JP2575735B2 - Engine fuel supply - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fuel supply device for an engine.

(Prior Art) In general, an injector applied to a fuel injection type engine is relatively expensive. For this reason, an injector which is conventionally provided one for each cylinder is replaced by a two-hole injector having two nozzles. Attempts have been made to reduce the cost by reducing the number of in-line four-cylinder engines (i.e., sharing injectors), for example, as disclosed in Japanese Utility Model Laid-Open No. 61-49067. 4 connected to each cylinder
It is known that two intake passages are gathered at a time, and two injectors are provided at the gathering portion, one by one each.

By the way, the demand for lowering the cost by sharing such an injector is the same for a V-type multi-cylinder engine, and as a method for solving this, a two-injector injector is used as in the case of the in-line multi-cylinder engine described above. It is possible to do.

However, in the V-type multi-cylinder engine, it is difficult to apply the above-mentioned conventional technology (that is, to share the injector by adopting the two-hole injector) for the following reasons.

That is, in a normal V-type multi-cylinder engine, a surge tank is arranged at an upper position between the left and right banks, and the surge tank is connected to each cylinder of both banks by an intake passage. The passage will be located below the surge tank. On the other hand, when a pair of intake passages respectively connected to the cylinders of the left and right banks are brought close to each other between the two banks, and a two-injector injector is mounted in this proximity, the amount of fuel supplied to both intake passages is reduced as much as possible. In order to equalize the diameter, it is necessary to provide the two-hole injector downward from directly above the adjacent portion. For these reasons, when a two-injector injector is installed in a V-type multi-cylinder engine, it is necessary to set the position of the surge tank at a high position in order to avoid mutual interference between the surge tank and the two-injector injector. As a result, the height of the entire engine is increased by the height of the surge tank, which causes an obstacle in engine layout on the vehicle body.

(Object of the Invention) The present invention is intended to solve the problems pointed out in the above-mentioned prior art, and is intended to mount a two-injection injector on a V-type multi-cylinder engine without increasing its size in the height direction. It is an object of the present invention to provide a fuel supply device of an engine which can reduce the cost by making it possible.

(Means for Achieving the Object) The present invention provides V
A surge tank is arranged above the one bank of an engine having a pair of left and right banks inclined in a mold, and between the surge tank and each of the cylinders of the left and right banks, a center portion of the two banks is provided from the surge tank. After a plurality of intake passages extending from the central portion of the two banks toward the cylinders of the two banks and communicating with the cylinders, a plurality of intake passages are sequentially provided in the cylinder arrangement direction. At the center of both banks, fuel is simultaneously injected into the intake passages on both banks between the intake passage communicating with the cylinder on one bank adjacent to the cylinder arrangement direction and the intake passage communicating with the cylinder on the other bank. A two-hole injector is provided so as to obtain the same.

(Operation) In the present invention, by means of the above means, the two-injector injector is connected to the surge tank from the place where the surge tank is disposed above one bank, with respect to the intake passage located between the left and right banks. The surge tank can be mounted from above without being concerned about interference, and the surge tank can be arranged above one bank and as low as possible.

(Embodiment) Hereinafter, a preferred embodiment of the present invention will be described with reference to FIG. 1 to FIG.

FIGS. 1 and 2 show a V-type six-cylinder engine Z for a vehicle equipped with a fuel supply device according to an embodiment of the present invention. The engine Z is a pair of right and left banks inclined in a V-shape, i.e., the first bank X _1, the second cylinder 10B having a first cylinder 10A and the third cylinder 10C and the fifth cylinder 10E If and a second bank X ₂ having a fourth cylinder 10D and the sixth cylinder 10F. The two banks X ₁ and X ₂ are mutually offset in the cylinder arrangement direction such that the cylinder of the other bank is located at the position between the cylinders of one bank.

Each cylinder 10A~10F of both the banks X _1, X _2, as shown in Figure 2, each communicating with the intake port 5 in the bank between a position close intake passage 3A~3F (to be described later) and its Exhaust passages 4, 4,... Communicating with the exhaust port 6 are formed on both sides. An exhaust valve 8 is provided at each exhaust port 6, 6,... Of each cylinder, and an intake valve 7 is provided at each of the intake ports 5, 5,. This engine is a four-valve engine, and has an intake port 5 and an exhaust port 6 for each cylinder.
Are provided two by two.

Each intake passage 3A to 3F communicating with each cylinder 10A to 10F respectively
As shown in FIGS. 1 and 2, the surge tank 9 where the respective intake upstream ends placed on bank X ₁ of the first
And a first intake passage 3 sequentially communicating with the first cylinder 10A.
The openings are arranged in a row in the cylinder arrangement direction from A in the order of the sixth intake passage 3F communicating with the sixth cylinder 10F. And
Each of the intake passages 3A to 3F is first drawn out of the surge tank 9 while bending to the inter-bank position 30, and then the three intake passages 3A, 3C, and 3E on the _first bank X1 side are U-shaped downward. corresponding cylinders 10A inverted for Jo, 10C, respectively communicating with the intake ports 5,5,5 for 10E, while the second bank X ₁ side of the three intake passages 3B, 3D, 3F is substantially S-shaped Each of the cylinders 10B, 10D, and 10F communicates with each of the intake ports 5, 5, 5 while being curved. Thus, the first bank X ₁ side of the intake passage 3A, 3C,
3E and the intake passages 3B, 3D, 3F on the _second bank X2 side are all arranged in the cylinder arrangement direction at the central portion between the banks. Therefore, in this embodiment, the adjacent first bank
X ₁ side of the intake passage and the second bank X ₂ side of the intake passage, i.e., the first air passage 3A and the second intake passage 3B, the third intake passage 3C and fourth intake passages 3D, the fifth intake of Passage 3E and sixth intake passage F
2 and 3 are connected to each other via a partition wall 12 as shown in FIG. 2 and FIG. Each of the connecting portions 14, 14, 14 is provided with a two-injector injector 20A, 20B, 20C, respectively, from above to below, and each of the two-injector injectors 20A, 20B, 20C is connected to a partition 12
And two adjacent intake passages 3A, 3B, 3C, 3D and 3E, 3F through an opening 13 provided at the upper end of the intake passage. In this embodiment, the intake passages 3A to 3F have main passages 3Aa, 3Ba... Each having a large passage area opened and closed by a shutter valve 11 as shown in FIG. 3Ab, 3Bb ..., the shutter valve 11 is opened only during high-load operation of the engine,
Otherwise, the valve is closed. The fuel injected from each of the two-injector injectors 20A, 20B, and 20C is injected toward the shutter valve 11 that is in a closed state during a low-load operation of the engine (see a two-dot chain line arrow in FIG. 2). During high-load operation, the fuel is directly injected into the intake valve 7 through the main passages 3Aa, 3Ba,.

In this way, the two-injector injector is provided between adjacent intake passages so that fuel can be injected into both passages.
When 20A, 20B, and 20C are provided, relatively expensive injectors can be shared between the two intake passages. For example, as compared with the case where one injector is provided for each intake passage, the overall cost is increased. The number of arrangements can be reduced by half, and cost reduction can be promoted accordingly. Further, the two-injection injector can be attached to the V-type engine without increasing the overall height of the engine.
And it is arranged above the bank X _1, the surge tank 9
This is due to avoiding mutual interference between the two nozzles 20A, 20B and 20C.

The cylinders provided in both banks are arranged such that the cylinders of the other bank are located at positions between the cylinders of one bank, and the intake passages 4,
4… is originally close. Therefore, when installing the two injection ports 20A, 20B, and 20C, the intake passage
It is not necessary to curve and approach the 4, 4,..., And it is possible to prevent the intake resistance from increasing due to the bending.

In this embodiment, since the fuel injection direction is set as described above, vaporization and atomization of fuel are promoted as described below, and good combustion performance is obtained. That is, during low load operation in which the shutter valve 11 is closed, radiated fuel directly hits the shutter valve 11 and scatters to the surroundings, so that atomization of fuel is promoted.
During the high-load operation in which is opened, the injection fuel is directly applied to the high-temperature intake valve 7 to promote its vaporization.

Further, the fuel injection is performed by the intake valves 7, 2 of the paired cylinders.
Perform within the period when both are closed. This is because, for example, when fuel is injected during each intake stroke, the shutter valve
At high load when 11 is open (that is, in the operating region where there is no swirl flow), the injected fuel is directly injected into the combustion chamber to deteriorate the safety of combustion, and conversely at low load when the shutter valve 11 is closed. In the region where the swirl flow is generated, the combustion stability is improved. However, when the shutter valve 11 is opened as in a transitional period of acceleration, the swirl disappears with the shutter valve 11 and the combustion performance may deteriorate. In order to avoid this, the fuel injection is performed in the valve closing region of the intake valve.

(Effects of the Invention) The present invention provides a V-type engine having a pair of left and right banks arranged at an angle, the surge tank being disposed above the one bank, and the surge tank being connected to each cylinder of the left and right banks. A plurality of intake passages extending from the surge tank toward the center of both banks in a curved manner and then extending from the center of both banks toward the cylinders of the banks and communicating with the cylinders, respectively. The two banks are arranged between the intake passages communicating with the cylinders on one bank adjacent to each other in the cylinder arrangement direction and the intake passage communicating with the cylinders on the other bank at the center of the two banks. In this case, two injectors are provided in the intake passages so that fuel injection can be performed simultaneously.

Therefore, according to the fuel supply device for an engine of the present invention, (1) from the place where the surge tank is disposed in one bank, the two injection port injectors are connected to the intake passage located between the left and right banks by the surge tank. (2) The surge tank can be mounted above one bank without worrying about the mutual interference between the surge tank and the two-injector injectors. In addition, it is possible to arrange the injectors at the lowest possible position.It is possible to provide two injectors without increasing the size of the engine in the height direction. There is an effect that the cost can be reduced as compared with the case where it is provided.

[Brief description of the drawings]

FIG. 1 shows a V equipped with a fuel supply device according to an embodiment of the present invention.
2 is a plan view of the essential parts of a 6-cylinder engine, and FIG. 2 is II- in FIG.
FIG. 3 is a vertical sectional view taken along the line III-III of FIG. DESCRIPTION OF SYMBOLS 1 ... Cylinder block 2 ... Cylinder head 3A-3F ... Intake passage 4 ... Exhaust passage 5 ... Intake port 6 ... Exhaust port 7 ... Intake valve 8 ... Exhaust valve 9 ... Surge tank 10A-10F …… Cylinder 11 …… Shutter valve 12 …… Bulkhead 20A-20C …… Two-injector injector 21 …… Delivery pipe

Claims (1)

(57) [Claims] 1. An engine having a pair of left and right banks inclined in a V-shape, a surge tank is disposed above the one bank, and a surge tank is disposed between the surge tank and each cylinder of the left and right banks. A plurality of intake passages extending from the surge tank toward the central portions of both banks and then further extending from the central portions of the banks toward the cylinders of the banks and communicating with the respective cylinders are arranged in the cylinder arrangement direction. The intake passages communicating with the cylinders on one bank side adjacent to each other in the cylinder arrangement direction and the intake passages communicating with the cylinders on the other bank side are provided at the central portions of the two banks. A fuel supply device for an engine, characterized in that two fuel injectors are provided so that fuel can be injected simultaneously into the intake passages of both banks.