JPS5815714A - Uniflow-scavenged engine with scavenging control valve - Google Patents

Abstract

PURPOSE:To greatly improve the thermal eficiency of an engine, by providing an annular scavenging control valve slidable on the peripheral surface of the cylinder liner in the circumferential direction, to increase the effective work done by the expanding gas in the cylinder. CONSTITUTION:An annular scavenging control valve 12 is fitted on the part of a cylinder liner 10, which has scavenging ports 3. The valve 12 has through holes 11 at the same circumferential intervals as the scavenging ports 3. The scavenging control valve 12 can slide on the peripheral surface of the cylinder liner 10 in the circumferential direction. According to this constitution, the time of opening of the scavenging ports 3 and exhaust valves can be delayed without reducing the cross-sectional area of each scavenging port. As a result, the effective work in the engine can be increased to greatly improve its thermal efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Uni-70 scavenging type engine having a scavenging control valve on the outer periphery of a scavenging hole portion of a cylinder.

A typical Uni-70 air mold ring (shown in Figure 1)
4) After the engine compression and explosion stroke, the combustion gas flows into the exhaust pipe (6) by opening the exhaust valve (!I).
leaked to. Now, the (1) pV diagram of the engine shown in Figure 1 is, for example, as shown in Figure 2.
As a means to improve thermal efficiency, it is widely known to delay the opening timing of the exhaust valve to increase the tension work of O8l in the cylinder. That is, if part A of FIG. 2 is enlarged to FIG. 3, the exhaust valve opening timing shown by the broken line in the figure is delayed,
In IcFi, the expansion work in the shaded area is increased compared to the normal case shown by the solid line in the figure, and therefore thermal efficiency can be improved. In both FIGS. 2 and 3, the horizontal axis shows the cylinder volume v, and the vertical axis shows the cylinder internal pressure p.

In FIG. 4, the horizontal axis in FIG. 3 is replaced with the crank angle j and is shown as a circle. In other words, the same 1 as in Figure 3! To, *
The line shows the case when the exhaust valve opens normally, and the broken line shows the case when the exhaust valve opening timing is delayed.The area surrounded by the solid line and the broken line corresponds to the increase in expansion work.The dashed line shows the exhaust valve opening timing. If the scavenging hole is opened too late, the cylinder pressure at the time the scavenging hole opens does not drop to the scavenging pressure, and combustion gas flows back from the cylinder to the scavenging chamber, causing various problems. Therefore, in the case of a device that delays the opening timing of the exhaust valve, the practical limit of the opening timing of the exhaust valve is 1 (2), as shown by the solid line, at the point where the pressure inside the scavenging hole becomes less than the scavenging pressure. It turned out to be.

As a means to solve the above-mentioned problems, it may be considered to lower the height of the scavenging hole as shown in FIGS. 5 and 6. That is, as shown in FIG. 5, the planar cross-sectional shape of the scavenging hole (8) for the cylinder (4) K is kept as normal, and
As shown in Fig. 6, which is a view from arrow B, lower the upper part 11 (3 m) of the KJlfi hole (3), and insert the inside of the cylinder (4).
(ri) Ii [ll (2m) cutl [hole (3) f
) Upper #t (3a) t II 9J By delaying the timing of opening, the scavenging hole opening timing is delayed, and accordingly, the exhaust valve opening timing is delayed to increase the expansion work.

However, when the height of the scavenging hole is lowered by lowering the upper edge of the scavenging hole, as shown in FIG. Since the scavenging passage area becomes smaller, the amount of air supplied into the cylinder decreases, which is not effective.

The purpose of the present invention is to easily solve the above-mentioned problems (3) in the pan, increase the effective work by the expanding gas in the cylinder, and significantly improve the thermal efficiency of the rear legs. Then, the annular scavenging air control valve fitted externally to the scavenging air hole part of the sill liner of the Uni-70 sweeping air type machine opening was installed in the circumferential direction KJI.
Illil! When installed in the Fq function, a two-near 0-scavenging type engine is provided which can achieve the above objectives.

An embodiment of the present invention will be described below based on FIGS. 8 to 12. In FIGS. 8 and 10, the cylinder (4
) are penetrated by scavenging holes () at a pitch in the circumferential direction of the cylinder liner. The cylinder liner has through holes (11) with the same circumferential pitch as the scavenging holes (3).
An annular scavenging control valve having a
2) is externally fitted to the outer peripheral surface so as to be movable in the circumferential direction Km. hs is a link attached to the scavenging air control valve, and the bottle (14) K is interlocked and connected to the hydraulic cylinder device. Hydraulic cylinder device (l- is swingably attached to the engine body, and hydraulic oil supply pipe η and hydraulic oil discharge pipe W1ag are respectively connected. (II1.-
are the pulps (4) provided in the middle of each of the above pipes and are opened and closed by the control signal shaft @IK, respectively. This is a compression spring that is disposed at the rear of the piston shaft in the hydraulic cylinder system @aS and is used to push back the piston when the hydraulic oil is discharged through the hydraulic oil discharge pipe IIs. Figure 9 is C- of Figure 8.
The C arrow view, FIG. 11 is the D-D arrow *@ of FIG. 10.

When the exhaust valve is opened after the gas expands in the cylinder (4), the piston e4 in the hydraulic cylinder device is pushed back by the spring (2), as shown in Figures 8 and 9. The scavenging air control valve (II1) is closed. Now, when the predetermined scavenging hole opening timing is reached, the pulp control valve is opened with the palgu closed and the control signal 4 is activated, as shown in Fig. 1θ. The hydraulic cylinder device (2) is filled with hydraulic oil (2) from the hydraulic oil discharge pipe outlet, and the piston is pushed 1.
The scavenging air control valve brocade is opened and the scavenging air hole (
3) becomes open.

To close the scavenging hole (3) at a predetermined time, open the pulp at Liugyo signal 4 with the pulp closed from the state shown in Figure 10. Then, (5) shown in Figure 8. The piston ■ is pushed by the force of K spring 4, and the hydraulic oil (2) in the hydraulic cylinder device is discharged through the hydraulic oil discharge pipe U, and the scavenging control valve !l is closed to perform scavenging. Stomata (
3) is closed. Alternatively, with the scavenging air control valve (one set open), the normal Uni-70-sweep, air-type aircraft
The scavenging hole (3) may be closed by the piston itself based on the movement of the piston 11, and then the hydraulic cylinder device may be operated at an appropriate time to close the scavenging control valve/candy.

FIG. 12 shows the changes in the scavenging hole opening period of the devices shown in FIGS. 8 to 11. In other words, the scavenging control valve (
By linking II1 with the movement of the piston of 1IAW4 or the rotation of the crankshaft), the timing on the side of the first scavenging hole (3) is delayed to near the bottom dead center position of the piston without reducing the opening area of the scavenging hole (3). In addition, if necessary, the scavenging hole (3
), it is possible to easily control the scavenging timing to the optimum timing and to supply a sufficient amount of air into the cylinder (4).

(6) In the embodiments shown in Figures 8 to 11, a compression spring is used to push back the piston, or as shown in Figure 913, it is attached to the body of the main body. Connect the first hydraulic oil supply/discharge system and the second hydraulic oil supply/discharge system, respectively, and press each surface of the piston (2) with hydraulic oil to operate it. Good too. (Incorporated) - - are pulps, - - - are control signals for operating each pulp (2) - -.

In the embodiment described above, the scavenging control valve is driven reciprocatingly in the circumferential direction by a cylinder device, but by combining the cylinder device and a known ratchet device, the scavenging control valve is sequentially driven in one direction in the circumferential direction. There is no harm in letting it happen.

As mentioned above, according to the vAK of the present invention, the scavenging control valve is disposed on the outer peripheral surface of the cylinder so that it can be moved in the circumferential direction, so that the valve can be opened and closed smoothly by driving only one part of the scavenging control valve. Not only is it possible to operate the cylinder, but it is also possible to delay the opening of the air extraction hole without reducing the scavenging opening area, and therefore (7) it is also possible to delay the opening of the exhaust valve, thereby increasing the effectiveness of the expanding gas in the cylinder. Work can be increased and the efficiency of the agency can be greatly improved.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing a normal uniflow scavenging type Shinyu.
Fig. 2 is an example of the pV diagram of the engine shown in Fig. 1, Fig. 3 is an enlarged view of section A in Fig. 2, Fig. 4 is a diagram in which the horizontal axis in Fig. 3 is replaced with the crank angle, Fig. 9, and Fig. 5. 7 to 7 show the case where the height of the scavenging hole is lowered by lowering the upper edge of the scavenging hole, FIG. 5 is a cross-sectional plan view of the cylinder, FIG. 6 is a view taken along the line B-B in FIG. 5,
Fig. 7 is a diagram showing the opening area of the scavenging and exhaust holes when the cylinder is used, Figs. 8 to 12 show an embodiment of the present invention, and Fig. 8 shows the closed state of the scavenging control valve. , Figure 9 is the 8th
Figure 10 shows the scavenging control valve in the open state, Figure 11 shows the scavenging control valve in the open state, Figure 11 shows the scavenging control valve in the D-D direction of Figure 10, and Figure 12 shows the scavenging control valve according to the present invention. FIG. 13 is a diagram illustrating an example of the area of the scavenging/exhaust hole when used, and FIG. 13 is a diagram showing another embodiment of the scavenging control valve driving cylinder. (8) Roto/scavenging hole, (4)...Cylinder, (5)-...
Exhaust valve, (1 (1... cylinder device na, -1. scavenging control valve, --. cylinder device, η... hydraulic oil supply pipe, I-. hydraulic oil discharge pipe, - 1- Pulp, (2
)(2)-・Control signal agent Morimoto
Yoshihiro (9) Figure f Tube? Figure~ \ \ \ 1st? Figure 91 Figure 13

Claims (1)

[Claims] 1. An annular scavenging air control valve that is fitted onto the scavenging hole portion of the cylinder screw and has a through hole having the same circumferential pitch as the scavenging hole is arranged so as to be slidable in the circumferential direction on the outer circumferential surface of the cylinder screw. A uniflow scavenging engine with a scavenging control valve.