internal combustion engine

Abstract

Internal combustion engine, including: a crankcase for rotatable mounting of a crankshaft about a crankshaft longitudinal axis (L_longitudinal), wherein the crankcase comprises a crankcase water jacket (5), a cylinder head connected to the crankcase and comprising a cylinder head water jacket (18), and a coolant pump for supplying the crankcase water jacket (5) and the cylinder head water jacket (18) with a coolant flow rate, wherein the crankcase water jacket (5) and the cylinder head water jacket (18) are fluidically connected in series, wherein the crankcase water jacket (5) can be supplied with the coolant volume flow from the coolant pump via a crankcase inlet (6), and the crankcase water jacket (5) is designed such that the coolant volume flow is directed via a crankcase outlet (11) and transferred towards the cylinder head water jacket (18), and the crankcase inlet (6) and the crankcase outlet (11) are axially spaced apart, characterized by that the crankcase inlet (6) is arranged on a first longitudinal side of the crankcase and that the crankcase drain (11) is located on a second longitudinal side of the crankcase.

Description

[0001] The present invention relates to an internal combustion engine with a crankcase water jacket and a cylinder head water jacket which are fluidically connected to each other.

[0002] Internal combustion engines are subject to high thermal stress in the crankcase and cylinder head areas. To reduce this thermal stress, modern internal combustion engines are water-cooled. For this purpose, internal combustion engines can have a water jacket, consisting of a crankcase water jacket and a cylinder head water jacket. The integration of the water jacket into the crankcase and cylinder head, respectively, is typically achieved during the casting process of the components by inserting casting cores.

[0003] From JP 2017-125 445 A, an internal combustion engine with a water jacket is known, which includes a crankcase water jacket. The crankcase water jacket is supplied with coolant via a crankcase inlet by a coolant pump located on one end face of the crankcase.

[0004] From DE 10 2015 014 514 A1, an internal combustion engine with a water jacket is known. The water jacket comprises a crankcase water jacket and a cylinder head water jacket, which are fluidically connected in series. The crankcase water jacket is supplied with a coolant flow from an inlet rail. Within the crankcase water jacket, the coolant flow is divided among a plurality of outlets. At each of these outlets, a portion of the coolant flow is transferred directly through the cylinder head gasket to the cylinder head water jacket. This design has the disadvantage that the transfer between the crankcase water jacket and the cylinder head water jacket is space-intensive and prevents the integration of additional functional sections into the water jacket.

[0005] Based on this, the present invention aims to provide an internal combustion engine that includes a space-optimized water jacket and enables the integration of further functional sections into the water jacket.

[0006] To solve the problem underlying the invention, an internal combustion engine with the features of claim 1 is proposed. Exemplary embodiments of the invention are set forth in the dependent claims.

[0007] In the internal combustion engine according to the invention, the coolant flow rate supplied by the coolant pump is thus completely discharged from the crankcase water jacket through the crankcase drain, whereby the entire coolant flow rate has previously passed through the crankcase water jacket at least lengthwise. The resulting single outlet of the crankcase water jacket creates free installation space in the internal combustion engine, which can be used, for example, for the integration of further functional sections of the water jacket.

[0008] By locating the crankcase drain on a second longitudinal side of the crankcase, the entire coolant flow can be passed through the crankcase water jacket not only longitudinally but also transversely. This resulting complete longitudinal / transverse flow through the crankcase allows for efficient cooling.

[0009] In one possible embodiment of the internal combustion engine, the crankcase can comprise a first cylinder bore and a second cylinder bore, separated from each other axially by a cylinder web. The crankcase inlet can be located axially on a first side of the cylinder web, and the crankcase outlet on a second side of the cylinder web opposite the first.

[0010] In another possible embodiment of the internal combustion engine, the crankcase can comprise a series of cylinder bores, wherein the first cylinder bore defines the series as a first cylinder end bore and the second cylinder bore as a second cylinder end bore. The first cylinder bore and the second cylinder bore can each be arranged axially, that is, in a direction parallel to the longitudinal axis of the crankshaft, at least partially between the crankcase inlet and outlet.

[0011] In another possible embodiment of the internal combustion engine, the cylinder head water jacket can be supplied with at least a portion of the coolant flow from the coolant pump via the crankcase water jacket and a cylinder head inlet. The coolant flow can be transferred to the coolant pump via a coolant pump inlet. The cylinder head inlet can be located on the second longitudinal side and the coolant pump inlet on the first longitudinal side of the crankcase.

[0012] The cylinder head inlet can also be arranged axially spaced from the coolant pump inlet. The crankcase inlet can be arranged axially between the coolant pump inlet and the crankcase outlet. The first cylinder bore and the second cylinder bore can each be arranged axially, at least partially, between the crankcase outlet and the cylinder head inlet.

[0013] In one possible embodiment of the internal combustion engine, the crankcase outlet and the cylinder head inlet can be fluidically connected via a longitudinal channel located in the crankcase. An oil heat exchanger can be arranged in an oil heat exchanger recess within this longitudinal channel.

[0014] In another possible embodiment of the internal combustion engine, the crankcase inlet can open into a crankcase distribution channel. The crankcase distribution channel can be located on the first longitudinal side of the crankcase. A crankcase collection channel, located on the second longitudinal side of the crankcase, can open into the crankcase outlet. The crankcase distribution channel and the crankcase collection channel can be fluidically connected to each other via at least one cylinder bore channel. The width of the crankcase distribution channel can decrease axially away from the crankcase inlet. The width of the crankcase collection channel can increase axially towards the crankcase outlet.

[0015] In another possible embodiment of the internal combustion engine, the cylinder head inlet can open into a cylinder head distribution channel. The cylinder head distribution channel can be located on the second longitudinal side of the crankcase. A cylinder head collector channel, located on the first longitudinal side of the crankcase, can open into the coolant pump inlet. The cylinder head distribution channel and the cylinder head collector channel can be fluidically connected to each other via at least one cylinder head transverse channel.

[0016] The width of the cylinder head distributor channel can decrease axially away from the cylinder head inlet. The width of the cylinder head collector channel can increase axially towards the coolant pump inlet.

[0017] The crankcase distributor channel can be located between the cylinder head manifold and a plane defined by a cylinder head gasket within the crankcase. The crankcase manifold can also be located between the longitudinal channel and a plane defined by a cylinder head gasket within the crankcase.

[0018] One possible embodiment of the internal combustion engine according to the invention is explained below with reference to the figure drawings.

[0019] This shows Fig. 1 a first perspective view of the water jacket of an internal combustion engine according to the invention; Fig. 2 a second perspective view of the water jacket of the internal combustion engine from Fig. 1; Fig. 3 a perspective view of the crankcase water jacket of the internal combustion engine Fig. 1 together with the longitudinal channel, Fig. 4 a top view of the crankcase water jacket Fig. 3; Fig. 5 a perspective view of the cylinder head distributor channel and the cylinder head collector channel, and Fig. 6 a top view of the cylinder head distributor channel and the cylinder head collector channel from Fig. 5.

[0020] The Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. Figures 6, which are described together below, show the water jacket 1 of an internal combustion engine according to the invention. The water jacket 1 is represented in the figures in a manner known to those skilled in the art by the cast cores used. The internal combustion engine according to the invention has a longitudinal axis L_longitudinal, which is defined by the crankshaft axis of the internal combustion engine. In the present case, the internal combustion engine is designed as an inline four-cylinder engine, with a first cylinder bore 12, a second cylinder bore 15, a third cylinder bore 13, and a fourth cylinder bore 14. The first cylinder bore 12 delimits the cylinder bank on a first side and can therefore be referred to as the first cylinder end bore. The second cylinder bore 15 delimits the cylinder bank on a second side and can therefore be referred to as the second cylinder end bore. The cylinder bores 12, 13, 14, and 15 each have parallel cylinder bore axes.

[0021] In Fig. In the respective cylinder bores, cylinder casting cores are indicated by dashed circles. It is thus evident that the first cylinder bore 12 and the third cylinder bore 13 are separated from each other by a first cylinder web 26, the third cylinder bore 13 and the fourth cylinder bore 14 by a second cylinder web 27, and the fourth cylinder bore 14 and the second cylinder bore 15 by a third cylinder web 28.

[0022] The water jacket 1 comprises a crankcase water jacket 5, which is arranged in the crankcase of the internal combustion engine, and a cylinder head water jacket 18, which is arranged in the cylinder head of the internal combustion engine. The crankcase and the cylinder head of the internal combustion engine are sealed against each other in a known manner by a cylinder head gasket (not shown). The cylinder head gasket includes passages that allow a fluidic connection between the crankcase water jacket 5 and the cylinder head water jacket 18.

[0023] The water jacket 1 of the internal combustion engine forms a circuit through which coolant flows from a coolant pump (not shown). The crankcase water jacket 5 and the cylinder head water jacket 18 are arranged in series. Thus, the coolant flows first through the crankcase water jacket 5, starting from the coolant pump, before the coolant subsequently flows through the cylinder head water jacket 18. The flow pattern of the coolant is unambiguously clear to a person skilled in the art from the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. 6, where the coolant flow is indicated by arrows. For clarity, the coolant flow between the coolant pump and the initial entry into the cylinder head water jacket 18 is shown with dashed arrows, and the flow between the initial entry of the coolant into the cylinder head water jacket 18 and the re-entry of the coolant into the coolant pump is shown with dashed arrows.

[0024] The crankcase water jacket 5 is formed by a crankcase main core 29. A core for a longitudinal channel 16, a core for a cylinder head distributor channel 20, and a core for a cylinder head collector channel 23 are also arranged in the crankcase.

[0025] The cylinder head water jacket 18 is formed by a cylinder head main core 30.

[0026] The cylinder head core 30 comprises a section 2 for accommodating the coolant pump (not shown), a thermostat channel section 3 in which a thermostat for regulating the coolant flow can be arranged and which forms the inlet to an external cooler, and a suction channel section 4, which supplies the suction side of the coolant pump with coolant and is fluidically connected to the external cooler. It is also conceivable that section 2, the thermostat channel section 3, and the suction channel section 4 could be implemented in a separate core, which could be located, for example, in the crankcase or a separate console.

[0027] The main crankcase core 29 has a crankcase inlet 6, which is fluidically connected to the pressure side of the coolant pump via a passage in the cylinder head gasket. The crankcase inlet 6 opens into a crankcase distribution channel 7. The crankcase distribution channel 7 tapers, at least in sections, from the crankcase inlet 6 along the longitudinal axis L_ of the internal combustion engine. The main crankcase core 29 also has a crankcase collector channel 10, which is fluidically connected to the crankcase distribution channel 7 via three channel sections 8, a first end-face channel 9, and a second end-face channel 9'. A first channel section 8 extends through the first cylinder land 26, a second channel section 8' extends through the second cylinder land 27, and a third channel section 8" extends through the third cylinder land 28.The first end-face channel 9 extends through a first end wall of the crankcase and the second end-face channel extends through a second end wall of the crankcase.

[0028] The crankcase collector channel 10 opens into a crankcase drain 11 and widens, at least in sections, along the longitudinal axis L_longitudinal in the direction of the crankcase drain 11. In this case, the crankcase water jacket 5 forms a closed system in the area between the crankcase inlet 6 and the crankcase drain 11. Thus, a coolant flow rate delivered by the coolant pump to the crankcase inlet 6 is completely routed through the crankcase drain 11.

[0029] The crankcase inlet 6 and the crankcase outlet 11 are arranged longitudinally spaced apart from each other along the longitudinal axis L_. The cylinder bores 12, 13, 14, 15 of the internal combustion engine are arranged at least partially between the crankcase inlet 6 and the crankcase outlet 11 in the direction of the longitudinal axis L_. In this case, the third cylinder bore 13 and the fourth cylinder bore 14 are arranged completely between the crankcase inlet 6 and the crankcase outlet 11. The first cylinder bore 12 is radially overlapped with the crankcase inlet 6 at least partially in the direction of the longitudinal axis L_. The second cylinder bore 15 is radially overlapped with the crankcase outlet 11 at least partially in the direction of the longitudinal axis L_.This arrangement of crankcase inlet 6 and crankcase outlet 11 ensures that the crankcase is completely permeated by the coolant flow in the longitudinal direction.

[0030] The crankcase inlet 6 is located on the first longitudinal side of the crankcase, where the coolant pump is also located. The crankcase outlet 11 is located on the second longitudinal side of the crankcase, opposite the first longitudinal side. This arrangement of the crankcase inlet 6 and outlet 11 ensures that the coolant flow passes through the crankcase in a direction transverse to the longitudinal axis L_longitudinal. The crankcase is thus subjected to a longitudinal / transverse flow of coolant.

[0031] The crankcase drain 11 opens into a longitudinal channel 16, which is cast into the crankcase. The longitudinal channel 16 extends from the crankcase drain 11 along the longitudinal axis L_longitudinal to a cylinder head inlet 19. In this case, the cylinder head inlet 19 is arranged in radial overlap with the first cylinder bore 12 with respect to the longitudinal axis L_longitudinal.

[0032] Between the crankcase outlet 11 and the cylinder head inlet 19, the longitudinal channel 16 includes a heat exchanger recess 17 in which a heat exchanger, for example a heat exchanger for an oil cooling circuit of the internal combustion engine, can be arranged.

[0033] The cylinder head inlet 19 opens into the cylinder head distribution channel 20. The cylinder head distribution channel 20 is cast into the crankcase. At least a portion of the coolant flow supplied by the coolant pump flows through the cylinder head inlet 19. In particular, the entire coolant flow supplied by the coolant pump can flow through the cylinder head inlet 19. The cylinder head distribution channel 20 extends parallel to the longitudinal axis L_ and terminates axially before the crankcase outlet 11. The crankcase outlet 11 and the cylinder head distribution channel 20 therefore do not intersect. The cylinder head distribution channel 20 is located on, or rather cast into, the second longitudinal side of the crankcase. The cylinder head distribution channel 20 has a central section that extends parallel to the longitudinal axis L_ and tapers towards the longitudinal axis L_, starting from the cylinder head inlet 19.The width of the central section of the cylinder head distributor channel 20 and the width of the crankcase collector channel 10 change in the present case in a direction parallel to the longitudinal axis L_longitudinally in opposite directions.

[0034] In the present case, the cylinder head distributor channel 20 has four transfer sections 21 that extend essentially parallel to the cylinder bore axes. The four transfer sections 21 are uniformly spaced along the longitudinal axis L. Each of the four transfer sections 21 terminates in a transfer opening 31, which interacts with passages in the cylinder head gasket, allowing coolant to transfer from the respective transfer section 21 into the cylinder head water jacket 18.

[0035] The cylinder head water jacket 18 comprises several cylinder head transverse channels 22, which are supplied with coolant from the transfer sections 21 and extend transversely to the longitudinal axis L_. The cylinder head water jacket 18 is designed such that the cylinder head is flowed through by the coolant essentially in one direction transversely to the longitudinal axis L_.

[0036] A cylinder head manifold 23 is arranged on, or rather cast into, the first longitudinal side of the crankcase. The cylinder head manifold 23 comprises four transfer sections 24, which extend essentially parallel to the cylinder bore axes and open into a central section of the cylinder head manifold 23, which extends in the direction of the longitudinal axis L_ along the internal combustion engine. The central section of the cylinder head manifold 23 widens in the direction of the longitudinal axis L_ towards the coolant pump inlet 25. The width of the central section of the cylinder head manifold 23 and the width of the crankcase distributor channel 7 change in the same direction in this case, parallel to the longitudinal axis L_.

[0037] The transfer sections 24 are uniformly spaced along the longitudinal axis L. Each transfer section 24 terminates in a transfer opening 32 which interacts with passages in the cylinder head gasket, allowing coolant to transfer from the cylinder head water jacket 18 into the respective transfer section 24. The central section of the cylinder head manifold 23 opens into a coolant pump inlet 25, through which the coolant is returned past the thermostat and the external radiator to the coolant pump.

[0038] The cylinder head inlet 19 is arranged in the direction of the longitudinal axis L_longitudinally between the coolant pump inlet 25 and the crankcase outlet 11.

[0039] The crankcase distribution channel 7 is arranged in the crankcase, at least sectionally, between the cylinder head manifold 23 and a plane defined by a cylinder head gasket, in a direction parallel to the cylinder bore axes. In the present case, the crankcase distribution channel 7 is arranged between the central section of the cylinder head manifold 23 and the plane defined by a cylinder head gasket in the crankcase. As can be seen in particular from Fig. As can be seen in Figure 2, the crankcase distribution channel 7 has recesses through which the transfer sections 24 of the cylinder head collector channel 23 extend.

[0040] The crankcase collector channel 10 is arranged in the crankcase in a direction parallel to the cylinder bore axes, at least sectionally, between the longitudinal channel 16 and the plane defined by the cylinder head gasket. Reference symbol list 1 Water coat Section 2 for the installation of a coolant pump 3 Thermostat duct section 4 Suction channel section 5 Crankcase water jacket 6 Crankcase inlet 7 Crankcase distributor channel 8 Bridge channel 9 Frontal channel 10 Crankcase collector channel 11 Crankcase drain 12 cylinder bore 13 Cylinder bore 14 cylinder bore 15 cylinder bore 16 Longitudinal channel 17 Heat exchanger recess 18 Cylinder head water jacket 19 Cylinder head inlet 20 Cylinder head distributor channel 21 Handover section 22 Cylinder head cross-channel 23 Cylinder head manifold 24 Transfer section 25 Coolant pump inlet 26 cylinder bridge 27 cylinder bridge 28 cylinder bridge 29 Crankcase main core 30 Cylinder head core L_ Longitudinal crankshaft axis

Claims

[1] Internal combustion engine, comprising: a crankcase for rotatable mounting of a crankshaft about a crankshaft longitudinal axis (L_longitudinal), wherein the crankcase comprises a crankcase water jacket (5), a cylinder head connected to the crankcase and comprising a cylinder head water jacket (18), and a coolant pump for supplying the crankcase water jacket (5) and the cylinder head water jacket (18) with a coolant flow rate, wherein the crankcase water jacket (5) and the cylinder head water jacket (18) are fluidically connected in series, wherein the crankcase water jacket (5) can be supplied with the coolant volume flow from the coolant pump via a crankcase inlet (6), and the crankcase water jacket (5) is designed such that the coolant volume flow is directed via a crankcase outlet (11) and transferred towards the cylinder head water jacket (18), and the crankcase inlet (6) and the crankcase outlet (11) are axially spaced apart, characterized by , that the crankcase inlet (6) is arranged on a first longitudinal side of the crankcase and that the crankcase drain (11) is located on a second longitudinal side of the crankcase. [2] Internal combustion engine according to claim 1, characterized by , that the crankcase comprises a first cylinder bore (12) and a second cylinder bore (15) which are separated from each other in the axial direction by a cylinder web (26, 27, 28), wherein the crankcase inlet (6) is axially located on a first side of the cylinder web (26, 27, 28) and the crankcase outlet (11) is located on a second side opposite the first side of the are arranged on the cylindrical web (26, 27, 28). [3] Internal combustion engine according to claim 1 or 2, characterized by , that the crankcase includes a series of cylinder bores (12, 13, 14, 15), wherein the first cylinder bore (12) limits the series of cylinder bores (12, 13, 14, 15) as a first cylinder end bore and the second cylinder bore (15) as a second cylinder end bore, wherein the first cylinder bore (12) and the second cylinder bore (15) are each arranged in the axial direction at least partially between the crankcase inlet (6) and the crankcase outlet (11). [4] Internal combustion engine according to any one of claims 1 to 3, characterized by , that the cylinder head water jacket (18) is supplied with at least a part of the coolant volume flow by the coolant pump via the crankcase water jacket (5) and a cylinder head inlet (19), and that the coolant volume flow is transferred from the cylinder head water jacket (18) via a coolant pump inlet (25) to the coolant pump, wherein the cylinder head inlet (19) is located on the second longitudinal side and the coolant pump inlet (25) is located on the first longitudinal side of the crankcase. [5] Internal combustion engine according to claim 4, characterized by , that the cylinder head inlet (19) is arranged axially spaced from the coolant pump inlet (25). [6] Internal combustion engine according to one of claims 4 or 5, characterized by, that the first cylinder bore (12) and the second cylinder bore (15) are each arranged at least partially in the axial direction between the crankcase outlet (11) and the cylinder head inlet (19). [7] Internal combustion engine according to any one of claims 4 to 6, characterized by , that the crankcase inlet (6) is arranged in the axial direction between the coolant pump inlet (25) and the crankcase outlet (11). [8] Internal combustion engine according to any one of claims 4 to 7, characterized by , that the crankcase outlet (11) and the cylinder head inlet (19) are fluidically connected via a longitudinal channel (16) in the crankcase, wherein in the longitudinal channel (16) in particular an oil heat exchanger is arranged in an oil heat exchanger recess. [9] Internal combustion engine according to any one of claims 1 to 8, characterized by , that the crankcase inlet (6) opens into a crankcase distribution channel (7) which is arranged on the first longitudinal side of the crankcase; and that a crankcase collecting channel (10), which is arranged on the second longitudinal side of the crankcase, opens into the crankcase drain (11); wherein the crankcase distribution channel (7) and the crankcase collection channel (10) are fluidically connected to each other via at least one cylinder web channel (8). [10] Internal combustion engine according to claim 9, characterized by , that the width of the crankcase distributor channel (7) decreases in the axial direction away from the crankcase inlet (6), and that the width of the crankcase collector channel (10) increases in the axial direction towards the crankcase outlet (11). [11] Internal combustion engine according to any one of claims 1 to 9, characterized by , that the cylinder head inlet (19) opens into a cylinder head distributor channel (20) which is located on the second longitudinal side of the crankcase; that a cylinder head collector channel (23), which is located on the first longitudinal side of the crankcase, opens into the coolant pump inlet (25); wherein the cylinder head distributor channel (20) and the cylinder head collector channel (23) are fluidically connected to each other via at least one cylinder head transverse channel (22). [12] Internal combustion engine according to claim 11, characterized by , that the width of the cylinder head distributor channel (20) decreases in the axial direction away from the cylinder head inlet (19), and / or that the width of the cylinder head manifold (23) increases in the axial direction towards the coolant pump inlet (25). [13] Internal combustion engine according to one of claims 11 or 12, characterized by, that the crankcase distribution channel (7) is arranged in the crankcase between the cylinder head manifold (23) and a plane defined by a cylinder head gasket. [14] Internal combustion engine according to claim 13, characterized by , that the crankcase collector channel (10) is located in the crankcase between the longitudinal channel (16) and the plane defined by the cylinder head gasket.

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