JPH01295078A - Manufacture for gasket compound material - Google Patents

Abstract

PURPOSE:To contrive the improvement of dimensional accuracy of a gasket by injecting hardening expansion liquid-state resin into a gasket molding groove and coating the upper of the resin with a gasket-coated coating part being forced to adhered. CONSTITUTION:A gasket forming mold 1 provides in a bottom surface 3 of its hollow part 2 a gasket molding groove 4 to be engraved, and hardening expansion liquid-state resin 5 is injected into this gasket molding groove 4. A coating part 7 to coat a gasket covers the upper of the gasket molding groove 4 injecting the hardening expansion liquid-state resin 5, and it is hardened and expanded while forcing the coating part to adhere. The resin 5 is adhesively attached not to a surface of the gasket molding groove 4 but selectively only to the coating part 7, after the mold is released, a gasket compound material A, integrally forming a gasket with the coating part 7, is formed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to vehicle parts such as cylinder heads and oil pans;
A method of bonding gaskets to various adherend parts that require connection to other parts via gaskets, such as electrical parts such as motor housings, and manufacturing gasket composites in which the gas get and adherend parts are integrated. In particular, the present invention relates to a method of manufacturing a gasket composite having good dimensional accuracy and no voids or voids.

[Conventional technology]

Various vehicle parts, such as cylinder heads, oil pans,
Various parts such as instrument covers, intake manifolds, exhaust manifolds, etc., or various electrical parts such as floppy disks and motor housings need to be connected to other parts via gaskets. Gasket composites have been developed in which a roughened gasket layer is adhered to the adhered part (hereinafter referred to as the adhered part).

As a method for manufacturing this type of gasket composite, a method is conventionally known in which a liquid gasket material is printed on a part to which a gasket is to be attached by screen printing to form a gas get on the part. (Tokuko Sho 43-472
(See Publication No. 7).

In addition, apply liquid sealant to the flange surface of the adhered parts.
There is also known a method in which the adhesive is cured after being applied by a method such as the following.

Furthermore, a method of forming a gasket layer on an adhered part by injection molding is also known.

Furthermore, a method has been proposed in which a liquid resin is applied to the part to be molded, and the resin is covered with a mold and cured. (
(Refer to Japanese Patent Application Publication No. 60-237267).

[Problem that the invention seeks to solve]

However, the first method described above has limitations such as the inability to provide a large thickness of the gasket layer and the need for the gasket-adhering surface of the adhered part to be flat.

Furthermore, the second method has problems with the accuracy of the joining portion of the coating beads and the dimensional accuracy of the beads.

Furthermore, although the third method has excellent dimensional accuracy and mass production, the mold cost is high, it is not suitable for low-volume, high-mix production, and the mold clamping force is strong, so it is difficult to use with weak adherent parts or damage. It is not suitable for molding easy parts. Furthermore, this method has the problem of release from the mold, and there is also the problem that it is difficult to integrate the gasket and the adherend component by adhesion.

Next, the fourth method has the disadvantage that air pockets are likely to be formed in the cavity when the covering mold is covered, and furthermore, the liquid resin is likely to overflow and cause cracks.

Therefore, the purpose of the present invention is to improve the dimensional accuracy of the gasket.
Another object of the present invention is to provide a method for producing a gasket composite which is free from voids and voids and which improves the drawbacks of the above-mentioned known techniques.

[Means for solving problems]

In order to achieve the above-mentioned object, according to the present invention, a cured expandable liquid resin is injected into a gas get molding groove formed in a gas get mold, and a part to be covered with a gasket is covered thereon. After covering and crimping, the resin is cured and expanded and adhered to the adhered part to obtain a gasket composite in which the gasket and the adhered part are integrated.

Hereinafter, the present invention will be explained in detail using the accompanying drawings.

1, 2, and 3 are process diagrams showing one step of the method of the present invention, and as shown in FIG. 1, the bottom surface 3 of the hollow part 2 of the gasket mold l has a gasket A forming groove 4 is cut into the gasket forming groove 4, and a cured expandable liquid resin 5 is injected into the gasket forming groove 4 through a discharge nozzle 6 by handling or by automatic operation using a robot or the like. At least the part of the gasket mold 1 that comes into contact with the resin 5 is made of a material that has release properties from the resin 5, such as Teflon or silicone resin. It is formed by applying a molding agent and performing a mold release process.

Further, the amount of surface resin 5 injected into the gasket forming groove 4 is an amount smaller than the depth of the gasket forming groove 4 and higher than the depth of the gasket forming groove 4 after curing and expansion.

To express this concretely, if the volume of the liquid resin 5 after curing and expansion is 1, and the volume of gasket molding/1% 4 is vo, then V + /V o ” 1,05~5,0
) Range.

It is preferable that it be within. If this is smaller than 1.05, the cured product may not reach the adhered part after curing and expansion, or air venting may not be performed sufficiently, leading to the possibility that voids may occur. On the other hand, if it is larger than 5.0, the pressure in the pig's intestine will increase, making it necessary to increase the pressing force of the torn article more than necessary, and furthermore, the liquid resin will spill out and flakes are likely to occur.

Next, in the present invention, as shown in FIGS. 2 and 3, a part 7 to be covered with a gasket is placed on the gas get molding groove 4 into which the cured expandable liquid resin 5 has been injected as described above. is covered, and the cured expandable liquid resin 5 is cured and expanded while being pressed by a pressurizing ram 9 via a press plate 8. The pressing force at this time is several kgf/several hundred kgf. In addition, when heat and pressure are required to cure the resin 5, the heat and pressure is applied using a press plate 8 having a built-in heater 10. The resin 5 may be heated from the side of the gasket mold 1 using the built-in mold 1, or it may be heated by induction, dielectric, ultrasonic heating, etc., or the entire resin 5 may be heated in a heating furnace. You can also heat it by putting it in.

At this time, as shown in FIG. 4(a), the amount of resin 5 is initially smaller than the depth hl of the gasket molding groove 4, for example, the height h2, but as shown in FIG. 4(b). As shown, the adhered part 7 is placed over the gasket molding/lI4, and the part 7 is heated and pressed in the direction of the arrow by applying pressure from above with the built-in blur 2 of the heater 10, and then the resin 5 is hardened. It expands in the direction of the arrow while expelling the air in the gasket forming groove 4, and finally the depth hl of the gasket forming groove 4 increases as shown in FIG. 4(C).
It hardens and expands to a height higher than that, contacts the adherend part 7, and adheres. At this time, the resin 5 does not adhere to the surface of the gas get molding groove 4, but selectively adheres only to the adhered part 7, and after demolding, as shown in the fifth figure, the resin 5 is bonded to the adhered part 7.
forming an integrated gasket composite A.

In addition, as shown in FIG. 4(d), the contact portion of the adhered part 7 with the resin 5 may have a concave shape; in this case,
As described above, the resin 5 expands while expelling air, and eventually comes into contact with and adheres to the bottom surface 7a of the recess.

In addition, in the gasket composite A between the fifth gap and the gasket 5a, in order to prevent the adhesive portion 11 between the gasket 5a and the adhered member 7 from popping out, a gasket is formed on the boundary portion 11 as shown in FIG. A protrusion 12 is formed from the bottom surface 3 of the mold 1, and the protrusion 12 is inserted into the adherend part 7 during molding, or as shown in FIG.
A soft packing 13 made of a soft material with mold releasability such as Teflon or silicone is sandwiched and molded, and as shown in FIG. Even if a grooved material 4 having a U-shaped cross section with a height slightly higher than the depth of the gasket molding groove 4 is fitted into the gasket molding groove 4 and molded with the tip 15 slightly protruding from the bottom surface 3. good.

The gasket composite A of the present invention obtained as described above can be molded into any shape by arbitrarily selecting the shape of the gasket molding groove 4, for example, as shown in FIGS. 9(a) and (b).
, (c), and (d).

Further, the cured expandable liquid resin 5 used in the present invention is in a liquid state when press-fitted into the gasket molding groove 4, and expands during curing to increase its volume. Liquid silicone rubber produced by peroxide crosslinking reaction, urethane resin, epoxy resin, nylon, phenol resin, resin for RIM (reaction injection molding) such as polybutadiene, plastisol made into a liquid by mixing resin powder and a softening agent, and other polysulfides. , reactive liquid rubbers such as polyacrylic urethane, polyacrylonitrile butadiene copolymer, curable resins, etc.
Examples of means for expanding the volume during curing include adding a foaming agent, adding solvent microcapsules, generating gas as a reaction product, mixing gas and solvent, and expanding by heating.

Examples of the blowing agent include inorganic blowing agents such as sodium bicarbonate and zinc bicarbonate, and organic blowing agents such as N,N'-dinitrosopentane methylenetetramine and azocarbonamide. The amount is 0.1 to 40 parts by weight per 100 parts by weight of the liquid resin; if it is less than 0.1 part by weight, a sufficient expansion effect cannot be obtained, and if it is more than 40 parts by weight, the physical properties of the cured product will be significantly impaired. There is a risk. In addition, examples of solvent microcapsules include those with a particle size of several microns to several hundred microns, in which a low-boiling point solvent such as alcohol is wrapped in a shell wall such as vinylidene chloride. Matsumoto Microsphere-F-
30, F-50J, etc. The amount added is the same as that of the foaming agent.

For example, in the case of silicone resin, a method for generating gas as a reaction product is to dehydrogenate siloxane with hydrogen groups and siloxane with silanol stores in the presence of an acid, an alkaline earth metal compound, a platinum-based catalyst, etc. A condensation reaction is carried out, and the generated hydrogen gas is used. In the case of urethane resin, an isocyanate group and water are reacted, and carbon dioxide gas generated is used.

Examples of methods of mixing gases and solvents and expanding them by heating include fluorinated hydrocarbons (perfluorocyclobutane, perfluoropropane, chlorohexafluoropropane, etc.), hydrocarbons such as propane, butane, pentane, hexane, and alcohol. esters, ethers,
Ketones, halogenated hydrocarbons, N2.0! , CO2 and other gases alone or as a mixture of multiple types are dissolved in a liquid resin, or by forcibly stirring and mixing.
Next, by heating the liquid resin mixed with this gas, gas is generated and the liquid resin is expanded.

The amount of gas added at this time is the same as that of the foaming agent.

[Effect]

The sealing performance of the gasket composite according to the present invention is achieved through a correlation with the pressure of the adhered parts, which is extremely low compared to the mold clamping force of conventional injection molding, RIM molding, and LIM molding. fully achieved. In other words, the mold clamping force for normal injection molding is: mold clamping force (k+rf) - projected area [-] x effective injection pressure (
kgf/c111), and even making small parts requires a mold clamping force of several 10 or more.

In contrast, in the present invention, the following formula is sufficient: crimping force (kgf) = projected area [d] x pig intestinal pressure of liquid resin (kgf/all), and by adjusting the initial filling amount and expansion rate of liquid resin. It is possible to mold with a low pressure force of several kg (~several hundred kg) at one end.

Furthermore, the mold used in the present invention has a simple structure and does not require much higher accuracy and strength than ordinary injection molding, and is therefore suitable for high-mix, low-volume production.

Furthermore, according to the present invention, it is possible to form three-dimensional adherend parts having some protrusions, which was impossible with conventional screen printing.

[Example of real s’]

Hereinafter, the present invention will be explained in detail with reference to Examples.

As a gasket mold having the shape shown in Figure 1, the hardness is D7.
5. Elongation 400%, tensile strength 43Qkg f/cd
(Use a D fluororesin mold with a gasket molding groove of 2 x 2 groove cross section, and apply 1.2 m of liquid resin (U-1, U-2) shown in Table 1 to this molding groove. - Inject by robot from the discharge nozzle of the nozzle diameter. Immediately after injection, JIS G3141 cold rolling mouth plate (40
tm) iron plate was covered from above as shown in the second figure, and heating and pressure were applied to expand and harden the liquid resin in the molding groove.

Table 2 shows various conditions and test results at this time.

・／　・ / /′ / / /′ / Table-11 Quantity g.

In Table 2, the pressure resistance test was carried out by covering the obtained composite with an acrylic plate, tightening it four times with four M8 bolts, applying a pressure of 30 ON water column and holding it for 5 minutes, and leakage clearly occurred. This was determined by visual observation. The adhesion test was conducted by pinching the gas get layer with fingertips and observing whether it would peel off when pulled lightly.

From Table 2, Examples 1 to 4 according to the present invention showed good results in all tests, but the injection volume ratio was 4.0%.
It was found that Comparative Example 1, which had a low adhesive strength, had poor adhesion and leakage and voids occurred, and Comparative Example 2, which had a low pressure bonding force, had a significant occurrence of flaking.

Tests were conducted in the same manner as in Examples 1 to 4, except that the resin shown in Table 3 was used instead of the liquid resin shown in Table 1, and the conditions and test results are shown in Table 4.

In Table 3, rKE1830J is a self-adhesive silicone elastomer manufactured by Shin-Etsu Chemical Co., Ltd.
0J is a solvent microcapsule manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.

Table 3 Table 4 Table 4 shows that Examples 5 to 9 according to the present invention all showed good results in various tests.

〔Effect of the invention〕

As described above, according to the method of the present invention, it is possible to easily and reliably mold a gasket composite that does not generate voids or flakes and has good adhesion using a simple mold and with extremely low pressure bonding force. can do.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a specific example of a gas mold and a mold according to the present invention, and an explanatory diagram showing one step of the present invention, and FIGS. 2 and 3 each illustrate the method of the present invention. 4(a), (b), (c).
, (d) are cross-sectional views showing the cured and expanded state of the liquid resin according to the present invention, FIG. 5 is a perspective view of a specific example of a gasket composite obtained by the method of the present invention, and FIG. , FIG. 7, and FIG. 8 are sectional views showing preferred specific examples of the stopper for preventing cracks, extrusion, etc., respectively, and FIGS. 9(a), (b), (c), and (d) are respectively FIG. 3 is a cross-sectional view showing the shape of a gasket layer. DESCRIPTION OF SYMBOLS 1... Gasket mold, 4... Gasket forming groove, 5... Cured expandable liquid resin, 7... Adhered parts, A
...Gasket complex. Patent applicant ThreeBond Co., Ltd. Agent Patent attorney Hitoshi Someya, □ 7th each (d) Reader 5th circle 9th (, Q)

Claims (4)

[Claims] (1) Inject a cured expandable liquid resin into the gasket molding groove formed in the gasket mold, cover the part to be covered with the gasket and press it, and then harden and expand the resin. A method for producing a gasket composite, which comprises adhering to the adhered part to obtain a gasket composite in which the gasket and the adhered part are integrated. (2) In the method according to claim 1, the amount of the cured expandable liquid resin injected is smaller than the depth of the gasket forming groove, and is higher than the depth of the gasket forming groove after curing and expansion. A method of manufacturing a gasket composite in a quantity of (3) In the method according to claim 2, the injection amount of the cured expandable liquid resin is such that the volume of the liquid resin after cure and expansion is V_1, and the volume of the gasket forming groove is V_1.
A method for manufacturing a gasket composite in which V_1/V_0 is within the range of 1.05 to 5.0 when V_1/V_0 is 0. (4) The method of manufacturing a gasket composite according to claim 1, wherein the pressure force is within a range of several kgf to several hundred kgf.