JPS585559B2 - speaker horn - Google Patents

Description

[Detailed Description of the Invention] This invention has a flexible foam base that is reacted and foamed in a mold to hold a male screw body, and the foamed portion is impregnated with a hardening resin to form a retaining shape. The present invention also relates to a method of manufacturing a speaker horn in which the male screw body is removed.

Conventional speaker horns are often constructed from a single cast metal material.

Therefore, the sand mold used for casting had to be made for each casting and destroyed when removed after casting.
This was the main cause of the high cost of the horn.

Furthermore, it is difficult to partially change the state due to its integral structure.

The method for manufacturing a speaker horn of the present invention includes, for example,
A raw material for a synthetic resin material, such as urethane foam, which reacts at high temperatures, foams, and is flexible at room temperature, is placed in the mold 1.
, 2 and heated to react, it foams to form open cells and is molded.

When the temperature reaches normal temperature, the material becomes a flexible body 3 with high elasticity, so that the molds 1 and 2 can be easily pulled out from the molds 1 and 2 as they are without being disassembled or destroyed.

Further, in the case of a material such as foamed rubber, which completes crosslinking and foaming by heating and loses its plasticity, it can be immediately pulled out without waiting until the molds 1 and 2 reach room temperature.

In either case, it is desirable to make the material as hard as possible within the possible range for ease of handling in subsequent steps.

As described above, even if the material base 3 is highly elastic and the horn is of the sectoral type, multicellular type, or has a complex outwardly convex surface 4, the molds 1 and 2 can be left as they are, and the material There is a great advantage that the base body 3 can be pulled out.

Using the foamed substrate 3 taken out from the molds 1 and 2 as a skeleton, the next step is to cure the foamed urethane using a room-temperature curing agent mixed with a curing resin such as polyester or epoxy in the case of foamed urethane. It is impregnated with 5 to solidify and mold.

In the case of rubber, impregnating it with a thermosetting resin such as melamine or phenol can be inexpensive and shorten the processing steps.

Therefore, in the case of any of the above-mentioned foamed substrates 3, the mold 1,
Immediately after the molding is taken out in step 2, an outer coating is formed all over the outer surface that is in contact with the molds 1 and 2', so the coating is broken in several places to expose the foamed part and then coated. die.

Since it is an open-celled material, impregnation is extremely easy and can be completed in a short period of time.

According to the method of the present invention, metal fittings 6 such as nuts required when using the speaker can be easily inserted by attaching them to the foam base before the impregnation process, and form a male screw 7 such as a connecting part with a driver unit. In this case, by inserting a male screw body 10 made of silicone rubber or Teflon, curing the body, and then removing the male screw body 10, machining of the male screw after impregnation becomes unnecessary, which helps to reduce costs.

In addition, by reducing the degree of impregnation 9 near the opening 8 of the horn and leaving a bubble portion 9, when used as a speaker horn, acoustic loss is maintained and acoustic radiation characteristics deteriorate due to acoustic reflection from the opening 8. can be significantly reduced.

It is also very easy to partially change the state of the horn in this way.

[Brief explanation of drawings]

Figure 1 shows a speaker horn manufactured according to this invention.
FIG. 2 is a cross-sectional view of the mold. 3 is a flexible material base, 5 is a hard material, and 10 is a male screw body.

Claims (1)

[Claims] 1. A foam raw material that reacts and foams at high temperatures, is flexible at room temperature, and forms open cells is reacted and foamed in molds 1 and 2, and then the molds 1 and 2 are decomposed or destroyed. The male threaded body 10 is screwed into the foamed base 3 which is pulled out from the molds 1 and 2 and held therein, and the open cell portions are impregnated with a resin that is curable at room temperature and hardened. A method of manufacturing a speaker horn characterized by removing it.