JPS626252Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention has two parts in the cylinder head for one cylinder.
A throttle valve device that switches the intake air flow to the two intake ports in a dual intake multi-cylinder internal combustion engine that has two intake ports and opens and closes communication between the two intake ports to the combustion chamber using one intake valve. Regarding.

In a dual-intake multi-cylinder internal combustion engine, in the low-load range of the engine, intake air passes through only one low-load intake port to create a strong swirl in the combustion chamber air-fuel mixture to improve combustion, while in the high-load range, the intake air passes through only one low-load intake port. The intake port is opened to allow intake air to flow through both ports, increasing the amount of intake air and ensuring engine output. In order to switch the intake air flow between the two intake ports in this way, conventionally, one of the intake ports in the cylinder head is provided with a throttle valve and this is opened and closed, or the intake air flow connected to the two intake ports in the cylinder head is connected to the throttle valve. A throttle valve was provided in one of the two intake passages of the manifold branch to open and close it. However, when attempting to actually mass-produce such a conventional device, the number of precision-machined parts such as the throttle valve mounting hole increases, and it is necessary to install a large number of throttle valve operating parts, making the installation extremely complicated and making assembly into the engine difficult. It became difficult and production efficiency decreased significantly (Jikko 46-9930).
(see publication).

In view of the above-mentioned drawbacks of the conventional throttle valve, the present invention replaces the throttle valve built into the cylinder head or intake manifold and the operation mechanism that opens and closes these valves in series, and extends the throttle valve between the cylinder head and the intake manifold across the row of cylinders. Productivity is greatly improved by assembling the unit in advance into a generally plate-shaped integral spacer interposed so as to extend, and by simply setting the unit during engine assembly. The purpose is to

Its gist is that it is an integral, generally plate-shaped body that is interposed between the cylinder head and the intake manifold and extends across the cylinder row, and has two mounting surfaces on both sides of the body, and is attached to the primary side of the cylinder head. and a spacer in which the primary side intake passage and the secondary side intake passage are passed through in parallel between these mounting surfaces so as to communicate with the secondary side intake port, and a throttle valve is installed in the secondary side intake passage. The spacer and the intake manifold are jointly fastened to the cylinder head, and the spacer and the intake manifold are fixed together to the cylinder head.

An embodiment of the present invention will be described below based on the drawings.

In FIG. 1, a primary side intake port 1 and a secondary side intake port 2 are connected to a combustion chamber 4 by one intake valve 3.
A flange at the downstream end of a branch portion of an intake manifold 8 having one intake passage 7 for each cylinder is attached to the intake manifold mounting surface of the cylinder head 5, which is configured to open and close communication with the cylinder head 5, via a spacer 6 according to the present invention. The intake manifold 8 has a two-barrel carburetor 13 having a primary throttle valve 11 and a secondary throttle valve 12 connected to the upstream end of the intake manifold 8.

As shown in the figure, the spacer 6 has a generally plate-like integral shape extending across the cylinder row, and has two mounting surfaces facing the mounting surfaces of the cylinder head 5 and the intake manifold 8 on both sides thereof, and has the primary side intake port. A primary side intake passage 21 and a secondary side intake passage 22, which correspond to and communicate with the secondary side intake port 1 and the secondary side intake port 2, are passed through in parallel between the mounting surfaces. These primary side intake passage 21 and secondary side intake passage 22
The throttle valve 23 (23a to 23d) is interposed in the secondary intake passage 22 corresponding to each cylinder. As shown in FIG. 2, these throttle valves 23a to 23d each have a single shaft 24 in a straight line, and a throttle valve opening/closing operation mechanism (not shown) is connected to one end of the shaft 24, so that they can be opened and closed simultaneously. Make it. As a specific example of the aperture valve opening and closing mechanism, it may be mechanically linked to the accelerator pedal or the secondary side aperture valve 12, or the negative pressure of the intake manifold, the negative pressure of the intake passage, and the exhaust pressure. A negative pressure actuator or an electromagnetic actuator that detects the operating state in which an output is required and operates based on the detected signal may be used.

The outline of the operation of this embodiment is as follows. That is, in the engine low load range, the primary throttle valve 11 of the carburetor 13
is controlled to open and close, so that the secondary throttle valve 12 is fully closed, and each throttle valve 23 in the spacer 6 is fully closed, so that only the primary intake passage 1 is open. Therefore, the intake air-fuel mixture is sucked into the intake manifold 8 in an amount corresponding to the opening degree of the primary throttle valve 11.
The air is drawn into each combustion chamber 4 through the primary side intake passage 21 and the primary side intake port 1 via the intake valve 3. In this case, since the downstream end of the primary intake port 1 is arranged in a spiral shape around the outer periphery of the secondary intake port 2, a strong swirl is generated in the intake air-fuel mixture flowing into the combustion chamber 4, resulting in combustibility. This improves the leanness limit of the air-fuel mixture, improving exhaust performance and fuel efficiency.

When the engine is in a high load state, the secondary throttle valve 12 in the carburetor 13 is also opened, and the throttle valve 23 in the spacer is also opened simultaneously by the operation of an operation mechanism (not shown) and the rotation of the shaft 24. be excused. Therefore, the intake air-fuel mixture flows through the secondary throttle valve 1.
2, the amount is increased through the intake manifold 8, and the increased amount is supplied to the combustion chamber 4 through the secondary side intake passage 22 where the throttle valve 23 is located, through the secondary side intake port 2, and through the intake valve 3. Therefore, engine output is improved.

In the figure, 14 is an exhaust port, and 15 is a spark plug mounting hole.

The one shown in FIG. 3 is constructed by defining the intake passage 7 in the intake manifold 8 in the above embodiment into two intake passages 31 and 32, one on the primary side and the other on the secondary side, thereby forming an intake system on the primary side. The structure is such that the combustion chamber is separated from the secondary side and joins for the first time in the combustion chamber 4.
Its operation is not essentially different from that of the above embodiment.

It is clear that the present invention is applicable not only to the carburetor type internal combustion engine of the embodiment but also to a fuel injection type internal combustion engine.

Further, the present invention is fully applicable to a dual-intake internal combustion engine of the type in which communication between the primary side intake port and the secondary side intake port is opened and closed with the combustion chamber by two different intake valves.

As described above, according to the present invention, in a dual-intake multi-cylinder internal combustion engine, the secondary-side intake port is connected to the secondary-side intake port of each cylinder and is equipped with a throttle valve that controls opening and closing of the intake air flow in the passage. An integral, substantially plate-shaped spacer having a passageway and a primary side intake passage communicating with the primary side intake port and extending across the cylinder row is interposed between the cylinder head and the mounting surface of the intake manifold, and each throttle valve is Since it is configured to open and close in conjunction with a single shaft, the throttle valve and the mechanism for operating it in series can be pre-assembled into the spacer only, and then assembled at the time of engine assembly, so machining of the throttle valve mounting part is required. Furthermore, it is not necessary to assemble the throttle valve operating mechanism during engine assembly, and production efficiency in mass production lines is greatly improved. Further, performing precision machining and assembling parts in advance on a spacer having a simple structure is much easier and more productive than performing the above machining and assembling on an engine or intake manifold with a complex structure. Furthermore, even if a failure occurs in the throttle valve and its operating mechanism, there is no need to replace the entire intake manifold as in the conventional case, and only the spacer is required.

Furthermore, since the primary side intake passage and the secondary side intake passage are made to pass through in parallel between the mounting surfaces provided on both sides of the integral substantially plate-shaped spacer extending across the cylinder row, the intake manifold and Since the mounting directions of the spacer and the cylinder head are substantially the same, they can be fastened together, and the spacer equipped with the throttle valve can be assembled very easily without being affected by the number of cylinders. Furthermore, since the spacer that extends integrally across the cylinder row is provided with a shaft for sequentially opening and closing each throttle valve, the shaft can be easily attached to the spacer.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view showing one embodiment of the intake pipe device according to the present invention, Fig. 2 is a view taken along arrow A-A of the same, and Fig. 3 is a schematic cross-sectional view of another embodiment of the present invention. It is a diagram. 1...Primary side intake port, 2...Secondary side intake port, 3...Intake valve, 4...Combustion chamber, 5...Cylinder head, 6...Spacer, 8...Intake manifold, 21...Primary Side intake passage, 22... Secondary intake passage, 23 (23a to 23d)... Throttle valve,
24...Shaft.

Claims (1)

[Scope of Claim for Utility Model Registration] In a dual-intake multi-cylinder internal combustion engine in which communication between the primary side intake port and the secondary side intake port is opened and closed to the combustion chamber by one intake valve, a branch part of the intake manifold and A spacer is interposed between the cylinder head and the intake manifold and is fixed to the cylinder head by tightening together with the intake manifold, and the spacer has an integral substantially plate shape extending across the cylinder row, and the spacer is interposed between the cylinder head and the intake manifold. A primary side intake passage communicating with the primary side intake port and a secondary side intake passage communicating with the secondary side intake port have respective mounting surfaces for the manifold on both sides of the mounting surface for each cylinder. An intake pipe device for an internal combustion engine, characterized in that a throttle valve is installed in the secondary intake passage of each cylinder in parallel and interlocked to open and close by a single shaft. .