JPH05118210A - Oil separator for blowby gas of engine - Google Patents

Abstract

PURPOSE:To keep engine performance proper by not generating an emulsion sludge in the oil separator in the oil separator for the blowby gas of an engine. CONSTITUTION:An oil separator 29 is provided for separating the oil included in a blowby gas 24. A discharge port 34 for discharging a blowby gas 24 after separating the oil from this oil separator 29 is connected to an intake passage 14 downstream from an air cleaner 15 installed in series with an engine 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil separation device for separating oil from blow-by gas generated in an engine for a gas heat pump, which is an air conditioner, for example.

[0002]

2. Description of the Related Art Conventionally, for example, FIG.
Some are configured as shown at 4. This will be explained with reference to the drawings. Reference numeral 1 is a four-cycle engine, which has a crankcase 2, a crankshaft 3, a cylinder 4, and a piston 5, and the crankshaft 3 and the piston 5 are connected rods 6. It is connected. Cylinder 4 above
A cylinder head 7 is mounted on the top, and a space surrounded by the piston 5 and the cylinder head 7 in the cylinder 4 is a combustion chamber 9.

The cylinder head 7 has an intake port 10
And an exhaust port 11 are formed, and these can be opened and closed by a valve (not shown). Further, each valve is appropriately opened and closed by a valve mechanism (not shown) provided on the cylinder head 7. A cylinder head cover 12 that covers this valve mechanism is provided. An intake passage 14 that communicates with the intake port 10 is provided, and an air cleaner 15 is provided at the upstream end of the intake passage 14.
Is provided. The air cleaner 15 is composed of a cleaner case 16 and an element 19 for partitioning an inlet 17 and an outlet 18 formed in the cleaner case 16, and the outlet 18 is formed in a bottom portion of the cleaner case 16 and is provided in the intake passage 14. It communicates with the upstream end. Also,
A throttle 20 is provided in the middle of the intake passage 14.

An oil pan 22 is provided to cover the lower surface of the crankcase 2. Lubricating oil 23 is stored in the oil pan 22, and the lubricating oil 23 lubricates each part of the engine 1. The operation of the engine 1 is the same as the conventional one, and the outside air is exposed to the cleaner case 1 during this operation.
6 is sucked through the inlet 17, passes through the element 19 and is filtered (arrow A in the figure), and then is sucked into the combustion chamber 9 together with the fuel through the intake passage 14 (arrow B in the figure). Burned. Then, the combustion gas is exhausted through the exhaust port 11 (arrow C in the figure).

During operation of the engine 1, the cylinder 4
The blow-by gas 24 flows into the crankcase 2 from the combustion chamber 9 side through the sliding contact surface of the piston 5 (arrow D in the figure). Therefore, a recovery device 25 for recovering the blow-by gas 24 is provided. The recovery device 25 has a labyrinth 27 that communicates with the inside of the crankcase 2 and a recovery passage 28 that communicates from the labyrinth 27 into the cleaner case 16. An oil separator 29 is provided in the air cleaner 15, and the oil separator 29 is composed of an element 30. The blow-by gas 24 in the crankcase 2 passes through the labyrinth 27 and the recovery passage 28 and is sucked into the cleaner case 16 (arrow E in the figure). In this case, the oil contained in the blow-by gas 24 is separated when the blow-by gas 24 passes through the element 30. The blow-by gas 24 thus separated from the oil is sucked into the intake passage 14 together with the outside air (arrow F in the figure), and the combustion chamber 9
Is burned in. Further, the oil separated by the element 30 also flows down along the inner surface of the intake passage 14 and is sent to the combustion chamber 9 to be lubricated again or burned.

[0006]

By the way, in the above-mentioned conventional configuration, when the engine 1 is operated for a long time particularly in a high load region, NO _x is easily generated during combustion and is mixed in the blow-by gas 24. NO _x oxidizes the lubricating oil 23 in the oil pan 22 and deteriorates it early. Next, the oil thus deteriorated is sent to the oil separator 29 through the recovery passageway 28 together with the blow-by gas 24. Here, when the oil is separated from the blow-by gas 24 by the element 30, the element Thirty
Is located inside the cleaner case 16 as described above, the separated blow-by gas 24 directly contacts the outside air sucked into the cleaner case 16,
It is allowed to cool, and condensation will occur here. Then, water generated by this dew condensation is mixed with the oil to generate emulsion sludge. When this occurs, the element 19 of the air cleaner 15 is clogged by this emulsion sludge, and the emulsion sludge is sucked into the combustion chamber 9 together with the intake air to leak the ignition plug. This causes a problem that the startability is reduced.

[0007]

SUMMARY OF THE INVENTION The present invention has been made by paying attention to the above circumstances. In an oil separation device for blow-by gas of an engine, emulsion sludge is prevented from being generated and engine performance is kept good. The purpose is to do so.

[0008]

In order to achieve the above object, the present invention is characterized in that an exhaust passage for exhausting blow-by gas after oil separation from an oil separator has an intake passage downstream of an air cleaner. It is in the point of communicating with.

[0009]

[Operation] The operation of the above configuration is as follows. In the case where the oil separator 29 for separating the oil contained in the blow-by gas 24 is provided, the discharge port 34 for discharging the blow-by gas 24 after the oil separation from the oil separator 29 is provided in the intake passage on the downstream side of the air cleaner 15. It is connected to 14. Therefore, when the engine 1 is operating, the air cleaner 15
It is possible to prevent the outside air sucked in to directly contact the oil separator 29. Therefore, it is possible to prevent the oil separator 29 from being cooled by the outside air to cause dew condensation.
In other words, it is possible to avoid the inconvenience that water generated by dew condensation is mixed with the oil separated by the oil separator 29 to generate emulsion sludge.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to the drawings. In addition, about the structure which these Examples have in common with the said prior art example shown in FIG. 14, the code | symbol is attached | subjected to the figure and description is abbreviate | omitted and only a different structure is demonstrated.

(First Embodiment) FIGS. 1 and 2 show a first embodiment. In FIG. 2, the oil separator 29 has a casing 31 made of sheet metal that covers the element 30, and a suction port 32 for introducing the blow-by gas 24 is formed in the lower portion of the casing 31. The downstream end of the recovery passage 28 formed by the flexible tube 33 is connected. On the other hand, an exhaust port 34 for exhausting the blow-by gas 24 from the casing 31 is formed in the upper part of the casing 31, and the exhaust port 34 is provided in the intake passage 14 downstream of the air cleaner 15 and upstream of the throttle 20. It is connected by a flexible tube 35.

Therefore, when the engine 1 is operating, the outside air drawn through the air cleaner 15 is prevented from directly contacting the oil separator 29. Therefore, the oil separator 29
The occurrence of dew condensation is prevented, that is, the water separated by dew condensation is mixed with the oil separated by the oil separator 29, thereby avoiding the disadvantage that emulsion sludge is generated.

The oil separator 29 will be described in more detail. In FIG. 2, the element 30 is interposed between the suction port 32 and the discharge port 34, and a baffle plate 37 having a plurality of holes 36 is provided between the suction port 32 and the element 30. In addition, another baffle plate 3 having the same configuration as this baffle plate 37
8 is provided so as to cover the element 30 from below. Then, when the blow-by gas 24 is sucked into the casing 31 through the suction port 32 as indicated by an arrow E in each figure, first, the baffle plates 37, 38 are
While passing through each hole 36. At this time, the oil contained in the blow-by gas 24 loses its inertial force, flows down to the bottom of the casing 31, and is stored there. The element 30 allows the air and water vapor in the blow-by gas 24 to pass therethrough, while adsorbing the oil in the blow-by gas 24 and causing the oil to flow down to the bottom of the casing 31 to separate the blow-by gas 24 after the oil separation. Is sucked into the intake passage 14 through the discharge port 34 and the tube 35 as shown by an arrow F in each figure. Then, the oil stored as described above is returned into the oil pan 22 through the recovery passage 28 (arrow G in FIG. 2).

In FIG. 1, the cleaner case 16 on the downstream side of the element 19 in the air cleaner 15 is
A flexible tube 39 is provided in the cylinder head cover 12.
Are connected by. Further, the inside of the cylinder head cover 12 communicates with the inside of the crankcase 2 through a communication passage 40 formed in the cylinder head 7 and the cylinder 4. 41 is a baffle plate. Then, when the engine 1 operates, part of the outside air is in the tube 39 described above.
It is adapted to be introduced into the crankcase 2 through the or communication passage 40 (arrow H in FIG. 1). According to this configuration, the outside air is introduced into the crankcase 2, so that the NO _x of the blow-by gas 24 in the crankcase 2 is reduced.
The concentration becomes low, and the temperature of the lubricating oil 23 is lowered,
Therefore, the deterioration of the lubricating oil 23 is suppressed and the generation of emulsion sludge is prevented.

By the way, when the outside air is introduced into the crankcase 2, the oil content in the gas toward the oil separator 29 increases correspondingly, and it becomes necessary to increase the capacity of the oil separator 29. However, the amount of processing gas increases due to the introduction of the outside air,
The temperature of the oil separator 29 is kept high to some extent. Therefore, the occurrence of dew condensation on the oil separator 29 is prevented,
That is, the generation of emulsion sludge is prevented. As shown by the phantom lines in FIG. 1 and FIG. 2, an oil return pipe 43 that connects the bottom of the casing 31 of the oil separator 29 to the inside of the oil pan 22 is separately provided, and as shown by an arrow I in each figure, the casing 31 Blow-by gas 24
It may be returned to the inside of the oil pan 22 without being affected by.

(Second Embodiment) FIGS. 3 and 4 show a second embodiment. In the figure, the element 3 of the oil separator 29
0 does not adsorb oil as in the first embodiment, but the mesh size of the element 30 and the element 30
It is structured to separate this oil by the effect of the surface treatment. Other configurations and operations are the same as those in the first embodiment.

(Third Embodiment) FIGS. 5 to 7 show a third embodiment. In FIG. 5, a heater 44 is attached to the oil separator 29. On the other hand, the engine 1 is housed in the engine room 46 of the housing 45. A ventilation outlet 45a is formed in a lower portion of the housing 45, and a ventilation inlet 45b is formed in an upper portion thereof, and a ventilation fan 47 for ventilating the inside of the housing 45 is provided in the ventilation outlet 45a.
Is attached. A room temperature sensor 48 for detecting the temperature inside the engine room in the engine room 46 is provided. A water jacket 49 for cooling is formed in the engine 1, and a water temperature sensor 51 for detecting the water temperature of the cooling water 50 in the water jacket 49 is provided. The heater 44 and the ventilation fan 47 are operated by the electronic control means 53 by the detection signals of the room temperature sensor 48 and the water temperature sensor 51. In addition, 54 is a heat insulating material, and this heat insulating material 54 covers the collecting device 25, the collecting passage 28, the tube 35, and the heater 44 from the outside to keep them warm.

6 and 7 show a flow chart of the control means 53, and (P-1) to (P-12) show each step of the program. In FIG. 6, if it is determined that the engine room temperature is lower than a certain set temperature T _A (P-1), the heater 44 is turned on (P-
2) The oil separator 29 is heated to prevent the formation of dew condensation, that is, the generation of emulsion sludge. Next, if it is judged that the temperature in the engine room is higher than a certain set temperature T _B (P-3), the heater 4
4 is turned off (P-4), and excessive heating of the oil separator 29 is prevented. Thereafter, the above steps are sequentially repeated. The set temperatures have a relationship of T _A <T _B.

In FIG. 7, at (P-5), it is determined by the water temperature sensor 51 that the water temperature of the cooling water 50 is equal to or higher than the set temperature T _a , and at (P-6), the temperature in the engine room is set to the set temperature T a. If it is judged to be _b or more, the ventilation fan 47 is turned on (P-7), and the engine 1 as a whole is prevented from becoming too hot.

Next, in (P-8), it is judged that the water temperature of the cooling water 50 is below the set temperature T _c , or the same as above (P-8).
If it is determined in -8) that the water temperature exceeds the set temperature T _c , and in (P-9) that the engine room temperature is below the set temperature T _d , the ventilation fan 47 turns off.
F (P-10), the inside of the engine room 46 is maintained at a predetermined temperature or higher, and the generation of emulsion sludge in the oil separator 29 is prevented. The above set temperatures are
There is a relationship of T _a > T _c and T _b > T _d . Other configurations and operations are the same as those of the first embodiment, but the tube 39 is removed in this embodiment so that part of the outside air is not sucked into the crankcase 2.

(Fourth Embodiment) FIG. 8 shows a fourth embodiment. According to this, the recovery passage 28 communicates the inside of the cylinder head cover 12 with the inside of the oil separator 29. The blow-by gas 24 in the crankcase 2 is sent to the oil separator 29 through the communication passage 40, the cylinder head cover 12, and the recovery passage 28. According to this embodiment, there is an effect that the amount of oil discharged from the engine 1 to the outside can be suppressed to be small. Other configurations and operations are similar to those of the first and second embodiments.

(Fifth Embodiment) FIG. 9 shows a fifth embodiment. According to this, a temperature sensor 56 for detecting the oil separator temperature of the oil separator 29 is provided in place of the room temperature sensor 48 in the third embodiment shown in FIGS. 5, 6 and 7. The heater 44 and the ventilation fan 47 are operated via the control means 53 by the detection signals of the temperature sensor 56 and the water temperature sensor 51.

In the flow chart of the control means 53, in the above-mentioned FIGS. 6 and 7 and the description thereof, the term "temperature in the engine room" is read as "oil separator temperature", and "engine room 46" is read. It is the same as the one with the term "oil separator 29". Other configurations and operations are the same as those in the third embodiment.

(Sixth Embodiment) FIGS. 10 to 12 show a sixth embodiment. 10 and 11, the oil separator 29 includes a main oil separator 55. This main oil separator 5
5 has a casing 57 with a longitudinal axis and a circular cross section, and the inside of the casing 57 is divided into an upper chamber 60, an intermediate chamber 61, and a lower chamber 62 by upper and lower partition plates 58 and 59.

A suction pipe 67 for introducing the blow-by gas 24 is attached to the lower chamber 62, and the downstream end of the recovery passage 28 is connected to the suction pipe 67. The end of the suction pipe 67 on the lower chamber 62 side is a thin nozzle 68, which opens upward. Also, this nozzle 68
A hemispherical reversal plate 69 that faces downward and is opened downward is provided. An oil return pipe 43 is attached to the bottom plate of the casing 57.

The lower partition plate 59 is made of punching metal having many holes. Also, the upper partition plate 5
8 has an annular shape in a plan view, and a partition cylinder 70 extends downward from the hole edge of its inner hole, and the partition cylinder 70 has a small number of holes. The lower end opening of the partition cylinder 70 is closed by a bottom plate 71 near the upper part of the lower partition plate 59, and an oil hole 72 is formed in the bottom plate 71.

Between the outer peripheral wall of the casing 57 and the partition cylinder 70, an element 73 composed of a large number of fine stainless steel wires bent in a zigzag shape is filled. A swirl vane 74 that swirls the blow-by gas 24 is provided in the upper chamber 60, and the swirl vane 74 is attached to an upper plate of the casing 57. The upper plate of the casing 57 has a discharge port 75.
Are formed.

In FIGS. 10 and 11, when the blow-by gas 24 is sucked into the lower chamber 62 through the suction pipe 67, the blow-by gas 24 is accelerated by the nozzle 68 and jets out. Then, the blow-by gas 24 is guided by the reversal plate 69 and suddenly reverses downward. At this time, the oil in the blow-by gas 24 adheres to the inner surface of the reversal plate 69 and is separated from the blow-by gas 24, and this oil is discharged through the oil return pipe 43.

On the other hand, the blow-by gas 24 after being inverted by the inversion plate 69 is the lower partition plate 59 and the element 7.
3 and the partition cylinder 70 in order, and the partition cylinder 7
0 to reach the upper chamber 60, where the swirl vanes 74
Thus, after being rotated around the vertical axis, it is discharged through the discharge port 34. When the blow-by gas 24 passes through the element 73 or is swung by the swirl vanes 74, the oil in the blow-by gas 24 is separated,
This oil passes through the oil hole 72 of the lower partition plate 59 to reach the lower chamber 62, and then is discharged from the oil return pipe 43 and returned to the oil pan 22.

In FIGS. 10 to 12, the recovery device 25 includes a sub oil separator 76. This secondary oil separator 7
Reference numeral 6 denotes a casing 78 having a circular cross-section with a horizontal axis, and the casing 78 has a cylindrical portion 79, one side plate 80 that closes one opening in the axial direction of the cylindrical portion 79, and another side plate 81 that closes the other side opening. It consists of and. The casing 78
The interior of is partitioned by a partition plate 82 into a narrow first chamber 83 and a wide second chamber 84, and the partition plate 82 is formed of punching metal having a large number of holes. The second chamber 8
The element 4 is filled with the element 85 having the same structure as the element 30.

A suction port 86 is formed in the upper portion of the one side plate 80, and a discharge port 75 of the oil separator 29 is used as the suction port 8.
6 is connected by a tube 87. Further, a discharge pipe 88 penetrating the central portions of the one side plate 80, the partition plate 82, and the element 85 is provided, and one end of the discharge pipe 88 is surrounded by the other side plate 81 and the element 85, and the second chamber 84 is provided. Has a discharge port 34 that opens to a partial space and the other end opens to the outside of the casing 78. Further, the oil return pipe 43 is provided below the one side plate 80.
Is attached. In the illustrated example, the oil return pipe 43 extends horizontally from the one side plate 80, but the oil return pipe 43 may be extended obliquely downward from the one side plate 80. For example, oil can be smoothly discharged from the first chamber 83.

The outlet 75 of the main oil separator 55
The blow-by gas 24 that has been sucked into the first chamber 83 through the suction port 86 of the sub oil separator 76 sequentially passes through the partition plate 82, the element 85, and the discharge pipe 88, and is discharged from the discharge port 34. It is returned to the intake passage 14 via the tube 35. In the above case, blow-by gas 24
When the oil passes through the element 85, the oil in the blow-by gas 24 is separated, the oil passes through the partition plate 82, reaches the first chamber 83, and then is discharged from the oil return pipe 43, and the oil pan 22 Returned to. Of the other configurations and operations, the control device 53 and the temperature sensor 56 have the fifth feature.
The configuration is the same as that of the fourth embodiment, and the others are the same as those of the fourth embodiment.

(Seventh Embodiment) FIG. 13 shows a seventh embodiment. According to this, the main oil separator 55 shown in the sixth embodiment is used as the oil separator 29, and the oil separator 29 is arranged above the cylinder head cover 12 and the recovery passage 28. The oil separator 29 may include the main oil separator 55 and the auxiliary oil separator 76 shown in the sixth embodiment. Further, the oil return pipe 43 may be omitted, and in this case, the oil separated by the main oil separator 55 is returned to the inside of the cylinder head cover 12 through the recovery passageway 28. Other configurations and operations are the same as those in the fourth embodiment.

[0034]

According to the present invention, when the oil separator for separating the oil contained in the blow-by gas is provided, the discharge port for discharging the blow-by gas after the oil separation from the oil separator is provided more than the air cleaner. Since it is connected to the intake passage on the downstream side, the outside air drawn into the air cleaner is prevented from directly contacting the oil separator when the engine is operating. Therefore, it is possible to prevent the occurrence of dew condensation in the oil separator, that is, it is possible to avoid the inconvenience that water generated by dew condensation is mixed with the oil separated by the oil separator to generate emulsion sludge. As a result, good engine performance is maintained.

[Brief description of drawings]

FIG. 1 is an overall simplified partial sectional view of a first embodiment.

FIG. 2 is a partially enlarged sectional view of FIG. 1 in the first embodiment.

FIG. 3 is a diagram corresponding to FIG. 1 in a second embodiment.

FIG. 4 is a partially enlarged sectional view of FIG. 3 in a second embodiment.

FIG. 5 is a view corresponding to FIG. 1 in the third embodiment.

FIG. 6 is a flowchart of the third embodiment.

FIG. 7 is a flow chart in the third embodiment.

FIG. 8 is a view corresponding to FIG. 1 in a fourth embodiment.

FIG. 9 is a diagram corresponding to FIG. 1 in a fifth embodiment.

FIG. 10 is a diagram corresponding to FIG. 1 in a sixth embodiment.

FIG. 11 is a sectional view of an oil separator according to a sixth embodiment.

FIG. 12 is a sectional view taken along line 12-12 of FIG. 11 in the sixth embodiment.

FIG. 13 is a diagram corresponding to FIG. 1 in a seventh embodiment.

FIG. 14 is a diagram corresponding to FIG. 1 in a conventional example.

[Explanation of symbols]

 1 Engine 14 Intake Passage 15 Air Cleaner 23 Lubricating Oil 24 Blow-by Gas 29 Oil Separator 34 Discharge Port

Claims (1)

[Claims] 1. An oil separator which is provided with an air cleaner and an intake passage for sequentially passing the outside air introduced into the engine, and which sucks blow-by gas generated in the engine and separates oil contained in the blow-by gas. A blow-by gas oil separation device for an engine, in which an exhaust port for discharging the blow-by gas after oil separation from the oil separator is connected to an intake passage downstream of the air cleaner. apparatus.