JP6520613B2 - Oil mist separator - Google Patents

Description

  The present invention relates to an oil mist separator that separates and removes oil in blowby gas generated by a diesel engine in a separator chamber.

  In a diesel engine, an oil mist separator is provided in the blowby gas path to remove oil in the blowby gas. However, during low rotation and low load operation such as idling, the intake pipe negative pressure is small and the blowby gas is The flow rate taken in is small. In this state, if the pressure loss of the oil mist separator is large, the flow rate of the intake blow-by gas will be further reduced, and the pressure in the crankcase may increase greatly. When the crankcase internal pressure increases, the oil pressure at the bottom of the crankcase also increases, so there is a risk that oil leakage may occur from each seal of the engine.

  Therefore, in order to suppress an increase in the crankcase internal pressure, it is conceivable to reduce the pressure loss of the oil mist separator. However, if the pressure loss is reduced, for example, if the oil mist separator is of the collision type, the collision speed of the oil mist to the collision plate decreases, so the oil mist collection performance of the oil mist separator is lowered. For this reason, it is not possible to efficiently remove the oil mist at the time of high rotation and high load operation with a large blow-by gas flow rate and a large amount of generation of oil mist. As a result, the oil consumption by carrying out will increase. Conversely, if the pressure loss of the oil mist separator is increased in order to remove oil mist efficiently during high revolution and high load operation, the crankcase internal pressure will increase during low revolution and low load operation.

  In this regard, Patent Document 1 proposes a blow-by gas reduction device provided with a sub-passage without a control valve as a bypass in addition to a normal blow-by gas passage provided with a control valve. According to this device, according to the crankcase internal pressure, the switching valve is selectively switched to any of the above passages, and the crankcase internal pressure is set to a predetermined value by the sensor during low rotation / low load operation where the crankcase internal pressure is relatively large. When it is detected that the pressure in the crankcase is exceeded, the auxiliary passage is opened, and the rise in the crankcase internal pressure is suppressed. On the other hand, at high rotation / high load operation where the crankcase internal pressure is relatively small, the blow-by gas passage is opened by the switching valve. Thus, according to this device, the crankcase internal pressure can be properly maintained.

Japanese Utility Model Publication No. 59-159715

  However, although the device of Patent Document 1 can properly maintain the crankcase internal pressure by switching with the switching valve, the oil mist separator itself does not change in any operation, so the oil mist collection performance is improved. I can not let it go.

  Further, the device of Patent Document 1 requires a switching valve to selectively switch the blow-by gas passage and the sub-passage in addition to the additional sub-passage, and further, a diaphragm for operating the same and a vacuum tank A switching means consisting of a solenoid valve, a pressure switch, etc. is required, and the system is complicated and the number of parts is large.

  Therefore, the present invention has a simple configuration and can suppress an increase in crankcase internal pressure by reducing its own pressure loss during low rotation and low load operation where restrictions on crankcase internal pressure are severe, and oil mist An object of the present invention is to provide an oil mist separator that can improve the oil mist collection performance during high rotation and high load operation with a large amount of generation.

In order to solve the above-mentioned problems, the invention according to claim 1 is an oil mist separator for separating and removing oil in blowby gas generated by a diesel engine in a separator chamber, and an impact plate provided in the separator chamber , together with the provided below of the impact plate facing the impact plate in the separator chamber, a first nozzle and a second nozzle for injecting blow gas into the collision plate, the blow-by gas flowing from the separator chamber with the flow rate to open the opening of the second nozzle at a low flow rate below a predetermined value, opening and closing the flow rate of the blowby gas flowing from the separator chamber to close the opening of the second nozzle at a high flow rate exceeding a predetermined value and the valve, and the bottom partition plate that forms the separator chamber, the flow of blow-by gas into the separator chamber And an oil discharge hole for discharging oil separated in the separator chamber, wherein the flow inlet is formed in the direction in which the first nozzle and the second nozzle are aligned. The oil discharge hole is disposed on the side closer to the axis of the first nozzle than the axis of the two nozzles, and the axis of the oil discharge hole is the second in the direction in which the first nozzle and the second nozzle are arranged. The gist is that the nozzle is disposed on the opposite side of the axial center of the first nozzle with respect to the axial center of the nozzle .
According to a second aspect of the present invention, in the first aspect of the present invention, the second nozzle is connected to a storage portion for storing the float valve, which is the on-off valve, so as to be able to move up and down. And moving up and down between a raised position closing the opening of the second nozzle and a lowered position opening the opening of the second nozzle according to the flow rate of blow-by gas flowing into the separator chamber. Do.
The invention according to claim 3 is the invention according to claim 2, wherein an inflow hole for blowby gas is formed in the bottom plate of the accommodation portion, and the float valve has a main body facing the inflow hole. A closing portion provided on the upper side of the main body and closing the opening of the second nozzle, and projecting downward to the lower side of the main body and mounted on the outer peripheral side of the inflow hole of the bottom plate of the housing portion A summary of the present invention is to provide a plurality of legs.
The invention according to claim 4 is the invention according to claim 2 or 3, wherein a plurality of the second nozzles are provided, and each opening of the plurality of the second nozzles is introduced into the separator chamber. The present invention is summarized as closing by the float valve sequentially when the flow rate of the blowby gas exceeds the predetermined value .

According to the oil mist separator of the present invention, a collision plate provided in the separator chamber, and a first nozzle and a first nozzle for injecting blow-by gas to the collision plate while being provided in the separator chamber under the collision plate opposite to the collision plate The nozzle of the second nozzle is opened when the flow rate of the blow-by gas flowing into the separator chamber is lower than a predetermined value, and the flow rate of the blow-by gas flowing into the separator chamber exceeds the predetermined value. And an on- off valve for closing the opening of the second nozzle at the time of flow rate . As a result, at the time of low rotation and low load operation where the flow rate of blowby gas is small, both the first nozzle and the second nozzle are opened, and the opening area of the entire nozzle is large, so the pressure loss of the oil mist separator becomes small. The rise in crankcase internal pressure can be suppressed. On the other hand, at the time of high rotation and high load operation with a large flow of blow-by gas, the opening / closing valve closes the opening of the second nozzle and the opening area of the entire nozzle decreases, so the pressure loss of the oil mist separator increases and oil mist Collection performance is improved. Further, the configuration can be simplified as compared with the conventional configuration in which the blowby gas passage and the sub passage are provided on the downstream side of the oil mist separator.
The second nozzle is connected to a storage portion that accommodates the float valve, which is the on-off valve, so that the float valve can be moved up and down, and the float valve can change the flow rate of the blowby gas flowing into the separator chamber. When raising and lowering between the raised position closing the opening of the second nozzle and the lowered position opening the opening of the second nozzle, the correlation between the weight of the float valve and the flow rate of the blowby gas flowing into the separator chamber Thus, the opening of the second nozzle can be opened and closed, so that the number of parts can be reduced and the configuration can be further simplified.
Furthermore, an inlet hole for blowby gas is formed in the bottom plate of the housing portion, and the float valve has a main body, a closing portion, and a plurality of legs, depending on the flow rate of the blowby gas. Thus, the float valve can be operated sensitively.

According to the oil mist separator of the reference embodiment , the blow-by gas is introduced from the tangential direction into the separator body by being connected to the first centrifugal separator, the second centrifugal separator, and the cylindrical separator body of the first centrifugal separator And a second inlet pipe connected to the cylindrical separator body of the second centrifugal separator to introduce blowby gas from the tangential direction into the separator body, a first centrifugal separator and a second centrifugal separator, and And an on-off valve for opening and closing the opening of the second introduction pipe according to the flow rate of the blow-by gas flowing into the centrifugal separator. As a result, at the time of low rotation and low load operation where the flow rate of blowby gas is small, both the first introduction pipe and the second introduction pipe are opened, and the opening area of the entire introduction pipe is large. It becomes smaller and the rise in crankcase internal pressure is suppressed. On the other hand, during high-speed, high-load operation with a large flow of blow-by gas, the opening / closing valve closes the opening of the second introduction pipe and the opening area of the entire introduction pipe decreases, so the pressure loss of the oil mist separator increases. The oil mist collection performance is improved. Further, the configuration can be simplified as compared with the conventional configuration in which the blowby gas passage and the sub passage are provided on the downstream side of the oil mist separator.

The invention will be further described in the following detailed description referring to the non-limiting examples of exemplary embodiments according to the invention and with reference to the several figures referred to, but like reference numerals in the drawings. Similar parts are shown throughout the several figures.
It is the schematic of the oil mist separator of embodiment of this invention, (a) is the state at the time of low flow volume of blow-by gas, (b) shows the state at the time of high flow volume of blow-by gas. It is a top view of the on-off valve of FIG. It is sectional drawing by the AA cutting line of FIG. It is a general view of the blowby gas recirculation path of an engine. It is the schematic of the oil mist separator in reference form. FIG. 6 is a schematic view showing an oil mist separator in still another embodiment of the present invention. FIG. 6 is a schematic view showing an oil mist separator in still another embodiment of the present invention.

  The matter set forth herein is illustrative and is for the purpose of illustrating the embodiments of the invention and is intended to provide the most effective and easily understood explanation of the principles and conceptual features of the invention. It is stated for the purpose of providing what seems to be. In this respect, it is not intended to show the structural details of the present invention beyond what is necessary for a fundamental understanding of the present invention, and some forms of the present invention will It will be apparent to those skilled in the art how it may be embodied in practice.

Hereinafter, embodiments of the present invention will be described based on the drawings.
The oil mist separator separates and removes the oil in the blowby gas generated by the diesel engine. In this embodiment, the oil mist separator is a collision type in which the blowby gas collides with the collision plate to separate and remove the oil. Moreover, the oil mist separator here illustrates what was externally attached to the upper part of the head cover.

  In FIG. 1, in the oil mist separator 1A, the separator chamber 11 is partitioned by a partition plate 12 in the horizontal direction, and in the separator chamber 11, a collision plate 13 made of a filter is provided. Non-woven fabric, woven fabric, porous body or the like is used as the filter. The collision plate 13 is disposed above the partition plate 12 so as to be separated by a predetermined distance, and the first nozzle 14 and the second nozzle 15 are separated by a predetermined distance from the partition plate 12 at a position facing the collision plate 13. It is attached. Among them, the second nozzle 15 is provided with an on-off valve 16 that opens and closes the opening of the second nozzle 15 according to the flow rate of the blowby gas BG. That is, the first nozzle 14 does not have the on-off valve 16, and the second nozzle 15 has the on-off valve 16.

  In the present embodiment, the collision plate 13 made of a filter (specifically, a breathable filter) is illustrated, but the invention is not limited thereto. For example, the collision plate 13 is integrally or separately provided on a wall forming the separator chamber 11 An impact plate may be employed, which consists of the walls being made (specifically, non-air-permeable walls). Further, for example, a filter (specifically, a breathable filter) may be attached to the collision surface side of a collision plate made of a wall (specifically, a non-permeable wall). Furthermore, in the present embodiment, the common collision plate 13 disposed to be opposed to the first and second nozzles 14 and 15 is exemplified, but the present invention is not limited to this. For example, to oppose the first nozzle 14 The first collision plate may be provided, and the second collision plate may be provided to be opposed to the second nozzle 15.

  The bore diameter of each of the nozzles 14 and 15 is set corresponding to the desired blow-by gas flow rate and pressure loss, and in the present embodiment, a nozzle of 2 to 6 mm is used. However, the nozzle diameter is not limited to this numerical value. The oil mist separator 1A is often provided with several nozzles, but for convenience of explanation, in FIG. 1, one first nozzle 14 and one second nozzle 15 are provided. Indicates

  A bottom partition plate 17 is formed below the separator chamber 11, and the blowby gas passage 37 is moved upward from the crankcase 35 shown in FIG. 3 to the side of the bottom partition plate 17 and flows into the head cover 39. An inlet 18 into which the gas BG flows is formed. At an upper portion of the separator chamber 11, an outlet 19 is provided, through which the blowby gas BG flowing in the separator chamber 11 flows out. The hole diameter of the outlet 19 is set corresponding to the desired blow-by gas flow rate and pressure loss, and in the present embodiment, it is formed to 10 to 20 mm in relation to the nozzle diameter. However, the hole diameter of the outflow port 19 is not limited to this numerical value.

  The second nozzle 15 is connected to a housing portion 20 which accommodates the on / off valve 16 so as to be able to move up and down between a raised position (see FIG. 1B) and a lowered position (see FIG. 1A). In the central portion of the bottom plate 21 of the housing portion 20, an inflow hole 22 into which the blowby gas BG flows in from below is provided. Furthermore, the bottom partition plate 17 is provided with an oil discharge hole 23 through which the oil OL separated and removed in the separator chamber 11 is discharged, and it extends downward from the discharge hole 23 and the oil in the lower portion of the crankcase 35 An oil discharge passage 24 communicating with the pan 44 is formed.

  The on-off valve 16 is a float valve formed of synthetic resin, metal or the like, and as shown in FIG. 2, the outer surface of the upper surface of the main body 16a having a substantially cruciform plan view substantially has a spherical surface. The hemispherical closing part 16b is formed in the shape integrally mounted. The on-off valve 16 is disposed in the housing portion 20 so that the main body 16 a faces the inflow hole 22. The upper surface of the closing portion 16b is formed substantially in a spherical surface, so the closing portion 16b abuts on the entire periphery of the opening of the second nozzle 15 even if the opening and closing valve 16 rises to the raised position and the opening 16 It can be closed securely. However, the float valve is not necessarily limited to this shape, and the upper portion may have a conical shape or the like. The on-off valve 16 is further provided with a rectangular plate-like leg portion 16c projecting downward at four peripheral end portions of the bottom surface of the main body 16a. The bottom surface of the leg portion 16c is placed in contact with the outer peripheral side of the inflow hole 22 of the bottom plate 21 of the accommodation chamber 20 when the on / off valve 16 is at the lowered position when the engine is stopped and the blowby gas BG has a low flow rate. Ru.

Next, the flow of the blowby gas BG in the blowby gas reflux path of the diesel engine provided with the oil mist separator 1A configured as described above will be described.
In the engine 31 and the blowby gas return path shown in FIG. 4, the blowby gas BG generated in the combustion chamber 32 of the engine 31 leaks into the crankcase 35 from the gap between the outer peripheral surface of the piston 33 and the inner peripheral surface of the cylinder 34 Thereafter, the blowby gas passage 37 is moved upward from the lower part of the cylinder block 36 by the intake pipe negative pressure, and flows into the cylinder head cover 39 from the cylinder head 38. Then, after the oil component is separated and removed while passing through the oil mist separator 1A attached to the head cover 39, it merges with the fresh air on the upstream side purified by the air cleaner 41, and compresses the intake air to a combustion chamber It is sent to a turbocharger 42 which is an intake supercharger which is forcibly sent to 32, further cooled by an intercooler 43, and returned to a combustion chamber 32 through an intake pipe passage 40.

Next, the operation of the oil mist separator 1A will be described.
Since the intake pipe negative pressure is small at a low flow rate such as idling with the engine 31 idling, the on-off valve 16 provided below the second nozzle 15 is, as shown in FIG. Since the weight of the on-off valve 16 is larger than the suction force due to the intake pipe negative pressure, it is placed on the bottom plate 21. At this time, the main body 16a is separated from the bottom plate 21 and faces the inflow hole 22, and a gap is formed between the legs 16c. Therefore, the path from the lower side of the bottom plate 21 through the inflow hole 22 to the inside of the storage chamber 20 is in a communicating state. Therefore, the blowby gas BG which has flowed from below the bottom plate 21 is guided from the inflow holes 22 through the gaps between the legs 16 c into the storage chamber 20 and is further ejected from the second nozzle 15 into the separator chamber 11. It is possible. On the other hand, since the first nozzle 14 is not provided with the open / close valve 16 at the lower side and is always in the open state, the blowby gas BG which has flowed in from the inflow port 18 is always in the state capable of spouting into the separator chamber 11. As described above, when the blowby gas BG is at a low flow rate, both the first nozzle 14 and the second nozzle 15 are open and can be jetted.

  On the other hand, when the engine 31 has high rotation and high load and high flow rate, as shown in FIG. 1 (b), the on-off valve 16 provided below the second nozzle 15 is a bottom plate The upper surface of the hemispherical body 16 b abuts on the opening at the lower end of the second nozzle 15. As a result, the opening of the second nozzle 15 is closed, so that the blowby gas BG below the bottom plate 21 is interrupted halfway along the path from the inflow hole 22 of the bottom plate 21 to the second nozzle 15 and the separator chamber 11. . Therefore, when the blowby gas BG is at a high flow rate, only the first nozzle 14 is open and can be jetted into the separator chamber 11.

Next, the operation of the oil mist separator 1A will be described.
Since the oil mist separator 1A is a collision type, the pressure loss of the oil mist separator itself and the oil mist collection performance are determined by the total opening area of the first nozzle 14 and the second nozzle 15 combined. Here, in the oil mist separator 1A, (pressure loss = pressure of inlet 18−pressure of outlet 19).

  Now, when the engine 31 is in a low flow rate, low load, low flow state, the suction pipe negative pressure is small, so the suction force of the blowby gas BG is small and the blowby gas BG tends to stay in the crankcase 35. However, as described above, the first nozzle 14 and the second nozzle 15 are both open during low rotation and low load operation, and the opening area of the entire nozzle is large. For this reason, since the speed at which the blowby gas BG is ejected from each nozzle and collides with the collision plate 13 is small and the pressure loss of the oil mist separator 1A is small, the blowby gas BG flows smoothly. As a result, the internal pressure of the crankcase 35 is prevented from rising due to the large amount of blowby gas BG staying in the crankcase 35. Then, the internal pressure of the crankcase 35 is increased, so that the pressure of the lubricating oil at the bottom of the crankcase 35 is increased to prevent the occurrence of oil leakage from the lubricating portion.

  On the other hand, assuming that both nozzles are set to be always open in this manner, the pressure loss of the oil mist separator 1A itself is maintained even when the engine 31 is in a high flow rate condition with high rotation and high load. As it is small as it is, the collection performance of the oil mist in the blowby gas BG will not be improved.

  However, in the oil mist separator 1A of the present embodiment, the opening of the second nozzle 15 is closed by the on-off valve 16 when the engine 31 is in a high flow rate state of high rotation and high load, and the opening area as the entire nozzle Is halved compared to low speed and low load. For this reason, the pressure loss of the oil mist separator 1A is large, and the blowby gas BG collides with the collision plate 13 at high speed, so the collection rate of the oil mist increases. Therefore, the collection performance of the oil mist becomes high at the time of high rotation and high load operation where the generation amount of the oil mist is large, and thereby, it is possible to prevent the increase of the oil consumption amount due to carry-out.

  In the oil mist separator 1A shown in FIG. 1, one first nozzle 14 and one second nozzle 15 are provided. For example, two first nozzles 14 and a second nozzle are shown. Assuming that one nozzle 15 is provided, it is assumed that all nozzles have the same conditions such as the same diameter and the same weight, and a total of three nozzles were opened before switching the on-off valve 16. The openings of the respective second nozzles 15 are closed, and only the two first nozzles 14 are opened. Therefore, the opening area of the entire nozzle becomes 2/3 after switching. When the number of the first nozzles 14 and the number of the second nozzles 15 are all one, the opening area of the entire nozzle becomes half after switching. As described above, by varying the number of nozzles of each of the first nozzle 14 and the second nozzle 15, the opening area of the entire nozzle after switching of the on-off valve 16 can be varied.

  When the number of each of the first nozzle 14 and the second nozzle 15 is one, the opening area of the entire nozzle rapidly decreases to 1⁄2 immediately after the switching valve 16 is switched, and the pressure loss of the oil mist separator 1A is It increases rapidly. On the other hand, if a plurality of nozzles are provided as the second nozzle 15 and the weights and the like of the float valves are made different from one another so that the nozzles are sequentially closed, the entire nozzle immediately after switching of the on-off valve 16 is completed. It is also possible to make the change of the open area of the lens smooth.

Next, although the above-mentioned oil mist separator 1A is made into a collision type, a cyclone type is mentioned as a reference form .
The cyclone-type oil mist separator 1B separates and removes the oil in the blowby gas BG by swirling centrifugal separation, and as shown in FIG. 5, the first centrifugal separation is performed in the separator chamber 51 of the oil mist separator 1B. The vessel 52 and the second centrifugal separator 53 are arranged side by side in the horizontal direction. The bottom plate portion 54 partitioning the separator chamber 51 is provided with an inlet 55 into which the blowby gas BG flows, and above the separator chamber 51 is provided an outlet 66 through which the blowby gas BG flows out.

  Each centrifugal separator 52, 53 is vertically installed, and its cylindrical separator body 56 is formed of a container 57 shaped like an inverted truncated cone. An inflow hole 58 is provided in the upper part of the peripheral wall of the container 57, and one end sides of the first introduction pipe 67 and the second introduction pipe 68 in the separator chamber 51 are connected to the inflow hole 58, and the first and second introduction The blowby gas BG having flowed through the pipes 67 and 68 is designed to flow tangentially to the peripheral wall. An oil discharge hole 60 is formed in the central portion of the bottom plate portion 54 of the separator main body 56, and a gas discharge hole 62 is formed in the central portion of the upper lid portion 61. Furthermore, in the internal space of the separator body 56, a discharge pipe 63 penetrating the gas discharge hole 62 is dropped along the central axis, and the lower end of the discharge pipe 63 extends to a position above the bottom plate 54 by a predetermined distance. ing. And in the middle of the 2nd introduction pipe 68 of the 2nd centrifugal separator 53, the accommodation part 20 which accommodated the on-off valve 16 which consists of a float valve is connected. The discharge pipe 63 penetrating the lid portion 61 upward is further connected to the discharge passage 65 after passing through the upper plate portion 64 of the separator chamber 51. The discharge passage 65 connected to the discharge pipe 63 from the first centrifugal separator 52 and the second centrifugal separator 53 merges into one along the way, and the merging portion is the above-described outlet 66. In addition, in this embodiment, although the cylindrical shape of the main body 56 having an inverted truncated conical shape is illustrated, the present invention is not limited to this, and for example, a cylindrical main body having a cylindrical shape may be adopted.

  Here, the first introduction pipe 67 of the first centrifugal separator 52 in which the on-off valve 16 is not provided is always in the open state. On the other hand, in the second inlet pipe 68 of the second centrifugal separator 53 provided with the open / close valve 16, when the inflow of blowby gas increases, the open / close valve 16 floats up by the negative pressure of the intake pipe to open the second inlet pipe 68 When it is closed by touching it, it is closed.

  In the oil mist separator 1B configured as described above, the blowby gas BG that has flowed into the separator chamber 51 from the inflow port 55 passes through the first and second introduction pipes 67 and 68 and is separated from the inflow hole 58 of the separator main body 56 After flowing into the inside from a direction tangential to the peripheral wall of the main body 56, it turns along the peripheral wall. Among the blowby gas BG, heavy oil mist collides with the peripheral wall by the centrifugal force and condenses, becomes liquid oil OL, flows down along the peripheral wall and flows down, and is discharged from the oil discharge hole 60 of the bottom plate portion 54, crankcase 35 is returned to the lower oil pan 44.

  On the other hand, the blowby gas BG from which the oil mist is separated and removed is lightweight and flows downward while swirling at the center side of the swirling flow, moves upward from the opening at the lower end of the discharge pipe 63 and passes through the discharge passage 65 and the outlet. After being discharged from 66, it is returned to the combustion chamber 32 through the intake pipe passage 40.

  Similarly to the collision type oil mist separator 1A, the cyclone type oil mist separator 1B also has the first introduction pipe 67 and the second introduction pipe 68 when the engine 31 is in a low flow rate state with low rotation and low load. The blow-by gas BG is jetted into the inside of the separator main body 56 of each of the centrifugal separators 52 and 53 in the separator chamber 51 from both the introduction pipes 67 and 68. In this state, since the opening area of the entire introduction pipe is large, the pressure loss which is the difference between the pressure at the inlet 55 of the oil mist separator 1B and the pressure at the outlet 66 is small, and the internal pressure of the crankcase 35 rises. Is reduced.

  On the other hand, when the engine 31 is in a high flow rate, high load, high flow rate state, the opening of the second introduction pipe 68 is closed by the on-off valve 16 and the blowby gas BG is separated by the first centrifugal via the first introduction pipe 67. It will be ejected only to the inside of the separator body 56 of the separator 52. As a result, the opening area of the entire introduction pipe is reduced to half at the low flow rate, so the pressure loss of the oil mist separator 1B is increased, and the blowby gas BG is vigorously ejected from the first introduction pipe 67 into the separator body 56 Be done. Thereby, the collection performance of the oil mist at the time of high rotation and high load operation with a large amount of generated oil mist is enhanced.

  In the oil mist separator 1B shown in FIG. 5, two centrifuges are provided in the separator chamber 51, but three or more centrifuges may be provided. Further, in the present embodiment, the first and second centrifugal separators 52 and 53 are provided in the separator chamber 51 into which the blowby gas flows, but the present invention is not limited to this. As shown in FIG. 1, one end of each of the first and second introduction pipes 67 and 68 may be connected to the inflow portion 70 into which the blowby gas flows.

  By the way, although the oil mist separator of each said embodiment has illustrated what was externally attached by the cylinder head cover 39, an oil mist separator may be externally attached to places other than this. Furthermore, it is not limited to external attachment, and for example, as shown in FIG. 6, it may be built in the cylinder head cover 39. Alternatively, as shown by the broken line in FIG. 7, it may be built in the side separator chamber of the crankcase 35 or the cylinder block 36. In the case of external attachment, it is possible to easily replace the internal parts such as the collision plate 13 in the oil mist separator.

  Further, although the on-off valve 16 in each of the above embodiments performs the opening and closing control of the nozzle utilizing the natural force of causing the float valve to float by the difference between the intake pipe negative pressure and the float valve weight. The internal pressure of the crankcase 35 or the rotational speed or load of the engine 31 is detected by a sensor, and the signal is sent to the on-off valve 16 side. It may control the opening and closing operation of the opening.

  Furthermore, in the case of practicing the present invention, a diaphragm valve for adjusting pressure may be provided in the blowby gas path or the like.

  The foregoing examples are for illustrative purposes only and are not to be construed as limitations on the present invention. While the present invention has been described by way of exemplary embodiments, it is understood that the words used in the description and illustration of the present invention are illustrative and exemplary rather than restrictive. Changes may be made within the scope of the appended claims without departing from the scope or spirit of the invention in its form, as detailed herein. While the specification herein has been directed to specific structures, materials, and examples, the present invention is not intended to be limited to the particulars disclosed herein, but rather is as follows: It shall cover all functionally equivalent structures, methods, and uses within the scope.

  The invention is not limited to the embodiments detailed above, but various modifications or alterations are possible within the scope of the claims of the invention.

  The present invention is widely used as a technology for separating and removing oil in blowby gas generated by a diesel engine.

  1A, 1B; oil mist separator, 11: separator chamber, 13: collision plate, 14: first nozzle, 15: second nozzle, 16: open / close valve, 16a; main body, 16b; closing part, 16c; leg, 51 Separator chamber, 52; first centrifuge, 53; second centrifuge. 56; separator body, 67; first inlet tube, 68; second inlet tube, BG; blow-by gas

Claims (4)

An oil mist separator for separating and removing oil in blowby gas generated by a diesel engine in a separator chamber,
A collision plate provided in the separator chamber;
A first nozzle and a second nozzle which are provided in the separator chamber opposite to the collision plate and below the collision plate and which blows a blowby gas to the collision plate;
With flow rate of blow-by gas flowing from the separator chamber to open the opening of the second nozzle at a low flow rate below a predetermined value, the high flow when the flow rate of the blowby gas flowing from the separator chamber exceeds a predetermined value And an on- off valve for closing the opening of the second nozzle ,
The bottom partition plate forming the separator chamber is provided with an inlet for introducing a blowby gas into the separator chamber, and an oil discharge hole for discharging the oil separated in the separator chamber,
The inflow port is disposed closer to the axial center of the first nozzle than the axial center of the second nozzle in the direction in which the first nozzle and the second nozzle are arranged,
The oil discharge hole is disposed such that the axis thereof is opposite to the axis of the first nozzle with respect to the axis of the second nozzle in the direction in which the first nozzle and the second nozzle are arranged. An oil mist separator characterized by being . The second nozzle is connected to a housing portion that houses the float valve, which is the on-off valve, so as to be able to move up and down.
The float valve is raised and lowered between a raised position closing the opening of the second nozzle and a lowered position opening the opening of the second nozzle according to the flow rate of blow-by gas flowing into the separator chamber. The oil mist separator according to claim 1. A blow-by gas inflow hole is formed in the bottom plate of the housing portion,
The float valve is provided with a main body facing the inflow hole, a closing portion provided on the upper side of the main body and closing an opening of the second nozzle, and protrudingly provided on the lower side of the main body The oil mist separator according to claim 2, further comprising: a plurality of legs mounted on an outer peripheral side of the inflow hole of the bottom plate. A plurality of said second nozzles are provided,
The oil mist separator according to claim 2 or 3, wherein the openings of the plurality of second nozzles are sequentially closed by the float valve when the flow rate of blow-by gas flowing into the separator chamber exceeds the predetermined value. .

Images