JPH0214582B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a foamed columnar molded sealing material, which is used as an air sealing material, a water sealing material, etc., and is particularly suitable for use in blower units, cooling units, etc. of automobile air conditioners. The present invention aims to provide a sealing material suitable as a sealing material for a portion connecting heater units.

(Prior Art) Conventionally, a semicircular or semielliptical sealing material itself made of rubber or synthetic resin foam has been known, for example, from Japanese Utility Model Application Publication No. 48-94337, and its manufacturing method is as follows: 1) A method in which unvulcanized rubber sponge raw materials are injected into a mold and then heated and vulcanized.

(2) A method of extruding raw materials through a die.

(3) A method of injecting liquid raw materials such as polyurethane foam into a mold.

(4) A method of compressing and molding a foam sheet using a mold having grooves with an arcuate cross section.

It has been known.

(Problems to be solved by the invention) However, method (1) requires a long thermal formation time;
In addition, when foaming is highly foamed, it changes slightly depending on the degree of vulcanization, making it difficult to obtain a stable product. Method (2) has the drawback that it is difficult to obtain a stable and uniform foam, and in particular, it is difficult to obtain a uniform foam with open cells, making it impossible to obtain a highly foamed product. Since method (3) requires individual molds, large numbers of molds are required for mass production, which is not only expensive but also impossible to produce continuously, resulting in poor workability and inefficiency. be. Moreover, since it is a liquid raw material, it has the disadvantage that pinholes may be generated or the skin may peel off due to small changes in mold temperature. In the method (4), as shown in FIGS. 5a and 5b, when the foam sheet 4 is inserted between the mold 1 in which the arcuate grooves 2 are formed and the flat pedestal 3 and compressed, the upper surface A columnar body 8 having an arcuate portion 5 is obtained. However, an arcuate portion 5 is formed on the upper surface of the foam sheet 4, and the height h of the arcuate portion 5 is directly the height of the product. Therefore, since the length of the arcuate portion 5 of the columnar body 8 is longer than the length of the upper surface 4a of the foam sheet 4, it is pulled from the lower surface 4b of the foam sheet 1.
Therefore, no matter how deep the groove 2 is, the height h of the arcuate portion 5 is limited, resulting in a disadvantage that the height of the product becomes very low.

In addition, since the obtained sealing material is strongly pressed to heighten the arcuate portion 5, it becomes dense, loses flexibility, and becomes hard. If the part to be sealed is a corner, it is difficult to bend, so not only is workability poor, but the seal cannot be used because it cannot adapt to the corner.
Furthermore, in the case of assembled products such as automobiles, the dimensional errors of each product are added together, and the arcuate portion has a low height in areas where the seal gap is large, resulting in many drawbacks such as being unusable.

The purpose of the present invention is to eliminate the drawbacks of conventional methods, especially the drawbacks of the method (4) above, and to easily produce a sealing material with a high arcuate height by using a foam seal and pressing with a mold. The purpose is to provide a method.

The second purpose is that mass production is easy, the height of the arcuate part can be easily adjusted, and products with upper protrusions on the arcuate part or with a skin on the surface can be easily obtained, and flexibility can be improved. It is an object of the present invention to provide a method for manufacturing a sealing material that is easy to hold and install.

(Means for Solving the Problems) As a result of research to achieve the above object, the present invention uses a mold having grooves with an arcuate cross section, and compresses a foam sheet with this mold. As a result, a columnar body is obtained, which alternately includes main body portions having arcuate portions and connecting portions that connect the main body portions. When the center of the main body portion of this columnar body and the connecting portion are cut, a molded sheet material having a height of 1/2 of the length L of the groove bottom can be obtained.

(Function) Therefore, the height of the molded sheet material is the distance between the bottom surface and the tip of the cut main body, so the compression of the foamed sheet by the mold is strong even when obtaining the same arcuate height as before. Since no pressure is required,
Molded sheet materials that maintain flexibility can be easily obtained,
Therefore, the above objective can be achieved.

(Example) In FIGS. 1a and 1b, a mold 1 has a plurality of parallel grooves 2, 2 each having an arcuate cross-section, such as a semicircle or a semiellipse, formed on the lower surface of the mold 1. When the foam sheet 4 is inserted between the mold 1 and the flat base 3 and pressed, the upper surface 4a of the foam sheet 4 is pushed into the grooves 2, 2 of the mold 1, forming an arcuate portion 5. A columnar body 8 is formed which alternately includes main body portions 6 having the arcuate portions 5 and connecting portions 7 that connect the main body portions 6. L is the distance between the openings of groove 2, H
indicates the depth of groove 2.

Next, the center of the main body portion 6 and the center of the connecting portion 7 of the columnar body 8 are cut at a cross section AA and a cross section B-B along the longitudinal direction, respectively. As a result, a molded sealing material 9 having a height equal to 1/2 of the distance L between the openings can be obtained (see FIG. 2). Therefore, by adjusting the positions C and D of the openings, the height of the molded sealing material 9 can be adjusted, and a high-height molded sealing material 9 can be easily obtained. Further, as a result of cutting the connecting portion 7 in this manner, the projection 10 remains along the longitudinal direction at the upper end of the arc-shaped portion 5 of the molded sealing material 9.
0 comes into close contact with one of the parts to be sealed when used as a sealing material, further enhancing the sealing effect.

In FIGS. 3a and 3b, another embodiment of the invention is shown, in which the molds 1, 1 form a pair, both molds 1,
Grooves 2, 2 similar to those in the above-mentioned embodiment are formed on the lower and upper surfaces of the molds 1, facing each other, and when a foam sheet 4 is sandwiched between the molds 1 and 1 and pressed simultaneously, arc-shaped parts 5, 5 is formed into an oval main body portion 6
A columnar body 8 is formed. Then, when this is cut along the cross section A-A and the cross section B-B in the same manner as in the above embodiment, a molded sealing material 9 having a protrusion 10 at the top of the arcuate portion 5 is obtained as shown in FIG. . In this method as well, the height of the arcuate portion is not obtained by pushing it into the groove of the mold as in the conventional method, but is obtained by cutting it, so the pressing force can be small. Therefore, since the molded sealing material 9 is not compressed to a large extent, it maintains its flexibility and has excellent workability.

The foam sheet used in the present invention includes:
Foamed materials such as rubber and synthetic resin, such as natural rubber,
Those made of synthetic rubber, olefin polymers such as polyethylene, polypropylene and propylene, vinyl polymers such as vinyl chloride, and polyurethane can be used. When trying to obtain a water-stopping sealant, it is preferable to use hydrophobic raw materials.
In the case of thermoplastic resin, the molding method involves heating a foamed sheet, cooling a mold, and pressing. In the case of thermosetting resin, the mold is heated and pressed.

When polyurethane is used as a raw material, it is preferable to use polybutadiene polyurethane or dimer acid polyurethane using a hydrophobic raw material as the polyurethane raw material. In order to further increase the hydrophobicity, it is possible to add oil, petroleum resin, polybutene, etc. mainly composed of hydrocarbons, which reduce the hydrophobicity. In the case of polyurethane using a general-purpose ether or ester, it is preferable to add the above-mentioned substance imparting hydrophobicity.

The foam may be an open cell or a closed cell. In the case of closed cell foam, it is necessary to press it with a considerable amount of pressure, so a large amount of pressure is required to insert the sealing material between the sealing members when installing it. On the other hand, in the case of open-cell foam, when installing the seal material, only a small amount of pressure is required to avoid scratching between the seal members, and especially when the strength of the member to be sealed is low, there is a smooth surface between the bolts that tighten the seal material. This is preferable in that it can be inserted into.

Further, if a foam sheet having a skin on the surface is used, a sealing material with a skin on the surface can be easily obtained. In addition to the above, this sealing material with skin has
The skin may be formed by molding during manufacture, by pasting a film, or by melting the surface with heat or the like. Further, an adhesive tape 11 such as double-sided tape may be attached to the bottom of the obtained sealing material, as shown in FIGS. 2 and 4.

(Effects of the Invention) As described above, according to the present invention, a foam sheet is pressed by a mold in which at least two grooves having an arcuate cross section are formed in parallel, and a main body portion having an arcuate portion and a A columnar body is formed which alternately includes connecting portions connecting the main body portions, and the center of the main body portion and the connecting portion of this columnar body are cut along the longitudinal direction to form a molded sealing material. Therefore, it is easy to obtain semicircular, elliptical, etc. arcuate parts with a high height, and the height can be easily adjusted, so that they can be used in locations where the seal gap changes greatly. In addition, since the obtained sealing material is not highly compressed and is flexible, it can be easily installed between sealing members, and is well suited to corner portions, and at the same time, the burden on the operator is small, and the workability is extremely high. Furthermore, since a product having a protrusion at the top of the arcuate portion is obtained, the sealing performance can be improved not only by the arcuate portion but also by the protrusion.

[Brief explanation of drawings]

FIGS. 1a and 1b show an embodiment of the present invention;
Figure a is a perspective view showing the state before pressing the foam seal, Figure 1 b is a perspective view of the formed columnar body, and Figure 2 is a perspective view showing the molded seal material molded by the same manufacturing method. 3a and 3b show other embodiments of the present invention, FIG. 3a is a perspective view showing the state before pressing the foam seal, and FIG. 3b is a perspective view of the formed columnar body. FIG. 4 is a perspective view showing a molded sealing material molded by the same manufacturing method as above, FIGS. 5a and 5b show a conventional example, and FIG. FIG. 1b is a perspective view of the formed columnar body. 1... Molding mold, 2... Groove, 4... Foaming sheet,
5... Arc-shaped part, 6... Main body part, 7... Connecting part, 8
... Column, 9... Molded sealing material.

Claims (1)

[Claims] 1. A foam sheet is pressed by a mold in which at least two grooves having an arcuate cross section are formed in parallel to form a main body portion having an arc-shaped portion and a connecting portion connecting the main body portions. 1. A method for producing a foamed columnar molded sealing material, which comprises forming alternating columnar bodies, and cutting the center and connecting portions of the main bodies of the columnar bodies along the longitudinal direction. 2. The method for manufacturing a foamed columnar molded sealing material according to claim 1, wherein the molds form a pair and arcuate portions are formed on both sides of the main body of the columnar body.