JPH0688285B2 - Method for manufacturing heat insulating member made of synthetic resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a heat-generating member formed in a thin layer, which is molded in a layered manner in a member, for example, an electric insulation type toilet seat, a baby bathtub, etc. The present invention relates to a method for manufacturing a synthetic resin heat insulating member that constitutes a main part.

<Prior Art> A typical method for manufacturing a conventional synthetic resin heat insulating member in the above industrial application field is to first form a first layer constituting the heat insulating member main body, which is made of stainless steel or the like. The foil-shaped heating element is placed, and the plastic synthetic resin forming the second layer is directly injected to the upper side of the foil-shaped heating element from the female injection hole arranged on the other side of the heating element.

As a similar technique, as disclosed in Japanese Utility Model Publication No. 62-39595, there is a technique relating to a heat-retaining toilet seat by so-called sandwich injection molding.

Further, in the prior art which can be referred to as a method for producing a molded product having a multi-layered structure, Japanese Patent Laid-Open No. 62-275727 relating to electromagnetic wave shield molded products and Japanese Patent Laid-Open No. 62-27 related to molding of key tops
No. 9911 and Japanese Patent Laid-Open No. 63-69612 regarding molding of window weather strips for automobiles.

<Problems to be solved> In the conventional method for manufacturing a heat insulating member made of a synthetic resin centering on a heat-retaining type toilet seat, the thickness of the thin layer heating element is usually formed to about 5 μm, and the synthetic resin is placed in the cavity. In the case of directly injecting, the injection amount is large and the injection pressure is considerably high if the injection is performed directly toward the heating element, so that the thin layered heating element often breaks.

To such a problem, the sandwich injection molding method, which is a similar technology to the above, cannot be an effective solution, and the technology related to the electromagnetic wave shield molded product, the technology related to the molding of the key top, the automobile related to the above, which is a reference technology, Although the technology related to the molding of window weather strips for automobiles is a method of manufacturing a molded product that is formed by sandwiching layered materials or sandwiching them in multiple layers, it is far from a means for solving the breakage during molding of thin layered materials. Is.

In view of the above problems, the present invention provides a synthetic resin heat insulating member that is less likely to be broken during molding of the synthetic resin heat insulating member that sandwiches the thin-layered heat generating element inside in a layered manner. It is intended to provide a manufacturing method.

<Means for Solving the Problem> In the present invention, the first cavity space 2 is filled with a plastic flow synthetic resin, and the first constituent layer 1 molded by this step is unmounted from the first cavity 2 to make it The heating element 6 formed in a thin layer is placed on the female die 9, and the heating element 6 formed in a thin layer is placed on the upper surface of the first constituent layer 1 placed on the first female die 9. After the second female mold 10 that faces the female mold 9 and composes the second cavity space 8 is fitted together, an injection projecting in the vicinity of the heating element mounting surface in the second cavity space 8 is performed. The means for solving the above-mentioned problem is to inject the plastic flow synthetic resin from the holes 11 and 12 toward the bottom of the second female engraving surface to form the second constituent layer 7 by double-adhesion molding.

<Operation> In the means for solving the above problems, the first constituent layer is first molded in the first cavity. When the plastic flow synthetic resin is injected toward the second female engraved bottom face from the injection hole protruding in the vicinity of the placement surface of the heating element placed on the upper surface of the first constituent layer, the flow synthetic resin is The two female type engraved bottoms are filled with the second cavity while being entangled with the engraved bottoms, or reflected and dropped from the engraved bottoms.

In this molding process, the fluid synthetic resin injected at high pressure
Since it passes through the bottom of the second female engraving, the injection pressure drops significantly, and the flowing synthetic resin that reflects and drops from the bottom of the engraved surface toward the heating element already breaks the thin layer heating element. It doesn't have the momentum to make it happen. Therefore, the possibility of breakage of the heating element during the process of filling the second cavity with the synthetic resin is significantly reduced.

<Example> An example of a method for producing a heat insulating member made of a synthetic resin of the present invention will be described below.
It will be described in detail with reference to the drawings.

The heat insulating member made of a synthetic resin referred to in the present invention is typically a heat insulating type toilet seat. Therefore, when a sectional view is referred to below, it shows a portion formed into a horseshoe shape, or a longitudinal section of a horseshoe-shaped cavity.

FIG. 1 is used in an embodiment (hereinafter, abbreviated as this embodiment) of the method for manufacturing a synthetic resin heat insulating member according to the present invention, and is used to mold a first constituent layer 1 which is a constituent member of the synthetic resin heat insulating member. It is sectional drawing of the cavity 2.

As shown in FIG. 1, the first cavity 2
Is a space surrounded by the first cavity female die 3 and the female die cover plate 4. The first cavity injection hole 5 for injecting the flow synthetic resin into the first cavity 2 is formed at an appropriate position on the bottom of the engraving surface of the first cavity female die 3.

A convex portion 3a for forming the fitting hole 1a in the first component layer 1 is formed in the central portion of the first cavity female mold 3.

FIG. 2 shows the synthetic resin heat insulating member in this embodiment, which is a heat insulating type toilet seat as a specific example. The second constituent layer 7 sandwiches the heating element 6 which is a constituent member of the heat insulating type toilet seat. It is a sectional view of the second cavity 8 used for heavy-duty molding.

As shown in FIG. 2, the second cavity 8
Is a space surrounded by the first female mold 9 in the lower half of the second cavity and the second female mold 10 in the upper half of the second cavity. The first female die 9 and the second female die 10 are opposed to each other, and the second female die 10
The engraved surface of is homogeneous and smooth.

Since the above-mentioned synthetic resin heat insulating member product is a heat-retaining type toilet seat, it is desirable that a toilet bowl edge fitting groove is formed on the lower back surface of the product. Therefore, the first female die 9 has a peripheral portion of its engraved surface. Is carved deeper than other parts like 9a.

At the center of the engraving surface of the first female die 9, an injection table 11 for injecting a fluid synthetic resin is provided so as to project from the engraving surface toward the second female die 10, and at the center of the injection table 11 is a second cavity. An injection hole 12 is provided. This injection table 11 and the second cavity injection hole
As shown in FIG. 3 which is a schematic plan view of the second cavity, the 12 are arranged in a line along the center line of the horseshoe shape.

In the first female die 9, the peripheral portion 9a, the injection table 11, and the portion other than the second cavity injection hole 12 are engraved in a flat shape, and the flat engraved surface 9b is formed by the first cavity 2 One constituent layer 1 is placed. The flat engraving surface 9b is slightly smaller than the first constituent layer 1, and therefore the peripheral edge portion 1b of the placed first constituent layer 1 projects into the second cavity space.

When the first constituent layer 1 is placed on the flat engraved surface 9b, the fitting hole 1a formed in the first constituent layer 1 fits into the injection table 11 and a gap is formed on the contact surface. Therefore, the first component layer 1 is closely fitted to the first female die 9 and is thus fitted. Also at this time the injection table
The top of 11 slightly protrudes from the upper surface of the fitted first component layer 1.

FIG. 4 is a schematic plan view of the heating element 6. As shown in FIG. 4, the heating element 6 placed on the first component layer 1 is a foil-shaped heating element main body 6a on which electric wiring is laid and covered with an extremely thin vinyl chloride sheet 6b. , The thickness is within 5 microns and outside. Further, although the plane shape of the heating element 6 is not shown,
It is substantially similar to the planar shape of a heat insulating member product made of synthetic resin such as a heat insulating type toilet seat.

Under the above-mentioned structure, first, the first cavity 2 is injected with the fluid synthetic resin through the first cavity injection hole 5 to fill the first cavity 2, and the first component layer 1 is molded.

As shown in FIG. 5, which is a schematic plan view of the first constituent layer 1, the molded first constituent layer 1 has a horseshoe-shaped planar shape, and the fitting holes 1a are arranged along the center line thereof. To be done. The first constituent layer 1 is fitted on the first female die 9 of the second cavity 8. At this time, the fitting hole 1a is fitted into the injection table 11 arranged along the center line of the first female mold 9 along the center line.

Next, the heating element 6 is placed on the upper surface of the first component layer 1 fitted in the first female die 9 in this manner, and the second female die is placed thereon.
10 is faced to each other and a second cavity space is formed.

In the second cavity space formed by the above process, the second cavity injection hole 12 formed in the center of the injection table 11 this time.
Then, the fluid synthetic resin is injected at a high pressure toward the bottom surface of the second female mold 10 to form the second component layer 7 by superposition.

The fluid synthetic resin injected at a high pressure from the second cavity injection hole 12 either radiates to the engraved bottom surface of the second female mold 10 or is reflected or dropped from the engraved bottom surface, in the direction of the arrow shown in FIG. The second cavity space is filled while flowing.

In this way, the fluid synthetic resin that is entangled with the engraved bottom surface of the second female mold 10 or that is reflected and dropped from the engraved bottom surface is the second female mold.
Since it passes through the engraved bottom surface of 10, the injection pressure is significantly reduced, and it does not have enough momentum to cause the heating element 6 to break.

Further, since the top of the injection table 11 slightly projects from the upper surface of the fitted first component layer 1, the injection flow synthetic resin does not directly hit the heating element 6 from the injection hole and cause breakage. , And on the lower surface of the second constituent layer 7 when the molding is completed,
There is no formation of inconvenient protrusions during product installation.

On the other hand, the peripheral edge of the first female engraving surface is 9a
As shown in Fig. 6 which is a cross-sectional view of the molded product, the toilet edge fitting groove 13 is formed in the lower part so that it has a shape suitable for installation and use of the product. Molded.

Through the steps described above, the heating element 6 is sandwiched between the first constituent layer 1 and the second constituent layer 7 while maintaining the initial state without being broken by the high-pressure injection of the fluid synthetic resin, and Since the engraved surface of the two-female mold 10 is uniform and smooth, no unevenness that would be inconvenient during use is formed on the use surface of the molded product.

Note that the embodiment of the present invention is not limited to the above-mentioned heat-retaining type toilet seat, and is a heat-insulating member made of a synthetic resin that intercalates a heating element that easily breaks during molding, such as a warm carpet insole of a floor heating device. It can also be applied to molding baby bathtubs, etc.

<Effects of the Invention> As described in detail above, according to the method for manufacturing a synthetic resin heat insulating member of the present invention, a synthetic resin that sandwiches a thin layered heating element formed in a thin layer that easily breaks inside in a layered manner. Made heat insulating material,
For example, there is provided a method for manufacturing a heat insulating member made of synthetic resin, which is less likely to cause breakage of a heating element during molding of a heat-retaining toilet seat of a Western-style toilet, a hotbed of a floor heating device, a baby bathtub, and the like.

[Brief description of drawings]

FIG. 1 is a sectional view of a first cavity used in an embodiment of the method for manufacturing a heat insulating member made of synthetic resin of the present invention, and FIG. 2 is a sectional view of a second cavity used in the embodiment,
3 is a schematic plan view of the same second cavity, FIG. 4 is an enlarged schematic plan view of a heating element, FIG. 5 is a schematic plan view of a first component layer, and FIG.
The figure is a cross-sectional view of a molded product. DESCRIPTION OF SYMBOLS 1 ... 1st component layer, 1a ... Fitting hole, 2 ... 1st cavity, 3 ... 1st cavity female type, 3a ... 1st cavity female type convex part, 4 ... Female type cover plate 5 ... First cavity injection hole, 6 ... Heating element, 6a ... Heating element main body, 6b ... Vinyl chloride sheet, 7 ... Second constituent layer, 8 ... Second cavity, 9 ... 1-female type, 9a ... first female-type peripheral portion, 9b ... first female-type plane engraving surface, 10 ... second female-type, 11 ... injection table,
12 …… Second cavity injection hole, 13 …… Toilet edge fitting groove.

Claims (1)

[Claims] 1. A first cavity space is filled with a plastic flow synthetic resin, and the first constituent layer molded by this step is dismounted from the first cavity and mounted in a first female mold. A heating element formed in a thin layer is placed on the upper surface of the first component layer fitted in the mold, and then a second cavity is formed on the upper part of the heating element so as to face the first female mold. After the two female molds are fitted together, in the second cavity space, the plastic flow synthetic resin is injected from the injection hole protruding near the heating element mounting surface toward the bottom of the second female mold engraving surface. A method of manufacturing a heat insulating member made of synthetic resin, characterized in that the second constituent layer is subjected to heavy-duty molding.