JPS6341569Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a fuel injection type internal combustion engine in which fuel is injected and supplied to each cylinder. This relates to an intake device for introducing the air.

[Conventional technology and its problems]

In a fuel injection type internal combustion engine in which fuel is injected and supplied to each cylinder, an intake port is formed in the cylinder head and communicates with the combustion chamber of each cylinder via an intake valve. An intake pipe for guiding air into the intake port is connected to one side of the cylinder head,
A fuel injection nozzle is attached to the upper surface of the intake pipe in a direction such that the fuel injected from the fuel injection nozzle is directed toward the intake valve.

In this case, conventionally, as described in JP-A-54-74021 or JP-A-57-110765, the axis of the intake pipe at the connecting portion to the intake port and the axis of the intake port The axis of the connecting portion to the intake pipe is oriented substantially horizontally in a side view of the internal combustion engine, and the intake port is curved obliquely downward toward the combustion chamber from the laterally substantially horizontal direction.

In this way, the axis of the connection part of the intake pipe to the intake port and the axis of the connection part of the intake port to the intake pipe are configured to be substantially horizontal when viewed from the side of the internal combustion engine. In order to facilitate installation of the fuel injection nozzle in an inclined manner so that the injected fuel from the fuel injection nozzle is directed toward the intake valve, and by placing the fuel injection nozzle as close to the combustion chamber as possible, This is to prevent the size from increasing.

However, in this way, the axis of the connection part of the intake pipe to the intake port, and the axis of the connection part of the intake port to the intake pipe,
When viewed from the side of the internal combustion engine, the engine is placed horizontally and horizontally.
If the intake port is curved diagonally downward toward the combustion chamber from a substantially horizontal sideways direction, the angle of curvature from the substantially horizontal sideways direction to diagonally downwards increases, and this large curved angle This obstructs the direction of the intake air flow from the intake pipe to the combustion chamber via the intake port, and the flow velocity of the intake air, which not only reduces the air filling efficiency but also weakens the intake swirl in the combustion chamber. Therefore, the work to improve combustion by intake swirl was reduced.

Moreover, since the axis of the intake pipe and the axis of the intake port are in a substantially horizontal straight line, there is another problem in that the mixture of the fuel injected from the fuel injection nozzle and the intake air is low.

The object of the present invention is to provide an intake device that eliminates these problems.

[Means to solve the problem]

In order to achieve this object, the present invention forms an intake port in the cylinder head that communicates with the combustion chamber of each cylinder via an intake pipe, and the intake port has a
An intake pipe for guiding air into the intake port is connected to one side of the cylinder head, and a fuel injection nozzle is connected to the upper surface of the intake pipe in a direction such that the injected fuel from the fuel injection nozzle heads toward the intake valve. In a fuel injection internal combustion engine, the axis of the intake port at the connecting portion to the intake pipe is inclined diagonally downward toward the combustion chamber when viewed from the side of the internal combustion engine; The axis of the connecting portion to the intake port is inclined diagonally downward toward the combustion chamber when viewed from the side of the internal combustion engine, and the axis of the intake pipe is aligned with the axis of the intake port so that the axis of the intake pipe is directed toward the ceiling of the intake port. It has a structure that allows it to bend.

[Functions and effects of the idea]

In this way, the axis of the intake port at the connection part to the intake pipe and the axis of the intake pipe at the connection part to the intake port are tilted diagonally downward in the direction of the combustion chamber when viewed from the side of the internal combustion engine. As in the conventional art, the bending angle of the intake port is such that the axis of the intake port at the connecting portion to the intake pipe and the axis at the connecting portion of the intake pipe to the intake port are aligned horizontally in a side view of the internal combustion engine. In other words, the flow of intake air from the intake pipe to the combustion chamber via the intake port will not be greatly curved and will flow into the combustion chamber in a nearly straight line. This makes it possible to significantly reduce the flow directionality and intake flow velocity from being inhibited by the curvature angle at the intake port.

On the other hand, by bending the axis of the intake pipe at the connection part to the intake port with respect to the axis of the intake port so that the axis is directed toward the ceiling of the intake port, the axis of the intake port and the axis of the intake pipe are A fuel injection nozzle is installed between the top surface of the intake pipe and one side of the cylinder head, with both sides inclined diagonally downward toward the combustion chamber when viewed from the side of the internal combustion engine. Space can be secured to install the fuel in such a direction that the fuel is directed toward the intake valve. In other words, the fuel injection nozzle can be mounted on the top surface of the intake pipe so that the injected fuel from the fuel injection nozzle is directed toward the intake valve. This makes it possible to avoid increasing the difficulty of mounting the engine by slanting both the axis of the intake port and the axis of the intake pipe diagonally downward toward the combustion chamber.

In addition, as described above, by bending the axis of the connection part of the intake pipe to the intake port with respect to the axis of the intake port so that the axis line points toward the ceiling of the intake port, the upper surface of the intake pipe Being able to secure a space for installing the fuel injection nozzle between the cylinder head and one side of the cylinder head can reduce the separation of the fuel injection nozzle from the combustion chamber, so the axis of the intake port and the axis of the intake pipe can be By slanting both of them downward toward the combustion chamber, it is possible to minimize the increase in size of the internal combustion engine.

Moreover, by bending the axis of the intake pipe at the connection part to the intake port with respect to the axis of the intake port so that the axis is directed toward the ceiling of the intake port, the intake air in the intake pipe is directed in the direction of the axis. After flowing, it collides with the ceiling of the intake port and changes the flow in the axial direction of the intake port, so the fuel injected from the fuel injection nozzle is quickly transferred to the intake air heading toward the ceiling of the intake port. They can be mixed.

Therefore, according to the present invention, it is difficult to install a fuel injection nozzle on the upper surface of the intake pipe connected to the intake port so that the injected fuel from the fuel injection nozzle is directed toward the intake valve, and the increase in the size of the internal combustion engine The effect of being able to reliably strengthen the intake air swirl flow into the combustion chamber without increasing the flow rate, improve air filling efficiency, and reliably improve the mixing properties of fuel and intake air. has.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawing, reference numeral 1 indicates a cylinder 3 in which a first cylinder A1, a second cylinder A2, and a third cylinder A3 are arranged in a line along a crankshaft (not shown). A cylinder internal combustion engine is shown, and the cylinder head 2 has two intake ports 3a, 3b, 4a, and 2 for each cylinder, respectively.
4b, 5a, 5b are provided to open on one side 6 of the cylinder head 2, and intake valves 7a, 7b,
8a, 8b, 9a, and 9b are provided, respectively.

Reference numeral 10 indicates a surge tank connected to an atmospheric air intake passage 11 from an air cleaner (not shown), and the surge tank 10 and the intake ports 3a, 3b, 4a, 4b, 5a, 5b in each cylinder.
and six intake pipes 13a, 13b, 14a, 14b, 15a, 15 connected to one side 6 of the cylinder head 2 at a common flange 12.
Each is connected separately and independently via b.

Both intake pipes 13a, 13b for the first cylinder A1
The upper surface of both intake pipes 14a for the second cylinder A2,
14b, and the upper surfaces of both intake pipes 15a, 15b for the third cylinder A3, there are fuel injection ports for injecting and supplying fuel toward the intake valves 7a, 7b, 8a, 8b, 9a, 9b in each cylinder. Nozzles 16, 17, and 18 are provided, respectively.

The length of the intake path from the surge tank 10 to the combustion chamber in each cylinder is set so that the amount of intake air is maximum in a certain rotation range of the internal combustion engine.

Each of the intake ports 3a, 3b, 4a,
4b, 5a, 5b, the portion near one side 6 of the cylinder head 2, that is, each intake pipe 13a, 1
3b, 14a, 14b, 15a, and 15b are configured to be inclined diagonally downward toward the combustion chamber by an appropriate angle θ from the horizontal line 20 when the internal combustion engine 1 is viewed from the side.

On the other hand, each of the intake pipes 13a, 13b, 14a,
14b, 15a, 15b, the axis 21 at the connecting portion to each of the intake ports 3a, 3b, 4a, 4b, 5a, 5b is set at an appropriate angle α from the horizontal line 20 in the side view of the internal combustion engine 1. The respective intake pipes 13a, 13b, 14a, 14b, 15
The axes 21 of a and 15b correspond to the respective intake ports 3a and 3
b, 4a, 4b, 5a, 5b, each intake port 3a, 3b, 4a, 4b, 5
It is configured to be bent at an appropriate angle β with respect to the axis 19 of a and 5b.

In this way, each intake port 3a, 3b, 4a,
4b, 5a, 5b, each intake pipe 13a, 13
b, axis 19 at the connecting portion to 14a, 14b, 15a, 15b, and each intake pipe 13a,
Each intake port 3a, 3b, 4a, 4b, 5a, 5 among 13b, 14a, 14b, 15a, 15b
By slanting the axis 21 at the connecting portion to the internal combustion engine diagonally downward in the direction of the combustion chamber in a side view of the internal combustion engine, each intake port 3a, 3
b, 4a, 4b, 5a, 5b are smaller than when these axes 19, 21 are oriented horizontally in a side view of the internal combustion engine, and each intake pipe 13a, 13b, 14a, 1
4b, 15a, 15b to each intake port 3a, 3
b, 4a, 4b, 5a, 5b to the combustion chamber is in a nearly straight line, and each intake pipe 13a, 13b, 14a, 1
The axis 21 of 4b, 15a, 15b is the axis 2
1 is each intake port 3a, 3b, 4a, 4b, 5
Each intake pipe 13a, 13b, 14a, 14 is bent by an appropriate angle β with respect to the axis 19 of each intake port so as to face the ceiling surface of each intake port 13a, 13b, 14a, 14.
b, 15a, 15b flows in the direction of its axis 21 as shown by the arrow 22 in FIG. 2, and then collides with the ceiling surface of each intake port and changes its flow in the axial direction of each intake port. Therefore, the fuel injected and supplied from each of the fuel injection nozzles 16, 17, and 18 rides on the intake air directed toward the ceiling surface of the intake port and is quickly mixed with the intake air.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view of an internal combustion engine, and FIG. 2 is a cross-sectional view taken from the side of FIG. 1. 1... Internal combustion engine, 2... Cylinder head, 3a, 3
b, 4a, 4b, 5a, 5b...Intake port, 6...
One side of cylinder head, 7a, 7b, 8a, 8
b, 9a, 9b...Intake valve, 10...Surge tank,
13a, 13b, 14a, 14b, 15a, 15
b... Intake pipe, 16, 17, 18... Fuel injection nozzle, 19... Axis of intake port, 20... Horizontal line, 2
1...Axis of the intake pipe.

Claims (1)

[Scope of utility model registration request] an intake pipe for directing air into the intake port, connected to the intake port on one side of the cylinder head; and a fuel injection nozzle attached to an upper surface of the intake pipe in a direction such that fuel injected from the fuel injection nozzle is directed toward the intake valve, wherein the axis of the intake port at the connection portion to the intake pipe is inclined obliquely downward toward the combustion chamber in a side view of the internal combustion engine, while the axis of the intake pipe at the connection portion to the intake port is inclined obliquely downward toward the combustion chamber in a side view of the internal combustion engine, and the axis of the intake pipe is bent with respect to the axis of the intake port so that it is directed toward the ceiling surface of the intake port.