JPH0127252B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field to Which the Invention Pertains] The present invention relates to a method of manufacturing an intake manifold for an internal combustion engine, and more particularly to a method of manufacturing a die-cast divided intake manifold by bonding and integrating the same with an adhesive. [Prior Art and Its Problems] An intake manifold for an internal combustion engine is used to distribute and send air-mixed gasoline or gasohol sent from a carburetor to the combustion chamber of an internal combustion engine. The shape of such an intake manifold can take various forms depending on the type and size of the internal combustion engine, one example of which is shown in FIG. That is, FIG. 1 shows a perspective view of an intake manifold for a four-cylinder automobile. The intake manifold 1 includes an installation part 2 for attaching it to a carburetor, a ventilation pipe 3 for distributing mixed gasoline and gasohol sent from the carburetor to each engine block, and an intake manifold.
It consists of a connecting part 4 for attaching the manifold to the engine block, and its form differs depending on, for example, the number of cylinders of the internal combustion engine to be connected. In recent years, this type of intake manifold,
Steel is being replaced with aluminum to reduce weight. When using aluminum alloy,
Die casting methods using shell cores have been frequently used to form the fluid passages of intake manifolds. However, this method of using a shell core requires molding and breaking processes for the shell core before and after the die-casting operation, or the use of the shell core causes an increase in production costs and a roughened product surface. There are other problems. To address these problems, a method has been proposed in which, for example, an intake manifold is made in two parts using a die-casting method, and then bonded and integrated using epoxy resin, but this method has not been put to practical use to date. This is due to the fact that the epoxy resin, which has been widely used in the past, has a short pot life, poor assembly operability for segmented die-cast products, corrosion resistance such as gasoline resistance and gasohol resistance, and impact resistance. This is because the properties such as adhesive properties and adhesive strength did not reach a practical level. Furthermore, the curing temperature of the epoxy resin is also high, causing problems such as material softening and blistering of the die-cast product during the curing process. [Object of the Invention] The object of the present invention is to manufacture an intake manifold that retains the initial characteristics by bonding and integrating divided aluminum die-cast intake manifolds using a sealing composition with a specific composition. The present invention provides a method. [Summary of the Invention] In order to achieve the above-mentioned object, according to the present invention, an aluminum die-cast divided intake manifold is prepared by using 25 to 35 parts by weight of polyamide resin and 5 to 100 parts by weight of inorganic filler to 100 parts by weight of epoxy resin.
It is characterized in that it is bonded and integrated using a sealing adhesive containing parts by weight. [Specific Description of the Invention] The sealing composition used in the present invention is a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a novolac phenol type epoxy resin, and one or two types of these bromine-containing epoxy resins. To 100 parts by weight of the epoxy resin consisting of the above, 5 to 100 parts by weight of one or more of talc, silica, calcium carbonate, titanium oxide, carbon, and fumed silica as inorganic fillers, and 25 parts by weight of polyamide resin. It is made by kneading ~35 parts by weight. Sealing adhesives with such a composition have a long pot life, are paste-like, do not sag, and are less toxic, making them easy to handle.Furthermore, since the curing temperature is low, the product itself does not sag during the adhesive curing process. In addition to preventing deterioration of the mechanical properties of Integrated intake
The manifold fully satisfies the desired characteristics. Furthermore, the number of production steps is reduced and the adhesive curing temperature is low, making it possible to significantly reduce costs compared to conventional manufacturing processes. Conventional heat-resistant epoxy resins are often heat-curable with a long pot life, and resins such as aromatic polyamines are often used, and although they have excellent adhesive strength and mechanical strength, , gasoline resistance,
Gasohol resistance and aging resistance of mechanical properties were not very good, and when applied to adhesion of intake manifolds, the reliability of the joints was sometimes lacking. However, bisphenol A type epoxy resin,
When applying polyamide resin to bisphenol F type epoxy resin, novolak phenol type epoxy resin, and a combination of one or more of these bromine-containing epoxy resins,
The above drawbacks can be avoided. In particular, the epoxy resin has a molecular weight of 300 to 3000, an epoxy equivalent of 150 to 2000, and a hydroxylation (equ/Kg) of 0.8 to 3.5.
When this is the case, a bonded portion with extremely excellent properties is formed. Epoxy resin is cured only by adding a curing agent, and in the case of the present invention, 25 to 35 parts by weight of polyamide resin is added. That is, when used in a mass production process such as the process of the present invention and where high bonding accuracy is required, a relatively long pot life and a short complete curing time are required. As polyamide resins used as this type of curing agent, polyamide amines prepared by reacting linolenic acid dimers with excess polyalkylene polyamines and aromatic modified polyamide amines are suitable;
When the amount added is less than 25 parts by weight, the pot life is 120%.
If the amount exceeds 35 parts by weight, the pot life will be less than 90 minutes, which is not preferable. Furthermore, since the intake manifold manufactured according to the present invention comes into contact with gasoline, gasohol, etc., the sealing composition is required to have durability against them. Polyamide amine is suitable as a polyamide resin that can sufficiently withstand these demands, and particularly polyamide amine produced by reacting a dimer of linolenic acid with an excess of polyalkylene polyamine is most suitable. This type of polyamide amine has a viscosity of
Those having an amine value of about 445 at 2,000 to 5,000 cps (25° C.) are preferable, and when these are used, various properties required both during adhesion and during use are satisfied. Furthermore, the inorganic filler is added to adjust the viscosity of the sealing adhesive to improve adhesive workability, as well as to improve heat resistance and shear adhesive strength. Inorganic fillers used for this purpose are talc,
It is composed of one or more of silica, calcium carbonate, titanium oxide, carbon, and fumed silica, and contains 5 to 100 parts by weight of epoxy resin.
Added in parts by weight. When it is in this addition range, the viscosity is in the range of 5,000 to 400,000 cps, and the above-mentioned desired characteristics can be satisfied. Further, the particle size of the filler is preferably 50 μm or less, preferably 0.01 to 30 μm. Epoxy resins and polyamide resins containing these inorganic fillers are stored separately before use, and after being degassed under vacuum, the two are sufficiently kneaded at room temperature and used by applying it to the joint surface within the pot life. be done. The present invention uses a sealing composition having the composition described above to bond and integrate divided aluminum die-cast intake manifolds. The applied aluminum material is appropriately selected from ADC1 alloy to ADC12 alloy, which are general-purpose die-casting alloys, depending on the desired properties, but special aluminum alloys such as iron 1.4 to 2.2% by weight and manganese 0.05 to 0.8% by weight are used. This does not preclude the application of aluminum alloys etc. whose main additive component is ADC12 alloy, and it can be said that ADC12 alloy is usually preferable in terms of cost. On the other hand, die casting methods include ordinary die casting method,
There are low-speed die-casting methods, including the Achillad method, and non-porous die-casting methods, and non-porous die-casting methods include vacuum die-casting methods, oxygen-substituted die-casting methods, atmosphere fluidized die-casting methods, and combinations of these methods. However, in the case of the present invention, it may be manufactured by any of these methods. These methods involve supplying molten aluminum alloy at 640 to 750°C to a mold with a pressure of 400 to 1000 kg/cm ² and solidifying it under pressure. and then split the intake manifold at the appropriate location, preferably in two.
The divided intake manifold applied to the present invention is manufactured by dividing the intake manifold, manufacturing molds according to the number of divisions, and performing die-casting operations according to the number of divisions. By dividing in this way, it becomes unnecessary to use a shell core, and it becomes possible to fully exhibit the characteristics of a die-cast product. That is, (1) sufficient pressure can be applied without worrying about core collapse, so thin products can be produced with high yield. (2) Since no core is used, the inner surface of the ventilation tube has excellent smoothness, which lowers the flow resistance of the passing gas. (3) Since the process is simplified and simplified, productivity can be increased and production costs can be reduced. Benefits such as this will be demonstrated. In addition, if desired, such a split intake/
When manufacturing the manifold, auxiliary means such as simultaneously forming an uneven fitting joint structure on the joint surface to improve the joint strength may also be applied. The divided intake manifold manufactured in this manner is subjected to surface purification treatment using caustic soda, an organic solvent, etc. for the purpose of removing an oxide film and degreasing the joint surface as a pretreatment before joining. At this time, if desired, the joint surface may be roughened by chemical or mechanical means in order to improve the joint strength. Next, a specific manufacturing method of the present invention will be explained based on the example illustrated in FIG. 2, but the method is not limited thereto. For example, the intake manifold can take on various external shapes depending on the type of internal combustion engine, and the split position can be shifted to the optimal position accordingly, and as shown in the example, the split planes can all be on the same horizontal plane. In addition to the case where the image is divided into two, it is also possible to use a method of dividing the image in stages. Fig. 2 shows an example of an embodiment in which the intake manifold for a four-cylinder automobile illustrated in Fig. 1 is made into two die-cast parts, which are then glued and integrated. . Two divided intake manifolds 1' and 1'' whose surfaces have been subjected to surface purification treatment after die casting are prepared, and a sealing composition 6 is applied to the joint surface 5 of one or both of them. The sealing composition 6 can be applied to the joint surface by continuously kneading each component at room temperature using a coating gun that also has a kneading function, or by applying it to the joint surface by kneading it in advance in a mixing tank. The coating can be applied by any appropriate means such as a discharge nozzle type coating gun, a roll transfer type coating gun, a manual coating gun, or an automatic coating robot gun. In addition, when kneading and preparing in advance, it is necessary to complete use within the pot life (90 to 120 minutes). The width of the joint surface is 2.5 mm or more, preferably 3 to 5 mm.
However, the sealing composition is applied to this joint surface in the form of a bead of approximately 2 mm diameter. After application, the divided intake manifold is assembled and fixed in a predetermined shape using a fixing jig, and then In order to accelerate the curing of the sealing composition and complete the adhesion in a short time, it is carried into a heating furnace. For heating, an appropriate heating furnace such as a hot air circulation drying oven is used, and the assembly is heated at 70 to 100°C for 1 to 3 seconds.
The curing reaction of the sealing composition is accelerated by heating for a certain period of time, and an adhesive layer 7 having the desired properties is formed, resulting in a completed intake manifold that is firmly bonded and integrated as shown in FIG. It will be done. When the method of the present invention is used, the number of production steps is reduced compared to the conventional method, so the product can be supplied at low production cost, and the product quality can be comparable to that of the conventional method. Example 1 As an epoxy resin composition, bisphenol A
100 parts by weight of type epoxy resin (trade name: Epicote 828, manufactured by Ciel), talc with an average particle size of 1 to 5 μm
60 parts by weight and 2 parts by weight of fumed silica with an average particle size of 0.01 to 0.04 μm were kneaded to form a putty with a specific gravity of 1.50, and on the other hand, polyamide amine (product name: Tomide 246, Fuji Kasei Co., Ltd.) with a specific gravity of 1.01 and a viscosity of 3000 cps was kneaded. made)
per 100 parts by weight of the epoxy resin composition.
Applying 32.4 parts by weight while kneading just before bonding (two-component mixed air coating gun manufactured by ThreeBond)
supplied. On the other hand, silicon 11.3% by weight, copper 2.5% by weight, iron 0.4%
Clamping force of aluminum alloy equivalent to ADC-12 alloy whose main component is % by weight at a casting temperature of 700℃.
2nd 500t cold chamber die casting machine
A two-part molded body of an intake manifold as shown in Figures a and b was obtained. The total weight of this two-part molded product is 1450g, which is about 20% heavier than the one cast in one piece using a shell core.
% weight reduction, and the inner surface of the vent pipe and the joint surface of the divided molded body were extremely smooth. Next, the joint surfaces (width 4 mm) were sandblasted and then cleaned with an organic solvent. A sealing composition was applied with a bead of 2 mm diameter to one of the joint surfaces of the two-part molded body prepared in this way, and both the divided molded bodies were assembled and fixed with a jig, and then transported to a continuous belt conveyor type drying oven. The adhesive work was completed by heating at 75°C for 2 hours. Evaluation tests were conducted on the intake manifold manufactured in this way, and the results are shown in the table below.

[Table] In the above accelerated test, if the shear strength after immersion in gasohol is 50Kg/cm ² /500hr or more and the gasohol weight change +20% /500hr or less, there is no practical problem, so the product is manufactured according to the present invention. It can be seen that the intake manifold developed has sufficient characteristics for practical use. Comparative Example 1 A performance comparison was made with a conventional epoxy resin adhesive, and the results are shown below. The composition of the material used in the comparative test is as follows.

[Table] Using a sealing composition consisting of these compositions,
A divided intake manifold manufactured under the same conditions as in Example 1 was coated in a bead shape of 2 mmφ, and an evaluation test was conducted. The results are shown in the table below.

〔Effect of the invention〕

By using a sealing composition with a specific composition, the present invention can develop properties that are difficult to achieve with conventional epoxy resin adhesives.
We have succeeded in satisfying the necessary joint characteristics, and when molding the split intake manifold, we are able to mold it under conditions that allow sufficient pressurizing force of the die-casting to be applied, making it possible to achieve excellent product quality and sealing. Because the curing temperature of the composition for
To provide an intake manifold with extremely excellent properties, such as bonding work being performed at a lower curing temperature than conventional ones, and preventing deterioration of mechanical properties due to the intake manifold itself being heated to the curing temperature. is possible.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an intake manifold shown as an embodiment of the present invention, and FIG.
2A and 2B are perspective views of the intake manifold shown in FIG. 1 divided into two parts. 1...Intake manifold, 1', 1''...
...Split intake manifold, 2...Carburetor installation part, 3...Vent pipe, 4...Engine block connection part, 7...Adhesive layer.

Claims (1)

[Claims] 1 Aluminum die-cast split intake
The manifold is made of 25 to 35 parts by weight of polyamide resin and 5 parts by weight of inorganic filler per 100 parts by weight of epoxy resin.
The epoxy resin is characterized in that the epoxy resin is a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a novolac phenol type epoxy resin. The polyamide resin is composed of a resin and one or more of these bromine-containing epoxy resins, and the polyamide resin is a polyamide amine and an aromatic modified polyamide obtained by reacting a linolenic acid dimer with an excess polyalkylene polyamine. A method for producing an intake manifold characterized by being an amine. 2. The manufacturing method according to claim 1, wherein the inorganic filler is comprised of one or more of talc, silica, calcium carbonate, titanium oxide, carbon, and fumed silica.