JPS63209814A - Manufacture of packing for sealing - Google Patents

Abstract

PURPOSE:To obtain a packing for sealing having excellent airtightness and water resistance and difficult to be peeled off in handling work while forming a skin layer onto the surface by foaming a stock solution injected into an annular cavity shaped to one of molds in the mold. CONSTITUTION:A predetermined cavity 12 is formed in either one of a pair of upper and lower molds 10, 11, and a nozzle 14 for injecting a foaming stock solution 13 is shaped on the side oppositely faced to the cavity 12. The foaming stock solution 13 is charged previously into the cavity 12 by the nozzle 14, the stock solution is foamed through heating, a chemical reaction, etc., and a packing P for sealing having a prescribed shape matching with a specified unit is monolithically molded. When the stock solution is foamed in the cavity 12, bubbles in sections which are brought into contact with the molds 10, 11 are fined and thickened. thus a packing P for sealing covered with a smooth skin layer is formed to which holes, etc., are hardly bored.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method of manufacturing a sealing gasket used at a joint between units in an automotive air conditioner.

(Prior Art) In general, an air conditioner for an automobile has the following features as shown in FIG.
An intake unit 1 that takes in air from outside and outside the vehicle interior and blows it; a cooler unit 2 that has a built-in evaporator that cools the passing air; It has a heater unit 3 for distributing air to.

Each of these units 1, 2.3 is molded separately and is connected at the bottom of the instrument panel 4, but at the time of this connection, a flange f is formed at the joint end of each unit 1, 2.3, A sealing gasket P for preventing air leakage is interposed between each of the flange portions f.

This sealing gasket P is affixed to one of the flange parts f (on the cooler unit 2 side in Fig. 5) that are butted against each other, and is deformed under pressure by each flange part f, and is formed inside. Maintains air-tightness of air passages.

This sealing gasket P is generally formed into an annular shape so as to form an air passage inside, but conventionally, in order to manufacture this sealing gasket P, as shown in FIGS. 6 and 7, Let's do it.

The sealing gasket PI shown in FIG. 6(a) is made by cutting a straight long cord-like member made of foamed urethane material or the like and having a rectangular or almost circular cross section to a predetermined length. It is formed into an annular shape along the flange part f, and the joints 5 at both ends thereof are made to match so that no gaps are formed.

Then, attach this sealing gasket P+ to both flanges f, f.
The double-sided tape 6 is attached to either one of the two flanges f and r, and the two flanges f and r are used to clamp the tape between the two flanges f and r.

The sealing gasket P2 shown in FIG. 7(a) is made of a long and thin rectangular elastic member such as foamed urethane material, and a notch 7 is made in the center of this elastic member leaving both ends, and is divided by the notch 7. Both pieces 8a and 8b are opened in opposite directions and formed into a rectangular ring shape.
As shown in Figure (b), the ends of both units 1 and 2
a, 2a are partially protruded, one piece 8a of this packing P2 is attached to the outer periphery of the unit, and the other piece 8b is attached to the inner periphery, and this is pressurized by the end of the other unit. It is something.

(For example, see Utility Model Publication No. 55-34,090).

(Problems to be Solved by the Invention) However, when forming a straight piece into an annular shape like the sealing packing P1 shown in FIG. 6, the joint 5 at the end not only causes wind leakage but also , wrinkles 9 are formed at the corners, which may cause sealing failure.

Further, as shown in FIG. 7(a), there is also a sealing gasket P2 in which both pieces 3a and 8b separated by the notch 7 are opened in opposite directions and formed into a rectangular ring shape, as shown in FIG. 7(a). Similar to the above, there are wrinkles 9 at the corners, which may cause a seal failure, and since both pieces are opened in opposite directions around the notch, each piece is separated as shown in Figure 8. Due to the characteristics of the material itself, a restoring force that always tries to return to its original state acts and tends to peel off from the inner peripheral surface of the end of the unit, and there is a gap G between the unit and the unit where this separation occurs.
This may cause a decrease in sealing performance.

In this way, when the seal material itself is deformed to form a seal, wrinkles 9 will inevitably occur at the corners as described above, and if you try to prevent seal leakage due to this 119, there will be troublesome accompanying wrinkles. This requires a lot of work, and also requires a laborious installation work. especially,
This packing work is carried out in a small and dark place under the instrument panel of the vehicle, which makes the work extremely troublesome and disadvantageous in terms of cost.

Moreover, in order to make the packing material itself without wrinkles 9, it must be formed by punching out a material such as foamed urethane, but if this method is used, a large amount of waste material is generated after punching, and the material cost is reduced. It is disadvantageous in terms of bulk and cost. It is also possible to prevent the formation of wrinkles 9 by forming notches in advance at the corners of the long cord-shaped material.
This is different for each unit that should be equipped with this packing,
Patsukin will lack versatility.

Furthermore, when the foamed urethane is used as a packing material, it is necessary to form a so-called skin layer on the surface to prevent air from passing through and improve sealing performance.
When forming this skin layer, there is also the drawback that some kind of treatment must be performed on the surface of the packing material.

The present inventors have found that when molding a packing, if they are molded integrally in a mold, it is possible to easily mold a package that matches each of the various units, and if they are foam-molded in this mold, the above-mentioned results can be achieved. Since the skin layer is also formed on the part that comes into contact with the mold, the present invention was completed by focusing on the fact that it is possible to obtain a packing with extremely high sealing properties.

An object of the present invention is to provide a method for manufacturing a sealing packing that has excellent airtightness and waterproofing properties, is difficult to peel off during handling, is highly versatile, and is inexpensive to manufacture. purpose.

Composition of ER Light (Means for Solving Problems) In order to achieve the above-mentioned object, the present invention provides a method for manufacturing a sealing gasket interposed between each unit of an air conditioner for an automobile. A stock solution is injected into an annular cavity formed in either one of a pair of molds that are spaced relatively close to each other, and this stock solution is foamed within the mold, thereby forming a skin layer on the surface and forming the seal. It is characterized in that the gasket is integrally formed.

(Function) In this way, when the material is foam-molded in the mold, the material will come into contact with the smooth mold surface, and a skin layer will be formed on the surface, causing fine pores to form. Furthermore, since this sealing packing is molded into a predetermined shape in a mold, there are no wrinkles or wasted material like with conventional sealing packings. This means that a gasket with high sealing properties that fits the specified unit can be obtained without any problems.Moreover, when it is attached to the unit, handling and workability are improved, and it can be easily molded, resulting in a significant reduction in manufacturing costs. It will be reduced.

(Example) Hereinafter, an example according to the present invention will be described in detail based on the drawings.

FIG. 1 is a sectional view showing a method of manufacturing a sealing packing according to an embodiment of the present invention, and FIG. 2 is a perspective view of a sealing packing according to the same embodiment, and the members are the same as those shown in FIGS. 5 to 8. The same reference numerals are given to the members.

As shown in FIG. 1, in this embodiment, a pair of upper and lower molds 1
A predetermined cavity 12 is formed in either one of the holes 0 and 11, and a nozzle 14 for injecting the foaming stock solution 13 is formed on the side opposite to this cavity 12. A foaming stock solution 13 is previously loaded into the cavity 12 through the nozzle 14, and foamed by heating or chemical reaction to integrally mold a sealing gasket P having a predetermined shape to match a predetermined unit.

That is, in this embodiment, first, an upper mold 10 having a flat mold surface 10a and a lower mold 11 having a cavity 12 of a size matching the flange of the unit are made to match.

Next, a foaming stock solution in which a foaming material is mixed into a foam is charged into the cavity 12 through a nozzle 14 .

Examples of this foam include rubber materials such as ethylene-propylene rubber (EPDM) and styrene rubber (SB
R>, butadiene rubber (BR), nitrile rubber (NBR
>, and blowing agents such as pentane and hexane.

The stock solution is foamed in this cavity 12, but various foaming conditions in this case affect the foaming ratio of the finished product and greatly affect various properties such as elasticity of the product.
It is necessary to make an appropriate decision depending on the nature of the product you are trying to obtain.

When the stock solution is foamed in the cavity 12 in this way, the air bubbles in the portions that are in contact with the molds 10 and 11 become fine and dense, resulting in a smooth skin layer with almost no holes in the outer peripheral portion 15. This means that it is possible to form a sealing gasket P covered with .

In addition, when integrally molding within this mold, the
If the 7-shaped protrusion 16 is formed on the surface of the sealing gasket P that comes into contact with the mating flange so as to have a cross-sectional shape as shown in FIG. In other words, as shown in Fig. 4, when one side of this sealing gasket P is attached to one flange f using double-sided tape 17, etc., the part that contacts the other 7 flange f is the protrusion of the sealing gasket. Therefore, this sealing gasket P and the other flange f form a line contact that provides reliable sealing performance, and the sealing performance between both units is further improved.

However, the cross-sectional shape of this sealing gasket P is not only rectangular or semicircular as described above, but also M as shown in Fig. 3<C>.
If it is shaped like a letter, two parts having the function of the protrusions 16 can be formed, and the sealing performance will be greatly improved.

Next, the foamed material in the molds 10 and 11 is taken out after releasing both molds using an ejector pin 18 or the like, but a lubricant such as silicone is applied to the sealing gasket P using a coating device or the like.
If it is applied to the outer circumferential surface 15 of , even better sealing properties can be obtained.

The sealing gasket P manufactured in this way is
As shown in the figure, it is attached to the flange f of the cooler unit 2, and the cooler unit 2 is attached to the intake unit 1.
and heater unit 3. In this case, the sealing gasket P has a skin layer formed on its surface and is coated with lubricant, so the surface of the sealing gasket P is as smooth as if it were substantially free of holes. Since it has a smooth surface, it can be quickly inserted between both units, which improves the ease of mounting, improves sealing performance, and improves water resistance.

In particular, when attaching this sealing gasket P to the flange f of the cooler unit 2, there is no bending process like in the past, so wrinkles 9 do not occur in this sealing gasket, and the sealing performance is also reduced. This also eliminates the need for work to correct the wrinkles 9, significantly simplifying the installation work and making it cost-effective.

Note that the present invention is not limited to the embodiments described above, and can be modified to various shapes such as circular and polygonal.

[Effects of the Invention] As described above, according to the present invention, since the sealing gasket is integrally molded and a skin layer is formed on its surface, it has high airtightness and can be installed in a narrow place. To provide an excellent effect of easily and inexpensively manufacturing a sealing packing with good handling workability without the need for troublesome work of correcting wrinkled parts.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is a perspective view of a sealing packing of the same embodiment, and Fig. 3 (a, b).
, c) is a cross-sectional view of the sealing gasket, FIG. 4 is a cross-sectional view of the main part showing the installation condition of the same sealing gasket, and FIG. 5 is a front view showing the installation condition of a conventional automobile air conditioner. , each a in FIGS. 6 and 7. Figure b is a perspective view of a conventional sealing gasket and an explanatory view showing how it is installed, and FIG. 8 is a sectional view of a main part showing a conventional sealing gasket in an installed state. 10.11... Mold, 12... Cavity, 1
3...Standard solution, 14...Nozzle, 15...
・Surface, 16...Protrusion, 17...Double-sided tape, r...Flange, P...Sealing gasket. Patent applicant: Japan Radiator Co., Ltd. Figure 1 Figure 3 (a) (b) (c) 7 P Figure 5 Figure 7

Claims (1)

[Claims] In a method for manufacturing a sealing packing that is inserted between each unit of an automotive air conditioner, a stock solution is injected into an annular cavity formed in one of a pair of molds that are relatively close to each other. A method for manufacturing a sealing packing, characterized in that the sealing packing is integrally formed while forming a skin layer on the surface by foaming the stock solution in the mold.