JPH01104923A - Intake device for engine - Google Patents

Abstract

PURPOSE:To intensify the swirl at a low or intermediate speed and reduce the swirl in the high speed operation and improve the fuel consumption and output by twisting a partitioning wall which dividingly forms a plurality of ports and inclining said partitioning wall in the vicinity of the joint surface with a cylinder head. CONSTITUTION:During the time when an engine operates at a low or intermedi ate speed, the second intake pipe 7 is closed by a control valve 9, and the intake supplied from a surge tank 8 is supplied into the primary ports P1-P4 of an intake manifold 1 from the first intake pipe 6. When the engine operates at a high speed, the control valve 9 is opened, and the intake supplied from the surge tank 8 is supplied into the primary and secondary ports P1-P4 and S1-S4 from the first and second intake pipes 6 and 7. In this constitution, a partitioning wall 1c which constitutes the primary and secondary ports P1 and S1 which are contiguous each other is twisted in the vicinity of the opened port edge 1b and formed aslant at the opened port edge 1b.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an engine intake system.

(Conventional technology and its problems) As a measure to improve engine performance, it is necessary to form a homogeneous mixture and a strengthened swirl especially at low speeds. In order to form the strengthened swirl at low speeds (when the secondary valve is closed), a primary port and a secondary port for forming a strong swirl must be provided separately from each other, or from what source the swirl can be strengthened. For example, a primary port is arranged below the secondary port, and the upstream end of the primary port is placed upstream of the intake control valve (secondary valve) of the secondary port, and the downstream end is placed downstream of the intake control valve and of the cylinder head. It is necessary to take measures such as communicating with one of the intake ports and opening it facing the tangential direction of the back of the valve umbrella to create a bias in the flow of intake air.

For this reason, the structure of the intake system becomes complicated,
There is a problem that it is expensive.

The present invention has been made in order to solve the above-mentioned problems, and provides an engine intake system that has a simple structure but can generate effective swirl at low speeds, and can reduce swirl at high speeds. The purpose is to provide.

(Means for Solving the Problems) According to the present invention, in order to achieve the above object, first and second
ports, each end of which is connected to the intake system,
Each other end is connected to an intake port that has two intake valves and is integrally opened on the side end surface of the cylinder head. At low and medium speeds, the first port is connected to the first port, and at high speeds, the first port and the second port are connected to each other.
In an intake system for an engine in which the engine is operated by a port, the partition wall defining the first port and the second port is twisted and inclined in the vicinity of a mating surface with a side end surface of the cylinder head. It is.

(Operation) At low and medium speeds, most of the intake air supplied from the first port to the intake port of the cylinder head flows directly from one intake valve to the combustion chamber, and the remainder flows from the other intake valve to the combustion chamber. As a result, the flow of air supplied into the combustion chamber becomes uneven, and an effective swirl occurs. Furthermore, at high speeds, the intake air flows straight from the first and second ports toward the intake port, and as a result, the imbalance of the intake air supplied to the combustion chamber is corrected, and the occurrence of swirl is suppressed. .

(Example) An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

1 to 4 show an intake manifold constituting a part of an intake system to which the present invention is applied, and the intake manifold 1 has, for example, four cylinders and two intake valves and two exhaust valves. It is applied to a so-called 4-valve engine (Fig. 6), and has four first ports (hereinafter referred to as primary ports) PL-P4 and four second ports (hereinafter referred to as secondary ports) Sl-S4. have. The primary port P1 and the secondary port 31 constitute an intake passage for one cylinder. Similarly, P2 and S
2. P3 and S3, and P4 and S4 constitute the intake passage of each other cylinder.

These primary ports PI to P4 and each secondary port (Sl-S4) have a circular shape as shown in FIG. 1b has a substantially trapezoidal opening as shown in FIG. In addition, intake manifold 1
Primary bow opening on one end surface 1a) P 1~
By arranging the open ends of P4 and Sl-S4 obliquely as described above, it is easy to arrange the intake pipes connected to these open ends.

On the other hand, on the end surface 1b of the intake manifold 1, the primary ports P1 to P4 and the secondary ports 5l to 34 are alternately arranged approximately horizontally and open, and define adjacent primary ports PI and secondary ports SL. The partition wall 1c is twisted near the opening end 1b, and is formed obliquely at the opening end 1b. And one side of the PI (primary port) is the secondary port S1
It is placed diagonally below the opposite sides of the The intake manifold 1 having such a shape is integrally formed of a casting like a normal intake manifold.

As shown in FIG. 5, this intake manifold 1 has an end face 1b.
is fixed in contact with the side end surface of the cylinder head 2 of the engine, and each open end of the primary port PI and secondary port S1 is connected to the open end of the corresponding intake port 2a of the cylinder. One end of this intake bow 2a is integrated and opens at the side end surface of the cylinder rad 2, and the other end is 2a.
Each section is opened facing the combustion chamber 3 (Fig. 6.7), and each is equipped with an intake valve 4.5.

In addition, the intake manifold 1 has one end of a first intake pipe 6 and a second intake pipe 7 connected to each open end of a primary port PL and a secondary port S1 that open on the end surface 1a, respectively. Each other end of the tube 6.7 is connected to a surge tank 8.
connected to. Each of the other primary ports P2 to P4 and secondary ports) 32 to S4 are also connected to the primary port P.
Similarly to the I and secondary ports SL, one end of each is connected to the corresponding intake port of the cylinder head, and the other end is connected to the surge tank 8 via first and second intake pipes (not shown).

Each second intake pipe 7 is provided with a control valve 9 near its mating surface with the opening end 1a of the intake manifold 1, and each of these control valves 9 is connected to an actuator via a shaft 11 and a link 12. 13 shirt l-13a. This actuator 13 is connected to a control device (not shown), and controls the opening and closing of the control valves 9 according to the engine speed. Open the valve at

The action will be explained below.

In FIGS. 6 and 7, when the engine is at low or medium speed, each second intake pipe 7 is closed by the control valve 9, and the intake air from the surge tank 8 is taken from each first intake pipe 6. It is supplied to each primary port P1 to P4 of the manifold 1. The intake air supplied to these primary ports P1 to P4 flows into the cylinder from each open end of the end surface 1b to each corresponding intake port 2a of the rad 2.

At this time, most of the intake air flowing out from the primary port P1 flows straight into the combustion chamber 3 through the intake valve 4 from the intake port 2a as shown by the solid arrow A. In addition, the primary port PI is located at the lower side of the exit Pla (
4) obliquely enters below the outlet of the secondary port S2, the intake air flowing out from the lower side Pla, that is, a part of the intake air flowing out from the primary port P1 is absorbed as shown by the solid arrow B. Intake valve 5 from port 2a
It flows into the combustion chamber 3 through. As a result, the flow of intake air flowing into the combustion chamber 3 is biased, and an effective swirl is generated within the combustion chamber 3 as shown by arrow C.

When the engine is running at high speed, the control valve 9 of each second intake pipe 7 is opened, and the surge tank 8 is passed through each first intake pipe 6 and each second intake pipe 7 to each corresponding primary port PL of the intake manifold 1. -P4 and each secondary port 5L-34
The air is supplied to each corresponding intake port 2a of the cylinder head 2 through the air.

The intake air flowing out from the primary port P1 and the secondary port 31 flows straight into the intake port 2a as indicated by the dotted arrow E, and flows into the combustion chamber 3 through each intake valve 4.5. As a result, the bias in the flow of intake air flowing into the combustion chamber 3 is corrected, and the swirl within the combustion chamber 3 is significantly reduced or eliminated.

FIG. 9 is a characteristic diagram showing the relationship between engine ignition timing and idling fuel consumption, where the solid line shows the characteristics when the intake system of the present invention is used, and the dotted line shows the characteristics when the conventional intake system is used. As is clear from this characteristic diagram, fuel efficiency during idling can be improved. Further, FIG. 10 is a characteristic diagram showing the relationship between the swirl ratio and the fuel consumption when the ignition timing is constant. As shown in FIG. 8, the swirl ratio is determined by the length A of the upper side of the opening end of the primary port P1 and the length B of the lower side, for example, A = 24 mm, B - 30 mm.
In the case of , the characteristic shown by the solid line in Fig.
.

When B=40m-, the characteristic is shown by the dotted line. Also,
The dashed line shows the case where a conventional intake device is used.

As is clear from this characteristic diagram, fuel efficiency can be improved.

(Effects of the Invention) As explained above, according to the present invention, the cylinder head has first and second ports, one end of each of these ports is connected to the intake system, and each other end is connected to the two intake valves. It is connected to an intake port that is integrally opened on the side end surface of the
In an intake system of an engine in which the engine is operated by the first port and the second port at high speeds, the partition wall defining the first port and the second port is twisted to connect with the side end surface of the cylinder head. By slanting the area near the joint, it is possible to bias the intake air flow at low and medium speeds and generate an effective swirl, thereby improving fuel efficiency at idle and at low and medium speeds. At high speeds, it becomes possible to correct the imbalance of the intake air flow and significantly reduce the occurrence of swirl, thereby improving the filling efficiency and increasing the output. Furthermore, the intake device has excellent effects such as a simple port structure for generating swirl and can be provided at low cost.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of an intake manifold constituting a part of an engine intake system according to the present invention, FIG. 2 is a side view of FIG. 1, and FIG. directional end view,
Fig. 4 is an end view in the direction of the arrow ■ in Fig. 2, Fig. 5 is a partially cutaway configuration diagram of an intake system to which the intake manifold shown in Fig. 1 is applied, and Fig. 6 is a main part of the intake system shown in Fig. 5. FIG. 7 is a diagram showing the air flow in FIG. 6, FIG. 8 is a diagram showing the shape of the primary port in FIG. 4, and FIG. 9 is a diagram showing the shape of the primary port in FIG. 4. A characteristic diagram showing the relationship between the ignition timing and the idle fuel consumption, and FIG. 1θ is a characteristic diagram showing the relationship between the ignition timing and the fuel consumption at constant ignition timing when the intake manifold according to the present invention is applied. 1...Intake manifold, primary port for PI~P4, 31~S4...Secondary port, 2...
・Cylinder head, 3... Combustion chamber, 4.5... Intake valve, 6.7... Intake pipe, 8... Surge tank, 9...
...Control valve, 11...Shaft, 12...Link,
13...actuator. Applicant Mitsubishi Motors Corporation Agent Patent Attorney Kanji Nagato Figure 1 Figure 2 Figure 3 Figure 4 Figure 1a Figure 8 Figure 9 Figure 10

Claims (2)

[Claims] (1) Has a first and second port, one end of each of these ports is connected to the intake system, and each other end is connected to an intake port that has two intake valves and opens integrally on the side end surface of the cylinder head. is,
In an intake system for an engine in which the engine is operated by the first port at low and medium speeds and by the first and second ports at high speeds, the first port and the second port are operated.
1. An intake system for an engine, characterized in that a partition wall defining a port is twisted so as to be inclined in the vicinity of a mating surface with a side end surface of the cylinder head. (2) The engine intake device according to claim 1, wherein the partition wall is inclined so that the first port slightly enters below the second port.