JPH0596461U - Intake manifold for internal combustion engine - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an intake manifold for an internal combustion engine that reduces ventilation resistance in a bent portion of each branch pipe and reduces ventilation resistance near an engine head mounting flange. [Structure] A main pipe 1, a plurality of branch pipes 10 having a bent portion, one end 11 of which is connected to the main pipe 1, and an engine head mounting flange 20 which is connected to the other end 12 of each branch pipe 10.
In the intake manifold for an internal combustion engine, the bent portion 13 of each branch pipe 10 is
The cross-sectional area S1 of the outer region with respect to the center line C is larger than the cross-sectional area S2 of the inner region. Further, the flow path 22 of the mounting portion 21 of the engine head mounting flange 20 connected to the other end 12 of each of the branch pipes 10 and the flow path 23 of the engine head mounting flange 20 which is continuous with the flow path 23 of the engine head mounting flange 20 are The inner cross-sectional shape is substantially the same as the port shape.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an intake manifold for an internal combustion engine having a plurality of branch pipes.

[0002]

[Prior Art]

 Conventionally, as this type of intake manifold for an internal combustion engine, for example, one disclosed in Japanese Patent Laid-Open No. 2-229668 is known.

This will be described with reference to FIG. The intake manifold 50 for an internal combustion engine includes a main pipe 60, a plurality of branch pipes 70 having a bent portion whose one end 71 is connected to the main pipe 60, and an engine head mounting flange 80 which is connected to the other end 72 of each branch pipe 70. Have.

The main pipe 60 is a tubular body having four holes 61 on its side, a flange 62 attached to a throttle body (not shown) on one end, and the other end closed. As shown in FIG. 9, the plurality of branch pipes 70 are formed by bending a round pipe into a substantially U shape. One end 71 of each branch pipe 70 is fitted into the hole 61 of the main pipe 60 and fixed by brazing or welding.

The engine head mounting flange 80 has a cylindrical mounting portion 81 connected to the other end 72 of each branch pipe 70. The flow path 82 of the mounting portion 81 communicates with the hole 83 of the engine head mounting flange 80, as shown in FIG.

An upstream side of the flow path 82 of the mounting portion 81 has a round shape similar to the branch pipe 70. As it goes toward the hole 83 of the engine head mounting flange 80, as shown in FIG. Has changed to.

In the conventional intake manifold 50 for an internal combustion engine thus configured, as shown in FIG. 7, when air is sucked from the throttle body (not shown) side, the air flows from the main pipe 60 to this. It passes through each branch pipe 70 to be connected and flows into a port (not shown) of the engine head through a mounting portion 81 connected to each branch pipe 70 and a hole 83 of an engine head mounting flange 80.

[0008]

[Problems to be solved by the device]

 However, in the above-described conventional intake manifold 50 for an internal combustion engine, since each branch pipe 70 is formed by bending a round pipe into a substantially U shape, the air flowing from the main pipe 60 into each branch pipe 70 is As shown in FIG. 8, in the bent portion 73 of each branch pipe 70, a drift phenomenon occurs in which it flows in the outer region and does not flow in the inner region, thereby increasing the ventilation resistance.

Therefore, the suction efficiency is lowered, which is a factor of deteriorating the engine output performance. Further, since the cross-sectional shape changes rapidly from the round shape to the elliptical shape from the upstream side of the mounting portion 81 of the engine head mounting flange 80 toward the hole 83 of the engine head mounting flange 80, the ventilation resistance is increased. Was there.

As a result, the intake efficiency is lowered, which is a factor of deteriorating the engine output performance. Furthermore, since the cross-sectional shape changes rapidly from the round shape to the elliptical shape from the upstream side of the mounting portion 81 of the engine head mounting flange 80 toward the hole 83 of the engine head mounting flange 80, it has a special shape during manufacturing by casting. I needed a sand core.

The present invention has been made to solve such a problem, and a first object thereof is to make it possible to reduce ventilation resistance in a bent portion of each branch pipe, and a second object thereof is to An object of the present invention is to provide an intake manifold for an internal combustion engine capable of reducing the ventilation resistance in the bent portion of each branch pipe and the ventilation resistance in the vicinity of the engine head mounting flange.

[0012]

[Means for Solving the Problems]

 According to a first aspect of the present invention, there is provided an intake manifold for an internal combustion engine, comprising: a main pipe; a plurality of branch pipes each having one end connected to the main pipe; and a plurality of branch pipes connected to the other end of each branch pipe. The bent portion of each branch pipe is such that the cross-sectional area of the outer region is wider than the cross-sectional area of the inner region of the center line of each branch pipe.

According to a second aspect of the present invention, an intake manifold for an internal combustion engine having a main pipe, a plurality of branch pipes each having one end connected to the main pipe and having a bent portion, and an engine head mounting flange connected to the other end of each branch pipe. In each of the branch pipes, the cross-sectional area of the outer region is wider than the center line of each branch pipe and is larger than the cross-sectional area of the inner region of the branch pipe. The flow path of the mounting portion and the flow path of the engine head mounting flange that is continuous with the flow path have an inner cross-sectional shape that is substantially the same as the port shape of the engine head.

[0014]

[Action]

 In claim 1, when the air introduced from the throttle body side passes through the respective branch pipes connected to the main pipe and reaches the bent portion, the air flow is biased to the outer region, but the outer region is disconnected. Since the area is wider than the cross-sectional area of the inner region, the distribution of streamlines is uniform and the contraction resistance is reduced.

In claim 2, when the air introduced from the throttle body side passes through the respective branch pipes connected to the main pipe and reaches the bent portion, the air flow is lopsided in the outer region, Since the cross-sectional area of the region is wider than the cross-sectional area of the inner region, the distribution of streamlines becomes uniform and the contraction resistance can be reduced.

Since there is little change in the cross-sectional shape from each branch pipe to the engine head mounting flange, the air flow becomes smooth and the ventilation resistance can be reduced.

[0017]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 show an embodiment of an intake manifold for an internal combustion engine according to claim 2.

The intake manifold 30 for an internal combustion engine according to this embodiment includes a main pipe 1, a plurality of substantially U-shaped branch pipes 10 having one end 11 connected to the main pipe 1, and the other end of each branch pipe 10. And an engine head mounting flange 20 that is connected to the shaft 12.

The main pipe 1 is a tubular body having four holes 2 on its side, as in FIG. 7, and has a flange (not shown) attached to a throttle body (not shown) at one end. The other end is closed.

Further, each branch pipe 10 is a tubular body bent into a substantially U shape, and as shown in FIG. 3, the cross-sectional area S3 of the outer region from the center line C of each branch pipe 10 is the cross section of the inner region. It has a generally rice-ball shape that is wider than the area S4.

Therefore, in each of the branch pipes 10 as well, in the bent portion 13, as shown in FIG. 2, the cross-sectional area S1 of the outer region from the center line C of each branch pipe 10 is wider than the cross-sectional area S2 of the inner region. It has a roughly rice ball shape.

2 and 3, the cross-sectional area S1 of the outer region is equal to the cross-sectional area S3 of the outer region, and the cross-sectional area S2 of the inner region is equal to the cross-sectional area S4 of the inner region. 2 and 5, the inside and the outside represent the inside and the outside of the bent portion 13 of each branch pipe 10.

The engine head mounting flange 20 is provided with a tubular mounting portion 21 that connects the other end 12 of each branch pipe 10. The engine head mounting flange 20 is provided with a flow passage 23 that communicates with the flow passage 22 of the mounting portion 21. The flow path 22 of the mounting portion 21 and the flow path 23 continuous with the flow path 22 have a substantially rice ball shape having an inner cross-sectional shape substantially the same as the port shape of the engine head.

In the intake manifold 30 for an internal combustion engine according to the present embodiment thus configured, when air is sucked into the main pipe 1 from the throttle body (not shown) side, the air is as shown in FIG. , Through each branch pipe 10 connected to the main pipe 1, and through the flow passage 22 of the attachment portion 21 connected to each branch pipe 10 and the hole 23 of the engine head attachment flange 20 (not shown). No)).

When the air introduced from the throttle body side passes from the main pipe 1 into each branch pipe 10 connected to the main pipe 1 and reaches the bent portion 13, the air flow is eccentric to the outer region. As shown in FIG. 2, since the cross-sectional area S1 of the outer region is wider than the cross-sectional area S2 of the inner region, the distribution of streamlines becomes uniform and the contraction resistance is reduced as shown in FIGS. be able to.

Furthermore, at the other end 12 of each branch pipe 10, the change in cross-sectional shape is much smaller than that of the conventional intake manifold 50 for an internal combustion engine shown in FIG. Therefore, the ventilation resistance can be reduced.

As described above, according to the present embodiment, since the contraction resistance is reduced, the ventilation resistance in each branch pipe 10 is reduced, the suction efficiency is improved, and the engine output performance is improved. Further, since there is little change in the cross-sectional shape between each branch pipe 10 and the engine head mounting flange 20 and the air flow is smooth, the suction efficiency is improved and the engine output performance is improved.

Further, since the change in the inner surface shape of the engine head mounting flange 20 is small, the inner surface is molded by the slide core built in the mold without using the sand mold core when manufacturing the flange (during casting). Yes, the manufacturing cost is reduced.

In the above embodiment, the cross-sectional area S3 of the outer region is made wider than the cross-sectional area S4 of the inner region over the entire length of each branch pipe 10, but the bent portion 13 is used. However, the cross-sectional area S1 of the outer region may be wider than the cross-sectional area S2 of the inner region.

The above has described the particularly preferred embodiment, but the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the claims.

[0031]

[Effect of the device]

 According to the first aspect, when the intake air flows in each branch pipe, even if the air flow unevenly flows outward at the bend, the bend has a larger cross-sectional area in the outer region than that in the inner region. Since the shape is uniform, the distribution of streamlines is uniform and the contraction resistance is reduced. As a result, intake efficiency is improved and engine output performance is improved.

According to the second aspect, in addition to the effect of the first aspect, since the change in the inner surface shape of the engine head mounting flange is small, the air flow becomes smooth, the intake efficiency is improved, and the engine efficiency is improved. Output performance is improved.

Further, since the change in the inner surface shape of the engine head mounting flange is small, the manufacturing is easier than the conventional product.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an intake manifold for an internal combustion engine according to claim 2.

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

FIG. 3 is a view taken in the direction of arrow X in FIG.

FIG. 4 is a view on arrow Y of FIG.

5 is a cross-sectional view showing an intake air flow in the branch pipe of FIG.

FIG. 6 is an explanatory diagram showing an intake air flow in a curved portion of FIG.

FIG. 7 is a perspective view showing an example of an intake manifold for an internal combustion engine.

8 is a cross-sectional view of FIG.

9 is a cross-sectional view of the branch pipe of FIG.

FIG. 10 is an end view of the engine head mounting flange of FIG.

[Explanation of symbols]

 1 Main Pipe 10 Branch Pipe 11 One End 12 The Other End 13 Curved Part 20 Engine Head Mounting Flange 21 Mounting Part 22, 23 Channel C Centerline S1, S3 Cross Section Area of Outer Area S2, S4 Cross Section Area of Inner Area

Claims (2)

[Scope of utility model registration request] 1. A plurality of branch pipes (1) having a main pipe (1) and a bent portion whose one end (11) is connected to the main pipe (1).
0) and an engine head mounting flange (20) connected to the other end (12) of each branch pipe (10), the bent portion (13) of each branch pipe (10). Is the cross-sectional area (S1) of the region outside the center line (C) of each branch pipe (10).
Is larger than the cross-sectional area (S2) of the inner region, the intake manifold for an internal combustion engine. 2. A plurality of branch pipes (1) having a main pipe (1) and a bent portion whose one end (11) is connected to the main pipe (1).
0) and an engine head mounting flange (20) connected to the other end (12) of each branch pipe (10), the branch pipes (10) are The engine having a cross-sectional area (S3) outside the center line (C) of 10) larger than the cross-sectional area (S4) of the inside area and connected to the other end (12) of each branch pipe (10). Head mounting flange (20) mounting part (2
The flow passage (22) of 1) and the flow passage (23) of the engine head mounting flange (20) continuous with the flow passage (22) have an inner cross-sectional shape substantially the same as the port shape of the engine head. An intake manifold for an internal combustion engine.