JP4983771B2 - Oil-diluted fuel separator - Google Patents

Description

  The present invention relates to an oil-diluted fuel separator, and more particularly, to an oil-diluted fuel oil that can suppress deterioration of lubricating oil in an internal combustion engine by vaporizing and separating fuel components with less energy than in the past. The present invention relates to a fuel separator.

2. Description of the Related Art Conventionally, in order to suppress dilution due to mixing of fuel components in lubricating oil of an internal combustion engine, a method for separating the fuel components by vaporizing them by raising the temperature of the oil is known. (For example, refer to Patent Documents 1 and 2.)
In the above-mentioned patent document 1, the temperature of the lubricating oil is raised by an oil heater provided in the lubricating circuit of the internal combustion engine, and the fuel vaporized out of the fuel mixed in the lubricating oil or the fuel to be mixed into the lubricating oil Increasing the ingredients is disclosed.
Patent Document 2 discloses that a heater for heating the lubricating oil in the oil pan is provided at the bottom of the oil pan to adjust the temperature of the lubricating oil to vaporize the fuel.

JP 2004-190513 A JP 2004-340056 A

However, in Patent Documents 1 and 2, the fuel component in the oil is vaporized by the heater. Usually, the oil temperature during operation of the internal combustion engine is about 130 ° C. at the maximum. More than 30% of the fuel component remains. Further, if the temperature is raised to about 200 ° C., substantially the entire amount of the fuel component contained in the oil can be vaporized, but in this case, there is a problem that the oil itself is deteriorated.
In addition, since the entire oil in the lubrication circuit is heated in any case, the heater has a large structure and the energy required for vaporization separation becomes large.

  The present invention has been made in view of the above-described present situation, and is an oil-diluted fuel capable of suppressing deterioration of lubricating oil of an internal combustion engine by performing vaporization separation of fuel components with less energy than conventional. An object is to provide a separation device.

The present invention is as follows.
1. An oil reservoir for storing lubricating oil of the internal combustion engine;
A wall portion forming a decompression space including a part of the lubricating oil of the oil reservoir in the crank chamber of the internal combustion engine;
A communication path that connects the decompression space and the negative pressure generating portion of the intake system of the internal combustion engine;
A negative pressure tank that is provided in the communication path and stores negative pressure generated in the negative pressure generating section;
And a switching valve for switching supply / stop of the negative pressure stored in the negative pressure tank to the decompression space, provided in the communication path.
2. One end side of a sub communication path connected to a negative pressure actuator that opens and closes a variable intake valve that constitutes a variable intake system of the internal combustion engine is connected to the communication path, and the switching valve includes the communication path and the sub communication path. 1. It is arranged in the communication part of the road, and is configured to switch supply / stop of the negative pressure stored in the negative pressure tank to the decompression space and the negative pressure actuator. The in-oil diluted fuel separator.
3. One end side of a blow-by gas passage connected to an intake pipe constituting an intake system of the internal combustion engine is connected to the decompression space. Or 2. The oil-diluted fuel separator according to claim 1.
4). One end side of an oil supply path for supplying the lubricating oil in the oil reservoir to the lubricated part of the internal combustion engine is disposed in the decompression space or on the lower side of the decompression space. To 3. The oil-diluted fuel separator according to any one of the above.
5. The oil guide further includes an oil guide that guides lubricated oil that has lubricated the lubricated portion of the internal combustion engine to a predetermined portion of the oil reservoir, and the oil reservoir is provided in another predetermined portion that is separated from the predetermined portion of the oil reservoir. One end side of an oil supply path for supplying lubricating oil of a part to the lubricated part of the internal combustion engine is disposed, and the decompression space is provided between a predetermined part of the oil storage part and another predetermined part. The above 1. To 3. The oil-diluted fuel separator according to any one of the above.

According to the oil-diluted fuel separation device of the present invention, the negative pressure generated in the negative pressure generating portion of the intake system is stored in the negative pressure tank, and the negative pressure stored in the negative pressure tank is supplied to the decompression space by the switching valve. The fuel component contained in the lubricating oil in the decompression space after the decompression space is decompressed is vaporized and separated by lowering its boiling point. As a result, the vaporization and separation of the fuel component in the lubricating oil is promoted, and the deterioration of the lubricating oil of the internal combustion engine can be suppressed by performing the vaporization and separation of the fuel component with less energy than conventional. In addition, the structure can be simplified as compared with the conventional structure in which the fuel component is vaporized and separated by a heater.
The communication path is connected to one end of a sub communication path connected to the negative pressure actuator, and the switching valve is disposed in the communication path and the communication section of the sub communication path, and When configured to switch supply / stop of the negative pressure stored in the pressure tank to the reduced pressure space and the negative pressure actuator, the negative pressure tank can also be used with the variable intake system, The structure can be further simplified.
Further, when one end of the blow-by gas passage is connected to the decompression space, the fuel component vaporized and separated in the decompression space can be sent to the intake pipe using the existing blow-by gas passage. Therefore, the structure of the entire apparatus can be further simplified, and remixing of the vaporized and separated fuel component into the lubricating oil can be more reliably prevented.
In addition, when one end side of the oil supply path is disposed in the decompression space or below the decompression space, the lubricating oil smoothly flows between the decompression space and the oil storage portion outside thereof. The lubricating oil after the vaporization and separation of the fuel component can be smoothly supplied to the lubricated portion of the internal combustion engine.
Furthermore, an oil guide part is further provided, and one end side of the oil supply path is disposed in another predetermined part spaced apart from the predetermined part of the oil storage part, and the predetermined part of the oil storage part and the other predetermined part When the decompression space is disposed between the oil storage portion, an oil flow is generated from the predetermined portion to the other predetermined portion via the decompression space in the oil storage portion. Therefore, it is possible to smoothly flow the lubricating oil between the decompression space and the outside oil storage portion, and to smoothly supply the lubricating oil after the vaporization separation of the fuel component to the lubricated portion of the internal combustion engine. it can.

1. In-oil diluted fuel separator This embodiment 1. The oil-diluted fuel separator according to 1 includes an oil storage part, a wall part, a communication path, a negative pressure tank, and a switching valve described below.

  As long as the “oil storage part” stores the lubricating oil of the internal combustion engine, the structure, size, shape, material, quantity, etc. are not particularly limited. Examples of the oil reservoir include an oil pan provided at the lower part of the main body of the internal combustion engine, an oil tank provided separately from the main body of the internal combustion engine, and the like.

The “wall” is not particularly limited in structure, size, shape, material, quantity, etc. as long as a decompression space including a part of the lubricating oil in the oil reservoir is formed in the crank chamber of the internal combustion engine. This wall part can be arrange | positioned, for example in the crank chamber of an internal combustion engine, and / or in an oil storage part.
The “depressurized space including a part of the lubricating oil” refers to a space partitioned in the crank chamber so as to include a part of the lubricating oil in the oil reservoir.

For example, one end side of a blow-by gas passage connected to an intake pipe constituting an intake system of an internal combustion engine can be connected to the decompression space. Examples of the blow-by gas passage include one or a combination of two or more of pipes, passages formed in the main body or mechanism of the internal combustion engine, and spaces.
In this case, for example, a flow rate control valve (also referred to as a “PCV valve”) is provided at one end side of the blow-by gas passage, and the branch side of the blow-by gas passage is branched into two or more from the flow rate control valve. The tip end side of at least one branch portion is connected to the decompression space, and the tip side of at least one other branch portion can be connected to the crank chamber (see FIG. 1). As a result, the structure can be further simplified, and the re-mixing of the fuel component into the lubricating oil can be more reliably prevented. It should be noted that the tip ends of the two or more branch portions are usually connected above the level of the lubricating oil in the reduced pressure space.

  The “connecting path” is not particularly limited in structure, size, shape, material, quantity, etc., as long as it communicates the decompression space and the negative pressure generating portion of the intake system of the internal combustion engine. Examples of the communication path include one or a combination of two or more of pipes, passages formed in the main body or mechanism of the internal combustion engine, and spaces. Examples of the negative pressure generating portion of the intake system of the internal combustion engine include an intake pipe, a surge tank, an air cleaner, and a blow-by gas passage.

  The “negative pressure tank” is not particularly limited in structure, size, shape, material, quantity, etc. as long as it stores the negative pressure provided in the communication path and generated in the negative pressure generating section. Between the negative pressure tank of the communication path and the connection end side to the negative pressure generating part, for example, supply of negative pressure from the negative pressure generating part to the negative pressure tank is allowed and negative pressure is generated from the negative pressure tank. There may be provided a check valve for restricting supply of negative pressure to the section.

  The “switching valve” is not particularly limited in its structure, size, shape, material, quantity, etc., as long as it switches supply / stop of the negative pressure stored in the negative pressure tank to the decompression space. Absent. This switching valve can be, for example, an electromagnetic valve that is switched and controlled by a control device. Moreover, this switching valve can be arrange | positioned, for example between the connection end side to the pressure reduction space of the said communication path, and a negative pressure tank.

  The switching valve includes, for example, the fuel dilution of the lubricating oil, pressure, temperature, viscosity, the temperature of the cooling water that cools the lubricating oil, the temperature of the part that constitutes the internal combustion engine, the operating state of the internal combustion engine (for example, the rotational speed, The control device can perform switching control based on one type or a combination of two or more types of timings such as the time when sub-injection such as pilot injection or post injection is performed. Thereby, the fuel component in lubricating oil can be vaporized and separated more efficiently.

Here, for example, one end side of a sub communication path connected to a negative pressure actuator that opens and closes a variable intake valve constituting a variable intake system of an internal combustion engine is connected to the communication path, and the switching valve is connected to the communication path. In addition to being disposed in the communication portion of the road and the sub-communication path, the supply / stop of the negative pressure stored in the negative pressure tank and the negative pressure actuator can be switched.
In this case, the switching valve does not supply the negative pressure of the negative pressure tank to the reduced pressure space when the rotational speed of the internal combustion engine is less than a predetermined set value (or higher than the predetermined set value), for example. And the negative pressure of the negative pressure tank is supplied to the decompression space and not to the negative pressure actuator when the rotational speed of the internal combustion engine is equal to or higher than a predetermined set value (or less than the predetermined set value). Can be.

  The “variable intake system” is intended to be a system that improves the intake efficiency by changing the number, length, diameter, etc. of the intake pipes according to the operating state such as the rotational speed of the internal combustion engine. In this variable intake system, for example, in a low rotation range of an internal combustion engine (for example, less than 5000 rpm), the negative pressure of the negative pressure tank is (or is not) applied to the negative pressure actuator, and the surge tank is connected with the variable intake valve. While closing and substantially increasing the length of the intake pipe (effective intake pipe length), the negative pressure of the negative pressure tank does not act on (or acts on) the actuator in the high rotation range (for example, 5000 rpm or more) of the internal combustion engine. The surge tank is opened with a variable intake valve so that the length of the intake pipe (effective intake pipe length) is substantially shortened. Therefore, the variable intake valve and negative pressure tank that make up the variable intake system are not always used. When these variable intake valve and negative pressure tank are not used, the negative pressure of the negative pressure tank is used. Thus, the decompression space can be decompressed.

  Here, the first embodiment. For example, (1) an oil supply passage for supplying the lubricating oil in the oil reservoir to the lubricated part of the internal combustion engine is provided in the decompressed space or below the decompressed space. A configuration in which one end side is disposed (see FIG. 1), and (2) an oil guide portion that guides lubricating oil that has lubricated the lubricated portion of the internal combustion engine to a predetermined portion of the oil storage portion, One end side of the oil supply path for supplying the lubricating oil of the oil storage part to the lubricated part is disposed in another predetermined part separated from the predetermined part, and the predetermined part of the oil storage part and the other predetermined part And the like (see FIG. 3) in which a decompression space is disposed.

  In the above (1) and (2) modes, examples of the oil supply path include one or a combination of two or more of pipes, passages formed in the body or mechanism of the internal combustion engine, spaces, and the like. Can do. Moreover, in the said (1) (2) form, the oil strainer can be provided in the one end side of the said oil supply path, for example. Furthermore, in the above (2) mode, for example, the predetermined portion may be one side wall side of the oil storage portion, and the other predetermined portion may be the opposite wall side facing the one side wall.

Examples of the “lubricated part of the internal combustion engine” include a crankshaft, a connecting rod, a piston, a camshaft, and a drive system. Of these, relatively large amount of fuel leaking from the gaps in the cylinder inner wall surface of the piston is mixed in the lubricating oil that circulates around the piston such as the crankshaft, the connecting rod, and the piston and is returned to the oil reservoir. . On the other hand, almost no fuel is mixed in the lubricating oil that circulates around the head such as the camshaft and the drive system and is returned to the oil reservoir. Further, the lubricating oil circulating around the piston is usually returned to the oil reservoir through a gap between the piston and the cylinder. On the other hand, the lubricating oil that circulates around the head is usually returned to the oil reservoir through a communication path that is formed in the cylinder block and cylinder head of the engine and connects the crank chamber and the space in the head cover. Or returned to the oil reservoir through the case or belt case.
Examples of the “internal combustion engine” include a gasoline engine, a diesel engine, a biofuel engine, and the like. Therefore, the first embodiment. Examples of the fuel separated by the oil-in-oil diluted fuel separator include gasoline, diesel fuel, biofuel, and the like.

  Hereinafter, the present invention will be specifically described with reference to the drawings. In this embodiment, as an “internal combustion engine” according to the present invention, an in-cylinder injection type engine (hereinafter, also simply referred to as “engine”) that performs sub-injection before and after main injection is illustrated.

Example 1
(1) Engine Configuration As shown in FIG. 1, the engine 1 according to the first embodiment includes a cylinder block 1a in which a cylinder 2 is formed, and a cylinder head 1b fixed to the upper portion of the cylinder block 1a. ing. A piston 3 is supported in the cylinder 2 of the cylinder block 1a so as to be able to reciprocate. In addition, a crankcase 1c configured to rotatably support the crankshaft 4 is fixed to the lower portion of the cylinder block 1a. The crankshaft 4 is connected to the piston 3 via a connecting rod 5. A combustion chamber 6 surrounded by the top surface of the piston 3, the wall surface of the cylinder head 1b, and the wall surface of the cylinder 2 is formed above the piston 3.

  One end side of the cylinder head 1b is connected to an intake pipe 7a (illustrated as an “intake system” according to the present invention), and the other end side is connected to the combustion chamber 6; An exhaust port 8b connected to the tube 7b and connected to the combustion chamber 6 at the other end is formed. The cylinder head 1b is provided with an intake valve 9a for opening and closing the intake port 8a and an exhaust valve 9b for opening and closing the exhaust port 8b, and camshafts 10a and 10b for driving the intake valve 9a and the exhaust valve 9b, respectively. It is supported rotatably. Further, a cylinder head cover 1d that covers the valve mechanism is attached to the upper portion of the cylinder head 1b. One end side of the intake pipe 7 a is connected to the air cleaner box 11. In the middle of the intake pipe 7a, a throttle valve 12 for adjusting the amount of intake air flowing through the intake pipe 7a is provided. Further, the space 13 in the cylinder head cover 1d is connected to the other end side of the reduction flow path 16 whose one end side is connected to the upstream side of the throttle valve 12 of the intake pipe 7a.

  The engine 1 is provided with a variable intake system 20 that improves the intake efficiency by changing the length of the intake pipe 7a according to the rotational speed. The variable intake system 20 includes a surge tank 21 formed on the downstream side of the throttle valve 12 of the intake pipe 7a. A variable intake valve 22 for opening and closing the inlet is provided in the vicinity of the inlet of the surge tank 21 of the intake pipe 7a. The variable intake valve 22 is opened and closed by a diaphragm type negative pressure actuator 23. The negative pressure stored in the negative pressure tank 34 is supplied to the negative pressure actuator 23. The variable intake system 20 is variable by causing the negative pressure of the negative pressure tank 34 to act on the negative pressure actuator 23 as shown in FIG. 2A in the low rotation range of the engine 1 (for example, less than 5000 rpm). The surge tank 21 is closed by the intake valve 22 to substantially increase the length of the intake pipe 7a (effective intake pipe length). On the other hand, in the high rotation range of the engine 1 (for example, 5000 rpm or more), as shown in FIG. 2B, the negative pressure in the negative pressure tank 34 is not applied to the negative pressure actuator 23 and the surge tank is operated by the variable intake valve 22. 21 is opened, and the length of the intake pipe 7a (effective intake pipe length) is substantially shortened.

(2) Configuration of In-Oil Diluted Fuel Separation Device As shown in FIG. 1, the in-oil diluted fuel separation device 30 according to the first embodiment is exemplified as an oil pan 31 (an “oil reservoir” according to the present invention). ), A wall portion 32, a communication path 33, a negative pressure tank 34, and a switching valve 35. The oil pan 31 and a portion to be lubricated (for example, a crankshaft, a connecting rod, a piston, a camshaft, a drive system, etc.) of the engine 1 are connected via an oil circulation path (not shown).

  The wall portion 32 is provided in the crank chamber 14 of the engine 1 in a box shape with the lower part opened. The wall portion 32 includes a side wall 31a of the oil pan 31, a ceiling wall 37a extending in the horizontal direction from the side wall 31a, and a side wall 37b extending downward from the outer peripheral edge of the ceiling wall 37a. The wall 32 forms a decompression space 38 that partitions the crank chamber 14 so as to include part of the oil in the oil pan 31. In addition, a communication path 39 is formed between the lower end side of the wall portion 32 and the bottom surface of the oil pan 31 for flowing oil between the decompression space 38 and the oil pan 31 outside the decompression space 38. .

  The decompression space 38 is connected to the other end of a blow-by gas passage 40 having one end connected to the downstream side of the throttle valve 12 of the intake pipe 7a. Specifically, a flow control valve 41 (also referred to as “PCV valve”) is provided on the other end side of the blow-by gas passage 40, and the front end side of the blow-by gas passage 40 is bifurcated from the flow control valve 41. The two branch portions 40a and 40b are branched into two. And the front end side of one branch part 40a is connected to the upper side rather than the liquid level of the oil of the decompression space 38. FIG. Further, the tip end side of the other branch portion 40 b is connected to the crank chamber 14.

  One end side of the communication path 33 is connected to the upstream side of the slot valve 12 (illustrated as the “negative pressure generating portion” according to the present invention), and the other end side is above the oil level of the decompression space 38. It is connected to the. The communication path 33 is provided with a check valve 44, a negative pressure tank 34, and a switching valve 35 (three-way switching valve). The check valve 44 allows negative pressure to be supplied from the negative pressure generation unit to the negative pressure tank 34 and restricts supply of negative pressure from the negative pressure tank 34 to the negative pressure generation unit. The negative pressure tank 34 is configured to store a predetermined amount of negative pressure generated by the negative pressure generator.

  One end of the switching valve 35 is connected to the other end of a sub-communication path 45 that communicates with the negative pressure actuator 23. The switching valve 35 does not supply the negative pressure of the negative pressure tank 34 to the decompression space 38 when the rotational speed of the engine 1 is less than a predetermined set value (for example, less than 5000 rpm) under the control of the control device 46. While supplying to the negative pressure actuator 23, the negative pressure of the negative pressure tank 34 is supplied to the decompression space 38 and to the negative pressure actuator 23 when the rotational speed of the engine 1 is not less than a predetermined set value (for example, 5000 rpm or more). It is configured not to supply.

  Below the decompression space 38, an oil strainer 48 provided on one end side of an oil supply passage 47 for supplying the oil in the oil pan 31 to the lubricated portion of the engine 1 is disposed. An oil pump 49 that is operated by the driving force of the engine 1 is provided in the middle of the oil supply path 47. When the oil in the decompression space 38 is sucked by the oil strainer 48 by the operation of the oil pump 49, an oil flow F is generated from the outside of the decompression space 38 toward the decompression space 38.

(3) Operation of the oil-diluted fuel separator 30 Next, the operation of the oil-diluted fuel separator 30 configured as described above will be described.
In the low rotation range of the engine 1 (for example, less than 5000 rpm), the negative pressure in the negative pressure tank 34 is supplied to the negative pressure actuator 23 by the switching valve 35. Then, the surge tank 21 is closed by the variable intake valve 22 by the operation of the negative pressure actuator 23, the length of the intake pipe 7a (effective intake pipe length) is substantially increased, and the intake efficiency in the low rotation range is improved. On the other hand, the negative pressure in the negative pressure tank 34 is not supplied to the negative pressure actuator 23 by the switching valve 35 in the high rotation range of the engine 1 (for example, 5000 rpm or more). Then, the surge tank 21 is opened by the variable intake valve 22, and the length of the intake pipe 7a (effective intake pipe length) is substantially shortened to improve the intake efficiency in the high rotation range.

Further, in the high rotation range of the engine 1 (for example, 5000 rpm or more), the negative pressure in the negative pressure tank 34 is supplied to the decompression space 38 by the switching valve 35. Then, the inside of the decompression space 38 is decompressed, and the fuel component contained in the oil in the decompression space 38 is vaporized and separated with its boiling point lowered. The vaporized and separated fuel component is sent to the intake pipe 7a through the blow-by gas passage 40. Further, blow-by gas generated in the crank chamber 14 is also sent to the intake pipe 7a via the blow-by gas passage 40, and blow-by gas in the cylinder head cover 1d is sent to the intake pipe 7a via the reduction flow path 16. Further, the oil after the fuel component is vaporized and separated in the decompression space 38 is sucked from the oil strainer 48 by the operation of the oil pump 49 and supplied to the lubricated portion of the engine 1 through the oil supply path 47. Further, the oil outside the decompression space 38 of the oil pan 31 flows into the decompression space 38 by the oil flow F.
In the low rotation region of the engine 1, fresh air flowing upstream of the throttle valve 12 of the intake pipe 7a is drawn into the space 13 in the cylinder head cover 1d via the reduction flow path 16, and blow-by gas in the space 13 is It will be ventilated.

(4) Effects of Embodiment 1 As described above, in the oil-diluted fuel separator 30 of Embodiment 1, the wall portion 32 that forms the decompression space 38 is provided in the crank chamber 14, and the decompression space 38 and the intake pipe 7a are provided. Since the negative pressure tank 34 and the switching valve 35 are provided in the communication path 33 that communicates with each other, the negative pressure generated in the intake pipe 7a is stored in the negative pressure tank 34, and is stored in the negative pressure tank 34 by the switching valve 35. The negative pressure is supplied to the decompression space 38, the inside of the decompression space 38 is decompressed, and the fuel component contained in the oil in the decompression space 38 is vaporized and separated with its boiling point lowered. As a result, the vaporization and separation of the fuel component in the lubricating oil is promoted, and the deterioration of the lubricating oil of the internal combustion engine can be suppressed by performing the vaporization and separation of the fuel component with less energy than conventional. In addition, the structure can be simplified as compared with the conventional structure in which the fuel component is vaporized and separated by a heater.

  In the first embodiment, the switching valve 35 is connected to one end side of the sub communication path 45 connected to the negative pressure actuator 23 constituting the variable intake system 20, and is stored in the negative pressure tank 34 by the switching valve 35. Since the negative pressure reducing space 38 and the supply / stop of the negative pressure actuator 23 are switched, the negative pressure tank 23 can be shared with the variable intake system 20, and the structure of the entire apparatus is simplified. Can be

  Further, in the first embodiment, since one end side of the blow-by gas passage 40 is connected to the decompression space 38, the fuel component vaporized and separated in the decompression space 38 is supplied to the intake pipe 7a using the existing blow-by gas passage 40. Can send. Therefore, the structure of the entire apparatus can be further simplified, and remixing of the vaporized and separated fuel component into the lubricating oil can be more reliably prevented.

  Further, in the first embodiment, since the oil strainer 48 on one end side of the oil supply path 47 is disposed in the decompression space 38 or on the lower side of the decompression space 38, the inside of the decompression space 38 and the oil pan 31 outside thereof. The lubricating oil can be smoothly flowed in between and the lubricating oil after the vaporization and separation of the fuel component can be smoothly supplied to the lubricated portion of the engine 1.

(Example 2)
Next, the in-oil diluted fuel separator 50 according to the second embodiment will be described. Note that in the oil-in-diluted fuel separator 50 according to the second embodiment, the same components as those in the oil-diluted fuel separator 30 in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

(1) Configuration of Oil-Dilute Fuel Separation Device In the oil-diluted fuel separation device 50 according to the second embodiment, as shown in FIG. A plate-like oil guide 52 is provided to guide to the 51a side (illustrated as “a predetermined portion of the oil reservoir” according to the present invention). Further, the oil in the oil pan 51 is supplied to the side of the opposing wall 51b facing the side wall 51a of the oil pan 51 (illustrated as “another predetermined portion of the oil storage portion” according to the present invention). An oil strainer 54 on one end side of the oil supply path 53 for supplying to the lubricated part is disposed.

  Further, in the crank chamber 14, a box-shaped wall portion 55 is provided at a substantially intermediate portion between the side wall 51 a of the oil pan 51 and the opposing wall 51 b. The wall portion 55 includes a ceiling wall 55a extending in the horizontal direction and a side wall 55b extending downward from the outer peripheral edge of the ceiling wall 55a. The wall 55 forms a decompression space 56 that partitions the crank chamber 14 so as to include part of the oil in the oil pan 51. In addition, a communication path 57 is formed between the lower end side of the wall 55 and the bottom surface of the oil pan 51 to allow oil to flow between the decompression space 56 and the oil pan 51 outside. .

(2) Operation of the oil-in-diluted fuel separator Next, the operation of the oil-in-diluted fuel separator 50 having the above-described configuration will be described. In the second embodiment, the oil guide portion 52 is provided, and the decompression space 56 and the oil strainer 54 are in the above-described specific arrangement relationship so that the oil pan 51 is opposed to the side wall 51a via the decompression space 56. An oil flow F ′ directed toward the wall 51b is generated.

  The oil that has lubricated the lubricated part of the engine 1 is guided to the side wall 51a side of the oil pan 51 by the oil guide part 52, and flows into the decompression space 56 by the oil flow F '. In the high rotation range of the engine 1 (for example, 5000 rpm or higher), the negative pressure in the negative pressure tank 34 is supplied to the decompression space 56 by the switching valve 35. Then, the inside of the decompression space 56 is decompressed, and the fuel component contained in the oil in the decompression space 56 is vaporized and separated with its boiling point lowered. The vaporized and separated fuel component is sent to the intake pipe 7a through the blow-by gas passage 40. Further, the oil after the fuel components are vaporized and separated in the decompression space 56 flows to the opposite wall 51b side of the oil pan 51 by the oil flow F ′, and is sucked from the oil strainer 54 by the operation of the oil pump 49 to supply the oil. It will be supplied to the lubricated part of the engine 1 via the path 53.

(3) Effects of Embodiment 2 As described above, the oil-in-diluted fuel separator 50 according to the second embodiment has substantially the same operations and effects as those of the oil-in-diluted fuel separator 30 according to the first embodiment. The oil pan 51 further includes an oil guide portion 52 for guiding the oil after lubrication on the side wall 51a side, and an oil strainer 54 on one end side of the oil supply path 53 on the opposite wall 51b side spaced from the side wall 51a side of the oil pan 51. Since the decompression space 56 is disposed at a substantially intermediate portion between the side wall 51a side and the opposing wall 51b side of the oil pan 51, the opposing wall 51b from the side wall 51a side through the decompression space 56 in the oil pan 51 is disposed. An oil flow F ′ toward the side is generated. Therefore, the oil can smoothly flow between the decompression space 56 and the oil pan 51 outside thereof, and the oil after the vaporization separation of the fuel component can be smoothly supplied to the lubricated portion of the engine 1. it can.

  In the present invention, the present invention is not limited to the first and second embodiments, and various modifications can be made within the scope of the present invention depending on the purpose and application. That is, in the first and second embodiments, the decompression spaces 38 and 56 are decompressed using the negative pressure tank 34 constituting the variable intake system 20, but the present invention is not limited to this. For example, the negative pressure tank 34 Alternatively, a negative pressure tank dedicated to decompression may be provided, and the decompression space may be decompressed by the negative pressure stored in the negative pressure tank. In this case, the engine 1 may include the variable intake system 20 or may not include the variable intake system 20.

  Further, in the first and second embodiments, one end side of the blow-by gas passage 40 is connected to the decompression spaces 38 and 56, and the fuel component vaporized and separated in the decompression spaces 38 and 56 is taken into the intake pipe via the blow-by gas passage 40. However, the present invention is not limited to this. For example, the decompression spaces 38 and 56 are provided with openings in the crank chamber 14 that are opened and closed by the valve body, and the decompression spaces 38 and 56 are opened through the openings. The fuel component vaporized and separated in step 1 is once exhausted into the crank chamber 14, and the fuel component after vaporization and separation is connected to the blow-by gas passage 40 (or the internal space of the cylinder head cover and the intake pipe) together with the blow-by gas in the crank chamber 14. It may be sent to the intake pipe 7a via a blow-by gas passage.

  It is widely used as a technique for separating fuel components mixed in lubricating oil of an internal combustion engine. In particular, it is suitably used as a technique for separating a fuel component from oil used in an engine of a system in which the fuel component is likely to be mixed into oil such as a direct injection engine.

1 is a longitudinal sectional view of an engine including an in-oil diluted fuel separator according to a first embodiment. It is a schematic diagram for demonstrating the change of the effective intake pipe length of an intake pipe, (a) shows the state where the effective intake pipe length of an intake pipe is long, (b) shows the state where the effective intake pipe length of an intake pipe is short. It is a principal part longitudinal cross-sectional view of an engine provided with the oil dilution fuel separation apparatus which concerns on the present Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Engine, 14; Crank chamber, 20; Variable intake system, 22; Variable intake valve, 23; Negative pressure actuator, 30, 50; Diluted fuel separator in oil, 31, 51; Oil pan, 32, 55; 34, negative pressure tank, 35; switching valve, 38, 56; decompression space, 40; blow-by gas passage, 45; sub-communication passage, 46; control device, 47, 53;

Claims (5)

An oil reservoir for storing lubricating oil of the internal combustion engine;
A wall portion forming a decompression space including a part of the lubricating oil of the oil reservoir in the crank chamber of the internal combustion engine;
A communication path that connects the decompression space and the negative pressure generating portion of the intake system of the internal combustion engine;
A negative pressure tank that is provided in the communication path and stores negative pressure generated in the negative pressure generating section;
And a switching valve for switching supply / stop of the negative pressure stored in the negative pressure tank to the decompression space, provided in the communication path.   One end side of a sub communication path connected to a negative pressure actuator that opens and closes a variable intake valve that constitutes a variable intake system of the internal combustion engine is connected to the communication path, and the switching valve includes the communication path and the sub communication path. 2. The oil according to claim 1, wherein the oil is disposed in a communication portion of the road and is configured to switch supply / stop of the negative pressure stored in the negative pressure tank to the reduced pressure space and the negative pressure actuator. Medium dilution fuel separator.   3. The diluted oil-in-oil separator according to claim 1, wherein one end side of a blow-by gas passage connected to an intake pipe constituting an intake system of the internal combustion engine is connected to the decompression space.   The one end side of the oil supply path for supplying the lubricating oil of the said oil storage part to the to-be-lubricated part of the said internal combustion engine is arrange | positioned in the said decompression space or the downward side of the said decompression space. The oil-diluted fuel separator according to any one of the above.   The oil guide further includes an oil guide that guides lubricated oil that has lubricated the lubricated portion of the internal combustion engine to a predetermined portion of the oil reservoir, and the oil reservoir is provided in another predetermined portion that is separated from the predetermined portion of the oil reservoir. One end side of an oil supply path for supplying lubricating oil of a part to the lubricated part of the internal combustion engine is disposed, and the decompression space is provided between a predetermined part of the oil storage part and another predetermined part. The in-oil diluted fuel separator according to any one of claims 1 to 3, wherein the apparatus is a fuel-in-oil diluted fuel separator.

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