JPH01290919A - Four-cycle internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce fuel consumption by making the valve opening lift of an intake valve variable and cutting off one direction of a head portion surrounding a valve seat. CONSTITUTION:A mechanism for making the valve opening lift of an intake valve 1 variable is provided. One direction of a cylinder head portion surrounding a valve seat is cut off to form a guide groove 4. At the time of low load, the valve opening lift is restricted to generate a directional property and turbulence in new air flowing into a cylinder by means of the guide groove 4. Thereby, combustion at the time of low load can be improved reducing fuel consumption.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to combustion gagging technology for internal combustion engines.

(Prior art) In order to increase the thermal efficiency of an internal combustion engine and at the same time reduce harmful components in the exhaust gas, the technical challenge is how to effectively burn the fuel supplied in the combustion chamber within an extremely short period of time. Many studies are being conducted on the subject.

In premix combustion engines, which are mainly used as automobile engines, combustion, especially at low loads, is caused by a reduction in the compression start pressure φ temperature, etc. due to the throttling action of the supply air, and in relation to the previous cycle residual gas ratio. tends to be slow, which is a cause of a decrease in thermal efficiency.

Increasing the compression ratio is said to be effective as a countermeasure against this problem, but increasing the compression ratio conversely causes excessive end gas knocking in the high-load range, which limits the compression ratio, resulting in the maximum thermal efficiency of this type of engine. is currently stagnant at around 30%.

Furthermore, although it is known that the cause of excessive knocking that impedes a high compression ratio is the self-ignition of the end gas, it is also important to note that when the engine is at low load, that is, when the intake air amount is small, the combustion chamber It is known that it is effective to create turbulence in the air-fuel mixture and combustion process, and that it is possible to improve combustion by reducing the valve opening lift at partial load and creating turbulence. No practical examples have been announced yet.

(Problems to be Solved by the Invention) The present invention solves problems that have been required in the past but have been difficult to achieve, namely, generating a strong swirl flow in the combustion chamber during partial load of an engine with a small amount of air supply, and The objective is to present a technology that can supply a large amount of air with little swirl into the combustion chamber under load, and another purpose is to present a technology that controls end gas knocking by forming an air layer at the end of the combustion chamber. It is something to do.

(Means for Solving the Problems) The present invention is capable of providing constant feed during partial loading by varying the opening/closing lift of the intake valve according to the load and by configuring a guide groove in the vicinity of the cylinder head valve seat. When the amount of air is small and the combustion chamber is required to have a swirl or a gap, the valve opening gap is reduced, which causes the fresh air to flow into the cylinder in a directional manner and causes turbulence. In this method, a large amount of fresh air can flow by increasing the opening time of the valve to eliminate the directional effect of the guide groove and reduce the inflow resistance.

(Example) An example of the present invention will be explained with reference to the figures as follows.◎ In Figures (1), (6), (E) and (0), the intake valve
) has a valve seat (6) built a little inside the cylinder head (21), and an intake flow guide groove (4) is formed in the head that surrounds the valve seat. In addition, the rocker arm of the cylinder head is constructed with an O-lift variable mechanism as shown in Fig. 2 so that the valve lift can be varied during operation, and about 5 m from arrow (5) is located at the movable fulcrum [X The amount of lift of the intake valve can be varied by changing the amount of intake valve according to the demands of engine load, rotation speed, etc. ◇With this mechanism, the valve lift is limited to a small amount when the engine is under low load, so that the amount of intake valve lift is reduced. Even if the fresh air is small, it flows into the cylinder mainly through the guide groove (4) with speed, turbulence, and directionality.

The direction of the guide groove (4) is determined in advance as shown in (6) in order to generate a swirling flow inside the cylinder, and the swirling flow that occurs continues through the compression stroke and continues until combustion due to the law of conservation of motion. This contributes to shortening the combustion period. In addition, when the engine is under high load and requires a large amount of air, the intake valve lift is increased to reduce inflow resistance and increase the flow of fresh air.In this case, the influence of the guide groove is attenuated. There is no strong air flow inside the cylinder. Also,
The valve lift can be varied by moving the fulcrum X by sliding or rotating a cam (as shown in Figure (2)), but Figure (2) shows an example of the variable mechanism. It is clear that the purpose of the present invention can be achieved by using other methods such as a valve lift variable mechanism, and the valve lift can be varied mechanically or electrically depending on the load and rotational speed requirements. It is also possible to operate it according to the requirements and control it electronically.

(Effects of the Invention) As described above, in the present invention, when the engine is under high load, the valve oscillation is maximized to eliminate the resistance of the inflow air passage, eliminate swirl, and improve the volumetric efficiency, and when the engine is under low load, This is intended to reduce fuel consumption by limiting the amount of valve gas and generating swirl and turbulence to improve combustion in the partial load range, thereby improving the engine's specific output and greatly reducing fuel consumption in the partial load range. It also reduces harmful components in the exhaust gas, bringing about effects such as vines.

In addition, if the configuration of the present invention is arranged so as to form an air swirl in the peripheral wall area of the combustion chamber with a directional air supply valve (as shown in Figure 9), it can also be used in a premix engine. Since fuel particles at the end can be removed or diluted, excessive knocking due to end gas will not occur, and the effective compression ratio of the engine can be increased.

Therefore, the effect of improving engine thermal efficiency can be obtained. Further, by applying the present invention to a variable timing system to change the intake/exhaust phase and perform an overlapping action, it is possible to reduce the membrane loss and thereby reduce fuel consumption. Promoting turbulence through multiple guide grooves and metamorphism was also effective in promoting combustion.

[Brief explanation of the drawing]

Figure (1) is an explanatory cross-sectional view of the intake valve and its surroundings showing the structural action of the present invention, and (4) is a diagram showing the closed state of the intake valve (aS) when the valve-opening gap is controlled; (II shows an example of a cutting part. Figure (2) is a schematic configuration diagram showing an example of a seven-point variable mechanism for opening a valve, and Figure (3) is a diagram showing an example of a variable valve opening mechanism. It is a layout diagram showing an example of the position and guide groove of an air supply valve attached to the cylinder head. In the figure, (1)...intake valve, (2)...inner surface of the cylinder head, (S-...・Valve seat, (4)--Guide groove (notched part), (5)--Fullin cam, (6)--Direction of guide groove, (Sword, (8)--Air supply valve, (q )・−exhaust valve, (
10) - Ignition machine, x...Fully point, X'...Moved fulcrum O Fig. 1 Fig. 2 Fig. 5 (4) (7)

Claims (4)

[Claims] (1) In an internal combustion engine that has a mechanism that can vary the opening gap of the intake valve or intake/exhaust valve, the intake valve seat is installed at an internal position from the normal position, and the head part that surrounds this valve seat is By adopting a structure with a notch in one direction, when the valve opening lift is small, the fresh air flowing into the cylinder is mainly transferred from the notch to a flow with directionality, speed, turbulence, and swirl. An internal combustion engine characterized by being powered internally. (2) A four-stroke internal combustion engine equipped with a variable valve opening lift mechanism, which is characterized by reducing the exhaust valve lift to vary the amount of residual gas in the cylinder, thereby improving the internal EGR effect during combustion. . (3) The four-stroke internal combustion engine according to claim (1), which has a variable intake/exhaust timing mechanism. (4) The four-stroke internal combustion engine according to claim (1), characterized in that the air supply valve is provided in an area outside of a normal intake/exhaust valve.