JPH0913986A - Engine - Google Patents

Abstract

PURPOSE: To reduce the suction quantity/exhaust quantity ratio of an engine and secure the smooth gas flow at the position of an inlet valve. CONSTITUTION: Suction gas moving openings 11 are provided at the cylinder head portions of cylinders 2, they are connected by a ventilation duct 12, and a suction gas moving valve 13 is provided at each suction gas moving opening 11. The opening or closing of each suction gas moving valve 13 is controlled, and part of the suction gas in one cylinder in the compression stroke is moved to another cylinder in the suction stroke via the ventilation duct 12. The suction gas quantity can be practically decreased in one cylinder, and the suction quantity/exhaust quantity ratio can be reduced. The suction gas can be smoothly moved, and the smooth gas flow at the position of an inlet valve can be secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-step engine having a plurality of cylinders, and more particularly to an engine capable of adjusting an intake gas amount.

[0002]

2. Description of the Related Art A typical four-step engine process is shown in FIG.
FIG. The lower side of the figure is a diagram showing the intake, compression, expansion, and exhaust steps for one cylinder, and the upper side is the corresponding crank angle-piston position diagram. As is clear from the figure, the conventional general engine has the same intake amount and exhaust amount (both volumes due to piston movement), and the ratio of the intake amount and the exhaust amount, that is, the intake amount / exhaust amount (hereinafter intake amount).・ It is called the exhaust volume ratio).

Further, as shown in FIG. 8, the intake gas is allowed to flow back toward the carburetor by keeping the intake valve open until a certain angle in the initial stage of the compression process, thereby reducing the intake amount and the intake amount / exhaust amount. In some engines, the amount ratio (intake amount / exhaust amount) is reduced to prevent knocking due to overcompression and to effectively use the energy of combustion gas.

[0004]

The engine according to the method of FIG. 8 can reduce the intake / exhaust volume ratio.
Delaying the closing timing of the intake valve to allow the intake gas to flow back toward the carburetor at the beginning of the compression process
Considering the motion of the intake gas, collision between the intake gas and the backflow gas occurs. When the rotation speed becomes high, the collision phenomenon between the intake gas and the backflow gas causes a hammer phenomenon, which reduces the efficiency of the carburetor and the supercharger. The problem arises.

The present invention has been made in order to solve the above-mentioned conventional drawbacks, and an engine capable of reducing the intake amount / exhaust amount ratio and at the same time ensuring a smooth gas flow at the intake valve position. It is also an object of the present invention to provide an engine that can easily realize setting of the optimum intake / exhaust amount ratio in that case.

[0006]

SUMMARY OF THE INVENTION The present invention, which solves the above problems, provides a four-step engine having a plurality of cylinders, each of which is provided with an intake gas moving opening at the cylinder head portion of each cylinder, A ventilation duct is provided for connecting the intake openings to each other, and an intake gas transfer valve for opening and closing the intake gas transfer opening is provided at each of the intake gas transfer openings of each cylinder. The opening / closing control is performed so that a part of the suction gas in the cylinder is discharged to the ventilation duct in the initial stage of the compression process and moved into another cylinder that has entered the suction process.

According to a second aspect of the present invention, in the engine of the first aspect, a cam shaft that rotates in conjunction with a crankshaft is provided with a cam that controls opening and closing of the intake gas moving valve so that movement of the cam in the axial direction is adjustable. The contour of the cam is gradually changed in the axial direction of the cam shaft so that the opening angle of the intake gas moving valve changes when the cam is displaced in the axial direction.

[0008]

In the above engine, when one cylinder enters the compression process, the other cylinder enters the intake process. The intake gas transfer valve of the one cylinder is opened in the initial stage of the compression process of the cylinder, and the intake gas transfer valve of the other cylinder is opened in the initial stage of the intake process of the other cylinder. A part of the intake gas in the cylinder moves into the other cylinder through the ventilation duct. Therefore, in the one cylinder, the intake gas amount can be substantially reduced, and the intake amount / exhaust amount ratio (intake amount / exhaust amount) can be reduced. In this case, a part of the intake gas discharged from the one cylinder in the compression process is smoothly discharged to the ventilation duct, unlike the method of backflowing in the direction of the carburetor, and passes through the ventilation duct to the inside of the other cylinder. To move smoothly. Therefore, it is possible to secure a smooth gas flow at the intake valve position.

In claim 2, when the cam is displaced in the axial direction, the contour of the cam changes, and the opening angle of the intake gas moving valve gradually changes. This makes it easy to set the optimum intake / exhaust volume ratio. Here, the opening angle includes both the opening angle and the closing angle. However, normally, the opening angle is made constant, for example, the crank angle is 0 °, and the closing angle is made variable.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1A is a cross-sectional view schematically showing an engine according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along the line AA of a main part of FIG. The illustrated engine 1 is a four-cylinder engine having four cylinders 2. In the figure, 3 is a piston, 4 is a crankshaft, 5 is an intake port, 6 is an exhaust port, 7 is an intake valve, and 8 is an exhaust valve. Although the above-mentioned configuration is a general configuration, in the present invention, an intake gas moving opening 11 is newly provided in the cylinder head 2a portion of each cylinder 2, and the intake gas moving opening 11 is communicated with each other. A duct 12 is provided, and the intake gas moving opening 1 of each cylinder 2 is provided.
1 is provided with a suction gas moving valve 13 for opening and closing the suction gas moving opening 11. The ventilation duct 12 only communicates with the four cylinders 2 and has no opening to the outside. And each intake gas moving valve 13
The cam 15 described later interlocks with the crankshaft so that a part of the intake gas in one cylinder 2 is discharged to the ventilation duct 12 at the beginning of the compression process and moves to another cylinder 2 that has entered the intake process. It is designed to be opened and closed. The intake valve 7 and the exhaust valve 8 are not shown in FIG. Also, FIG.
The illustration of the spark plug is omitted in both (a) and (b).

The operation of the engine 1 will be described below.
The two cylinders 2 are as shown in FIG.
Gas is sucked from the intake port in the intake stroke at a crank angle of 0 ° to 180 °, but the intake gas moving valve 13 opens at the timing of 0 ° in this intake stroke (at this time, the intake gas in the other cylinder is sucked in). The gas flows in from the gas moving valve 13, which will be described later). Intake gas transfer valve 1
3 continues to open as it is, and the initial period in the subsequent compression process of 180 ° to 360 °, that is, 180 ° to θ ° (θ
° = 180 ° + α, for example 240 ° or 270 °
Etc.), the discharging process specific to the present invention is performed. That is, the intake gas moving valve 13 remains open even if it exceeds 180 ° and closes at θ °, but during that period (180
(Between ° and θ °), a part of the inhaled gas is pushed out (exhausted) to the ventilation duct 12. Thus, a part of the intake gas in the cylinder that has entered the compression process is pushed out to the ventilation duct, which is called “exhaust”. Continued θ ° ~ 360
The area between ° is the original compression process. Then, the expansion process (3
60 ° to 540 °), exhaust process (540 ° to 720 °)
Then, the above suction process, discharge / compression process, expansion process, and exhaust process are repeated.

Although one cylinder 2 is as described above, the overall operation of the four cylinders 2 will be described with reference to FIGS. 3 and 4 show the ignition order (expansion order) of the four cylinders 2 by the cylinder number: 1, 3, 4, 2
This is the case when Each of the figures 1 to 3 shown in FIG. 3 shows the initial state in each step, and in FIG. 3, the intake gas movement of the second cylinder that has entered the compression step and the first cylinder that has entered the intake step. Valve 13
Is open, and the intake gas moving valves 13 of the third and fourth cylinders are closed. Therefore, as shown by the arrow, part of the intake gas in the second cylinder is discharged to the ventilation duct 12 and moved into the first cylinder. Therefore, in the first cylinder, the intake gas amount is substantially reduced, and the intake amount / exhaust amount ratio (intake amount / exhaust amount) is reduced. The movement of the suction gas in this case is smooth, and the hammer phenomenon due to the collision of the gas does not occur at the suction valve position unlike in the system in which the gas flows backward in the direction of the carburetor. Subsequently, each cylinder 2 advances its respective process and enters the next process.

In the step (1), part of the suction gas in the first cylinder that has entered the compression step is moved into the third cylinder that has entered the suction step, as in the above. In the next step,
Part of the suction gas in the third cylinder that has entered the compression process is moved into the fourth cylinder that has entered the suction process. In the next step, part of the suction gas in the fourth cylinder that has entered the compression step is moved into the second cylinder that has entered the suction step. The above steps are repeated.

FIG. 4 is a diagram showing the above description by the crank angle-piston position diagram of four cylinders.
In this figure, the intake, discharge / compression, expansion, and exhaust steps are shifted by 180 ° in the order of the first cylinder, the third cylinder, the fourth cylinder, and the second cylinder. The timing at which the intake gas of the cylinder that has entered the process) moves to the cylinder side that has entered the intake process is shown. In FIG. 3, each stage of ,, is a part indicated by the same symbol ,,, in FIG.

In the above, the intake gas moving valve 13
Opens at the timing of 0 ° in the intake process and closes at the timing of θ ° after entering the compression process. This closing angle θ ° is the optimum intake amount / exhaust that can maximize the energy efficiency of combustion gas. Set so that the ratio becomes quantitative. For example,
If the closing angle is set to θ ° = 240 °, it will be opened during the initial 60 ° in the compression process, and the respective discharge amount (discharge amount to ventilation duct: discharge volume by piston) is the cylinder discharge amount. It becomes 1/4 of that. Further, if the closing angle θ ° = 270 ° is set, an additional 90 ° is opened in the initial stage of the compression process, and the discharge amount becomes half of the cylinder exhaust amount.

In the above description, the intake process means a process in which the crank angle is between 0 ° and 180 ° (between the top dead center and the bottom dead center of the piston), and the intake valve is opened. It does not mean the period of time. Therefore, the present invention does not limit the opening / closing timing of the intake valve itself. For example, the present invention can be applied to a case where the opening timing of the intake valve is set earlier than the crank angle of 0 °. In this case, the intake gas moving valve 13 may be opened at a timing of 0 ° without adjusting to the intake valve, or may be opened at a timing corresponding to the intake valve. Further, the same applies to the closing timing of the intake valve. For example, in the conventional engine shown in FIG. 8 in which the closing timing of the intake valve is delayed to an initial fixed angle in the compression process, the intake gas moving valve of the present invention is provided. It does not exclude things. However, in this case, the problem with a part of the intake gas flowing back toward the carburetor is
Even if it is reduced, it will remain slightly.

Next, an embodiment of a cam for controlling the opening / closing of the intake gas moving valve 13 will be described with reference to FIGS. The cam 15 shown in FIG. 5 and FIG. 6 has a cylindrical movable shaft 17 which is movable in the axial direction of the cam shaft 16 which rotates in conjunction with the crankshaft (however, one rotation by two rotations of the crankshaft). The cam 15 is fixed to the movable shaft 17, and the contour of the cam 15 is shown in FIG.
As shown in the (b) cam development view, the intake gas moving valve 13 is gradually changed in the axial direction so that the closing angle of the valve 13 changes. In FIG. 6, the opening position is indicated by a and the closing position is indicated by b. The opening position a of the cam 15 is 0 °
Constant at 0 ° (crank angle is also 0 °), the closing position b is the cam rotation angle θ ° / 2 ° (crank angle θ °: θ ° = 180 °
+ Any angle)). Further, the cam shaft 16 for the intake gas moving valve 13 may be provided separately from the cam shaft for the intake / exhaust valve, but if the cam shaft for the intake / exhaust valve can be used, it may be naturally used. .

In the above, the intake gas moving valve 13
If you want to change the closing angle of the cam, shift the cam 15 in the axial direction to move the cam 1 at the position of the intake gas moving valve 13.
The contour of 5 changes and the closing angle changes. This gives
The optimal intake / exhaust volume ratio can be easily set.

Although the embodiment has been described with reference to a four-cylinder engine, it can be applied to an engine with six or more cylinders. In an engine with 6 or more cylinders, the gas moving in the ventilation duct flows into the next or subsequent cylinders at the maximum suction speed, so further improvement in efficiency can be expected.

Further, although the above embodiment has been described assuming a gasoline engine, the present invention can be applied to a diesel engine.

[0021]

According to the present invention, the intake gas moving valve is provided at the cylinder head portion of each cylinder of the engine, and a part of the intake gas in one cylinder is discharged at the beginning of the compression process. Since it is moved to another cylinder that has entered, it is possible to reduce the intake amount / exhaust amount ratio (intake amount / exhaust amount), and at the same time, smooth gas flow at the intake valve position. It became possible to secure. As a result, the intake / exhaust volume ratio can be reduced to prevent knocking due to overcompression, and at the same time as in a conventional engine in which part of the intake gas flows back toward the carburetor, the intake gas and exhaust gas are separated. The drawback that the efficiency of the carburetor and supercharger was reduced due to the hammer phenomenon due to collision was solved.

According to the second aspect, the opening angle of the intake gas moving valve can be adjusted by adjusting the movement of the cam in the axial direction of the cam shaft, so that the energy efficiency of the combustion gas can be effectively used. It is possible to easily realize setting of the optimum intake amount / exhaust amount ratio.

[Brief description of the drawings]

FIG. 1 schematically shows an engine according to an embodiment of the present invention, (a) is a cross-sectional view of the engine, and (b) is (a).
3 is a cross-sectional view taken along the line AA of the main part of FIG.

FIG. 2 is an explanatory view schematically showing a process for one cylinder in the above engine.

FIG. 3 is a view for explaining the operation of the present invention in the above engine by opening and closing the intake gas moving valves of the four cylinders, and the process proceeds in the order of.

FIG. 4 is a diagram for explaining the operation of the present invention in the above engine by the crank angles of four cylinders. The parts of ,,, in FIG. 4 are, respectively, in FIG.
It corresponds to the time point of.

FIG. 5 is a perspective view showing an embodiment of a cam for adjusting the opening angle of the intake gas moving valve in the engine of claim 2;

6A and 6B are development views of the cam of FIG. 5, in which FIG. 6A is a developed plan view and FIG. 6B is a sectional view taken along line BB of FIG.

FIG. 7 is an explanatory view schematically showing the steps of a conventional general engine.

FIG. 8 is an explanatory view schematically showing a process of another conventional engine.

[Explanation of symbols]

 1 Engine 2 Cylinder 2a Cylinder Head 3 Piston 4 Crank 5 Intake Port 6 Exhaust Port 7 Intake Valve 8 Exhaust Valve 11 Intake Gas Movement Opening 12 Vent Duct 13 Intake Gas Movement Valve 15 Cam 16 Cam Shaft θ ° Intake Gas Movement Valve Closing angle of

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[Procedure amendment]

[Submission date] July 6, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

Although one cylinder 2 is as described above, the overall operation of the four cylinders 2 will be described with reference to FIGS. 3 and 4 show the ignition order (expansion order) of the four cylinders 2 by the cylinder number: 1, 3, 4, 2
This is the case when Each of the figures 1 to 3 shown in FIG. 3 shows the initial state in each step, and in FIG. 3, the intake gas movement of the second cylinder that has entered the compression step and the first cylinder that has entered the intake step. Valve 13
Is open, and the intake gas moving valves 13 of the third and fourth cylinders are closed. Therefore, as shown by the arrow, part of the intake gas in the second cylinder is discharged to the ventilation duct 12 and moved into the first cylinder. Therefore, in the second cylinder , the intake gas amount is substantially reduced, and the intake amount / exhaust amount ratio (intake amount / exhaust amount) is reduced. The movement of the suction gas in this case is smooth, and the hammer phenomenon due to the collision of the gas does not occur at the suction valve position unlike in the system in which the gas flows backward in the direction of the carburetor. Subsequently, each cylinder 2 advances its respective process and enters the next process.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction contents]

Next, an embodiment of a cam for controlling the opening / closing of the intake gas moving valve 13 will be described with reference to FIGS. The cam 15 shown in FIG. 5 and FIG. 6 has a cylindrical movable shaft 17 which is movable in the axial direction of the cam shaft 16 which rotates in conjunction with the crankshaft (however, one rotation by two rotations of the crankshaft). The cam 15 is fixed to the movable shaft 17, and the contour of the cam 15 is shown in FIG.
As shown in the (b) cam development view, the intake gas moving valve 13 is gradually changed in the axial direction so that the closing angle of the valve 13 changes. In FIG. 6, the opening position is indicated by a and the closing position is indicated by b. The opening position a of the cam 15 is 0 °
Constant at 0 ° (crank angle is also 0 °), the closing position b is cam rotation angle θ ° / 2 (crank angle θ °: θ ° = 180 ° +
Any angle)). In addition, the intake gas transfer valve 1
The cam shaft 16 for 3 may be provided separately from the cam shaft for the intake / exhaust valve, but if the cam shaft for the intake / exhaust valve can be used, naturally it may be used.

Claims (2)

[Claims] 1. In a four-step engine having a plurality of cylinders, each cylinder head portion of each cylinder is provided with an intake gas moving opening, and a ventilation duct is provided to connect the intake gas moving openings to each other. And a suction gas moving valve for opening and closing the suction gas moving opening,
Each of the intake gas moving valves is controlled to be opened and closed so that a part of the intake gas in one cylinder is discharged to the ventilation duct at the beginning of the compression process and moved to another cylinder that has entered the intake process. An engine characterized by that. 2. A cam shaft, which rotates in conjunction with a crankshaft, is provided with a cam for controlling the opening / closing of the intake gas moving valve so that the cam can be moved and adjusted in the axial direction, and the contour of the cam is 2. The engine according to claim 1, wherein the camshaft is gradually changed in the axial direction so that the opening angle of the intake gas moving valve changes when the camshaft is displaced in the axial direction.