JPH109071A - Intake device of multiple cylinder internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve intake efficiency in the wide rotational range of an engine, and arrange a piping in a compact size by providing an air cleaner and a surge tank in a multiple cylinder in-line engine on one side of the intake port side arranged in series in a cylinder, and providing a bending part on the other side arranged in series in the cylinder of an intake pipe. SOLUTION: A surge tank 30 and an intake port 14 are connected to the intake pipe 28 of a six cylinder engine. An intake control valve 32 is arranged in the serge tank 30, by closing the intake control valve 32 the inside of the surge tank 30 is divided into two chambers 34, 36. An intake pipe 46 is provided on the upper part of a cylinder head cover 12, and the surge tank 30 and an air cleaner are communicated with each other. A throttle valve 52 is arranged in the intake pipe 46, the downstream of the throttle valve 52 is divided into two intake pipes 47a, 47b, and each intake pipes 47a, 47b are communicated with respective chambers 36, 34. A bending part is set in each of intake pipes 47a, 47b, and the surge tank 30 and the air cleaner 48 are communicated with each other through the bending part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for an internal combustion engine, and more particularly to an intake system for a multi-cylinder internal-combustion engine whose output is improved by a dynamic effect of intake air of a multi-cylinder in-line engine. It is.

[0002]

2. Description of the Related Art Conventionally, in an intake system of an internal combustion engine, a negative pressure wave generated at the start of intake is reflected at the open end to the atmosphere or an expansion chamber on the upstream side of an intake passage and becomes a sinusoidal wave in the direction of the intake port. Utilizing the fact that the sine wave is returned, the sine wave reaches the intake port just before the intake valve is opened, and the intake is pushed in, so that the so-called inertia effect of intake enhances the charging efficiency of intake. . When such a technique is used, if the shape of the intake passage is constant, the vibration cycle of the pressure wave generated in the intake passage matches the opening / closing cycle of the intake valve, and the inertia effect can be enhanced only in a specific rotation range. Can be

[0003] For example, the intake passage of Japanese Patent Application Laid-Open No. 61-226515 (hereinafter referred to as "prior art") has a short high-speed passage linearly extending to an intake port of an engine and an upper portion of a cylinder of the engine (an upper portion of a cylinder head cover). There is disclosed a technique in which a normal passage extending parallel to the high-speed passage and bent by 180 degrees and connected to the high-speed passage, and a throttle valve for switching the high-speed passage and the normal passage at this connection portion. In the conventional intake passage, when the engine is running at a low speed, the throttle valve is opened to use the service passage as the intake passage, and when the engine is running at a high speed, the throttle valve is closed to use the high-speed passage as the intake passage. Thus, efficient intake characteristics can be obtained in a wide rotation range.

[0004]

However, in the above-mentioned prior art, it is necessary to arrange a plurality of air cleaners as intake ports by providing two intake passages having different lengths. There are significant restrictions on mounting in the engine room.

[0005] The service passage extends above the cylinder of the engine, and the service passage is provided with an air cleaner adjacent to the exhaust passage of the engine. The arrangement of the air cleaner adjacent to the exhaust passage has an adverse effect on engine characteristics. That is, the exhaust gas after combustion by the engine flows in the exhaust passage of the engine, and is higher in temperature than the intake passage. On the other hand, when the service passage is used, the air heated by the exhaust passage is used as the intake gas for the air cleaner, and the weight flow rate of the intake air flowing through the service passage is reduced.
A desired engine output cannot be obtained.

The present invention discloses an intake device for a multi-cylinder internal combustion engine that solves the above-mentioned problems of the prior art.

[0007]

Means taken in the first aspect of the present invention is an air intake system for a multi-cylinder internal combustion engine having an air cleaner and a surge tank, and a throttle valve is provided between the air cleaner and the surge tank. In a suction device of a multi-cylinder internal combustion engine, which is connected through a first intake pipe provided with the same, and connected between the surge tank and the intake port of each cylinder through the same number of second intake pipes as the cylinders, The surge tank is arranged on one side of the intake port side of the series arrangement of the cylinders, and the first intake pipe is provided with a bent portion on the other side of the series arrangement of the cylinders. Therefore, it is possible to arrange the first intake pipe above the internal combustion engine to secure a passage length. Further, since the air cleaner is disposed adjacent to the relatively low-temperature intake passage away from the high-temperature exhaust passage, the intake air is efficiently supplied to the internal combustion engine without increasing the temperature of the intake air supplied to the internal combustion engine. It becomes possible to inhale.

According to a second aspect of the present invention, the surge tank is divided into a plurality of surge tank chambers by an intake control valve having a surge tank disposed therein, and the first intake pipe is branched and connected to each surge tank chamber. Is provided. Accordingly, the intake control valve is closed in a low-speed region requiring a long intake passage, and the intake control valve is opened in a high-speed region requiring a short intake passage, and the length of the intake passage is switched according to the speed. It is possible to perform effective intake to the internal combustion engine.

The measure taken in the third aspect of the present invention is that a bent portion is provided at the branch portion. Therefore, the diameter of the branch portion of the first passage pipe in the bent portion can be reduced,
The first intake pipe can be reduced in size.

According to a fourth aspect of the present invention, the branch portion is provided between the throttle valve arranged in the first intake pipe and the plurality of surge tank chambers. Therefore,
It is possible to secure the length of the branch portion.

[0011]

An embodiment according to the present invention will be described with reference to the drawings.

FIG. 1 schematically shows an intake system for an engine using the present invention, and FIG. 2 shows a side sectional view of FIG. 10 is a piston cylinder (cylinder),
Reference numeral 12 denotes a cylinder head cover, and the illustrated engine is a six-cylinder engine having six cylinders. An intake port 14 and an exhaust port 16 are provided at an upper portion of each piston cylinder 10. An intake valve 18 and an exhaust valve 20 are provided at the intake port 14 and the exhaust port 16, respectively. These are cams 22, 24 attached to a cam shaft (not shown).
It opens and closes by the rotation of. Reference numeral 26 denotes an exhaust pipe for discharging combustion gas from the exhaust port 16 to a muffler (not shown). In FIG. 1, exhaust pipes 26 provided for each cylinder are indicated by 26a to 26f. 28
Denotes an intake pipe (second intake pipe) which connects the surge tank 30 having a fan-shaped cross section and the intake port 14 arranged in parallel with the cylinder head cover.

An intake control valve 3 is provided inside the surge tank 30.
When the intake control valve 32 is closed, the inside of the surge tank 30 is connected to the first chamber 34 and the second chamber 34.
The room 36 is divided into two. The intake pipes 28a, 28b and 28c are connected to the first room 34, and the intake pipes 28d, 28e and 28f are connected to the second room 36. The intake control valve 32 controls the negative pressure of the negative pressure tank 38 by the ECU.
It can be opened and closed by supplying to an actuator (diaphragm) 44 via a negative pressure control valve 42 by means of 40.

An intake pipe (first intake pipe) 46 is provided above the cylinder head cover 12 and communicates between the surge tank 30 and the air cleaner 48. 50
Is the air intake of the air cleaner. Intake pipe 46
Is provided with a throttle valve 52, and the intake pipe 4
6 is opened and closed by an actuator (not shown) in accordance with the opening degree of the accelerator. The intake pipe 46 downstream of the throttle valve (on the side of the surge tank 30) is divided into two intake pipes 47a and 47b. The intake pipe 47a communicates with the first chamber 34 of the surge tank 30, and the intake pipe 47b communicates with the second chamber 36 of the surge tank 30. The intake pipes 47a and 47b are provided with curved portions, and the curved portions allow the surge tank 30 disposed on the intake port side of the cylinder head cover 12 to communicate with the air cleaner 48. The curved portions of the intake pipes 47a and 47b are located on the exhaust port side of the cylinder head cover 12.

The operation of the above embodiment will be described.

When each cylinder enters the intake process, outside air is sucked into the air cleaner 48 from the air intake port 50 by the negative pressure generated as the piston 13 in the cylinder descends. The sucked outside air is filled into each cylinder from the intake valve 18 via the first intake pipe 46, the throttle valve 52, the intake pipes 47a and 47b, the surge tank 30, and the second intake pipe 28. At this time, the opening of the throttle valve 52 is adjusted according to the driving situation.

In this embodiment, the ECU
An engine speed signal is input to 25, and it is determined whether the engine speed is higher or lower than a preset engine speed (N).

In a region where the engine speed is lower than a predetermined value (N), the intake control valve 32 is closed to divide the inside of the surge tank 30 into a first chamber 34 and a second chamber 36. On the other hand, in a region where the engine speed is higher than the predetermined value (N), the intake control valve 32 is opened, the section between the first chamber 34 and the second chamber 36 is removed, and one inside the surge tank 30 is removed. Room. Therefore, as can be seen from the graph showing the relationship between the engine speed and the output (shaft torque) in FIG. 3, in the region where the engine speed is lower than the predetermined value (N), the first engine speed is lower than the throttle valve 52. The first room 34, the second room 36, the intake pipe 47a, and the intake pipe 47b are each used as a resonance chamber (resonator), and the intake air to be charged into the cylinder in a low-speed region where the engine speed is equal to or lower than a predetermined value (N). High output can be obtained by increasing the filling efficiency. Conversely, in a region where the engine speed is higher than a predetermined value (N), the surge tank 30
Are used as resonance chambers attached to the second intake pipes 28a to 28f, and increase the charging efficiency of the intake air charged into the cylinder in a high-speed region where the engine speed is equal to or higher than a predetermined value (N).
High output can be obtained.

Therefore, the charging efficiency of the intake air according to the predetermined engine speed (N) can be ensured, and by arranging the air cleaner on the intake port side of each cylinder,
Desired engine characteristics can be obtained without inhaling the air heated by the exhaust of the engine.

In this embodiment, only one intake control valve 32 is provided inside the surge tank 30 so that the inside of the surge tank 30 is divided into the first chamber 34 and the second chamber 3.
Although the inside of the surge tank 30 can be further finely divided by arranging a plurality of intake control valves 32, the inside is divided into two.

The surge tank 30 and the air cleaner 4
8, the first intake pipe is branched so that a large resonance chamber can be secured in a low-speed range where the engine speed is equal to or lower than a predetermined value (N), and the charging efficiency is increased.
High output of the engine can be obtained.

[0022]

According to the first aspect of the present invention, the air cleaner and the surge tank are arranged on one side of the intake port side of the cylinders arranged in series, and the first intake pipe is arranged on the other side of the cylinders arranged in series. Since the first intake pipe is provided at the upper part of the internal combustion engine, the passage length can be secured. In addition, since the air cleaner is disposed adjacent to the relatively low-temperature intake side passage away from the high-temperature exhaust side passage, the intake air is efficiently supplied to the internal combustion engine without increasing the temperature of the intake air supplied to the internal combustion engine. Can be inhaled.

According to the second aspect of the present invention, the surge tank is divided into a plurality of surge tank chambers by the intake control valve disposed therein, and the first intake pipe is branched and connected to each surge tank chamber. With the branch, the intake control valve is closed in the low-speed range that requires a long intake passage, and the intake control valve is opened in the high-speed range that requires a short intake passage. Can be switched, and effective intake to the internal combustion engine can be performed.

According to the third aspect of the present invention, since the bent portion is provided at the branch portion, the diameter of the branch portion of the first passage pipe at the bent portion can be reduced, and the size of the first intake pipe can be reduced. Can be.

According to the fourth aspect of the present invention, since the branch portion is provided between the throttle valve arranged in the first intake pipe and the plurality of surge tank chambers, the length of the branch portion can be ensured. .

[Brief description of the drawings]

FIG. 1 schematically shows an intake device for a multi-cylinder internal combustion engine according to an embodiment of the present invention.

FIG. 2 shows a side view of FIG. 1;

FIG. 3 shows a torque characteristic according to an engine speed in the embodiment of the present invention.

[Explanation of symbols]

 28 second suction pipe 30 surge tank 46 first suction pipe 48 air cleaner 47a, 47b branch 52 throttle valve

Claims (4)

[Claims] 1. An intake device for a multi-cylinder internal combustion engine having a series arrangement of an air cleaner and a surge tank, wherein the air cleaner and the surge tank are connected via a first intake pipe having a throttle valve, In an intake device for a multi-cylinder internal combustion engine in which the surge tank and the intake port of each cylinder are connected via the same number of second intake pipes as cylinders, the air cleaner and the surge tank are arranged in series with the cylinder. An intake device for a multi-cylinder internal combustion engine, wherein the intake device is disposed on one side of an intake port side, and wherein the first intake pipe has a bent portion on the other side of the series arrangement of the cylinders. 2. The surge tank is divided into a plurality of surge tank chambers by an intake control valve disposed therein.
2. The intake device for a multi-cylinder internal combustion engine according to claim 1, wherein the first intake pipe includes a branch portion branched and connected to each surge tank chamber. 3. The intake device for a multi-cylinder internal combustion engine according to claim 2, wherein the branch portion is provided with the bent portion. 4. The intake device for a multi-cylinder internal combustion engine according to claim 3, wherein the branch portion is provided between a throttle valve disposed in the first intake pipe and the plurality of surge tank chambers. .