Internal combustion engine, especially large diesel engine

Abstract

Internal combustion engine with at least a first and a second cooling circuit (31, 32), with at least one individual cylinder (1) with a cylinder housing (2) accommodating a cylinder liner (3), and with at least one individual cylinder head (4), wherein the cylinder liner (3) is surrounded by at least one cooling jacket (5, 6) which is fluidically connected to at least one cooling chamber (14) in the individual cylinder head (4), the cylinder liner (3) is surrounded by a first and a second cooling jacket (5, 6), wherein the first cooling jacket (5) is fluidically separated from the second cooling jacket (6) within the cylinder housing (2), characterized in that the first cooling jacket (5) is fluidically connected to at least one first cooling chamber (14) and the second cooling jacket (6) is fluidically connected to at least one second cooling chamber (24) in the individual cylinder head (4).

Description

[0001] The invention relates to an internal combustion engine with at least a first and a second cooling circuit, with at least one individual cylinder with a cylinder housing accommodating a cylinder liner, and with at least one individual cylinder head, wherein the cylinder liner is surrounded by at least one cooling jacket which is fluidically connected to at least one cooling chamber in the individual cylinder head, the cylinder liner being surrounded by a first and a second cooling jacket, wherein the first cooling jacket is fluidically separated from the second cooling jacket within the cylinder housing.

[0002] DE 10 2004 047 452 A1 discloses a cooling system for an internal combustion engine with a first cooling circuit of a cylinder head and a second cooling circuit of an engine block, which are connected to each other. A controllable actuator for regulating the distribution of a coolant flow is provided between the first and second cooling circuits.

[0003] A similar cooling system with a first cooling circuit for cooling the cylinder head and a second cooling circuit for cooling the cylinder block is known from EP 1 035 306 A2.

[0004] DE 10 2004 024 289 A1 describes a cooling system for a vehicle with a high-temperature circuit and a low-temperature circuit. The high-temperature circuit is intended for cooling the internal combustion engine, while the low-temperature circuit serves to cool an intercooler and, if applicable, an oil cooler.

[0005] Also known from DE 10 2011 101 337 A1 is a circuit arrangement with a low-temperature circuit for cooling auxiliary units of an internal combustion engine and a high-temperature circuit for cooling the internal combustion engine and other auxiliary units.

[0006] JP H06-60 745 U discloses an internal combustion engine with at least one cylinder, a cylinder housing accommodating a cylinder liner, and a cylinder head. The cylinder liner is surrounded by a first cooling jacket, and a second cooling jacket arranged in the cylinder liner is fluidly connected to a cooling chamber in the cylinder head. The first cooling jacket is fluidly separated from the second cooling jacket within the cylinder housing. A connection between the first cooling chamber and a cooling chamber in the cylinder head is not provided. Similar internal combustion engines are also known from JP S55-057614 A or JP S58-65927 A.

[0007] JP S58-37 920 U discloses an internal combustion engine with a cylinder block and a cylinder head. An oil-filled oil jacket is integrated into the cylinder block. The oil jacket communicates with an oil chamber in the cylinder head. A water-filled water jacket is also integrated into the cylinder block. The cylinder head also has water-filled water chambers. A connection between the water jacket of the cylinder block and the water chambers of the cylinder head is not provided.

[0008] DE 25 14 592 A1 describes an internal combustion engine with a liquid-cooled single-cylinder head with a cooling chamber connected to a cooling jacket in the cylinder block via a coolant inlet opening. For cooling a receiving sleeve for a central injection valve, an axial connecting channel is provided, which is connected to a cooling chamber in the cylinder head via a radial connecting channel. A similar arrangement is known from DE 28 25 298 A1.

[0009] Furthermore, it is known to use a separate cooling circuit for cooling valve seat rings in large engines.

[0010] Based on the requirement to operate today's large engines with ever-increasing efficiency and lower emissions, it is necessary to adapt the intermediate pressure and ignition pressure potentials of internal combustion engines to the improved turbocharging technology (two-stage turbocharging). This means that more heat must be dissipated in the area of ​​the cylinder liner and the cylinder head fire deck than before.

[0011] The object of the invention is to improve heat dissipation in the area of ​​the fire blanket and the cylinder liner in large engines.

[0012] According to the invention, this is achieved in that the first cooling jacket is fluidly connected to at least one first cooling chamber and the second cooling jacket is fluidly connected to at least one second cooling chamber in the individual cylinder head.

[0013] In order to achieve effective cooling of the top land ring of the cylinder liner, it is advantageous if the first cooling jacket is fluidly connected via at least one, preferably annular, first flow transition within the cylinder housing to at least one, preferably annular, first cooling channel surrounding the top land region of the cylinder liner. The first cooling channel is preferably arranged at least partially, preferably predominantly, between the first cooling jacket and the individual cylinder head. This enables excellent cooling of the cylinder in the top land ring region, in particular if the cylinder liner has at least one radial

[0014] blind hole, radial through hole or preferably tangential milling.

[0015] The first cooling channel is fluidly connected to the first cooling chamber in the individual cylinder head via at least one first transfer opening between the cylinder housing and the individual cylinder head.

[0016] The first cooling jacket can be formed partially by the cylinder housing surrounding the cylinder liner, and partially by the cylinder liner itself, with the second cooling jacket preferably being formed by the individual cylinder housing. Particularly good cooling of the top land ring area is also achieved when the second cooling jacket essentially surrounds the first cooling channel.

[0017] In order to optimally cool the area of ​​the fire cover of the individual cylinder head independently of the cylinder housing, it is provided within the scope of the invention that the second cooling jacket is fluidly connected to at least one second cooling chamber in the individual cylinder head via at least one preferably annular second overflow opening between the cylinder housing and the individual cylinder head.

[0018] The second cooling chamber preferably has at least one annular second cooling channel surrounding a valve seat ring and at least one axial connecting channel adjacent to a central component opening into the combustion chamber, preferably an injector, as well as radial connecting channels between second and third cooling channels and radial connecting bores leading to the second cooling channels or axial connecting channels in the fire deck of the individual cylinder head, wherein preferably the components of the second cooling chamber are arranged at least predominantly in a normal plane to the cylinder axis in the fire deck of the individual cylinder head.

[0019] Furthermore, it can be provided that the axial connecting channel is flow-connected to at least one partial cooling chamber arranged between the first and second cooling chambers in the individual cylinder head, which partial cooling chamber preferably surrounds at least one inlet and / or outlet channel, wherein the partial cooling chamber is separated from the first cooling water chamber by an intermediate deck, and wherein the partial cooling chamber is flow-connected to the first cooling water chamber via at least one second flow transition in the intermediate deck.

[0020] To enable precisely defined heat dissipation in the area of ​​the central component, it is advantageous to form an annular gap between the intermediate deck and the central component, or a sleeve accommodating the central component. An annular aperture is arranged in the gap, preferably the annular aperture being firmly connected to the sleeve. The aperture can be made of metal or plastic.

[0021] The cooling system with the two cooling circuits is thus integrated into the castings of the cylinder housing or the individual cylinder head.

[0022] In principle, the two cooling circuits can be operated at the same temperature.

[0023] However, it is particularly advantageous if the two cooling circuits have different temperature levels, wherein the first cooling circuit is designed as a high-temperature circuit and the second cooling circuit is designed as a low-temperature circuit, wherein the low-temperature circuit has a lower temperature level than the high-temperature circuit.

[0024] The high-temperature circuit is formed by the first cooling circuit, which has an inlet temperature into the first coolant jacket of approximately 85°C. The coolant flows around the cylinder liner in the upper area to adequately cool the fire land ring area and the piston ring area in the area of ​​the first piston ring groove, and then flows through the first transfer opening into the first cooling chamber of the individual cylinder head.

[0025] The second cooling circuit forms the low-temperature circuit, whose temperature is regulated so that the inlet temperature into the second cooling jacket is approximately 50° to 70°C. The coolant flows through the fire deck in the individual cylinder head in a normal plane essentially perpendicular to the cylinder axis. The cooling bores and cooling channels are located very close to the combustion chamber roof of the individual cylinder head and also supply the valve seat inserts of the intake and exhaust valves with coolant. The flow is directed towards the center of the individual cylinder head, is deflected in the area of ​​the injector sleeve by means of an orifice plate, and then flows radially outwards through the lower cooling chamber of the individual cylinder head in the opposite direction to the connecting bores.The flows of the first cooling circuit and the second cooling circuit are specifically combined in the area of ​​the upper first cooling chamber and then exit the cylinder head together at the opening to the water collection line. The coolant of the second cooling circuit can be taken from the first cooling circuit. The arrangement of at least one mixing valve between the first cooling circuit and the second cooling circuit (before entering the cooling jackets of the cylinder housing) enables mixing of the two cooling circuits. This allows, for example, warm water from the first cooling circuit to be mixed with the second cooling circuit when the engine is cold or idling, whereby the mixing valve can be controlled depending on the temperature.

[0026] Because two separate cooling circuits are provided in the cylinder housing and the two separate cooling flow guides in the individual cylinder head, areas of the fire land, the fire blanket and around the inlet and outlet ports in the individual cylinder head can be cooled separately and specifically with the optimal coolant temperature.

[0027] The invention is explained in more detail below with reference to the figures. They show: Fig. 1 shows an internal combustion engine according to the invention in a longitudinal section in a first embodiment; Fig. 2 this internal combustion engine in a meridian section; Fig. 3 an internal combustion engine according to the invention in a second embodiment in a meridian section; Fig. 4 this internal combustion engine in a section along the line IV-IV in Fig. 3; Fig. 5 this internal combustion engine in a section along the line VV in Fig. 3; and Fig. 6 the cooling system of the internal combustion engine according to the invention.

[0028] The internal combustion engine has several individual cylinders 1, each individual cylinder 1 having a cylinder housing 2 and a cylinder liner 3. The cylinder housing 2 is closed at the top by an individual cylinder head 4.

[0029] The cylinder liner 3 is surrounded by a first cooling jacket 5 and a second cooling jacket 6, wherein the first cooling jacket 5 and second cooling jacket 6 belong to different cooling circuits 31, 32 and are separated within the cylinder housing 2, so that the cooling media are supplied separately to the individual cylinder head 4. The first cooling jacket 5 originates from a first supply channel 5a of the first cooling circuit 31, and the second cooling jacket 6 originates from a second supply channel 6a of the second cooling circuit 32. The first cooling jacket 5 surrounds the cylinder liner 3 and is in flow connection via an annular first flow transition 7 with an annular first cooling channel 8 and tangential milled recesses 9 or radial blind bores or radial through bores in the cylinder liner 3 for cooling the fire land ring area 10.A transfer channel 11 extends from the annular first cooling channel 8 and opens into the first cooling chamber 14 via a first transfer opening 12 and a riser channel 13 formed substantially parallel to the cylinder axis 1a. The annular first channel region 8 is surrounded by the second cooling jacket 6, which is formed into the cylinder housing 2. The second cooling jacket 6 is fluidly connected via a second transfer channel 15 and at least one, for example, annular second transfer opening 16 between the cylinder housing 2 and the individual cylinder head 4, as well as radial first connecting bores 17 to annular second cooling channels 18 for cooling the valve seat rings 43. The second cooling channels 18 are connected via radial connecting channels 19 to at least one axial connecting channel 20, which is arranged in the direction of the cylinder axis 1a adjacent to a sleeve 21 for receiving a central component, for example an injection nozzle.Furthermore, the second cooling jacket 6 is connected to at least one axial connecting channel 20 via radial second connecting bores 22. The second cooling channels 18 and the first and second connecting bores 17 and 22 are arranged essentially in a normal plane ε in the fire deck 23 of the individual cylinder head 4 and, together with the axial connecting channels 20, form the second cooling chamber 24 fed by the second cooling circuit 32.

[0030] The axial connecting channels 20 are connected to a lower partial cooling chamber 25, which is separated from the first cooling chamber 14 located above by an intermediate deck 26. The partial cooling chamber 25 is connected to the first cooling chamber 14 via a second flow transition 27.

[0031] The axial and radial connecting channels 19, 20 are preferably formed by bores.

[0032] An annular gap 28 is formed between the intermediate deck 26 and the sleeve 21, into which an annular aperture 29 made of metal or plastic is inserted. The aperture 29 can be firmly attached to the sleeve 21, for example, welded or glued.

[0033] In Fig.6 schematically shows the coolant system 30 of the internal combustion engine. The coolant system 30 has a first cooling circuit 31 and a second cooling circuit 32, wherein the first cooling circuit 31 is designed as a high-temperature circuit HT and the second cooling circuit 32 is designed as a low-temperature circuit NT. A first coolant pump 33 is arranged in the first cooling circuit 31, and a second coolant pump 34 is arranged in the second cooling circuit 32. The coolant of the first cooling circuit 31 flows from the first coolant pump 33 to a first charge air cooler 35 designed as a high-temperature charge air cooler, and from there reaches the first cooling jacket 5 of the cylinder housing 2. The coolant of the second cooling circuit 32 is pumped by the second coolant pump 34 to the second charge air cooler 36 designed as a low-temperature charge air cooler, from which it is fed via the oil cooler 37 to the second cooling jacket 6.The coolant flows through the cooling chambers of the cylinder housing 2 and the individual cylinder head 4 in the manner described above, with the flows of the two cooling circuits 31, 32 merging in the individual cylinder head 4 and leaving the individual cylinder head 4 again via a common coolant manifold 38. The coolant enters a central system cooler 40 via a thermostatic valve 39. Downstream of the system cooler 40, the coolant flows are divided into the two partial flows of the first cooling circuit 31 and the second cooling circuit 32.

[0034] Cooling circuit 31 operates at approximately 85°C (inlet temperature into the first cooling jacket 5), with the coolant flowing around the upper area of ​​the cylinder liner 3 to sufficiently cool the top land ring area 10 and the area of ​​the first groove 9 of the piston ring area. The coolant from the first cooling circuit 31 then flows into the individual cylinder head 4 in the area of ​​the first transfer opening 12.

[0035] The temperature of the second cooling circuit 32 is regulated such that the inlet temperature into the second cooling jacket 6 lies in the range between 50°C and 70°C. The coolant of the second cooling circuit 32 flows through the fire deck 23 of the individual cylinder head 4 essentially in a normal plane ε to the cylinder axis 1a. The second cooling channels 18 and distributor bores 17 and 22 are arranged in the region of a normal plane ε to the cylinder axis 1a near the combustion chamber roof of the individual cylinder head 4 and cool the valve seat rings 43 of the intake and exhaust valves. The flow is directed radially toward the center of the individual cylinder head 4, is deflected in the region of the sleeve 21 by means of the orifice plate 29, and flows through the lower partial cooling chamber 25 in the opposite direction to the distributor bores 17 and 22.The flows of the first and second cooling circuits 31, 32 are specifically combined in the area of ​​the upper first cooling chamber 14 and then exit the individual cylinder head 4 together through the manifold 38. The second cooling circuit 32 can branch off from the low-temperature cooling circuit NT before entering the second coolant jacket 6. The arrangement of the mixing valve 41 between the first and second cooling circuits 31, 32 enables mixing of both cooling circuits 31, 32. For example, when the internal combustion engine is cold or idling, warm water from the high-temperature circuit HT can be mixed into the low-temperature circuit NT. The mixing valve 41 and the control valve 42 can be controlled depending on the temperature.

Claims

[1] Internal combustion engine with at least a first and a second cooling circuit (31, 32), with at least one individual cylinder (1) with a cylinder housing (2) receiving a cylinder liner (3), and with at least one individual cylinder head (4), wherein the cylinder liner (3) is surrounded by at least one cooling jacket (5, 6) which is fluidically connected to at least one cooling chamber (14) in the individual cylinder head (4), the cylinder liner (3) is surrounded by a first and a second cooling jacket (5, 6), wherein the first cooling jacket (5) is fluidically separated from the second cooling jacket (6) within the cylinder housing (2), characterized by that the first cooling jacket (5) is fluidly connected to at least one first cooling chamber (14) and the second cooling jacket (6) is fluidly connected to at least one second cooling chamber (24) in the individual cylinder head (4). [2] Internal combustion engine according to claim 1, characterized bythat the first cooling jacket (5) is fluidly connected via at least one first flow transition (7) within the cylinder housing (2) to at least one first cooling channel (8) surrounding the top land region (10) of the cylinder liner (3). [3] Internal combustion engine according to claim 2, characterized by that the first flow transition (7) and / or the first cooling channel (8) is / are annular. [4] Internal combustion engine according to claim 2 or 3, characterized by that the first cooling channel (8) is arranged at least partially between the first cooling jacket (5) and the individual cylinder head (4). [5] Internal combustion engine according to one of claims 2 to 4, characterized by that the cylinder liner (3) has at least one radial blind bore, through bore or milled recess (9) extending from the first cooling channel (8). [6] Internal combustion engine according to one of claims 2 to 5, characterized bythat the first cooling channel (8) is fluidly connected to the first cooling chamber (14) in the individual cylinder head (4) via at least one first transfer opening (12) between the cylinder housing (2) and the individual cylinder head (4). [7] Internal combustion engine according to one of claims 1 to 6, characterized by that the first cooling jacket (5) is formed partly by the cylinder housing (2) and partly by the cylinder liner (3). [8] Internal combustion engine according to one of claims 1 to 7, characterized by that the second cooling jacket (6) is formed by the cylinder housing (2). [9] Internal combustion engine according to one of claims 2 to 8, characterized by that the second cooling jacket (6) substantially surrounds the first cooling channel (8). [10] Internal combustion engine according to one of claims 1 to 9, characterized bythat the second cooling jacket (6) is fluidly connected to at least one second cooling chamber (24) in the individual cylinder head (4) via at least one second overflow opening (16) between the cylinder housing (2) and the individual cylinder head (4). [11] Internal combustion engine according to claim 10, characterized by that the second overflow opening (16) is annular. [12] Internal combustion engine according to one of claims 1 to 11, characterized by that the second cooling chamber (24) has at least one annular second cooling channel (18) surrounding a valve seat ring (43). [13] Internal combustion engine according to one of claims 1 to 12, characterized by that the second cooling chamber (24) has at least one axial connecting channel (20). [14] Internal combustion engine according to claim 13, characterized by that the axial connecting channel (20) is formed parallel to the cylinder axis (1a). [15] Internal combustion engine according to claim 13 or 14, characterized bythat the axial connecting channel (20) is formed adjacent to a central component opening into the combustion chamber of the individual cylinder (1) or to a sleeve (21) receiving the latter. [16] Internal combustion engine according to claim 15, characterized by that the axial connecting channel (20) is fluidly connected to at least one second cooling channel (18) via at least one radial connecting channel (19). [17] Internal combustion engine according to one of claims 1 to 16, characterized by that the second cooling chamber (24) has at least one radial connecting bore (17, 22) in the fire deck (23) of the individual cylinder head (4). [18] Internal combustion engine according to claim 17, characterized by that at least one connecting bore (17, 22) opens into the second cooling channel (18) or the axial connecting channel (20). [19] Internal combustion engine according to one of claims 12 or 16 to 18, characterized bythat at least one element from the group of connecting bore (17, 22), radial connecting channel (19) and second cooling channel (18) is arranged in a normal plane (ε) to the cylinder axis (1a) in the fire deck (23) of the individual cylinder head (4). [20] Internal combustion engine according to one of claims 13 to 19, characterized by that the axial connecting channel (20) is fluidly connected to at least one partial cooling chamber (25) arranged between the first and second cooling chambers (14, 24) in the individual cylinder head (4). [21] Internal combustion engine according to claim 20, characterized by that the partial cooling chamber (25) surrounds at least one inlet and / or outlet channel. [22] Internal combustion engine according to claim 20 or 21, characterized by that the partial cooling chamber (25) is separated from the first cooling chamber (14) by an intermediate deck (26). [23] Internal combustion engine according to claim 22, characterized bythat the partial cooling chamber (25) is fluidly connected to the first cooling chamber (14) via at least one second flow transition (27) in the intermediate deck (26). [24] Internal combustion engine according to one of claims 22 or 23, characterized by that an annular gap (28) is formed between the intermediate deck (26) and the central component, or a sleeve (21) receiving the central component. [25] Internal combustion engine according to claim 24, characterized by that an annular aperture (29) is arranged in the annular gap (28). [26] Internal combustion engine according to claim 25, characterized by that the annular aperture (29) is firmly connected to the sleeve (21). [27] Internal combustion engine according to claim 25 or 26, characterized by that the aperture (29) is formed by a metal or plastic ring. [28] Internal combustion engine according to one of claims 1 to 27, characterized bythat the first cooling jacket (5) is connected to the first cooling circuit (31) and the second cooling jacket (6) is connected to the second cooling circuit (32). [29] Internal combustion engine according to claim 28, characterized by that the first cooling jacket (5) is connected to the first cooling circuit (31) and the second cooling jacket (6) is connected to the second cooling circuit (32) on the inlet side. [30] Internal combustion engine according to one of claims 1 to 29, characterized by that the first cooling circuit (31) is designed as a high-temperature circuit (HT) and the second cooling circuit (32) is designed as a low-temperature circuit (NT). [31] Internal combustion engine according to claim 30, characterized by that a first coolant pump (33) and a first charge air cooler (35) are arranged in the first cooling circuit (31), wherein the low-temperature circuit (NT) has a lower temperature level than the high-temperature circuit (HT). [32] Internal combustion engine according to one of claims 1 to 31, characterized bythat a second coolant pump (34) and a second charge air cooler (36), preferably also an oil cooler (37), are arranged in the second cooling circuit (32). [33] Internal combustion engine according to one of claims 1 to 32, characterized by that the first and second cooling circuits (31, 32) can be connected to one another via at least one bypass or mixing valve (41, 42) before entering the first or second cooling jacket (5, 6) of the cylinder housing (2). [34] Internal combustion engine according to one of claims 1 to 33, characterized by that the media of the first and second cooling circuits (31, 32) are brought together within the individual cylinder head (4). [35] Internal combustion engine according to one of claims 1 to 34, characterized by that the first and second cooling circuits (31, 32) branch off from a common cooling circuit downstream of a central cooler (40). [36] Internal combustion engine according to one of claims 1 to 30 or 32 to 35, each not dependent on claim 31, characterized by that the first and second cooling circuits (31, 32) have the same temperature level before entering the first and second cooling jackets (5, 6), respectively.

Images