JP6311463B2 - Oil separator - Google Patents

Description

  The present invention relates to an oil separator that separates oil contained in blow-by gas of an internal combustion engine.

  The internal combustion engine is provided with a return passage for returning the blow-by gas in the crank chamber to the intake passage. The cylinder head cover is integrally provided with a housing of an oil separator that forms part of the reflux passage and separates mist-like oil contained in blow-by gas (for example, see Patent Document 1). A gas inlet is opened in the bottom wall of the housing. The bottom wall is formed with an oil outlet for discharging liquid oil in the housing to the outside. Moreover, the outflow port from which blow-by gas flows out is formed in the top wall of the housing.

JP 2010-248935 A

  Incidentally, an intake camshaft and an exhaust camshaft of the internal combustion engine are located immediately below the bottom wall of the housing. Therefore, the oil adhering to these camshafts scatters with the rotation of these camshafts and adheres to the lower surface of the bottom wall. When the internal combustion engine is mounted to be inclined with respect to the vehicle, the bottom wall is inclined, so that the liquid oil moves along the bottom surface of the bottom wall due to its own weight, and passes through the gas inlet into the housing. There is a risk of inflow.

  An object of the present invention is to provide an oil separator capable of suppressing liquid oil from flowing into a housing.

  An oil separator for achieving the above object is for separating mist-like oil contained in blow-by gas of an internal combustion engine, comprising a bottom wall in which a gas inflow port is formed, and the lower surface of the bottom wall A concave groove is formed around the gas inlet.

  According to the configuration, since the concave groove is formed around the gas inlet on the lower surface of the bottom wall, the liquid oil that has moved along the lower surface of the bottom wall flows into the gas inlet over the concave groove. There is little to do, and the oil will fall by its own weight from the edge of the groove.

  An oil separator for achieving the above object is for separating mist-like oil contained in blow-by gas of an internal combustion engine, comprising a bottom wall formed with a gas inlet, and a lower surface of the bottom wall. A stepped portion is formed around the gas inlet in the direction toward the upper side.

  According to this configuration, since the stepped portion is formed around the gas inlet on the bottom surface of the bottom wall, the liquid oil that has traveled along the bottom surface of the bottom wall passes through the stepped portion to the gas. The oil hardly flows into the inflow port, and the oil falls by its own weight from the edge of the stepped portion.

  According to the present invention, it is possible to prevent liquid oil from flowing into the housing.

The perspective view of the oil separator in one embodiment. FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2. The expanded sectional view which expands and shows the gas inflow port of the oil separator of the embodiment. The expanded sectional view which expands and shows the gas inflow port of the oil separator of a modification. The expanded sectional view which expands and shows the gas inflow port of the oil separator of another modification. The expanded sectional view which expands and shows the gas inflow port of the oil separator of another modification. The expanded sectional view which expands and shows the gas inflow port of the oil separator of another modification.

Hereinafter, an embodiment will be described with reference to FIGS.
As shown in FIGS. 1 to 3, the housing 13 of the oil separator 11 is formed integrally with the cylinder head cover 12 of the internal combustion engine and has a box-shaped housing body 131 that opens downward, and the housing body 131. And a bottom wall 14 having a rectangular shape in a top view covering the lower opening. The bottom wall 14 is fixed to the periphery of the lower opening of the housing body 131 by vibration welding or the like.

  A gas inlet 15 having a square cross section is formed on one end side (left end side) in the longitudinal direction of the bottom wall 14 and communicates with a crank chamber of the internal combustion engine via a flow path (not shown). A convex portion 141 that forms the inner peripheral surface of the gas inlet 15 is formed on the upper surface of the bottom wall 14. As shown in FIG. 3, a concave groove 142 is formed around the gas inlet 15 on the lower surface of the convex portion 141, that is, the lower surface of the bottom wall 14. Further, the upstream end 15 a of the gas inlet 15 is located on a virtual plane 24 including the lower surface of the bottom wall 14.

  A gas outlet 16 communicating with the intake passage of the internal combustion engine is provided on the side wall of the housing 13 through a flow path (not shown). The gas outlet 16 is located in the vicinity of the end opposite to the position where the gas inlet 15 is formed in the longitudinal direction. A gas flow path 17 that is a flow path for blow-by gas is formed between the gas inlet 15 and the gas outlet 16 in the housing 13.

  A first separation plate 18 projects from the upper surface of the bottom wall 14. As shown in FIG. 3, a gap 19 for securing the gas flow path 17 is formed between the upper end of the first separation plate 18 and the lower surface of the top wall 132 of the housing body 131.

  A second separation plate 21 protrudes from the lower surface of the top wall 132 downstream of the gap 19. A gap 22 for securing the gas flow path 17 is formed between the lower end of the second separation plate 21 and the upper surface of the bottom wall 14.

An oil discharge port 20 is formed between the first separation plate 18 and the second separation plate 21 in the bottom wall 14.
As shown in FIG. 1, an oil passage 23 is formed at the lower end corner of the first separation plate 18. Then, the oil separated by the first separation plate 18 is guided to the oil discharge port 20 through the oil passage 23.

Next, the operation of the oil separator 11 of this embodiment will be described.
Blow-by gas generated in the crank chamber with the operation of the internal combustion engine flows into the housing 13 from the gas inlet 15 of the oil separator 11 and flows through the gas flow path 17 toward the gas outlet 16.

  At this time, the blow-by gas collides with the surface of the first separation plate 18 on the gas inlet 15 side, so that the mist-like oil contained in the blow-by gas adheres to the same surface and is separated from the gas. Subsequently, the blow-by gas that has passed through the gap 19 on the first separation plate 18 collides with the surface of the second separation plate 21 that faces the first separation plate 18, so that the oil remaining in the blow-by gas is on the same surface. It adheres and is separated from the gas.

  The oil separated by the first separation plate 18 flows downward, is guided to the oil discharge port 20 through the oil passage 23 and is discharged from the oil discharge port 20. The oil separated by the second separation plate 21 flows downward and is discharged from the oil discharge port 20. Thus, the oil discharged to the outside of the housing 13 is used to lubricate movable parts such as an intake cam shaft and an exhaust cam shaft (not shown) located inside the cylinder head cover 12.

  By the way, since the intake cam shaft and the exhaust cam shaft are present directly below the bottom wall 14 of the housing 13, the liquid oil adhering to the cam shafts scatters as the cam shafts rotate, and the bottom wall It adheres to the lower surface of 14. When the internal combustion engine is mounted inclined with respect to the vehicle, the bottom wall 14 is inclined, so that liquid oil moves along the lower surface of the bottom wall 14 by its own weight. Here, according to the oil separator 11 of the present embodiment, the concave groove 142 is formed around the gas inlet 15 on the lower surface of the bottom wall 14 over the entire circumference. For this reason, the liquid oil that has moved along the lower surface of the bottom wall 14 hardly flows into the gas inlet 15 beyond the groove 142, and the oil falls from the edge of the groove 142 by its own weight. It becomes. Accordingly, the liquid oil is prevented from flowing into the housing 13.

According to the oil separator according to the present embodiment described above, the following effects can be obtained.
(1) The oil separator 11 separates mist-like oil contained in blow-by gas of an internal combustion engine, and includes a bottom wall 14 in which a gas inlet 15 is formed, and a gas inlet on the lower surface of the bottom wall 14 A concave groove 142 is formed around 15.

  According to such a configuration, liquid oil that has traveled along the lower surface of the bottom wall 14 hardly flows into the gas inlet 15 beyond the concave groove 142. Therefore, the liquid oil can be prevented from flowing into the housing 13.

  (2) The concave groove 142 is formed over the entire circumference of the gas inlet 15. For this reason, it is possible to suppress the liquid oil that has traveled along the lower surface of the bottom wall 14 from flowing into the gas inlet 15 over the entire circumference of the concave groove 142. Therefore, it is possible to effectively suppress the liquid oil from flowing into the housing 13.

  (3) The upstream end 15 a of the gas inlet 15 is located on the virtual plane 24 including the lower surface of the bottom wall 14. According to such a configuration, the upstream end 15 a of the gas inlet 15 does not protrude below the lower surface of the bottom wall 14. For this reason, when determining the formation position of the gas inlet 15, the upstream end 15a of the gas inlet 15 interferes with the intake camshaft, the cam of the exhaust camshaft, the cam cap, etc. that are located directly below the bottom wall 14. No need to consider. Therefore, the freedom degree of the formation position of the gas inflow port 15 can be raised. Further, since the upstream end 15a of the gas inlet 15 does not protrude below the lower surface of the bottom wall 14, the bottom wall 14 can be disposed close to the cam shaft. For this reason, the overall height of the cylinder head cover 12 can be lowered, and as a result, the overall height of the internal combustion engine mounted on the vehicle can be lowered.

In addition, the said embodiment can also be changed as follows, for example.
For example, in a state where the internal combustion engine is mounted on the vehicle and the portion of the concave groove 142 located below the gas inlet 15 is less likely to move along the lower surface of the bottom wall 14. Therefore, the groove can be omitted for the portion.

-The gas inlet can also have a circular cross section. In this case, the concave groove may have an annular cross section corresponding to the shape of the gas inlet.
Another groove can be formed on the outer peripheral side of the groove 142 on the bottom surface of the bottom wall 14. That is, the concave groove can be formed in double or triple. In this case, it is possible to further suppress the liquid oil that has moved along the lower surface of the bottom wall 14 from flowing into the gas inlet 15 through the concave groove 142.

  The upstream end 15 a of the gas inlet 15 can be set above the virtual plane 24 including the lower surface of the bottom wall 14. Further, the upstream end 15 a of the gas inlet 15 can be set below the virtual plane 24.

  As shown in FIG. 5, the inner peripheral surface of the convex portion 341 can be formed so as to be closer to the central axis C of the gas inlet 35 toward the upstream side. Further, as shown in FIG. 6, the outer peripheral surface of the convex portion 441 can be formed so as to be separated from the central axis C of the gas inlet 45 toward the upstream side. Moreover, as shown in FIG. 7, the outer peripheral surface of the convex part 541 can also be made into step shape. In accordance with this, the concave groove 542 can be stepped. In these cases, the widths X1, X2, and X3 of the concave grooves 342, 442, and 542 that open to the lower surface of the bottom walls 34, 44, and 54 are increased while suppressing an increase in the area of the upper surfaces of the convex portions 341, 441, and 541. can do. Accordingly, a wide space inside the housing can be secured, and the liquid oil that has moved along the bottom surfaces of the bottom walls 34, 44, 54 passes over the concave grooves 342, 442, 542, and the gas inlets 35, Inflowing into 45 and 55 can be more effectively suppressed.

  As shown in FIG. 8, a stepped portion 643 directed upward may be formed around the gas inlet 65 on the lower surface of the bottom wall 64. Even in this case, the liquid oil that has moved along the lower surface of the bottom wall 64 hardly flows into the gas inflow port beyond the stepped portion 643, and the oil falls by its own weight from the front of the stepped portion 643. Will be. Further, in the stepped portion 643, the stepped portion 643 serves as a barrier, and the flow rate of the gas flowing into the housing indicated by the arrow A in FIG. 8 flows in the vicinity of the central axis C of the gas inlet 65 indicated by the arrow B. It is smaller than the gas flow rate. For this reason, the liquid oil that has traveled to the front of the stepped portion 643 along the lower surface of the bottom wall 64 is hardly taken away from the gas inlet 65 into the housing by the gas flowing along the stepped portion 643.

  -The oil separator can be separated from the cylinder head cover.

  DESCRIPTION OF SYMBOLS 11 ... Oil separator, 12 ... Cylinder head cover, 13 ... Housing, 131 ... Housing main body, 132 ... Top wall, 14, 34, 44, 54, 64 ... Bottom wall, 141, 341, 441, 541 ... Projection, 142, 342, 343, 442, 542 ... concave groove, 15, 35, 45, 55, 65 ... gas inlet, 15a ... upstream end, 16 ... gas outlet, 17 ... gas flow path, 18 ... first separator plate, 19 DESCRIPTION OF SYMBOLS ... Gap, 20 ... Oil discharge port, 21 ... 2nd separating plate, 22 ... Gap, 23 ... Oil passage, 24 ... Virtual plane, 643 ... Step part.

Claims (3)

An oil separator for separating mist-like oil contained in blow-by gas of an internal combustion engine,
Comprising a bottom wall formed with a gas inlet;
Wherein the periphery of the gas inlet in the lower surface of the bottom wall, and grooves with a single member is formed by bending the bottom wall of the one member,
The inner peripheral surface of the concave groove on the gas inlet side is closer to the central axis of the gas inlet toward the upstream side, and the inner peripheral surface of the concave groove on the side opposite to the gas inlet side is The upstream side is away from the central axis of the gas inlet,
Oil separator. The upstream end of the gas inlet is located on or above a virtual plane including the lower surface of the bottom wall,
The oil separator according to claim 1 . The oil separator is provided integrally with a cylinder head cover of an internal combustion engine,
The oil separator according to claim 1 or 2 .