JPS6143522B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an engine scavenging and exhaust control device.

For example, in a scavenging engine where air flows into a cylinder through a scavenging hole and combustion gas in the cylinder is exhausted through an exhaust hole or exhaust valve,
Conventionally, as a means to improve the thermal efficiency of the engine,
It is widely known that the expansion work within the cylinder is increased by delaying the exhaust start timing. That is,
Figure 1 shows a pressure chart near the bottom dead center of the scavenging engine, and it shows that the indicated mean effective pressure is increased by delaying the exhaust start timing compared to the normal case. Explaining.

However, if the exhaust start time is delayed, in the case where the scavenging hole is normally opened and closed at the top of the piston, the gas pressure in the cylinder is still high when the scavenging hole is open, and combustion gas flows back from the cylinder into the scavenging chamber. There is a risk that various problems may occur.
In addition, engines with exhaust holes in the cylinder liner have the problem that if the exhaust hole is opened and closed at the top of the piston as usual, it is extremely difficult to delay the start of exhaust. .

SUMMARY OF THE INVENTION Therefore, the present invention aims to solve the above-mentioned problems by opening and closing scavenging holes or exhaust holes at desired times regardless of the movement of the piston, thereby significantly improving the thermal efficiency of the engine. .

Therefore, in the present invention, the outer surface of each scavenging hole portion or each exhaust hole portion is formed into a concave surface, so that the outer surface of each scavenging hole portion or each exhaust hole portion is rotatable in close contact with each concave surface, and the communication between the scavenging hole or exhaust hole and the outside of the cylinder liner is cut off. A valve body having a seal wall is arranged separately, and a small gear meshing with a ring-shaped large gear rotatably fitted around the cylinder liner is provided so as to be rotatable integrally with each valve body, The valve body is opened and closed by rotation of the large gear.

Hereinafter, one embodiment of the present invention will be described based on the drawings. In FIGS. 2 to 6, reference numeral 1 indicates a scavenging hole (or scavenging hole). In the annular member 3, a cylindrical concave surface 3 is provided around the external opening of each scavenging hole 1.
a is formed.

Reference numeral 4 denotes a scavenging control valve disposed for each scavenging hole 1, which has upper and lower rotating shafts 5 and 6, and has a concave surface 3a.
A seal wall 7 that is rotatable in close contact with the scavenging hole 1 and cuts off communication between the scavenging hole 1 and the outside of the cylinder liner 2.
A cylindrical valve body 9 having air holes 8 formed therein, and ball bearings 10 and 11 that are fitted onto the rotating shafts 5 and 6 are fitted inside and fixed to the outer periphery of the cylinder liner 2. A pair of upper and lower bearing parts 1
It consists of 2 and 13.

A ring-shaped large gear 14 is rotatably fitted on the outer periphery of the cylinder liner 2.
4 has a small gear 1 fixed to the lower part of each rotating shaft 6.
5 are engaged with each other. FIG. 6 shows the drive mechanism of the large gear 14. That is, 1
6 is a drive arm fixed to the large gear 14;
It is driven back and forth by a hydraulic cylinder device 18 attached to the engine body 17.

In the above configuration, when the gas is expanding within the cylinder liner 2, the scavenging hole (or exhaust hole) 1 is closed by the seal wall 7A, as shown in FIGS. 4 and 5. Now, at a predetermined opening timing, the large gear 14 is rotated by a predetermined angle using the hydraulic cylinder device 18, and the valve body 9 is rotated as shown in FIGS. 2 and 3 to open the scavenging hole 1 and the ventilation hole 8. If these are communicated with each other, the scavenging hole 1 will be in an open state and scavenging air will be carried out into the cylinder liner 2. When closing the scavenging hole (or exhaust hole) 1 at a predetermined time, the hydraulic cylinder device 18 is operated in the opposite manner to the above to rotate the large gear 14 back to its original position, as shown in FIGS. 4 and 5. As shown, the scavenging control valve 4 may be closed again. Alternatively, while the ventilation hole 8 and the scavenging hole 1 are kept in communication, the scavenging hole 1 is closed by the piston itself based on the movement of the piston of the engine like in a normal scavenging type engine, and then the hydraulic cylinder is closed at an appropriate time. The scavenging control valve 4 is operated by operating the device 18.
may be in a closed state.

It should be noted that a structure having only one seal wall 7A or 7B can function satisfactorily, but the structure shown in the figure is less likely to deform due to pressure inside the cylinder, and for example, if the seal wall 7A is worn out, the seal This means that wall 7B can be used. Also, the drive arm 1 for the large gear 14
By changing the fixing position of valve body 6, the sealing walls of all valve bodies 9 can also be updated. Furthermore, by appropriately adjusting the operating stroke of the hydraulic cylinder device 18 and its control method, the seal wall 7A
The seal walls 7A and 7B may be brought into contact with the concave surface 3a alternately, and the seal walls 7A and 7B may be brought into contact with the concave surface 3a alternately.
may alternately contact the concave surface 3a.

Further, in the above embodiment, the valve body 9 is cylindrical, but the concave surface 3a may be a spherical recessed part, the valve body 9 may be a sphere having a rotation axis, or it may be shaped like a rotating body. It can be of any shape. Further, in the above embodiment, a concave surface 3a is formed on the annular member 3 attached to the outer circumferential surface of the cylinder liner 2. It may be formed on a plate attached to the outer surface of the cylinder liner 2, or it may be formed directly on the outer surface of the cylinder liner 2.

In addition, in the above embodiment, the cylinder gas pressure acting on the valve body 9 is controlled by the ball bearings 10, 11.
Therefore, the rotational driving force of the valve body 9 only needs to be small, and a drive source such as the hydraulic cylinder device 18 with a small capacity can be sufficiently effective.

As described above, according to the present invention, the scavenging hole or the exhaust hole can be opened and closed at any time without being restricted by the movement of the piston, and the exhaust start time can be delayed as much as possible, so that the engine Thermal efficiency has been greatly improved, and since each valve body is opened and closed at once by the rotation of a large gear, it is possible to improve thermal efficiency even though a valve body is provided for each scavenging hole or exhaust hole. The number of drive devices can be reduced, and all valve bodies can be easily synchronized.

[Brief explanation of the drawing]

Fig. 1 is a diagram illustrating an acupressure diagram near the bottom dead center of a scavenging engine, and Figs. 2 to 6 are diagrams illustrating an embodiment of the present invention, with Fig. 2 showing an open state. 3 is a sectional view thereof, FIG. 4 is a view showing the closed state, FIG. 5 is a sectional view thereof, and FIG. 6 is a sectional view of FIG. 5. 1... Scavenging hole (or exhaust hole), 2... Cylinder liner, 3a... Concave surface, 7A, 7B... Seal wall, 9... Valve body, 14... Large gear, 15... Small gear.

Claims (1)

[Claims] 1. In an engine that has a scavenging hole and an exhaust hole in the cylinder liner, or an engine that has an exhaust valve and a scavenging hole in the cylinder liner, a concave surface is formed around the external opening of each scavenging hole or each exhaust port, and a concave surface is formed around the external opening of each scavenging hole or each exhaust port, and The cylinder liner is provided with a valve body that is rotatable and rotatable around the cylinder liner, and has a seal wall that cuts off communication between the scavenging hole or the exhaust hole and the outside of the cylinder liner, and is rotatably fitted around the cylinder liner. A scavenging/exhaust control device characterized in that a small gear meshing with a ring-shaped large gear is provided so as to be rotatable together with each valve body, and the valve body is opened and closed by rotation of the large gear.