Oil separator for internal combustion engine

Abstract

To provide an oil separator for an internal combustion engine capable of improving oil separation performance.SOLUTION: An oil separator includes a case 10 having a first inflow port 11 and a second inflow port 12 into which blow-by gas flows, a gas outflow port 14 from which the blow-by gas flows, and an oil discharge port 13 from which oil separated from the blow-by gas is discharged. An inside of the case 10 is partitioned into an upstream side flow passage 15 and a downstream side flow passage 16 by a first separation wall 21. The first inflow port 11, the second inflow port 12, and the oil discharge port 13 communicate with the upstream side flow passage 15. The gas outflow port 14 communicates with the downstream side flow passage 16. A first communication passage 21a communicating between the upstream side flow passage 15 and the downstream side flow passage 16 above the oil discharge port 13 is provided in the first separation wall 21. The first separation wall 21 is positioned above the inflow ports 11, 12.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an oil separator for an internal combustion engine. [Background technology]

[0002] Conventionally, an oil separator provided on a side surface of a cylinder block of an internal combustion engine is known (see, for example, Patent Document 1). The oil separator described in Patent Document 1 includes a case forming a separation chamber for separating oil from blow-by gas, and a separator plate that divides the separation chamber. A first inlet and a second inlet, which serve both to introduce gas and to discharge oil, are provided at the bottom of the case, spaced apart from each other in the width direction of the case that intersects with the height direction. A gas discharge port is provided at the top of the case.

[0003] The separation chamber is divided into an upstream space below the separation chamber and a downstream space above the separation chamber by a separator plate. The separator plate is disposed above a space between the first and second entrances in the width direction.

[0004] The separator plate is formed with a first opening and a second opening that communicate between the upstream space and the downstream space. The first opening is located above the first port. The second opening is located above the second port.

[0005] The blow-by gas that flows into the case from the first or second port passes through the first and second openings and flows toward the gas exhaust port. At this time, the blow-by gas collides with the separator plate, so that oil is separated from the blow-by gas. Then, the oil is discharged to the outside of the case from the first or second port. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-78236 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in such an oil separator, when the flow rate of blow-by gas increases, the amount of oil contained in the blow-by gas also increases, so it is desired to improve the oil separation performance of the oil separator. [Means for solving the problem]

[0008] The oil separator for an internal combustion engine for solving the above problems comprises a case having a plurality of inlets through which blow-by gas flows and a gas outlet through which the blow-by gas flows, and separates oil contained in the blow-by gas at a separation wall provided inside the case and discharges the separated oil to the outside of the case through an oil outlet provided in the case, and when the upper side in the vertical direction is simply defined as the upper side, the inside of the case is divided into an upstream side flow passage located on the upstream side of the flow direction of the blow-by gas, The upstream flow path is partitioned by the separation wall into a downstream flow path located downstream and above the upstream flow path in the flow direction, and the upstream flow path is connected to the multiple inlets and the oil discharge outlet, and the downstream flow path is connected to the gas outlet, and each of the multiple inlets and the oil discharge outlet are aligned in a direction intersecting the vertical direction, and the separation wall is provided with a single communication passage above the oil discharge outlet that connects the upstream flow path and the downstream flow path, and the separation wall is located above the multiple inlets.

[0009] According to this configuration, the case is provided with a plurality of inlets, which makes it easier to increase the flow rate of blow-by gas flowing into the case, compared to an oil separator having a single inlet.

[0010] In addition, the blow-by gas that has flowed into the case collides with the lower surface of the separation wall located above the inlet. This causes the oil contained in the blow-by gas to be separated from the blow-by gas. The oil separated from the blow-by gas is collected in the lower part of the case and discharged to the outside of the case through the oil discharge port. Then, the blow-by gas flows from the upstream flow passage to the downstream flow passage through the communication passage and flows out of the case through the gas outlet.

[0011] Here, one communication passage is provided above the oil discharge port. This makes it easier for the blow-by gas that flows into the inside of the case through each inlet to collide with the separation wall before reaching the communication passage. In other words, the blow-by gas is easier to flow toward the downstream flow passage through the communication passage after colliding with the separation wall. This improves the oil separation performance. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a perspective view showing an oil separator according to an embodiment. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] FIG. 4 is a cross-sectional view showing a downstream flow path inside the case. [Figure 7] FIG. 11 is a front view showing an inner case in a modified oil separator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, one embodiment of an oil separator for an internal combustion engine will be described with reference to Figs. The oil separator of this embodiment is attached to a side surface 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.

[0014] (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).

[0015] Hereinafter, the flow direction of the blow-by gas will be referred to simply as the flow direction. The direction in which the case 10 faces the side of the cylinder block will be referred to as the facing direction. The direction perpendicular to both the vertical direction and the facing direction will be referred to as the width direction. Additionally, the upper and lower sides in the vertical direction will be referred to simply as the upper and lower sides, respectively. In the facing direction, the side close to the cylinder block will be referred to as the inside, and the side away from the cylinder block will be referred to as the outside.

[0016] The case 10 comprises an inner case 30 attached to a side surface of the cylinder block, and an outer case 50 disposed on the opposite side of the cylinder block across the inner case 30. The inner case 30 and the outer case 50 are joined to each other. The inner case 30 and the outer case 50 are both formed from a resin material, for example. The inner case 30 and the outer case 50 correspond to the "first member" and the "second member", respectively.

[0017] Next, the internal structure of the case 10 will be described with reference to FIGS. 2 and 3 which show the internal structure of the inner case 30 for convenience. 2 and 3, the case 10 has a first inlet 11 and a second inlet 12 through which blow-by gas flows in, an oil outlet 13 through which oil is discharged, and a gas outlet 14 through which the blow-by gas flows out. The first inlet 11, the second inlet 12, and the oil outlet 13 are provided in the lower part of the case 10. The gas outlet 14 is provided in the upper part of the case 10.

[0018] 3, the first inlet 11, the second inlet 12, and the oil outlet 13 are arranged in this order in a direction intersecting the vertical direction. In other words, the oil outlet 13 is located on one side of the first inlet 11 and the second inlet 12 in the arrangement direction of the first inlet 11 and the second inlet 12.

[0019] A first separation wall 21 and a second separation wall 22 for separating oil contained in blow-by gas are provided inside the case 10. The first separation wall 21 is provided above the inlets 11, 12. The second separation wall 22 is provided above the oil discharge port 13. The second separation wall 22 is located above the first separation wall 21.

[0020] The inside of the case 10 is partitioned into an upstream flow passage 15 and a downstream flow passage 16 by a first separation wall 21. The upstream flow passage 15 is located upstream in the flow direction inside the case 10. The downstream flow passage 16 is located downstream in the flow direction and above the upstream flow passage 15. The upstream flow passage 15 is connected to each of the inlets 11 and 12 and an oil discharge port 13.

[0021] The first separation wall 21 is provided with one first communication passage 21a that communicates between the upstream flow passage 15 and the downstream flow passage 16. The first communication passage 21a is provided above the oil discharge port 13. The second separation wall 22 is located above the first communication passage 21a.

[0022] The downstream flow passage 16 is divided into a first downstream flow passage 16a and a second downstream flow passage 16b by a second separation wall 22. The first downstream flow passage 16a is located on the upstream side in the flow direction inside the downstream flow passage 16. The second downstream flow passage 16b is located downstream and above the first downstream flow passage 16a in the flow direction. The second downstream flow passage 16b is in communication with the gas outlet 14.

[0023] The second separation wall 22 is provided with one second communication passage 22a that communicates with the first downstream flow passage 16a and the second downstream flow passage 16b. The second communication passage 22a is provided above the first separation wall 21. The first communication passage 21a and the second communication passage 22a are provided at positions that do not overlap with each other in the vertical direction. As a result, the first communication passage 21a and the second communication passage 22a are located on opposite sides of the downstream flow passage 16 in the width direction.

[0024] (Inner case 30) 2 and 3, 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 over the entire circumference 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 over the entire circumference on the surface of the peripheral wall 32 that faces the outer case 50.

[0025] The inner facing wall 31 has a first portion 31a having a generally rectangular shape that is long in the vertical direction, and a second portion 31b extending from a lower portion of the first portion 31a to one side in the width direction. The inner facing wall 31 has a generally L-shape as a whole.

[0026] The peripheral wall 32 has a first side wall 33 and a second side wall 34 opposed to each other in the width direction. The first side wall 33 and the second side wall 34 constitute both the upstream flow passage 15 and the downstream flow passage 16.

[0027] The first side wall 33 has an upper first side wall 33a protruding outward from one end in the width direction of the first portion 31a, and a lower first side wall 33b protruding outward from one end in the width direction of the second portion 31b.

[0028] The second side wall 34 protrudes outward from an end opposite to the one end in the width direction of the first portion 31a. The second side wall 34 faces both the upper first side wall 33a and the lower first side wall 33b.

[0029] The peripheral wall 32 has a connecting wall 35 that connects the upper first side wall 33a and the lower first side wall 33b. The connecting wall 35 extends in the width direction and faces a portion of the peripheral wall 32 that forms the bottom surface of the inner case 30.

[0030] 3, the above-mentioned first inlet 11, second inlet 12, and oil discharge port 13 are provided at intervals from each other in the lower part of the inner opposing wall 31. The first inlet 11, second inlet 12, and oil discharge port 13 are provided in this order from the first side wall 33 toward the second side wall 34. The second inlet 12 is located lower than the first inlet 11. The oil discharge port 13 is located lower than the second inlet 12.

[0031] The gas flow outlet 14 described above is provided at an upper portion of the inner opposing wall 31. The gas flow outlet 14 is located above the oil discharge outlet 13. The gas flow outlet 14 is located on the opposite side to the oil discharge outlet 13 in the vertical direction, with a second partition plate 42 described later interposed therebetween.

[0032] (First partition plate 41) A first partition plate 41 is provided between the first side wall 33 and the second side wall 34 and above the second inlet 12. The first partition plate 41 protrudes outward from the first portion 31a of the inner facing wall 31. The first partition plate 41 extends so as to be positioned upward as it goes from the first side wall 33 toward the second side wall 34. The first partition plate 41 corresponds to the "partition plate" of the "first member".

[0033] The inside of the inner case 30 is divided into an upstream flow path 15 and a first downstream flow path 16a by a first partition plate 41. In the inner case 30, the connecting wall 35 and the first partition plate 41 form a part of the first separation wall 21 described above.

[0034] A gap is provided between the end 41a of the first partition plate 41 facing the second side wall 34 and the second side wall 34. The above-mentioned first communication passage 21a is formed by this gap. Note that a small gap is provided between the end of the first partition plate 41 opposite to the end 41a and the peripheral wall 32.

[0035] The end 41a is located between the second inlet 12 and the oil discharge port 13 in the width direction. In other words, the opening edge of the first communication passage 21a formed by the end 41a is located above the portion between the second inlet 12 and the oil discharge port 13.

[0036] (Second partition plate 42) A second partition plate 42 is provided above the first partition plate 41 and above the oil drain port 13. The second partition plate 42 protrudes from the second side wall 34 toward the first side wall 33. The second partition plate 42 extends from the second side wall 34 so as to be positioned lower toward the first side wall 33. The second partition plate 42 is connected to the inner facing wall 31 over its entirety.

[0037] The inside of the inner case 30 is divided into a first downstream flow passage 16a and a second downstream flow passage 16b by a second partition plate 42. In the inner case 30, the second partition plate 42 forms a part of the second separation wall 22 described above.

[0038] A gap is provided between an end 42a of the second partition plate 42 facing the upper first side wall 33a and the upper first side wall 33a. This gap constitutes a part of the second communication passage 22a described above.

[0039] The end 42a is located between the second inlet 12 and the oil discharge port 13 in the width direction. In other words, the opening edge of the second communication passage 22a formed by the end 42a is located above the portion between the second inlet 12 and the oil discharge port 13.

[0040] Although not shown in the drawings, a joining portion that is joined to the outer case 50 is provided on the surface of the second partition plate 42 that faces the outer case 50. As described above, the inner case 30 is joined to the outer case 50 at the peripheral wall 32 and the second partition plate 42.

[0041] (1st shielding plate 43) The second downstream flow passage 16b is provided with a first shielding plate 43 protruding outward from the first portion 31a of the inner facing wall 31. The first shielding plate 43 extends in the vertical direction. The first shielding plate 43 is connected to a portion of the peripheral wall 32 facing the second partition plate 42. The amount of protrusion of the first shielding plate 43 from the inner facing wall 31 is greater than the amount of protrusion of the peripheral wall 32 from the inner facing wall 31. Therefore, the tip of the first shielding plate 43 is located inside the outer case 50. Note that a gap is provided between the tip of the first shielding plate 43 in the facing direction and the inner surface of the outer case 50.

[0042] (Fixed part 36) A plurality of fixing portions 36 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. Each fixing portion 36 is provided with an insertion hole 36a into which a bolt (not shown) is inserted to fix the inner case 30 to the cylinder block.

[0043] (Outer case 50) As shown in FIG. 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 protruding inwardly from the periphery of the outer facing wall 51 around the entire periphery.

[0044] The outer facing wall 51 has a first portion 51a having a substantially rectangular shape and a second portion 51b extending from a lower portion of the first portion 51a to one side in the width direction. The outer facing wall 51 has a substantially L-shape as a whole.

[0045] The peripheral wall 52 has a first side wall 53 and a second side wall 54 that face each other in the width direction. The first side wall 53 and the second side wall 54 form both the upstream flow path 15 and the downstream flow path 16.

[0046] A part of the configuration of the outer case 50 has a shape corresponding to the configuration of the inner case 30. For this reason, hereinafter, parts of the configuration of the outer case 50 that correspond to the configuration of the inner case 30 will be denoted by the symbols "5*" and "6*," which are obtained by adding "20" to the symbols "3*" and "4*," which indicate the configuration of the inner case 30, and duplicated explanations may be omitted.

[0047] (First partition plate 61) A first partition plate 61 is provided between the first side wall 53 and the second side wall 54 to divide the inside of the outer case 50 into an upstream flow path 15 and a first downstream flow path 16a. The first partition plate 61 faces the first partition plate 41 of the inner case 30 in the facing direction. The first partition plate 61 connects the first side wall 53 and the second side wall 54. The first partition plate 61 corresponds to the "partition plate" of the "second member".

[0048] In the outer case 50, a part of the first separation wall 21 described above is formed by the connecting wall 55 and the first partition plate 61. As described above, in this embodiment, the first separation wall 21 is formed by the connecting wall 35 and the first partition plate 41 of the inner case 30, and the connecting wall 55 and the first partition plate 61 of the outer case 50. In addition, as shown in Fig. 5, a first communication passage 21a is formed by the gap between the first partition plate 41 and the second side wall 34 of the inner case 30, and the first partition plate 61 of the outer case 50.

[0049] (Second partition plate 62) 4, a second partition plate 62 that divides the inside of the outer case 50 into a first downstream flow path 16a and a second downstream flow path 16b is provided above the first partition plate 61. The second partition plate 62 is joined over its entirety to the second partition plate 42 of the inner case 30 in the opposing direction.

[0050] In the outer case 50, a part of the above-mentioned second separation wall 22 is configured by the second partition plate 62. As described above, in this embodiment, the second separation wall 22 is configured by the second partition plate 42 of the inner case 30 and the second partition plate 62 of the outer case 50.

[0051] A gap is provided between the end 62a of the second partition plate 62 facing the upper first side wall 53a and the upper first side wall 53a. This gap constitutes a part of the second communication passage 22a described above. As described above, the second communication passage 22a is constituted by the gap between the end 42a of the inner case 30 and the upper first side wall 33a, and the gap between the end 62a of the outer case 50 and the upper first side wall 53a.

[0052] (Second shielding plate 63 and third shielding plate 64) The second downstream flow passage 16b is provided with a second shielding plate 63 and a third shielding plate 64 protruding inward from the first portion 51a of the outer opposing wall 51. The second shielding plate 63 and the third shielding plate 64 are provided at an interval from each other in the width direction. The third shielding plate 64 is provided downstream of the second shielding plate 63 in the flow direction.

[0053] The second shielding plate 63 and the third shielding plate 64 extend in the vertical direction. The second shielding plate 63 and the third shielding plate 64 are connected to a portion of the peripheral wall 52 that faces the second partition plate 62. 6, the amount of protrusion of each of the second shielding plate 63 and the third shielding plate 64 from the outer facing wall 51 is greater than the amount of protrusion of the peripheral wall 52 from the outer facing wall 51. The amount of protrusion of the second shielding plate 63 is greater than the amount of protrusion of the third shielding plate 64. Therefore, each of the protruding ends of the second shielding plate 63 and the third shielding plate 64 is located inside the inner case 30. Note that a gap is provided between each of the protruding ends of the second shielding plate 63 and the third shielding plate 64 in the opposing direction and the inner surface of the inner case 30.

[0054] The first shielding plate 43 of the inner case 30 described above is located between the second shielding plate 63 and the third shielding plate 64. As a result, in the second downstream flow passage 16b, the shielding plates 63, 43, 64 form a flow passage through which the blow-by gas flows in a meandering manner.

[0055] The operation of this embodiment will be described. As shown in Fig. 5, the blow-by gas flowing into the case 10 from each of the inlets 11, 12 collides with the lower surface of the first separation wall 21 located above each of the inlets 11, 12. 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, and is discharged to the outside of the case 10 through the oil discharge port 13. Then, the blow-by gas flows from the upstream passage 15 toward the first downstream passage 16a through the first communication passage 21a.

[0056] Here, one first communication passage 21a is provided above the oil discharge port 13. This makes it easier for the blow-by gas that has flowed into the case 10 through each of the inlets 11, 12 to collide with the first separation wall 21 before reaching the first communication passage 21a. That is, after colliding with the first separation wall 21, the blow-by gas is easier to flow through the first communication passage 21a toward the first downstream flow passage 16a (above, action 1).

[0057] The blow-by gas that has flowed into the first downstream flow passage 16a through the first communication passage 21a collides with the lower surface of the second separation wall 22 located above the first communication passage 21a. As a result, the oil that has not been separated from the blow-by gas by the first separation wall 21 is separated from the blow-by gas (the above is action 2).

[0058] Thereafter, the blow-by gas flows from the first downstream passage 16a to the second downstream passage 16b through the second communication passage 22a. As shown in FIG. 6, the blow-by gas that has flowed into the second downstream flow passage 16b through the second communication passage 22a flows in a serpentine manner between the shielding plates 63, 43, and 64, and flows out of the case 10 from the gas outlet .

[0059] The effects of this embodiment will be described. (1) The oil separator includes a case 10 having a first inlet 11 and a second inlet 12 through which blow-by gas flows, a gas outlet 14 through which the blow-by gas flows, and an oil outlet 13 through which oil separated from the blow-by gas is discharged. The inside of the case 10 is partitioned into an upstream flow passage 15 and a downstream flow passage 16 by a first separation wall 21. The upstream flow passage 15 is connected to the first inlet 11, the second inlet 12, and the oil outlet 13. The downstream flow passage 16 is connected to the gas outlet 14. The first separation wall 21 is provided with one first communication passage 21a above the oil outlet 13, which communicates between the upstream flow passage 15 and the downstream flow passage 16. The first separation wall 21 is located above each of the inlets 11 and 12.

[0060] According to this configuration, the case 10 is provided with the first inlet 11 and the second inlet 12. Therefore, compared to an oil separator having a single inlet, it is easier to increase the flow rate of blow-by gas flowing into the inside of the case 10.

[0061] Furthermore, according to the above configuration, since the above-mentioned effect 1 is achieved, the oil separation performance of the oil separator can be improved. (2) The oil discharge port 13 is located lower than each of the oil inlets 11 and 12.

[0062] According to this configuration, the oil separated from the blow-by gas by the first separation wall 21 and accumulated in the lower part of the case 10 can easily flow toward the oil discharge port 13. Therefore, the oil discharge performance can be improved.

[0063] Moreover, with the above-described configuration, backflow of oil from the oil outlet 13 to each of the inlets 11, 12 can be suppressed. (3) The oil discharge port 13 is located on one side of the first inlet 11 and the second inlet 12 in the arrangement direction of the first inlet 11 and the second inlet 12.

[0064] According to this configuration, the inlets farther from the oil discharge port 13 are provided at positions farther from the first communication passage 21a. Therefore, the blow-by gas that flows into the inside of the case 10 through the inlets is more likely to collide with the first separation wall 21 before reaching the first communication passage 21a. This makes it possible to further improve the oil separation performance.

[0065] (4) The case 10 includes an inner case 30 and an outer case 50 joined together. The inner case 30 has a first side wall 33 and a second side wall 34. The outer case 50 has a first side wall 53 and a second side wall 54. The first side walls 33, 53 and the second side walls 34, 54 form both the upstream flow path 15 and the downstream flow path 16. The inner case 30 and the outer case 50 each have a first partition plate 41, 61 that forms the first separation wall 21. A gap that forms the first communication passage 21a is provided between the first partition plate 41 of the inner case 30 and the second side wall 34.

[0066] According to this configuration, a gap that constitutes the first communication passage 21a is provided between the first partition plate 41 of the inner case 30 and the second side wall 34. Therefore, by adjusting the length of the first partition plate 41, the size of the gap, that is, the opening area of ​​the first communication passage 21a, can be adjusted. For example, the longer the length of the first partition plate 41, the smaller the gap, making it easier to separate the oil. Also, the longer the length of the first partition plate 41, the smaller the opening area of ​​the first communication passage 21a, increasing the pressure loss of the blow-by gas. For this reason, by a simple method such as appropriately setting the length of the first partition plate 41, it is possible to achieve both improvement in oil separation performance and suppression of pressure loss of the blow-by gas.

[0067] (5) A second separation wall 22 is provided inside the case 10, and is located above the first communication passage 21a in the downstream flow passage 16. The second separation wall 22 separates the oil contained in the blow-by gas that flows into the downstream flow passage 16 through the first communication passage 21a.

[0068] According to this configuration, the above-mentioned effect 2 is achieved, and the oil separation performance of the oil separator can be further improved. <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0069] The end 42a of the second partition plate 42 in the inner case 30 may be connected to the upper first side wall 33a. The end 62a of the second partition plate 62 in the outer case 50 may be connected to the upper first side wall 53a.

[0070] The second separation wall 22 can be omitted from the case 10. A gap may be provided between the first partition plate 61 and the second side wall 54 of the outer case 50 .

[0071] 7, the first inlet 11 and the second inlet 12 may be aligned linearly in the width direction, and the oil discharge port 13 may be located below the inlets 11, 12. Even in this case, the above-mentioned effect (2) can be achieved.

[0072] The oil discharge port 13 may be provided between the first inlet 11 and the second inlet 12. In this case, a first separation wall 21 may be provided above each of the first inlet 11 and the second inlet 12.

[0073] The first inlet 11, the second inlet 12, and the oil discharge port 13 may be aligned linearly in the width direction. The case 10 may be provided with three or more inlets. [Explanation of symbols]

[0074] 10…Case 11...1st inlet 12…Second inlet 13…Oil outlet 14…Gas outlet 15…Upstream side flow path 16…Downstream side flow path 16a…First downstream side flow path 16b…Second downstream side flow path 21…First separation wall 21a…First communication path 22…Second separation wall 22a…Second communication path 30…Inner case 31…Inner opposing wall 31a,51a…First part 31b,51b…Second part 32,52…Peripheral wall 33,53…First side wall 33a,53a…Upper first side wall 33b,53b…Lower first side wall 34,54…Second side wall 35,55…Connecting wall 36…Fixing part 36a…Insertion hole 41,61…First partition plate 41a…End part 42,62…Second partition plate 42a,62a…End part 43…First shielding plate 50…Outer case 51…Outer opposing wall 63…Second shielding plate 64…Third shielding plate

Claims

1. An oil separator comprising a case having a plurality of inlets through which blow-by gas flows and a gas outlet through which the blow-by gas flows, the oil separator separating oil contained in the blow-by gas at a separation wall provided inside the case, and discharging the separated oil to the outside of the case through an oil outlet provided in the case, When the vertical direction is simply defined as "upward," The interior of the case is partitioned by the separation wall into an upstream-side flow passage located upstream in a flow direction of the blow-by gas, and a downstream-side flow passage located downstream and above the upstream-side flow passage in the flow direction, The upstream flow passage is in communication with the plurality of inlets and the oil discharge port, the downstream flow passage is in communication with the gas outlet, Each of the plurality of oil inlets and the oil discharge port are aligned in a direction intersecting a vertical direction, The separation wall is provided with a communication passage that communicates the upstream flow passage and the downstream flow passage above the oil discharge port, The separation wall is located above the plurality of inlets, The case includes a first member and a second member joined to each other, The first member and the second member each have a first side wall and a second side wall opposite to the first side wall, the first side wall and the second side wall constitute both the upstream flow path and the downstream flow path, the first member and the second member each have a partition plate provided between the first side wall and the second side wall and constituting the separation wall, a gap is provided between the partition plate of either the first member or the second member and the second side wall, the gap being partitioned by the either partition plate and the second side wall and constituting the communication passage; The partition plate of the other of the first member and the second member and the second side wall are connected to each other. Oil separator for internal combustion engines.

2. The oil discharge port is located vertically below the plurality of oil inlets.

2. An oil separator for an internal combustion engine according to claim 1.

3. The oil discharge port is located on one side of the plurality of inlets in an arrangement direction of the plurality of inlets.

3. An oil separator for an internal combustion engine according to claim 1 or 2.

4. When the separation wall is a first separation wall, A second separation wall is provided inside the case, the second separation wall being located above the communication passage in the downstream flow passage and separating oil contained in the blow-by gas that has flowed into the downstream flow passage through the communication passage. The oil separator for an internal combustion engine according to any one of claims 1 to 3.

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