JPH065061B2 - Manufacturing method of intake manifold - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an intake manifold used in, for example, an automobile engine.

In this specification, the term "aluminum" includes aluminum alloy as well as pure aluminum. In addition, in this specification, the term "wrought material" refers to an article formed by plastic working such as extrusion, impact extrusion, or forging.

2. Description of the Related Art A conventional intake manifold used for a gasoline engine of an automobile equipped with a carburetor has been manufactured by casting the main pipe and the branch pipe as a whole. However,
In the case of a casting intake manifold, the wall thickness of the peripheral wall cannot be reduced to a certain extent or more due to the flowability of the molten metal during casting, which causes a problem of increased weight.

So, as an intake manifold that solved the above problems,
As an intake manifold for an automobile, there is known one including a plenum chamber made of an aluminum alloy casting and a branch pipe made of an aluminum alloy wrought material (Jitsuko Sho 40-2112).
No. 2). However, in this intake manifold, since a branch pipe made in advance is integrally cast with an aluminum alloy and connected to the plenum chamber, the branch pipe is connected to the intake manifold. It was Moreover, in this intake manifold, fuel particles adhere to the inner surface of the branch pipe and become difficult to flow,
There is a problem that a predetermined amount of fuel cannot be sent to the cylinder of the engine and normal combustion does not occur in the cylinder.

An object of the present invention is to solve the above problems, and to provide a method capable of easily manufacturing an intake manifold capable of improving intake efficiency and smoothing the flow of fuel particles.

Means for Solving the Problems The method for manufacturing an intake manifold according to the present invention comprises a main pipe having one end opened and the other end closed, and a plurality of branch pipes each of which is an extruded pipe connected to the main pipe. A method of manufacturing a branch pipe used in an intake manifold, comprising: forming a plurality of aluminum extruded profile pipe materials having a large number of linear grooves extending in a longitudinal direction on an inner peripheral surface; A twisting process to form a spiral groove over the entire length on the inner peripheral surface, and a step of bending the pipe material to form a plurality of branch pipes having the spiral groove over the entire inner surface. And a process of brazing each branch pipe to the main pipe.

The manifold is applied to an internal combustion engine such as an automobile engine provided with a carburetor, an electronically controlled fuel injection device, and an injector for an automobile in which an injector is arranged in a portion near a main pipe in a branch pipe or in the main pipe. To be done.

In the above, the main pipe is made of an wrought aluminum material, or may be made of a cast aluminum product. In the case of the former, a plurality of holes are formed in the peripheral wall of the main pipe, and a cylindrical outward projecting portion for connecting a branch pipe is integrally formed around each hole. Are preferably connected in a fitted state. The hole and the branch pipe connecting cylindrical outer protruding portion, for example, after forming a hole in the peripheral wall of the main pipe, burring the portion around the hole,
Alternatively, it is preferable that the peripheral wall of the main pipe is subjected to bulging to form a cylindrical bulging portion having a closed tip, and then a hole is formed in the tip closing wall and burring is performed around the hole. Further, it is preferable to form a concave spherical surface on the inner surface of the closing wall of the main pipe. This is because the sound deadening effect can be obtained.

Operation According to the method for manufacturing the intake manifold of the present invention, the branch pipe having a remarkable effect described below is provided with a plurality of aluminum extruded profile pipes having a large number of linear grooves extending in the longitudinal direction on the inner peripheral surface thereof. Since it can be made by twisting the material and bending the pipe material,
The manufacturing work is simplified.

Moreover, since the plurality of branch pipes are connected to the main pipe by brazing, the work is easy.

Furthermore, in the intake manifold manufactured by this method, the spiral groove formed on the inner peripheral surface of the branch pipe causes the air flow in the branch pipe to be a turbulent flow. The flow velocities at are equal and the intake efficiency is improved. Further, as a result of the turbulence of the air flow, the fuel particles injected into the branch pipe easily adhere to the inner peripheral surface of the branch pipe, which flows smoothly along the spiral groove and the cylinder head. The result is always normal combustion in each cylinder.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the entire intake manifold manufactured by the method of the present invention and used in an automobile engine. In FIG. 1, the intake manifold (1) has one end open and the other end closed, and a plurality of holes in the peripheral wall.
(11) is formed and a main pipe (10) made of an aluminum wrought material integrally provided with a cylindrical outer protruding portion (12) for branch pipe connection around each hole (11), and one end Is provided with a plurality of branch pipes (20) made of an aluminum extruded shape member connected to the branch pipe connecting tubular projections (12) in a fitted state.

The closing wall (13) at the other end of the main pipe (10) has a semispherical shape protruding outward, and its inner surface is a concave spherical surface. This can be expected to have a silencing effect. An expanded tube portion (14) is formed at the tip of the cylindrical outward protruding portion (12). A throttle body mounting flange (21) made of cast aluminum is fixed to the open end of the main pipe (10). A throttle body (not shown) having a built-in throttle valve is attached to the throttle body mounting flange (21), and an air supply pipe from an air cleaner is connected to the throttle body.

As shown in FIG. 2, a large number of spiral grooves (26) parallel to each other are formed on the inner peripheral surface of the branch pipe (20) at a predetermined pitch over the entire length. The cross section of the groove 26 is V-shaped as shown in FIG. The cross section of this groove (26) is as shown in FIG. May be The tip ends of the branch pipes (20) are collectively connected to one mounting flange (23) for attachment to the cylinder head, and the branch pipes (2) are connected via the mounting flange (23).
0) is connected to the cylinder head of the engine (not shown). The mounting flange (23) may be made of an aluminum wrought material or an aluminum cast product. The mounting flange (23) has a laterally rectangular shape and is provided with four holes (not shown) and a branch pipe connecting tubular projection (24) integrally provided around the holes. A tube expansion portion (25) is provided at the tip of the protrusion (24). And branch pipe
(20) is inserted in the diffusion part (25) at the tip of the protrusion (24),
It is brazed. Although not shown, the branch pipe (2
Fuel is injected into a position near the main pipe (10) of (0).

In such a configuration, the spiral groove (26) causes the air flow in the branch pipe (20) to be turbulent, and the flow velocities near the axis of the branch pipe (20) and the pipe wall are equalized, so that the intake effect is improved. Is improved. Further, as a result of the air flow becoming turbulent, the fuel particles injected into the branch pipe (20) easily adhere to the inner peripheral surface of the branch pipe (20), which is a spiral groove ( Flow smoothly along 26) toward the cylinder head.

The method for manufacturing the intake manifold (1) is as follows.

First, make the main pipe (10) as follows. That is, after pressing the closing wall of the aluminum impact extrusion pipe having one end opened and the other end closed to form an outwardly projecting hemispherical closing wall (13), the impact extrusion pipe peripheral wall The portion to which the branch pipe (20) is connected is subjected to bulging to form a cylindrical bulging portion with a closed end. Then,
A hole is formed in the central portion of the cylindrical bulging portion excluding the peripheral edge portion of the closing wall. Further, by burring, the remaining portion around the hole in the tip closing wall is outwardly bent so as to be flush with the peripheral wall of the tubular bulging portion, and the bulging portion is provided with the tubular outward projecting portion for branch pipe connection ( 12) and holes (11) are formed in the peripheral wall. Finally, expand the tip of the outward protrusion (12) to
4) is formed. In this way, the main pipe (10) is made.

The main pipe (10) may also be made by the following method. That is, first, in the same manner as above, after making the closing wall of the pipe a hemispherical closing wall (13), a hole smaller than the hole (11) is formed in the portion of the peripheral wall of the pipe to which the branch pipe (20) should be connected. Open Next, a burring process is applied to the peripheral portion of the hole to bend the portion outwardly to form a branch pipe connecting cylindrical outward protruding portion (12) and a hole (11). Then, the expanded portion (14) is formed in the same manner as above. However, the method of forming the main pipe (10) is not limited to the above.

Further, the branch pipe (20) is made as follows. That is, first, a plurality of extruded profile pipe materials having a large number of linear grooves extending in the longitudinal direction are formed on the inner peripheral surface. Then, each pile material is twisted to form a spiral groove over its entire length on its inner peripheral surface. Then, the pipe material having the spiral groove formed on the inner peripheral surface is bent into a substantially U shape. In this way, a plurality of branch pipes (20) are created.

Separately from this, a throttle body mounting flange (21) and a mounting flange (23) are prepared.

After that, one end of each branch pipe (20) is fitted into the expanded pipe portion (14) at the tip of the tubular outer protruding portion (12) of the main pipe (10), and the other end is attached to the mounting flange (23). Tube expansion part at the end of the cylindrical protrusion (24)
(25) Fit in. Then, connect each branch pipe (20) to both expansion parts.
Braze to (14) (25). Further, the throttle body mounting flange (21) is fixed to the open end of the main pipe (10) by brazing, for example. In this way, the intake manifold is manufactured.

In the above embodiment, the main pipe (10) is made of an wrought aluminum material, but the present invention is not limited to this, and the main pipe (10) has a hole (11) and a branch pipe connecting tubular outer side. Protrusion
It may be made of an aluminum cast product including the flange (21) and the throttle body mounting flange (21).

EFFECTS OF THE INVENTION According to the method for manufacturing the branch pipe for the intake manifold of the present invention, as described above, the manufacturing work of the branch pipe having a remarkable effect and the connecting work to the main pipe of the branch pipe are simplified, The entire intake manifold can be easily manufactured.

Moreover, in the intake manifold manufactured by the method of the present invention, the spiral groove formed on the inner peripheral surface of the branch pipe causes the air flow in the branch pipe to be a turbulent flow, and the vicinity of the axis of the branch pipe and the vicinity of the pipe wall The flow velocities at and become equal and the intake efficiency is improved. Further, as a result of the turbulence of the air flow, the fuel particles injected into the branch pipe easily adhere to the inner peripheral surface of the branch pipe, which flows smoothly along the spiral groove and the cylinder head. The result is always normal combustion in each cylinder.

[Brief description of drawings]

1 is a perspective view showing an intake manifold manufactured by the method of the present invention, FIG. 2 is an enlarged vertical sectional view showing a part of a branch pipe, and FIG. 3 is a line III-III of FIG. Arrow view, 4th
The figure is a view corresponding to FIG. 3 showing a modification of the cross-sectional shape of the spiral groove. (1) ... intake manifold, (10) ... main pipe, (20) ... branch pipe, (2
6)… spiral groove.

Continuation of the front page (56) References JP-A-58-148260 (JP, A) JP-A-53-25179 (JP, A) JP-B-40-21122 (JP, Y1)

Claims (1)

[Claims] 1. A method for manufacturing an intake manifold, comprising: a main pipe having one end open and the other end closed; and a plurality of branch pipes each having an extruded pipe connected to the main pipe. Forming multiple extruded aluminum pipe materials with a number of linear grooves extending in the length direction on the surface, and twisting the pipe material to form a spiral groove over the entire inner surface And a step of bending the pipe material to form a plurality of branch pipes each having a spiral groove formed over the entire inner peripheral surface, and brazing each branch pipe to the main pipe. And a method of manufacturing an intake manifold.