JP6541125B2 - Method of manufacturing rubber heater - Google Patents

Description

  The present invention relates to a rubber heater which is a flexible planar heating element and a method of manufacturing the same.

  A rubber heater in which an electric resistance type heater is covered with a heat resistant rubber such as silicon rubber or fluorine rubber has a characteristic that it can be brought into close contact flexibly along the surface shape of an object to be heated. reference).

JP-A-9-63755 Utility model registration No. 3133051

  However, in the conventional rubber heater described above, even if it is attempted to closely contact a curved surface having a small radius of curvature, it is difficult to heat uniformly since a gap is easily formed due to wrinkles.

  The present invention has been made in view of the above-mentioned conventional circumstances, and it is an object of the present invention to provide a rubber heater which can be in close contact without gaps and uniformly heated according to the shape of an object to be heated. I assume.

  The rubber heater according to the present invention is a rubber heater for heating an object to be heated, which has a shape matched to the surface shape of the object to be heated, and is provided with an electric resistance heater which can be bent inside It is characterized by

  In the rubber heater of the present invention, since it has a shape matched to the surface shape of the object to be heated, it can be brought into close contact with the object to be heated without a gap, and wrinkles will not occur. Then, the object to be heated can be uniformly heated by energizing the electric resistance type heater in the close contact state.

  The electrical resistance heater is not particularly limited as long as the rubber heater can exhibit flexibility. As such an electrical resistance type heater, a heater using an electrical resistor such as a metal such as nichrome or carbon as a heating element can be used. The shape of the heater may be linear or planar. Moreover, as a raw material of a rubber, silicone rubber, fluorine rubber, etc. can be used, for example. In order to enhance mechanical strength, it is also preferable to reinforce the rubber with heat resistant fibers. The heat-resistant fiber is not particularly limited, and for example, glass fiber can be used.

The rubber heater of the present invention can be manufactured as follows.
That is, the method of manufacturing a rubber heater according to the present invention is
A method of manufacturing a rubber heater for heating an object to be heated, comprising:
A first step of preparing a first mold having the same surface shape as the object to be heated;
Covering the surface of the first mold with a rubber before curing;
A third step of preparing a second mold that conforms to the surface shape of the rubber before curing;
After covering the surface of the second mold with a rubber before curing, a fourth step of arranging an electric resistance heater on the surface of the rubber before curing;
A fifth step of covering the electric resistance type heater with rubber before curing and heating it to form a rubber layer with a heater;
A sixth step of peeling the heater-attached rubber layer from the second molding die;
A seventh step of covering the uncured rubber covered with the heater-provided rubber layer on the surface of the first molding die and curing the uncured rubber to obtain a rubber heater and the rubber heater from the first molding die An eighth step of peeling;
And the like.

  Here, the rubber before curing is not particularly limited as long as it is cured by heat and / or aging. For example, a rubber plate material before curing, a liquid rubber before curing, a gel-like rubber before curing, and the like can be mentioned. Further, as the rubber before curing, those of a room temperature curing type and a heat curing type can be used. Furthermore, as a raw material of rubber, in addition to silicon rubber, fluorine rubber can also be used.

In the method of manufacturing a rubber heater according to the present invention,
It is preferable to provide a jig for arranging the electric resistance heater in the second molding die. If this is done, it becomes easier to dispose the electrical resistance type heater. As a jig in this case, for example, a plurality of guide pins provided upright in the second molding die may be used as a jig, and an electric resistance heater may be wound around it.

Example 1
The rubber heater of Example 1 is used for repairing a radome. A radome is a shell shaped cover that covers the tip of an aircraft, and a radar device is installed inside. For this reason, the radome is made of glass fiber reinforced epoxy so that radio waves can be transmitted. If pebbles or birds hit the radome and the surface is scratched, it needs to be repaired. As a method of repair, after polishing the scratched part, it is covered with a glass fiber reinforced epoxy before curing and heated from the surface for curing. The rubber heater of Example 1 is used for heating at this time.

  As shown in FIG. 1, the rubber heater 1 of Example 1 is made of silicone rubber and has a shape matched to the surface shape of the radome 100 (upper left in FIG. 1). Is made possible (Figure 1, right). As shown in FIG. 2, the rubber heater 1 is joined so that the inner rubber layer 1a and the rubber layer 1b with a heater in which the nichrome wire 2 is spirally wound at equal intervals overlap each other. Both ends of the nichrome wire 2 are connected to the wire 3.

<Method of manufacturing rubber heater>
The rubber heater 1 is manufactured as follows.
(Step 1)
As a first step, as shown in FIG. 3A, a hat-shaped first mold 4 having the same surface shape as the surface of the radome 100 is prepared.
(Step 2)
Next, as a second step, as shown in FIG. 3B, a plurality of fan-shaped unvulcanized rubber plates 5 are prepared on the surface of the first molding die 4 and laid so as to have no gap. Here, the rubber plate 5 before vulcanization is the rubber before curing. A liquid or gel silicone rubber before curing may be used instead of the rubber plate before vulcanization.
(Third step)
On the other hand, separately from the first molding die 4, a second molding die 6 is prepared which matches the surface shape of the unvulcanized rubber plate 5 laid after the second step (see FIG. 4 (c)).
(Step 4)
A plurality of recesses 7 are provided on the surface of the second mold 6 (see FIG. 4D), one end of the guide pin 8 is fitted in the recess 7 and the other end is protruded. A plurality of pre-vulcanized rubber plates 9 are prepared and laid (see FIG. 4 (e)). Here, the rubber plate 9 before vulcanization is the rubber before curing. A liquid or gel silicone rubber before curing may be used instead of the rubber plate before vulcanization.
Then, the nichrome wire 10 is wound along the guide pin 8, and the electric wire 3 is connected to the end of the nichrome wire 10 (see FIG. 4 (f)).
(Step 5)
Further, a plurality of fan-shaped unvulcanized rubber plates 11 are prepared from above the nichrome wire 10, and laid (see FIG. 4 (g)). Then, the pre-vulcanization rubber plate 11 is vulcanized by heating in a vacuum heating furnace to form a heater-provided rubber layer 12. Here, the rubber plate 11 before vulcanization is the rubber before curing. A liquid or gel silicone rubber before curing may be used instead of the rubber plate before vulcanization.
(Step 6)
And the rubber layer 12 with a heater (FIG. 5 upper side) is peeled from a 2nd shaping | molding die.
(Step 7)
Further, as shown in FIG. 5, the heater-provided rubber layer is placed on the pre-vulcanization rubber plate 5 after the completion of the second step. Then, the heater-equipped rubber layer 12 is adhered to the rubber plate 5 before vulcanization by heating in a vacuum heating furnace. In addition, if liquid or gelled room temperature curing silicone is used instead of the rubber plate 5 before vulcanization, it becomes possible to bond without using a vacuum heating furnace.
(Step 8)
Finally, the rubber heater 1 is peeled off from the first mold 4 to obtain the rubber heater 1 of Example 1 shown in the upper left of FIG.

<How to use rubber heater>
The usage method of the rubber heater 1 of Example 1 comprised as mentioned above is demonstrated.
After grinding the damaged portion 100a (see FIG. 6a) of the radome 100 with a grinder, it is polished using a file to form a polished portion 100b (FIG. 6b). Then, the uncured glass fiber reinforced epoxy member 20 for repair is cut out slightly larger than the shape of the polishing portion 100b, and placed on the polishing portion 100b (FIG. 6c). Then, after covering the entire radome 100 with a fluorine resin film for release not shown, the rubber heater 1 of Example 11 is placed on the radome 100 (FIG. 6 d). Then, the pressure is reduced by a vacuum bag not shown. Thereby, the inside of the rubber heater 1 is depressurized, and the atmospheric pressure causes the rubber heater 1 to compress the glass fiber reinforced epoxy member 20 before curing (FIG. 6 e).

Then, the nichrome wire 10 is energized and heated. Thus, by heating while pressing the uncured glass fiber reinforced epoxy member 20 by the rubber heater 1, the uncured glass fiber reinforced epoxy member 20 is polymerized and is surely bonded to the abrasive portion 100 b. After adhesion is performed in this manner, the evacuation by the vacuum pump and the energization to the rubber heater 1 are stopped, the rubber heater 1 is removed, and the surface is polished with a grinder or a sandpaper to complete the repair.
Since this rubber heater 1 is shaped to conform to the surface shape of the radome 100, it can be in close contact with the entire surface of the radome 100 and can be uniformly heated. The polymerization reaction of can also be carried out uniformly. Therefore, the reliability of the repair is also high. Further, the nichrome wire 10 has a shape in which it is sandwiched by silicon rubber from both sides and has a uniform thickness, so there is no easily bendable portion and the nichrome wire 10 is hard to break.

Comparative Example 1
The rubber heater of Comparative Example 1 is a rubber layer with a heater (upper side in FIG. 5) obtained by performing the third to sixth steps in Example 1, and the seventh step in Example 1 is not performed. Therefore, the rubber is thin at the portion where the guide pin 8 is fitted, and it is easy to be bent at that portion, and the nichrome wire is easily broken. Moreover, when heating using this rubber heater, heating tends to be uneven.

  The present invention is not limited to the description of the embodiments and examples of the above-mentioned invention. Various modifications are also included in the present invention as long as those skilled in the art can easily conceive without departing from the scope of the claims.

  The rubber heater according to the present invention can be in close contact without gaps and uniformly heated according to the shape of the object to be heated. For this reason, it can be suitably used for repair using a glass fiber reinforced epoxy before curing of a broken part of FRP, for production of an FRP molded product, and the like.

1 ... rubber heater 100 ... radome (heated object)
DESCRIPTION OF SYMBOLS 1a ... Inner rubber layer 1b ... Rubber layer with a heater 4 ... 1st shaping | molding type | mold 6 ... 2nd shaping | molding type | mold 5, 9 ... Rubber plate before vulcanization (rubber before hardening)
8: Guide pin (jig)
10 ... Nichrome wire (electrical resistance heater)

FIG. 2 is a perspective view showing a usage state of the rubber heater 1 of Example 1; FIG. 2 is a partial cross-sectional view of the rubber heater 1 of Example 1; FIG. 7 is a perspective view showing a first step and a second step when manufacturing the rubber heater 1 of Example 1; FIG. 7 is a view showing third to sixth steps when manufacturing the rubber heater 1 of the first embodiment. It is a perspective view which shows the 7th process and the 8th process when manufacturing the rubber heater 1 of Example 1. FIG. FIG. 6 is a perspective view showing a method of repairing the radome 100 by the rubber heater 1 of the first embodiment.

Claims (3)

A method of manufacturing a rubber heater for heating an object to be heated, comprising:
A first step of preparing a first mold having the same surface shape as the object to be heated;
Covering the surface of the first mold with a rubber before curing;
A third step of preparing a second mold that conforms to the surface shape of the rubber before curing;
After covering the surface of the second mold with a rubber before curing, a fourth step of arranging an electric resistance heater on the surface of the rubber before curing;
A fifth step of covering the electric resistance type heater with rubber before curing and heating it to form a rubber layer with a heater;
A sixth step of peeling the heater-attached rubber layer from the second molding die;
A seventh step of covering the uncured rubber covered with the heater-provided rubber layer on the surface of the first molding die and curing the uncured rubber to obtain a rubber heater and the rubber heater from the first molding die An eighth step of peeling;
Method of manufacturing a rubber heater comprising: Method for producing a rubber heater according to claim 1, wherein the jig for arranging the electric resistance heater in the second mold is provided. The method for manufacturing a rubber heater according to claim 2 , wherein the jig comprises a plurality of guide pins provided upright on the second molding die.

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