SU1668713A1 - Four-stroke internal combustion engine - Google Patents

Abstract

The invention improves the energy, economic and environmental performance of a four-stroke internal combustion engine. The engine contains a cylinder 1 with a piston 2, a head 3, a combustion chamber 6, an inlet 4 and an exhaust 5 channels and a gas distribution chamber 7, made in the head 3 and communicated by valve 8 to the combustion chamber 6, valve 9 with the inlet channel 4 and valve 10 with the exhaust channel 5. Moreover, valves 8, 9, 10 are driven by separate cams located on the camshaft (PB) for each valve, the profile of which has valve opening phases, including the values of the leading and opening latency angles, as well as the main angular range A developing: a first valve for 360 ° of crankshaft rotational angle (CPC), including the exhaust and intake strokes

for the second valve 180 - 360 ° according to the CPC, including the intake stroke and partially or fully compression stroke

for the third valve 180 - 360 ° according to the CPC, including the exhaust stroke and partially or fully expansion stroke. In embodiments, the main angular range of the valve opening zone 9, 10 is 360 ° to ensure uniformity of the cam profile PB and 270 ° to improve the cleaning of the fresh charge of the exhaust gases. 2 hp f-ly, 3 ill.

Description

FIG. I

The invention relates to mechanical engineering, in particular to engine building, namely to four-stroke internal combustion engines, preferably with positive ignition.

The aim of the invention is to increase energy, economic and environmental performance.

Figure 1 presents the proposed engine; Fig. 2 shows the valve opening phases.

The engine includes a cylinder 1c with a piston 2 disposed therein, a cylinder 3 of cylinder 1 with inlet 4 and exhaust 5 channels, a combustion chamber 6 formed by the head 3 and a piston 2 and having an ignition source, such as a spark plug (not shown), and a gas distribution chamber 7, made in the head 3, located between the combustion chamber 6 and the channels 4 and 5 and communicated with the combustion chamber 6 through the first valve (not shown) controlled bypass valve 8 and with the channels 4 and 5, respectively, controlled by the second and third cams (not shown s) 9 intake and exhaust 10 valves. The cams are located on the camshaft (not shown). With this arrangement of valves, it is possible to increase their size.

The cam profiles provide the valve opening phases shown in Fig. 2 in the graph of valve stroke h versus crankshaft angle (UPKV). The valve 8 has an opening phase, characterized by curve 11 and consisting of a main angular range of 360 °, including discharge steps 12 and inlet 13, as well as two additional ranges — opening 14 ahead of time and delay 15 of valve 8. The valve 9 has the shape of an open curve 16 and consisting of a main angular range of 360 ° including intake and compression cycles 17. as well as two additional ranges — opening ahead of 18 and delay 19 of closing valve 9. Valve 10 has an opening phase characterized by curve 20 and From the main angular range of 360 °, including expansion strokes 21 and outlet 12. As well as two additional ranges — opening ahead of time 22 and delaying closing valve 23 of valve 10.

For valve 8, the frontal opening range 14 is the same as the inlet valves of the known serial 4-stroke spark engines, for example, with one inlet valve per cylinder, and the 15 delayed closing range is the same as the exhaust valves of the known internal combustion engines. For valves 9 and 10, the leading ranges 18 and 22 of opening and closing 19 and 23 are the same. like valve 8.

Figure 2 shows a variant of unification.

Cams of all three valves 8-10. In the variant version (FIG. 3), the cam profiles of the valves Y and 1Q can provide earlier closing of valve 9 and later opening of valve 10 in order to exclude

0 closing (simultaneous opening) of valves 9 and 10 in the zone of 540 ° of the angle of rotation of the crankshaft and reduction due to this contamination of the fresh charge with the exhaust gases. At the same time, to prevent growth

5 the aerodynamic resistance of the valves 8 and 9 to the inlet, the valve 9 in the second half of the intake stroke must be larger than the valve 8, in particular, it can be fully opened, which is achieved with its basic angular range of the opening phase of 270 ° (180 ° of the intake stroke and 90 ° compression stroke). For the same reasons, a basic angular range of the opening phase of the valve 10 is provided, equal to 270 ° (180 ° discharge stroke

5 and 90 ° expansion stroke).

The engine works as follows.

In the expansion stroke, valve 8 is closed, valve 9 is basically also closed, and valve

0 10 to the middle (Fig. 2) or to the end (Fig. 3) of the expansion stroke fully opens. At the subsequent exhaust stroke, valve 8 opens, with valve 10 fully open at the beginning of the exhaust stroke, the resistance is exerted, and valve 8 and 10 are constantly opening the main throttling resistance. In the middle of the exhaust stroke, both valves 8 and 10 are fully open. At the end of the release stroke

0, the valve 8 is fully open, and the main throttling resistance is exerted by the closing valve 10. Thus, the release zone 24 shaded in Figures 2 and 3, despite the two exhaust valves 8 and 10. always formed by the resistance of one valve - valve 8 at the beginning of the release and valve 10 at the end of the release. If we consider that the flow area of these valves, especially valve 8.

0 is significantly overestimated in comparison with the known engines, the total time - the cross section is higher, the resistance is lower and, as a result, the cleaning of the combustion chamber 6 from exhaust gases (EG) is improved.

5 During the subsequent intake stroke, valve 8 is completely open from the very beginning, and valve 9 begins to open with some advances, creating the main throttling resistance in the initial part of the intake stroke. In the middle part both

valves 8 and 9 are fully open, and in the final part of the intake stroke, with valve 9 fully open, valve 8 is gradually closed, creating the main drilling resistance. Thus, the inlet zone 25, shaded in FIG. 2 and 3. is limited at the beginning of the stroke by opening the valve 9, and at the end of the stroke by closing the valve 8. t, e. at the beginning and at the end only one valve exerts the main throttling resistance. Since it is in the process of opening and closing the valve that a decisive aerodynamic resistance to the inlet is created, in the proposed engine it is almost equivalent to the resistance of one valve, although two consecutive valves 8 and 9 operate at the inlet. Because each of these valves allows a significantly larger cross-section than in known engines, time is a section through the opening of the intake valves 8 and 9, the filling of the engine and its energy performance increase. Valve 8, alternately used as intake or exhaust, can be made with a much larger flow area and time-section than the intake and exhaust valves in known engines, even multi-valves, since only part of the combustion chamber can be attributed to the intake valves and the other part under the exhaust valves.

The flow sections of valves 9 and 10 can also be significantly larger than those of the intake and exhaust valves of known engines, since they are not related to the limited dimensions of the combustion chamber and there is a known freedom to arrange them around the combustion chamber.

During the subsequent compression stroke, valves 8 and 10 are closed, which allows valve 9 to be still closed during this stroke and use this stroke for closing valve 9, thereby ensuring its full opening at the end of the previous intake stroke. At the same time, closing of valve 9 can be completed by the end of the compression stroke (variant of unified cams, Fig. 2) or in order to prevent valves from closing in the 540 ° zone of the OPCW and contaminant exhaust mixture somewhat earlier, for example, by the middle of the compression stroke (Fig. 3) . which prevents the valves from closing and keeps valve 9 fully open at the previous cycle, but leads to the disconnection of the valves.

In the subsequent expansion stroke, valves 8 and 9 are closed, which allows this tact to be used to prepare for the subsequent discharge stroke, carried out the process of fully opening valve 10 to the beginning of the discharge stroke. In this case, the opening of the valve 10 may begin at the beginning of the expansion stroke 5 (a variant of the unified cams. Fig. 2) or somewhat later, for example, from the middle of the expansion stroke (Fig. 3). which prevents valves from overlapping in the 540 ° zone of the CPC, but retains the full opening of valve 10 at the beginning of the exhaust stroke.

The working process of burning the mixture is carried out in the combustion chamber 6, which, due to the placement of just one valve 8 in it, can be very compact,

5 e.g. round section. This causes a relatively small surface heat transfer to the walls, as well as a relatively high degree of compression due to the absence of peripheral zones remote from the candle.

0 are sources of detonation and are characteristic of multi-valve combustion chambers. A decrease in heat transfer and an increase in the degree of compression lead to an increase in the indicator efficiency and a decrease in fuel consumption.

5 The peculiarity of the working process of the proposed engine is also associated with the influence of residual exhaust gases in the gas distribution chamber 7 on the combustion of the mixture. Positive side of it

0 influence in that. that additional residual exhaust gases from chamber 7 play the same role that many modern internal combustion engines play specially organized exhaust gas recirculation from the exhaust pipe to the combustion chamber5 in order to reduce the content of nitrogen oxides. To this end, the volume of chamber 7 can be specially - bir; ts to obtain the desired effect on the reduction of nitrogen oxides. Besides,

Claims (2)

0 at low loads, residual exhaust gases from chamber 7 reduce pumping losses and additionally reduce fuel consumption, claims 1. A four-stroke engine of internal combustion containing at least one cylinder with a piston placed in it, a cylinder head with inlet and exhaust channels, a combustion chamber formed by the head and piston and having an ignition source and a gas distribution chamber, made in the head, located between the combustion chamber and the channels and communicated with the combustion chamber through a control minutes per5 vym cam overflow valve and through channels respectively controlled by the second and third cams intake and exhaust valves, wherein the first cam is adapted to the opening of the bypass valve during the exhaust stroke and the intake, the second cam — with the possibility of opening the intake valve during the intake stroke, and the third cam — with the possibility of opening the exhaust valve during the exhaust stroke, characterized in that, in order to improve energy, economic and environmental performance, the second cam is made with the possibility of continued opening of the intake valve during part or all of the compression stroke and exceeding the opening of the intake valve over the opening of the overflow valve in the second half of the intake stroke, and the third coolant choke - with the possibility of continued opening of the exhaust valve during part or all of the expansion stroke and exceeding the magnitude of exhaust valve opening value otkry0 These bypass valves in the first half of the exhaust stroke. 2. The motor according to claim 1, characterized in that, in order to simplify manufacture, the second and third cams are made with profiles that coincide with the profile of the first cam. 3, engine according to claim 1, distinguished by the fact that, in order to reduce the fresh charge pollution by the exhaust gases, the second and third cams are made with the same profiles, and the second cam is made with the possibility of continued opening of the intake valve during the first half of the compression stroke and the third cam, with the possibility of continued opening of the exhaust valve during the second half of the expansion stroke. MO / / 0 and 22 W 7209 FIG. 21 20