed circular sheets of the material 5 adhere to the sheet 10 carried on the travelling cotton cloth 9.
Thus, when the mask 8' of a foamed elastic material is used, the sheet-forming range of the material 5 for cone portion is restricted within the holes 7' in the mask 8', so that the boundary precision between the cone portion and edge portion is held within j1 mm, allowing formation of the sheets for cone portion with almost perfect roundness.
For further explaining the fixed type diaphragm for speaker according to this invention, there are shown hereinbelow the embodiments of this invention, but it is to be understood that the present invention is not limited to these embodiments.
Example 1
Used as base material was fibriliated high-density polyethylene fiber adjusted to a heating degree of 190 ml (Canadian Standard Freeness) by a disc refiner. The first layer forming the edge portion was composed of said high-density polyethylene fiber (80% by weight) and aramid fiber (20% by weight) having a fiber length of 2 mm and had a basis weight of 45 g/m2. The second layer forming the cone portion was composed of said high-density polyethylene fiber (85% by weight) and carbon fiber (15% by weight) with a fiber length of 3 mm and had a basis weight of 50 g/m2. An elongated sheet was produced by using the circular-screen sheet-making machine shown in Figure 1.The mask used for the circular screen for the secmond layer was formed from 3 mmthickfoamed chloroprene rubber, and the couch roll was operated in a dehydratable state.
The formed elongated sheet was such as shown in
Figure 3. The diameter of each cone portion was 75 mm and the interval between every adjoining cone portions was 135 mm.
This elongated sheet was slitted according to the process shown in Figure 3, then heated and softened and then molded by cold press. The die temperature was adjusted to 2009C at the center of the die and 150"C at the periphery. The heating time was 5 seconds and the molding time was 2 seconds. There was employed a molding method in which the edge portion was first molded and then the cone portion was molded. The molded diaphragm had a configuration such as shown in Figure 4 and showed the frequency characteristic graphically shown in Figure 6.
Example 2
The elongated sheet made in Example 1 was impregnated with an ethylene (80%)-vinyl acetate (20%) emulsion to a pickup of 10 g/m2 by using an ordinary impregnating apparatus and dried at a temperature of 90 C. The thus treated elongated sheet was cut, heated and molded according to the method of Example 1 to produce a diaphragm of the same configuration as that of Example 1. The frequency characteristic of this diaphragm was as graphically shown in Figure 7.
Example 3
The base material was same as used in Example 1.
The first layer for forming the edge portion was composed of the base material (70% by weight) and 6 mm-long polyester fiber (30% by weight) and had a basis weight of 50 git2, while the cone portion was composed of the base material (70% by weight), 2 mm-long aramid fiber (15% by weight) and 6 mm-long glass fiber (5% by weight), with the basis weight being adjusted to 50 g/m2. An elongated sheet was formed from said materials and subjected to the completely same molding operation as in
Example 1 to make a diaphragm of the same configuration as that of Example 1. The frequency characteristic of this diaphragm is shown in Figure 8.
Each of the diaphragms of Examples 1 to 3 was assembled into a speaker by using necessary jigs and their frequency characteristic was measured by using JIS-BOX. Figure 9 shows the frequency characteristic of an ordinary fixed type paper cone by way of a comparative data.
Claims (14)
1. A method of producing a diaphragm for speaker, which comprises a sheet-forming step comprising forming a sheet for edge portion com
posed principally of a thermoplastic resin fiber and
mixed with a reinforcing material and further forming a laminating on said sheet the circular sheets for cone portion composed principally of a thermoplastic resin fiber and mixed with a reinforcing material; a cutting step in which the said laminate sheet is cut;
a heating step in which each cut laminate sheet is
held between the heating plates and thereby heated
and softened; and a molding step in which the
heated and softened sheet is cold pressed by the top
and bottom forces.
The method of producing a diaphragm for speaker
according to Claim 1, characterized by using a top force constituted from a central segment and a
cylindrical peripheral segment slidably supported
around said central segment.
3. The method of producing a diaphragm for
speaker according to Claim 2, characterized in that
an air vent hole is provided in the central top force
segment.
4. The method of producing a diaphragm for
speaker according to Claim 1, featuring use of the
heating plates each of which is provided with a
heater at the center and a water pipe along the
periphery.
5. The method of producing a diaphragm for
speaker according to Claim 1, wherein a guideline is formed concurrently with formation of the laminate
sheet.
6. The method of producing a diaphragm for
speaker according to Claim 5, wherein when cutting
the laminate sheet, the guideline is detected and the
sheet is cut along the said guideline.
7. The method of producing a diaphragm for
speaker accordng to Claim 1, wherein the laminate
sheet is formed by making a sheet for edge portion
by using a first circular screen net while making the
sheets for cone portion by using a second circular screen net having provided therearound a mask made of an elastic material and formed with the holes, and then compressing said mask to let said sheets for cone portion adhere onto the sheet for edge portion.
8. A fixed type diaphragm for speaker in which the cone portion and the edge portion are formed integral with each other, characterized in that both edge portion and cone portion are formed from a composite fiber sheet composed principally of synthetic pulp of a thermoplastic resin and mixed with a reinforcing material, but the edge portion has a smaller basis weight than the cone portion and also has a high internal loss characteristic and the cone portion has the characteristic of high modulus of elasticity.
9. The diaphragm for speaker according to Claim 8, wherein the sheet is composed of composite fiber comprising synthetic pulp of a thermoplastic resin as base material and at least one of inorganic fiber, organic fiber and natural fiber as reinforcing material.
10. The diaphragm for speaker according to
Claim 8, wherein the edge portion is made from composite fiber composed principally of synthetic pulp of a thermoplastic resin and mixed with a reinforcing material with a high internal loss characteristic, and the cone portion is made from a laminate of the same composite fiber as used for the edge portion and another composite fiber composed principally of synthetic pulp of a thermoplastic resin and mixed with a reinforcing material with a high modulus of elasticity.
11. The diaphragm for speaker according to
Claim 10, wherein the edge protion is made from composite fiber composed of synthetic pulp of a thermoplastic resin and aramid fiber, and the cone portion is made from a two-layer laminate of composite fiber composed of synthetic pulp of a thermoplastic resin and carbon fiber and another composite fiber composed of synthetic pulp of a thermoplastic resin and aramid fiber.
12. The diaphragm for speaker according to
Claim 10, wherein the edge portion is made from composite fiber composed of synthetic pulp of a thermoplastic resin and acrylic fiber, and the cone portion is made from a two-layer laminate of composite fiber composed of synthetic pulp of a thermoplastic resin, aramid fiber and wood pulp and another composite fiber composed of synthetic pulp of a thermoplastic resin and acrylic fiber.
13. The diaphragm for speaker according to
Claim 8, wherein the sheet is impregnated with a thermoplastic resin emulsion or a thermoplastic resin solution.
14. The diaphragm for speaker according to
Claim 13, wherein an ethylene-vinyl acetate emulsion is used as the sheet-impregnating thermoplastic resin emulsion.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1666981A JPS57131198A (en) | 1981-02-05 | 1981-02-05 | Manufacture of diaphragm for loudspeaker |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2094701A true GB2094701A (en) | 1982-09-22 |
Family
ID=11922720
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8203070A Withdrawn GB2094701A (en) | 1981-02-05 | 1982-02-03 | Speaker diaphragm and method of manufacture |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS57131198A (en) |
| DE (1) | DE3203285A1 (en) |
| GB (1) | GB2094701A (en) |
Cited By (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0251057A1 (en) * | 1986-06-21 | 1988-01-07 | EWD Electronic-Werke Deutschland GmbH | Loudspeaker |
| FR2611577A1 (en) * | 1987-03-06 | 1988-09-09 | Renault | METHOD FOR CONFORMING SYNTHETIC ELEMENTS, SUCH AS BODY PARTS FOR A MOTOR VEHICLE |
| EP0508596A1 (en) * | 1991-03-29 | 1992-10-14 | Bose Corporation | Electroacoustical transducer |
| EP0632675A1 (en) * | 1993-06-28 | 1995-01-04 | Matsushita Electric Industrial Co., Ltd. | Diaphragm-edge integral moldings for speakers, acoustic transducers comprising same and method for fabricating same |
| EP0714752A2 (en) * | 1994-12-02 | 1996-06-05 | Miguel Alives Porta | A process and arrangement for three dimensional forming of a fabric |
| EP0783238A3 (en) * | 1995-12-22 | 1998-07-01 | S.I.P.E. Società Italiana Prodotti Elettromeccanici - S.p.A. | Method for the production and application of annular suspension edges of lound speaker diaphragms |
| EP1039355A1 (en) * | 1999-03-24 | 2000-09-27 | Eta SA Fabriques d'Ebauches | Process for manufacturing indicator organs and indicator organ manufactured accordingly |
| WO2000058073A1 (en) * | 1999-03-25 | 2000-10-05 | Koninklijke Philips Electronics N.V. | Method of and arrangement for manufacturing a plastic diaphragm for an electroacoustic transducer |
| US6668456B1 (en) | 1999-03-24 | 2003-12-30 | Eta Sa Fabriques D'ebauches | Method for manufacturing a display element for a timepiece and display element manufactured in accordance with such method |
| WO2005055657A1 (en) * | 2003-12-08 | 2005-06-16 | Bujeon Components., Ltd. | Method and apparatus for manufacturing vibrator for electro-acoustic transducers, vibrator manufactured by the same, and electro-acoustic transducer having the vibrator |
| EP2268059A1 (en) * | 2009-06-26 | 2010-12-29 | Canon Kabushiki Kaisha | Radiating unit for loudspeaker |
| CN101207944B (en) * | 2006-12-18 | 2011-05-11 | 深圳市豪恩声学股份有限公司 | Method for manufacturing microphone diaphragm |
| WO2013060811A1 (en) * | 2011-10-29 | 2013-05-02 | Kraussmaffei Technologies Gmbh | Process for producing plastic molded pieces |
| CN103347243A (en) * | 2013-06-08 | 2013-10-09 | 歌尔声学股份有限公司 | Integrated manufacturing method for vibrating diaphragm and gasket for microphone |
| CN109968684A (en) * | 2019-03-13 | 2019-07-05 | 东莞涌韵音膜有限公司 | The manufacture craft of the compound ring of liquid |
| CN113709634A (en) * | 2020-05-20 | 2021-11-26 | 歌尔股份有限公司 | Vibrating plate and sound generating device |
| CN113709633A (en) * | 2020-05-20 | 2021-11-26 | 歌尔股份有限公司 | Vibrating plate and sound generating device |
| CN113709636A (en) * | 2020-05-20 | 2021-11-26 | 歌尔股份有限公司 | Vibrating plate and sound generating device |
| CN113709635A (en) * | 2020-05-20 | 2021-11-26 | 歌尔股份有限公司 | Vibrating plate and sound generating device |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008060054A1 (en) | 2008-12-02 | 2010-06-10 | Panasonic Corporation, Kadoma-shi | Loudspeaker, has loudspeaker diaphragm comprising edge directly connected to loudspeaker frame, bellows formed in edge region of diaphragm, and damping elements arranged in folding of bellows |
| CN114654705B (en) * | 2022-02-18 | 2023-09-15 | 成都领益科技有限公司 | Hot press molding process, speaker mesh enclosure and earphone |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5423568B2 (en) * | 1971-11-22 | 1979-08-15 | ||
| JPS53135321A (en) * | 1977-04-28 | 1978-11-25 | Sony Corp | Production of diaphragm for speakers |
-
1981
- 1981-02-05 JP JP1666981A patent/JPS57131198A/en active Pending
-
1982
- 1982-02-01 DE DE19823203285 patent/DE3203285A1/en not_active Withdrawn
- 1982-02-03 GB GB8203070A patent/GB2094701A/en not_active Withdrawn
Cited By (31)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0251057A1 (en) * | 1986-06-21 | 1988-01-07 | EWD Electronic-Werke Deutschland GmbH | Loudspeaker |
| FR2611577A1 (en) * | 1987-03-06 | 1988-09-09 | Renault | METHOD FOR CONFORMING SYNTHETIC ELEMENTS, SUCH AS BODY PARTS FOR A MOTOR VEHICLE |
| EP0283378A2 (en) * | 1987-03-06 | 1988-09-21 | Regie Nationale Des Usines Renault | Method of moulding parts of synthetic material such as automobile body panels, and apparatus for carrying out said method |
| EP0283378A3 (en) * | 1987-03-06 | 1988-10-12 | Regie Nationale Des Usines Renault | Method of moulding parts of synthetic material such as automobile body panels, and apparatus for carrying out said method |
| EP0508596A1 (en) * | 1991-03-29 | 1992-10-14 | Bose Corporation | Electroacoustical transducer |
| EP0632675A1 (en) * | 1993-06-28 | 1995-01-04 | Matsushita Electric Industrial Co., Ltd. | Diaphragm-edge integral moldings for speakers, acoustic transducers comprising same and method for fabricating same |
| US5744761A (en) * | 1993-06-28 | 1998-04-28 | Matsushita Electric Industrial Co., Ltd. | Diaphragm-edge integral moldings for speakers and acoustic transducers comprising same |
| US6039145A (en) * | 1993-06-28 | 2000-03-21 | Matsushita Electric Industial Co., Ltd. | Diaphragm-edge integral moldings for speakers, acoustic transducers comprising same and method for fabricating same |
| EP0714752A2 (en) * | 1994-12-02 | 1996-06-05 | Miguel Alives Porta | A process and arrangement for three dimensional forming of a fabric |
| EP0714752A3 (en) * | 1994-12-02 | 1997-10-08 | Porta Miguel Alives | A process and arrangement for three dimensional forming of a fabric |
| US5783137A (en) * | 1994-12-02 | 1998-07-21 | Alives Porta; Miguel | Process for three dimensional forming of a fabric |
| EP0783238A3 (en) * | 1995-12-22 | 1998-07-01 | S.I.P.E. Società Italiana Prodotti Elettromeccanici - S.p.A. | Method for the production and application of annular suspension edges of lound speaker diaphragms |
| US6668456B1 (en) | 1999-03-24 | 2003-12-30 | Eta Sa Fabriques D'ebauches | Method for manufacturing a display element for a timepiece and display element manufactured in accordance with such method |
| EP1039355A1 (en) * | 1999-03-24 | 2000-09-27 | Eta SA Fabriques d'Ebauches | Process for manufacturing indicator organs and indicator organ manufactured accordingly |
| WO2000058073A1 (en) * | 1999-03-25 | 2000-10-05 | Koninklijke Philips Electronics N.V. | Method of and arrangement for manufacturing a plastic diaphragm for an electroacoustic transducer |
| WO2005055657A1 (en) * | 2003-12-08 | 2005-06-16 | Bujeon Components., Ltd. | Method and apparatus for manufacturing vibrator for electro-acoustic transducers, vibrator manufactured by the same, and electro-acoustic transducer having the vibrator |
| CN101207944B (en) * | 2006-12-18 | 2011-05-11 | 深圳市豪恩声学股份有限公司 | Method for manufacturing microphone diaphragm |
| EP2268059A1 (en) * | 2009-06-26 | 2010-12-29 | Canon Kabushiki Kaisha | Radiating unit for loudspeaker |
| WO2013060811A1 (en) * | 2011-10-29 | 2013-05-02 | Kraussmaffei Technologies Gmbh | Process for producing plastic molded pieces |
| CN104254434A (en) * | 2011-10-29 | 2014-12-31 | 克劳斯玛菲科技有限公司 | Process for producing plastic molded pieces |
| CN103347243A (en) * | 2013-06-08 | 2013-10-09 | 歌尔声学股份有限公司 | Integrated manufacturing method for vibrating diaphragm and gasket for microphone |
| CN109968684A (en) * | 2019-03-13 | 2019-07-05 | 东莞涌韵音膜有限公司 | The manufacture craft of the compound ring of liquid |
| CN109968684B (en) * | 2019-03-13 | 2021-06-08 | 东莞涌韵音膜有限公司 | Manufacturing process of liquid composite folding ring |
| CN113709634A (en) * | 2020-05-20 | 2021-11-26 | 歌尔股份有限公司 | Vibrating plate and sound generating device |
| CN113709633A (en) * | 2020-05-20 | 2021-11-26 | 歌尔股份有限公司 | Vibrating plate and sound generating device |
| CN113709636A (en) * | 2020-05-20 | 2021-11-26 | 歌尔股份有限公司 | Vibrating plate and sound generating device |
| CN113709635A (en) * | 2020-05-20 | 2021-11-26 | 歌尔股份有限公司 | Vibrating plate and sound generating device |
| CN113709636B (en) * | 2020-05-20 | 2023-11-17 | 歌尔股份有限公司 | Vibrating plate and sound producing device |
| CN113709634B (en) * | 2020-05-20 | 2023-11-17 | 歌尔股份有限公司 | Vibrating plate and sound producing device |
| CN113709633B (en) * | 2020-05-20 | 2023-11-17 | 歌尔股份有限公司 | Vibrating plate and sound producing device |
| CN113709635B (en) * | 2020-05-20 | 2024-04-09 | 歌尔股份有限公司 | Vibrating plate and sound producing device |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3203285A1 (en) | 1982-11-25 |
| JPS57131198A (en) | 1982-08-13 |
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Legal Events
| Date | Code | Title | Description |
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| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |