Intake system for internal combustion engine

Abstract

To provide an intake device of an internal combustion engine, which can protect piping by preventing vehicle members installed around the internal combustion engine from interfering with the piping at the time of a vehicle collision or the like.SOLUTION: An intake device of an engine 1 includes an intake manifold 9 having a surge tank 8 and a branch pipe 9C, and a blow-by gas pipe 10 through which blow-by gas flows. When the intake manifold 6 is viewed from the arrangement direction of branch pipes 9A, 9B, 9C (the same direction as the row of cylinders), the branch pipe 9C is configured to include an upwardly-curved portion 9g that curves upward from the surge tank 8, and a downwardly-curved portion 9j that extends above the mounting flange 7 from the upwardly-curved portion 9g, then curves downward and reaches the mounting flange 7. The blow-by gas pipe 10 is installed below a virtual plane 31 that passes through the upper surface 8u of the surge tank 8 and the uppermost surfaces 9u of the branch pipes 9C.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an intake system for an internal combustion engine. [Background technology]

[0002] BACKGROUND ART An engine component arrangement structure is known that includes a PCV hose that returns blow-by gas generated in an internal combustion engine from a cylinder head cover to a surge tank of an intake manifold (see Patent Document 1).

[0003] The PCV hose extends upward from the cylinder head, passes above the branch pipe of the intake manifold, and is connected to the surge tank. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-3825 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional engine component layout structures, the PCV hose extends upward from the cylinder head, passes above the branch pipe of the intake manifold, and is connected to the surge tank. This means that in the event of a vehicle collision, the PCV hose may come into contact with vehicle components installed around the internal combustion engine, potentially subjecting the PCV hose to external force.

[0006] If an external force is applied to the PCV hose during a vehicle collision and the PCV hose is damaged, there is a risk that incomplete combustion or unburned gas may leak into the atmosphere. There is still room for improvement in terms of preventing external forces from being applied to the PCV hose.

[0007] The present invention has been made in light of the above-mentioned circumstances, and aims to provide an intake device for an internal combustion engine that can prevent vehicle components installed around the internal combustion engine from interfering with the piping in the event of a vehicle collision, etc., and protect the piping. [Means for solving the problem]

[0008] The present invention is an intake device for an internal combustion engine comprising: a surge tank; an intake manifold having a mounting flange attached to a cylinder head of an internal combustion engine; and a plurality of branch pipes arranged in parallel between the mounting flange and the surge tank; and piping through which a predetermined fluid flows, wherein, when the intake manifold is viewed from the arrangement direction of the plurality of branch pipes, the plurality of branch pipes include an upward curved portion that curves upward from the surge tank and a downward curved portion that extends from the upward curved portion above the mounting flange and then curves downward, and the piping is installed below an imaginary plane that passes through the upper surface of the surge tank and the uppermost surfaces of the plurality of branch pipes. The pipe is installed so as to pass through a space between two adjacent branch pipes among the plurality of branch pipes, and the two adjacent branch pipes have a pipe holding portion that holds the pipe, and the pipe holding portion has a U-shaped cross section and both side walls that are curved along the outer walls of the two branch pipes, and the pipe holding portion is connected to the mounting flange and formed integrally with the mounting flange, and a pair of fitting protrusions are provided on the side surfaces of the two adjacent branch pipes so as to protrude opposite each other, and the pair of fitting protrusions are provided above the pipe holding portion, and the pipe held by the pipe holding portion abuts against the pair of fitting protrusions. It is characterized by the fact that [Effects of the Invention]

[0009] As described above, according to the present invention, in the event of a vehicle collision or the like, interference of vehicle components installed around the internal combustion engine with the piping can be suppressed, thereby protecting the piping. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a plan view of an internal combustion engine equipped with an intake device according to an embodiment of the present invention. [Figure 2] 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. [Figure 3] FIG. 3 is a perspective view of an intake manifold for an internal combustion engine according to one embodiment of the present invention. [Figure 4] FIG. 4 is a plan view of an intake manifold of an internal combustion engine according to one embodiment of the present invention. [Figure 5]FIG. 5 is a front view of an intake manifold for an internal combustion engine according to one embodiment of the present invention. [Figure 6] 6 is a cross-sectional view taken along the line VI-VI in FIG. [Figure 7] 7 is a cross-sectional view taken along the line VII-VII in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] An intake device for an internal combustion engine according to one embodiment of the present invention comprises a surge tank, an intake manifold having a mounting flange attached to the cylinder head of the internal combustion engine and a plurality of branch pipes arranged in parallel between the mounting flange and the surge tank, and piping through which a predetermined fluid flows, and when the intake manifold is viewed from the direction in which the branch pipes are arranged, the branch pipes include upward curved portions that curve upward from the surge tank and downward curved portions that extend from the upward curved portion above the mounting flange and then curve downward, and the piping is installed below an imaginary plane that passes through the top surface of the surge tank and the top surfaces of the plurality of branch pipes.

[0012] As a result, the intake device for an internal combustion engine according to one embodiment of the present invention can prevent vehicle components installed around the internal combustion engine from interfering with the piping in the event of a vehicle collision, etc., thereby protecting the piping. [Example]

[0013] 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.

[0014] 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 direction) is the front / rear direction, the left / right direction of the vehicle (vehicle width direction) is the left / right direction, and the up / down direction of the vehicle (vehicle height direction) is the up / down direction.

[0015] First, the configuration will be described. 1 and 2, engine 1, which is an internal combustion engine mounted on a vehicle, includes a cylinder block 2. Cylinder block 2 includes three cylinders 2A arranged in the front-to-rear direction and a crankshaft (not shown), which also extends in the front-to-rear direction. Engine 1 in this embodiment is a longitudinally mounted engine of the FR (front engine, rear drive) type.

[0016] The 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.

[0017] The engine 1 is installed below a floor panel 32 that constitutes a vehicle member. The cylinder block 2 of this embodiment is installed so that the center lines of the multiple cylinders 2A are inclined relative to the vertical direction (up-down direction).

[0018] 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, and the like, all of which are not shown.

[0019] The intake port opens to an 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.

[0020] A cylinder head cover 4 is installed diagonally above the cylinder head 3. A blow-by gas chamber (not shown) is formed inside the cylinder head cover 4, into which blow-by gas generated in the engine 1 is introduced.

[0021] Blow-by gas refers to 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 surface of each cylinder 2A and the piston.

[0022] 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.

[0023] 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.

[0024] The cylinder head cover 4 has a lower portion 4A and a higher portion 4B that bulges obliquely upward from the lower portion 4A.

[0025] A blow-by gas outlet 4b is formed in the side wall 4a of the higher portion 4B. The center line 4s of the blow-by gas outlet 4b faces the arrangement direction L of the cylinders 2A and opens at a position adjacent to the outer peripheral surface 4c of the lower 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.

[0026] The engine 1 is provided with an intake manifold 6. The intake manifold 6 has a mounting flange 7 (see FIG. 2), and the mounting flange 7 is attached to the intake side wall 3a of the cylinder head 3.

[0027] The intake manifold 6 has a surge tank 8, which is disposed so as to face the mounting flange 7 in the horizontal direction.

[0028] The intake manifold 6 has a plurality of branch pipes 9A, 9B, and 9C, which are arranged in parallel between the mounting flange 7 and the surge tank 8.

[0029] Branch passages are formed inside the branch pipes 9A, 9B, and 9C. The upstream ends of the branch passages communicate with the surge tank 8, and the downstream ends of the branch passages communicate with the intake ports of the cylinder head 3.

[0030] 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.

[0031] An air cleaner (not shown) is provided upstream of the throttle body 21, and 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.

[0032] A blow-by gas intake port 8a is formed in the surge tank 8 (see FIGS. 3 and 4), and the blow-by gas outlet 4b and the blow-by gas intake port 8a are connected by a blow-by gas piping 10. In other words, the blow-by gas piping 10 is connected to the cylinder head cover 4 and the surge tank 8.

[0033] 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.

[0034] For example, the PCV valve 11 operates in response to the differential pressure between the blow-by gas chamber in the cylinder head cover 4 and the intake manifold 6 located downstream thereof, 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 direction in which the fluid flows.

[0035] That is, the blow-by gas pipe 10 introduces blow-by gas as a predetermined fluid from the cylinder head cover 4 to the surge tank 8.

[0036] 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. The blow-by gas pipe 10 of this embodiment constitutes a pipe.

[0037] 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.

[0038] As shown in FIGS. 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.

[0039] The upstream pipe section 10A curves from the blow-by gas outlet 4b along the outer surface 4c of the lower part 4A of the cylinder head cover 4, passes between the delivery pipe 12 and the cylinder head 3, and extends to between the upstream ends of the branch pipes 9B and 9C.

[0040] Adjacent branch pipes 9B, 9C have curved portions 9a, 9b that curve in the cylinder row direction L. Specifically, as shown in Fig. 4, adjacent branch pipes 9B, 9C are curved forward in the cylinder row direction L on their downstream sides connected to the mounting flange 7 relative to their upstream sides connected to the surge tank 8.

[0041] The portion of the branch pipe 9A that is aligned with the curved portions 9a and 9b in the cylinder row direction L extends linearly in a direction perpendicular to the cylinder row direction L.

[0042] The blow-by gas pipe 10 is covered with a protector 13, and the blow-by gas pipe 10 of 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.

[0043] The intermediate pipe portion 10B is installed so as to pass through a space 14 (see FIGS. 3 and 4) sandwiched between the branch pipes 9B and 9C on both sides in the cylinder row direction L. That is, the intermediate pipe portion 10B is installed so as to be curved along the curved portions 9a and 9b of the branch pipes 9B and 9C.

[0044] The downstream pipe section 10C extends from the downstream end 10a of the intermediate pipe section 10B to the surge tank 8 so as to be away from the space 14 of the intermediate pipe section 10B.

[0045] The two sides in the cylinder row direction L refer to the side of the intermediate pipe portion 10B facing the branch pipe 9B in the cylinder row direction L and the side of the intermediate pipe portion 10B facing the branch pipe 9C in the cylinder row direction L.

[0046] 3 and 4, a pipe holding portion 15 is provided between branch pipes 9B and 9C. Pipe holding portion 15 is connected to mounting flange 7 and is formed integrally with mounting flange 7.

[0047] 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.

[0048] 3 and 6, pipe holding portion 15 has bottom wall 15A and side walls 15B and 15C that curve upward from both ends of bottom wall 15A. Pipe holding portion 15 has a U-shaped cross section, and side walls 15B and 15C curve along the outer walls of branch pipes 9B and 9C.

[0049] As shown in Figures 3, 5, and 7, when the intake manifold 6 is viewed from the arrangement direction of the branch pipes 9A, 9B, 9C (the same direction as the cylinder row direction L), the branch pipes 9A, 9B, 9C have upward curved portions 9e, 9f, 9g that curve upward from the surge tank 8, and downward curved portions 9h, 9i, 9j that extend from the upward curved portions 9e, 9f, 9g above the mounting flange 7 and then curve downward to reach the mounting flange 7.

[0050] The pipe holding portion 15 is installed at the downward curved portions 9i and 9j, and the blow-by gas pipe 10 is sandwiched between the downward curved portions 9i and 9j in the cylinder row direction L.

[0051] 5 and 6, the blow-by gas piping 10 is installed below an imaginary plane 31 that passes through the upper surface 8u of the surge tank 8 and the uppermost surfaces 9u of the branch pipes 9A, 9B, and 9C. In the intake manifold 9 of this embodiment, the uppermost surfaces 9u of the branch pipes 9A, 9B, and 9C are the same as the uppermost surface 9u of the branch pipe 9C.

[0052] 3 and 4, fitting protrusions 9c and 9d are provided on branch pipes 9B and 9C. The fitting protrusion 9c protrudes from branch pipe 9B toward branch pipe 9C. The fitting protrusion 9d protrudes from branch pipe 9C toward branch pipe 9B and is arranged side by side with the fitting protrusion 9c in the cylinder row direction L.

[0053] 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 projections 9c and 9d, and is supported by the pipe holding portion 15.

[0054] 1 and 3, 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.

[0055] Next, the effects of the intake system of the engine 1 of this embodiment will be described. The intake system of the engine 1 of this embodiment includes a surge tank 8, a mounting flange 7 attached to the cylinder head 3 of the engine 1, an intake manifold 9 having branch pipes 9A, 9B, and 9C installed in parallel between the mounting flange 7 and the surge tank 8, and a blow-by gas pipe 10 through which blow-by gas flows.

[0056] When the intake manifold 6 is viewed from the arrangement direction of the branch pipes 9A, 9B, 9C (the same direction as the cylinder row direction L), the branch pipes 9A, 9B, 9C have upward curved portions 9e, 9f, 9g that curve upward from the surge tank 8, and downward curved portions 9h, 9i, 9j that extend from the upward curved portions 9e, 9f, 9g above the mounting flange 7 and then curve downward to reach the mounting flange 7.

[0057] The blow-by gas pipe 10 is installed below an imaginary plane 31 that passes through the upper surface 8u of the surge tank 8 and the uppermost surfaces 9u of the branch pipes 9A, 9B, and 9C.

[0058] This allows the blow-by gas piping 10 to be installed in a position where it is unlikely to interfere with the floor panel 32 installed above the intake manifold 9 in the event of a vehicle collision, as shown in FIG.

[0059] That is, the blow-by gas piping 10 can be installed at a position away from the upper surface 8u of the surge tank 8 and the uppermost surfaces 9u of the branch pipes 9A, 9B, and 9C with respect to the floor panel 32, so that the branch pipes 9A, 9B, and 9C can be made to interfere with the floor panel 32 before the floor panel 32 interferes with the blow-by gas piping 10. Therefore, interference of the floor panel 32 with the blow-by gas piping 10 can be suppressed.

[0060] Furthermore, the branch pipes 9A, 9B, and 9C can absorb the impact before the floor panel 32 interferes with the blow-by gas piping 10, and the impact applied from the floor panel 32 to the blow-by gas piping 10 can be alleviated.

[0061] As a result, it is possible to suppress the application of external force from the floor panel 32 to the blow-by gas piping 10, and it is possible to protect the blow-by gas piping 10.

[0062] Since the blow-by gas piping 10 can be protected in this manner, damage to the blow-by gas piping 10 can be prevented, and incomplete combustion or unburned gas can be prevented from being released into the atmosphere from the blow-by gas piping 10.

[0063] Furthermore, according to the intake system of the engine 1 of this embodiment, the blow-by gas pipe 10 is installed so as to pass through the space 14 sandwiched between the two adjacent branch pipes 9B and 9C.

[0064] This allows the floor panel 32 to interfere with the branch pipes 9A, 9B, and 9C before interfering with the blow-by gas piping 10 when the floor panel 32 moves downward toward the intake manifold 9 due to vehicle vibration or a vehicle collision, or when the intake manifold 9 moves upward toward the floor panel 32.

[0065] On the other hand, if other vehicle components other than the floor panel 32 are installed in the arrangement direction of the branch pipes 9A, 9B, and 9C (the same direction as the cylinder row direction L), in the event of a vehicle collision, the other vehicle components can be caused to collide with the branch pipe 9A or branch pipe 9C from the arrangement direction of the branch pipes 9A, 9B, and 9C.

[0066] This reduces interference between other vehicle components and the blow-by gas piping 10, and reduces impacts applied to the blow-by gas piping 10 by the branch pipe 9A or the branch pipe 9C when other vehicle components interfere with the blow-by gas piping 10. As a result, the blow-by gas piping 10 can be protected more effectively.

[0067] Furthermore, according to the intake device of the engine 1 of this embodiment, the adjacent branch pipes 9B, 9C have a pipe holding portion 15 that holds the blow-by gas pipe 10, and the pipe holding portion 15 has a U-shaped cross section, and the side walls 15B, 15C (both side walls) are curved along the outer walls of the branch pipes 9B, 9C.

[0068] As a result, by inserting the blow-by gas piping 10 into the piping holding portion 15, the blow-by gas piping 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.

[0069] Therefore, the blow-by gas piping 10 can be prevented from vibrating and coming into contact with the branch pipes 9B and 9C, and the durability of the blow-by gas piping 10 can be ensured.

[0070] In addition, the engine 1 of this embodiment has a cylinder head cover 4 installed on the top of the cylinder head 3.

[0071] The intake system of this embodiment has a blow-by gas pipe 10 that connects the cylinder head cover 4 and the surge tank 8 and introduces blow-by gas from the cylinder head cover 4 to the surge tank 8.

[0072] This allows the blow-by gas piping 10 to be connected to the surge tank 8 after passing through the space 14 sandwiched between two adjacent branch pipes 9B and 9C from the cylinder head cover 4, preventing the blow-by gas piping 10 from being installed at a position distant from the intake manifold 9 relative to the engine 1.

[0073] Therefore, the installation space for the blow-by gas pipe 10 can be reduced, and the installation space for the engine 1 can be reduced.

[0074] In the intake system of the engine 1 of this embodiment, the piping is configured from the blow-by gas piping 10, but the piping is not limited to the blow-by gas piping 10.

[0075] For example, the 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 evaporation fuel flows as a specified fluid, etc.

[0076] Furthermore, in the intake device of the engine 1 of this embodiment, the vehicle component is composed of the floor panel 32, but it is not limited to the floor panel, and any component that is installed around the engine 1 and has the potential to interfere with the blow-by gas piping in the event of a vehicle collision can be used.

[0077] While an embodiment of the present invention has been disclosed, it will be apparent to one skilled in the art that modifications may be made thereto without departing from the scope of the present invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0078] 1...engine (internal combustion engine), 3...cylinder head, 4...cylinder head cover, 6...intake manifold, 7...mounting flange, 8...surge tank, 8u...upper surface (upper surface of surge tank), 9A, 9B, 9C...branch pipe, 9e, 9f, 9g...upward curved portion, 9h, 9i, 9j...downward curved portion, 9u...top surface (uppermost surface of branch pipe), 10...blow-by gas piping (piping), 14...space (space sandwiched between two branch pipes), 15...piping holder, 15B, 15C...side walls (both side walls of piping holder), 32...floor panel (vehicle component)

Claims

1. an intake manifold having a surge tank, a mounting flange to be mounted on a cylinder head of an internal combustion engine, and a plurality of branch pipes arranged in parallel between the mounting flange and the surge tank; A pipe through which a predetermined fluid flows, an intake device for an internal combustion engine, the intake manifold being configured such that, when the intake manifold is viewed from a direction in which the branch pipes are arranged, the branch pipes each include 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, the piping is installed below an imaginary plane passing through an upper surface of the surge tank and uppermost surfaces of the plurality of branch pipes, The piping is installed so as to pass through a space between two adjacent branch pipes among the plurality of branch pipes, The two adjacent branch pipes each have a pipe holding portion that holds the pipe, The pipe holding portion has a U-shaped cross section and both side walls are curved along the outer walls of the two branch pipes, The pipe holding portion is connected to the mounting flange and is formed integrally with the mounting flange, A pair of fitting projections are provided on the side surfaces of the two adjacent branch pipes so as to protrude opposite each other, The pair of fitting projections are provided above the pipe holding portion, 2 is a perspective view of an intake system for an internal combustion engine according to the first embodiment of the present invention;

2. The internal combustion engine has a cylinder head cover provided on an upper portion of the cylinder head, the piping is composed of a blow-by gas piping that connects the cylinder head cover and the surge tank, 2. The intake system of an internal combustion engine according to claim 1, wherein the predetermined fluid is blow-by gas introduced into the surge tank from the cylinder head cover.

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