JP2004245114A - Intake manifold of v-type engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress reduction in volumetric efficiency by temperature rising of a wall surface of an intake manifold in an V-type engine and to increase output of the engine. <P>SOLUTION: The intake manifold 1 of the V-type engine has intake branch parts 11 and 12 that are disposed in a space 16 between banks of the V-type engine and guide respective intake airs to respective cylinders of both banks. A crosslinking section 15 for separating an upper space 16a of the space 16 from a lower space 16b is formed in the intake branch parts 11 and 12, and the crosslinking section 15 is provided with gas passages 17 and 19, and 18 and 20 that open in the intake branch parts 11 and 12 and supply secondary added gas. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an intake manifold for a V-type engine, and more particularly, to an intake manifold having an additional gas passage for adding a secondary additive gas such as EGR gas, blow-by gas, and canister purge to intake air and supplying the gas to each cylinder.
[0002]
[Prior art]
2. Description of the Related Art In a vehicle engine, a device for adding a secondary additive gas such as an EGR gas, a blow-by gas, and a canister purge to air taken in from a throttle valve is mainly provided. In order to prevent uneven distribution of cylinders of secondary additive gas, sticking and sticking of the throttle valve, etc., a gas passage is connected to each intake branch of the intake manifold and secondary additive gas is supplied to each cylinder. It is desirable.
[0003]
Patent Document 1 discloses that a thick portion is provided inside an intake branch portion of each bank in an intake manifold of a V-type engine to supply EGR gas to each cylinder, and a gas passage is provided in each thick portion. Are formed, and each gas passage is connected to an intake passage of each branch portion.
Further, in Patent Document 2, in the intake manifold of a V-type engine, a crotch portion of an intake branch portion is formed thick to form one gas passage in the thick portion, and this gas passage is connected to each intake branch portion. Is shown in FIG. In this intake manifold, only one gas passage is formed, and EGR gas or blow-by gas is supplied from this gas passage to the intake passage of each branch.
[0004]
[Patent Document 1]
JP-A-6-81721 (page 3-4, FIG. 1-2)
[0005]
[Patent Document 2]
Japanese Patent Application Laid-Open No. Hei 10-122071 (page 3-4, FIG. 3-4)
[0006]
[Problems to be solved by the invention]
In the intake manifold described in Patent Literature 1, since the intake manifold is disposed in the space between banks of the V-type engine, the temperature of the wall surface of the intake manifold tends to increase due to heat radiation from the engine. When the wall temperature of the intake manifold rises, the temperature of the intake air flowing through the intake branch of the intake manifold rises, and the volumetric efficiency drops, leading to a decrease in engine output.
[0007]
Further, in this intake manifold, since the gas passage is close to the branch portion and the contact area between the thick portion and the branch portion is large, the heat of the EGR gas is easily transmitted to the wall surface of the intake branch portion. Therefore, when the intake branch portion is heated by the heat, the temperature of the intake air flowing through the intake passage increases, the volume efficiency decreases, and the engine output decreases.
[0008]
Also, in the intake manifold described in Patent Document 2, similarly to the above, the wall temperature of the intake manifold easily rises due to heat radiation from the engine, and the temperature of the intake air flowing through the intake branch portion of the intake manifold rises, thereby increasing the volumetric efficiency. And the engine output is reduced.
In addition, since the intake passages of both banks are connected to each other via the gas passage, in the resonance variable intake system in which the collector is divided and the output is improved by utilizing the pulsation amplitude in each collector, the pulsation in each collector is Cancel each other and impair the effect of improving the output.
[0009]
An object of the present invention is to improve the output of the V-type engine by suppressing a decrease in volumetric efficiency due to a rise in the temperature of the wall surface of the intake manifold.
Another object of the present invention is to improve the durability of an intake manifold in a V-type engine.
Another object of the present invention is to prevent the pulsations in the respective collectors from canceling each other when the resonance variable intake system is used in a V-type engine, improve the effect of variable intake, and improve the engine output. .
[0010]
[Means for Solving the Problems]
An intake manifold of a V-type engine according to the present invention includes an intake branch portion provided in an inter-bank space of the V-type engine and guiding intake air to each cylinder of both banks. A bridging portion that is separated from the lower space is formed, and a gas passage that opens to the intake branch portion and supplies the secondary additive gas is formed in the bridging portion.
[0011]
It is preferable that a thin brittle portion is formed in the bridge portion. Further, the gas passage may be divided into a first passage for supplying the secondary additive gas to the cylinder of one bank and a second passage for supplying the secondary additive gas to the cylinder of the other bank. preferable.
[0012]
【The invention's effect】
According to the present invention, since the heat radiation from the engine is blocked by the bridge portion, the heating of the intake manifold can be suppressed. As a result, it is possible to prevent the volume efficiency from deteriorating due to the heating of the air flowing through the intake branch portion of the intake manifold, and prevent the output of the engine from decreasing.
[0013]
In the present invention, when a thin brittle portion is formed in the bridge portion, the provision of the bridge portion can prevent the rigidity of the entire intake manifold from becoming too high, and can easily absorb vibration between the banks. As a result, the durability of the intake manifold can be improved.
Further, in the present invention, when the gas passage is divided into the first and second gas passages and each gas passage is connected to the intake passage of each bank, the gas passage does not connect between the banks. In the system, the pulsation in each collector can be prevented from canceling each other, and the output of the engine can be further improved.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
(1) First Embodiment (1-1) Configuration FIG. 1 is a cross-sectional view of an intake system to which an intake manifold according to the present invention is applied. FIG. 2 is an enlarged view of the intake manifold. FIG. 3 is a plan view showing the arrangement of the first and second gas passages formed in the intake manifold and each cylinder of the V-type six-cylinder engine.
[0015]
The intake manifold 1 constituting this intake system is generally constituted by an intake branch portion and a collector portion disposed upstream thereof. An engine body 2 to which intake air is supplied from the intake manifold 1 is connected to a downstream side of the intake manifold 1.
The engine body 2 has first to sixth cylinders 91 to 96 as shown in FIG. The first to sixth cylinders 91 to 96 have two intake ports 71, 81 to 76 and 86, respectively, and one intake port 81 to 86 of each cylinder is provided with an intake control valve 61 to 66, respectively. Is provided. The first cylinder 91, the third cylinder 93, and the fifth cylinder 95 constitute a right engine bank (first cylinder group), and the second cylinder 92, the fourth cylinder 94, and the sixth cylinder 96 constitute a left engine bank (second cylinder). Group). As shown in FIG. 3, the intake ports 71, 73, 75 are respectively connected to a first gas passage portion 17 described later by a communication passage 19, and the intake ports 72, 74, 76 are connected to a second gas passage portion 18 described later. The intake ports 81 to 86 provided with the intake control valves 61 to 66 are connected to both the first gas passage portion 17 and the second gas passage portion 18, although they are connected to each other by the two communication passages 20. Absent.
[0016]
The engine body 2 includes a first cylinder bank 5 and a second cylinder bank 6 arranged in a substantially V-shape as shown in FIG. 1, and a first cylinder head 3 is provided above the first cylinder bank 5. The second cylinder head 4 is mounted above the second cylinder bank 6. A cylinder constituting the first cylinder 91 is formed in the first cylinder bank 5, and a piston is disposed in the cylinder. The combustion is caused by the inner wall of the cylinder, the upper surface of the piston, and the inner wall of the first cylinder head 3. Form a chamber. The first cylinder head 3 is formed with two intake ports 71 and 81 corresponding to the first cylinder 91. A cylinder constituting the second cylinder 92 is similarly formed in the second cylinder bank 6, and a piston is disposed in this cylinder. The inner wall of the second cylinder bank 6, the upper surface of the piston, and the second cylinder head 4 A combustion chamber is formed with the inner wall of the cylinder. The second cylinder head 4 has two intake ports 72 and 82 corresponding to the second cylinder 92. Here, the first cylinder 91 and the second cylinder 92 will be described as an example, but the first cylinder bank 5 and the third cylinder 93 and the fifth cylinder 95 formed on the first cylinder head 3 and the second cylinder bank 6 The fourth cylinder 94 and the sixth cylinder 96 formed in the second cylinder head 4 have the same configuration.
[0017]
The intake manifold 1 is disposed in a space 16 between banks arranged in a substantially V-shape, and the intake branch portion thereof includes a first branch portion 11 and a second branch portion 12 arranged in a substantially inverted V-shape. And a bridging portion 15. The first branch portion 11 has a downstream side connected to the intake port of each cylinder of the first cylinder group, and the second branch portion has a downstream side connected to the intake port of each cylinder of the second cylinder group. , The upstream side is connected to the collector 100. Describing the first cylinder 91 as a representative, the first branch portion 11 has a first intake passage 13 for circulating intake air therein. The downstream side of the first intake passage 13 communicates with the combustion chamber via the intake port 71 of the first cylinder 91, and the upstream side communicates with a first passage 103 of the collector 100, which will be described later. The supplied intake air is supplied to the combustion chamber via the intake port 71 of the first cylinder 91. Next, the second cylinder 92 will be described as a representative example. The second branch portion 12 has a second intake passage 14 through which intake air flows. The downstream side of the second intake passage 14 communicates with the combustion chamber via the intake port 72 of the second cylinder 92, and the upstream side communicates with a second passage 104 of the collector 100 described later. The supplied intake air is supplied to the combustion chamber via the intake port 72 of the second cylinder 92. The first branch portion 11 and the second branch portion 12 have first and second fuel injection devices (not shown) provided on outer walls 11a and 12a on the downstream side, respectively. Then, fuel is injected into the first intake passage 13 and the second intake passage 14.
[0018]
The bridging portion 15 has a bridging main body 15a, and first and second connecting portions 15b and 15c formed at both ends of the bridging main body 15a. The first connecting portion 15b and the second connecting portion 15c are fragile portions formed to be thinner than the bridge main body 15a, and are connected to the opposing outer walls 11b and 12b of the first branch portion 11 and the second branch portion 12, respectively. Have been. The bridge portion 15 is formed continuously over substantially the entire length of the engine in the front-rear direction (crankshaft direction), and blocks the space 16 between the upper space 16a and the lower space 16b. The upper space 16a functions as an air passage 16a as described later in detail, and the first branch portion 11, the second branch portion 12, and the bridge portion 15 are cooled by the air flowing through the air passage 16a.
[0019]
Further, a gas passage is formed inside the bridge portion 15 along the crankshaft direction, and the gas passage is divided into a first gas passage portion 17 and a second gas passage portion 18 by a partition wall 15d. The first gas passage portion 17 and the second gas passage portion 18 are holes for passing the EGR gas, and are arranged substantially parallel to each other between the left and right engine banks as shown in FIG. Here, the cross sections of the first gas passage portion 17 and the second gas passage portion 18 are substantially rectangular, but may be other shapes such as a circle and an ellipse. The first gas passage portion 17 communicates with the first intake passage 13 via the first communication passage 19, and an opening of the first communication passage 19 on the first intake passage 13 side is provided with the EGR gas. Is supplied to the first additional gas outlet 19a. Further, the second gas passage portion 18 communicates with the second intake passage 14 via the second communication passage 20, and an opening of the second communication passage 20 on the side of the second intake passage 14 is connected to the second intake passage 14. The second additional gas outlet 20a for supplying the EGR gas is provided. Here, the first cylinder 91 and the second cylinder 92 are described as representatives, but the communication passages and the additional gas outlets are similarly formed for the other cylinders.
[0020]
In addition, the intake manifold 1 is provided with an additional gas valve 30 at the mounting portion 22 on the rear side as shown in FIG. The additive gas valve 30 has a valve body 31 and a mounting part 32, and the mounting part 32 is formed with a discharge hole 33 for discharging EGR gas. The valve body 31 controls the exhaust gas supplied from the EGR device (not shown) to the first gas passage 17 and the second gas passage 18 via the exhaust hole 33. FIG. 4 is an explanatory diagram illustrating the positional relationship between the discharge hole 33 of the additive gas valve 30 and the first gas passage 17 and the second gas passage 18. As shown in FIGS. 3 and 4, the additional gas valve 30 is fixed by two bolts 34 with the mounting portion 32 overlapping the mounting portion 22. As shown in FIG. 4, the first gas passage 17 and the second gas passage 17 are supplied so that the EGR gas can be supplied from the discharge hole 33 of the additive gas valve 30 to both the first gas passage 17 and the second gas passage 18. The portions 18 are arranged close so that the discharge holes 33 overlap when viewed from the front side. Portions of the first gas passage portion 17 and the second gas passage portion 18 that do not overlap with the discharge holes 33 are shielded by the surface of the mounting portion 32, and the first gas passage portion 17 and the second gas passage portions 18 of the discharge holes 33 Non-overlapping portions are shielded by the surface of the mounting portion 22, and the additional gas valve 30 is mounted on the intake manifold 1 so that EGR gas does not leak.
[0021]
In the intake manifold 1, a branch portion connected to the first cylinder 91 to the sixth cylinder 96 and the bridge portion 15 are integrally formed by an aluminum die casting method, and a first gas passage portion and a second gas passage portion are formed. 18 can also be formed at the same time using a core, and can be formed by closing an opening on the front side where the additive gas valve 30 is not attached.
The collector 100 includes a first chamber 101, a second chamber 102, and a third chamber 107, a first passage 103 and a second passage 104, and a first valve 105 and a second valve 106. This is a variable resonance intake system in which the suction efficiency is improved by utilizing the pulsating vibration in the first and second chambers 102 and 102. The first chamber 101, the second chamber 102, and the third chamber 107 are separated by a first valve 105 and a second valve 106, and introduce intake air taken in from a throttle valve. The first chamber 101 is electrically connected to the third chamber 107 by opening and closing the first valve 105. The upstream side of the first passage 103 communicates below the first chamber 101, and the downstream side communicates with the upstream side of the first intake passage 13. The second chamber 102 is electrically connected to the third chamber 107 by opening and closing the second valve 106. The upstream side of the second passage 104 communicates with the lower side of the second chamber 102, and the downstream side communicates with the upstream side of the second intake passage 14.
[0022]
FIG. 5 is a plan view of the front chain cover 40, and FIG. 6 is an explanatory diagram illustrating a positional relationship between the front chain cover 40 and the intake manifold 1. The front chain cover 40 is attached so as to cover the front end of the engine body 2 of the V-type six-cylinder engine and the front end of the space 16, and has a ventilation hole 41 at a position facing the upper space 16 a of the space 16. . When the front chain cover 40 is mounted on the front side of the engine, as shown in FIG. 6, the air hole 41 overlaps the air passage 16a, and air is introduced into the air passage 16a through the air hole 41, and the first branch portion is formed. 11, the second branch portion 12 and the bridge portion 15 are cooled.
[0023]
Next, an intake operation by the intake system will be described. In this intake system, the air sucked from the throttle valve is introduced into the first chamber 101 and the second chamber 102, is sent from the first chamber 101 to the first intake passage 13 via the first passage 103, The air is sent from the chamber 102 to the second intake passage 14 via the second passage 104. The first valve 105 and the second valve 106 are opened and closed according to the operation state so as to increase the suction efficiency of the cylinder. When the first and second valves 105 and 106 are closed, the first chamber 101 and the second chamber 106 are opened. When the first and second valves 105 and 106 are opened, the first chamber 101, the second chamber 102, and the third chamber 103 function as one large-capacity collector. The intake air sent to the first intake passage 13 is mixed with the EGR gas from the additive gas outlet 19 a and the fuel from the first fuel injection device to form an air-fuel mixture, and this air-fuel mixture is supplied to the first cylinder 91. While being supplied, the intake air sent to the second intake passage 14 is mixed with the EGR gas from the additive gas outlet 20a and the fuel from the second fuel injection device to form an air-fuel mixture. It is supplied to the cylinder 92.
[0024]
(1-2) Operational Effect FIG. 7 is an explanatory diagram for explaining the effect of heat release from the engine on the temperature rise of the intake air in the intake manifold 1 ′ (comparative example) having no bridge portion. FIG. 8 is an explanatory diagram illustrating the influence of heat release from the engine on the temperature rise of the intake air in the intake manifold 1 having the bridge portion 15 according to the present embodiment.
[0025]
In the intake manifold 1 'of FIG. 7, since the heat radiation from the engine body 2' to the space 16 'is directly transmitted to the branch portions 11' and 12 ', the heat radiation from the engine body 2' to the space 16 'causes the branch portion 11'. The wall temperatures of 'and 12' tend to rise, greatly affecting the temperature rise of the intake air passing through the intake passages 13 'and 14'. On the other hand, in the intake manifold 1 according to the present embodiment shown in FIG. 8, heat radiation from the engine to the space 16 is blocked by the bridge portion 15 and is not directly transmitted to the first branch portion 11 and the second branch portion 12.
[0026]
Further, since the first connecting portion 15b and the second connecting portion 15c are formed to be thin, the contact area between the bridging portion 15 and the first branch portion 11 and the second branch portion 12 is small. Heat is not easily transmitted to the branch portion 11 and the second branch portion 12. As a result, the wall surface temperatures of the first branch portion 11 and the second branch portion 12 are unlikely to rise, and the influence on the temperature rise of the intake air passing through the first intake passage 13 and the second intake passage 14 is small.
[0027]
Further, since the air passage 16a is disposed so as to overlap with the ventilation hole 41 of the front engine cover 40, air flows through the air passage 16a through the ventilation hole 41, and the first branch portion 11 and the second The branch part 12 and the bridge part 15 are cooled. Therefore, the temperature rise of the intake air passing through the first intake passage 13 and the second intake passage 14 is further suppressed.
[0028]
Further, in the intake manifold 1 according to the present embodiment, the contact area between the bridge portion 15 and the first branch portion 11 and the second branch portion 12 is small, and the gas passage portions 17 and 18 are formed substantially in the center of the bridge portion 15. Therefore, since the distance from the gas passage portions 17 and 18 to the branch portions 11 and 12 is large, it is difficult for the heat of the EGR gas to be transmitted to the branch portions 11 and 12. As a result, the wall surface temperature of the branch portions 11 and 12 hardly rises, and the influence on the temperature rise of the intake air passing through the first intake passage 13 and the second intake passage 14 is small.
[0029]
In this way, heat from the engine to the space 16 and heat from the first gas passage 17 and the second gas passage 18 are less likely to be transmitted to the first intake passage 13 and the second intake passage 14 and further flow through the air passage 16a. Since the first branch portion 11, the second branch portion 12, and the bridge portion 15 are cooled by the air, a rise in the temperature of the intake air passing through the first intake passage 13 and the second intake passage 14 is suppressed. As a result, a decrease in the volumetric efficiency of the intake air can be suppressed, and the output of the engine can be improved.
[0030]
Further, since the first connecting portion 15b and the second connecting portion 15c of the bridge portion 15 are formed to be thin, the rigidity of the entire intake manifold 1 can be reduced. As a result, the vibration difference between the first branch portion 11 and the second branch portion 12 can be easily absorbed, and the durability against vibration between banks can be improved.
Further, in the intake manifold 1 according to the present embodiment, the first gas passage portion 17 and the first gas passage portion 17 are connected so that the EGR gas can be supplied to both the first gas passage portion 17 and the second gas passage portion 18 from the discharge hole 33 of the additive gas valve 30. Since the second gas passage portion 18 is arranged close to the second gas passage portion 18, there is no need to provide a pipe for distributing the EGR gas between the additional gas valve 30 and the intake manifold 1. it can. For this reason, the number of parts can be reduced, the work process can be simplified, and the cost of the intake system can be reduced.
[0031]
In addition, in the intake manifold 1 according to the present embodiment, the collector 100 is divided into the first chamber 101 and the second chamber 102, and the output is improved by utilizing the pulsation amplitude in the first chamber 101 and the second chamber 102. Although the intake system is adopted, the first gas passage 17 and the second gas passage 18 are separated by a partition 15d and are not connected to each other, so that the pulsation in the first chamber 101 and the second chamber 102 is performed. Can be prevented from canceling each other, and the output of the engine can be improved.
[0032]
In addition, in the intake manifold 1 according to the present embodiment, the intake passage provided with the intake control valves 61 to 66 is not provided with the communication passage from the first gas passage portion 17 and the second gas passage portion 18, and the EGR gas is supplied. Since it is not supplied, sticking and sticking of the intake control valves 61 to 66 due to EGR gas can be prevented, and the reliability of intake can be improved.
Further, in the intake manifold 1 according to the present embodiment, the branch portion connected to the first cylinder 91 to the sixth cylinder 96 and the bridge portion 15 can be integrally formed by the aluminum die casting method, and the first gas Since the passage 17 and the second gas passage 18 can be formed simultaneously using the core, the number of parts can be reduced, the work process can be simplified, and the cost of the intake system can be reduced.
(2) Other Embodiments In the above embodiment, the first gas passage portion 17 and the second gas passage portion 18 are passages for supplying EGR gas, but the first gas passage portion 17 and the second gas passage portion 18 A passage for supplying blow-by gas or a passage for supplying evaporative fuel vaporized in the fuel tank may be used. When the first gas passage portion 17 and the second gas passage portion 18 are passages for supplying a blow-by gas, the residual scum of oil can be burned in the combustion chamber together with the intake air. When the first gas passage 17 and the second gas passage 18 are passages for supplying fuel vaporized in the fuel tank, the vaporized fuel in the fuel tank may be burned in the combustion chamber together with the intake air. it can.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an intake system to which an intake manifold according to the present invention is applied.
FIG. 2 is an enlarged view of an intake manifold.
FIG. 3 is a plan view showing an arrangement of first and second gas passages formed in an intake manifold and respective cylinders of a V-type six-cylinder engine.
FIG. 4 is an explanatory view illustrating a positional relationship between a discharge hole of an additive gas valve, a first gas passage, and a second gas passage.
FIG. 5 is a plan view of a front chain cover.
FIG. 6 is an explanatory diagram illustrating a positional relationship between a front chain cover and an intake manifold.
FIG. 7 is an explanatory diagram illustrating an influence of heat release from an engine on a temperature rise of intake air in an intake manifold without a bridge portion.
FIG. 8 is an explanatory diagram illustrating an influence of heat release from an engine on a temperature rise of intake air in an intake manifold having a bridge portion according to the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Intake manifold 2 Engine main body 3 1st cylinder head 4 2nd cylinder head 5 1st cylinder bank 6 2nd cylinder bank 11,12 1st and 2nd branch part 13,14 1st and 2nd intake passage 15 Bridge part 16a Air passages 17, 18 First and second gas passage portions 19, 20 First and second communication passages 22 Mounting portion 30 Additional gas valve 40 Front chain cover 41 Vent holes 71 to 76, 81 to 86 Intake ports 91 to 96 First ~ 6th cylinder 100 collector

Claims (12)

An intake manifold for a V-type engine,
An intake branch portion is provided in the inter-bank space of the V-type engine and guides intake air to each of the cylinders of both banks. The intake branch portion is formed with a bridge portion separating the upper space of the inter-bank space from the lower space. A gas passage opening in the section and supplying a secondary additive gas is formed in the bridge section, the intake manifold for a V-type engine. The intake manifold for a V-type engine according to claim 1, wherein a collector portion is provided upstream of an intake branch portion that guides intake air to each cylinder. The gas passage includes a main passage extending along the crankshaft direction and a communication passage extending from the main passage to the intake branch portion, and the main passage is formed along the crankshaft direction near the center of the bridge portion. The intake manifold for a V-type engine according to claim 1 or 2, wherein: The intake manifold for a V-type engine according to any one of claims 1 to 3, wherein a thin fragile portion is formed in the bridge portion. The main passage of the gas passage is divided into a first passage portion that supplies the secondary additive gas to the cylinder of one bank and a second passage portion that supplies the secondary additive gas to the cylinder of the other bank. The intake manifold for a V-type engine according to claim 3 or 4, wherein: The intake manifold for a V-type engine according to claim 5, wherein the first and second passages are provided with an additive gas valve for commonly adjusting an additive gas flow rate. A front chain cover that covers the front end side of the interbank space together with the front end side of the V-type engine, wherein the front chain cover has a ventilation hole formed so as to overlap the upper space of the interbank space when viewed from the front end side. The intake manifold for a V-type engine according to any one of claims 1 to 6, characterized in that: The intake manifold for a V-type engine according to any one of claims 1 to 7, wherein the intake branch portion and the bridge portion are formed integrally. Each cylinder is provided with two intake valves, and the intake branch section is configured to independently guide intake air corresponding to each intake valve, and intake air is guided to one intake valve via an intake control valve. The intake manifold for a V-type engine according to any one of claims 1 to 8, wherein intake air is guided to the other intake valve together with a secondary additive gas from a gas passage. The intake manifold for a V-type engine according to any one of claims 1 to 9, wherein the secondary additive gas is EGR gas. The intake manifold for a V-type engine according to any one of claims 1 to 9, wherein the secondary additive gas is a blow-by gas. The intake manifold for a V-type engine according to any one of claims 1 to 9, wherein the secondary additive gas is an evaporative purge gas vaporized in the fuel tank.

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