JPS59173511A - Valve mechanism of internal-combustion engine - Google Patents

Abstract

PURPOSE:To reduce pressure loss at gas passage as well as improve filling efficiency by providing an intake vent and/or exhaust vent closed near a piston lower dead point in a cylinder wall in an internal-combustion engine equipped with a regenerating heat exchanger 34 inside a combustion chamber. CONSTITUTION:A heat regenerating internal-combustion engine is constructed such that a regenerating heat exchanger 34 is arranged in a combustion chamber 30, and this regenerating heat exchanger 34 is held and fixed between a cylinder head 29 and a cylinder 24. And, an intake 27 and an exhaust vent 27a are formed at a symmetrical position with respect to the center of the cylinder 24 on the peripheral wall upper end part of the cylinder 24. Further, the wall thickness of an intake and exhaust bents 27, 27a forming part of the cylinder 24 is made thicker, and a guide groove 26 extending in the cylinder center axis so as to traverse said intake and exhaust vents 27, 27a is formed on said part. Further, a valve 1 provided with a passage 4 is fitted in said guide groove 26, and the valve 1 is opened and closed by a cam 2 synchronized with engine rotation via a roller 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a valve mechanism for an internal combustion engine equipped with a regenerative heat exchanger and the like.

The filling efficiency in the intake stroke of an internal combustion engine is about 0.65 to 0.8 in a gasoline engine even when the throttle valve is fully open, and about 0.8 to 0.9 in a diesel engine. The reason why the filling efficiency of gasoline engines is lower than that of diesel engines can be said to be due to the resistance in the part that adjusts the throttle of the carburetor. Since it is constricted, the pressure drop due to pressure loss has an effect. This pressure drop increases to 0.12-0.26 when equipped with a turbocharger.

In order to increase the filling efficiency in the intake stroke, it is necessary to reduce the pressure loss due to the restriction of the intake valve and exhaust valve. For this purpose, the cross-sectional area of the air passage when the valve is open must be increased. On the other hand, in the case of a heat regenerative internal combustion engine equipped with a regenerative heat exchanger inside the combustion chamber, in order to increase the efficiency of the regenerative heat exchanger, heat regeneration is applied to the intake air before combustion, and to the combustion gas after combustion. Heat storage must be performed by each heat exchanger.

However, in the general overhead valve type, in which intake and exhaust valves are installed in the cylinder head, there is a limit to the passage area.

Furthermore, placing the intake valve in the cylinder head that is directly connected to the combustion chamber under high temperature will heat the intake air and create a high pressure (which will prevent the intake air from continuing to flow into the combustion chamber). In order for the regenerative heat exchanger to effectively store and regenerate the heat of the combustion gas, it is necessary to install a cold chamber in a part away from the combustion chamber, that is, on the opposite side of the combustion chamber separated by the regeneration heat exchanger. It is preferable to provide the intake valve and exhaust valve on the side, but if the conventional side valve type valve mechanism is placed directly in the center of the side wall of the cylinder, the compression ratio will be lower due to the large dead space occupied by the regenerative heat exchanger. It is virtually impossible to take a large amount.

The purpose of the present invention is to increase the compression ratio as much as possible for engines with large dead space, such as 4-cycle heat regeneration internal combustion engines.
Moreover, it is an object of the present invention to provide a valve mechanism for an internal combustion engine with high charging efficiency.

For this reason, the configuration of the present invention is such that at least one of an intake port and an exhaust port that are closed near the bottom dead center of the piston is provided on the wall of the cylinder, and a valve that opens and closes at least one of the intake port and the exhaust port opens and closes the passage. and is configured to move in the direction of the central axis of the cylinder along the outer wall of the cylinder in relation to the rotation of the engine.

The present invention will be described with reference to an embodiment in the case of a thermal regeneration type internal combustion engine. As shown in FIG. 1, the regenerative internal combustion engine includes a cylinder 24 into which a piston 15 is fitted. A crank shirt 1-21 is rotatably supported by a crank case 22 connected to an end of this cylinder 24, and this arm 2
Connecting rod 18 with bottle 19 at the tip of
is connected at one end, while the other end is connected to the piston 15 with a pin 17. The piston 15 has a cylinder 24
A plurality of piston rings 16 are attached to ensure airtightness of the fitting portion.

In order to arrange the regenerative heat exchanger 34 inside the combustion seedling 30, a cylinder head 29 for closing the cylinder 24 is connected to the end of the cylinder 24, and the cylinder head 29 and the cylinder 2
A heat exchanger 34 is fixed between the flange and the flange. A fuel injection nozzle 33 is attached to the center of the cylinder head 29. A jacket 23 is provided on the wall of the cylinder 24 to introduce cooling water.

The valve mechanism according to the invention is constructed as follows.

An intake port 27 and an exhaust port 27 are located at the upper end of the peripheral wall of the cylinder 24 on opposite sides with respect to the center of the cylinder 24.
a is provided. The wall thickness of the cylinder 24 is increased at the portions where the intake port 27 and the exhaust port 27a are provided, and a guide groove 26 is provided which extends in the central axis direction of the cylinder so as to traverse these portions. The valve 1, which is biased upward by the spring 3, is fitted into the guide groove 26.

A roller 8 is supported at the upper end of the valve 1 with a bottle 10 and is urged into engagement with the cam 2. This cam 2 is cover 3
This camshaft is supported by the two cylinder heads and is driven by the crankshaft 21 at a speed of 172. The cross-sectional shape of the guide groove 26 and the valve 1 fitted therein is approximately rectangular to prevent the valve 1 from rotating, and an intake port 27 and an exhaust port 27a are provided in the intermediate portion thereof.
A passage 4 is provided for opening and closing the respective passages.

As shown in FIG. 2, the cross-sectional shape of the valve 1 is such that the wall surface 1a adjacent to the inner circumferential surface of the cylinder 24 is arcuate. Then, as shown in FIG. 3.4, a curved seal 5 and a straight vertical seal 5a are attached to the wall surface 1a so as to surround the passage 4. For this purpose, a groove 7 is provided in the curved wall surface 1a of the valve 1, into which a wave-shaped spring 6 and a seal 5 are fitted, and the outer surface of the seal 5 is pushed out from the groove 7. , is pressed against the curved wall surface 26a of the guide groove 26. The material of the seal 5 is the same as that of a known piston ring. As shown in FIG. 5, the valve 1 has a box-shaped cavity at its lower end that guides and supports the ends of a pair of springs 3, and has a pair of brackets 13 at its upper end so as to be horizontal. A bottle 10 is supported, and a roller 8 is rotatably supported via a bush 9.

In the embodiment shown in FIG. 6.7, the cross-sectional shape of the guide groove 26 and the valve 1 supported thereby is approximately half-moon. And Shi J? Arc-shaped wall surface 1 adjacent to the inner circumferential surface of the conductor 24
a is provided with a groove 7 surrounding a passage 4 having a roughly rectangular cross section, in which a corrugated leaf spring 6 and a seal 5.58 are supported, and an inlet 27 and an outlet 27a of the cylinder 24.
It is pressed against the wall surface 26a surrounding the. In this embodiment, the roller 8 is pressed against the cam 2 by one coil spring 3.

Next, to explain the operation of a four-stroke internal combustion engine equipped with the above-mentioned valve mechanism, Fig. 1 shows the end state of the exhaust stroke. Valve 1 is pushed open and piston 1 is pushed open during the intake stroke.
5 is lowered, and fresh outside air is sucked in through the intake port 27.

While the piston 15 is rising again after reaching the bottom dead center, the intake valve 1 closes, and the intake air inside the cylinder 24 enters the combustion chamber 30 through the passage 34a8 of the regenerative heat exchanger 34. It is heated by obtaining heat from the heat exchanger 34. When the piston 15 reaches the top dead center, almost all of the intake air inside the cylinder 24 is sent into the combustion chamber 30.

Before the piston 15 reaches top dead center, fuel is injected from the fuel injection nozzle 33 into the combustion chamber 30, and the ignited and combusted gas is transferred to the regenerative heat exchanger 34 while passing through the passage 34a of the regenerative heat exchanger 34. While storing heat, the piston 15 is pushed down. This expansion process of the combustion gas provides rotational power to the crank shirts i to 21.

When the piston 15 rises again after passing through the bottom dead center, the right valve, that is, the exhaust valve 1, is pushed open by the cam 2, and the combustion gas in the cylinder 24 is discharged to the outside through the exhaust port 27a. At the same time, the left intake valve 1 opens and the same process is repeated.

As described above, the present invention allows the lift of the cam 2 and the width of the passage 4 to be freely set in order to increase the cross-sectional area of the passage 4 of the valve 1. Pressure loss during pumping is small and pump loss can be reduced. This results in higher filling efficiency and improved net thermal efficiency. In particular, if a turbocharger is provided in a heat regeneration type internal combustion engine with the valve mechanism according to the present invention, the thermal efficiency of the internal combustion engine can be improved, and the engine can be made smaller and lighter. Furthermore, since the valve mechanism is disposed on the side of the cylinder, the size of the engine body can be reduced, which also helps improve running stability when used as an engine for automobiles or two-wheeled vehicles.

In the above embodiments, the intake valve and the exhaust valve were explained as the valve mechanism, but the present invention can also be applied to only the intake valve or the exhaust valve to obtain considerable effects. Also, valve 1
The cross-sectional shape perpendicular to the lift direction can be freely determined, such as a rectangle.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an internal combustion engine equipped with a valve mechanism according to the present invention, FIG. 2 is a plan view of the same, FIG. 3 is a horizontal sectional view of the main parts, and FIG. Figure 5 is a perspective view of the same, Figure 6
The figure is a plan view of another embodiment of the valve mechanism, and FIG. 7 is a side view of the same. 1: Valve 2: Cam 3: Spring 4: Passage 5: Seal
6: Leaf spring 7: Groove 8: Roller 10: Pin 15:
Piston 24 Niji cylinder 26: Guide groove 27: Inlet port 27a: Exhaust port 29 Niji cylinder head 33: Fuel injection nozzle 34: Regenerative heat exchanger patent applicant Diesel enclosure 4 Shushiki company agent Patent attorney Toshio Yamamoto

Claims (1)

[Claims] The wall of the cylinder is provided with at least one of an intake port and an exhaust port that are closed near the bottom dead center of the piston. A valve mechanism for an internal combustion engine, characterized in that the valve mechanism is configured to move along the outer wall of the cylinder in the direction of the central axis of the cylinder.