Oil Separator

Abstract

To provide an oil separator capable of suppressing degradation of oil separation performance.SOLUTION: A case 10 has a first swelling portion 39 swelling to an inner side in an orthogonal direction. A first partition wall 21 and a second partition wall 68 extending downward from the first partition wall 21 are provided inside of the first swelling portion 39. A first opening 22 is provided between an end portion of the second partition wall 68 in the orthogonal direction and an inner wall of the first swelling portion 39 opposed to the end portion. A second opening 23 is provided between an end portion of the first partition wall 21 in a longitudinal direction and the inner wall of the first swelling portion 39 opposed to the end portion. The case 10 has: a first flow channel 24 positioned at a lower part of the first partition wall 21; a second flow channel 25 positioned at a side opposite to the first flow channel 24 via the first partition wall 21; and a communication passage 26 for communicating the first flow channel 24 and the second flow channel 25.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an oil separator. [Background technology]

[0002] Patent Document 1 discloses an oil separator provided on the side of a cylinder block of an internal combustion engine. The oil separator described in Patent Document 1 includes a case that forms a separation chamber for separating oil from blow-by gas, and a plurality of separator plates that partition the separation chamber. A first inlet / outlet and a second inlet / outlet that serve both as gas inlet and oil outlet are provided at the bottom of the case, spaced apart from each other in the width direction of the case. A gas outlet is provided at the top of the case.

[0003] In the oil separator described in Patent Document 1, blow-by gas is introduced into the interior of the case through a first inlet / outlet and a second inlet / outlet. The blow-by gas introduced into the interior of the case flows in a serpentine manner through a separation chamber partitioned by multiple separator plates, and is then discharged to the outside of the case through a gas outlet. The blow-by gas collides with the inner wall of the separation chamber, which includes multiple separator plates, causing oil to be separated from the blow-by gas. The oil separated from the blow-by gas is discharged to the outside of the case through the first inlet / outlet or the second inlet / outlet. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-78236 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to separate oil from blow-by gas, it is preferable to lengthen the path through which the blow-by gas flows inside the case so that the blow-by gas can come into contact with a wide area of ​​the inner wall of the separation chamber, including the separator plates. However, if many separator plates are installed, there will be areas inside the case where the blow-by gas has difficulty flowing. In this case, the oil separation performance of the oil separator may be reduced. [Means for solving the problem]

[0006] The oil separator for solving the above problem includes a case having an inlet through which blow-by gas flows in and an outlet provided above the inlet and through which the blow-by gas flows out, the oil separator separates oil contained in the blow-by gas inside the case and discharges the separated oil from the inlet to the outside of the case, and when a direction perpendicular to both the up-down direction and the left-right direction is defined as an orthogonal direction, the case has a bulging portion bulging out on one side of the orthogonal direction, and inside the bulging portion there is a first partition wall extending in the orthogonal direction and dividing the inside of the bulging portion into upper and lower parts, and a second partition wall extending downward from the first partition wall and dividing the inside of the bulging portion A second partition wall is provided to divide the interior into left and right sections, and a first opening is provided between an end of the second partition wall in the perpendicular direction and the inner wall of the bulge portion opposite the end, and a second opening is provided between the end of the first partition wall in the left-right direction and the inner wall of the bulge portion opposite the end, and the case has a first flow path located below the first partition wall, a second flow path located downstream of the first flow path in the flow direction of the blow-by gas and on the opposite side of the first flow path across the first partition wall, and a connecting passage located on the opposite side of the second partition wall from the first flow path and connecting the first flow path and the second flow path.

[0007] According to this configuration, blow-by gas that flows into the inside of the case from the inlet passes through the first flow path, the connecting passage, and the second flow path provided inside the bulge portion in that order, and is then discharged to the outside of the case from the outlet.

[0008] The blow-by gas that flows into the first flow passage flows toward one side in the orthogonal direction below the first partition wall. The blow-by gas then flows from the first flow passage into the communication passage through the first opening. The blow-by gas that flows into the communication passage passes through the second opening, moves above the first partition wall, and then flows into the second flow passage. The blow-by gas that flows into the second flow passage flows toward the other side opposite to the one side in the orthogonal direction above the first partition wall.

[0009] In this way, the blow-by gas flows in a meandering manner inside the bulging portion. This makes it easier for the blow-by gas to flow throughout the entire bulging portion. This increases the area over which the blow-by gas comes into contact with the inner wall of the bulging portion, including the first and second partition walls. This therefore prevents a decrease in the oil separation performance of the oil separator. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing an oil separator according to one embodiment. [Figure 2] FIG. 2 is a perspective view showing the inner case of one embodiment. [Figure 3] FIG. 3 is a front view showing the inner case of one embodiment. [Figure 4] FIG. 4 is a perspective view showing an outer case according to one embodiment. [Figure 5] FIG. 5 is a cross-sectional perspective view showing a part of the outer case of the case of one embodiment. [Figure 6] FIG. 6 is a cross-sectional view of the case taken along line 6-6 in FIG. [Figure 7] FIG. 7 is a cross-sectional view of the case taken along line 7-7 in FIG. [Figure 8] 8 is a cross-sectional view of the case taken along line 8-8 in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, one embodiment of the oil separator will be described with reference to FIGS. The oil separator of this embodiment is attached to the side of a cylinder block that constitutes the engine body of an internal combustion engine, and separates oil contained in blow-by gas into gas and liquid.

[0012] (Case 10) As shown in FIG. 1, the oil separator includes a case 10 that is attached to the side of a cylinder block (not shown).

[0013] The case 10 comprises an inner case 30 and an outer case 50. The inner case 30 is attached to the side of the cylinder block. The outer case 50 is located on the opposite side of the inner case 30 from the cylinder block. The inner case 30 and the outer case 50 face each other in an orthogonal direction (hereinafter simply referred to as the orthogonal direction) that is orthogonal to both the up-down direction and the left-right direction. Both the inner case 30 and the outer case 50 are formed from a resin material. The inner case 30 and the outer case 50 are divided in the orthogonal direction and joined to each other. The inner case 30 and the outer case 50 are examples of a "first case" and a "second case", respectively.

[0014] Hereinafter, the upper and lower sides in the vertical direction will be simply referred to as the upper and lower sides, respectively. Furthermore, in the perpendicular direction, the side closer to the cylinder block with respect to the case 10 will be referred to as the inside, and the side farther from the cylinder block will be referred to as the outside. For convenience, the right and left sides in the left-right direction when viewing the case 10 from the outside will be simply referred to as the right and left, respectively. Note that the left-right direction in this embodiment does not necessarily coincide with the vehicle width direction of the vehicle on which the oil separator is mounted. Furthermore, the upstream and downstream sides in the flow direction of blow-by gas will be simply referred to as the upstream and downstream sides.

[0015] As shown in FIGS. 2 and 3, the case 10 is provided therein with an upstream space S1 located on the upstream side and a downstream space S2 located downstream of and above the upstream space S1.

[0016] A portion of the upstream space S1 is located to the left of the downstream space S2. A portion of the downstream space S2 is located to the right of the upstream space S1. In other words, the downstream space S2 is biased to the right with respect to the upstream space S1.

[0017] (inner case 30) The inner case 30 has an inner facing wall 31 that faces the side surface of the cylinder block, and a peripheral wall 32 that protrudes outward along the entire periphery from the periphery of the inner facing wall 31. Although not shown, a joining portion that is joined to the outer case 50 is provided along the entire periphery of the surface of the peripheral wall 32 that faces the outer case 50.

[0018] The inner facing wall 31 has a first portion 31a that constitutes the upstream space S1 and a second portion 31b that constitutes the downstream space S2. The first portion 31a has a generally rectangular shape that is elongated in the left-right direction in a front view. The second portion 31b has a generally rectangular shape in a front view. A portion of the first portion 31a protrudes to the left more than the second portion 31b. A portion of the second portion 31b protrudes to the right more than the first portion 31a. The inner facing wall 31 as a whole has a crank shape in a front view.

[0019] The peripheral wall 32 has a first side wall 33 and a second side wall 34 that protrude outward from the first portion 31a and face each other in the left-right direction. The first side wall 33 protrudes from the left end of the first portion 31a. The second side wall 34 protrudes from the right end of the first portion 31a.

[0020] The peripheral wall 32 has a third side wall 35 and a fourth side wall 36 that protrude outward from the second portion 31b and face each other in the left-right direction. The third side wall 35 protrudes from the left end of the second portion 31b. The fourth side wall 36 protrudes from the right end of the second portion 31b.

[0021] The peripheral wall 32 has a first connecting wall 37 and a second connecting wall 38. The first connecting wall 37 extends in the left-right direction and connects the upper end of the first side wall 33 to the lower end of the third side wall 35. The second connecting wall 38 extends in the left-right direction and connects the upper end of the second side wall 34 to the lower end of the fourth side wall 36.

[0022] A first inlet 11 and a second inlet 12 through which blow-by gas flows are provided at a left-right distance apart in a lower portion of the first portion 31a. The first inlet 11 is located to the left of the second inlet 12. The first inlet 11 and the second inlet 12 communicate with the upstream space S1. The first inlet 11 and the second inlet 12 have a circular cross section.

[0023] An outlet 13 through which blow-by gas flows out is provided at an upper portion of the second portion 31b. The outlet 13 is provided at a position closer to the fourth side wall 36 than to the third side wall 35. The outlet 13 is provided in a portion of the second portion 31b that protrudes to the right of the first portion 31a. The outlet 13 communicates with the downstream space S2. The outlet 13 has a circular cross section.

[0024] As shown in Figures 1 and 2, the inner case 30 has a first bulge portion 39 and a second bulge portion 40 that bulge inward, which is one side in the perpendicular direction. The first bulge portion 39 is provided in the right part of the lower part of the downstream space S2. The second bulge portion 40 is provided in the left part of the upper part of the downstream space S2. The first bulge portion 39 bulges inward more than the second bulge portion 40. The first bulge portion 39 is an example of a "bulge portion."

[0025] 2 and 3, the internal space of the first bulging portion 39 has a generally rectangular parallelepiped shape that is long in the left-right direction and the perpendicular direction. The first bulging portion 39 has a first end wall 39a that closes the end on the inside.

[0026] In this embodiment, the first bulging portion 39 includes a range from the joint of the peripheral wall 32 to the first end wall 39a in the orthogonal direction. The internal space of the second bulging portion 40 is a generally rectangular parallelepiped that is elongated in the perpendicular direction. The second bulging portion 40 has a second end wall 40a that closes the inner end. The second end wall 40a is located outward from the first end wall 39a.

[0027] Inside the inner case 30, a first inner separation wall 41, a second inner separation wall 42, a third inner separation wall 43, a fourth inner separation wall 44, and a fifth inner separation wall 45 are provided to separate the oil contained in the blow-by gas.

[0028] (First inner separation wall 41) The first inner separation wall 41 protrudes outward from the first portion 31a of the inner opposing wall 31. The first inner separation wall 41 is provided above the second inlet 12. The first inner separation wall 41 extends at an incline so as to be positioned lower as it approaches the second side wall 34. Gaps through which blow-by gas passes are provided between both ends of the first inner separation wall 41 and the peripheral wall 32.

[0029] (Second inner separation wall 42) The second inner separation wall 42 protrudes outward from the second portion 31b of the inner opposing wall 31. The second inner separation wall 42 is provided above the first inner separation wall 41. The left end of the second inner separation wall 42 is connected to the third side wall 35. A gap is provided between the right end of the second inner separation wall 42 and the fourth side wall 36. The second inner separation wall 42 extends at an incline so as to be positioned lower as it approaches the fourth side wall 36. The second inner separation wall 42 covers the entire first inner separation wall 41 from above.

[0030] (Third inner separation wall 43) The third inner partition wall 43 protrudes outward from the first end wall 39a of the first bulging portion 39 and extends in the perpendicular direction. The third inner partition wall 43 extends to a portion of the first bulging portion 39 in the perpendicular direction. The third inner partition wall 43 divides the interior of the first bulging portion 39 into upper and lower sections. The third inner partition wall 43 is connected to the left inner wall of the first bulging portion 39. A gap through which blow-by gas passes is provided between the right end of the third inner partition wall 43 and the fourth side wall 36. The third inner partition wall 43 extends at an angle so that it is positioned lower as it approaches the fourth side wall 36.

[0031] (4th inner separation wall 44) The fourth inner partition wall 44 protrudes outward from the second portion 31b of the inner opposing wall 31. The fourth inner partition wall 44 is provided above the second inner partition wall 42 and the third inner partition wall 43. The right end of the fourth inner partition wall 44 is connected to the fourth side wall 36. A gap through which blow-by gas passes is provided between the left end of the fourth inner partition wall 44 and the third side wall 35. The fourth inner partition wall 44 extends at an incline so as to be positioned lower as it approaches the third side wall 35. The fourth inner partition wall 44 forms the top wall of the first bulging portion 39.

[0032] (5th inner separation wall 45) The fifth inner separation wall 45 protrudes outward from the second portion 31b of the inner opposing wall 31. A protruding end of the fifth inner separation wall 45 is located more inward than a protruding end of the peripheral wall 32. The fifth inner separation wall 45 is provided above the fourth inner separation wall 44. The fifth inner separation wall 45 curves along the opening edge of the outflow port 13. An upper end of the fifth inner separation wall 45 is connected to an upper portion of the peripheral wall 32. A gap through which blow-by gas passes is provided between the lower end of the fifth inner separation wall 45 and the fourth inner separation wall 44.

[0033] (1st protruding wall 46) A first protruding wall 46 that protrudes toward the outer case 50 is provided inside the inner case 30. The first protruding wall 46 protrudes outward from the second portion 31b of the inner opposing wall 31 and extends in the vertical direction. The first protruding wall 46 connects a portion of the second inner separation wall 42 slightly to the left of the right end thereof and the left end of the fourth inner separation wall 44.

[0034] (Fixed part 47) A plurality of fixing portions 47 that protrude toward the outer periphery of the inner case 30 and are fixed to the cylinder block are provided on the peripheral edge of the inner case 30. The fixing portions 47 are provided with insertion holes 47a into which bolts (not shown) are inserted to fix the inner case 30 to the cylinder block.

[0035] (Outer case 50) 4, the outer case 50 has an outer facing wall 51 facing the inner facing wall 31 of the inner case 30, and a peripheral wall 52 that protrudes inward along the entire periphery from the periphery of the outer facing wall 51. Although not shown, a joining portion that is joined to the inner case 30 is provided along the entire periphery of the surface of the peripheral wall 52 that faces the inner case 30.

[0036] The outer facing wall 51 has a first portion 51a that constitutes the upstream space S1 and a second portion 51b that constitutes the downstream space S2. The first portion 51a has a generally rectangular shape that is long in the left-right direction in a front view. The second portion 51b has a generally rectangular shape in a front view. A portion of the first portion 51a protrudes to the left more than the second portion 51b. A portion of the second portion 51b protrudes to the right more than the first portion 51a. The outer facing wall 51 as a whole has a crank shape in a front view.

[0037] The peripheral wall 52 has a first side wall 53 and a second side wall 54 that protrude inward from the first portion 51a and face each other in the left-right direction. The first side wall 53 protrudes from the left end of the first portion 51a. The second side wall 54 protrudes from the right end of the first portion 51a.

[0038] The peripheral wall 52 has a third side wall 55 and a fourth side wall 56 that protrude inward from the second portion 51b and face each other in the left-right direction. The third side wall 55 protrudes from the left end of the second portion 51b. The fourth side wall 56 protrudes from the right end of the second portion 51b.

[0039] The peripheral wall 52 has a first connecting wall 57 and a second connecting wall 58. The first connecting wall 57 extends in the left-right direction and connects the upper end of the first side wall 53 to the lower end of the third side wall 55. The second connecting wall 58 extends in the left-right direction and connects the upper end of the second side wall 54 to the lower end of the fourth side wall 56.

[0040] As shown in Figures 4 and 5, inside the outer case 50, a first outer separation wall 61, a second outer separation wall 62, a third outer separation wall 63, a fourth outer separation wall 64, and a fifth outer separation wall 65 are provided to separate the oil contained in the blow-by gas.

[0041] (First outer separation wall 61) The first outer separation wall 61 protrudes inward from the first portion 51a of the outer opposing wall 51. A protruding end surface of the first outer separation wall 61 faces a protruding end surface of the first inner separation wall 41 of the inner case 30. The first outer separation wall 61 extends at an incline so as to be positioned lower as it approaches the second side wall 54. Gaps are provided between both ends of the first outer separation wall 61 and the peripheral wall 52, respectively, through which blow-by gas passes.

[0042] (Second outer separation wall 62) The second outer separation wall 62 protrudes inward from the second portion 51b of the outer opposing wall 51. The second outer separation wall 62 is provided above the first outer separation wall 61. A protruding end surface of the second outer separation wall 62 faces a protruding end surface of the second inner separation wall 42 of the inner case 30. A left end of the second outer separation wall 62 is connected to the third side wall 55. The second outer separation wall 62 extends at an incline so as to be positioned lower as it approaches the fourth side wall 56. The second outer separation wall 62 covers the entire first outer separation wall 61 from above.

[0043] (Third outer separation wall 63) The third outer separation wall 63 protrudes inward from the second portion 51b of the outer opposing wall 51 and extends in the perpendicular direction. The third outer separation wall 63 protrudes inward further than the second outer separation wall 62 and the peripheral wall 52. The protruding end face of the third outer separation wall 63 faces the protruding end face of the third inner separation wall 43 of the inner case 30. The third outer separation wall 63 is connected to the right end of the second outer separation wall 62. The third outer separation wall 63 extends at an angle so as to be positioned lower as it approaches the fourth side wall 56.

[0044] 5 and 6, the protruding end of the third outer separation wall 63 is located inside the inner case 30, more specifically, inside the first bulging portion 39. A gap through which blow-by gas passes is provided between the right end of the third outer separation wall 63 and the fourth side wall 36 of the inner case 30. A gap through which blow-by gas passes is provided between the right end of the third outer separation wall 63 and the fourth side wall 56 of the outer case 50.

[0045] The third outer separation wall 63 constitutes a part of the first partition wall 21, which will be described later. The third outer separation wall 63 is connected to a second partition wall 68, which will be described later. (4th outer separation wall 64) As shown in Figures 4 and 5, the fourth outer separation wall 64 protrudes inward from the second portion 51b of the outer opposing wall 51. The fourth outer separation wall 64 is provided above the second outer separation wall 62 and the third outer separation wall 63. The protruding end surface of the fourth outer separation wall 64 faces the protruding end surface of the fourth inner separation wall 44 of the inner case 30. The right end of the fourth outer separation wall 64 is connected to the fourth side wall 56. A gap through which blow-by gas passes is provided between the left end of the fourth outer separation wall 64 and the third side wall 55. The fourth outer separation wall 64 extends at an angle so as to be positioned lower as it approaches the third side wall 55.

[0046] (5th outer separation wall 65) The fifth outer separation wall 65 protrudes inward from the second portion 51b of the outer opposing wall 51 and extends in the vertical direction. A protruding end surface of the fifth outer separation wall 65 faces the second end wall 40a of the second bulging portion 40.

[0047] The fifth outer separation wall 65 protrudes inward more than the peripheral wall 52. The protruding end of the fifth outer separation wall 65 is located inside the second bulging portion 40. A gap is provided between the upper and lower ends of the fifth outer separation wall 65 and the inner wall of the second bulging portion 40.

[0048] 8, the fifth outer separation wall 65 divides the interior of the second bulging portion 40 into left and right sections. The fifth outer separation wall 65 is provided at a position overlapping with the fifth inner separation wall 45 in the left-right direction.

[0049] (Second protruding wall 66) 4, a second protruding wall 66 that protrudes toward the inner case 30 is provided inside the outer case 50. The second protruding wall 66 protrudes inward from the second portion 51b of the outer facing wall 51 and extends in the vertical direction. The second protruding wall 66 connects the second outer separation wall 62 and the fourth outer separation wall 64. The tip of the second protruding wall 66 is located outward from the tip of the peripheral wall 52.

[0050] As shown in FIG. 7, the protruding end surface of the second protruding wall 66 faces the protruding end surface of the first protruding wall 46 of the inner case 30 in the orthogonal direction. (Throttling section 20) 6 and 7, a gap through which blow-by gas passes is provided between the protruding end surface of the first protruding wall 46 and the protruding end surface of the second protruding wall 66. The case 10 has a throttle portion 20 formed by the gap between the protruding end surface of the first protruding wall 46 and the protruding end surface of the second protruding wall 66. In the throttle portion 20, the cross-sectional area of ​​the flow path for blow-by gas is partially reduced. The throttle portion 20 has a slit shape extending in the vertical direction. The throttle portion 20 is provided downstream of a second flow path 25, which will be described later.

[0051] (Collision wall 67) 4 and 7, the outer case 50 is provided with a collision wall 67 facing the throttle portion 20 on the downstream side of the throttle portion 20. Blow-by gas that has passed through the throttle portion 20 collides with the collision wall 67. The collision wall 67 protrudes inward from the second portion 51b of the outer opposing wall 51 and extends in the vertical direction. The collision wall 67 connects the left ends of the second outer separation wall 62 and the fourth outer separation wall 64.

[0052] As shown in Fig. 7, the collision wall 67 is arranged alongside the second protruding wall 66 in the left-right direction. The collision wall 67 is arranged, for example, parallel to the second protruding wall 66. The collision wall 67 protrudes inward beyond the peripheral wall 52. A tip of the collision wall 67 is located inside the inner case 30. The collision wall 67 is arranged at a position overlapping with the first protruding wall 46 of the inner case 30 in the left-right direction.

[0053] (Internal structure of first bulging portion 39) As shown in Figures 5 and 6, the inside of the first bulge portion 39 is provided with a first partition wall 21 that divides the inside of the first bulge portion 39 into upper and lower sections, and a second partition wall 68 that divides the inside of the first bulge portion 39 into left and right sections.

[0054] The first partition wall 21 is composed of the third inner partition wall 43 and the third outer partition wall 63 described above. 4 and 5, the second partition wall 68 protrudes inward from the second portion 51b of the outer facing wall 51. The second partition wall 68 extends downward from the first partition wall 21. More specifically, the second partition wall 68 extends diagonally downward to the right from a portion slightly to the left of the right end of the third outer separation wall 63. A lower end of the second partition wall 68 is connected to the second connecting wall 58.

[0055] 6, the amount by which the second partition wall 68 protrudes from the second portion 51b is the same as the amount by which the third outer partition wall 63 protrudes from the second portion 51b. Therefore, the tip of the second partition wall 68 is located inside the first bulging portion 39.

[0056] A gap is provided between the lower end of the portion of the second partition wall 68 that is located inside the first bulging portion 39 and the second connecting wall 38 of the inner case 30. A first opening 22 is provided between the tip of the second partition wall 68 and a first end wall 39a, which is the inner wall of the first bulging portion 39 facing the tip in the perpendicular direction.

[0057] 5, a second opening 23 is provided between the right end of the first partition wall 21 and the fourth side wall 36, which is the inner wall of the first bulging portion 39 facing the right end in the left-right direction. The second opening 23 is formed by a gap between the third inner separation wall 43 and the fourth side wall 36 of the inner case 30, and a gap between the third outer separation wall 63 and the fourth side wall 36.

[0058] The case 10 has a first flow path 24, a second flow path 25, and a communication path 26, each formed inside the first bulging portion 39. The second flow path 25 is located above and downstream of the first flow path 24. The communication path 26 connects the first flow path 24 and the second flow path 25.

[0059] The first flow path 24 is located below the first partition wall 21 and to the left of the second partition wall 68. The first flow path 24 is defined by the first partition wall 21, the second partition wall 68, and the inner wall of the first bulging portion 39. The first flow path 24 extends in the perpendicular direction inside the first bulging portion 39.

[0060] The second flow path 25 is located on the opposite side of the first partition wall 21 from the first flow path 24, i.e., above the first partition wall 21. The second flow path 25 is defined by the first partition wall 21 and the inner wall of the first bulging portion 39. The second flow path 25 extends in the perpendicular direction inside the first bulging portion 39. The right end of the second flow path 25 opens toward the fourth side wall 36.

[0061] The communication passage 26 communicates with the first flow passage 24 via the first opening 22. The communication passage 26 communicates with the second flow passage 25 via an opening at the right end of the second flow passage 25. The communication passage 26 includes a second opening 23. The communication passage 26 is a space to the right of the first partition wall 21 within the internal space of the first bulging portion 39.

[0062] The operation of this embodiment will be described. As shown by arrows in FIG. 5, blow-by gas that flows into the case 10 from the inlets 11 and 12 collides with the lower surfaces of the first connecting walls 37 and 57, the first inner partition wall 41, and the first outer partition wall 61, respectively.

[0063] The blow-by gas then moves above the first inner partition wall 41 and the first outer partition wall 61 and collides with the lower surfaces of the second inner partition wall 42 and the second outer partition wall 62, respectively. As shown by the arrows in FIG. 6 , the blow-by gas then flows into the first bulging portion 39. The blow-by gas that has flowed into the first flow passage 24 of the first bulging portion 39 flows below the first partition wall 21 toward one side in the orthogonal direction, i.e., toward the inside. The blow-by gas then flows into the communicating passage 26 through the first opening 22. The blow-by gas that has flowed into the communicating passage 26 passes through the second opening 23 and moves above the first partition wall 21 inside the communicating passage 26. The blow-by gas then flows into the second flow passage 25 through the opening at the right end of the second flow passage 25. The blow-by gas that has flowed into the second flow passage 25 flows above the first partition wall 21 toward the opposite side in the orthogonal direction, i.e., toward the outside.

[0064] As shown by the arrows in Fig. 7, the blow-by gas that has passed through the second flow passage 25 passes through the throttle section 20. In the throttle section 20, the flow passage cross-sectional area of ​​the blow-by gas is partially reduced, so the flow velocity of the blow-by gas passing through the throttle section 20 increases. The blow-by gas with an increased flow velocity collides with the collision wall 67. Due to this collision, the oil contained in the blow-by gas adheres to the collision wall 67, and the oil is separated from the blow-by gas.

[0065] As shown by the arrows in Fig. 8, the blow-by gas then flows into the second bulging portion 40. Because the fifth outer partition wall 65 is located inside the second bulging portion 40, the blow-by gas flows inward along the fifth outer partition wall 65. After that, the blow-by gas moves to the right of the fifth outer partition wall 65, and then flows outward along the fifth outer partition wall 65. In this way, the blow-by gas flows inside the second bulging portion 40 in a serpentine manner.

[0066] Thereafter, the blow-by gas reaches the outlet 13 after going around the fifth inner separation wall 45. Then, the blow-by gas is discharged from the outlet 13 to the outside of the case 10. In this manner, the blow-by gas collides with the inner walls of the case 10, including the inner separation walls 41, 42, 43, 44, and 45 and the outer separation walls 61, 62, 63, 64, and 65. As a result, the oil contained in the blow-by gas is separated from the blow-by gas. The oil separated from the blow-by gas falls under its own weight and accumulates in the lower part of the case 10. As a result, the oil is discharged to the outside of the case 10 through the inlets 11 and 12.

[0067] The effects of this embodiment will be described. (1) The case 10 has a first bulging portion 39 that bulges inward in the orthogonal direction. A first partition wall 21 and a second partition wall 68 extending downward from the first partition wall 21 are provided inside the first bulging portion 39. A first opening 22 is provided between an end of the second partition wall 68 in the orthogonal direction and an inner wall of the first bulging portion 39 facing the end. A second opening 23 is provided between an end of the first partition wall 21 in the left-right direction and an inner wall of the first bulging portion 39 facing the end. The case 10 has a first flow path 24 located below the first partition wall 21, a second flow path 25 located on the opposite side of the first partition wall 21 from the first flow path 24, and a communication path 26 that connects the first flow path 24 and the second flow path 25.

[0068] With this configuration, blow-by gas that flows into the inside of the case 10 from each inlet 11, 12 passes through the first flow path 24, the connecting passage 26, and the second flow path 25, in that order, provided inside the first bulge portion 39, and is then discharged to the outside of the case 10 from the outlet 13.

[0069] The blow-by gas that has flowed into the first flow passage 24 flows inward below the first partition wall 21. Thereafter, the blow-by gas flows from the first flow passage 24 into the communication passage 26 through the first opening 22. The blow-by gas that has flowed into the communication passage 26 passes through the second opening 23, moves above the first partition wall 21 inside the communication passage 26, and then flows into the second flow passage 25. The blow-by gas that has flowed into the second flow passage 25 flows outward above the first partition wall 21.

[0070] In this way, the blow-by gas flows in a serpentine manner inside the first bulging portion 39. This makes it easier for the blow-by gas to flow throughout the entire first bulging portion 39. This increases the area over which the blow-by gas comes into contact with the inner walls of the first bulging portion 39, including the first partition wall 21 and the second partition wall 68. This prevents a decrease in the oil separation performance of the oil separator.

[0071] (2) On the downstream side of the second flow path 25, the throttle section 20 and the collision wall 67 facing the throttle section 20 on the downstream side of the throttle section 20 are provided. With this configuration, the blow-by gas, whose flow velocity has increased by passing through the throttle section 20, collides with the collision wall 67. This collision causes oil contained in the blow-by gas to adhere to the collision wall 67, so that the oil is separated from the blow-by gas. This improves the oil separation performance of the oil separator.

[0072] (3) The case 10 includes an inner case 30 as a first case and an outer case 50 as a second case, which are joined together. The inner case 30 has a first protruding wall 46. The outer case 50 has a second protruding wall 66 that faces the first protruding wall 46 in the perpendicular direction. The throttle section 20 is defined by a gap between the first protruding wall 46 and the second protruding wall 66.

[0073] According to this configuration, the inner case 30 and the outer case 50 are joined together to form the throttle portion 20 inside the case 10. Therefore, the throttle portion 20 can be easily realized.

[0074] Furthermore, for example, when the drawn portion 20 is formed on the inner wall of either the inner case 30 or the outer case 50, the mold for molding the inner case 30 or the outer case 50 may become complicated.

[0075] In this regard, according to the above configuration, the throttle portion 20 is formed by the gap between the first protruding wall 46 of the inner case 30 and the second protruding wall 66 of the outer case 50, so that the above-mentioned inconvenience can be avoided.

[0076] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. The throttle portion 20 may be formed by a gap in the left-right direction between the first protruding wall 46 and the second protruding wall 66. In this case, the first protruding wall 46 and the second protruding wall 66 may be provided at different positions in the left-right direction and may face each other in the left-right direction.

[0077] The throttle portion 20 may be a through-hole or a slit provided in the first protruding wall 46 or the second protruding wall 66. In this case, it is preferable that the first protruding wall 46 and the second protruding wall 66 are in contact with each other in the orthogonal direction or the left-right direction.

[0078] The shape of the throttle portion 20 is not limited to a slit shape, and may be, for example, a circular or polygonal cross section. The collision wall 67 may be provided on the inner case 30.

[0079] The restrictor 20 may be omitted from the case 10. The case 10 may have one inlet, or may have three or more inlets.

[0080] The case 10 may be configured by joining together a plurality of divided bodies that are divided into three or more parts. [Explanation of symbols]

[0081] 10…Case 11...1st inlet 12…Second inlet 13... Outlet 20...Diaphragm 21...First partition wall 22...First opening 23...Second opening 24...First flow path 25...Second flow path 26…Communication path 30...Inner case (first case) 39...First bulge (bulge) 46…First protruding wall 50...Outer case (second case) 66...Second protruding wall 67…Collision wall 68...Second partition wall

Claims

1. An oil separator comprising: a case having an inlet through which blow-by gas flows; and an outlet provided above the inlet and through which the blow-by gas flows; the oil separator separates oil contained in the blow-by gas inside the case and discharges the separated oil from the inlet to the outside of the case, When the direction perpendicular to both the up-down direction and the left-right direction is defined as the orthogonal direction, the case has a bulging portion that bulges out to one side in the orthogonal direction, a first partition wall extending in the perpendicular direction and dividing the interior of the bulging portion into upper and lower sections, and a second partition wall extending downward from the first partition wall and dividing the interior of the bulging portion into left and right sections, a first opening is provided between an end of the second partition wall in the orthogonal direction and an inner wall of the bulging portion facing the end, a second opening is provided between an end of the first partition wall in the left-right direction and an inner wall of the bulging portion facing the end, The case has a first flow passage located below the first partition wall, a second flow passage located downstream of the first flow passage in the flow direction of the blow-by gas and on the opposite side of the first flow passage with the first partition wall interposed therebetween, and a communication passage located on the opposite side of the second partition wall to the first flow passage and communicating the first flow passage with the second flow passage. Oil separator.

2. a throttle portion in which a flow path cross-sectional area of ​​the blow-by gas is partially reduced, and a collision wall in which the blow-by gas collides with the throttle portion on the downstream side of the throttle portion in the flow direction, the collision wall facing the throttle portion on the downstream side of the throttle portion in the flow direction. The oil separator according to claim 1 .

3. the case includes a first case and a second case that are divided in the orthogonal direction and joined to each other, the first case has a first protruding wall that protrudes toward the second case, the second case has a second protruding wall that protrudes toward the first case and faces the first protruding wall in the orthogonal direction, The throttle portion is formed by a gap between the first protruding wall and the second protruding wall. The oil separator according to claim 2 .

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