Induction system for v-type internal combustion engines

Claim 2

An induction system for a V-type internal combustion engine having a first bank (1B) and a second bank (1A) of cylinders (C) respectively, shifted with respect to each other in the direction of alignment of the cylinders, and including intake ports (8) on the side facing the space between the first and second banks; fuel injection means (36) for injecting fuel into the cylinders, each provided in the vicinity of a respective one of the intake ports; fuel distributing means (37a, 37b) for distributing fuel to the fuel injection means arranged in the direction of alignment of the cylinders in the space between the first and second banks; characterized by first (13) and second (14) surge tanks having a predetermined inner volume and being arranged in the direction of alignment of the cylinders above the first bank (1B), each feeding intake air to one of the banks, the first surge tank overlying the second surge tank; first independent intake passages (11) each connected at one end to the side of the first surge tank (13) and at the other end to one of the intake ports of the cylinders constituting the first bank (1 B), second independent intake passages (10) each connected at one end to the side of the second surge tank (14) and at the other end with one of the intake ports of the cylinders constituting the second bank (1A), the first - (11) and second (10) independent intake passages consisting of downstream intake passages - (10b,11b) and upstream intake passages (10a,11a), each downstream intake passage (10b,11b) being connected with one of the intake ports (8) and extending toward a space between the fuel distributing means, and each upstream intake passage - (10a,11a) being curved above the fuel distributing means (37b) for distributing fuel to the fuel injector means of the first bank (1 B) and connected at one end to the downstream intake passages and at the other end to the first or second surge tank respectively.

Claim 3

An induction system for a V-type internal combustion engine having a first bank (1B) and a second bank (1A) of cylinders (C) respectively, shifted with respect to each other in the direction of alignment of the cylinders, and including intake ports (8) on the side facing the space between the first and second banks; a surge tank (12) having a predetermined inner volume for feeding intake air to banks, the surge tank (12) being arranged above the first bank (1B) in the direction of alignment of the cylinders, first independent intake passages - (11) each connected at one end to a side of the surge tank (12) and at the other end to one of the intake ports (8) of the cylinders constituting the first bank (1 B); second independent intake passages - (10) each connected at one end to a side of the surge tank (12) and at the other end to one of the intake ports (8) of the cylinders constituting the second bank (1 A); characterized in that the first independent intake passages (11) are connected with the surge tank (12) at a point higher than the point at which the second independent intake passages (10) are connected with the surge tank (12), the first and second independent intake passages respectively consisting of downstream intake passages (10b,11b) connected at one end to the intake ports and upstream intake passages (10a,11a) connected at one end to the downstream intake passages and at the other end to the surge tank (12), each downstream intake passage (10b,11b) extending toward a space between the first and second banks from one of the intake ports (8), each upstream intake passage (10a,11a) extending curvedly from a connecting portion where it is connected with the downstream intake passage - (10b,11b) to the surge tank (12), the connecting portion being substantially horizontal, the first upstream intake passages (11 a) and the first downstream intake passages (11 b) being curved in the same direction, and the second upstream intake passages (10a) and the second downstream intake passages (10b) being curved in opposite directions.

Claim 4

An induction system for a V-type internal combustion engine having a first bank (1B) and a second bank (1A) of cylinders (C) respectively, shifted with respect to each other in the direction of alignment of the cylinders, and including intake ports (8) on the side facing the space between the first and second banks; a surge tank (12) having a predetermined inner volume for feeding intake air to banks, the surge tank (12) being arranged above the first bank (1B) in the direction of alignment of the cylinders, first independent intake passages - (11) each connected at one end to a side of the surge tank (12) and at the other end to one of the intake ports (8) of the cylinders constituting the first bank (1 B); second independent intake passages - (10) each connected at one end to a side of the surge tank (12) and at the other end to one of the intake ports (8) of the cylinders constituting the second bank (1 A); characterized in that the first independent intake passages (11) are connected with the surge tank (12) at a point higher than the point at which the second independent intake passages (10) are connected with the surge tank (12), the first and second independent intake passages respectively consisting of downstream intake passages (10b,11b) connected at one end to the intake ports and upstream intake passages (10a,11a) connected at one end to the downstream intake passages and at the other end to the surge tank (12), each downstream intake passage (10b,11b) extending toward a space between the first and second banks from one of the intake ports (8), each upstream intake passage (10a,11a) extending curvedly from a connecting portion where it is connected with the downstream intake passage - (10b,11b) to the surge tank (12), the connecting portion being substantially horizontal, the first upstream intake passages (11 a) and the first downstream intake passages (11 b) being curved in the same direction, and the second upstream intake passages (10a) and the second downstream intake passages (10b) being curved in opposite directions.

Claim 5

An induction system in accordance with claim 2, which further includes fuel injection means (36) for injecting fuel into the cylinders, each being provided in the vicinity of one of the intake ports - (8) and fuel distributing means (37a,38b), for dis- . tributing fuel to the fuel injection means (36), arranged in the direction of alignment of the cylinders in the space between the first and second banks, the fuel injection means (36) for the first bank and the fuel distributing means (37b) for the first bank being arranged in a space defined by the first upstream (11 a) and downstream (11 b) intake passages, the fuel injecting means (36) for the second bank and the fuel distributing means (37a) for the second bank being arranged in a space above the second downstream intake passages - (10b).

Claim 6

An induction system in accordance with claim 14 in which the surge tank (12) consists of a first surge tank (13) connected with the first independent intake passages (11) and a second surge tank (14) connected with the second independent intake passages (10), the first surge tank (13) overlying the second surge tank (14).

Claim 7

An induction system in accordance with any of claims 1 to 4, in which the first and second banks (1B, 1A) are arranged with a relative bank angle of 60°.

Claim 8

An induction system in accordance with claim 1 or claim 4, in which the first and second surge tanks (13, 14) have a long box-like shape and are separated from one another by a partition wall (15).

Claim 9

an induction system in accordance with any of claims 1 to 6, in which the first and second surge tanks (13,14) are shifted in the direction of alignment of the cylinders relative to one another, and in which a communicating passage (26) for connecting the first and second surge tanks is provided in a space formed by the lower side portion or the upper side portion of one of the first and second surge tanks and the end portion of the other surge tank, a communication controlling valve (27) for controlling an opening of the communicating passage (26) being provided in the communicating passage.

Claim 10

An induction system in accordance with claim 7, in which the communicating passage (26) is connected at one end to the lower side portion of the first surge tank (13) and at the other end to the end portion of the second surge tank (14).

Claim 11

An induction system in accordance with any of claims 1 to 8, further including first and second independent intake supplying passages (21a,21b) having a predetermined length provided upstream of the first (13) and second (14) surge tanks respectively for supplying intake air into the first and second surge tanks respectively.

Claim 12

An induction system in accordance with claim 9, in which each of the first and second independent intake supplying passages (21 a, 21b) is connected with one end (13a,14a) of the first and second surge tanks respectively.

Claim 13

An induction system in accordance with any of claims 1 to 10, in which the first bank (1B) is disposed rearward of an output shaft of the engine disposed laterally with respect to the longitudinal direction of the vehicle.

Claim 14

An induction system in accordance with any of claims 1 to 11, in which the upstream intake passages (10a,11a) and the downstream intake passages (10b,11b) are connected together at a substantially horizontal surface (F).

Claim 15

An induction system in accordance with claim 12, which further includes an upper flange - (16) formed integrally with all of the upstream intake passages(10a,11a) at the downstream end thereof and a lower flange (17) formed integrally with all of the downstream intake passages - (10b.11b) at the end thereof and in which the upstream intake passages and the downstream intake passage are connected by connecting the upper and lower flanges.

Claim 16

An induction system in accordance with claim 13, in which the upper and lower flanges are connected by bolts, and which includes a boss portion (16a) provided on the upstream intake passages (11 a) for the first bank and projected upwardly between the upstream intake passages.

Claim 17

An induction system. in accordance with claim 1 or claim 4, in which a bank of openings of the first surge tank (13) to be connected with the first independent intake passages (11) is arranged to be shifted relatively from that of the second surge tank (14) to be connected with the second independent intake passages (10) in the direction of the alignment of the cylinders and in which the first upstream intake passages (11a) are arranged above the second upstream intake passages (10a).

Claim 18

An induction system in accordance with claim 1 or claim 4, in which the first upstream intake passages (11) are arranged to extend upwardly from the first surge tank (13) in the vicinity thereof.

Claim 19

An induction system in accordance with any of claims 1 to 16, in which each of the first upstream (11 a) and downstream (11 b) intake passages are connected smoothly with each other and in which the tangential plane of the outer surface of the first upstream and downstream intake passages at the connecting portion meets the connected surface thereof at a right angle.