JP7537337B2 - Intake system for internal combustion engine - Google Patents

Description

The present invention relates to an intake system for an internal combustion engine.

Conventionally, an intake manifold for an internal combustion engine is known in which piping such as blow-by gas piping is supported on the intake manifold (see Patent Document 1).

This intake manifold for an internal combustion engine has multiple branch pipes, with two adjacent branch pipes connected by a bridge section, and a holder that holds the piping is attached to the bridge section.

JP 2012-215132 A

However, conventional intake manifolds for internal combustion engines are structured so that the piping is supported by a holder with a cylindrical holding portion attached to a bridge portion, making it difficult to accurately position the piping in the space between two branch pipes whose passage shapes are complexly curved.

Therefore, if the piping is not positioned accurately, it may vibrate and come into contact with the branch pipe, reducing the durability of the piping.

The present invention was made in light of the above-mentioned circumstances, and aims to provide an intake device for an internal combustion engine that can install piping in the space between two branch pipes that are curved in a complex manner while ensuring the durability of the piping in an intake manifold that has multiple branch pipes arranged in parallel.

The present invention is an intake system for an internal combustion engine having a cylinder block with multiple cylinders and a cylinder head attached to the cylinder block, comprising a surge tank, a mounting flange attached to the cylinder head, and multiple branch pipes installed in parallel between the mounting flange and the surge tank, an intake manifold in which at least two adjacent branch pipes among the multiple branch pipes have curved portions that curve in the cylinder row direction, a pipe installed in the space between the two branch pipes and through which a predetermined fluid flows, and a pipe holder that holds the pipe in the intake manifold, the pipe holder having a U-shaped cross section and both side walls curved along the outer walls of the two branch pipes.

In this way, according to the present invention, in an intake manifold having multiple branch pipes arranged in parallel, it is possible to install piping in the space between two branch pipes that are curved in a complex manner while ensuring the durability of the piping.

FIG. 1 is a plan view of an internal combustion engine equipped with an intake system according to an embodiment of the present invention. FIG. 2 is a plan view of an intake manifold and blow-by gas piping of an internal combustion engine according to one embodiment of the present invention. FIG. 3 is a perspective view of an intake manifold for an internal combustion engine according to one embodiment of the present invention. FIG. 4 is a plan view of an intake manifold of an internal combustion engine according to one embodiment of the present invention. FIG. 5 is a front view of an intake manifold for an internal combustion engine according to one embodiment of the present invention. FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG.

The intake device of an internal combustion engine according to one embodiment of the present invention is an intake device for an internal combustion engine having a cylinder block with multiple cylinders and a cylinder head attached to the cylinder block, and includes a surge tank, a mounting flange attached to the cylinder head, and multiple branch pipes installed in parallel between the mounting flange and the surge tank, an intake manifold in which at least two adjacent branch pipes among the multiple branch pipes have curved portions that curve in the cylinder row direction, a pipe installed in the space between the two branch pipes and through which a predetermined fluid flows, and a pipe holder that holds the pipe in the intake manifold, the pipe holder having a U-shaped cross section and both side walls curved along the outer walls of the two branch pipes.

As a result, in an intake system for an internal combustion engine according to one embodiment of the present invention, in an intake manifold having multiple branch pipes arranged in parallel, it is possible to install piping in the space between two branch pipes that are curved in a complex manner while ensuring the durability of the piping.

An intake system for an internal combustion engine according to an embodiment of the present invention will now be described with reference to the drawings.
1 to 7 are diagrams showing an intake system for an internal combustion engine according to one embodiment of the present invention.

In Figures 1 to 7, the up/down, front/rear, left/right directions are based on the internal combustion engine mounted on the vehicle, and the front/rear direction of the vehicle (straight ahead) is the front/rear direction, the left/right direction of the vehicle (width direction of the vehicle) is the left/right direction, and the up/down direction of the vehicle (height direction of the vehicle) is the up/down direction.

First, the configuration will be described.
1, engine 1 as an internal combustion engine mounted on a vehicle includes a cylinder block 2. Cylinder block 2 includes three cylinders 2A arranged in the front-rear direction and a crankshaft (not shown), which also extends in the front-rear direction. Engine 1 in this embodiment is a front-engine, rear-wheel drive (FR) type engine mounted vertically.

Note that engine 1 is not limited to an in-line three-cylinder engine, but may be, for example, a V-type engine, and the number of cylinders is not limited to three.

The engine 1 is installed under a floor panel of a vehicle (not shown). In this embodiment, the cylinder block 2 is installed so that the center lines of the multiple cylinders 2A are inclined relative to the vertical direction (up-down direction).

A cylinder head 3 is provided diagonally above the cylinder block 2. The cylinder head 3 has an intake port, an exhaust port, an intake valve that opens and closes the intake port, an exhaust valve that opens and closes the exhaust port, etc. (not shown).

The intake port opens into the intake side wall 3a of the cylinder head 3, and the cylinder head 3 is installed so that the intake side wall 3a faces upward.

A cylinder head cover 4 is installed diagonally above the cylinder head 3. Inside the cylinder head cover 4, a blow-by gas chamber (not shown) is formed into which blow-by gas generated in the engine 1 is introduced.

Blow-by gas is incompletely burned or unburned gas that flows from the combustion chamber into the crankcase 2K of the cylinder block 2 through the gap between the wall of each cylinder 2A and the piston.

The cylinder block 2 is formed with a blow-by gas passage (not shown) that connects the inside of the crankcase 2K with the blow-by gas chamber of the cylinder head cover 4, and the blow-by gas that accumulates in the crankcase 2K flows into the blow-by gas chamber through the blow-by gas passage.

An oil pan 5 is installed below the cylinder block 2, and oil for lubricating the engine 1 is stored in the oil pan 5.

The cylinder head cover 4 has a low portion 4A and a high portion 4B that bulges diagonally upward from the low portion 4A.

A blow-by gas outlet 4b is formed in the side wall 4a of the high portion 4B. The blow-by gas outlet 4b has a center line 4s that faces the arrangement direction L of the cylinders 2A and opens at a position adjacent to the outer circumferential surface 4c of the low portion 4A of the cylinder head cover 4. Hereinafter, the arrangement direction L of the cylinders 2A will be referred to as the cylinder row direction L.

The engine 1 is provided with an intake manifold 6. The intake manifold 6 has a mounting flange 7 (see FIG. 2), which is attached to the intake side wall 3a of the cylinder head 3.

The intake manifold 6 has a surge tank 8, which is installed horizontally opposite the mounting flange 7 (see Figure 5).

The intake manifold 6 has multiple branch pipes 9A, 9B, and 9C, which are arranged in parallel between the mounting flange 7 and the surge tank 8.

Branch passages are formed inside the branch pipes 9A, 9B, and 9C. The upstream ends of the branch passages are connected to the surge tank 8, and the downstream ends of the branch passages are connected to the intake port of the cylinder head 3.

A throttle body 21 is connected to the upstream end of the intake manifold 6. The throttle body 21 houses a throttle valve (not shown), which adjusts the amount of intake air by adjusting the opening of the intake passage inside the throttle body 21.

An air cleaner (not shown) is provided upstream of the throttle body 21, and the intake air purified by the air cleaner is supplied to each intake port of the cylinder head 3 through the throttle body 21 and the intake manifold 6.

The surge tank 8 is formed with a blow-by gas intake 8a (see Figures 3 and 4), and the blow-by gas outlet 4b and the blow-by gas intake 8a are connected by a blow-by gas pipe 10. In other words, the blow-by gas pipe 10 is connected to the cylinder head cover 4 and the surge tank 8.

Specifically, a PCV (Positive Crankcase Ventilation) valve 11 is attached to the blow-by gas outlet 4b, and the upstream end of the blow-by gas pipe 10 is connected to the PCV valve 11.

As an example, the PCV valve 11 operates according to the pressure difference between the blow-by gas chamber in the cylinder head cover 4 and the intake manifold 6 downstream of it, and when the valve is opened, it introduces the blow-by gas in the blow-by gas chamber into the surge tank 8. Here, upstream and downstream refer to the upstream and downstream of the gas flow direction.

The blow-by gas introduced into the surge tank 8 is introduced into the combustion chamber of the cylinder 2A through the branch pipes 9A, 9B, and 9C and the intake port, and is burned in the combustion chamber. In this embodiment, the blow-by gas pipe 10 constitutes a pipe, and the blow-by gas constitutes a predetermined fluid.

A cooling pipe 16 is installed below the branch pipes 9A, 9B, and 9C. The cooling pipe 16 connects the cylinder head 3 to a radiator (not shown), and returns hot water discharged from a water jacket (not shown) of the cylinder head 3 to the radiator.

A delivery pipe 12 is attached to the cylinder head cover 4. The delivery pipe 12 supplies fuel stored in a fuel tank (not shown) to an injector (not shown) installed in the cylinder 2A.

As shown in Figures 1 and 2, the blow-by gas piping 10 has an upstream pipe section 10A, an intermediate pipe section 10B, and a downstream pipe section 10C.

The upstream pipe section 10A curves from the blow-by gas outlet 4b along the outer peripheral surface 4c of the lower portion 4A of the cylinder head cover 4, passing between the delivery pipe 12 and the cylinder head 3, and extending to between the upstream ends of the branch pipes 9B and 9C.

The adjacent branch pipes 9B, 9C have curved portions 9a, 9b that curve in the cylinder row direction L. Specifically, as shown in FIG. 4, the adjacent branch pipes 9B, 9C are curved forward in the cylinder row direction L on the downstream side connected to the mounting flange 7 relative to the upstream side connected to the surge tank 8.

The curved portions 9a and 9b and the portion of the branch pipe 9A aligned in the cylinder row direction L extend linearly in a direction perpendicular to the cylinder row direction L.

The blow-by gas pipe 10 is covered with a protector 13, and the blow-by gas pipe 10 in this embodiment includes the protector 13. Hereinafter, the blow-by gas pipe 10 and the protector 13 will be described as the blow-by gas pipe 10.

The intermediate pipe section 10B is installed in a space 14 (see Figures 3 and 4) that is sandwiched between the branch pipes 9B and 9C on both sides in the cylinder row direction L. In other words, the intermediate pipe section 10B is installed curved along the curved sections 9a and 9b of the branch pipes 9B and 9C.

The downstream pipe section 10C extends from the downstream end 10a of the intermediate pipe section 10B to the surge tank 8, away from the space 14 of the intermediate pipe section 10B.

The two sides in the cylinder row direction L refer to the side of the intermediate pipe section 10B facing the branch pipe 9B in the cylinder row direction L, and the side of the intermediate pipe section 10B facing the branch pipe 9C in the cylinder row direction L.

As shown in Figures 3 and 4, a pipe holder 15 is provided between the branch pipes 9B and 9C. The pipe holder 15 is connected to the mounting flange 7 and is formed integrally with the mounting flange 7.

The pipe holding portion 15 extends along the intermediate pipe portion 10B of the blow-by gas pipe 10 and is formed in a U-shape into which the intermediate pipe portion 10B can be inserted.

Specifically, as shown in Figs. 3 and 6, the pipe holder 15 has a bottom wall 15A and side walls 15B and 15C that curve upward from both ends of the bottom wall 15A. The pipe holder 15 has a U-shaped cross section, and the side walls 15B and 15C curve along the outer walls of the branch pipes 9B and 9C.

As shown in Figures 5 and 7, when the intake manifold 6 is viewed from the direction in which the branch pipes 9A, 9B, and 9C are arranged (the same direction as the cylinder row direction L), the branch pipes 9B and 9C have upwardly curved portions 9e and 9f that curve upward from the surge tank 8, and downwardly curved portions 9g and 9h that extend from the upwardly curved portions 9e and 9f above the mounting flange 7 and then curve downward to reach the mounting flange 7.

The pipe holding portion 15 is installed between the downward curved portions 9g and 9h, and the blow-by gas pipe 10 is sandwiched between the downward curved portions 9g and 9h in the cylinder row direction L.

As shown in Figures 2 to 4, the branch pipes 9B and 9C are provided with fitting protrusions 9c and 9d. The fitting protrusion 9c protrudes from the branch pipe 9B toward the branch pipe 9C. The fitting protrusion 9d protrudes from the branch pipe 9C toward the branch pipe 9B and is arranged side by side with the fitting protrusion 9c in the cylinder row direction L.

As shown in FIG. 2, the blow-by gas pipe 10 inserted into the pipe holding portion 15 is prevented from slipping out of the pipe holding portion 15 by abutting against the fitting protrusions 9c and 9d, and is supported by the pipe holding portion 15.

Next, the effects of the intake system of the engine 1 according to this embodiment will be described.
The intake system of the engine 1 of this embodiment is equipped with an intake manifold 6 which has a surge tank 8, a mounting flange 7 which is attached to the cylinder head 3, and branch pipes 9A, 9B, and 9C which are installed in parallel between the mounting flange 7 and the surge tank 8, with the adjacent branch pipes 9B, 9C having curved portions which curve in the direction of the cylinder row.

The intake system of the engine 1 of this embodiment also includes a blow-by gas pipe 10 that is installed in the space 14 between the branch pipes 9B and 9C, and a pipe holder 15 that holds the blow-by gas pipe 10 in the intake manifold 6. The pipe holder 15 has a U-shaped cross section, and the side walls 15B and 15C (both side walls) are curved along the outer walls of the branch pipes 9B and 9C.

As a result, by inserting the blow-by gas pipe 10 into the pipe holding portion 15, the blow-by gas pipe 10 can be accurately positioned in the space 14 between the branch pipes 9B and 9C, which have curved portions 9a and 9b that curve in the cylinder row direction L.

This prevents the blow-by gas piping 10 from vibrating and coming into contact with the branch pipes 9B and 9C, ensuring the durability of the blow-by gas piping 10.

In other words, the intake system of the engine 1 of this embodiment has an intake manifold 6 equipped with branch pipes 9B and 9C arranged in parallel, and the blow-by gas pipe 10 can be installed in the space 14 between the complexly curved branch pipes 9B and 9C while ensuring the durability of the blow-by gas pipe 10.

In the intake manifold 6 of this embodiment, adjacent branch pipes 9B and 9C have curved portions 9a and 9b that curve in the cylinder row direction, but adjacent branch pipes 9A and 9B may have curved portions that curve in the cylinder row direction, or adjacent branch pipes 9A, 9B, and 9C may have curved portions that curve in the cylinder row direction.

In this case, the blow-by gas pipe 10 may be installed in the space between the branch pipes 9A and 9B.

In addition, according to the intake device of the engine 1 of this embodiment, when the intake manifold 6 is viewed from the arrangement direction of the branch pipes 9B, 9C (the same direction as the cylinder row direction L), the branch pipes 9B, 9C have upward curved portions 9e, 9f that curve upward from the surge tank 8, and downward curved portions 9g, 9h that extend from the upward curved portions 9e, 9f above the mounting flange 7 and then curve downward to reach the mounting flange 7, and the pipe holder 15 is installed between the downward curved portions 9g, 9h.

As a result, the downward curved portions 9g and 9h can be used to support the pipe holding portion 15 on the downward curved portions 9g and 9h, and the blow-by gas pipe 10 can be supported on the pipe holding portion 15 by being sandwiched between the downward curved portions 9g and 9h.

In addition, according to the intake device of the engine 1 of this embodiment, the pipe holding portion 15 is connected to the mounting flange 7. This prevents the blow-by gas pipe 10 from contacting the corners of the mounting flange 7 when the blow-by gas pipe 10 vibrates, and protects the blow-by gas pipe 10.

In addition, the mounting flange 7 and the pipe holding portion 15 can be attached to the branch pipes 9A, 9B, and 9C as a single unit, improving the workability of assembling the intake manifold 6.

In the intake system of the engine 1 in this embodiment, the piping is composed of the blow-by gas piping 10, but the piping is not limited to the blow-by gas piping 10.

For example, piping may be applied to a breather hose that adjusts the internal pressure of the engine 1 and through which air flows as a specified fluid, a fuel pipe that connects the delivery pipe 12 to a fuel tank and through which fuel flows as a specified fluid, a purge hose that connects the engine 1 to a canister (not shown) and through which deposition fuel flows as a specified fluid, etc.

Although an embodiment of the present invention has been disclosed, it is apparent that modifications may be made by one of ordinary skill in the art without departing from the scope of the present invention. All such modifications and equivalents are intended to be included in the following claims.

1...Engine (internal combustion engine), 2...Cylinder block, 2A...Cylinder, 3...Cylinder head, 6...Intake manifold, 7...Mounting flange, 8...Surge tank, 9A, 9B, 9C...Branch pipe, 9g, 9h...Downward curved portion, 10...Blow-by gas pipe (piping), 14...Space (space between two branch pipes), 15...Pipe holder, 15B, 15C...Side walls (both sides of the pipe holder)

Claims (3)

An intake system for an internal combustion engine having a cylinder block having a plurality of cylinders and a cylinder head attached to the cylinder block,
an intake manifold including a surge tank, a mounting flange attached to the cylinder head, and a plurality of branch pipes arranged in parallel between the mounting flange and the surge tank, at least two adjacent branch pipes among the plurality of branch pipes having curved portions curved in a cylinder row direction;
a pipe that is installed in a space between the two branch pipes and through which a predetermined fluid flows;
a pipe holding portion that holds the pipe in the intake manifold,
2. An intake system for an internal combustion engine, wherein the pipe holding portion has a U-shaped cross section and both side walls thereof are curved along outer walls of the two branch pipes. When the intake manifold is viewed from a direction in which the two branch pipes are arranged, the two branch pipes have an upward curved portion that curves upward from the surge tank, and a downward curved portion that extends from the upward curved portion to a position above the mounting flange and then curves downward,
2. The intake system of an internal combustion engine according to claim 1, wherein the pipe holding portion is disposed between the downward curved portions. The intake device for an internal combustion engine according to claim 1 or 2, characterized in that the pipe holding portion is connected to the mounting flange.

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