JPH09217661A - Intake manifold and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intake manifold furnished with a fuel rail advantageous for further improvement of fuel resistance permeability and further improvement of an assembling property. SOLUTION: An intake manifold 2 is furnished with an intake manifold main body 3 and a fuel rail 4 integrally provided with it. The intake manifold main body 3 has a plural number of branch pipes 31 having intake ports 30 and an arm part 32. The fuel rail 4 is constituted of a cylindrical pipe material 40 formed of a metallic pipe body and a metal cast made cast and inserted part 42 to bury and hold the pipe material 40 by casting and inserting an outer wall surface of the pipe maternal 40. The metallic pipe body constituting the pipe material 40 is formed by rolling, and accordingly, it has favourable fuel permeation resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake manifold integrally provided with a fuel rail for holding a fuel injector for injecting fuel and a method for manufacturing the intake manifold.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIG. The intake manifold 100 plays a role of guiding air to an intake port 201 of a cylinder of the internal combustion engine 200, and includes a plurality of branch pipes 102 having intake holes 101 communicating with the intake port 201 of the internal combustion engine 200. There is.

Further, a fuel rail 300 is used in a fuel injection type internal combustion engine 200. The fuel rail 300 mounts the fuel injectors 400 for injecting fuel along the direction in which the cylinders of the internal combustion engine 200 are arranged in parallel, and thus has the shape of a crossbar extending in the direction in which the cylinders of the internal combustion engine 200 are arranged in parallel. . The fuel rail 300 is formed of an aluminum extruded material, and has a long hole-shaped central hole 301 formed by drilling and a side hole 302 into which the fuel injector 400 is fitted and attached. A fuel passage for sending fuel to the fuel injector 400 is formed by the central hole 301 and the side hole 302.

Conventionally, the intake manifold 100 is used.
A threaded hole 106 is formed on an end surface of a mounting boss 104 formed on the branch pipe 102 of FIG. The bolt 109 is inserted into the insertion hole 100f, and the male screw portion of the bolt 109 is screwed into the screw hole 106 of the mounting boss 104, whereby a separate fuel rail 3 is provided.
00 is attached to the intake manifold 100.

[0005]

In the above-mentioned prior art, it is desired to improve the assemblability of the fuel rail 300 and the intake manifold 100. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an intake manifold including a fuel rail that is advantageous for improving the assemblability.

[0006]

An intake manifold according to a first aspect of the present invention is an intake manifold main body having a plurality of branched intake holes communicating with an intake port of a cylinder of an internal combustion engine, and a direction in which the cylinders of the internal combustion engine are arranged in parallel. Is formed integrally with the intake manifold main body along with, and is configured with a fuel rail that forms a fuel passage for sending fuel to the fuel injector while mounting the fuel injector. A pipe having a central hole extending along the center hole and a plurality of side holes opened in a direction intersecting with the axis of the central hole and into which a fuel injector is fitted, and forming a fuel passage with the central hole and the side holes. Material and a cast-in portion that is integrally molded with the intake manifold body and casts and holds the pipe material. It is characterized in that there.

The side hole opens in a direction intersecting with the axis of the central hole. Opening in a direction intersecting with the central axis of the central hole means that the axial center of the side hole intersects with the axial center of the central hole when viewed from one side. Including. According to the intake manifold of the second aspect, in the first aspect, the pipe material is formed of metal or hard resin, and the intake manifold body and the cast-in portion are made of resin as a base material.

According to the intake manifold of claim 3, in the intake manifold body according to claim 1, the intake manifold main body has an arm portion, and the arm portion and the cast-in portion of the fuel rail are integrally connected. It is what According to the intake manifold of the fourth aspect, in the first aspect, the pipe material is provided with a plurality of side cylinders that project in a direction intersecting the axis of the pipe material and form side holes. The seal point that seals between the outer wall surface of and the inner wall surface of each side cylinder is
It is characterized in that it is located closer to the central hole than the boundary region between the tip of the side cylinder and the cast-in portion.

A method of manufacturing an intake manifold according to a fifth aspect of the present invention is a pipe member having a central hole extending in the axial direction and a plurality of side holes opening in a direction intersecting with the axial center of the central hole, and an intake. A step of setting a pipe material in the sub-molding cavity of the molding dies using a molding die having a molding cavity having a main molding cavity for molding the manifold body and a sub-molding cavity for molding the fuel rail; Injecting the molding material into the molding cavity of the molding die, casting the pipe material with the molding material to form the casting envelope, and integrally molding the fuel rail and the intake manifold body to obtain the intake manifold. It is what

[0010]

According to the first aspect of the present invention, the cast-in portion of the fuel rail and the intake manifold body are integrally formed. In the fuel rail, the fuel passage through which the fuel passes is made of a pipe material, and therefore has good fuel permeation resistance. The central hole of the pipe material is generally a straight shape, but may be bent if necessary.

As the pipe material, it is preferable that the pipe material can be made of metal or hard resin and has good fuel oil resistance. Light metals such as aluminum alloys can be used as the metal. Aluminum alloys include Si, Mg, Cu, Fe
Those reinforced by including at least one kind of alloying element such as Further, as a metal constituting the pipe material, an iron-based material such as stainless steel, alloy steel or carbon steel can be adopted.

The resin can be appropriately selected regardless of whether it is a thermosetting resin or a thermoplastic resin, and a polyamide type, an epoxy type or the like can be adopted, and it is also preferable to polymerize it as necessary. A reinforcing material may be added to the resin. As the reinforcing material, those having a short fiber shape, a long fiber shape, a particle shape or the like can be adopted. As the reinforcing material, glass fiber, carbon fiber, aramid fiber or the like can be adopted.

The fuel rail pipe material has a central hole and a side hole opened in a direction intersecting with the axis of the central hole. A fuel passage is formed by the central hole and the side hole. A fuel injector is fitted and held in the side hole. According to the third aspect, the intake manifold main body integrally includes the arm portion, and the arm portion and the cast-in portion of the fuel rail are integrally connected. In this case, the degree of freedom of the position of the fuel rail is secured by appropriately setting the length, shape, orientation, etc. of the arm portion. The number of arms can be appropriately selected, and may be one or plural.

According to the fourth aspect, the pipe material is provided with a plurality of side cylinders forming side holes. The length of the side cylinder can be appropriately selected. A seal point is provided to seal between the outer wall surface of the fuel injector and the inner wall surface of the side cylinder. The seal point is for sealing fuel leaks. The seal point can be generally secured by a seal material such as a rubber material. Since this seal point is located closer to the central hole than the boundary area between the tip of the side cylinder and the cast-in shell, the fuel is prevented from reaching the boundary area.

According to the method of claim 5, the molding material is injected into the molding cavity of the molding die, the pipe material is cast in the molding material, and the fuel rail and the intake manifold body are integrally molded to form the intake manifold. To get Since the contracting force acts when the molding material is solidified, the integral bonding property between the pipe material and the casting insert material is secured. If at least one of the concave portion and the convex portion is formed on the outer wall surface of the pipe material, the integral bondability is further improved. For example, it is also preferable to roughen the surface or form a locking groove or a locking projection.

A metal or resin can be used as the molding material. Light metal such as aluminum alloy can be adopted as metal,
Further, iron-based materials such as gray cast iron and spheroidal graphite cast iron can be adopted.
The resin can be selected regardless of whether it is a thermosetting resin or a thermoplastic resin, and for example, known resins such as polyamide, epoxy, polyester, phenol and hydrocarbon can be used. A fibrous or particulate reinforcing material may be added to the resin. The molding means is not particularly limited, and when the molding material is metal, casting such as die casting or sand mold casting, and when it is resin, injection molding or the like can be adopted.

[0017]

Embodiments of the present invention will be described below. FIG. 1 shows a main part of a cylinder of the internal combustion engine 1. The internal combustion engine 1 includes a cylinder block 10, a cylinder head 11 attached to the cylinder block 10, a piston 13 fitted in a cylinder bore 12 of the cylinder block 10, a combustion chamber 14,
An intake port 15 communicating with the combustion chamber 14, an intake valve 16 that opens and closes the intake port 15, an exhaust port 17 that discharges combustion gas, and an exhaust valve 1 that opens and closes the exhaust port 1.
8 is provided. The cylinder block 10 and the cylinder head 11 can be made of aluminum casting or iron casting.

FIG. 1 shows a state in which an intake manifold 2 is attached to an internal combustion engine 1. Intake manifold 2
Includes an intake manifold main body 3 and a fuel rail 4 provided integrally with the intake manifold main body 3. The intake manifold body 3 is
Curved intake hole 3 communicating with intake port 15 of internal combustion engine 1
It has a plurality of branch pipes 31 each having 0, an arm portion 32 that is integrally connected from an intermediate portion of the branch pipe 31, and a surge tank 33 that is integrally connected to one end portion of the branch pipe 31. According to this embodiment, as can be understood from FIG. 1, the arm portion 32 projects in a direction intersecting the tangential direction Hc of the branch pipe 31. The intake manifold body 3 is made of cast metal and can be formed of an aluminum alloy (for example, JIS AC2B).

The fuel rail 4 is formed integrally with the arm portion 32 of the intake manifold body 3. The fuel rail 4 is provided in each combustion chamber 14 of each cylinder of the internal combustion engine 1.
Fuel injectors 5 for injecting fuel are mounted in parallel with each other, and extend in a crossbar shape along the parallel direction of the cylinders of the internal combustion engine 1. The fuel injected by the fuel injector 5 may be gasoline or light oil, but may be alcohol.

The fuel rail 4 is composed of a cylindrical pipe material 40 formed of a metal pipe body, and a cast-in metal casting part 42 for casting and encapsulating the outer wall surface of the pipe material 40 to embed and hold the pipe material 40. Has been done. The cast-in portion 42 is made of the same material as that of the intake manifold body 3 because it is a casting integrally formed with the intake manifold body 3. Since the metal tube body that constitutes the pipe member 40 is formed by rolling, there is no possibility of presence of cavities and the like, and good fuel permeation resistance is obtained.

FIG. 2 is an enlarged view of the main part of FIG. As shown in FIG. 2, the pipe member 40 has a central hole 44 having a circular cross section and a long shaft hole having a shaft core P1 and a central hole 4.
4, a plurality of cylindrical side cylinders 46 having an axis P2 intersecting with the axis P1 of 4 and a plurality of side holes 48 formed by the inner wall surface of the side cylinder 46. The central hole 44 and the side hole 48 form a fuel passage K through which the fuel fed to the fuel injector 5 passes. The pipe member 40 can be formed of an aluminum pipe body, but may be a steel pipe body such as stainless steel. The material of the aluminum tube body may be JIS-6063, for example.

As shown in FIG. 2, a cylindrical mounting portion 5p of the fuel injector 5 is fitted and held in the side hole 48. A ring-shaped sealing material 49 is interposed between the outer wall surface of the mounting portion 5p and the inner wall surface of the side hole 48 to ensure the sealing performance against fuel. Therefore, sealing material 4
9 forms a seal point Ma. The sealing material 49 is preferably formed of a material having good fuel resistance, and may be formed of, for example, fluororubber.

By the way, it is not preferable that the fuel enters the boundary between the pipe material 40 and the cast-in portion 42. The approach start position is the tip 46w of the side cylinder 46. In this respect, according to the present embodiment, as can be understood from FIG. 2, the tip end 46w of the side cylinder 46 is closer to the fuel injector 5 side than the sealing point Ma formed by the sealing material 49. That is,
The seal point Ma is closer to the central hole 4 than the boundary region Mc between the tip 46w of the side cylinder 46 of the pipe material 40 and the cast-in casing 42.
Located on the 4 side.

Therefore, the fuel is sealed at the sealing point Ma by the sealing material 49, and further entry, that is, entry to the tip 46w side is suppressed. Therefore, it is advantageous to prevent the fuel from reaching the boundary region Mc. Therefore, entry of fuel into the boundary between the pipe material 40 and the cast-in portion 42 is suppressed. Therefore, even when there is a difference in thermal expansion or a difference in thermal contraction between the pipe material 40 and the cast-in portion 42, it is effective in preventing the ingress of fuel.

Next, a method of manufacturing the intake manifold 2 according to this embodiment will be described. First, a seamless long pipe material 40 in which the central hole 44 shown in FIG. 3 is formed by at least one of rolling, drawing, and extruding is used. Then, a plurality of side cylinders 46 are arranged side by side on the peripheral wall of the pipe member 40 at predetermined intervals. As described above, the axis P2 of the side cylinder 46
Is in a direction intersecting with the axis P1 of the pipe member 40, that is, substantially orthogonal. The number of side cylinders 46 is the same as the number of cylinders of the internal combustion engine 1, that is, the number of fuel injectors 5.
In the same manner as described above, such a pipe material 40 has a long hole-shaped central hole 44 extending in the direction of the axis P1 and a side hole 48 opened in a direction intersecting with the axis P1 of the central hole 44.

Further, as shown in FIG. 5, using the molding die 8, the pipe material 40 is set in a predetermined portion of the sub-molding cavity 82 for molding the fuel rail 4 in the molding cavity 80 of the molding die 8. A mold, a sand mold, or the like can be used as the molding die 8. The tip of the pipe material 40 is closed by a sealing material 49. The sealing material 49 is welded or screwed into the pipe material 4
Can be fixed at 0.

Further, in this embodiment, as shown in FIG. 6, among the molding cavities 80 of the molding die 8, the main molding cavity 84 for molding the intake manifold body 3 is
The core 86 is held. As the core 86, a collapsible core such as a shell core or a water-soluble core, and in some cases, a movable core can be adopted. The core 86 is for forming the intake hole 30 described above. In addition, it is also preferable to preheat the pipe material 40 if necessary.

Next, the molding cavity 80 of the molding die 8 is filled with a high temperature molten metal as a molding material to solidify the molten metal in the molding cavity 80. This makes the pipe material 4
0 is cast-in, and the cast-in portion 42 described above is formed as a casting. Similarly, the intake manifold body 3 is also formed as a casting. According to this embodiment, the intake manifold body 3 and the cast-in envelope 42 are integrally formed.

The contraction force when the molten metal solidifies and the contraction force accompanying the cooling after solidification acts in the direction in which the pipe material 40 is tightened, so that the integral connection between the pipe material 40 and the cast-in portion 42 is achieved. Secured. In particular, since the pipe member 40 has a circular cross section, the contracting force is easily equalized in the circumferential direction.
This is advantageous for ensuring uniform bonding. By the way, pipe material 40
When forming the side tube 46 on the
As shown in FIG.
Is formed in advance, the pipe material 40 is set in the bulge processing die 9, and the hydraulic pressure such as hydraulic pressure or water pressure is indicated by the arrow A in that state.
It is also possible to form the side cylinder 46 by acting in one direction to bend the peripheral wall and press it against the mold surface 91 of the bulging mold 9.

Further, as shown in FIGS. 8 (A) and 8 (B), holes 40k are formed in the peripheral wall of the pipe material 40 in advance, and separate side cylinders 46 are integrally connected by welding portions 46n. You can also In some cases, the pipe member 40 integrally provided with the side cylinder 46 may be formed by casting or resin molding. As described above, according to this embodiment, the fuel rail 4
Since the fuel passage K through which the fuel passes is composed of the pipe material 40, it has a good fuel permeation resistance. The pipe material 40 according to this embodiment has good fuel permeation resistance because it is formed by rolling, drawing, extrusion, or the like.

Further, according to this embodiment, the fuel rail 4 and the intake manifold body 3 are integrally formed, so that the assembling property is improved. Also, unlike the prior art shown in FIG. 10, the step of fastening the bolt 109 to attach the separate fuel rail 300 to the intake manifold 100 can be eliminated, so when fastening the bolt 109 with a tool, the fastening work and the tool It is possible to prevent the branch pipe 102 from interfering with the insertion.

Further, according to this embodiment, the pipe material 40 also functions as a core body of the cast-in portion 42. Therefore, the cast-in portion 4
The effect of reinforcing 2 with the pipe material 40 can also be expected. Further, according to this embodiment, the intake manifold body 3 is provided with the arm portion 32, and the arm portion 32 and the fuel rail 4 are provided.
Since it is integrally connected to the cast-in casing 42, the degree of freedom in the position for holding the fuel rail 4 can be increased by appropriately selecting the length, shape, and orientation of the arm 32.

In addition, according to the present embodiment, the contracting force when the molten metal solidifies acts on the pipe material 40 in the tightening direction, so that the integrity of the pipe material 40 and the cast-in portion 42 can be improved. (Other Example) FIG. 9 shows another example. This example has basically the same configuration as that of the above-described embodiment, and the components having basically the same functions are denoted by the same reference numerals. Also in this example, the same effect as that of the above-described embodiment can be obtained, and the fuel permeation resistance can be improved by the pipe member 40.

According to this example, the cast-in portion 42 for casting and enclosing the pipe material 40 is made of a polyamide resin containing glass fiber as a reinforcing material. The intake manifold body 3 (not shown in FIG. 9) is also integrally molded with the cast-in casing 42, and thus is similarly formed of a polyamide resin containing glass fibers. In this embodiment, the intake manifold body 3 and the cast-in casing 42 are formed of resin as a base material, which is advantageous for weight reduction. Further, since the metal hard pipe material 40 is embedded in the resin cast-in portion 42, the resin cast-in portion 42 is connected to the pipe material 40.
You can also expect the effect of reinforcement. Further, even if the cast-in portion 42 is made of resin as a base material, it is also advantageous to enhance the fuel permeation resistance by the metal pipe material 40.

[0035]

According to the first aspect of the present invention, in the fuel rail, the fuel passage through which the fuel passes is made of a pipe material, and therefore has a good fuel permeation resistance. Further, since the fuel rail and the intake manifold body are integrally formed, the assemblability is improved.

According to the second aspect, the intake manifold main body and the cast-in casing are made of resin as a base material, and the pipe material embedded in the cast-in casing is made of metal or hard resin. The effect of reinforcing with pipe material can also be expected. According to claim 3, since the intake manifold main body is provided with the arm portion and the arm portion and the cast-in portion of the fuel rail are integrally connected, the length, shape and direction of the arm portion can be appropriately selected. , The degree of freedom of the position of the fuel rail can be increased.

According to the fourth aspect, since the seal point is located closer to the central hole than the boundary region between the tip of the side pipe of the pipe material and the cast-in portion, the fuel in the fuel passage is in the boundary region. Reaching is suppressed. According to the method of claim 5, it is possible to provide an intake manifold having the above-mentioned effects. In particular, since the contracting force when the molding material solidifies acts in the direction of tightening the pipe material, the integrity of the pipe material and the cast-in insert can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a state in which an intake manifold having a fuel rail is attached to an internal combustion engine.

FIG. 2 is a cross-sectional view showing a main part of a fuel rail.

FIG. 3 is a configuration diagram of a pipe member before a side cylinder is attached.

FIG. 4 is a configuration diagram of the pipe member after the side cylinder is attached.

FIG. 5 is a configuration diagram showing a state in which a pipe material to which a side tube is attached is set in a molding cavity of a molding die.

FIG. 6 is a configuration diagram showing a state in which a core is set in a molding cavity of a molding die.

FIG. 7 is a configuration diagram showing a step of forming a side cylinder.

FIG. 8 is a configuration diagram showing a process of forming a side cylinder.

FIG. 9 is a cross-sectional view showing the main parts of a fuel rail according to another embodiment.

FIG. 10 is a configuration diagram showing a state in which separate fuel rails and intake manifolds are individually attached to an internal combustion engine according to a conventional technique.

[Explanation of symbols]

In the figure, 1 is an internal combustion engine, 3 is an intake manifold body, 30 is an intake hole, 4 is a fuel rail, 40 is a pipe material, 44 is a central hole, 48 is a side hole, 42 is a cast-in portion, and 5
Is a fuel injector, 8 is a mold,

Claims (5)

[Claims] 1. An intake manifold main body having a plurality of branched intake holes communicating with an intake port of a cylinder of an internal combustion engine; and an intake manifold main body extending along the direction in which the cylinders of the internal combustion engine are arranged in parallel. A fuel rail for mounting a fuel injector and forming a fuel passage for sending fuel to the fuel injector, the fuel rail comprising a central hole extending along a direction in which cylinders of an internal combustion engine are arranged, and a central hole A pipe member having a plurality of side holes that are opened in a direction intersecting the axis of the hole and into which a fuel injector is fitted, and that forms a fuel passage with the central hole and the side holes; and the intake manifold body. An intake manifold that is integrally molded with the pipe material and has a cast-in portion that holds the pipe material by casting. Field. 2. The intake manifold according to claim 1, wherein the pipe material is formed of metal or hard resin, and the intake manifold main body and the cast-in envelope are made of resin as a base material. 3. The intake manifold according to claim 1, wherein the intake manifold main body has an arm portion, and the arm portion and the cast-in portion of the fuel rail are integrally connected. 4. The pipe member according to claim 1, wherein the pipe member is provided with a plurality of side cylinders that project in a direction intersecting with the axis of the pipe member and form side holes, and the outer wall surface of the fuel injector and each of the side cylinders. An intake manifold, wherein a seal point for sealing between the inner wall surface of the side cylinder and the center hole side is located more than a boundary region between the tip of the side cylinder and the cast-in insert. 5. A pipe material having a central hole extending in the axial direction and a plurality of side holes opening in a direction intersecting with the axial center of the central hole, and a main molding cavity for molding an intake manifold main body. Using a forming die having a forming cavity provided with a sub-forming cavity for forming a fuel rail, a step of setting the pipe material in the sub-forming cavity of the forming cavities of the forming die, and a forming cavity of the forming die Injecting a molding material into the mold, casting the pipe material with the molding material to form a cast-in portion, and integrally molding the fuel rail and the intake manifold body to obtain an intake manifold. Manufacturing method of intake manifold.