turbocharger

Abstract

To provide a supercharger capable of suppressing a push-out loss.SOLUTION: A supercharger comprises a turbine housing, and a first exhaust passage, a second exhaust passage and a third exhaust passage, which are connected to the turbine housing. The first exhaust passage is connected to a first cylinder of a plurality of cylinders of an internal combustion engine, through which exhaust gas discharged from the first cylinder flows. The second exhaust passage is connected to a second cylinder of the plurality of cylinders, through which exhaust gas discharged from the second cylinder flows. The third exhaust passage is connected to a third cylinder of the plurality of cylinders, through which exhaust gas discharged from the third cylinder flows. The exhaust gas flowing in from the first exhaust passage and the exhaust gas flowing in from the second exhaust passage join inside the turbine housing. The distance from a turbine shaft to the connection position between the first exhaust passage and the turbine housing and the distance from the turbine shaft to the connection position between the second exhaust passage and the turbine housing are greater than the distance from the turbine shaft to the connection position between the third exhaust passage and the turbine housing.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a turbocharger. [Background technology]

[0002] BACKGROUND ART A supercharger that supercharges intake air introduced into an internal combustion engine is known (for example, Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-279680 Summary of the Invention [Problem to be solved by the invention]

[0004] A turbocharger is operated by introducing exhaust gas from multiple cylinders of an internal combustion engine into the turbine of the turbocharger. The exhaust gases discharged from the multiple cylinders join together before being introduced into the turbine. Collision of the exhaust gases at the joining point can increase exhaust gas loss (push-out loss). Therefore, the object of the present invention is to provide a turbocharger that can suppress push-out loss. [Means for solving the problem]

[0005] The above object is achieved by providing an internal combustion engine including a turbine housing, and a first exhaust passage, a second exhaust passage, and two third exhaust passages connected to the turbine housing, the internal combustion engine having one first cylinder, one second cylinder, and two third cylinders, the first cylinder, the two third cylinders, and the second cylinder being arranged in this order, the first exhaust passage being connected to the first cylinder and through which exhaust gas discharged from the first cylinder flows, the second exhaust passage being connected to the second cylinder and through which exhaust gas discharged from the second cylinder flows, and one The third exhaust passage is connected to one of the third cylinders, and exhaust gas discharged from the one third cylinder flows through the third exhaust passage, and the other third exhaust passage is connected to the other third cylinder, and exhaust gas discharged from the other third cylinder flows through the third exhaust passage. The turbine housing has a fourth exhaust passage, a fifth exhaust passage, and a sixth exhaust passage, as well as a flange portion. The one third exhaust passage and the other third exhaust passage join together upstream of the turbine housing to form a seventh exhaust passage. The flange portion The first connection part of In the above, the first exhaust passage is connected to the fourth exhaust passage, and the flange portion The second connection part of In the above, the second exhaust passage is connected to the fifth exhaust passage, and the flange portion The third connection part wherein the seventh exhaust passage is connected to the sixth exhaust passage, and the fourth exhaust passage and the fifth exhaust passage join together, In the flange portion, the first connection portion and the second connection portion are aligned in a first direction, and the third connection portion is provided at a position spaced apart from the first connection portion and the second connection portion in a second direction intersecting the first direction, From the turbine shaft to the flange portion The distance to the first connection portion and the distance to the second connection portion are greater than the distance from the turbine shaft to the third connection portion. This can be achieved by a supercharger.

[0008] The fourth exhaust passage and the fifth exhaust passage The angle between the fourth exhaust passage and the fifth exhaust passage at the joining point may be 90 degrees or less. [Effects of the Invention]

[0009] A turbocharger capable of suppressing extrusion loss can be provided. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a schematic view illustrating a turbocharger according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating a flange portion of a turbine housing. [Figure 3] FIG. 3 is a schematic diagram illustrating a supercharger according to a comparative example. [Figure 4] 4(a) and 4(b) are diagrams illustrating pressure. DETAILED DESCRIPTION OF THE INVENTION

[0011] The turbocharger of this embodiment will be described below with reference to the drawings. However, the dimensions, ratios, etc. of each part in the drawings may not be illustrated to be exactly the same as the actual ones. Furthermore, some details may be omitted in some drawings.

[0012] FIG. 1 is a schematic diagram illustrating a turbocharger 100 according to an embodiment. The turbocharger 100 is provided in an internal combustion engine 10. The internal combustion engine 10 is, for example, a four-cylinder engine having four cylinders #1, #2, #3, and #4. The cylinders #1, #2, #3, and #4 are arranged in a row in this order. Cylinder #1 (first cylinder) is located at one end of the row. Cylinder #4 (second cylinder) is located at the other end of the row. Cylinders #2 and #3 (third cylinders) are located between cylinder #1 and cylinder #4.

[0013] The turbocharger 100 has exhaust passages 20, 22, 24, and 26, and a turbine housing 30. The exhaust passages 20, 22, 24, and 26 are provided in the cylinder head of the internal combustion engine 10.

[0014] The turbine is housed inside the turbine housing 30. The turbine housing 30 is provided with exhaust passages 32, 34, and 36, and a wastegate valve (WGV) 38.

[0015] In the cylinders of the internal combustion engine 10, a mixture of fuel and air is burned, generating exhaust gas. The exhaust gas flows from the cylinders of the internal combustion engine 10 through an exhaust passage into the turbine housing 30 of the turbocharger 100. The exhaust gas blows against the turbine, causing it to rotate. A compressor (not shown) is connected to the turbine and rotates together with the turbine. When the turbocharger 100 is driven, the air is supercharged. When high-pressure air is supplied to the internal combustion engine 10, the output of the internal combustion engine 10 increases.

[0016] The line L1 in FIG. 1 indicates the connection position between the exhaust passages 20, 22, 24, and 26 and the turbine housing 30.

[0017] One end of the exhaust passage 20 (first exhaust passage) is connected to the exhaust port of cylinder #1 of the internal combustion engine 10. The other end of the exhaust passage 20 is connected to the turbine housing 30. The exhaust passage 20 communicates with an exhaust passage 32 (fourth exhaust passage) of the turbine housing 30. The exhaust passage 20 and the exhaust passage 32 form an exhaust passage 33.

[0018] One end of the exhaust passage 26 (second exhaust passage) is connected to the exhaust port of cylinder #4 of the internal combustion engine 10. The other end of the exhaust passage 26 is connected to the turbine housing 30. The exhaust passage 26 communicates with an exhaust passage 36 (fifth exhaust passage) of the turbine housing 30. The exhaust passage 20 and the exhaust passage 36 form an exhaust passage 35.

[0019] The exhaust passage 32 and the exhaust passage 36 join together upstream of the WGV 38 in the turbine housing 30 to form an exhaust passage 37. The angle formed by the exhaust passage 32 and the exhaust passage 36 at the joining point is defined as A1.

[0020] One end of the exhaust passage 22 (third exhaust passage) is connected to the exhaust port of cylinder #2 of the internal combustion engine 10. One end of the exhaust passage 24 (third exhaust passage) is connected to the exhaust port of cylinder #3 of the internal combustion engine 10. The exhaust passage 22 and the exhaust passage 24 merge upstream of the turbine housing 30 to form an exhaust passage 25. The exhaust passage 25 is connected to the turbine housing 30 and communicates with an exhaust passage 34 (sixth exhaust passage) of the turbine housing 30.

[0021] The exhaust passage extends in the form of scrolls, the length of which varies depending on the position, with the outer scroll being longer than the inner scroll.

[0022] 2 is a diagram illustrating the flange portion 40 of the turbine housing 30, illustrating the front of the flange portion 40. The exhaust passages 20, 25, and 26 of the cylinder head are connected to the flange portion 40. The flange portion 40 has three holes 42, 44, and 46. The hole 42 communicates with the exhaust passage 32 and serves as the connection between the exhaust passage 20 and the exhaust passage 32. The hole 44 communicates with the exhaust passage 34 and serves as the connection between the exhaust passage 25 and the exhaust passage 34. The hole 46 communicates with the exhaust passage 36 and serves as the connection between the exhaust passage 26 and the exhaust passage 36.

[0023] The dotted line in Figure 2 represents the turbine shaft 48. The turbine rotates around the shaft 48 as its axis of rotation. Line L2 represents the center of the shaft 48. Line L3 represents the centers (centroids) of the holes 42 and 46. Line L4 represents the centroid of the hole 44. The distance from the shaft 48 to the hole 42 is equal to the distance from the shaft 48 to the hole 46. The distances from the shaft 48 to the hole 42 and from the shaft 48 to the hole 46 are greater than the distance from the shaft 48 to the hole 44. The distance D1 from the center of the shaft 48 to the centroids of the holes 42 and 46 is greater than the distance D2 from the center of the shaft 48 to the centroid of the hole 44.

[0024] As shown in Figure 2, the distance from axis 48 to bore 42 and the distance from axis 48 to bore 46 are greater than the distance from axis 48 to bore 44. Exhaust passages 22, 24, 25, and 34 form the inner scroll. Exhaust passages 33 and 35 form the outer scroll. Therefore, exhaust passages 33 and 36 are longer than exhaust passages 22, 24, and 25.

[0025] The exhaust passage 33 and the exhaust passage 36 merge to form the exhaust passage 35. Because the exhaust passage 33 and the exhaust passage 36 are long, they gradually approach each other until they merge. At the merged position, the angle A1 between the exhaust passage 33 and the exhaust passage 36 becomes small. The angle A1 is, for example, 90 degrees or less, 60 degrees or less, 45 degrees or less, 30 degrees or less, etc.

[0026] (Comparative Example) 3 is a schematic diagram illustrating a turbocharger according to a comparative example. Line L5 indicates the connection position between the exhaust passage and the turbine housing 30. The exhaust passages 20, 22, 24, and 26 join together upstream of the position where they connect to the turbine housing 30, and are connected to the turbine housing 30 downstream of the joining position.

[0027] The exhaust passage 20 is connected to cylinder #1. The exhaust passage 26 is connected to cylinder #4. The two exhaust passages 20 and 26 connected to the cylinders at both ends join together before connecting to the turbine housing 30. Therefore, the exhaust passage 20 and the exhaust passage 26 face each other. The angle A2 formed by the exhaust passage 20 and the exhaust passage 26 is larger than the angle A1 in FIG. 1 and is close to 180 degrees. The exhaust gas flowing through the exhaust passage 20 and the exhaust gas flowing through the exhaust passage 26 collide. The collision of the exhaust gases creates resistance to the exhaust gas being discharged. As a result, the displacement loss increases.

[0028] Figures 4(a) and 4(b) are diagrams illustrating pressure. Figures 4(a) and 4(b) show the pressure in cylinder #1 and exhaust passage 20 during the exhaust stroke. The horizontal axis represents time. The vertical axis represents pressure. The solid line represents the pressure in cylinder #1. The dotted line represents the pressure in exhaust passage 20. Figure 4(a) shows a comparative example. Figure 4(b) shows an embodiment.

[0029] As shown in Figures 4(a) and 4(b), the pressure in cylinder #1 and exhaust passage 20 drops during the exhaust stroke. In the comparative example shown in Figure 4(a), the pressure does not drop easily from time t1 to around t2. This is because the exhaust gas collides with the cylinder and the exhaust passage, making it difficult for the exhaust gas to be discharged. In the embodiment shown in Figure 4(b), the pressure does not stagnate but continues to drop. This is because the exhaust gas collides with the cylinder and the exhaust passage, making it difficult for the exhaust gas to be discharged.

[0030] According to this embodiment, exhaust passage 20 is connected to cylinder #1 and turbine housing 30 and communicates with exhaust passage 32 through hole 42. Exhaust passage 22 is connected to cylinder #2 and turbine housing 30. Exhaust passage 24 is connected to cylinder #3 and turbine housing 30. Exhaust passages 22 and 24 communicate with exhaust passage 34 through hole 44. Exhaust passage 26 is connected to cylinder #4 and turbine housing 30 and communicates with exhaust passage 36 through hole 46. As shown in FIG. 2 , distance D1 from turbine shaft 48 to holes 42 and 46 is greater than distance D2 from shaft 48 to hole 44. Exhaust passages 20 and 32, as well as exhaust passages 26 and 36, form outer scrolls (exhaust passages 33 and 35). Exhaust passages 22, 24, and 25 form inner scrolls.

[0031] The outer scroll is longer than the inner scroll. Exhaust passage 33 and exhaust passage 35 gradually approach each other and merge to form exhaust passage 37. At the merging point, the angle A1 between exhaust passage 33 and exhaust passage 36 becomes smaller. The direction in which the exhaust flows through exhaust passage 33 and the direction in which the exhaust flows through exhaust passage 36 become closer to being parallel. Because the exhaust is less likely to collide, extrusion loss can be suppressed.

[0032] The distance D1 from the turbine shaft 48 to the holes 42 and 46 may be 1.1 times or more, 1.2 times or more, 1.5 times or more, 1.8 times or more, 2 times or more, etc., the distance D2 from the shaft 48 to the holes 44.

[0033] The four cylinders of the internal combustion engine 10 are arranged in a row. Cylinder #1 is located at one end of the row. Cylinder #4 is located at the other end of the row. Cylinder #1 and cylinder #4 are farther apart than their adjacent cylinders. If the exhaust passage 20 and the exhaust passage 26 were to merge outside the turbine housing 30, as in the comparative example shown in Figure 3, the exhaust would collide and increase push-out loss. In the embodiment shown in Figure 1, the exhaust passage 20 and the exhaust passage 26 do not merge. The exhaust passage 32, which communicates with the exhaust passage 20, and the exhaust passage 36, which communicates with the exhaust passage 26, merge inside the turbine housing 30. By making the exhaust directions more parallel, push-out loss can be suppressed.

[0034] The internal combustion engine 10 is, for example, a four-cylinder engine. The exhaust passage 22 and the exhaust passage 24 are connected to the two central cylinders. The exhaust passage 22 and the exhaust passage 24 merge upstream of the point where they connect to the turbine housing 30. Because cylinders #2 and #3 are adjacent to each other, the angle between the exhaust passage 22 and the exhaust passage 24 is small. The exhaust gases are less likely to collide, and push-out loss is less likely to increase. The cylinders #1 and #4 at both ends are separated. The exhaust passage 20 and the exhaust passage 26 do not merge. The exhaust passage 32 and the exhaust passage 36 merge inside the turbine housing 30. At the merger point, the exhaust flows from cylinders #1 and #4 become nearly parallel. Push-out loss can be suppressed.

[0035] The angle A1 between the exhaust passage 33 and the exhaust passage 35 is, for example, 90 degrees or less, and may be 60 degrees or less, 45 degrees or less, 30 degrees or less, or 20 degrees or less. The closer the angle A1 is to 0 degrees, the closer the exhaust flow is to equilibrium, and the more effectively the extrusion loss can be suppressed.

[0036] The ignition order can be, for example, cylinders #1, #3, #4, #2. Cylinders #1 and #4 are not ignited consecutively. The exhaust gases emitted from cylinders #1 and #4 are less likely to collide. This reduces the push-out loss.

[0037] The number of cylinders may be four or less, or may be four or more. The cylinders form a row. The two exhaust passages 33 and 35 connected to the cylinders at both ends of the row are outer scrolls. Because the distance to the junction is long, the angle A1 can be made small. The turbocharger 100 has two scrolls. The two scrolls may be aligned in the direction of the turbine axis 48 or in the circumferential direction of the turbine. For example, the scrolls make half a revolution around the turbine. The longer scroll is connected to the cylinder at both ends.

[0038] The internal combustion engine 10 may be an in-line multi-cylinder engine or, for example, a V8 engine. Four of the eight cylinders form one bank. The other four cylinders form another bank. The embodiment can be applied to each of the two banks. Push-out loss can be suppressed in each bank. The crankshaft of a V8 engine may be a flat-plane or cross-plane. In the case of a flat-plane, the cylinders at both ends of the bank are not ignited consecutively. Push-out loss can be suppressed because exhaust gases are less likely to collide.

[0039] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention as described in the claims. [Explanation of symbols]

[0040] 10 internal combustion engine, #1, #2, #3, #4 cylinders, 20, 22, 24, 25, 26, 32, 33, 34, 35, 36, 37 exhaust passage, 30 turbine housing, 38 wastegate valve, 40 flange portion, 42, 44, 46 hole, 48 shaft, 100 turbocharger

Claims

1. A turbine housing; a first exhaust passage, a second exhaust passage, and two third exhaust passages connected to the turbine housing; The internal combustion engine has one first cylinder, one second cylinder, and two third cylinders, the first cylinder, the two third cylinders, and the second cylinder are arranged in this order; the first exhaust passage is connected to the first cylinder, and exhaust gas discharged from the first cylinder flows through the first exhaust passage; the second exhaust passage is connected to the second cylinder, and exhaust gas discharged from the second cylinder flows through the second exhaust passage; one of the third exhaust passages is connected to one of the third cylinders, and exhaust gas discharged from the one of the third cylinders flows through the third exhaust passage; the other third exhaust passage is connected to the other third cylinder, and exhaust gas discharged from the other third cylinder flows through the third exhaust passage; the turbine housing has a fourth exhaust passage, a fifth exhaust passage, and a sixth exhaust passage, and a flange portion; the one third exhaust passage and the other third exhaust passage join together upstream of the turbine housing to form a seventh exhaust passage, the first exhaust passage is connected to the fourth exhaust passage at a first connecting portion of the flange portion, the second exhaust passage is connected to the fifth exhaust passage at a second connection portion of the flange portion, the seventh exhaust passage is connected to the sixth exhaust passage at a third connecting portion of the flange portion, the fourth exhaust passage and the fifth exhaust passage join together, In the flange portion, the first connection portion and the second connection portion are aligned in a first direction, and the third connection portion is provided at a position spaced apart from the first connection portion and the second connection portion in a second direction intersecting the first direction, A turbocharger, wherein a distance from a turbine shaft to the first connection portion of the flange portion and a distance from the turbine shaft to the second connection portion are greater than a distance from the turbine shaft to the third connection portion.

2. 2. The turbocharger according to claim 1, wherein an angle between the fourth exhaust passage and the fifth exhaust passage at a position where the fourth exhaust passage and the fifth exhaust passage join together is 90 degrees or less.

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