JPH02241924A - Inertial supercharging type intake device in internal combustion system - Google Patents

Abstract

PURPOSE:To improve the output between high and low speed rotation regions by closing a first control valve in a low speed intake pipe path in a medium speed rotation region while opening a second control valve in a medium speed intake pipe path. CONSTITUTION:There are provided two intake pipe paths, a low speed intake pipe path 6a having the sectional area set smaller to match with inertial supercharging in the low speed rotation region of an internal combustion engine 1 and a medium speed intake pipe path 6b having the sectional area set larger to match with the inertial supercharging in the medium speed rotation region of the engine 1. A first controlling valve 8 opened in both the low speed rotation region and high speed rotation region exceeding the medium speed rotation region and closed in the medium speed rotation region is provided in each low speed intake pipe path 6a, and a second controlling valve 10 opened in both the medium and high speed rotation regions and closed in the low speed rotation region is provided in the medium speed intake pipe path 6b. Thus, the output between the high and low speed rotation regions can be improved by the inertial supercharging in the medium speed rotation region.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a structure in which a surge tank for eliminating pulsation provided downstream from an air cleaner and a combustion chamber in each cylinder are connected to an independent intake pipe for each cylinder. The present invention relates to an improvement in an intake device that performs intake by inertial supercharging by connecting through a channel.

[Conventional technology]

By connecting the surge tank for pulsation elimination provided downstream from the air cleaner and the combustion chamber in each cylinder via an independent intake pipe for each cylinder,
It is well known that air intake is performed by inertial supercharging.

In this case, the natural oscillation of pressure vibration in the intake pipe which connects the surge tank and the combustion chamber of each cylinder independently for each cylinder. However, in this equation 0, a is the speed of sound, and ■ is the surge tank , S is the cross-sectional area of the intake pipe, and L is the length of the intake pipe (actually, the length from the surge tank to the combustion chamber).

When the natural frequency f of the pressure vibration matches the frequency of the rotational speed in the internal combustion engine, the effect of intake inertia can be obtained, so the length of each intake pipe is increased. By shortening the length of the intake pipe or by increasing the cross-sectional area, it is possible to obtain inertia supercharging that matches the low speed rotation range.
It is possible to obtain inertia supercharging that matches the high speed rotation range.

However, the effect of inertial supercharging can only be obtained in a specific rotation range corresponding to a preset length as mentioned above, and in other rotation ranges, intake is performed by inertia supercharging. Not only is it impossible to do so, but a phenomenon occurs in which the output actually decreases.

Therefore, Japanese Unexamined Patent Application Publication No. 110765/1983 as a prior art discloses the connection between the surge tank located downstream of the air cleaner and the combustion chamber of each cylinder in FIGS. 3 and 4. each of which is connected by independent intake pipes, each of the intake pipes being composed of two, a long-length low-speed intake pipe and a short-length high-speed intake pipe, A control valve that closes in the low-speed rotation range is installed in the high-speed intake pipe, so that only the low-speed intake pipe is connected in the low-speed rotation range, and in addition to the low-speed intake pipe in the high-speed rotation range. The proposal is to expand the rotational range in which intake can be performed by inertial supercharging into two rotational ranges: a low-speed rotational range and a high-speed rotational range, by connecting the high-speed intake pipe with the engine.

[Problem to be solved by the invention]

However, with this prior art, intake by inertia supercharging can only be performed in two rotation ranges: a low speed rotation range and a high rotation speed range, and between these two rotation ranges, There is a valley where intake cannot be performed by inertial supercharging, and the output of the internal combustion engine is significantly reduced in this valley, so the drivability of the internal combustion engine is significantly deteriorated. When performing inertia supercharging in both the low-speed rotation range and the high-speed rotation range by using a long low-speed intake pipe line and a short high-speed intake pipe line, the low-speed intake pipe line and the high-speed intake pipe line In other words, the length of the low-speed intake pipe must be considerably longer than the length of the high-speed intake pipe. Therefore, the structure of the intake device becomes complicated and large.

An object of the present invention is to provide an inertial supercharging type intake device that solves the problems of the prior art.

[Means to solve the problem]

In order to achieve this object, the present invention connects a surge tank provided downstream of an air cleaner in an intake path and a combustion chamber in each cylinder of an internal combustion engine through an independent intake pipe for each cylinder. , in the intake system that performs inertia supercharging through each of the intake pipes, each of the intake pipes is configured to have a low-speed intake whose cross-sectional area is set to be small to match inertia supercharging in the low-speed rotation range of the internal combustion engine. The pipe is composed of two pipes, and a medium-speed intake pipe whose cross-sectional area is set large to match inertial supercharging in the medium-speed rotation range of the internal combustion engine, and each of the low-speed intake pipes has a ,
A first control valve that opens in both the low-speed rotation range and a high-speed rotation range exceeding the medium-speed rotation range and closes in the medium-speed rotation range is disposed in each of the medium-speed intake pipes. The second control valves are each provided with a second control valve that opens in both the medium-speed rotation range and the high-speed rotation range and closes in the low-speed rotation range.

[Action/effect of the invention]

In this configuration, in the low-speed rotation range of the internal combustion engine, the second control valve in the medium-speed intake pipe closes, while the first control valve in the low-speed intake pipe opens, so that each cylinder of the internal combustion engine Since air is taken into the combustion chamber through the low-speed intake pipe having a small cross-sectional area, inertial supercharging that matches the low-speed rotation range can be obtained.

In addition, in the medium-speed rotation range of the internal combustion engine, the first control valve in the low-speed intake pipe closes, while the second control valve in the medium-speed intake pipe opens, causing combustion in each cylinder of the internal combustion engine. Since air is taken into the chamber through the medium-speed intake pipe having a large cross-sectional area, inertial supercharging that matches the medium-speed rotation range can be obtained.

In the high-speed rotation range of the internal combustion engine, the first control valve in the low-speed intake pipe and the second control valve in the medium-speed intake pipe open together, allowing air to flow into the combustion chamber of each cylinder of the internal combustion engine. Since the intake air is carried out through both the low-speed intake pipe and the medium-speed intake pipe, and the cross-sectional area increases, it is possible to obtain inertial supercharging that matches the high-speed rotation range.

Therefore, according to the present invention, in an intake pipe that independently connects one surge tank and each combustion chamber in each cylinder into two intake pipes, the intake air by inertial supercharging is It can be performed for three rotation ranges: low speed rotation range, medium speed rotation range, and high speed rotation range.In other words, the output between the output in the low speed rotation range and the output in the high speed rotation range is Since this can be improved by inertial supercharging, the drivability of an internal combustion engine can be improved.

In this case, the present invention performs matching of inertial supercharging for each rotation range in the low-speed intake pipe and the medium-speed intake pipe by setting the cross-sectional areas of the low-speed and medium-speed intake pipes. Since there is no need to make a large difference between the length of the low-speed intake pipe and the length of the medium-speed intake pipe as in the prior art, the structure of the intake system can be simplified and the size can be reduced. can be achieved.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A multi-cylinder internal combustion engine has a cylinder A3, and reference numeral 2 indicates a surge tank. A throttle body 3 having a built-in throttle valve is connected to one end of the surge tank 2.
An intake passage 4 from an air cleaner (not shown) is connected to the throttle body 3.

the surge tank 2 and each cylinder At of the internal combustion engine 1;
A2. The intake boat 5 to the combustion chamber in A3 is connected to each cylinder A1. A2. Independent intake pipe line 6 for each of A3
Each of these intake pipes 6 is composed of two pipes: a low-speed intake pipe 6a with a small inner diameter D1, and a medium-speed intake pipe 6b with a large inner diameter D2. .

In this case, the cross-sectional area of the low-speed intake pipe 6a with the inner diameter D1 is determined when the rotational speed of the internal combustion engine 1 is, for example, about 300 Or
The intake pipe line 6 for medium speeds has an inner diameter of D2 and is set so that intake air can be achieved by inertia supercharging at a low rotational speed of pm.
The cross-sectional area at b is set so that intake air can be achieved by inertial supercharging at a medium-speed rotational speed of the internal combustion engine 1, for example, about 400 Orpm, and the cross-sectional area of the low-speed intake pipe 6a and the medium-speed The total cross-sectional area of the intake pipe 6b for internal combustion engine l is, for example, approximately 5000
Settings are made so that intake air can be achieved by inertial supercharging in a high rpm range.

In each of the low-speed intake pipes 6a, there is a motor connected to the rotation speed of the internal combustion engine 1 via an actuator 7,
The rotation speed of the internal combustion engine 1 is at the low speed rotation speed (approximately 300
a low speed rotation range below approximately the middle rotation speed (about 350 Orpm) between the medium speed rotation speed (about 400 Orpm) and the medium speed rotation speed (about 400 Orpm); Approximately middle rotation speed (approximately 45
0Orpm) and a high speed rotation range of more than 0Orpm), and the rotation speed is from approximately the middle rotation speed (about 350Orpm) between the low speed rotation speed (about 3000rpm) and the medium speed rotation speed (about 400Orpm) to the medium speed. Rotation speed (approx. 400O
Each of the first control valves 8 is provided with a first control valve 8 that closes in a mid-speed rotation range (approximately 450 Orpm) between the high-speed rotation speed (approximately 500 Orpm) and the high-speed rotation speed (approximately 500 Orpm). Also in the passage 6b is the internal combustion engine 1.
is related to the rotation speed in the internal combustion engine 1 through the actuator 9, and the medium speed rotation range (about 350 Or, pm to 4500 rpm) and the high speed rotation range (about 450 Or, pm to 4500 rpm) in the internal combustion engine 1.
The configuration is such that the second control valves 10 are each provided with a second control valve 10 that opens in two rotational speed ranges, i.e., above 350 rpm) and closes in the low speed rotational range (about 350 rpm or less).

In this configuration, the rotational speed in the internal combustion engine 1 is about ζ
In the low-speed rotation range below 50 Orpm, the second control valve 10 in each medium-speed intake pipe 6b closes, while the first control valve 8 in each low-speed intake pipe 6a opens, so that the internal combustion engine 1, each cylinder At, A2. Since air is taken into the combustion chamber in A3 through the low-speed intake pipe 6a with a small cross-sectional area, the rotational speed is 350 rpm.
It is possible to obtain inertia supercharging that matches the following low speed rotation range.

Further, the rotation speed in the internal combustion engine 1 is approximately 350 Qrpm.
to 450 Orpm, the first control valve 8 in each low-speed intake pipe 6a closes, while the second control valve 10 in each medium-speed intake pipe 6b opens, so that the internal combustion Each cylinder of engine Y: Al, A, 2. Since air is taken into the combustion chamber in A3 through the medium-speed intake pipe 6b having a large cross-sectional area, the rotational speed is approximately 350 O.
It is possible to obtain inertia supercharging that matches the medium speed rotation range from rpm to 450 rpm.

Furthermore, the rotational speed of the internal combustion engine 1 is approximately 450 Or
In the high-speed rotation range above pm, each low-speed intake pipe 6
The first control valve 8 in a and each medium speed intake pipe 6b
By opening both the second control valves 10 in the internal combustion engine 1, each cylinder Al of the internal combustion engine 1.

A2. Air is taken into the combustion chamber in A3 through both the low-speed intake pipe 6a and the medium-speed intake pipe 6b, and the cross-sectional area increases, so the rotational speed is approximately 450 rpm.
It is possible to obtain inertia supercharging that matches the higher speed rotation range.

In addition, when configuring the intake air by inertia supercharging to the internal combustion engine 1 to be matched to three equally spaced rotational speeds of 3000 rpm, 4000 rpm, and 5000 rpm as in the above embodiment, each low-speed intake pipe 6a
The cross-sectional area S1 and length are set to match inertial supercharging of 3000 rpm, while the length of each medium-speed intake pipe 6b is set to be the same or approximately the same as the length of the low-speed intake pipe 6a. In this state, S2 in each medium-speed intake pipe 6b may be configured to be 16/9 times the cross-sectional area S1 in the low-speed intake pipe 6a.

In other words, the natural frequency f of the pressure vibration in each intake pipe is proportional to the cross-sectional area of the intake pipe < r
cx5). If the natural frequency that matches the rotational speed of 300Orpm is f3, the natural frequency that matches the rotational speed of 400Orpm is f4, and the natural frequency that matches the rotational speed of 5000rpm is f5, then the rotational speed is 300Orpm.
To match the three equally spaced rotation speeds of pm, 4000 rpm, and 5000 rpm, f 4 - f 3 -
If the relationship f5-f4 is established and the above s1 and 82 are substituted into this, then we get F74 〒=, β1T ko 1 7 zo cho d... Since the formula is 0, we can calculate S・2 from this. Further, in the above embodiment, the low-speed intake pipe 6a and the medium-speed intake pipe 6b are arranged side by side so that the lengths of both are made equal, but as shown in FIG. By arranging the low-speed intake pipe 6a on the outside of the curved radius of the curved medium-speed intake pipe 6b, the length of the low-speed intake pipe 6a can be made shorter than that of the middle-speed intake pipe. It may be configured to have an appropriate length longer than the length of 6b.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, and FIG. 1 is a partially cutaway plan view of the first embodiment, FIG. 2 is a shallow concave view along the line nn of FIG.
The figure is a mm-m shallow concave view of FIG. 1, and FIG. 4 is a sectional view of the second embodiment. 1... Internal combustion engine, AI, A2. A3...Cylinder,
2...Surge tank, 3...Throttle body 4...Intake passage from air cleaner, 5...Intake port, 6...Intake pipe line, 6a...For low speed Intake pipe line, 6b...Intake pipe line for medium speed, 8...1st
Control valve, 10...Second control valve.

Claims (1)

[Claims] (1) The surge tank provided downstream of the air cleaner in the intake path and the combustion chamber in each cylinder of the internal combustion engine are connected via an independent intake pipe for each cylinder, and each intake pipe In an intake system that performs inertial supercharging, each of the intake pipes has a low-speed intake pipe whose cross-sectional area is set to be small to match inertial supercharging in a low-speed rotation range of an internal combustion engine, and a low-speed intake pipe whose cross-sectional area and a medium-speed intake pipe set large enough to match the inertia supercharging in the medium-speed rotation range of the internal combustion engine, and each low-speed intake pipe has a large intake pipe for the low-speed rotation range. , a first control valve that opens in both the medium speed rotation range and the high speed rotation range exceeding the medium speed rotation range, and closes in the medium speed rotation range; An inertial supercharging intake system for an internal combustion engine, characterized in that second control valves are provided, each of which opens in both a rotation range and the high speed rotation range, and closes in the low speed rotation range.