JP5534855B2 - engine - Google Patents

Description

  The present invention relates to the technology of an engine having a plurality of cylinders. More specifically, the present invention relates to a technique for reducing fuel consumption of an engine having a plurality of cylinders and reducing environmental load substances contained in exhaust gas.

  2. Description of the Related Art Conventionally, an engine that is operated by mixing a combustible gas such as natural gas or city gas with air and burning the mixture is known. In such an engine, combustible gas and air are mixed and then distributed to the combustion chamber of each cylinder, and the engine is operated by sequentially burning each cylinder.

  However, in an engine having a plurality of cylinders, pulsation caused by the operation cycle of each cylinder is generated inside the intake manifold, so that the combustible gas and air are uniformly mixed and then uniformly distributed to the combustion chamber of each cylinder. In some cases, it is difficult to distribute the fuel, and the combustion stroke between the cylinders may vary (see, for example, Patent Document 1).

  This is because if the mixture of combustible gas and air becomes uneven, the air-fuel ratio (ratio of combustible gas amount to air amount) of the air-fuel mixture introduced into the combustion chamber becomes unstable, and This is because if the distribution becomes uneven, the amount of air-fuel mixture introduced into the combustion chamber becomes unstable. In such a case, a difference occurs in the amount of heat generated by the combustion of the air-fuel mixture, resulting in an increase in fuel consumption and an increase in environmentally hazardous substances.

JP 2008-32027 A

  The present invention has been made to solve such a problem, and an air-fuel mixture obtained after uniformly mixing a combustible gas and air is evenly distributed to the combustion chambers of the respective cylinders. An object of the present invention is to provide a technique for suppressing variations in combustion stroke, reducing engine fuel consumption, and reducing environmentally hazardous substances contained in exhaust.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

The engine according to claim 1, further comprising an intake manifold (24) fixed to the cylinder head (12) and guiding the air-fuel mixture to the combustion chamber (15), wherein the air intake manifold (24) A collecting portion (241) for storing, and a branch pipe portion (242) for distributing the air-fuel mixture stored in the collecting portion (241) to the combustion chamber (15), the collecting portion (241) The branch pipe portion (242) is formed integrally with a mold, and the internal space of the collective portion (241) is the internal space of each branch pipe (242A) constituting the branch pipe portion (242). Are separated by a wall surface (24w), and the inner space of the assembly portion (241) and the branch tube (242A) are located at a position where the flow path length of the branch tube (242A) of the wall surface (24w) is the longest. ) Communication port (24h) communicating with the interior space In order to guide the air-fuel mixture stored in the collecting portion (241) to the communication port (24h), the communication port (24h) of the wall surface (24w) is connected to the inner space side of the collecting portion (241). A protruding guide passage (243) is provided, and an inner space of the guide passage (243), an inner space of the gathering portion (241), and a peripheral wall surface at the position of the wall surface (24w) of the guide passage (243) Are provided, and an oil passage (243h) through which oil passes is provided .

According to Claim 2, in the engine according to Claim 1, a wall surface (24w) that separates the internal space of the collecting portion (241) from the internal space of the branch pipe (242A) is provided as the communication port (24h). It is formed so as to incline with a downward slope toward the .

According to a third aspect of the present invention, in the engine according to the first or second aspect, the intake manifold (24) is located at a position farthest from the communication port (24h) in the collecting portion (241). 18) is arranged .

  As effects of the present invention, the following effects can be obtained.

  According to the first aspect of the present invention, the air-fuel mixture obtained after uniformly mixing the combustible gas and air can be evenly distributed to the combustion chambers of the respective cylinders. As a result, variations in the combustion stroke between the cylinders can be suppressed, and it is possible to reduce the fuel consumption of the engine and the environmental load substances contained in the exhaust.

In the intake manifold 24 provided in the engine 100, since the inner space of the collecting portion 241 and the inner space of the branch pipe 242A are separated by the wall surface 24w, the mold Mn1 forming the upper surface and the side surface of the collecting portion 241 is used. The mold Mn2 that is separated in the upward direction and forms the lower surface and the side surface of the branch pipe portion 242 can be manufactured only by separating in the downward direction.

In other words, the intake manifold 24 in which the inner space of the collecting portion 241 and the inner space of the branch pipe 242A are separated by the wall surface 24w can be manufactured with two molds Mn1 and Mn2, and further, the molds Mn1 and Mn2 are vertically moved. It can be manufactured by separating into two.

As described above, the intake manifold 24 provided in the engine 100 can reduce the number of molds required at the time of manufacturing the intake manifold 24, and the separation of the respective molds is simple. This makes it possible to reduce costs.

Further, the air-fuel mixture obtained after uniformly mixing the combustible gas and air can be evenly distributed to the combustion chambers of the respective cylinders with high accuracy.
As a result, variations in the combustion stroke between the cylinders can be suppressed, and it is possible to reduce the fuel consumption of the engine and the environmental load substances contained in the exhaust.

Further, the air-fuel mixture obtained after the combustible gas and air are uniformly mixed can be evenly distributed to the combustion chambers of the respective cylinders with higher accuracy.
As a result, variations in the combustion stroke between the cylinders can be suppressed, and it is possible to reduce the fuel consumption of the engine and the environmental load substances contained in the exhaust.

Further, the air-fuel mixture obtained after the combustible gas and air are uniformly mixed can be evenly distributed to the combustion chambers of the respective cylinders with higher accuracy.
Further, it is possible to prevent the tar contained in the combustible gas and the oil contained in the blow-by gas from accumulating inside the intake manifold, and to prevent the tar and oil from being biased toward the combustion chamber of a certain cylinder. As a result, variations in the combustion stroke between the cylinders can be suppressed, and it is possible to reduce the fuel consumption of the engine and the environmental load substances contained in the exhaust.

According to the second aspect of the present invention, the tar contained in the combustible gas and the oil contained in the blow-by gas are prevented from accumulating inside the intake manifold, and the tar or oil is biased to the combustion chamber of a certain cylinder. Can be prevented. As a result, variations in the combustion stroke between the cylinders can be suppressed, and it is possible to reduce the fuel consumption of the engine and the environmental load substances contained in the exhaust.

According to the third aspect of the present invention, noise can be prevented from entering the detection signal from the sensor, and the detection accuracy can be improved.

Schematic which shows the whole structure of the engine which concerns on this invention. 1 is a side sectional view of an engine according to the present invention. The perspective view of an intake manifold. The perspective sectional view of an intake manifold. Side surface sectional drawing of an intake manifold. (A) Schematic which shows the manufacturing process of an intake manifold. (B) Schematic showing the manufacturing process of another intake manifold.

  The overall configuration of the engine 100 according to the present invention will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a schematic diagram showing an overall configuration of an engine 100 according to the present invention, and FIG. 2 is a side sectional view thereof. The white arrows in the figure indicate the air sucked from the outside and the flow of the air-fuel mixture introduced into the combustion chamber 15 of each cylinder, and the black arrows in the figure indicate the combustion chambers of each cylinder. 15 shows the flow of exhaust gas discharged from 15. Also, the front / rear and left / right directions of the engine 100 are shown in FIG. 1, and the direction of gravity action is shown in FIG.

  The engine 100 according to the present invention is a reciprocating internal combustion engine that is operated by mixing a combustible gas such as natural gas or city gas with air and sequentially burning the mixture for each cylinder. The engine 100 mainly includes an engine main body portion 1, an intake passage portion 2, and an exhaust passage portion 3.

  First, the engine main body 1 will be described in detail.

  The engine main body 1 is mainly composed of a cylinder block 11, a cylinder head 12, a piston 13, and a crankshaft 14.

  The cylinder block 11 forms a main structure of the engine main body 1. The cylinder block 11 is provided with a cylinder 11a in the vertical direction. A piston 13 is slidably provided in the cylinder 11a. The engine 100 according to the present invention is a so-called in-line four-cylinder engine in which four cylinders 11a are provided in series.

  The cylinder head 12 is fixed to the upper end surface of the cylinder block 11 and constitutes a combustion chamber 15 between the cylinder head 12 and a piston 13 provided in the cylinder 11a. The cylinder head 12 is provided with an intake port 12a for introducing an air-fuel mixture to the combustion chamber 15 and an intake valve 12A that can open and close the flow path of the intake port 12a. Further, the cylinder head 12 is provided with an exhaust port 12b for exhausting exhaust gas from the combustion chamber 15, and provided with an exhaust valve 12B capable of opening and closing the flow path of the exhaust port 12b. Note that the spark plug 16 is attached to the cylinder head 12 so that the tip of the spark plug 16 protrudes into the combustion chamber 15.

  The piston 13 transmits expansion energy generated in the combustion chamber 15 to the crankshaft 14 by sliding the cylinder 11 a of the cylinder block 11 in the vertical direction. The piston 13 is provided with a piston pin 131 so as to be perpendicular to the central axis of the cylinder 11 a and to be parallel to the rotation axis of the crankshaft 14.

  The crankshaft 14 converts the sliding motion of the piston 13 into a rotational motion. In the crankshaft 14, the crankpin 141 provided in parallel to the rotation axis of the crankshaft 14 and the piston pin 131 of the piston 13 are connected by the connecting rod 17, so that the sliding motion of the piston 13 is turned into a rotational motion. Can be converted.

  Next, the intake passage portion 2 will be described in detail.

  The intake passage portion 2 mainly includes an intake pipe 21, an air cleaner 22, a mixer 23, and an intake manifold 24.

  The intake pipe 21 is a passage that guides air sucked from the outside to the mixer 23. The intake pipe 21 is provided with an air cleaner 22 in the middle of the intake pipe 21, and a mixer 23 is connected to the downstream end of the intake pipe 21. The intake pipe 21 is provided with an intake flow rate sensor for measuring the amount of intake air, but is omitted in this figure for simplicity.

  The air cleaner 22 performs filtration of air sucked from the outside. The air cleaner 22 filters inhaled air by passing a filter paper or sponge, and prevents foreign matters such as dust from entering the combustion chamber 15.

  The mixer 23 supplies combustible gas such as natural gas or city gas to the sucked air and mixes them. The mixer 23 generates an air-fuel mixture according to the operating state of the engine 100 in order to adjust the supply amount of the combustible gas according to the air amount guided by the intake pipe 21.

  The intake manifold 24 guides the air-fuel mixture generated by the mixer 23 to the combustion chamber 15 of each cylinder. As described above, since the engine 100 according to the present invention is an in-line four-cylinder engine including the four combustion chambers 15, the intake manifold 24 is formed to branch toward the respective combustion chambers 15. The intake manifold 24 is connected to a blow-by passage 25 that guides air discharged from the cylinder block 11 (hereinafter referred to as “blow-by gas”) in order to reduce the internal pressure of the cylinder block 11.

  Next, the exhaust passage portion 3 will be described in detail.

  The exhaust passage portion 3 is mainly composed of an exhaust manifold 31, an exhaust pipe 32, and an exhaust purification device 33.

  The exhaust manifold 31 guides the exhaust discharged from the combustion chamber 15 of each cylinder to the exhaust pipe 32. The exhaust manifold 31 is formed so as to join the exhaust discharged from the respective combustion chambers 15.

  The exhaust pipe 32 is a passage that guides the exhaust gas guided by the exhaust manifold 31 to the exhaust gas purification device 33. The exhaust pipe 32 has an exhaust manifold 31 connected to an upstream end portion of the exhaust pipe 32 and an exhaust purification device 33 connected to a downstream end portion of the exhaust pipe 32. The exhaust pipe 32 is provided with an exhaust temperature sensor for measuring the temperature of the exhaust, but is omitted in the drawing for the sake of simplicity.

  The exhaust gas purification device 33 oxidizes and removes CO (carbon monoxide) and HC (hydrocarbon) contained in the exhaust gas by an oxidation catalyst carrier. The oxidation catalyst carrier is obtained by carrying platinum or the like on a base material such as silicon carbide, and performs the above oxidation reaction by a catalytic action of platinum or the like.

  The above is the overall configuration of the engine 100 according to the present invention. Next, the intake manifold 24 of the engine 100 will be described in more detail with reference to FIGS. 3, 4, and 5.

  FIG. 3 is a perspective view of the intake manifold 24, and FIG. 4 is a perspective sectional view thereof. FIG. 5 is a side sectional view of the intake manifold 24. The white arrows shown in FIG. 5 indicate the flow of the air-fuel mixture guided to the combustion chamber 15. Further, the front / rear and left / right directions of the intake manifold 24 are shown in FIGS. 3 and 4, and the direction of gravity is shown in FIG.

  As described above, the intake manifold 24 guides the air-fuel mixture generated by the mixer 23 to the combustion chamber 15 of each cylinder. The intake manifold 24 is mainly composed of a collecting portion 241 and a branch pipe portion 242.

  The collecting unit 241 stores the air-fuel mixture generated by the mixer 23. The collecting portion 241 has a large volume so as not to cause a shortage in the stored air-fuel mixture even in any operating state of the engine 100. In addition, the mixer 23 will be arrange | positioned at the front side surface of the gathering part 241 (refer FIG. 1).

  The branch pipe part 242 distributes the air-fuel mixture stored in the collecting part 241 to the combustion chamber 15 of each cylinder. The branch pipe part 242 extends from the lower side of the collecting part 241 toward the left, and the downstream end of each branch pipe 242A, 242A. Are communicated with each of the intake ports 12a, 12a... (See FIG. 5).

  Further, the inner space of the collecting portion 241 is separated from the inner space of each branch pipe 242A, 242A... Constituting the branch pipe portion 242 by the wall surface 24w, and the wall surface 24w includes the inner space of the collecting portion 241 and each space. Communication ports 24h, 24h,... That communicate with the internal space of the branch pipes 242A, 242A,. As a result, the air-fuel mixture stored in the collecting portion 241 flows into the branch pipes 242A, 242A,... From the communication ports 24h, 24h, and so on and is guided to the combustion chamber 15 of each cylinder. The communication ports 24h, 24h,... Are provided on the right side of the lower surface (wall surface 24w) of the collecting portion 241, and are provided at regular intervals in the front-rear direction (see FIG. 4).

  By adopting such a configuration, the intake manifold 24 can be arranged in a state in which the collecting portion 241 and the branch pipe portion 242 are in contact with each other, and has an overall width (see W in FIG. 5) and an overall height (see H in FIG. 5). ) Can be made smaller. As a result, the engine 100 including the intake manifold 24 can be reduced in size, and the mountability can be improved.

  In addition, the intake manifold 24 can diffuse the combustible gas in the internal space of the collecting portion 241 even when the mixture of the combustible gas and the air generated by the mixer 23 is insufficient. It is possible to make the mixing of combustible gas and air uniform.

  Further, the intake manifold 24 can reduce the pulsation generated due to the operation cycle of each cylinder by the collecting portion 241 having a large internal space volume, and the air-fuel mixture stored in the collecting portion 241 is burned in each cylinder. It is possible to distribute evenly to the chambers 15.

  Here, an aspect in which pulsation occurs inside the intake manifold 24 due to the operation cycle of each cylinder will be described, and the reason why the intake manifold 24 can evenly distribute the air-fuel mixture to the combustion chambers 15 of each cylinder. This will be described in detail.

  The engine 100 according to the present invention is a four-cycle engine whose operation cycle includes four strokes of an intake stroke, a compression stroke, a combustion stroke, and an exhaust stroke. Therefore, the engine 100 completes the above strokes while the crankshaft 14 makes two revolutions, and operates by repeating this.

  The intake stroke is a stroke in which the air-fuel mixture is sucked into the combustion chamber 15 by opening the intake valve 12A provided in the cylinder head 12 and sliding the piston 13 downward. The engine 100 proceeds to the compression stroke after the piston 13 reaches the bottom dead center and completes the intake of the air-fuel mixture.

  The compression stroke is a stroke in which the air-fuel mixture in the combustion chamber 15 is compressed by closing the intake valve 12A provided in the cylinder head 12 and sliding the piston 13 upward. The engine 100 shifts to the combustion stroke by igniting the compressed air-fuel mixture with the spark plug 16.

  The combustion stroke is a stroke in which the piston 13 is pushed down by using the expansion energy, that is, the pressure rise due to the combustion of the air-fuel mixture, and the rotational power is applied to the crankshaft 14. The engine 100 proceeds to the exhaust stroke after the piston 13 reaches the bottom dead center and completes the application of rotational power.

  The exhaust stroke is a stroke in which exhaust in the combustion chamber 15 is discharged by opening the exhaust valve 12B provided in the cylinder head 12 and sliding the piston 13 upward. Then, the engine 100 shifts to the intake stroke again after the piston 13 reaches the top dead center and completes exhaust emission.

  As described above, the engine 100 that operates by repeating the above-described strokes intermittently sucks the air-fuel mixture during the intake stroke of the operation cycle, and as a result, pulsation occurs in the intake manifold 24. It was.

  However, since the intake manifold 24 provided in the engine 100 has the collecting portion 241 that secures a large volume of the internal space, the pulsation can be attenuated by the collecting portion 241 and led to the combustion chamber 15 of each cylinder. It is possible to reduce variation in the amount of air-fuel mixture. That is, the intake manifold 24 not only uses the collecting portion 241 for storing the air-fuel mixture, but also can attenuate the pulsation by functioning as a surge tank, whereby the air-fuel mixture stored in the collecting portion 241 can be reduced. It is possible to distribute evenly to the combustion chambers 15 of the cylinders.

  With the configuration as described above, the air-fuel mixture obtained after the combustible gas and air are uniformly mixed can be evenly distributed to the combustion chambers 15 of the respective cylinders. As a result, variations in the combustion stroke between the cylinders can be suppressed, and it becomes possible to reduce the fuel consumption of the engine 100 and the environmental load substances contained in the exhaust.

  As shown in FIGS. 4 and 5, the intake manifold 24 provided in the engine 100 is provided with a communication port 24h at a position farthest from the downstream end of the branch pipe 242A in the wall surface 24w. That is, the intake manifold 24 is provided with the communication port 24h at a position where the flow path length of the branch pipe 242A is longest in a side view.

  As described above, the intake manifold 24 can suppress the turbulence of the air-fuel mixture flowing inside it by increasing the flow path length of the branch pipe 242A, and can rectify the flow of the air-fuel mixture. It is said. In this way, the intake manifold 24 can distribute the air-fuel mixture flowing into the branch pipes 242A, 242A... From the collecting portion 241 to the combustion chambers 15 of the respective cylinders without variation.

  With the above-described configuration, the intake manifold 24 can evenly distribute the air-fuel mixture obtained after uniformly mixing the combustible gas and air to the combustion chambers 15 of the respective cylinders with high accuracy. . As a result, the engine 100 can suppress variations in the combustion stroke between the cylinders, and can reduce the fuel consumption of the engine 100 and the environmental load substances contained in the exhaust gas.

  Further, as shown in FIGS. 4 and 5, the intake manifold 24 provided in the engine 100 is arranged from the wall surface 24 w to the inside of the collecting portion 241 to guide the air-fuel mixture stored in the collecting portion 241 to the communication port 24 h. A guide passage 243 is provided so as to project in the space. That is, the intake manifold 24 is provided with the guide passage 243 in the internal space of the collecting portion 241 so as to extend the branch pipe 242A. The guide passage 243 is formed such that the passage cross-sectional area of the guide passage 243 and the passage cross-sectional area of the communication port 24h are the same. For example, the guide cross-sectional area increases as the distance from the wall surface 24w increases. A so-called bell mouth shape may be used, and the present invention is not limited to this.

  As described above, the intake manifold 24 can provide the same effect as that of increasing the flow path length of the branch pipe 242A by providing the guide passage 243 for guiding the air-fuel mixture to the communication port 24h. That is, the intake manifold 24 can suppress the disturbance of the air-fuel mixture flowing inside the branch pipe 242A, and can rectify the flow of the air-fuel mixture. In this way, the intake manifold 24 can distribute the air-fuel mixture flowing into the branch pipes 242A... From the collecting portion 241 to the combustion chambers 15 of the respective cylinders without variation.

  With the above-described configuration, the intake manifold 24 evenly distributes the air-fuel mixture obtained after uniformly mixing the combustible gas and air to the combustion chambers 15 of the respective cylinders with higher accuracy. Can do. As a result, the engine 100 can suppress variations in the combustion stroke between the cylinders, and can reduce the fuel consumption of the engine 100 and the environmental load substances contained in the exhaust gas.

  4 and 5, the intake manifold 24 provided in the engine 100 has a wall surface 24w that separates the internal space of the collecting portion 241 and the internal spaces of the branch pipes 242A. It is formed so as to incline with a downward slope toward the mouth 24h. An oil passage 243 h that connects the internal space of the guide passage 243 and the internal space of the collecting portion 241 is provided on the peripheral wall surface of the guide passage 243. The oil passage 243h is a slit formed by cutting a part of the peripheral wall surface of the guide passage 243 from the upstream end of the guide passage 243 to the wall surface 24w. For example, the inner peripheral surface is formed along the wall surface 24w. However, the present invention is not limited to this.

  In this way, the intake manifold 24 is formed in such a manner that the wall surface 24w is inclined downward toward each communication port 24h, and the oil passage 243h is provided in the guide passage 243, so that it is included in the combustible gas. Oil contained in tar or blow-by gas can be guided to the combustion chamber 15 of each cylinder without being accumulated in the collecting portion 241 (see black arrows in FIG. 5). In this way, the intake manifold 24 can prevent the tar contained in the combustible gas and the oil contained in the blow-by gas from being accumulated and guided to the combustion chamber 15 of a certain cylinder.

  By adopting the above-described configuration, the intake manifold 24 prevents the tar contained in the combustible gas and the oil contained in the blow-by gas from accumulating inside the intake manifold 24. Can be prevented from being biased toward the combustion chamber 15. As a result, the engine 100 can suppress variations in the combustion stroke between the cylinders, and can reduce the fuel consumption of the engine 100 and the environmental load substances contained in the exhaust gas.

  Further, as shown in FIG. 5, in the intake manifold 24 provided in the engine 100, the intake air temperature sensor 18 is arranged at a position farthest from the communication port 24h in the collecting portion 241. Therefore, the intake manifold 24 is provided on the left side on the upper surface of the collecting portion 241 and is provided with a mounting portion 241B for the intake air temperature sensor 18 in the central portion in the front-rear direction (see FIG. 3). In the intake manifold 24, the intake air temperature sensor 18 is disposed. However, for example, a pressure sensor, an air-fuel ratio sensor, or the like may be used, but the present invention is not limited thereto.

  In this way, the intake manifold 24 reduces the influence of the pulsation caused by the operation cycle on the intake air temperature sensor 18 by disposing the intake air temperature sensor 18 at the position farthest from the communication port 24h in the collecting portion 241. be able to. That is, the intake manifold 24 can reduce the influence of the pulsation on the intake air temperature sensor 18 by attenuating the pulsation by the collecting portion 241.

  With the configuration as described above, engine 100 can prevent noise from entering the detection signal from intake air temperature sensor 18, and can improve detection accuracy.

  Next, the reason why the intake manifold 24 provided in the engine 100 can improve productivity and reduce costs will be described with reference to FIGS. 6 (A) and 6 (B).

  FIG. 6A is a schematic diagram illustrating a manufacturing process of the intake manifold 24 provided in the engine 100, and FIG. 6B is a schematic diagram illustrating a manufacturing process of another intake manifold. In addition, the arrow shown in the figure has shown the separation direction of the casting_mold | template at the time of manufacturing the intake manifold 24 and another intake manifold.

  As shown in FIG. 6B, in another intake manifold, a space 245 is provided between the collecting portion 241 and the branch pipe 242A. In such an intake manifold, the upper surface and the side surface of the collecting portion 241 are provided. The mold Mo1 that forms the upper surface of the branch pipe 242A is separated upward, the lower surface and the mold Mo2 that forms the side surfaces of the branch pipe 242A are separated downward, and the lower surface of the assembly 241 and the mold Mo3 that forms the upper surface of the branch pipe 242A It is necessary to separate in the left direction in the figure.

  That is, this intake manifold in which the space 245 is provided between the collecting portion 241 and the branch pipe 242A requires three molds Mo1, Mo2, and Mo3, and each mold Mo1, Mo2, and Mo3 is in different directions. Need to be separated.

  On the other hand, as shown in FIG. 6 (A), the intake manifold 24 provided in the engine 100 has the inner space of the collecting portion 241 and the inner space of the branch pipe 242A separated by a wall surface 24w. The mold Mn1 forming the upper surface and the side surface of the portion 241 can be separated upward, and the mold Mn2 forming the lower surface and the side surface of the branch pipe portion 242 can be separated downward.

  In other words, the intake manifold 24 in which the inner space of the collecting portion 241 and the inner space of the branch pipe 242A are separated by the wall surface 24w can be manufactured with two molds Mn1 and Mn2, and further, the molds Mn1 and Mn2 are vertically moved. It can be manufactured by separating into two.

  As described above, the intake manifold 24 provided in the engine 100 can reduce the number of molds required at the time of manufacturing the intake manifold 24, and the separation of the respective molds is simple. This makes it possible to reduce costs.

DESCRIPTION OF SYMBOLS 100 Engine 1 Engine main part 2 Intake passage part 3 Exhaust passage part 15 Combustion chamber 18 Intake temperature sensor 24 Intake manifold 24h Communication port 24w Wall surface 241 Collecting part 242 Branch pipe part 242A Branch pipe 243 Guide passage 243h Oil passage

Claims (3)

An engine having an intake manifold fixed to a cylinder head and guiding an air-fuel mixture to a combustion chamber,
The intake manifold is composed of a collecting part for storing an air-fuel mixture, and a branch pipe part for distributing the air-fuel mixture stored in the collecting part to the combustion chamber,
The assembly portion and the branch pipe portion are configured to be integrally formed with a mold,
The internal space of the assembly part is separated from the internal space of each branch pipe constituting the branch pipe part by a wall surface,
A communication port that communicates the internal space of the collecting portion and the internal space of the branch pipe at a position where the flow path length of the branch pipe of the wall surface is the longest,
In order to guide the air-fuel mixture stored in the collecting portion to the communication port, a guide passage projecting from the communication port of the wall surface to the inner space side of the collecting portion is provided,
An engine characterized in that an oil passage is provided in a peripheral wall surface at a position of the wall surface of the guide passage so as to allow the internal space of the guide passage and the internal space of the collective portion to communicate with each other. 2. The engine according to claim 1, wherein a wall surface that separates the internal space of the collecting portion and the internal space of the branch pipe is formed so as to be inclined downward toward the communication port. . 3. The engine according to claim 1, wherein the intake manifold has an intake air temperature sensor disposed at a position farthest from the communication port in the collective portion .

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