JPS58110816A - Scavenging type engine with scavenging control valve - Google Patents

Abstract

PURPOSE:To steadily prevent cylinder interior from gas leakage by providing a scavenging control valve which is possible to be intermitted in radial direction of a cylinder to a outside surface of a scavenging port part of a cylinder liner. CONSTITUTION:Scavenging ports 1 in a scavenging engine are provided as piercing liner on the whole periphery of a designated location on a lower part of a cylinder liner 2, and a pair of semicircular scavenging control valves 13a, 13B are provided on the periphery of a part having scavenging ports 1 of said liner 2. One end of both valves 13A, 13b is mutually connected as able to swing around a pin 14, and other end of said valves 13A, 13B are connected with each cylinder device 15A, 15B by pins 16A, 16B. Said scavenging control valves 13A, 13B are closed by the action of the hydraulic cylinder device 15A, 15B, and opened at the predetermined opening time.

Description

[Detailed description of the invention] The present invention relates to a scavenging engine having a scavenging control valve.

For example, in a uniflow scavenging engine in which air flows into the cylinder through the scavenging hole and combustion gas in the cylinder is exhausted through the exhaust valve, conventional methods for improving the thermal efficiency of the engine include delaying the opening timing of the exhaust valve. It is widely known to increase the work of expansion within the cylinder.

In other words, Figure 1 shows the pressure chart near the bottom dead center of a uniflow scavenging engine, and the indicated mean effective pressure is increased by opening the exhaust valve later than in the normal case. It explains things.

Now, the exhaust diagram coefficient iygex is defined by the following equation using the indicated mean effective pressure pi and the margin Δpm for increasing the effective work as shown in the shaded area in FIG.

Dagex--1L-1 ・・・・・・(1) p1
+Δpi In the above formula, '[ex=10096 is Δpi=oOk
gf/d, and indicates that there is no room for increasing the effective work by further delaying the opening timing of the exhaust valve.

Figure 2 shows the above exhaust diagram coefficient when the exhaust valve opening timing is delayed in a uniflow scavenging engine, and the changes in the fuel consumption rate based on the normal exhaust valve opening timing, respectively. This is a turtle showing the results of an analysis (based on computer simulation). As shown in Figure 2), by delaying the opening timing of the exhaust valve, the fuel consumption rate is lowered and the thermal efficiency is improved. The plot coefficient will reach almost 100%.

However, if the opening timing of the exhaust valve is delayed, the gas pressure in the cylinder is still high even when the scavenging hole is open, and the combustion gas flows back from the cylinder to the scavenging chamber. This may cause various problems. Therefore, in the past, various attempts have been made to delay the opening timing of the scavenging holes by delaying the opening timing of the exhaust valve.

In other words, the scavenging hole is opened and closed by something other than a piston.

For example, various methods have been proposed in which the scavenging control valve is provided on the outer periphery of the cylinder liner. However, even with these conventional proposals, the problem is 0).

It is said that the scavenging control valve is one that slides vertically or locally along the cylinder liner, so it is impossible to reduce the surface pressure on the sliding and i1 surface, making it impossible to prevent gas leakage in the cylinder. There was a problem.

Therefore, the present invention solves the above-mentioned problems of the prior art, and the scavenging control valve is capable of preventing gas leakage in the cylinder by increasing force when pressing the scavenging control valve against the cylinder liner and increasing its surface pressure. The purpose of the present invention is to provide a scavenging type engine having the following characteristics.

In order to achieve the above object, the present invention provides a scavenging air control valve that is capable of coming into contact with and moving away from the outer surface of the scavenging hole portion of the cylinder liner in the radial direction of the cylinder liner. The aim is to obtain a scavenging engine with the following characteristics.

Embodiments of the present invention will be described below based on FIGS. 8 to 1.

8 to 6 explain the operating principle of a scavenging type engine having a scavenging control valve according to the present invention. That is, ((3) is a scavenging hole provided in the cylinder liner (2), and (3) is a scavenging control valve that can be moved into contact with and moved away from the cylinder liner (2) in the radial direction. The figure and the fourth factor show the closed state, and the figures 6 and 6 show the open state. In Fig. 6, the arrows indicate the flow of scavenging air.

FIG. 7 shows the first embodiment, in which a pair of semi-annular scavenging control valves (18A) (18B) are provided on the outer periphery of the portion of the cylinder liner (2) having the scavenging holes (1). The ends thereof are connected to each other so as to be swingable around a pin Q4 fixed near the cylinder liner (2). A hydraulic cylinder device l (tjA) (ts
B) Connected by 6g bottles (1@A) (16B). By operating the hydraulic cylinder device F (15AX15B), the closed state shown in Fig. 7 CJ &) and (b)
The switch can be switched to the open state shown in FIG.

In the above embodiment, when the gas is overfilled in the cylinder liner (2), the W value control valve (15A) (15B) shown in FIG. IIA) (JIB) is closed. Now, when the predetermined scavenging hole period is reached, the hydraulic cylinder device t (16
When A) (16B) is applied, the scavenging control valves (18A) (18B) are opened and the scavenging holes (
1) becomes open. To close the scavenging hole (1) at a predetermined time, the hydraulic cylinder device (15A) (16B) may be operated in the opposite manner to the above case, or the scavenging control valve (1aA) (18B) may be opened. Just like a normal scavenging engine.

The scavenging hole (1) is closed by the piston itself based on the movement of the piston of the engine, and then the hydraulic cylinder system* (15A) (15B) is operated at an appropriate time to close the scavenging air control valve (
18A) (18B) may be closed. In addition,
Scavenging control valve (18A) for the outer surface of the cylinder liner (2)
) force (NIB) pressing ζm is the hydraulic cylinder device f (t
sA) (16B) can be adjusted appropriately, a predetermined surface pressure can be obtained, and gas leakage can be prevented.

FIG. 8 shows a second embodiment. That is, on the outer surface of the cylinder liner (2) where the scavenging hole (1) exists, there are bottles (24a) (24b>(24c) (24d)).
Hydraulic cylinder equipment through (25m) (26b)
(25c) and (26d) are provided with a pair of semi-annular scavenging control valves (28A) and (28B) whose opposite ends are respectively connected. Nishiki 8 (a) is closed bark m.

(b) shows the open state.

FIG. 9 shows the eighth implementation side, in which a spring material is used for the scavenging pipe sub-valve (2). In this case, due to the elasticity of the spring material, the scavenging air control valve (to) will spread evenly when it is switched from the closed state shown in (a) to the open state shown in (b). Therefore, the scavenging control valve (to) is controlled by the hydraulic cylinder device N by the bottle (84A) (!14B).
(15A) (lISB), and the force can be applied to only two points for sufficient operation.

In addition, as shown in %allOffl, the cylinder liner (
2) The outer surface of the part having the scavenging hole (l) and the scavenging control valve (
3) means that one or both of the abutting parts has a contact seat whose contact area is smaller than that of the corresponding abutting part,
The pressing force may be weakened to maintain airtightness. In other words, the pressure on the cylinder liner (2
) has a counter seat (4a) with an airtight ring, (
In b), the cylinder liner (2) is integrally equipped with the counter seat (4b), and in (c), the scavenging control valve (3) is integrated with the counter seat (4c).
).Furthermore, both the cylinder liner (2) and the scavenging air control valve (3) may have a stopper seat, and the contact seats may be brought into contact with each other.

Further, although not shown in the above embodiments, if appropriate guides are provided above and below the movement path of the scavenging control valve, it is possible to prevent backlash in this direction. Furthermore, although the pitch of the scavenging holes in the cylinder liner portion corresponding to the end of the scavenging air control valve is widened, it is also possible to make this part the same pitch as other parts and narrow the gap between the ends of the scavenging air control valve. good,
In addition, the scavenging control valve shown in FIGS. 7 and IIB may be constructed of a suitable spring material.

As described above, according to the present invention, the scavenging control valve can be brought into contact with and moved away from the cylinder liner in the radial direction, so that the pressing of the scavenging control valve against the cylinder liner is controlled by controlling the surface pressure by adjusting the force, so that the gas inside the cylinder is Furthermore, since it does not have a conventional sliding structure, it is possible to prevent sticking during opening and closing, and it is also possible to prevent abrasion of the contact portion between the cylinder liner and the scavenging air control valve.

[Brief explanation of the drawing]

Figure 1 is a shiatsu diagram near the bottom dead center of a uniflow scavenging engine, and Figure 2 is a graph of changes in exhaust diagram coefficient and fuel consumption rate when the exhaust valve opening timing is delayed at T in a uniflow scavenging engine. Diagram showing computer simulation results, No. 8
Figures ~ 1 QI/ show embodiments of the present invention % Figures 3 ~ 6
The figures are diagrams explaining the operating principle, and FIG. 8 is a diagram showing the closed state, FIG. 4 is a N-W sectional view of the ms diagram, FIG. 5 is a diagram showing the open state, and FIG. ■-■ cross-sectional view of Figure 5, No. 7
8 is a diagram showing an embodiment of @1, FIG. 8 is a diagram showing a second embodiment, FIG. 99 is a diagram showing an embodiment of IIB, and No. 11 is a diagram explaining a hit seat. (1)...Scavenging hole, (2)...Cylinder liner, (
3) (18A) (IIB) (jIIIA) (RIB)
N-...Scavenging air control valve, (4aX4bX4c)...Treasury agent Yoshihiro Morimoto Shiri) Flesh pressure variable 9 (ri leX de 0 φ -'-'9
G-. Figure 6 Figure 4 Figure 5 Figure 1 Figure 7 Figure 1 ρ (a) (shi) (C) r

Claims (1)

[Claims] 1. To the outer surface of the scavenging hole portion of the cylinder liner. A scavenging type engine having a scavenging control valve, characterized in that the scavenging control valve is movable into and away from the cylinder liner in a radial direction. L The outer surface of the scavenging hole part of the cylinder liner and the scavenging control valve are as follows:
2. A scavenging type engine having a scavenging control valve according to claim 1, wherein one or both of the abutting portions has a contact seat having a smaller contact area than the corresponding abutting portion.