JPH0441880B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing a soft outer shell for a custom-shaped hearing aid, and more specifically, the invention relates to a method for manufacturing a soft outer shell for a custom-shaped hearing aid. The present invention relates to a method of manufacturing a soft outer shell for a custom-shaped hearing aid for forming a so-called custom-shaped hearing aid.

Ear molds include those that combine the ear shell and external auditory canal, and those that include only the external auditory canal. A custom-shaped hearing aid made from an ear mold of only the ear canal is particularly called a canal-shaped hearing aid.

[Prior Art] A conventional method for manufacturing a soft outer shell for a custom hearing aid will be described with reference to FIGS. 13 to 22. Figures 13 to 15 show an ear mold 1 in which a liquid synthetic resin such as silicone resin is injected into the consumer's ear shell and ear canal, and after hardening, it is taken out and unnecessary parts removed, and it fits the ear shell. It consists of a base 1a that fits into the external auditory canal and a protrusion 1b that fits into the external auditory canal.

Custom-shaped hearing aids have the following ear shape 1 and external shape,
A shell of the same size is made, and a microphone, amplifier, battery, volume control, earphones, etc. are housed inside this shell.
It is a complete hearing aid exclusively for individuals with hearing loss. The shell is made of a suitable soft material from the viewpoint of comfort when wearing the hearing aid and acoustic characteristics that do not generate howling.

Conventionally, in order to manufacture such a soft shell, first, as shown in FIGS. 16 and 17, a protrusion 2a that guides the ring 3 is attached to the outer periphery of the metal base 2.
is formed, the ring 3 is placed on the pedestal 2,
An ear mold 1 is placed in the center of the ring 3, and plaster 4, which is a molding material, is poured into the space around it. Next, after the plaster 4 has solidified, the pedestal 2 is removed and the ear mold 1 is taken out, as shown in FIG. 18, to create a female mold 6 in which a cavity 5 of the same shape and size as the ear mold 1 is formed. .

Next, as shown in FIG. 19, a metal upper mold 8 that fits into the ring 3 and has a gate 7 for injection molding in the center is placed on the ring 3, and is made of a soft resin such as vinyl chloride. By injection molding, a soft resin mold 9 as shown in FIG. 20 is completed. Next, as shown in FIGS. 21 and 22, the mold 9 is manually cut using a tool such as a cutter or drill so that the thickness of the outer wall 10 is approximately constant in the range of 1 to 2 mm. The soft shell 12 is completed by carving out the internal flesh and carving out a storage chamber 11 in which a microphone, amplifier, battery, volume control, earphones, etc. are housed.

[Problems to be Solved by the Invention] In the conventional manufacturing method of the soft outer shell for a custom-shaped hearing aid as described above, the mold 9 is manually molded with tools such as a cutter or a drill to create a uniform wall thickness. Carving and forming the storage chamber 11 in such a manner is an extremely difficult task and requires a great deal of skill and man-hours.

This invention was made to solve these problems, and provides a custom-shaped soft outer shell for hearing aids that eliminates the manual work of carving and forming the storage chamber and allows the soft shell to be manufactured easily and in a short time. The purpose is to learn how to make the body.

[Means for Solving the Problems] A method for manufacturing a custom-shaped soft outer shell for a hearing aid according to the present invention includes a cylindrical lower frame and an upper frame that fit together coaxially and do not rotate with each other. After preparing the mold and forming a cavity corresponding to the ear mold in the lower frame to obtain a female mold, a wall made of a thermofusible material with a thickness equivalent to the thickness of the outer shell is formed on the inner wall surface of the cavity. death,
The knob is integrated inside this wall to form an intermediate body made of resin, and then the upper frame is fitted to the lower frame, and the upper frame is filled with molding material and solidified, and then the upper frame is formed into the intermediate body. At the same time, it is separated from the lower frame, and a gate for resin injection molding is formed on the molding material to obtain a male mold. lastly,
The male mold and the female mold from which the wall has been removed are fitted together, and a soft resin is injected into the gap between the inner wall of the cavity and the intermediate body.

[Function] In the present invention, a soft outer shell having a predetermined shape and thickness is completed with a soft resin molded product that is injection molded into the gap between the female mold cavity inner wall and the male intermediate body.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 12.

First, as shown in FIG. 2, a lower frame 21 and an upper frame 22 made of metal and having substantially the same inner diameter as the ring 3 described above are prepared. The lower frame 21 and the upper frame 22 are fitted with each other at a stepped portion 2 so as to coaxially fit into each other to form a cylinder.
3 is formed, and a protrusion 2 is provided on the upper side of the lower frame 21 to prevent rotational displacement relative to each other.
4, and a recess 25 that engages with the protrusion 24 is formed on the lower side of the upper frame 22.

Next, as shown in FIG. 3, the lower frame 21 is placed on a flat plate with the stepped portion 23 facing down, and the ear mold 1 taken in the same manner as in the conventional method is placed in the center of the lower frame 21. Place 26 pieces of plaster around the ear mold 1 as a molding material.
Pour in and let it harden. Thereafter, when the ear mold 1 is removed, a female mold 28 having a cavity 27 corresponding to the ear mold 1 as shown in FIG. 4 is obtained.

Next, as shown in FIG. 5, melted paraffin 29 is poured into the cavity 27 of the female mold 28. This melted paraffin 29 is applied to the female mold 2.
8 absorbs heat and solidification starts from the periphery, so when solidification has progressed appropriately, the molten paraffin that has not yet solidified is poured out. Then, as shown in FIG. 6, a paraffin wall 30 of substantially uniform thickness remains on the inner wall surface of the cavity 27. Note that, as long as it exhibits similar properties, it is not limited to paraffin, and other heat-melting materials such as wax may be used.

After this, as shown in FIG. 7, an intermediate 31 made of a resin that remains appropriately flexible and elastic even after curing, such as semi-kneaded room temperature curing silicone rubber.
is filled inside the paraffin wall 30. At this time, a knob 32 for later pulling out the intermediate body 31 from the female mold 28 is formed, and the entire resin 31 is cured.

Next, as shown in FIG. 8, the upper frame 22 is fitted onto the lower frame 21. Then, since the upper half of the intermediate body 31 exists inside the upper frame 22, plaster 33 is poured as a molding material into the surrounding space and solidified. After the plaster 33 has sufficiently hardened, the lower frame 2
1 and the upper frame 22, the plaster 3 is removed within the upper frame 22.
3 and the knob 32 are engaged, so the intermediate body 3
1, as shown in FIGS. 9 and 10, the upper frame 22
It is pulled out to the side, and a male material 34 is completed. At this time, the lower frame 21 is in the state shown in FIG.

As the intermediate body 31, silicone rubber, etc.
The reason for using a resin material that remains soft and elastic to some extent even after curing is that it has a reverse slope in the direction of pulling it out from the female die 28, and it is difficult to pull out the intermediate body 31 from the paraffin wall 30, which has a complicated shape. This is to make it easier.

Next, the eleventh
As shown in FIG. 12, a small hole with a diameter of about 3 mm is drilled through the upper and lower sides to form a male mold 36 as a gate 35 for resin injection molding. On the other hand, the paraffin wall 30 of the female mold 28 shown in FIG. 6 is removed by heating and melting in a furnace, and the female mold 28 is returned to the state shown in FIG. 4.

Finally, the female mold 28 and the male mold 36 in the above state
and are fitted together as shown in FIG. Then, a gap corresponding to the paraffin wall 30 is created between the inner wall of the cavity 27 and the outer surface of the intermediate body 31, so when a soft resin such as soft vinyl chloride is injected into this gap from the gate 35, the paraffin A molded product 37 having the same shape and size as the wall 30 can be obtained. This molded product 37 is a desired soft shell corresponding to the ear mold 1.

Although the above description has been made of a soft shell that fits the ear shell and the ear canal, it is easy to understand that even a soft shell that fits only the ear canal in a canal-shaped hearing aid can be manufactured using the same method.

[Effect of the invention] As is clear from the above description, the invention has the following effects:
A cavity corresponding to the ear mold is formed in the lower frame to obtain a female mold, an intermediate body is formed inside the wall made of a thermofusible material of a predetermined thickness formed on the inner wall surface of the cavity, and the intermediate body is placed on the upper frame side. After that, the male mold and the female mold with the wall removed are fitted together and a soft resin is injected into the gap between the cavity inner wall and the intermediate body to complete the soft shell. A predetermined soft shell can be easily obtained without the need for machining with tools, and skilled manual labor is not required and the working time can be shortened.

[Brief explanation of drawings]

Figures 1 to 12 are for explaining one embodiment of the present invention. Figure 1 is a front cross-sectional view for explaining the final process, and Figure 2 is a part showing the lower frame and upper frame. 3 to 9 and 11 are front sectional views showing the process order, and FIGS. 10 and 12 are bottom views of FIGS. 9 and 11, respectively. 13 to 22 are for explaining a conventional method of manufacturing a soft shell for a custom-shaped hearing aid, and FIGS. 13 to 15 are a perspective view, a front view, and a plan view of an ear mold, respectively; 16, 18, and 19 are front sectional views showing the process order, FIG. 17 is a plan view of the one in FIG. 16, and FIG.
The figures are a front cross-sectional view of the molded product, Figure 21 and Figure 2.
Figure 2 is a plan view and a front sectional view showing the finished state of the shell. 1...Ear shape, 21...Lower frame, 22...Upper frame, 2
7...Cavity, 28...Female mold, 30...Paraffin (heat-melting material) wall, 31...Intermediate,
32...Knob part, 33...Gypsum (molding material), 3
5...gate, 36...male mold, 37...molded product.

Claims (1)

[Scope of Claims] 1. A step of preparing a cylindrical lower frame and an upper frame that are coaxially fitted with each other to suppress relative rotational displacement, and forming a cavity corresponding to an ear shape in the lower frame. forming a wall of a predetermined thickness made of a thermofusible material on the inner wall surface of the cavity; integrating a knob at the top inside the wall;
forming an intermediate made of resin; fitting the upper frame onto the lower frame; filling and solidifying a molding material in the upper frame; and then pulling the upper frame together with the intermediate from the lower frame; and further forming a gate for resin injection molding on the molding material to obtain a male mold, and fitting the male mold and the female mold from which the wall has been removed so that the inner wall of the cavity and the A method for manufacturing a custom-shaped soft outer shell for a hearing aid, comprising the steps of: molding a molded article made of soft resin in a gap with an intermediate body; 2. The method of manufacturing a soft outer shell for a custom-shaped hearing aid according to claim 1, wherein the soft resin is soft vinyl chloride. 3. The method of manufacturing a soft outer shell for a custom-shaped hearing aid according to claim 1, wherein the intermediate body is made of a flexible and elastic resin material. 4. The method for manufacturing a custom-shaped soft outer shell for a hearing aid according to claim 3, wherein the intermediate body is made of silicone rubber. 5. The method for manufacturing a custom-shaped soft outer shell for a hearing aid according to claim 1, wherein the thermofusible material is either paraffin or wax. 6. The method for manufacturing a custom-shaped soft outer shell for a hearing aid according to claim 1, wherein the molding material is gypsum.