JP2003184677A - Manifold and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manifold integrated with a gasket capable of holding stable sealing performance for a long time, and a manufacturing method thereof. <P>SOLUTION: In this manifold 1, a gasket 4 for preventing leakage of fluid is integrated with an attachment face 2b of an attachment base 2 to an engine, and an elastic tubular part 3 is formed by an alloy of nitrile rubber and polyvinyl chloride. The gasket 4 is formed of one selected from a group of hydrogenation nitrile rubber, fluorine rubber and epichlorohydine rubber. According to a manufacturing method of the manifold 1, after unvulcanized rubber for a gasket is attached to a portion of the attachment base 2, to which the gasket 4 is formed, the attachment base 2 and the unvulcanized rubber for a gasket are set to a cavity C of a molding die M. Thereafter, an elastic tubular forming part Cp of the cavity C is filled with the unvulcanized rubber for the elastic tubular part. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manifold for connecting an engine and a carburetor and a method for manufacturing the manifold.

[0002]

2. Description of the Related Art Generally, in an intake system of an engine, for example, a two-cycle engine or a four-cycle engine, a manifold is used as a connecting means for connecting an intake pipe of the engine and a carburetor.

Such a manifold has a flow passage formed inside thereof through which the air-fuel mixture supplied from the carburetor toward the engine passes, and is connected to a mounting base connected to the engine and the carburetor. The elastic tubular portion is integrated. The mounting base is made of metal or resin, and the elastic tubular portion is made of a rubber-like elastic body exhibiting rubber elasticity. In addition, for the manifold, for example, an attachment base coated with an adhesive is set in a cavity of a molding die, and unvulcanized rubber for an elastic tubular portion for molding the elastic tubular portion is filled, By applying heat and pressure of a predetermined temperature to the elastic tubular portion unvulcanized rubber for a predetermined time, vulcanization of the elastic tubular portion unvulcanized rubber,
A manufacturing method in which the mounting substrate and the elastic tubular portion are bonded together by vulcanization bonding, which allows simultaneous bonding, is generally used.

[0004]

When assembling a conventional manifold to an engine, between the manifold and the engine, more specifically, between the mounting surface of the mounting base of the manifold and the manifold mounting surface of the engine,
A separate gasket is required as a sealing device for preventing the air-fuel mixture passing through the flow path of the manifold from leaking to the outside, and this gasket is formed of a rubber-like elastic body exhibiting rubber elasticity, for example, rubber. O-rings are commonly used. When such a gasket is used, when assembling the manifold to the engine,
There are problems that the gasket may come off, and that the number of parts used may increase due to the use of the gasket, resulting in complicated assembly work.

As one method for coping with such a problem, there has been proposed a structure in which a protrusion serving as a gasket is integrated with a mounting surface of a mounting base of a manifold.

However, in the conventional manifold integrated with a gasket, since the material of the gasket and the material of the elastic tubular portion are made of the same material, that is, the resistance to fuel oil required for the gasket and high temperature Since the material with excellent compression set and the material with excellent fuel oil resistance and ozone resistance required for the elastic tubular part are integrated in the same material, there is no problem in fuel oil resistance, but gasket If the elastic tubular part and the elastic tubular part are integrated with the material used for the gasket, there is a problem that the ozone resistance of the elastic tubular part is inferior and ozone cracks occur. Therefore, the gasket and the elastic tubular part are used for the elastic tubular part. When the materials are integrated, the compression set at high temperature of the gasket is inferior and stable sealing performance cannot be maintained for a long period of time. There is a problem to say.

The present invention has been made in view of these points, and has integrated a gasket capable of maintaining stable sealing performance without causing ozone cracks in the elastic cylindrical portion for a long period of time. An object of the present invention is to provide a manifold and a manufacturing method thereof.

[0008]

In order to achieve the above-mentioned object, the features of the manifold of the present invention are that a flow passage is formed inside, a mounting base body connected to an engine, and an elastic tubular shape connected to a carburetor. In the manifold in which the parts are integrated, a gasket that prevents fluid leakage is integrated on the mounting surface of the mounting base with the engine, and the material of the elastic tubular part is made of nitrile rubber and polyvinyl chloride. Alloy, the material of the gasket is hydrogenated nitrile rubber,
It is one selected from the group consisting of fluororubber and epichlorohydrin rubber. And, by adopting such a configuration, the alloy of nitrile rubber and polyvinyl chloride easily and reliably imparts excellent fuel oil resistance and ozone resistance properties to the elastic tubular portion,
One selected from the group consisting of hydrogenated nitrile rubber, fluorine rubber, and epichlorohydrin rubber is one that ensures excellent fuel oil resistance to gaskets, good compression set at high temperatures, and heat resistance. Can be given. Therefore, while preventing the occurrence of ozone cracks in the elastic tubular portion, on the mounting surface of the mounting base with the engine,
It is possible to easily integrate a gasket that maintains stable sealing performance for a long period of time and prevents fluid leakage.

The feature of the method for manufacturing a manifold of the present invention is that after mounting the unvulcanized rubber for the gasket on the gasket forming portion of the mounting base, the mounting base and the unvulcanized rubber for the gasket are set in the cavity of the molding die. Then, after that, the elastic tubular portion forming portion of the cavity is filled with the unvulcanized rubber for the elastic tubular portion. By adopting such a configuration, the elastic tubular portion and the gasket can be easily integrated with the mounting base, and the elastic tubular portion and the gasket are formed of materials optimal for their respective characteristics. In addition, the material used for the gasket can be suppressed to the amount necessary for forming the gasket.

Another method for manufacturing a manifold according to the present invention is
Set the mounting base in the cavity of the molding die, then
The elastic tubular portion forming portion of the cavity of the molding die is filled with the unvulcanized rubber for the elastic tubular portion, and the gasket forming portion of the cavity is filled with the unvulcanized rubber for gasket. By adopting such a configuration, the elastic tubular portion and the gasket can be easily integrated with the mounting base, and the elastic tubular portion and the gasket are formed of materials optimal for their respective characteristics. You can
And productivity can be improved.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to the embodiments shown in the drawings.

The manifold of this embodiment is exemplified as one used as a connecting means for connecting an engine intake pipe and a carburetor in an intake system of a four-cycle engine.

As shown in FIGS. 1 and 2, the manifold 1 of this embodiment includes a mounting base 2, an elastic tubular portion 3, and
In addition to having the gasket 4, the elastic tubular portion 3 and the gasket 4 are integrated with the mounting base 2 by a manufacturing method described in detail later.

The mounting base 2 is used for connecting to an engine, more specifically, to an intake pipe of the engine, and is formed in a substantially parallelogram shape in a plane. A central portion inside the mounting base 2 has a thickness direction. An inner hole 2a penetrating therethrough is formed. Further, the mounting surface 2b, which is located on the engine side shown on the right side in FIG.
The surface is formed flat. A gasket installation groove 2c is formed along the inner hole 2a in the vicinity of the inner hole 2a of the mounting surface 2b, as shown in an enlarged view in FIG. Furthermore, in the vicinity of the lower left corner and the upper right corner of the mounting base 2 in FIG. 1, screw insertion holes 2d penetrating in the thickness direction are respectively formed, and the screw insertion holes 2d are provided on the opposite side of the mounting surface 2b. The manifold 1 is fixed to the engine by screwing a manifold fixing screw (not shown) which is inserted from above into the manifold mounting surface of the engine.

As a material for the mounting base 2, a metal, a resin or the like is generally used. The mounting base 2 of this embodiment is formed of aluminum, more specifically, an aluminum alloy for casting.

The elastic tubular portion 3 is mainly used for connecting the manifold 1 and the carburetor, and is formed in a thick-walled tubular shape. The elastic tubular portion 3 is on the right side in FIG. The mounting base 2 is fixed to the end surface on the engine side shown in (1) so that the mounting surface 2b is exposed to the outside.
The inside of the inner hole 3a of the elastic tubular portion 3 is formed as a flow path 5 through which the air-fuel mixture supplied from the vaporizer toward the engine can smoothly pass. The tip of the elastic tubular portion 3 located on the carburetor side shown on the left side of FIG. 2 is an insertion tube 3b for inserting the air supply portion of the carburetor.

As materials for the elastic tubular portion 3 of this embodiment, nitrile rubber (NBR) and polyvinyl chloride (PV) are used.
Alloy with C) is used.

In the gasket 4, the air-fuel mixture that mainly passes through the flow passage 5 inside the manifold 1 is used.
Between the engine and the engine, more specifically, as a sealing device for preventing external leakage from between the mounting surface 2b of the mounting base 2 of the manifold 1 and the manifold mounting surface of the engine. Mounting surface 2b of mounting base 2
It is fixed to the gasket installation groove 2c formed in the. As shown in FIG. 3, the gasket 4 has an annular protrusion 4a that is provided at a central portion in the width direction of the gasket installation groove 2c so as to project in a direction away from the mounting surface 2b.
The top of the protrusion 4a is projected from the mounting surface 2b, and the top of the protrusion 4a is brought into contact with the manifold mounting surface of the engine. In addition, you may form the protrusion 4a in multiple double and triple.

As the material of the gasket 4, one selected from hydrogenated nitrile rubber (HNBR), fluorine rubber (FKM) and epichlorohydrin rubber (CO, ECO) is required for the usage conditions and design concept of the manifold 1. Used accordingly. In other words, one selected from the group consisting of hydrogenated nitrile rubber, fluorine rubber and epichlorohydrin rubber is used.

Next, the operation of this embodiment having the above-mentioned structure will be described.

According to the manifold 1 of the present embodiment, the alloy of nitrile rubber and polyvinyl chloride easily and surely imparts excellent fuel oil resistance and ozone resistance properties to the elastic tubular portion 3. One selected from the group consisting of hydrogenated nitrile rubber, fluoro rubber and epichlorohydrin rubber is one that has excellent fuel oil resistance to the gasket 4, good compression set at high temperature and heat resistance. Can be surely given. That is, different characteristics required for the elastic tubular portion 3 and the gasket 4 can be easily and surely provided. Therefore, the gasket 4 prevents the occurrence of ozone cracks in the elastic tubular portion 3 and maintains stable sealing performance on the mounting surface 2b of the mounting base 2 with the engine for a long period of time to prevent fluid leakage. Can be easily integrated.

Next, a method of manufacturing the manifold 1 of the present embodiment having the above-mentioned structure will be described.

4 to 7 show a first embodiment of the method for manufacturing the manifold 1 of this embodiment. In the manufacturing method of this embodiment, the elastic cylindrical portion 3 and the gasket 4 are integrally molded with the mounting base 2 using the molding die M shown in FIG.

More specifically, this is a material for forming the elastic tubular portion 3 prior to integrally molding the elastic tubular portion 3 and the gasket 4 with the mounting base 2 using the molding die M. Unvulcanized rubber for elastic tubular part and gasket 4
An unvulcanized rubber for a gasket, which is a material for forming the base material, is prepared, and the mounting base 2 is pretreated.

The unvulcanized rubber for the elastic tubular portion is an alloy of nitrile rubber and polyvinyl chloride. The unvulcanized rubber for the elastic tubular portion is prepared by using nitrile rubber and polychlorinated rubber as raw rubbers. It is carried out by adding a predetermined amount of compounding chemicals such as a vulcanizing agent and various fillers to an alloy with vinyl and kneading with a mixer such as an open roll or a Banbury mixer.

The unvulcanized rubber for the gasket is selected from hydrogenated nitrile rubber (HNBR), fluorine rubber (FKM) and epichlorohydrin rubber (CO, ECO). And the preparation of unvulcanized rubber for gaskets,
It is carried out by adding a predetermined amount of a compounding chemical such as a vulcanizing agent and various fillers to the raw material rubber and kneading the mixture with a mixer such as an open roll or a Banbury mixer. Also,
The unvulcanized rubber for gaskets that has been kneaded is formed into a string shape having a thickness that sufficiently fills the cross section of the gasket installation groove 2c of the mounting base 2.

The pretreatment of the mounting base 2 is performed by washing the mounting base 2 and then applying an adhesive.
At this time, as the adhesive to be applied to the surface of the mounting base 2 to which the elastic tubular portion 3 is joined, a conventionally known adhesive suitable for vulcanizing adhesion with the unvulcanized rubber for the elastic tubular portion is used. . As the adhesive to be applied to the surface of the mounting base 2 to which the gasket 4 is joined, a conventionally known adhesive suitable for vulcanization adhesion with the unvulcanized rubber for gasket is used. As a coating method of the adhesive, various conventionally known methods such as brush coating, dipping and spraying may be used alone or in combination.

Preparation of each unvulcanized rubber and mounting base 2
When the pretreatment of (1) is completed, the molding process using the molding die M is performed. In this molding process, a string-shaped unvulcanized rubber for gasket cut into a length along the gasket installation groove 2c of the mounting base 2 is set so as to be pressed against the gasket installation groove 2c. Then, since the unvulcanized rubber for gasket has viscoelasticity, as shown in FIG. 5, the state where the unvulcanized rubber for gasket adheres to the gasket installation groove 2c of the mounting base 2 can be maintained. As a result, the first rubber set state is obtained in which the unvulcanized rubber for gasket is attached to the gasket installation groove 2c, which is the site where the gasket 4 of the attachment base 2 is formed.

Next, the mounting base 2 in the first rubber set state shown in FIG. 5 is set in the cavity C of the molding die M shown in FIG. As a result, as shown in FIG. 6, the gasket forming portion Cg of the cavity C of the molding die M, more specifically, the gasket forming portion Cg of the cavity C and the mounting base 2.
The unvulcanized rubber for gaskets is filled into the space surrounded by the gasket installation groove 2c and the elastic tube for the elastic tubular part forming portion Cp of the cavity C from the injection port Ma formed in the molding die M. The unvulcanized rubber for the profile is filled. That is, compression molding is performed on the unvulcanized rubber for the gasket and injection molding is performed on the unvulcanized rubber for the elastic tubular portion at the same time. As a method of filling the elastic tubular portion forming portion Cp of the cavity C with the elastic tubular portion unvulcanized rubber, a pot containing the elastic tubular portion unvulcanized rubber is provided in the molding die M. It can be selected from various conventionally known methods such as injection method and injection method.

Then, as shown in FIG. 7, the cavity C
In the state in which the unvulcanized rubber is filled in the elastic tubular portion forming portion Cp and the gasket forming portion Cg of FIG. Molding of elastic cylindrical portion 3 by vulcanization of vulcanized rubber, gasket 4 by vulcanization of unvulcanized rubber for gasket
And the elastic cylindrical portion 3 and the gasket 4 are bonded to the mounting base 2 at the same time by vulcanization bonding to obtain an integrated molded product, which is released from the molding die M to complete the finished product (Fig. 1 to obtain the manifold 1) shown in FIG.

According to the method of manufacturing the manifold 1 of this embodiment having such a configuration, the elastic tubular portion 3 and the gasket 4 can be easily integrated with the mounting base 2, and the elastic tubular portion can be easily integrated. 3 and the gasket 4 can be easily formed from different materials that are optimal for their respective characteristics.

Further, according to the method for manufacturing the manifold 1 of the present embodiment, since the gasket forming portion Cg of the cavity C of the molding die M is not required to be filled with the unvulcanized rubber for gasket, an injection port is required. The material used for the gasket 4 can be suppressed to the amount required to form the gasket 4.

FIG. 8 shows a second embodiment of the method for manufacturing the manifold 1 of this embodiment. In the method of manufacturing the manifold 1 of the present embodiment, the mounting base 2 that has been subjected to the same pretreatment as that of the manufacturing method of the above-described first embodiment is set in the molding die MA, and is injected from the injection port Ma shown in the upper part of FIG. The elastic tubular portion forming portion Cp of the cavity C of the molding die MA is filled with the unvulcanized rubber for the elastic tubular portion, and the gasket forming portion C of the cavity C is introduced from the inlet Mb shown in the lower part of FIG.
Fill g with unvulcanized rubber for gaskets.

That is, in the method of manufacturing the manifold 1 of the present embodiment, the first rubber set state in which the unvulcanized rubber for gasket is attached to the gasket installation groove 2c of the attachment base 2 in the method of production of the first embodiment described above. And the elastic tubular portion forming portion C of the cavity C from the injection port Ma formed in the molding die MA instead.
At the same time as filling p with the unvulcanized rubber for the elastic tubular portion, the unvulcanized rubber for gasket is filled from the inlet Mb to the gasket forming portion Cg of the cavity C. Therefore, injection molding is performed on both the unvulcanized rubber for the gasket and the unvulcanized rubber for the elastic tubular portion.

Other structures are the same as those of the manufacturing method of the manifold 1 of the first embodiment described above, and therefore detailed description thereof will be omitted.

According to the method of manufacturing the manifold 1 of the present embodiment having such a configuration, the elastic tubular portion 3 and the gasket 4 can be easily attached to the mounting base 2 as in the method of manufacturing the first embodiment described above. The elastic tubular portion 3 and the gasket 4 can be formed of different materials optimal for their respective characteristics. In addition, since the elastic tubular portion forming portion Cp and the gasket forming portion Cg of the cavity C of the molding die MA can be filled with two different kinds of materials at the same time, the productivity can be improved.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified as necessary.

[0038]

As described above, according to the manifold of the present invention according to claim 1, the generation of ozone cracks in the elastic tubular portion can be prevented, and the mounting surface of the mounting base with the engine can be used for a long period of time. This has an extremely excellent effect such that a gasket that keeps stable sealing performance and prevents fluid leakage can be easily integrated.

Further, according to the method for manufacturing a manifold of the present invention according to claim 2, the elastic tubular portion and the gasket can be easily integrated with the mounting base, and the elastic tubular portion and the gasket can be formed. The material has an extremely excellent effect such that it can be formed of a material that is optimal for each characteristic, and that the material used for the gasket can be suppressed to the amount necessary for forming the gasket.

Further, according to the method for manufacturing a manifold of the present invention according to claim 3, the elastic tubular portion and the gasket can be easily integrated with the mounting base, and the elastic tubular portion and the gasket can be formed. It has an extremely excellent effect that it can be formed of a material optimal for each characteristic and that productivity can be improved.

[Brief description of drawings]

FIG. 1 is a front view showing a main part of an embodiment of a manifold according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an enlarged cross-sectional view of the vicinity of the gasket installation groove of the manifold of FIG.

FIG. 4 is a first method of manufacturing a manifold according to the present invention.
Sectional drawing which shows the principal part of the shaping die used for embodiment.

FIG. 5 is a first method of manufacturing a manifold according to the present invention.
Sectional drawing which shows the progress of the manufacturing process of embodiment.

FIG. 6 is a first method of manufacturing a manifold according to the present invention.
Sectional drawing which shows the intermediate process following FIG. 5 of the manufacturing process of embodiment.

FIG. 7 is a first method of manufacturing a manifold according to the present invention.
Sectional drawing which shows the intermediate process following FIG. 6 of the manufacturing process of embodiment.

FIG. 8 is a second manufacturing method of the manifold according to the present invention.
Sectional drawing which shows the progress of the manufacturing process of embodiment.

[Explanation of symbols]

1 manifold 2 Mounting base 2b Mounting surface 2c Gasket installation groove 3 Elastic tubular part 4 gasket 4a protrusion 5 channels M, MA molding die C cavity Cg Gasket forming part Cp elastic tubular part forming part Ma, Mb inlet

Claims (3)

[Claims] 1. A manifold in which a mounting base body connected to an engine and an elastic tubular portion connected to a carburetor are integrated, wherein fluid leakage is prevented from being attached to an engine mounting surface of the mounting base body. The material of the elastic tubular portion is an alloy of nitrile rubber and polyvinyl chloride, and the material of the gasket is selected from the group consisting of hydrogenated nitrile rubber, fluorine rubber and epichlorohydrin rubber. Manifold characterized by being one 2. The method for manufacturing a manifold according to claim 1, wherein after attaching the unvulcanized rubber for a gasket to a gasket forming portion of the mounting base, the mounting base and the gasket are placed in a cavity of a molding die. A method for manufacturing a manifold, comprising: setting an unvulcanized rubber for an elastic tubular portion, and then filling an unvulcanized rubber for the elastic tubular portion in a portion where the elastic tubular portion is formed in the cavity. 3. The method for manufacturing a manifold according to claim 1, wherein the mounting base is set in a cavity of a molding die, and then an elastic tubular portion is formed in an elastic tubular portion forming portion of the cavity of the molding die. A method for manufacturing a manifold, characterized in that the unvulcanized rubber for a part is filled and the unvulcanized rubber for a gasket is filled in a gasket forming portion of a cavity.