JPH0734913A - Internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce fuel consumption with a simple mechanism by returning intake gas introduced from an intake valve in the initial stage of a compression stroke after an intake stroke. CONSTITUTION:An intake quantity regulating stage of a prescribed angle is provided in the initial stage of a compression stroke after an intake stroke. In this stage, an intake valve 3 is opened in the initial stage of the compression stroke, and the intake gas once taken in is again returned through the intake valve 3 for compressing a little fuel. The closing angle of the intake valve 3 can be changed by the axial movement of a camshaft whose shape has been changed in the axial direction. In such a case where the load of an internal combustion engine is low, by increasing the delay of the closing time of the intake valve 3, fuel consumption can be reduced without rarefying intake gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine that operates in four cycles, such as a reciprocating engine and a rotary engine, and more particularly to a technique for controlling fuel consumption.

[0002]

2. Description of the Related Art In a conventional 4-cycle engine,
In order to reduce fuel consumption and purify exhaust gas, the mixture ratio of the air-fuel mixture supplied from the carburetor is reduced or the fuel supply amount for injection is reduced. By doing so, the air-fuel mixture taken into the cylinder is diluted, so
In order to burn this efficiently and stably, methods such as changing the ignition device, ignition at a plurality of positions, two-stage ignition, and a method of stirring the air-fuel mixture by improving the intake path are adopted.

[0003]

However, in each of the above methods, there is a risk of misfire or the like unless the concentration of the air-fuel mixture is set accurately and the concentration is not made sufficiently uniform. Therefore, in order to ensure the accuracy and uniformity of the concentration of the air-fuel mixture, a precise and complicated intake device is necessary, which inevitably increases the manufacturing cost. Therefore, the present invention has been made in view of the above problems, and an object thereof is to obtain an internal combustion engine that can change the fuel supply amount that is supplied into the cylinder and compressed without changing the concentration of the air-fuel mixture. It is in.

[0004]

Means for Solving the Problems The means taken by the present invention to achieve the above-mentioned object is an intake amount adjusting step for discharging a predetermined amount of a gas sucked in an intake process from an intake valve during a compression process. Is provided. An internal combustion engine provided with a plurality of cylinders that operate in opposite phases to each other, and is configured to be opened during a predetermined period during an intake stroke and a corresponding predetermined period during a compression stroke. Is provided in each cylinder, and the outlet side of the adjusting valve of each cylinder is communicated with each other. In these means, it is desirable to provide crank mechanism moving means for moving the position of the crank mechanism connected to the piston in the sliding direction of the piston.

[0005]

According to such means, since the intake amount adjusting step for discharging the intake air is provided in the compression process subsequent to the intake process, the substantial intake amount of compressed / combusted air can be reduced. Therefore, when fuel consumption is required to be reduced or when the load is low, the intake amount adjustment step can be lengthened to reduce fuel consumption. In this case, since it is not necessary to dilute the concentration of the air-fuel mixture, and the intake amount of the fuel can be adjusted simply by changing the closing angle of the intake valve, a complicated adjusting device is unnecessary. In addition, when adjusting the intake air amount with an adjustment valve that is separate from the intake valve, contamination of the intake system due to backflow of intake air, pulsation, etc. do not occur, and since the air-fuel mixture is exchanged between the cylinders, it is efficient. is there. Also,
Since intake air is exchanged between cylinders in opposite phases, intake resistance and exhaust resistance are reduced, and efficient intake and exhaust can be performed. Furthermore, the compression ratio of the engine can be adjusted to an optimum value by raising and lowering the crankshaft by the crank mechanism moving means, and by adding the crank mechanism moving means to the drive mechanism of the intake valve, the substantial intake amount and compression ratio can be increased. And can be set independently. For example, since it is possible to keep the compression ratio constant even if the intake air amount is reduced,
The combustion state can be stably maintained even if the intake air amount is changed.

[0006]

Embodiments of the internal combustion engine according to the present invention will now be described with reference to the drawings. As shown in FIG. 1, in this embodiment,
This is a four-cycle reciprocating engine in which a piston 2 reciprocates up and down inside a cylinder 1 and an intake valve 3 and an exhaust valve 4 open and close in synchronization with this. In the intake stroke of (a), the piston 2 descends with the intake valve 3 open, and reaches the bottom dead center shown in (b). Then, the piston 2 rises again and enters the compression process, but at the beginning of this process, the intake valve 3 is kept open as shown in (c), and the intake valve 3 is kept open for a predetermined period (for example, the drive cam angle of the intake valve is about 20 to After the lapse of 25 degrees, the intake valve 3 is closed for the first time as shown in (d). After this, as shown in (e), the piston rises to the top dead center and ignites immediately before that, and the combustion gas lowers the piston in the expansion step shown in (f). After that, the exhaust process is continued as in a normal reciprocating engine.

FIG. 2 is a bottom view of the camshaft of the intake valve 3 according to this embodiment. Engagement portions 11 and 12 are formed at both ends of the camshaft 10, and the drive plate 1 having a perforated disc shape is formed therein.
3, 14 are fitted. The drive plates 13 and 14 are screwed onto drive shafts 15 and 16 which are formed as reverse screws. The drive shafts 15 and 16 are connected to mutually meshed gears 17 and 18, and the gear 17 is screwed to an output gear 19a of a motor 19. A pulley (not shown) is attached to the right side of the engaging portion 12, and the camshaft 10 is rotationally driven by a timing belt hung on the pulley.

As shown in FIG. 2B, the camshaft 1
0 has a valve opening angle B corresponding to a larger valve opening section than a valve opening angle A corresponding to a normal valve opening section. The angular difference B−A = X is 0 along the axial direction of the camshaft 10.
It is formed so as to gradually increase from. Therefore, when the drive plates 13 and 14 screwed onto the drive shafts 15 and 16 move by rotating the motor 19, the camshaft 10 moves in the axial direction, and the tappet contact portion (not shown) of the camshaft 10 also moves. The valve opening section during the compression process can be increased or decreased. Actually, the angle difference X
Is set with reference to the optimum intake valve closing angle at which the maximum volume efficiency is obtained in the intake stroke.

In the above-described embodiment, since the intake amount adjusting step for keeping the intake valve open is provided in the compression step subsequent to the intake step, the angle difference X corresponding to the section of that step causes a substantial difference. The amount of intake air can be reduced. Therefore, when the fuel consumption reduction is required or the load is small, the fuel consumption can be reduced by increasing the angle difference X. In this case, since it is not necessary to dilute the concentration of the air-fuel mixture and the intake amount of the fuel can be adjusted only by changing the closing angle of the intake valve, a complicated adjusting device is unnecessary, and the angle difference X is within a predetermined range. If so, a stable combustion state can be maintained. Note that the above-described configuration is not limited to the above-described embodiment, and also in a rotary engine that basically operates in four cycles, the same effect can be obtained by changing or adjusting the shape of the intake port.

FIG. 3 shows an embodiment of the crank mechanism moving means applicable to the above embodiment. A crankshaft 6 is pivotally mounted on a connecting rod 5 pivotally mounted on a piston pin of the piston 2, and a primary output shaft 7 is connected to the crankshaft 6. The gear 7a connected to the primary output shaft 7 is screwed into the gear 8a,
a is a secondary output shaft 8 fixed to a frame (not shown)
Are linked to. On the other hand, the primary output shaft 7 and the secondary output shaft 8 are the arm portion 20 of the planar U-shaped drive member 20.
a and 20b, respectively. The drive member 20 is provided with a partially cylindrical female screw portion that is screwed into a screw rod 22 directly connected to the motor 21, and the drive member 20 rotates in the up-down direction about the secondary output shaft 8 as the screw rod 22 rotates. It is like this. The internal thread portion of the drive member 20 is formed on a saddle-shaped curved surface whose cutting line along a horizontal plane is substantially semicircular and whose cutting line along a vertical surface is an arc shape adapted to the turning radius of the driving member 20. There is.

According to the crank mechanism moving means, the compression ratio of the engine can be adjusted to the optimum value by moving the crank shaft 6 up and down. Further, by adding the crank mechanism moving means to the drive mechanism for the intake valve, the substantial intake amount and the compression ratio can be set independently. For example, the compression ratio can be kept constant even if the intake air amount is reduced.
Therefore, it is possible to increase or decrease only the exhaust amount while keeping the compression ratio and stroke constant, and it is possible to stabilize the combustion state.

FIG. 4 is a reciprocating engine having four in-line cylinders. Each of the cylinders is provided with a regulating valve 30 that is opened at the beginning of the compression process, separately from the intake valve, and the regulating valve 30 of each cylinder is opened and closed. It is connected to the pipe 31. The intake valve 3 and the exhaust valve 4 are driven similarly to a normal engine, and the intake valve 3 opens in the intake process and the exhaust valve 4 opens in the exhaust process.
As shown in (a), when the cylinder is in the early stage of the intake stroke, the adjustment valve 30 is open together with the intake valve 3,
At this time, the adjusting valve 30 is opened even in the cylinder in the intake amount adjusting stage in the initial stage of the compression process. Therefore, the air-fuel mixture sucked into the cylinder flows into the communication pipe 31 through the adjusting valve 30 and flows into the cylinder from the adjusting valve 30 of the cylinder. The adjustment valve 30 of the cylinder is closed in the latter half of the intake stroke, and the adjustment valve 30 of the cylinder in the latter half of the compression stroke is also closed.

In this way, as shown in (b), the air-fuel mixture is exchanged between the cylinders by meeting the adjusting valves. In this example, since the amount of intake air is adjusted by the adjustment valve that is separate from the intake valve, contamination of the intake system and pulsation of intake gas due to backflow of intake air do not occur, and the mixture is exchanged between the cylinders. So it is efficient. Further, as a result of exchanging intake air between the cylinders in opposite phases, intake resistance and exhaust resistance of the air-fuel mixture moving through the adjustment valve and the communication pipe are reduced, and efficient intake and exhaust can be performed through the adjustment valve. it can. In this example, an in-line four-cylinder engine is used, but the same effect can be obtained even if the number of cylinders in which there is a cylinder driven in an opposite phase with respect to each cylinder.

[0014]

As described above, the present invention is characterized by providing the intake amount adjusting step for discharging a predetermined amount of the gas sucked in the intake process during the compression process. Produce an effect. Since the intake amount adjustment stage for discharging intake air is provided in the compression process subsequent to the intake process, it is possible to reduce the substantial intake amount that is compressed and burned. Therefore, when the fuel consumption reduction is required or the load is small, the fuel consumption can be reduced by lengthening the intake air amount adjustment stage. In this case, it is not necessary to dilute the concentration of the air-fuel mixture, and the intake amount of the fuel can be adjusted simply by changing the closing angle of the intake valve or the like, so that a complicated adjusting device is unnecessary. Since the amount of intake air is adjusted by a control valve that is separate from the intake valve, there is no contamination of the intake system or pulsation of intake gas due to backflow of intake air, and it is efficient because the air-fuel mixture is exchanged between the cylinders. . Further, as a result of exchanging intake air between cylinders in opposite phases, intake resistance and exhaust resistance of the regulating valve are reduced, and efficient intake and exhaust can be performed. By moving the crank shaft up and down by the crank mechanism moving means, the compression ratio of the engine can be adjusted to the optimum value. Further, by adding the crank mechanism moving means to the drive mechanism for the intake valve, the substantial intake amount and the compression ratio can be set independently. For example, since the compression ratio can be kept constant even if the intake air amount is reduced, the combustion state can be stably maintained even if the intake air amount is changed.

[Brief description of drawings]

FIG. 1 is a process diagram for explaining the operation of an embodiment of an internal combustion engine according to the present invention.

FIG. 2A is a bottom view showing the structure of the adjustment system of the camshaft in the embodiment, and FIG. 2B is a sectional view of the camshaft.

FIG. 3A is a plan view showing a main part of an embodiment relating to a crank mechanism moving means, and FIG. 3B is a vertical cross-sectional view showing the main part.

FIG. 4A is an explanatory diagram for explaining the operation of a four-cylinder engine equipped with a regulating valve, and FIG. 4B is a process chart of the engine.

[Explanation of symbols]

 1 Cylinder 2 Piston 3 Intake valve 4 Exhaust valve 5 Connecting rod 6 Crankshaft 7 Primary output shaft 8 Secondary output shaft 10 Camshaft 11,12 Engagement part 13,14 Drive plate 15,16,22 Drive shaft 19,21 Motor 20 Drive member 30 Adjustment valve 31 Communication pipe

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location F02D 13/02 L 7536-3G 15/04 A 7536-3G D 7536-3G

Claims (6)

[Claims] 1. In an internal combustion engine operating in four cycles of an intake stroke, a compression stroke, an expansion stroke and an exhaust stroke, a predetermined amount of gas sucked in the intake stroke is discharged from an intake valve during the compression stroke. Internal combustion engine with adjustment stage. 2. The internal combustion engine according to claim 1, wherein the intake air amount adjusting step is within a predetermined section from the beginning of the compression process. 3. The intake valve according to claim 2, wherein the intake valve is driven by an extended cam shaft formed in a shape of which a valve opening section changes in an axial direction, and a drive portion of the extended cam shaft for the intake valve. An internal combustion engine provided with a drive unit moving means for moving in an axial direction. 4. An internal combustion engine having a plurality of cylinders that operate in four cycles of an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke, and operate in mutually opposite phases, and a predetermined period during the intake stroke and corresponding thereto. Each cylinder is provided with a regulating valve configured to be opened during a predetermined period during the compression process,
An internal combustion engine in which the outlet sides of the adjustment valves of each cylinder are in communication with each other. 5. The internal combustion engine according to claim 1, further comprising crank mechanism moving means for moving a position of a crank mechanism connected to the piston in a sliding direction of the piston. 6. The fixed output shaft according to claim 5, wherein a fixed output shaft for transmitting a rotation output from the crank mechanism via a gear train is provided, and the crank mechanism moving means is provided along a peripheral surface of the gear that is interlocked with the fixed output shaft. An internal combustion engine configured to move the crank mechanism.