JP7171268B2 - oil separator - Google Patents

Description

The present invention relates to an oil separator for separating oil mist contained in gas from the gas.

Patent Literature 1 discloses an oil separator that separates oil mist from blow-by gas. Hereinafter, the oil separator disclosed in Patent Document 1 will be briefly described using the reference numerals used in Patent Document 1 in parentheses.

The housing (20) has an internal space, and the internal space is partitioned by the partition member (31) to create a separation chamber (43) above the partition member (31) and an injection chamber (43) below the partition member (31). 44) are formed. A spindle shaft (51) is erected at the bottom of the injection chamber (44), and the spindle shaft (51) vertically penetrates the partition member (31). The spindle shaft (51) is inserted into a spindle (52), and the spindle (52) is rotatably supported on the spindle shaft (51). Inside the separation chamber (43), a plurality of separation discs (63) are mounted around the spindle (52), and the separation discs (63) are stacked in the axial direction of the spindle (52). In the injection chamber (44), a nozzle (53) protrudes from the outer peripheral surface of the spindle (52).

When oil is supplied from the engine to the nozzle (53), the oil is jetted in the circumferential direction from the nozzle (53). The separation disc (63) is rotationally driven together with the spindle (52) by the injection pressure of the oil. Further, when the blow-by gas is supplied from the engine to the central portion of the separation disc (63), the blow-by gas passes through the gap between the separation discs (63) to the outside. Oil is trapped in the gap.

The oil injected by the nozzle accumulates at the bottom of the injection chamber (44) and is discharged to the engine through the oil outlet (21a) provided at the bottom of the injection chamber (44).

WO2016/139715

However, when the amount of oil accumulated at the bottom of the injection chamber (44) increases, the oil discharge port (21a) is submerged in oil. As a result, pulsation occurs in the flow of oil, preventing the oil from smoothly flowing into the oil discharge port (21a). Furthermore, the difference between the pressure in the injection chamber (44) and the pressure in the engine causes the oil to flow backward, which may raise the oil level in the injection chamber (44). The pulsation means intermittent obstruction of the oil flow due to gas in the engine intermittently flowing backwards against the oil flow and passing through the oil discharge port (21a).

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to prevent pulsation and reverse flow of oil so that the oil smoothly flows into the oil discharge port.

In order to solve the above problems, the oil separator for separating the oil mist from the gas containing the oil mist is provided in a housing having an internal space and in the internal space so as to be rotatable about a vertical axis. a plurality of separation discs provided around the spindle to rotate together with the spindle and stacked with gaps in the axial direction of the spindle; and an outer peripheral surface of the spindle below the separation disc. a nozzle projecting from the nozzle for rotating the spindle and the separation disc by injecting oil; a partition member provided in the internal space and dividing the internal space into an upper separation chamber and a lower injection chamber; an oil guard that hangs down from the lower surface of the partition member in the injection chamber and is provided in a cylindrical shape; the housing is provided with an oil discharge port and a ventilation path that communicate from the outside to the inside of the housing; Inside the housing, the air passage opens at a position above the liquid level of the oil reservoir at the bottom of the housing and the oil discharge port, the spindle vertically penetrates the partition member, and the separation disk separates the separation. The nozzle is arranged inside the oil guard, the oil discharge port and the air passage communicate with the injection chamber from the outside of the housing, and the air passage extends from the lower end of the oil guard in the injection chamber. It opens at a position above and outside the oil guard .

As described above, the housing is provided with the air passage, and the air passage opens in the housing at a position above the oil discharge port, so the pressure in the housing is adjusted by the air passage. Therefore, pulsation and backflow of oil do not occur at the oil outlet, and the oil smoothly flows into the oil outlet.
In addition, since the air passage is opened at a position above the oil discharge port in the housing, the oil collected at the bottom of the housing does not easily flow into the air passage, and the opening of the air passage in the housing does not sink into the oil pool. Therefore, the pressure inside the housing can be reliably adjusted by the air passage.

As described above, since the opening of the air passage in the injection chamber is provided at a position above the lower end of the oil guard, the oil injected by the nozzle does not enter the air passage. Therefore, the air passage is not clogged with oil, and the pressure in the injection chamber is reliably adjusted by the air passage. Therefore, the oil smoothly flows into the oil outlet.

The oil separator is provided in the internal space spaced upward from the partition wall member, and is provided in the internal space spaced upward from the middle partition member and a middle partition wall member that divides the internal space into upper and lower parts, a partition wall portion that vertically partitions the internal space; and an upper partition member that is provided in the internal space at a distance from the partition portion, vertically partitions the internal space, and has an opening vertically penetrating therethrough; a partition portion provided between the middle partition member and the partition wall, and partitioning a region between the middle partition member and the partition wall into an introduction passage and a chamber; and an outlet port communicating with the upper region of the upper partition member, wherein the middle partition member includes the introduction passage and the central portion of the separation disc. and a first communication hole for communicating between the injection chamber and the chamber. A second communication hole is provided for communication, and the partition member is provided with an oil hole for communication between the injection chamber and the separation chamber.

According to the above, when the gap between the separation discs is clogged, gas is not introduced from the inlet port into the introduction passage. When doing so, gas is introduced into the injection chamber through the vent passage. The gas flows through the oil holes into the separation chamber. The gas is discharged from the outlet port via the first communication hole, the first chamber, the second communication hole and the opening. Therefore, even if the gap between the separation discs becomes clogged, gas can still flow through the oil separator.

The oil separator further includes a PCV valve that is provided between the upper partition member and the partition and adjusts the degree of opening of the opening.

According to the above, when the gap between the separation discs is clogged, the gas introduced into the injection chamber through the air passage flows through the oil hole, the separation chamber, the first communication hole, the first chamber, the second communication hole and the It is discharged from the outlet port via the opening. Therefore, even if the gap between the separation discs becomes clogged, the PCV valve can regulate the gas flow rate.

The opening of the air passage within the housing faces upward.

According to the above, even if sloshing occurs on the liquid surface of the oil accumulated at the bottom inside the housing, a large amount of oil does not flow into the ventilation path, and the ventilation path is not completely clogged with oil. Therefore, the pressure in the injection chamber is reliably adjusted by the air passage, and the oil smoothly flows into the oil discharge port.

The position of the opening of the air passage on the outside of the housing is above the position of the oil outlet on the outside of the housing.

According to the present invention, the pressure in the housing is adjusted by the air passage, pulsation and reverse flow of the oil at the oil outlet can be prevented, and the oil smoothly flows into the oil outlet.

1 is a schematic diagram of a closed crankcase ventilation system; FIG. It is the perspective view which looked down on the oil separator. Fig. 2 is an exploded perspective view of an oil separator in an exploded view; It is a top view of an oil separator. FIG. 5 is a cross-sectional view of a cross section showing a cut portion by VV in FIG. 4; 6 is an enlarged view of the upper part of FIG. 5; FIG. FIG. 6 is an enlarged view of the central portion of FIG. 5; FIG. 6 is an enlarged view of the lower portion of FIG. 5; FIG. 6 is a cross-sectional view of a cross section showing a cut portion by IX-IX in FIG. 5; It is the perspective view which looked down on the lower case. FIG. 6 is an enlarged view of the lower portion of FIG. 5; FIG. 4 is a cross-sectional view of the lower portion of the oil separator using the redesigned lower case; It is the perspective view which looked down on the lower case whose design was changed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, although various technically preferable limitations are attached to the embodiments described below in order to carry out the present invention, the scope of the present invention is not limited to the following embodiments and illustrated examples.

1. Closed Crankcase Ventilation System As shown in FIG. 1 , a closed crankcase ventilation system 1 has an oil separator 2 , a breather pipe 3 , a gas supply pipe 5 and an oil supply pipe 10 . The oil separator 2 is attached to the side of the engine 4 . A gas supply pipe 5 is connected to the engine 4 and the oil separator 2 , and blow-by gas discharged from the crankcase of the engine 4 is supplied to the oil separator 2 through the gas supply pipe 5 . The blow-by gas supplied from the crankcase of the engine 4 to the oil separator 2 contains oil mist. The oil separator 2 separates oil mist from the blow-by gas.

A breather pipe 3 is connected between an upper portion of the oil separator 2 and an intake side passage 6 of the engine 4 . The separated blow-by gas discharged from the oil separator 2 is recirculated to a portion of the intake side passage 6 that connects the air filter 7 and the turbocharger 8 . The recirculated blow-by gas is mixed with fresh air from the air filter 7 . A mixture of blow-by gas and fresh air is compressed by turbocharger 8 . After that, the air-fuel mixture is cooled by the charge cooler 9 and then supplied to the engine 4 .

An oil supply pipe 10 is connected between the lower portion of the oil separator 2 and the engine 4 , and working oil sent out from the engine 4 is supplied to the oil separator 2 through the oil supply pipe 10 . The flow of the working oil supplied to the oil separator 2 is used for the power of the oil separator 2, and the power operates the oil separator 2 (particularly, the rotor unit 50, which will be described later). The working oil supplied to the oil separator 2 is lubricating oil used in the engine 4 . When the oil separator 2 is operated by the working oil, the oil mist is separated from the blow-by gas. The separated oil mist is mixed with the working oil inside the oil separator 2 . The mixed oil is discharged from the oil separator 2 to the engine 4. In this embodiment, pulsation and reverse flow of the oil discharged from the oil separator 2 are prevented so that the oil smoothly flows from the oil separator 2 to the engine 4 . Before describing the mechanism for suppressing oil pulsation and backflow, the configuration of the oil separator 2 will be described.

2. Overview of Oil Separator The oil separator 2 will be described with reference to FIGS. 2 to 11. FIG.
As shown in FIGS. 2 to 5, the oil separator 2 includes a housing 20, a lower partition member 31, a middle partition member 32, an upper partition member 33, a rotor unit 50 and a PCV valve 90. FIG. Housing 20 has lower case 21 , upper case 22 and top cover 23 . The housing 20 is formed by assembling a lower case 21, an upper case 22 and a top cover 23, and an internal space is formed inside the housing 20. As shown in FIG. A lower partition member 31, a middle partition member 32, a partition wall portion 22a, and an upper partition member 33 are provided inside the housing 20, and the inner space of the housing 20 is divided into the lower partition member 31, the middle partition member 32, the partition wall portion 22a, and the upper partition member. separated by 33. The rotor unit 50 , the PCV valve 90 , and the like are assembled to the housing 20 while being accommodated within the internal space of the housing 20 .

Hereinafter, unless otherwise specified, the axial direction refers to the direction parallel to the rotation axis of the rotor unit 50, the circumferential direction refers to the circumferential direction around the rotation axis of the rotor unit 50, and the radial direction indicates a direction orthogonal to the rotation axis of the rotor unit 50. As shown in FIG. When the oil separator 2 is attached to the engine 4, the rotating shaft of the rotor unit 50 extends vertically.

3. Housing and Sections Inside It The housing 20 and its internal space will be described, and how the internal space of the housing 20 is divided by the lower partition member 31, the middle partition member 32, the partition portion 22a, and the upper partition member 33 will be described.

As shown in FIGS. 3 and 5 to 8, the upper case 22 is provided in a cylindrical shape, and the upper and lower surfaces of the upper case 22 are open. A partition wall 22a is provided in the upper part inside the upper case 22, and the hollow of the upper case 22 is partitioned into a space above and below the partition wall 22a by the partition wall 22a.

An inlet port 24 is provided in a portion of the upper case 22 below the partition wall portion 22a. This inlet port 24 is connected to the gas supply pipe 5 (see FIGS. 1 and 3). Therefore, the blow-by gas is introduced from the engine 4 through the gas supply pipe 5 and the inlet port 24 into a portion of the internal space of the housing 20 below the partition wall portion 22a (specifically, an introduction passage 41, which will be described later). be.

Inside the upper case 22, a middle partition member 32 is provided at a position below and apart from the disk-shaped partition 22a. A peripheral portion of the middle partition member 32 is attached to the inner peripheral surface of the upper case 22 , and the hollow of the upper case 22 is partitioned vertically by the middle partition member 32 . A cylindrical fitting portion 32b protrudes downward from the central portion of the lower surface of the intermediate partition member 32 . The hollow of the fitting portion 32b opens at the upper surface of the middle partition member 32 and at the lower end of the fitting portion 32b. At the opening at the lower end of the fitting portion 32b, support portions 32d are provided radially from the center of the opening at the lower end of the fitting portion 32b to the inner peripheral surface of the fitting portion 32b. Since the support portions 32d are provided radially, the flow holes 32e are formed in the support portions 32d. Therefore, the hollow of the fitting portion 32b communicates downward through the hole of the support portion 32d. The support portion 32d supports the upper end of a spindle shaft 51, which will be described later.

A partition portion 22 c is provided in a protruding state on the lower surface of the partition portion 22 a , and the lower end of the partition portion 22 c abuts against the upper surface of the middle partition member 32 . As shown in FIG. 9, the partition 22c partitions the space between the middle partition member 32 and the partition 22a into an introduction passage 41 and a first chamber 42 surrounding the introduction passage 41. As shown in FIG. The inlet port 24 communicates the outside of the upper case 22 with the introduction path 41 . As shown in FIGS. 5 and 6, the flow hole 32e allows the introduction path 41 and the space below the middle partition member 32 to communicate with each other. Blow-by gas is introduced from the engine 4 through the gas supply pipe 5 and the inlet port 24 into the introduction passage 41. It is sent to the lower side of the partition member 32 .

A second communication hole 22d is formed in the partition wall 22a (see FIG. 9 in particular), and the second communication hole 22d vertically penetrates the partition wall 22a. The position of the second communication hole 22d is outside the partition portion 22c, and the second communication hole 22d communicates the first chamber 42 with the upper hollow portion of the partition wall portion 22a. On the other hand, the upper side of the introduction path 41 is blocked by the partition wall 22a, and the hollow above the partition wall 22a and the introduction path 41 are partitioned by the partition wall 22a.

As shown in FIGS. 5 and 6, a plurality of first communication holes 32c penetrate vertically through the peripheral portion of the middle partition member 32. As shown in FIGS. The position of the first communication hole 32c is outside the partition part 22c, and the first communication hole 32c communicates the first chamber 42 with the lower hollow of the middle partition member 32. As shown in FIG.

As shown in FIGS. 5, 7 and 8, a lower partition member 31 is attached to the lower end of the upper case 22, and the lower opening of the upper case 22 is closed by the lower partition member 31. As shown in FIGS. A lower partition member 31 is spaced downward from the middle partition member 32 , and a separation chamber 43 is formed between the middle partition member 32 and the lower partition member 31 . This separation chamber 43 is a part of the hollow inside the upper case 22 . In the separation chamber 43, the oil gas mist is separated by the rotor 60 from the blow-by gas introduced from the inlet port 24 through the introduction passage 41, the fitting portion 32b, and the flow hole 32e into the rotor 60 of the rotor unit 50, which will be described later. be done.

As shown in FIGS. 5 and 6 , an upper partition member 33 is attached to the upper end of the upper case 22 , and the upper opening of the upper case 22 is closed by the upper partition member 33 . The upper partition wall member 33 is spaced upward from the partition wall portion 22a, and a second chamber 45 is formed between the upper partition wall member 33 and the partition wall portion 22a. An opening 33a is formed in the central portion of the upper partition member 33, and the opening 33a penetrates the upper partition member 33 vertically.

A top cover 23 is attached to the upper end of the upper case 22 . The top cover 23 covers the upper partition member 33 from above, and the peripheral edge of the upper partition member 33 is sandwiched between the lower end of the top cover 23 and the upper end of the upper case 22 . A top cover 23 is formed in a dome shape, and a third chamber 46 is formed inside the top cover 23 . The third chamber 46 and the second chamber 45 are partitioned by the upper partition member 33, and the opening 33a allows the second chamber 45 and the third chamber 46 to communicate with each other.

An outlet port 23 a is provided in the top cover 23 , and the outlet port 23 a communicates the outside of the top cover 23 with the third chamber 46 . This outlet port 23 a is connected to the breather pipe 3 , and the separated blow-by gas in the third chamber 46 is discharged to the intake side passage 6 through the third chamber 46 and the breather pipe 3 .

As shown in FIGS. 5, 7 and 8, the lower case 21 is attached to the lower end of the upper case 22. As shown in FIGS. The lower case 21 covers the lower partition member 31 from below, the upper end of the lower case 21 is fitted into the opening of the lower end of the upper case 22, and the lower case 21 and the upper case 22 are connected by bolts or the like. Fixed. A peripheral portion of the lower partition member 31 is sandwiched between the upper end of the lower case 21 and the lower end of the upper case 22 . The lower case 21 is formed in the shape of a bottomed box with an open top. A lower partition member 31 partitions an injection chamber 44 in the lower case 21 and a separation chamber 43 in the upper case 22 . A through hole 31 a through which the rotor unit 50 is passed is formed in the central portion of the lower partition member 31 .

A cylindrical oil guard 31g that hangs down is provided on the lower surface of the lower partition member 31 . An oil guard 31g surrounds the through hole 31a.
A plurality of oil holes 31c are formed in the lower partition member 31 at predetermined intervals in the circumferential direction. These oil holes 31c are arranged around the oil guard 31g. Oil separated from the blow-by gas flows from the separation chamber 43 into the injection chamber 44 through these oil holes 31c.

4. Path of Blow-by Gas As shown by arrows in FIG. It flows through the hole 32c, the first chamber 42, the second communication hole 22d, the second chamber 45, the opening 33a, and the third chamber 46 in this order, and is discharged from the outlet port 23a to the breather pipe 3.

5. Oil Inlet Path, Oil Drainage Port, and Ventilation Path As shown in FIGS. 5, 8 and 10, the lower case 21 is formed with an oil exhaust opening 21a and an airflow path 21d. The oil discharge port 21 a is open on the side surface of the lower case 21 and communicates with the injection chamber 44 . The oil outlet 21a is connected to the engine 4, and the oil in the injection chamber 44 is discharged to the engine 4 through the oil outlet 21a.

One end 21e of the air passage 21d opens at a position above the oil discharge port 21a on the side surface of the lower case 21, and the opening and the oil discharge port 21a are vertically aligned. 21 d of ventilation paths are extended toward the injection chamber 44 from the side surface of the lower case 21, and are bent upwards on the way. The other end 21f of the air passage 21d opens upward in the injection chamber 44. As shown in FIG. The opening of the other end 21f is arranged above the lower end of the oil guard 31g and outside the oil guard 31g.

The inner bottom surface of the lower case 21 slopes downward toward the oil discharge port 21a. A boss 21b protrudes from the inner bottom surface of the lower case 21 . An oil introduction passage 21c is formed in the boss 21b. The oil introduction path 21c is drilled downward from the upper surface of the boss 21b and branched laterally to extend to the side surface of the lower case 21. One end of the oil introduction path 21c opens on the side surface of the lower case 21, The other end of the oil introduction path 21c opens on the upper surface of the boss 21b. An oil introduction passage 21c is connected to the oil supply pipe 10 (see FIGS. 1 and 3) on the side surface of the lower case 21. As shown in FIG. Accordingly, working oil is introduced from the engine 4 through the oil supply pipe 10 into the oil introduction passage 21c.

A mesh strainer 35 for filtering the working oil is provided in the middle of the oil introduction passage 21c. By removing the plug 35a from the lower end of the lower case 21, the lower end of the oil introduction passage 21c is opened and the strainer 35 can be removed from the oil introduction passage 21c.

6. Rotor Unit and Working Oil As shown in FIGS. 3, 5, 7 and 8, the rotor unit 50 is a mechanism for separating oil mist from blow-by gas. The rotor unit 50 includes a spindle shaft 51, a spindle 52, a rotor 60, a plurality of nozzles 53, and the like.

The spindle shaft 51 extends vertically in the lower case 21 and the upper case 22 and vertically penetrates the through hole 31 a of the lower partition member 31 . The lower end of the spindle shaft 51 is inserted into the upper end of the oil introduction passage 21c. The upper end portion of the spindle shaft 51 is supported by the support portion 32d. Inside the spindle shaft 51 , a first oil supply passage 51 b is formed along the centerline of the spindle shaft 51 . The lower end of the first oil supply path 51b opens at the lower end surface of the spindle shaft 51, and the first oil supply path 51b communicates with the oil introduction path 21c. An upper portion of the first oil supply path 51 b branches radially outward at an intermediate portion of the spindle shaft 51 , and an end of the first oil supply path 51 b opens on the outer peripheral surface of the spindle shaft 51 .

A spindle shaft 51 is inserted into a cylindrical spindle 52 , which also passes vertically through the through hole 31 a of the lower partition member 31 . The upper portion of the spindle shaft 51 protrudes upward from the upper end of the spindle 52 and the lower portion of the spindle shaft 51 protrudes downward from the lower end of the spindle 52 . A gap is formed between the outer peripheral surface of the spindle shaft 51 and the inner peripheral surface of the spindle 52, and the gap is the second oil supply passage 52a. The second oil supply path 52a is supplied with the working oil introduced into the oil introduction path 21c through the first oil supply path 51b.

The spindle shaft 51 is inserted into a lower bush 55 at the lower end of the spindle 52 , and the lower bush 55 is sandwiched between the outer peripheral surface of the spindle shaft 51 and the inner peripheral surface of the spindle 52 . The spindle shaft 51 is inserted into an upper bush 56 at the upper end of the spindle 52 , and the upper bush 56 is sandwiched between the outer peripheral surface of the spindle shaft 51 and the inner peripheral surface of the spindle 52 .

A radial load of the spindle 52 is received by the spindle shaft 51 through the bushes 55 and 56, and the spindle 52 is supported by the spindle shaft 51 in a rotatable state. A nut 58 is screwed onto the upper end portion of the spindle shaft 51, and the lower portion of the spindle shaft 51 is inserted into a bush 54 provided on the upper surface of the boss 21b. A washer 57 , an upper bush 56 , a spindle 52 and a lower bush 55 are sandwiched between the nut 58 and the bush 54 , and the thrust load of the spindle 52 is received by the bush 54 and the nut 58 .

Slight clearances are provided between lower bushing 55 and bushing 54, between upper bushing 56 and washer 57, and between washer 57 and nut 58 to allow the spindle 52 and bushings 55 and 56 to move slightly in the axial direction. exist between Specifically, when the rotor 60 rotates, the spindle 52 and bushes 55 and 56 rise along the axial direction, and when the rotor 60 stops, the spindle 52 and bushes 55 and 56 descend.
A small gap exists between the inner peripheral surface of the spindle 52 and the upper bush 56, and part of the working oil in the second oil supply passage 52a flows out of the spindle 52 through the gap. Hereinafter, the outflowing working oil is referred to as separating oil.

When the spindle 52 is supported by the spindle shaft 51, the spindle 52 is passed through the through hole 31a of the lower partition member 31, and extends upward from the through hole 31a. It extends downward.

A plurality of nozzles 53 protrude from the outer peripheral surface of the lower portion of the spindle 52 at regular intervals (for example, intervals of 120°) in the circumferential direction. These nozzles 53 are attached obliquely downward with respect to the axis of the spindle 52 . An injection port 53a is formed on the peripheral surface of the nozzle 53 near the tip. The injection ports 53 a are directed in the circumferential direction around the axis of the spindle 52 . The hollow portion of the nozzle 53 communicates with the second oil supply passage 52a at the base end portion of the nozzle 53 . The working oil in the second oil supply passage 52a is supplied into the nozzle 53 and ejected from the injection port 53a. The spindle 52 rotates due to the injection pressure of the working oil. Therefore, these nozzles 53 inject oil and generate power for rotating the spindle 52 by the injection pressure of the oil.

These nozzles 53 are arranged inside the injection chamber 44 and inside the oil guard 31g. The working oil injected from the injection port 53a of the nozzle 53 is sprayed onto the oil guard 31g. Therefore, the operating oil does not splash outside the oil guard 31g and does not enter the opening of the other end 21f of the air passage 21d or the oil hole 31c.

The operating oil sprayed onto the oil guard 31g drips from the oil guard 31g to the bottom of the injection chamber 44 . The dripped operating oil flows into the oil outlet 21 a and is discharged to the engine 4 . Since the injection chamber 44 communicates with the inside of the engine 4 through the air passage 21d, the gas pressure in the injection chamber 44 and the gas pressure in the engine 4 are adjusted. Therefore, the working oil flowing through the oil discharge port 21a does not pulsate and the flow becomes smooth.

As shown in FIG. 8 , working oil accumulates at the bottom of the injection chamber 44 , and the position of the liquid surface 101 of the oil reservoir 100 is affected by the pressure inside the engine 4 . The higher the pressure inside the engine 4, the higher the liquid level 101 of the oil reservoir 100, and conversely, the lower the pressure inside the engine 4, the lower the liquid level 101 of the oil reservoir 100. However, since the opening of the other end 21f of the air passage 21d is provided at a higher position, particularly above the lower end of the oil guard 31g, the liquid surface of the oil reservoir is higher than the opening of the other end 21f of the air passage 21d. 21f of the other end of the air passage 21d can be prevented from being immersed in oil. In particular, since the opening of the other end 21f of the ventilation path 21d is directed upward, it is possible to further prevent the opening from being submerged in oil. Also, even if sloshing occurs on the liquid surface 101 of the oil reservoir 100, a large amount of oil does not flow into the opening of the other end 21f of the air passage 21d, and the opening is not completely clogged with oil. Therefore, the pressure in the injection chamber 44 is reliably adjusted by the air passage 21d.

Since the opening of the other end 21f of the air passage 21d is directed upward, even if the vehicle is tilted, the liquid surface 101 of the oil reservoir 100 is higher than the opening of the other end 21f of the air passage 21d as shown in FIG. 21d, it is difficult for the oil in the oil reservoir 100 to flow into the opening of the other end 21f of the air passage 21d.

Next, the rotor 60 will be described with reference to FIGS. 3 and 5 to 8. FIG. The rotor 60 is the part that separates the oil mist from the blow-by gas in the separation chamber 43 . The outer shape of the rotor 60 is cylindrical, and the center of the rotor 60 is a space 62. The center space 62 penetrates the rotor 60 in the vertical direction, and the top and bottom of the center space 62 are open. there is The spindle 52 is inserted into this central space 62, and the spindle 52 and the rotor 60 are connected to each other. Therefore, the rotor 60 rotates together with the spindle 52 due to the oil injection pressure from the nozzle 53 .

This rotor 60 comprises a separation disk group 61 , an upper holder 71 , a lower holder 72 and a disk holder 73 .
The separation disc group 61 is composed of a plurality of separation discs 63 , and these separation discs 63 are stacked in the axial direction of the spindle 52 . Separating disc 63 is provided in a shape obtained by rotating about an axis in an upside-down V that is spaced radially outwardly from the axis of spindle 52 . Therefore, an opening is formed in the central portion of the separation disk 63 . As the separating discs 63 are stacked, a central space 62 consisting of these openings is formed.

Since the separation disk 63 is a V-shaped rotating body, the outer circumference side portion 64 of the separation disk 63 is formed into a truncated cone shape with the apex above the center of the separation disk 63, and the inner circumference of the separation disk 63 is formed. The side portion 65 is shaped like a frusto-conical surface with the apex below the center of the separating disc 63 . The inner peripheral portion 65 slopes radially outward and upward, and the outer peripheral portion 64 slopes radially outward and downward from the outer edge of the inner peripheral portion 65 . Since the separating disc 63 is bent at the boundary between the inner peripheral portion 65 and the outer peripheral portion 64, the rigidity of the separating disc 63 is improved. In addition, the length from the inner peripheral edge of the separation disk 63 to the outer peripheral edge of the separation disk 63 along the surface of the separation disk 63 can be increased, and the surface area of the separation disk 63 can be increased.

A plurality of convex portions (for example, ribs, protrusions, etc.) are provided on the upper surface or the lower surface of the separation disk 63 or on both surfaces thereof. The convex portion abuts on the adjacent separation disc 63 to form a gap between the adjacent separation discs 63, and the width of the gap is determined by the height of the convex portion. 3 and 5 to 8, the separation discs 63 are drawn with a space therebetween, but the actual space is extremely narrow.

A plurality of separation discs 63 as described above are assembled to the upper holder 71, the lower holder 72, and the disc holding portion 73 to assemble the rotor 60. As shown in FIG.

The disk holding portion 73 is inserted into the central opening of the separation disk 63 and the separation disk 63 is supported by the disk holding portion 73 . A spindle 52 is inserted into the disc holding portion 73 and the spindle 52 is fixed to the disc holding portion 73 . A plurality of slits are radially provided in the disc holding portion 73 , and these slits communicate from the inner circumference to the outer circumference of the disc holding portion 73 . Therefore, the cavity 73 a inside the disc holding portion 73 communicates with the gap between the separation discs 63 through the plurality of slits of the disc holding portion 73 .

These separation discs 63 are sandwiched between the upper holder 71 and the lower holder 72 , and the connecting portion 74 (see FIG. 3) connects the outer peripheral portion of the upper holder 71 and the outer peripheral portion of the lower holder 72 . Thereby, the separation disk 63 is held between the upper holder 71 and the lower holder 72 .

The outer peripheral edge of the lower holder 72 is separated from the inner peripheral surface of the upper case 22 , and a gap 43 a is formed between the outer peripheral edge of the lower holder 72 and the inner peripheral surface of the upper case 22 .

An opening 72 a is formed in the central portion of the lower holder 72 . This opening 72 a overlaps under the central opening of the lowermost separation disk 63 , and this opening 72 a serves as the lower end opening of the central space 62 . The spindle 52 is fitted into the opening 72 a of the lower holder 72 , and the periphery of the opening 72 a is fixed to the lower outer peripheral surface of the spindle 52 and the lower end of the disc holding portion 73 . Therefore, the opening 72a is closed by the spindle 52. As shown in FIG.

An opening 71 a is formed in the central portion of the upper holder 71 . This opening 71 a overlaps the central opening of the separation disk 63 of the uppermost layer, and this opening 71 a becomes the upper end opening of the central space 62 . The edge of this opening 71a is connected to the upper end of the disk holding portion 73, and the hollow portion 73a inside the disk holding portion 73 communicates with the opening 71a. The fitting portion 32b of the middle partition member 32 is inserted into the opening 71a of the upper holder 71, and the hollow portion of the fitting portion 32b communicates with the cavity portion 73a through the communication hole 32e. there is Therefore, the blow-by gas introduced into the inside of the housing 20 through the inlet port 24 flows into the hollow portion 73a through the introduction passage 41, the hollow of the fitting portion 32b, and the circulation hole 32e.

The blow-by gas that has flowed into the hollow portion 73 a flows radially outward through the plurality of slits of the disc holding portion 73 and further flows into the gaps between the separation discs 63 . The blow-by gas that has flowed into the gaps between the separation discs 63 flows radially outward. Here, the blow-by gas that has flowed into the gap between the separation discs 63 is subjected not only to pressure from the upstream side, but also to centrifugal force due to the rotation of the rotor 60 . Further, the centrifugal force due to the rotation of the rotor 60 generates a suction pressure for sucking the blow-by gas in the introduction passage 41 into the hollow portion 73a, thereby increasing the flow velocity of the blow-by gas.

On the other hand, the separation oil that has flowed into the hollow portion 73a through a small gap between the inner peripheral surface of the spindle 52 and the upper bush 56 is also pushed radially outward through the plurality of slits of the disc holding portion 73 together with the blow-by gas. and then flows into the gaps between the separation discs 63 . The oil present in the gaps between the separation discs 63 spreads over the surfaces of the separation discs 63 due to centrifugal force, and an oil film is formed on the surfaces of the separation discs 63 . They are the upper surface of the inner peripheral side portion 65 and the lower surface of the outer peripheral side portion 64 .

When the blow-by gas flows through the gaps between the separation discs 63 , oil mist contained in the blow-by gas is absorbed by the oil film on the surfaces of the separation discs 63 . As a result, the oil mist in the blow-by gas is caught by the separation disc 63, and the oil mist is separated from the blow-by gas. As described above, the separating discs 63 have a large surface area and a large number of the separating discs 63 are stacked, so the oil mist is easily separated.

In addition, not only the oil separated from the blow-by gas, but also the separation oil flowing out from the second oil supply passage 52a is a component of the oil film on the surface of the separation disc 63. An oil film is formed. Since the oil mist in the blow-by gas is absorbed by such an oil film, the separation efficiency of the oil mist is high.

The oil adhering to the surface of the separation disc 63 flows to the outer peripheral side along the surface of the separation disc 63 due to centrifugal force. At the outer peripheral edges of the separation discs 63, the oil adhering to the surfaces of the separation discs 63 flies outward from the gaps between the separation discs 63 due to the centrifugal force.

As indicated by arrows in FIG. 8 , the flying oil adheres to the inner peripheral surface of the upper case 22 . The oil flows down while adhering to the inner peripheral surface of the upper case 22 . The oil flows into the injection chamber 44 through the oil hole 31c. A part of the oil mixes with the working oil in the injection chamber 44 and flows into the oil discharge port 21a. The remaining oil is discharged to the engine 4 through the air passage 21d. The oil flowing through the air passage 21 d is separated from the blow-by gas, and the amount of the oil is smaller than the working oil injected from the nozzle 53 . Therefore, since the amount of oil flowing through the ventilation path 21d is small, the ventilation path 21d is not blocked by the oil.

7. Blow-by Gas Discharge Route and PCV Valve after Separation Blow-by gas from which oil mist is separated in the gap between the separation discs 63 is ejected outward from the gap between the separation discs 63 . The blow-by gas rises in the separation chamber 43 and flows into the first chamber 42 through the first communication hole 32c, as shown in FIG. The blow-by gas flows from the first chamber 42 into the second chamber 45 through the second communication hole 22d. The blow-by gas is discharged from the second chamber 45 to the breather pipe 3 through the opening 33a of the upper partition member 33, the third chamber 46 and the outlet port 23a. The blow-by gas is thereby circulated to the engine 4 .

As shown in FIGS. 5 and 6, the PCV valve 90 adjusts the flow rate of blow-by gas flowing from the second chamber 45 to the third chamber 46 . As a result, the intake pressure of the engine 4 and the pressure on the crankcase side are appropriately adjusted.

A PCV valve 90 is mounted within the second chamber 45 . This PCV valve 90 comprises a diaphragm 91 , an upper spring 92 and a lower spring 93 . The diaphragm 91 is an elastically deformable disk-shaped valve body. This diaphragm 91 is accommodated in the second chamber 45 and arranged under the opening 33 a of the upper partition member 33 . The outer edge portion of the diaphragm 91 is joined to the upper surface of the partition wall portion 22a. Since the second communication hole 22 d of the partition wall 22 a is arranged outside the outer edge of the diaphragm 91 , the blow-by gas that has passed through the second communication hole 22 d flows over the diaphragm 91 .

The upper spring 92 is sandwiched between the diaphragm 91 and the upper partition member 33 above the central portion of the diaphragm 91 . The lower spring 93 is sandwiched under the central portion of the diaphragm 91 and between the diaphragm 91 and the partition wall portion 22a. The center portion of the diaphragm 91 is sandwiched between the upper spring 92 and the lower spring 93 , and the center portion of the diaphragm 91 is movably supported by the upper spring 92 and the lower spring 93 .

A pressure regulating hole 22b is formed in the upper case 22, and the pressure regulating hole 22b allows the space below the diaphragm 91 and the outside of the upper case 22 to communicate with each other. Therefore, the space below the diaphragm 91 is kept at atmospheric pressure by the pressure regulating hole 22b.

The flow rate of blow-by gas passing through the opening 33a is adjusted as follows. That is, when the intake pressure (negative pressure) of the engine 4 is excessively high, the central portion of the diaphragm 91 moves upward, so that the degree of opening of the opening 33a decreases and the flow rate of blow-by gas decreases. On the other hand, when the pressure on the crankcase side is high, the central portion of the diaphragm 91 moves downward to increase the degree of opening of the opening 33a, thereby increasing the flow rate of the blow-by gas. Thereby, the flow rate of the blow-by gas is appropriately adjusted by the diaphragm 91 . Also, the pressure in the engine 4, especially in the crankcase, is appropriately regulated.
Note that the PCV valve 90 may not be provided.

8. Advantageous Effects Since the opening of the other end 21f of the air passage 21d is provided at a position above the oil discharge port 21a, the pressure in the injection chamber 44 is adjusted by the air passage 21d. Therefore, the oil smoothly flows into the oil discharge port 21a.
Since the opening of the other end 21f of the air passage 21d is provided at a high position, particularly above the liquid surface 101 of the oil pool 100 and the lower end of the oil guard 31g, the opening of the other end 21f of the air passage 21d Prevents oil immersion. Therefore, the pressure in the injection chamber 44 is reliably adjusted by the air passage 21d.

9. About fail-safe If the gap between the separation discs 63 is clogged with sludge or the like, the blow-by gas from the engine 4 will not flow to the inlet port 24 . In this case, a flow path for blow-by gas can be secured in the oil separator 2 , and the intake pressure of the engine 4 and the pressure on the crankcase side can be appropriately adjusted by the PCV valve 90 .
Specifically, blow-by gas is introduced into the injection chamber 44 from the engine 4 through the air passage 21d and flows into the separation chamber 43 through the oil hole 31c. The blow-by gas passes through the first communication hole 32c, the first chamber 42, the second communication hole 22d, the second chamber 45, the opening 33a, and the third chamber 46 in this order, and then from the outlet port 23a to the breather pipe 3. Ejected. Therefore, a blow-by gas circulation path is secured, and the blow-by gas flow rate is adjusted by the PCV valve 90 .

10. Modifications The lower case 21 described above may be changed to the lower case 121 shown in FIGS. 12 and 13 . This lower case 121 will be described. The lower case 121 is formed in the shape of a bottomed box with an open top. The upper end of the lower case 121 is fitted into the opening at the lower end of the upper case 22 and fixed. A peripheral portion of the lower partition member 31 is sandwiched between the upper end of the lower case 21 and the lower end of the upper case 22 , and the injection chamber 144 and the separation chamber 43 in the lower case 121 are partitioned by the lower partition member 31 . An oil discharge port 121a is provided at the bottom of the lower case 121, and the oil discharge port 121a allows the injection chamber 144 and the outside of the lower case 121 to communicate with each other. This oil discharge port 121a is connected to the engine 4 via a pipe.

A boss 121b protrudes from the inner bottom surface of the lower case 121 . An oil introduction passage 121c is formed in the boss 121b. The oil introduction path 121c is drilled downward from the upper end surface of the boss 121b and bent sideways to extend to the side surface of the lower case 121. One end of the oil introduction path 121c opens at the side surface of the lower case 121, The other end of the oil introduction path 121c opens on the upper surface of the boss 121b. The lower end of the spindle shaft 51 is inserted into the upper end of the oil introduction passage 121c, and the working oil introduced into the oil introduction passage 21c flows into the first oil supply passage 51b and the second oil supply passage 52a.

121 d of ventilation paths are formed in the lower case 121. As shown in FIG. One end 121e of the air passage 121d opens on the side surface of the lower case 121, and the opening and the opening at the end of the oil introduction passage 121c are vertically aligned. An opening at one end 121e of the air passage 121d is connected to the engine 4 by a pipe. The position of the opening of one end 121e of the air passage 121d is above the position of the oil discharge port 121a on the lower surface of the lower case 121. As shown in FIG.
The other end 121f of the air passage 121d opens on the inner surface of the lower case 121, and the opening faces sideways. The opening of the other end 121f is arranged above the lower end of the oil guard 31g and outside the oil guard 31g. Therefore, the working oil injected from the nozzle 53 does not enter the opening of the other end 121f of the air passage 121d, and the oil immersion in the opening can be prevented.

Although several embodiments have been described above, the above embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention.

DESCRIPTION OF SYMBOLS 2... Oil separator 20... Housing 21a... Oil discharge port 21d... Air passage 22a... Partition part 22c... Partition part 22d... Second communication hole 23a... Outlet port 24... Inlet port 31... Lower partition member (partition member)
31g... Oil guard 32... Middle partition member 32c... First communicating hole 32e... Distribution hole 33... Upper partition member 41... Introduction path 42... First chamber (chamber)
43 Separation chamber 44 Injection chamber 52 Spindle 53 Nozzle 63 Separation disk 90 PCV valve 100 Oil pool 101 Liquid level

Claims (5)

An oil separator for separating the oil mist from a gas containing the oil mist,
a housing having an internal space;
a spindle provided in the internal space rotatably around a vertical axis;
a plurality of separation discs provided around the spindle, rotating together with the spindle, and stacked with gaps in the axial direction of the spindle;
a nozzle projecting from the outer peripheral surface of the spindle under the separation disc and rotating the spindle and the separation disc by injecting oil;
a partition member provided in the internal space and partitioning the internal space into an upper separation chamber and a lower ejection chamber;
an oil guard that hangs down from the lower surface of the partition member in the injection chamber and is provided in a cylindrical shape ,
The housing is provided with an oil outlet and an air passage leading from the outside to the inside of the housing,
In the housing, the air passage opens at a position above the liquid surface of the oil reservoir at the bottom of the housing and the oil discharge port,
The spindle vertically penetrates the partition member, the separation disc is arranged in the separation chamber, the nozzle is arranged inside the oil guard, and the oil discharge port and the air passage extend from the outside of the housing. Communicates with the injection chamber, and in the injection chamber, the air passage opens at a position above the lower end of the oil guard and outside the oil guard.
oil separator. a middle partition member provided in the internal space at a distance from the partition member and partitioning the internal space into upper and lower parts;
a partition wall portion provided in the internal space at a distance from the middle partition member and partitioning the internal space into upper and lower parts;
an upper partition wall member provided in the internal space at a distance above the partition wall, partitioning the internal space vertically and having an opening penetrating vertically;
a partition part provided between the middle partition member and the partition wall and partitioning the region between the middle partition member and the partition wall into an introduction passage and a chamber;
The housing is provided with an inlet port that communicates with the introduction path and that introduces the gas, and an outlet port that communicates with the upper region of the upper partition member,
The central partition member is provided with a communication hole for communicating the introduction passage and the central portion of the separation disk, and is provided with a first communication hole for communicating the injection chamber and the chamber,
The partition wall portion is provided with a second communication hole that communicates the chamber with the region between the partition wall portion and the upper partition member,
2. The oil separator according to claim 1 , wherein said partition member is provided with an oil hole for communicating said injection chamber and said separation chamber. 3. The oil separator according to claim 2 , further comprising a PCV valve provided between said upper partition member and said partition wall for adjusting the degree of opening of said opening. 4. The oil separator according to any one of claims 1 to 3 , wherein an opening of said air passage in said internal space faces upward. 5. The oil separator according to any one of claims 1 to 4 , wherein the position of the opening of the air passage on the outside of the housing is higher than the position of the oil outlet on the outside of the housing.

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