JP2010275988A - Valve device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remarkably enhance scavenging efficiency by causing combustion gas to flow to a low-temperature chamber without branch flow. <P>SOLUTION: The valve device 20 for internal combustion engine includes a main valve 4 which opens and closes an exhaust port 2a; a high-temperature chamber 22 which introduces and discharges combustion gas of early exhaust discharged from the exhaust port 2a when the main valve 4 is opened; the low-temperature chamber 24 which introduces and discharges combustion gas discharged from the exhaust port between the middle period of exhaust and the completion of exhaust; and a sub-valve 31 which switches the flow of combustion gas between the high-temperature chamber and the low-temperature chamber. The sub-valve 31 includes a cylindrical portion 32 through which the combustion gas discharged from the exhaust port is passed; and a guide blade 33 disposed above the cylindrical portion to guide combustion gas discharged through an upper opening of the cylindrical portion to the high-temperature chamber during the early stage of exhaust and to the low-temperature chamber between the middle period of exhaust and the completion of exhaust. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a valve device for an internal combustion engine.

  As a valve device for an internal combustion engine, for example, an exhaust valve device for a two-cycle diesel engine, there are those shown in FIGS. As shown in FIGS. 6 and 7, the exhaust valve device 10 is disposed directly above the valve seat 3 of the exhaust port 2 a provided at the top of the combustion chamber 2 of the cylinder block 1. In the cylinder head 11, which is a part of the cylinder head 11, a high temperature chamber 12 and a high temperature exhaust passage 13 communicating with the high temperature chamber 12 are formed in the upper portion, and a low temperature chamber 14 and low temperature exhaust communicating with the low temperature chamber 14 are formed in the lower portion. A passage 15 is formed.

  The high temperature chamber 12 and the low temperature chamber 14 are disposed above the exhaust port 2a and communicate with the exhaust port 2a. The lower end portion 16 a of the hydraulic cylinder block 16 is provided with a guide vane 17 for smoothly guiding high-temperature combustion gas (exhaust gas) to the high-temperature chamber 12 and the high-temperature exhaust passage 13 in the vicinity of the lower center of the high-temperature chamber 12. Yes.

  On the other hand, the umbrella-shaped main valve 4 for opening and closing the exhaust port 2a of the combustion chamber 2 of the cylinder block 1 is provided at the upper end of the valve stem 5 and an air piston (not shown) housed in the air spring chamber 18 is provided. The valve is closed by being pushed up by air pressure. The main valve 4 opens when high pressure oil pressure is supplied to the upper end surface (not shown) of the valve stem 5 and the valve stem 5 is pushed down against the air pressure received by the air piston.

  On the other hand, the auxiliary valve 7 has a substantially cylindrical shape, and is fixed to the lower end portion of the auxiliary valve stem 8 by a plurality of radii (spokes) 7 a, and is accommodated in the air spring chamber 18 at the upper end portion of the auxiliary valve stem 8. An air piston 9 is attached. The valve stem 5 of the main valve 4 penetrates the pipe-like sub valve stem 8 of the sub valve 7 through a seal member (not shown) so as to be slidable and airtight. The main valve 4 and the sub valve 7 are It is a coaxial valve.

  The auxiliary valve 7 is pushed down by the air pressure applied to the air piston 9 provided at the upper end of the auxiliary valve stem 8 and closes the low temperature chamber 14 as shown in FIG. The auxiliary valve 7 opens the low temperature chamber 14 as shown in FIG. 7 when the auxiliary valve stem 8 is pushed upward against the air pressure of the air piston 9 by the hydraulic cylinder 19 in the hydraulic cylinder block 16. At the same time, the high temperature chamber 12 is closed together with the guide vanes 17.

  The sub-valve 7 closes the low temperature chamber 14 when the main valve 4 is closed and at the initial opening (exhaust initial), and is discharged from the combustion chamber 2 through the exhaust port 2a at the initial valve opening as shown in FIG. High-temperature and high-pressure combustion gas (exhaust gas) is discharged from the opening of the upper end 7 b as shown by the arrow, introduced into the high-temperature chamber 12 by the guide vanes 17, and exhausted through the high-temperature exhaust passage 13.

  Further, the sub-valve 7 is pushed upward by the hydraulic cylinder 19 as shown in FIG. 7 from the middle of the opening of the main valve 4 until it closes (from the middle of the exhaust to the end of the exhaust). The lower end 7 c opens the low temperature chamber 14 and the opening of the upper end 7 b is sealed by the guide vanes 17 to close the high temperature chamber 12.

  As a result, the low-temperature and low-pressure combustion gas in the combustion chamber 2 is introduced into the low-temperature chamber 14 as indicated by an arrow, and exhausted (scavenged) through the low-temperature exhaust passage 15. In this way, the exhaust valve device 10 switches the flow of the combustion gas to the high temperature chamber 12 and the low temperature chamber 14 by one cylindrical sub valve 7.

  As an intake / exhaust valve device for an internal combustion engine, an exhaust port and an exhaust passage are provided in the upper part of the cylinder head, and an intake port and an intake passage are provided in the lower part, and exhausted by an intake / exhaust control valve (corresponding to a sub valve). An operation mechanism of an intake / exhaust valve of an internal combustion engine that alternately switches the inlet and the intake port has been proposed (see, for example, Patent Documents 1 and 2).

JP 63-289204 A (FIGS. 1 and 3) Japanese Utility Model Publication No. 64-22805 (page 6-9, FIG. 1)

  However, in the conventional exhaust valve device 10 shown in FIG. 6 described above, the combustion gas is switched to the high temperature chamber 12 disposed above the cylinder head 11 and the low temperature chamber 14 disposed below the high temperature chamber 12. Is performed by one cylindrical sub-valve 7, so that the opening of the upper end 7 b of the sub-valve 7 is shown in FIG. Is hermetically sealed by the guide vanes 17 to form a cylindrical shape with a bottom at the top.

  As a result, the flow of the combustion gas discharged from the combustion chamber 2 through the exhaust port 2a to the low temperature chamber 14 becomes a branch flow as indicated by an arrow, so that a branch loss occurs and the flow path resistance increases. As a result, there is a problem that the flow of the combustion gas to the low temperature exhaust passage 15 is deteriorated and the scavenging efficiency is remarkably deteriorated.

  Note that the operation mechanism of the intake and exhaust valves of the internal combustion engine described in Patent Documents 1 and 2 described above has an exhaust port and an exhaust passage in the upper part of the cylinder head, and an intake port and an intake passage in the lower part. In this structure, the exhaust port and the intake port are alternately switched by an intake / exhaust control valve (corresponding to a sub valve).

  Therefore, since the exhaust path is not composed of two exhaust chambers, a high temperature chamber and a low temperature chamber, when switching to the exhaust port by the intake / exhaust control valve, the combustion gas exhausted from the cylinder side is changed as described above. No branching flow is generated. That is, since intake air flows into the cylinder from outside during intake, the problem of branch flow does not occur even if the exhaust control valve has such a configuration.

  The present invention has been made to solve such a problem. In a valve device for an internal combustion engine, which uses a sub valve to switch a flow of combustion gas to a high temperature chamber and a low temperature chamber disposed below the high temperature chamber. Another object of the present invention is to provide a valve device for an internal combustion engine that can significantly improve the scavenging efficiency by preventing a branch flow from occurring in the flow of combustion gas to the low temperature chamber.

  In order to solve the above-mentioned problems, the means employed by the present invention includes a main valve that opens and closes an exhaust port provided at the top of the combustion chamber of the cylinder block, and a main valve that is disposed in the cylinder head and that opens the main valve. A high-temperature chamber that introduces and exhausts combustion gas at the initial stage of exhaust discharged from the exhaust port at the time of the valve, and a combustion that is disposed under the high-temperature chamber in the cylinder head and exhausted from the exhaust port from the middle of the exhaust to the end of exhaust In a valve device for an internal combustion engine comprising a low-temperature chamber that introduces and exhausts gas, and a sub-valve that is housed in a cylinder head and switches the flow of combustion gas to the high-temperature chamber and the low-temperature chamber, The cylinder part through which the combustion gas discharged from the opening passes, and the combustion gas disposed above the cylinder part and discharged from the upper end opening of the cylinder part are exhausted to the high temperature chamber at the beginning of exhaust and exhausted from the middle of the exhaust Guide to the cold room until It lies in the fact consisting of a.

  In the secondary valve, the cylinder portion closes the low-temperature chamber in the initial stage of opening the main valve, and high-temperature and high-pressure combustion gas discharged from the exhaust port of the combustion chamber in the initial stage of opening the main valve is in the cylinder portion of the secondary valve. Then, the gas is discharged from the upper end opening, introduced into the high temperature chamber by the guide vanes disposed above the cylinder, and then exhausted to the outside.

  The sub-valve is switched to almost the middle opening of the main valve, and during the period from the middle opening of the main valve to the closing, the low-temperature and low-pressure combustion gas discharged from the exhaust port of the combustion chamber passes through the cylinder of the sub-valve. The air is discharged from the upper end opening, introduced into the low temperature chamber by the guide vanes, and then exhausted to the outside. Thus, since the combustion gas discharged from the exhaust port of the combustion chamber is discharged from the upper end opening of the sub valve, no branch flow is generated in the vicinity of the sub valve as in the prior art.

  In the valve device for an internal combustion engine described above, the cylinder portion of the auxiliary valve slides in an airtight manner in the opening portion of the low temperature chamber communicating with the exhaust port to open and close the low temperature chamber, and the guide vanes form a substantially funnel-shaped cylinder. It is desirable to form an annular passage between the upper end opening portion of the cylinder portion in cooperation with the upper portion, and to open and close the opening portion of the high temperature chamber whose upper end portion communicates with the exhaust port.

  The auxiliary valve is a high-temperature and high-pressure combustion that is discharged at the initial opening of the main valve when an annular passage between the upper end opening of the cylinder part opens into the high-temperature chamber when the cylinder part closes the low-temperature chamber. Lead the gas to the hot chamber. The sub-valve is switched to almost the middle of the main valve opening so that the cylinder portion opens the low temperature chamber, the upper end of the guide blade closes the high temperature chamber, and the annular passage opens to the high temperature chamber. During the period from the middle of the valve opening to the closing of the valve, the low-temperature and low-pressure combustion gas discharged is guided from the annular passage to the low-temperature chamber through the cylinder portion. Thereby, it can be ensured that a branch flow is not generated in the flow of the combustion gas to the low temperature chamber.

  In the valve device for an internal combustion engine described above, the sub-valve has an annular passage that opens to the high temperature chamber when the cylinder portion closes the low temperature chamber, and the upper end portion of the guide blade closes the high temperature chamber. It is desirable for the annular passage to open into the cold chamber.

  The sub-valve guides the high-temperature and high-pressure combustion gas discharged at the initial opening of the main valve to the high-temperature chamber when the cylindrical part closes the low-temperature chamber and opens to the high-temperature chamber, When the upper end closes the high-temperature chamber, the annular passage opens into the low-temperature chamber and guides the low-temperature and low-pressure combustion gas to the low-temperature chamber from the middle of the main valve opening to the closing. Thereby, the flow of the combustion gas to the high temperature chamber and the low temperature chamber can be switched by one sub valve, and the branch flow can be surely not generated in the exhaust flow to the low temperature chamber.

  In the valve device for an internal combustion engine described above, it is desirable that the cylinder portion of the auxiliary valve and the guide vane are integrally attached to the auxiliary valve stem that operates the auxiliary valve. In this way, by integrally attaching the cylinder portion of the auxiliary valve and the guide vane to one auxiliary valve stem, the cylinder portion of the auxiliary valve and the guide vane can be reliably interlocked with a simple structure.

  In the valve device for an internal combustion engine described above, it is desirable that the cylinder portion of the sub-valve has a tapered shape so that the inner lower portion communicates smoothly with the exhaust port. As described above, the cylinder portion of the auxiliary valve is tapered so that the inner lower portion thereof communicates smoothly with the exhaust port, and therefore, particularly when the auxiliary valve is lowered and the combustion gas is guided to the low temperature chamber. The combustion gas discharged from the exhaust port of the combustion chamber can smoothly flow into the cylindrical portion.

  In the above-described valve device for an internal combustion engine, it is desirable that the cylinder portion of the sub-valve has the lower end of the inner lower portion bent outward to be expanded in diameter, and the tip portion can close the low temperature chamber. In this way, by expanding the diameter of the lower end portion of the cylindrical portion, the low temperature chamber can be more reliably closed by the end surface.

  In the above-described valve device for an internal combustion engine, the guide blade is a guide surface having a smooth curved surface on the side facing the upper end opening of the cylindrical portion, and the combustion gas discharged from the upper end opening of the cylindrical portion It is desirable to smoothly lead to a low greenhouse.

  In this way, the guide blade is a guide surface having a smooth curved surface on the side facing the upper end opening of the tube portion, so that the combustion gas discharged from the upper end opening through the tube portion is It discharges along the guide surface of a guide blade from the annular passage formed between upper end openings. Thus, the combustion gas is smoothly introduced into the high temperature chamber and the low temperature chamber.

  In the above-described valve device for an internal combustion engine, it is desirable that the cylindrical portion, the guide vane, and the auxiliary valve stem are integrally formed by precision casting. As described above, the cylindrical portion of the auxiliary valve, the guide vane, and the auxiliary valve stem are integrally formed by precision casting, so that the manufacturing cost of the auxiliary valve having a complicated shape is greatly increased as compared with, for example, forging. Can be reduced.

  As described above, the valve device for an internal combustion engine according to the present invention includes a main valve that opens and closes an exhaust port provided at the top of the combustion chamber of the cylinder block, and is disposed in the cylinder head and is open when the main valve is opened. A high-temperature chamber that introduces and exhausts combustion gas at the initial stage of exhaust exhausted from the exhaust port, and a combustion gas that is disposed in the cylinder head below the high-temperature chamber and exhausted from the exhaust port from the middle exhaust stage to the end of exhaust. In a valve device for an internal combustion engine comprising a low-temperature chamber that is introduced and exhausted, and a sub-valve that is accommodated in the cylinder head and switches the flow of combustion gas to the high-temperature chamber and the low-temperature chamber, A cylinder part that allows the exhausted combustion gas to pass inside, and a combustion gas that is disposed above the cylinder part and exhausted from the upper end opening of the cylinder part to the high temperature chamber at the beginning of exhaust and from the middle stage of exhaust to the end of exhaust From the guide wing leading to the low greenhouse .

  Therefore, in a valve device for an internal combustion engine in which the sub-valve switches the flow of the combustion gas to the high temperature chamber and the low temperature chamber disposed below the high temperature chamber, a branch flow is not generated in the flow of the combustion gas to the low temperature chamber. Thus, the scavenging efficiency can be remarkably enhanced.

It is sectional drawing for showing the low temperature chamber especially of the exhaust valve apparatus of the internal combustion engine which concerns on one Embodiment of this invention. It is sectional drawing for showing the high temperature chamber of the exhaust valve apparatus shown in FIG. 1 especially. FIG. 3 is an explanatory diagram showing a flow of combustion gas introduced into a high temperature chamber in the exhaust valve device shown in FIG. 2. FIG. 4 is an explanatory diagram showing a flow of combustion gas introduced into a low temperature chamber in the exhaust valve device shown in FIG. 3. It is a graph explaining operation | movement of the main valve and subvalve of the exhaust valve apparatus shown to FIG. It is sectional drawing which shows the flow of the combustion gas introduce | transduced into the high temperature chamber especially of the exhaust valve apparatus of the conventional internal combustion engine. It is sectional drawing which shows the flow of the combustion gas especially introduce | transduced into the low temperature chamber of the exhaust valve apparatus shown in FIG.

  An embodiment for carrying out the invention of a valve device for an internal combustion engine of the present invention will be described in detail with reference to FIGS. FIG. 1 and FIG. 2 are cross-sectional views of main parts of an exhaust valve device for a two-cycle diesel engine in which the valve device for an internal combustion engine according to the present invention is implemented.

  As shown in FIGS. 1 and 2, the exhaust valve device 20 is disposed directly above the valve seat 3 attached to the exhaust port 2 a provided at the top of the combustion chamber 2 of the cylinder block 1. In the upper part of the cylinder head 21, a high temperature chamber 22 and a high temperature exhaust passage 23 communicating with the high temperature chamber 22 are formed, and a low temperature chamber 24 and the low temperature chamber 24 are communicated directly below the high temperature chamber 22 (downward). A low temperature exhaust passage 25 is formed. The high greenhouse 22 and the low temperature chamber 24 are located immediately above the exhaust port 2a and communicate with the exhaust port 2a.

  The high temperature chamber 22 and the low temperature chamber 24 have a substantially donut shape larger in diameter than the exhaust port 2a, and the inner diameters thereof, that is, the openings 22a and 24a communicating with the exhaust port 2a have substantially the same diameter. The diameter is slightly larger than the opening 2a. The center line in the opening direction of the high temperature exhaust passage 23 and the low temperature exhaust passage 25 is disposed at an angle of, for example, about 45 ° when the cylinder head 21 is viewed from above (see FIG. 2).

  As a result, the low temperature chamber 24 is disposed immediately below the high temperature chamber 22, and the opening 22 a of the high temperature chamber 22 and the upper end of the opening 24 a of the low temperature chamber 24 can be matched. That is, as shown in FIG. 1, the upper end of the opening 22a of the high temperature chamber 22 and the opening 24a of the low temperature chamber 24 are integrally formed.

  The valve stem 5 of the umbrella-shaped main valve 4 that opens and closes the exhaust port 2a of the combustion chamber 2 penetrates the pipe-shaped sub valve stem 34 of the sub valve 31 described later so as to be slidable in the axial direction. The upper part 5a is inserted into the hydraulic cylinder 48 of the casing 47 to form a hydraulic piston.

  An air piston 6 accommodated in the air spring chamber 45 is fixed to the upper portion of the valve stem 5 by a fixing member (not shown). The main valve 4 is closed when the air piston 6 is pushed up by the air pressure of the air spring chamber 45, high pressure oil pressure is supplied to the upper end surface 5 b of the valve stem 5, and the air piston 6 is pushed down against the air pressure. Open the valve.

  That is, the valve opening operation of the main valve 4 is performed by the hydraulic cylinder 48 that is operated by high-pressure oil pressure pushing the valve stem 5 downward in the figure, and the valve closing operation is attached to the valve stem 5. The air piston 6 is performed by pulling up the valve stem 5 upward in the figure. The air pressure in the air spring chamber 45 formed below the air piston 6 is the operating source for the valve closing operation of the main valve 4.

  For example, the sub valve 31 is integrally formed with a cylindrical portion 32, a guide vane 33 disposed above the cylindrical portion 32, and a pipe-shaped sub valve stem 34 that supports the cylindrical portion 32 and the guide vane 33. Thus, the main valve 4 and the coaxial valve are used.

  The cylindrical portion 32 can be slid in an airtight manner in the opening 24a of the low temperature chamber 24, and can close the opening 24a of the low temperature chamber 24 when moved to the upper limit position as shown in FIG. . In the cylindrical portion 32, a substantially central portion of the inner peripheral surface is connected to the lower end portion of the auxiliary valve stem 34 by a plurality of radii (spokes) 32 a.

  The lower portion 32b of the cylindrical portion 32 is tapered toward the exhaust port 2a and is reduced in diameter toward the lower side so as to have substantially the same diameter as the exhaust port 2a. Further, the lower end portion 32c is folded outward at a substantially right angle to expand its diameter, and the end surface thereof can be air-slidably contacted with the inner peripheral surface of the opening 24a of the low temperature chamber 24 as shown in FIG. .

  As a result, as shown in FIG. 1, the combustion gas discharged from the exhaust port 2a can be smoothly introduced into the cylindrical portion 32, and as shown in FIG. 2, the low temperature chamber 24 is formed by the lower end portion 32c. It is possible to block.

  As shown in FIG. 1, the guide vane 33 has a substantially funnel shape in which a lower end portion 33a has a small diameter and an upper end portion 33b has a large diameter. The lower end portion 33 a is connected to the vicinity of the upper end opening of the cylindrical portion 32 of the sub valve stem 34, and the upper end portion 33 b is disposed above the upper end portion 32 d of the cylindrical portion 32 with a predetermined interval. . An annular passage (opening) 35 is formed between the upper end portion 32 d of the cylindrical portion 32 and the guide vane 33. The annular passage 35 is for guiding the combustion gas discharged from the upper end opening of the cylindrical portion 32 to the high temperature chamber 22 or the low temperature chamber 24.

  The upper end portion 33b of the guide vane 33 has substantially the same diameter as the outer diameter of the cylindrical portion 32, and closes the opening 22a of the high temperature chamber 22 when the cylindrical portion 32 is lowered to the lower limit position as shown in FIG. It is possible. The outer surface 33c on the opening side of the cylindrical portion 32 extending from the lower end portion 33a to the upper end portion 33b of the guide vane 33 is a combustion gas guiding surface 33c, and is discharged from the upper end opening portion through the cylindrical portion 32. The combustion gas is smoothly guided to the low temperature chamber 24 shown in FIG. 1 or the high temperature chamber 22 shown in FIG.

  As described above, in the auxiliary valve 31, the annular passage 35 is formed between the upper end portion 32 d of the cylinder portion 32 and the guide vane 33, and the cylinder portion 32 and the guide vane 33 are integrated with the auxiliary valve stem 34. It is only necessary to have a structure in which the annular passage 35 is always formed by moving. Therefore, the cylindrical portion 32 and the guide vane 33 may be integrally formed and fixed to the lower end portion of the auxiliary valve stem 34, or the cylindrical portion 32, the guide vane 33, and the auxiliary valve stem 34 may be integrally formed. Good.

  In the latter case, the auxiliary valve stem 34 can be further divided into upper and lower parts, and the lower auxiliary valve stem, the cylindrical portion 32 and the guide vane 33 can be integrally formed by precision casting. For this reason, the manufacturing cost of the subvalve 31 having a complicated shape can be significantly reduced as compared with, for example, the case of forging. FIG. 1 shows a case where a cylindrical portion 32, a guide vane 33, and a lower auxiliary valve stem 34 are integrally formed. The upper sub valve stem 34 and the lower sub valve stem 34 are connected by welding, for example.

  Further, the cylindrical portion 32 and the guide vane 33 are formed separately and the annular portion 35 is formed between the upper end opening of the cylindrical portion 32 and the cylindrical portion 32 and the guide vane 33 are connected to the auxiliary valve stem 34. You may make it fix to.

  As shown in FIG. 1, the opening end 3 a on the cylinder head 21 side of the valve seat 3 is substantially the same diameter as the opening 24 a of the low-temperature chamber 24 over a predetermined length (depth). When 32 is lowered to the illustrated lower limit position, a slight gap is provided between the lower end portion 32 c and the valve seat 3.

  And when the cylinder part 32 descend | falls to the illustrated lower limit position and obstruct | occludes the opening part 24a of the low temperature chamber 24, the lower end part 32c is prevented from seating on the valve seat 3. Since the impact is prevented by preventing the lower end portion 32c of the cylindrical portion 32 from being seated on the valve seat 3 in this way, the auxiliary valve 31 can be formed by precision casting rather than forging. ing.

  The sub-valve stem 34 penetrates the hydraulic block 41 and protrudes into the air spring chamber 45 of the casing 44, and the air piston 9 accommodated in the air spring chamber 45 is fixed to the upper end portion thereof by a fixing member (not shown). Yes. As shown in FIG. 1, in the auxiliary valve 31, when the air piston 9 is pushed down by the air pressure of the air spring chamber 45, the guide vane 33 closes the opening 22 a of the high temperature chamber 22, and the annular passage 35 is the low temperature chamber 24. Open to.

  As shown in FIG. 2, when the air piston 9 is pushed upward against the air pressure by the plurality of hydraulic cylinders 42 provided in the hydraulic cylinder block 41, the sub-valve 31 closes the low temperature chamber 24 by the cylindrical portion 32. The annular passage 35 opens into the high temperature chamber 22.

  That is, the switching operation of the flow of the combustion gas from the auxiliary valve 31 to the low temperature chamber 24 and the high temperature chamber 22 is performed by the plurality of hydraulic cylinders 42 provided in the hydraulic cylinder block 41 moving the air piston 9 upward in the figure by high pressure oil pressure. This is done by pushing. Further, the restoring operation is performed by releasing the hydraulic pressure of the plurality of hydraulic cylinders 42 and pushing the sub valve stem 34 downward by the air piston 9. The air pressure in the air spring chamber 45 formed above the air piston 9 is the operating source for the recovery operation of the sub valve 31.

  In order to avoid complication of the drawing, the hydraulic cylinder block 41 and the auxiliary valve penetrating the hydraulic cylinder block 41 are arranged between the auxiliary valve stem 34 and the valve stem 5 of the main valve 4 passing through the auxiliary valve stem 34. The seal member inserted between the stem 34 is omitted.

  As shown in FIG. 1, when the main valve 4 is closed, the auxiliary valve 31 has an upper end 33 b of the guide vane 33 that closes the opening 22 a of the high temperature chamber 22, and an annular passage 35 is connected to the low temperature chamber 24. It is open. When a piston (not shown) in the combustion chamber 2 passes the top dead center (TDC), as shown in FIG. 2, the auxiliary valve 31 is pushed upward and the cylinder portion 32 closes the opening 24 a of the low temperature chamber 24. An annular passage 35 between the upper end 33 d of the cylindrical portion 32 and the guide blade 33 opens into the high temperature chamber 22.

  As shown in FIG. 3, when the main valve 4 is opened, the high-temperature and high-pressure combustion gas discharged from the combustion chamber 2 through the exhaust port 2 a passes through the cylindrical portion 32 of the sub-valve 31 and passes through the annular passage. As shown by the arrow along the guide surface 33 c from 35, the air smoothly flows into the high temperature chamber 22 and is discharged to the high temperature exhaust passage 23.

  The sub-valve 31 is pushed down as shown in FIG. 4 when the piston reaches the bottom dead center (BDC) and the main valve 4 is in the middle of the valve opening, so that the upper end 33b of the guide vane 33 opens the high-temperature chamber 22. The portion 22 a is closed and an annular passage 35 opens into the low temperature chamber 24.

  Thereby, the low-temperature and low-pressure combustion gas discharged from the exhaust port 2a passes through the inside of the cylindrical part 32 as shown by the arrow until the valve is closed from the middle of the opening of the main valve 4 to the upper opening, The air smoothly flows into the low temperature chamber 24 along the guide surface 33 c from the annular passage 35 and is discharged to the low temperature exhaust passage 25.

  Since the upper end of the cylindrical portion 32 of the auxiliary valve 31 is open, the low-temperature and low-pressure combustion gas discharged from the exhaust port 2 a is not generated in the cylindrical portion 32 until the valve is closed from the middle of the opening of the main valve 4. Through the top opening. Thereby, a branch flow is prevented from being generated in the flow of the combustion gas to the low temperature chamber 24. As a result, the branching loss is eliminated, and the combustion gas can be smoothly exhausted from the middle of the opening of the main valve 4 until the valve is closed, and the scavenging efficiency is remarkably improved.

  The valve device 20 returns to the state shown in FIG. 1 when the main valve 4 is closed. FIG. 5 shows the operations of the main valve 4 and the sub valve 31 of the exhaust valve device 20 described above, the graph shown by a thick line shows the operation of the main valve 4, and the graph shown by a thin line shows the operation of the sub valve 31. Yes.

  The present invention is not limited to the valve device for a two-cycle diesel engine according to the above-described embodiment, but is implemented for a valve device for a four-cycle diesel engine and various other valve devices for an internal combustion engine. Is possible.

DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Combustion chamber 2a Exhaust port 3 Valve seat 3a Open end 4 Main valve 5 Valve stem 5a Upper part 5b Upper end surface 6 Air piston 7 Sub valve 7a Radiation (spoke)
7b Upper end 7c Lower end 8 Sub valve stem 8
9 Air piston 10 Exhaust valve device 11 Cylinder head 12 High greenhouse 13 High temperature exhaust passage 14 Low greenhouse 15 Low temperature exhaust passage 16 Hydraulic cylinder block 16a Lower end 17 Guide vane 18 Air spring chamber 19 Hydraulic cylinder 20 Exhaust valve device 21 Cylinder head 22 High temperature Chamber 22a Opening 23 High-temperature exhaust passage 24 Low greenhouse 24a Opening 25 Low-temperature exhaust passage 31 Sub valve 32 Tube 32a Radiation (spoke)
32b Lower 32c Lower end 32d Upper end 33 Guide vane 33a Lower end 33b Upper end 33c Guide surface 34 Sub valve stem 35 Annular passage 41 Hydraulic cylinder block 42 Hydraulic cylinder 44 Casing 45 Air spring chamber 47 Casing 48 Hydraulic cylinder

Claims (8)

  A main valve (4) for opening and closing an exhaust port (2a) provided at the top of the combustion chamber (2) of the cylinder block (1), and a main valve (4) disposed in the cylinder head (21). A high-temperature chamber (22) for introducing and exhausting combustion gas at the initial stage of exhaust exhausted from the exhaust port when the valve is opened, and being disposed in the cylinder head below the high-temperature chamber and exhausting from the middle stage of exhaust A low-temperature chamber (24) for introducing and exhausting the combustion gas discharged from the exhaust port, and being disposed in the cylinder head and switching the flow of the combustion gas to the high-temperature chamber and the low-temperature chamber In the valve device (20) of the internal combustion engine provided with the auxiliary valve (31), the auxiliary valve includes a cylinder part (32) through which the combustion gas discharged from the exhaust port passes, and an upper part of the cylinder part. Arranged at the upper end opening of the tube The valve device of the discharged above the combustion gas into the hot chamber to the exhaust initial and from the exhaust metaphase to said exhaust ends internal combustion engine characterized by comprising from the guide vanes (33) leading to the cold room.   The cylinder part (32) of the sub-valve (31) slides in an airtight manner in the opening (24a) of the low temperature chamber (24) communicating with the exhaust port (2a) to open and close the low temperature chamber. The guide vane (33) has a substantially funnel shape and cooperates with the cylindrical portion (32) to form an annular passage (35) between the upper end opening of the cylindrical portion and the upper end portion ( The valve device for an internal combustion engine according to claim 1, wherein 33b) opens and closes an opening (22a) of the high temperature chamber (22) communicating with the exhaust port (2a).   The sub-valve (31) has the annular passage (35) opened to the high temperature chamber (22) when the cylindrical portion (32) closes the low temperature chamber (24), and the guide blade ( The annular passage (35) opens into the low temperature chamber (24) when the upper end (33b) of 33) closes the high temperature chamber (22). A valve device for an internal combustion engine.   The said cylinder part (32) and the said guide blade (33) of the said subvalve (31) are integrally attached to the subvalve stem (34) which act | operates the said subvalve. 4. The valve device for an internal combustion engine according to any one of 3 above.   The cylindrical portion (32) of the sub-valve (31) is tapered so that the inner lower portion (32b) smoothly communicates with the exhaust port (2a). The valve device for an internal combustion engine according to any one of the above.   The cylinder part (32) of the sub-valve (31) has a lower end part (32c) of the inner lower part (32b) bent outward and expanded in diameter, and the tip part can close the cold chamber (24). The valve device for an internal combustion engine according to claim 5, wherein the valve device is provided.   The guide wing (33) is discharged from the upper end opening of the cylindrical portion (32) with the side facing the upper end opening of the cylindrical portion (32) being a guide surface (33c) having a smooth curved surface. The valve device for an internal combustion engine according to any one of claims 1 to 6, wherein combustion gas is smoothly guided to the high temperature chamber (22) and the low temperature chamber (24).   The internal combustion engine according to any one of claims 1 to 7, wherein the cylindrical portion (32), the guide vane (33), and the auxiliary valve stem (34) are integrally formed by precision casting. Valve device.

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