JPS61140674A - Manufacturing of formed foam sealing rod - Google Patents

Abstract

PURPOSE:To easily form foam sealing rods by pressing a foam sheet by a forming die having a plurality of grooves of arcuate section arranged in parallel and cutting the joints between the rods of the foam sheet. CONSTITUTION:A forming die 1 has on the lower surface thereof a plurality of semicircular grooves 2 of arcuate section arranged in parallel. A foam sheet 4 is inserted and pressed between the forming die 1 and a plane base table 3 to form arcuate members 5 on the upper surface 4a of the foam sheet 4. There are left between adjacent body members 6 of the arcuate members 5 joints 7, which are cut longitudinally to obtain formed sealing rods 9.

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 used in the pro-a unit, cooling unit, etc. of an automobile air conditioner. 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 was disclosed in, for example, Japanese Utility Model Application Publication No. 48-943.
It is known from Publication No. 37, and its manufacturing methods include: (1) A method in which a rubber sponge raw material before vulcanization is injected into a mold, and then heat is applied to vulcanize it.

(2) A method of extruding raw materials from 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) has the drawback that the heat forming time is long, and when the foaming is high, the degree of vulcanization changes slightly, making it impossible to obtain a stable product. The 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. (3)
Since the method requires individual molds, a large number of molds are required for mass production, which is not only expensive, but also impossible to produce continuously, resulting in poor workability and inefficiency. 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. 5(a) and 5(b), a foamed sheet 4 is placed in a mold having arcuate grooves 2 formed therein.
When it is inserted between the base 3 and the flat pedestal 3 and compressed, a columnar body 8 having an arcuate portion 5 on the upper surface is obtained. However, the arcuate portion 5 is formed on the upper surface of the foam sheet 4, and the height h of the arcuate portion 5 is
is the same as 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, and therefore, no matter how deep the groove 2 is , arcuate portion 5
The height h of the product was limited, and the height of the product was very low.

Further, since the obtained sealing material is strongly pressed to make the arcuate portion 5 high, it becomes dense, loses flexibility, and becomes hard. If the part to be sealed is a corner, it is difficult to bend, which not only results in poor workability, but also makes it impossible to use the seal as it cannot be adapted to the part of 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 the area 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 the conventional method, and in particular to
) eliminates the disadvantages of the method and uses foam seals,
An object of the present invention is to provide a method for easily manufacturing a sealing material having a high arcuate portion by pressing with a mold.

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 inventor 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 of the groove bottom can be obtained.

(Function) Therefore, since the distance between the bottom surface and the tip of the cut main body is the height of the molded sheet material, compression of the foamed sheet with a mold requires strong pressure even when obtaining the same arcuate height as before. Since this is not necessary, a molded sheet material that maintains flexibility can be easily obtained, and therefore the above object can be achieved.

(Example) In Fig. 1 (al, (bl), the bent mold 1 has a groove 2°2 having an arcuate cross section such as a semicircular or semielliptical shape on the lower surface of the mold 1.
are formed in parallel. 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. Main body portion 6 having this arcuate portion 5
A columnar body 8 is formed which alternately includes 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 part 6 and one end of the connecting part 7 of the columnar body 8 are cut along 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 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 can be easily obtained.

Furthermore, 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 arcuate portion 5 of the molded sealing material 9, and when used as a sealing material, the projection 10 remains. It comes into close contact with one of the parts to be sealed, further enhancing the sealing effect.

In FIGS. 3(al and bl), another embodiment of the invention is shown, in which the mold 1.1 is arranged in pairs, and the lower and upper surfaces of the remolding mold 1.1 are respectively similar to the previous embodiment. Grooves 2, 2 are formed facing each other, and a foam sheet 4 is formed between the molds 1.1.
When both are sandwiched and pressed at the same time, a columnar body 8 having an elliptical main body part 6 with upper and lower arcuate parts 5, 5 formed therein 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, the molded sealing material 9 is thick (it is not compression molded, so it maintains flexibility) and has excellent workability.

The foamed sheets used in the present invention include foamed materials such as rubber and synthetic resins, such as those made of natural rubber, synthetic rubber, olefin polymers such as polyethylene, polypropylene, and propylene, vinyl polymers such as vinyl chloride, and polyurethane. can get. 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, the skin-attached sealing material may be formed at the time of manufacture, or a skin may be formed by pasting a film or melting the surface by 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 connection parts connecting the main body parts, and the center of the main body part and the connection part 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, the obtained sealing material is not highly compressed and is flexible, so it is easy to attach between sealing members, and it is well suited to a part of a corner, 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 the drawing]

FIGS. 1(a) and 1(b) show an embodiment of the present invention, FIG. 1'+8) is a perspective view showing the state before pressing the foam seal, and FIG. FIG. 2 is a perspective view showing a molded sealing material molded by the same manufacturing method as above, and FIG. Figure (al) is a perspective view showing the state before pressing the foam seal, Figure 3 (b) is a perspective view of the formed columnar body, and Figure 4 is the molded seal material molded by the same manufacturing method. FIG. 5(a) is a perspective view showing the
), (b) shows a conventional example, FIG. 5 (al) is a perspective view showing the state before pressing the foam seal, and FIG. ...Mold, 2...Groove, 4...Foam sheet, 5
...Arc-shaped part, 6...Main body part, 7...Connection part, 8.
... Column, 9... Molded sealing material. Figure 3 (a) $581 (a) Figure 311 (b) Figure 5 (b) Procedural amendment (October 17, 1985 l.Indication of incident 1981 Patent Application No. 259267 Case Relationship with Representative Mochizuki of Patent Applicant Figure 3 (b) 7. Contents of amendment (1) The term ``one end'' on page 6, line 9 of the specification is amended to read ``center''. 3 Correct @(b) as shown in the attached sheet.

Claims (1)

[Claims] 1. A foamed 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 arcuate portion and a connecting portion connecting the main body portions. 1. A method for manufacturing a foamed columnar molded sealing material, which comprises forming a columnar body having alternating bases, and cutting the center and connecting portions of the main body of the columnar body 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.