JPH03182623A - Internal combustion engine intake system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an intake system for an internal combustion engine, and particularly relates to a primary intake passage for low loads having a small diameter and a secondary intake passage for high loads having a large diameter. The present invention relates to an intake device for an internal combustion engine having a passage.

[Conventional technology]

The manifold includes an intake manifold and an exhaust manifold. The intake manifold maintains the balance of air-fuel mixture during intake, and the exhaust manifold discharges exhaust gas from each cylinder after combustion.

The intake manifold connects the carburetor and each cylinder of the internal combustion engine, and distributes the air-fuel mixture from the carburetor to each cylinder, and is made of aluminum casting or the like.

Furthermore, as shown in FIG. 3.4, the conventional internal combustion engine is provided with an intake boat 116 that communicates with the combustion chamber 114 formed in the cylinder head 106 of the internal combustion engine 102, and this intake boat 116 has a large diameter. A high-load secondary intake passage 122 is connected to the surge tank 11B through a first opening 130. A switching valve 120 that opens the first opening 130 when the internal combustion engine 102 is under high load is disposed in the first opening 130 . In addition, the second surge tank 118
A low-load primary intake ill in which the opening 134 and the third opening 136 on the downstream side of the secondary intake passage 122 have small diameters.
It was connected by Route 128. When the load is low, the switching valve 120 closes the secondary intake passage 122 and the primary intake passage 128 is used, and when the load is high, the switching valve 120 opens the secondary intake passage 122. This secondary intake passage 122 was used.

Furthermore, as an intake system for other internal combustion engines, as disclosed in Japanese Patent Application Laid-Open No. 61-200323, one of two independent intake boats leading to the two intake valves of each cylinder is connected to the engine operating state. In addition to providing an on-off valve that opens and closes according to The closing timing of the installed intake valve is set relatively early to suit inertial supercharging in the low speed range, and the closing timing of the intake valve installed in the intake boat on the opening/closing device side is set relatively early to suit inertial supercharging in the low speed range. There was one that was set relatively slow to suit the inertial supercharging of the engine.

C) Problems to be Solved by the Invention) By the way, in the conventional intake system of an internal combustion engine, the intake boat of the cylinder head and the surge tank are connected by a high-load secondary intake passage having a large diameter.
The surge tank and the downstream side of the secondary intake passage were communicated by a low-load primary intake passage having a small diameter.

As a result, when the load is low, the intake air that has passed from the surge tank through the primary intake passage with a small diameter is transferred to the secondary intake passage with a large diameter.
Since the intake air is sent to the downstream side of the passage, the flow velocity of the intake air decreases, and there is a problem that the intake efficiency cannot be improved.

C. Object of the Invention] Therefore, in order to eliminate the above-mentioned disadvantages, the object of the present invention is to provide a combustion chamber of an internal combustion engine and a surge tank on the upstream side of the intake system so as to be connected to each other by a secondary intake passage via a switching valve. The secondary intake passage is divided into two parts from the upstream side to the downstream side.
By providing a second divided passage and providing a primary air supply passage that opens at the beginning in the surge tank and opens at the end in either the first or second divided passage, the flow rate of intake air can be reduced at low loads. It is possible to prevent this and maintain a good primary flow velocity.
An object of the present invention is to realize an intake device for an internal combustion engine that can increase the flow velocity, improve the intake efficiency, and generate a strong swirl compared to the conventional one.

[Means for solving problems]

In order to achieve this object distantly, the present invention has developed a primary intake passage for low loads having a small diameter and a secondary intake passage for high loads having a large diameter.
In an intake system for an internal combustion engine having a secondary intake passage, the combustion chamber of the internal combustion engine and a surge tank on the upstream side of the intake system are connected by a secondary intake passage via a switching valve, and the secondary intake passage The primary intake passage is divided into two from the upstream side to the downstream side to provide a first and second divided passage, and the primary intake passage is opened at the beginning to the surge tank and ends at either the first or second divided passage. It is characterized by having the following.

[Effect]

With the above configuration, when the internal combustion engine is under low load, the switching valve closes the secondary intake passage, and the intake air in the surge tank passes through the primary intake passage. The fuel flows into either one of the first and second divided passages that open at the end and is fed to the combustion chamber.

When the internal combustion engine is under high load, the secondary intake passage is opened by the switching valve, and the intake air in the surge tank is sent into the combustion chamber through the first and second divided passages of the secondary intake passage. has been done.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

Figure 1.2 shows an embodiment of the invention. Second
In the figure, 2 is an internal combustion engine, 4 is a cylinder block, and 6 is an internal combustion engine.
is a cylinder head, and 8 is a piston. The internal combustion engine 2 is a multi-valve internal combustion engine and has, for example, two intake valves 10.10. In this internal combustion engine 2, a cylinder rad 6 is fixed to the upper side of a cylinder block 4.

A piston 8 is inserted into the cylinder 12 of the cylinder block 4, and a combustion chamber 14 is formed by the lower surface portion of the cylinder head 6, the cylinder 12, and the piston 8. The cylinder head 6 is provided with two intake boats 16, 16 communicating with the combustion chamber 14. This intake boat 16.16 is opened and closed by the intake valve 10, IO.

Further, the combustion chamber 14 of the internal combustion engine 2 and the surge tank 18 on the upstream side of the intake system are connected via a secondary intake passage 22 via a switching valve 20, and the secondary intake passage 22 is connected from the upstream side to the downstream side. The first and second divided passages 24.2 are divided into two.
6 is provided, and a primary air supply road 28 is provided so as to open at the beginning to the surge tank 18 and to open at the end to either one of the first and second divided passages 24, 26.

That is, two intake boats 16.16 communicating with the combustion chamber 14 formed in the cylinder head 6 of the internal combustion engine 2 are provided, and a high-load secondary The intake passage 22 is communicated. This secondary intake passage 22 is communicated with the surge tank 18 through a first opening 30, and a switching valve 20 is disposed in the first opening 30 to open the first opening 30 only when the internal combustion engine 2 is under high load. has been done.

Further, the secondary intake passage 22 is divided, for example, into two in the passage cross-sectional area by the partition part 32 from the upstream side to the downstream side, forming first and second divided passages 24 and 26. There is.

Furthermore, a second opening 34 is provided in the surge tank 18,
The second opening 34 and the secondary intake passage 26 are separated from each other.
, one of the second divided passages 24, 26, for example the first
A third opening 36 provided on the downstream side of the divided passage 24 is communicated with a low-load primary intake passage 28 having a small diameter.

Next, the effect will be explained.

When the internal combustion engine 2 is under low load, the first opening 30 of the secondary intake passage 22 is closed by the switching valve 20, and the intake air in the surge tank 18 is diverted to the second opening 30 as shown in FIG. 1.2. The primary intake passage 28 flows from the section 34 through the primary intake passage 28 into the first divided passage 24 in which the primary intake passage 28 is open at the end, passes only through the first divided passage 24, and flows into the combustion chamber 14 via the intake boat 16. is being sent within.

Furthermore, when the internal combustion engine 2 is under high load, the switching valve 20 closes the second opening 34 of the primary intake passage 28 and opens the first opening 30 of the secondary intake passage 22 to prevent surge. The intake air in the tank 18 passes through the first and second divided passages 24 and 26 of the secondary intake passage 22 and into the combustion chamber 14 via the intake boat 16, as shown by the arrow in FIG. 1.2. is being sent to.

As a result, even when the internal combustion engine 2 is under low load, the primary intake passage 28 with a small diameter and the first divided passage 24 with a small diameter can be separated by 1ff.
It is possible to prevent a decrease in the flow velocity of the intake air and maintain a good primary side flow velocity by making it possible to increase the flow velocity compared to the conventional method, and also to generate a strong swirl. The suction efficiency of the internal combustion engine 2 can be reliably improved, which is advantageous in practice.

In addition, by increasing the flow velocity of the intake air, the tuning speed of inertial supercharging can be lowered, and if the tuning is done at the same speed as the conventional one, the primary intake passage 28 can be adjusted without deteriorating the intake efficiency. The length can be shortened and the intake system can be made more compact.

It should be noted that this invention is not limited to the above-mentioned embodiments, and can be modified in various ways.

For example, in the embodiment of the present invention, the passage cross-sectional area of the secondary intake passage is divided into two to form the first and second divided passages, but intake air is supplied from the primary intake passage. The first divided passage can also be configured to have a smaller passage cross-sectional area than the second divided passage, that is, to be narrower. According to this, the intake flow velocity can be further increased.

〔Effect of the invention〕

As explained in detail above, according to the present invention, the combustion chamber of the internal combustion engine and the surge tank on the upstream side of the intake system are connected by the secondary intake passage via the switching valve, and the secondary intake passage is connected from the upstream side. It is divided into two toward the downstream side, and a first and second divided passage is provided, and a starting end is opened in the surge tank, and the first and second passages are
Since the primary intake passage is provided to open at either end of the divided passage, it is possible to increase the flow velocity of the intake air even when the internal combustion engine is under low load, and to generate a strong swirl, which increases the intake air flow rate. Efficiency can be improved reliably, which is advantageous in practice. In addition, by increasing the flow velocity of intake air, the tuning speed of inertial supercharging can be lowered, and if it is tuned at the same speed as the conventional one, the length of the primary intake passage can be shortened, and the intake air The system can be made compact.

[Brief explanation of drawings]

FIG. L2 shows an embodiment of the present invention, FIG. 1 is a schematic plan view of an intake system for an internal combustion engine, and FIG. 2 is a schematic enlarged sectional view of the intake system for an internal combustion engine. 3.4 shows the prior art of the present invention, FIG. 3 is a schematic plan view of an intake system for an internal combustion engine, and FIG. 4 is a schematic enlarged sectional view of the intake system for an internal combustion engine. In the figure, 2 is an internal combustion engine, 4 is a cylinder block, and 6 is an internal combustion engine.
is the cylinder head, 8 is the piston, 10 is the intake valve,
I2 is the cylinder, 14 is the combustion chamber, 16 is the intake port, 1
8 is a surge tank, 20 is a switching valve, 22 is a secondary intake passage, 24 is a first divided passage, 26 is a second divided passage, 28 is a primary air supply passage, 30 is a first opening, 32 is a partition, 34 is a second opening, and 36 is a third opening. Patent applicant representative Suzuki Motor Co., Ltd.

Claims (1)

[Claims] 1. In an intake system for an internal combustion engine equipped with a primary intake passage for low loads having a small diameter and a secondary intake passage for high loads having a large diameter, the combustion chamber of the internal combustion engine and the upstream side of the intake system The surge tank is connected to the surge tank by a secondary intake passage through a switching valve, and the secondary intake passage is divided into two from the upstream side to the downstream side to provide a first and second divided passage, and the surge tank is connected to the surge tank. An intake system for an internal combustion engine, characterized in that the primary air supply passage is provided with an opening at its beginning and an opening at either one of the first and second divided passages.