JP2021173226A - Intake device of engine - Google Patents

Abstract

To provide an intake device of an engine, which enables a decrease in a flow volume of EGR gas to be prevented, and enables the vibration of an EGR valve to be suppressed even if the EGR valve is arranged in a position of an end part of a cylinder head in a cylinder row direction so that an upper end of the EGR valve is located above an upper end of the cylinder head.SOLUTION: EGR piping 40 has: an upstream-side pipe portion 41 connected to an exhaust gas outlet 14A; a downstream-side pipe portion 42 arranged while being deviated (offset) to the upstream-side pipe portion 41 in a cylinder row direction, and connected to an exhaust gas inlet 38; and a middle pipe portion 43 connecting the upstream-side pipe portion 41 and the downstream-side pipe portion 42. The EGR piping 40 is formed while being curved in a crank shape along a peripheral side of a throttle device 7 so that the middle pipe portion 43 communicates with the upstream-side pipe portion 41 and the downstream-side pipe portion 42 while being orthogonal thereto. Then, an area of the passage cross section of the middle pipe portion 43 is set to be larger than the area of the passage cross section of the upstream-side pipe portion 41 and the area of the passage cross section of the downstream-side pipe portion 42.SELECTED DRAWING: Figure 2

Description

The present invention relates to an engine intake device.

As an intake device for a conventional engine, the one described in Patent Document 1 is known. The engine intake device described in Patent Document 1 is an exhaust gas recirculation device having an EGR gas recirculation passage for recirculating exhaust gas from an exhaust pipe to an intake manifold and an EGR valve (EGR control valve) for adjusting the flow rate of EGR gas. It has. The EGR valve of this exhaust gas recirculation device is attached to a housing connected to the end of the cylinder head.

Japanese Unexamined Patent Publication No. 2000-87807

Here, in order to avoid an increase in the intake air temperature of the engine and a decrease in the engine output due to the introduction of the EGR gas, it is desirable to provide an EGR cooler in the EGR recirculation device to cool the EGR. When the EGR cooler is provided in the EGR recirculation device, it is desirable to arrange the EGR valve at a high position and install the EGR cooler below the EGR valve. This is because the size of the EGR cooler and the degree of freedom in the installation posture can be increased, and the cooling performance of the EGR gas can be ensured.

However, in the intake system of a conventional engine, when the EGR valve is installed at a high position so that the upper end thereof is located above the upper end of the cylinder head for the installation of the EGR cooler, the EGR valve is used. Since it is supported only around the lower end, the vibration of the EGR valve may increase.

Further, when the throttle device connected to the intake manifold is arranged adjacent to the EGR valve in a posture in which the intake flow direction faces upward, the EGR pipe connecting the EGR valve and the intake manifold avoids interference with the throttle device. Therefore, since it is necessary to bend the EGR gas in a complicated manner, there is a possibility that the flow rate of the EGR gas may decrease due to an increase in pressure loss in the EGR piping.

The present invention has been made by paying attention to the above circumstances, and the EGR valve is placed at the end of the cylinder head in the cylinder row direction so that the upper end of the EGR valve is located above the upper end of the cylinder head. It is an object of the present invention to provide an engine intake device capable of preventing a decrease in the flow rate of the EGR gas and suppressing vibration of the EGR valve even when the EGR gas is arranged at the position of the portion.

The present invention comprises an intake manifold having a surge tank extending in the cylinder row direction, a plurality of intake pipes branched from the surge tank and connected to a cylinder head in a state of being arranged in the cylinder row direction, and the surge tank. A throttle device attached to the upper surface of one end in the cylinder row direction, an EGR valve attached to one end of the cylinder head in the cylinder row direction, and a side surface of the EGR valve on the intake manifold side. An exhaust gas outlet provided above the upper end of the cylinder head, an exhaust gas inlet provided on the upper surface of the intake manifold, and an EGR pipe connecting the exhaust gas outlet and the exhaust gas inlet are provided. In the intake device of the engine, the EGR pipe is arranged so as to be offset in the cylinder row direction with respect to the upstream side pipe portion connected to the exhaust gas outlet and the upstream side pipe portion, and the exhaust gas inlet. It has a downstream side pipe portion connected to, and an intermediate pipe portion that connects the upstream side pipe portion and the downstream side pipe portion, and the intermediate pipe portion is the upstream side pipe portion and the downstream side pipe portion. It is formed by bending in a crank shape along the periphery of the throttle device so as to be connected orthogonally to and, and the area of the passage cross section of the intermediate pipe portion is the upstream side pipe portion and the downstream side. It is characterized in that it is larger than the passage cross section of the pipe portion.

As described above, according to the present invention, the EGR valve is arranged at the position of the end portion of the cylinder head in the cylinder row direction so that the upper end of the EGR valve is located above the upper end of the cylinder head. Even if there is, it is possible to provide an engine intake device capable of preventing a decrease in the flow rate of the EGR gas and suppressing vibration of the EGR valve.

FIG. 1 is a left side view of an engine including an intake device according to an embodiment of the present invention. FIG. 2 is a plan view of an engine including an intake device according to an embodiment of the present invention. FIG. 3 is a rear view of an engine including an intake device according to an embodiment of the present invention. FIG. 4 is a cross-sectional view taken along the line in the IV-IV direction of the engine shown in FIG. FIG. 5 is a cross-sectional view taken along the line VV of the engine shown in FIG.

The intake device of the engine according to the embodiment of the present invention includes a surge tank extending in the cylinder row direction, a plurality of intake pipes branched from the surge tank and connected to the cylinder head in a state of being arranged in the cylinder row direction. The intake manifold, the throttle device attached to the upper surface of one end of the surge tank in the cylinder row direction, the EGR valve attached to one end of the cylinder head in the cylinder row direction, and the side surface of the EGR valve on the intake manifold side. An engine including an exhaust gas outlet provided above the upper end of the cylinder head, an exhaust gas inlet provided on the upper surface of the intake manifold, and an EGR pipe connecting the exhaust gas outlet and the exhaust gas inlet. The EGR pipe is the intake device of the above, and the upstream side pipe portion connected to the exhaust gas outlet and the downstream side connected to the exhaust gas inlet are arranged unevenly in the cylinder row direction with respect to the upstream side pipe portion. It has a pipe portion and an intermediate pipe portion that connects the upstream side pipe portion and the downstream side pipe portion so that the intermediate pipe portion is connected orthogonally to the upstream side pipe portion and the downstream side pipe portion. It is formed by bending in a crank shape along the periphery of the throttle device, and the area of the passage cross section of the intermediate pipe portion is larger than the passage cross section of the upstream side pipe portion and the downstream side pipe portion. Thereby, in the intake device of the engine according to the embodiment of the present invention, the EGR valve is set at the end of the cylinder head in the cylinder row direction so that the upper end of the EGR valve is located above the upper end of the cylinder head. Even when it is arranged at the position of, it is possible to prevent a decrease in the flow rate of the EGR gas and suppress the vibration of the EGR valve.

Hereinafter, the intake device of the engine according to an embodiment of the present invention will be described with reference to the drawings. 1 to 5 are views showing an intake device of an engine according to an embodiment of the present invention. In FIGS. 1 to 5, the up / down / front / rear / left / right directions are the up / down / front / rear / left / right directions of the engine installed horizontally in the vehicle, the direction orthogonal to the front / rear direction is the left / right direction, and the height direction of the engine is up / down. The direction.

First, the configuration will be described. In FIG. 1, the engine 1 includes an engine body 1A. The engine body 1A includes a cylinder block 3, a cylinder head 2 connected to the upper part of the cylinder block 3, a head cover 4 provided on the upper part of the cylinder head 2, and an oil pan 5 connected to the lower part of the cylinder block 3. It has. Further, the engine body 1 is provided with a chain cover 8 (see FIG. 3) that covers a timing chain (not shown) at the right ends of the cylinder block 3 and the cylinder head 2.

The cylinder block 3 is formed with a plurality (three) cylinders (not shown) for accommodating pistons (not shown) so as to be vertically movable. The cylinder block 3 houses a crank shaft 11 that converts the vertical movement of the piston into a rotational movement, and the crank shaft 11 extends in the left-right direction. The plurality of cylinders are arranged side by side in the left-right direction (hereinafter, also referred to as the cylinder row direction) in which the crank shaft 11 extends.

A plurality of combustion chambers (not shown) are provided on the bottom of the cylinder head 2. The combustion chamber is provided at the top of each cylinder. In this embodiment, the cylinder head 2 is provided with three combustion chambers arranged in a row in the left-right direction. An exhaust outlet not shown in the drawing is provided at the front portion of the cylinder head 2, and the exhaust outlet discharges exhaust gas.

In FIG. 1, the engine 1 includes an intake manifold 20. The intake manifold 20 is attached to the rear side surface of the cylinder head 2, and distributes air that has passed through an air cleaner (not shown) to a plurality of (three in this embodiment) intake ports (not shown) of the cylinder head 2. The engine 1 ignites and burns an air-fuel mixture composed of air and fuel taken in from an intake port by an ignition plug (not shown), and exhausts exhaust gas after combustion from an exhaust outlet.

The intake manifold 20 includes a surge tank 21 that temporarily stores air, and a wide range portion 22 that distributes air from the surge tank 21 to each intake port of the cylinder head 2. The surge tank 21 extends in the cylinder row direction. The multi-purpose portion 22 is composed of three intake pipes 23, 24, and 25.

The intake pipes 23, 24, and 25 branch from the surge tank 21 and are connected to the cylinder head 2 in a state of being arranged in the cylinder row direction. A throttle device 7 for controlling the flow rate of air is attached to the upper surface of one end (left end) of the surge tank 21 in the cylinder row direction. The throttle device 7 supplies the filtered air to the intake manifold 20 through an air cleaner (not shown).

An exhaust pipe 10 through which exhaust gas passes is provided in front of the engine body 1A. In FIG. 1, the exhaust pipe 10 is composed of a catalyst device for purifying exhaust gas.

EGR pipes 12A and 12B and an EGR cooler 13 are provided on the left side of the engine body 1A to return a part of the exhaust gas passing through the exhaust pipe 10 to the intake path. The EGR cooler 13 is provided between the EGR pipes 12A and the EGR pipes 12A and 12B, and cools the exhaust gas by heat exchange with the cooling water.

An EGR valve 14 is provided at the downstream end of the EGR pipe 12B, and the EGR valve controls the flow rate of the exhaust gas. The EGR valve 14 is attached to one end (left end) of the cylinder head 2 in the cylinder row direction. In other words, the EGR valve 14 is attached to the end of the cylinder head 2 on the throttle device 7 side in the cylinder row direction. Therefore, the EGR valve 14 is adjacent to the throttle device 7.

A part of the exhaust gas passing through the exhaust pipe 10 is returned to the intake path after passing through the EGR pipe 12A, the EGR cooler 13, the EGR pipe 12B and the EGR valve 14.

The EGR valve 14 is provided with an exhaust gas outlet 14A. The exhaust gas outlet 14A is a side surface of the EGR valve 14 on the intake manifold 20 side, and is provided above the upper end of the cylinder head 2.

The EGR valve 14 is provided with an exhaust gas outlet 14A. The exhaust gas outlet 14A is a side surface of the EGR valve 14 on the intake manifold 20 side, and is provided above the upper end of the cylinder head 2. Therefore, the EGR valve 14 is arranged at a high position where the upper end thereof is located above the upper end of the cylinder head 2.

The engine 1 includes an EGR pipe 40, and connects the exhaust gas outlet 14A of the EGR valve 14 and the exhaust gas inlet 38 of the additive gas supply pipe 30 described later.

In FIGS. 2 and 3, an additional gas supply pipe 30 is provided in the intake manifold 20, and the additional gas supply pipe 30 introduces an additional gas (exhaust gas) into the air flowing in the intake pipes 23, 24, and 25. do. The additive gas supply pipe 30 is provided on the upper surface of the intake manifold 20, and distributes and supplies the additive gas introduced from the exhaust pipe 10 to the intake pipes 23, 24, and 25 of the intake manifold 20.

In FIGS. 2 and 3, the additive gas supply pipe 30 is formed by joining the upper and lower members. The additive gas supply pipe 30 first bifurcates into a path to the intake pipe 23 and another path, and then the other path bifurcates into a path to the intake pipe 24 and a path to the intake pipe 25. It has a structure. As described above, the added gas supply pipe 30 has a structure similar to the tournament table.

Specifically, the additive gas supply pipe 30 is provided from the exhaust gas inlet 38 that takes in the exhaust gas as the additive gas, the first pipe portion 31 that extends from the exhaust gas inlet 38 in the cylinder row direction, and the downstream end of the first pipe portion 31. A second pipe portion 32 extending in an intersecting direction intersecting the cylinder row direction, and a first branch pipe portion 34 and a second branch pipe portion 35 extending from the downstream end of the second pipe portion 32 to opposite sides in the cylinder row direction. have.

A boss-shaped flange portion 38A is provided around the exhaust gas inlet 38, and a pipe (not shown) for supplying added gas is connected to the flange portion 38A. Since the additive gas supply pipe 30 is arranged on the upper surface of the intake manifold 20, the exhaust gas inlet 38 is arranged on the upper surface of the intake manifold 20.

The additive gas supply pipe 30 includes a third pipe portion 33 connected to the downstream end of the second branch pipe portion 35, and a third branch pipe portion 36 and a fourth branch pipe portion 36 extending from the downstream end of the third pipe portion 33 to opposite sides. It has a branch pipe portion 37.

At the downstream end of the first branch pipe portion 34, a first communication port 34A that communicates with the intake pipe 23 is provided. At the downstream end of the third branch pipe portion 36, a second communication port 36A that communicates with the intake pipe 24 is provided. At the downstream end of the fourth branch pipe portion 37, a third communication port 37A that communicates with the intake pipe 25 is provided.

In FIG. 2, the EGR pipe 40 is arranged so as to be offset in the cylinder row direction with respect to the upstream pipe portion 41 connected to the exhaust gas outlet 14A and the upstream pipe portion 41, and is arranged at the exhaust gas inlet 38. It has a downstream side pipe portion 42 to be connected, and an intermediate pipe portion 43 connecting the upstream side pipe portion 41 and the downstream side pipe portion 42. The EGR pipe 40 extends from the upper side to the lower side so as to be lower toward the downstream side as a whole.

The EGR pipe 40 is formed by bending in a crank shape along the periphery of the throttle device 7 so that the intermediate pipe portion 43 is connected orthogonally to the upstream pipe portion 41 and the downstream pipe portion 42. .. The area of the passage cross section of the intermediate pipe portion 43 is larger than the passage cross section of the upstream side pipe portion 41 and the downstream side pipe portion 42.

In FIGS. 2 and 5, the intermediate pipe portion 43 includes a first member 43A and a second member 43B joined by a joining surface 43C extending in the vertical direction. The upstream side pipe portion 41 is connected to the first member 43A, and the downstream side pipe portion 42 is connected to the second member 43B.

In other words, the intermediate pipe portion 43 is divided into a first member 43A and a second member 43B with the joint surface 43C extending in the vertical direction as a dividing surface, and the first member 43A and the second member 43B It consists of a combination of. That is, the EGR pipe 40 is not formed by bending a straight pipe having a constant cross-sectional area, but is a member constituting the upstream side pipe portion 41 and the first member 43A, and the downstream side pipe portion 42 and the second member. It is composed of a member formed of 43B and joined by a joining surface 43C. The EGR pipe 40 can be manufactured by a method such as die casting.

In FIGS. 4 and 5, the passage inside the intermediate pipe portion 43 is formed in a cross-sectional shape in which the size in the height direction (extension direction of the joint surface 43C) is larger than the size in the width direction (orthogonal direction of the joint surface 43C). Has been done. That is, the passage inside the intermediate pipe portion 43 is formed in a vertically long shape.

As described above, in the present embodiment, the EGR pipe 40 is arranged so as to be offset in the cylinder row direction with respect to the upstream pipe portion 41 connected to the exhaust gas outlet 14A and the upstream pipe portion 41. It has a downstream side pipe portion 42 connected to the exhaust gas inlet 38, and an intermediate pipe portion 43 connecting the upstream side pipe portion 41 and the downstream side pipe portion 42.

Further, the EGR pipe 40 is formed by bending in a crank shape along the periphery of the throttle device 7 so that the intermediate pipe portion 43 is connected orthogonally to the upstream side pipe portion 41 and the downstream side pipe portion 42. ing. The area of the passage cross section of the intermediate pipe portion 43 is larger than the passage cross section of the upstream side pipe portion 41 and the downstream side pipe portion 42.

As a result, the area of the passage cross section of the intermediate pipe portion 43 is made larger than that of the upstream side pipe portion 41 and the downstream side pipe portion 42, so that the rigidity of the intermediate pipe portion 43 in which the external force from the EGR valve 14 is concentrated can be improved. The rigidity of the EGR pipe 40 against bending and twisting can be improved. Further, by increasing the area of the passage cross section of the intermediate pipe portion 43, the flow rate of the EGR gas can be secured even when the EGR pipe 40 is bent.

As a result, even when the EGR valve 14 is arranged at the position of the end portion of the cylinder head 2 in the cylinder row direction so that the upper end of the EGR valve 14 is located above the upper end of the cylinder head 2. It is possible to prevent a decrease in the flow rate of the EGR gas and suppress the vibration of the EGR valve 14.

Further, in this embodiment, the intermediate pipe portion 43 includes a first member 43A and a second member 43B joined by a joining surface 43C extending in the vertical direction. Further, the upstream side pipe portion 41 is connected to the first member 43A, and the downstream side pipe portion 42 is connected to the second member 43B.

As a result, the intermediate pipe portion 43 is formed by joining the first member and the second member, so that the intermediate pipe portion 43 can be easily designed and manufactured in an internal passage shape and a cross-sectional area to obtain a desired rigidity. , The rigidity of the EGR pipe 40 can be further improved, and the vibration of the EGR valve 14 can be suppressed.

Further, in the present embodiment, the passage inside the intermediate pipe portion 43 is formed in a cross-sectional shape in which the size in the height direction (extension direction of the joint surface 43C) is larger than the size in the width direction (orthogonal direction of the joint surface 43C). Has been done.

Thereby, the rigidity of the portion continuous from the upstream side pipe portion 41 to the intermediate pipe portion 43 and the rigidity of the portion continuous from the intermediate pipe portion 43 to the downstream side pipe portion 42 can be ensured.

Further, when the EGR pipe 40 is formed in a shape extending from the upper side to the lower side as in the present embodiment, the EGR pipe 40 can be bent in the vertical direction more gently than in the orthogonal direction (horizontal direction), and is a straight pipe. The pressure loss can be reduced as compared with the case of bending.

In addition to this, it is possible to suppress twisting of the intermediate pipe portion 43 in the vertical direction with respect to the vibration direction of the EGR valve 14. Therefore, the vibration of the EGR valve 14 can be further suppressed.

Although the embodiments of the present invention have been disclosed, it is clear that some skilled in the art can make changes 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, 1A ... engine body, 2 ... cylinder head, 7 ... throttle device, 14 ... EGR valve, 14A ... exhaust gas outlet, 20 ... intake manifold, 21 ... surge tank, 23, 24, 25 ... intake pipe, 38 ... exhaust gas inlet, 40 ... EGR pipe, 41 ... upstream pipe, 42 ... downstream pipe, 43 ... Intermediate pipe part, 43A ... 1st member, 43B ... 2nd member, 43C ... Joint surface

Claims (3)

An intake manifold having a surge tank extending in the cylinder row direction and a plurality of intake pipes branched from the surge tank and connected to a cylinder head in a state of being arranged in the cylinder row direction.
A throttle device attached to the upper surface of one end of the surge tank in the cylinder row direction,
An EGR valve attached to one end of the cylinder head in the cylinder row direction,
An exhaust gas outlet provided on the side surface of the EGR valve on the intake manifold side and above the upper end of the cylinder head.
An exhaust gas inlet provided on the upper surface of the intake manifold and
An intake device for an engine including an EGR pipe connecting the exhaust gas outlet and the exhaust gas inlet.
The EGR pipe
The upstream pipe section connected to the exhaust gas outlet and
A downstream pipe portion that is arranged unevenly in the cylinder row direction with respect to the upstream pipe portion and is connected to the exhaust gas inlet.
It has an intermediate pipe portion that connects the upstream side pipe portion and the downstream side pipe portion, and has.
The intermediate pipe portion is formed by bending in a crank shape along the periphery of the throttle device so that the upstream side pipe portion and the downstream side pipe portion are connected orthogonally to each other.
An engine intake device characterized in that the area of the passage cross section of the intermediate pipe portion is larger than the passage cross section of the upstream side pipe portion and the downstream side pipe portion. The intermediate pipe portion is composed of a first member and a second member joined by a joining surface extending in the vertical direction.
The intake device for an engine according to claim 1, wherein the upstream side pipe portion is connected to the first member, and the downstream side pipe portion is connected to the second member. The intake device for an engine according to claim 1 or 2, wherein the passage inside the intermediate pipe portion is formed in a cross-sectional shape in which the size in the height direction is larger than the size in the width direction.

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