JP2010084742A - Fuel separating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel separating device inhibiting the unbalance of air-fuel ratio by reducing fuel concentration in blow-by gas containing fuel components evaporated and separated from lubricating oil. <P>SOLUTION: This device 1 includes: a blow-by gas circulation means (blow-by gas circulation part 21) circulating blow-by gas formed in an internal combustion engine to an intake system; a bypass passage 29 disposed at a blow-by gas passage 23 constructing the blow-by gas circulation means, bypassing part 23a of the blow-by gas passage; a collecting means (filter 30) disposed in the bypass passage and collecting the fuel component contained in the bypass passage; and passage change over means (solenoid valve 34 and ECU 41) opening one of the bypass passage and the part of the blow-by gass passage based on concentration of fuel component contained in the blow-by gas. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel separation device, and more particularly, to a fuel separation device that can reduce a fuel concentration in a blow-by gas containing a fuel component vaporized and separated from lubricating oil to suppress an air-fuel ratio imbalance. .

2. Description of the Related Art Conventionally, in an engine such as an automobile, it is generally known to provide blow-by gas recirculation means for recirculating blow-by gas leaking from a combustion chamber to a crank chamber to an intake system to prevent release into the atmosphere (for example, , See Patent Document 1).
In Patent Document 1, the flow rate of the PCV valve is adjusted during idling or low load, which tends to affect the air-fuel ratio (A / F), thereby adjusting the flow of blow-by gas containing excessive fuel components into the intake system. Is disclosed.

JP 2006-52664 A

  Here, among automobile drivers, there is a short-distance driver mainly using a short trip that repeatedly starts and stops the engine before the engine oil warms up. However, since the flow rate of the PCV valve is adjusted only during idling or light load in the above-mentioned Patent Document 1, in the case of the short distance driver described above, the frequency of the PCV valve being throttled is increased, and the cylinder head cover is increased. The fuel concentration inside continues to rise. At this time, if the high-load operation is suddenly performed, the air-fuel ratio may be out of balance even during idling, which may cause abnormal combustion such as knocking.

  The present invention has been made in view of the above-described situation, and provides a fuel separation device that can reduce the fuel concentration in the blowby gas containing the fuel component vaporized and separated from the lubricating oil and suppress the collapse of the air-fuel ratio. The purpose is to provide.

The present invention is as follows.
1. Blow-by gas recirculation means for recirculating blow-by gas generated in the internal combustion engine to the intake system;
A bypass passage provided around the blowby gas passage in the blowby gas passage constituting the blowby gas recirculation means;
A collecting means for collecting a fuel component provided in the blow-by gas provided in the bypass passage and flowing through the bypass passage;
A fuel separation device comprising: a passage switching means for conducting one of the bypass passage and a part of the blowby gas passage based on the concentration of the fuel component contained in the blowby gas. .
2. 1. The fuel cell according to the above 1., further comprising a detaching unit that detaches the fuel component collected by the collecting unit from the collecting unit and returns the fuel component to the crank chamber of the internal combustion engine. The fuel separator described.
3. The detaching means is included in the blow-by gas, a communication path that connects the upstream side of the collection means of the bypass passage and the crank chamber of the internal combustion engine, an electromagnetic valve for opening and closing the communication path, and And 1. a control device that controls the operation of the solenoid valve based on the concentration of the fuel component. Or 2. The fuel separator described in 1.
4). The passage switching means controls the operation of the solenoid valve based on a concentration of a fuel component contained in the blow-by gas, and a solenoid valve that conducts one of the bypass passage and a part of the blow-by gas passage. And 1. a control device that performs the above. To 3. The fuel separator according to any one of the above.
5). The blow-by gas passage is a passage connecting the crank chamber of the internal combustion engine and the intake system. To 4. The fuel separator according to any one of the above.
6). The blow-by gas passage is a passage connecting the internal space of a cylinder head cover of the internal combustion engine and the intake system. To 4. The fuel separator according to any one of the above.

According to the fuel separator of the present invention, blow-by gas generated in the internal combustion engine is recirculated to the intake system via the blow-by gas passage by the blow-by gas recirculation means, and the fuel component contained in the blow-by gas is recirculated by the passage switching means. Based on the concentration, one of the bypass passage having the collecting means and a part of the blow-by gas passage bypassed by the bypass passage is conducted. Thereby, when the density | concentration of the fuel component in blow-by gas is high, a bypass channel is made into conduction and the fuel component contained in blow-by gas which flows through a bypass channel by a collection means is collected. Therefore, the fuel concentration in the blow-by gas containing the fuel component vaporized and separated from the lubricating oil can be reduced, and the collapse of the air-fuel ratio can be suppressed. Moreover, useless pressure loss in the blow-by gas passage can be suppressed.
Further, in the case of further comprising a detaching means for detaching the fuel component collected by the collecting means from the collecting means and returning it to the crank chamber of the internal combustion engine, the fuel component collected by the collecting means is cranked. It can be automatically returned to the room, and maintainability can be improved.
Further, the detaching means includes a communication path connecting the upstream side of the collecting means of the bypass passage and the crank chamber of the internal combustion engine, an electromagnetic valve for opening and closing the communication path, and the blow-by gas. And a control device that controls the operation of the solenoid valve based on the concentration of the contained fuel component, in a state where the concentration of the fuel component in the blow-by gas is low and the bypass passage is non-conductive, that is, the collecting means In the unused state, the fuel component collected by the collecting means via the communication path can be easily and reliably detached from the collecting means and returned to the crank chamber.
Further, the passage switching means is configured to connect an electromagnetic valve that conducts one of the bypass passage and a part of the blow-by gas passage, and the electromagnetic valve based on the concentration of the fuel component contained in the blow-by gas. And a control device that controls the operation, the bypass passage can be more reliably conducted when the concentration of the fuel component in the blow-by gas is high.
When the blow-by gas passage is a passage connecting the crank chamber of the internal combustion engine and the intake system, the collecting means can be installed in the vicinity of the crank chamber. Thereby, when returning the fuel component collected by the collection means into the crank chamber, the return passage can be made relatively short.
Further, when the blow-by gas passage is a passage connecting the internal space of the cylinder head cover of the internal combustion engine and the intake system, the bypass passage and the collection are made using a relatively wide space upstream of the cylinder head cover. Means can be easily installed.

  Embodiment 1 The fuel separation device according to the present invention includes a blow-by gas recirculation means, a bypass passage, a collection means, and a passage switching means described below. This fuel separation device can further include, for example, a detachment means described later.

  The “blowby gas recirculation means” is not particularly limited in its structure, recirculation form, installation form, size, shape, material, quantity, etc., as long as the blowby gas generated in the internal combustion engine is recirculated to the intake system. This blow-by gas recirculation means has one or more blow-by gas passages.

Examples of the blowby gas passage include (1) a passage connecting the crank chamber of the internal combustion engine and the intake system, (2) a passage connecting the internal space of the cylinder head cover of the internal combustion engine and the intake system, and (3) the internal combustion engine. One or a combination of two or more of a passage connecting the crank chamber of the engine and the internal space of the cylinder head cover, and (4) the internal space of the cylinder head cover can be given.
In the embodiments (1) to (4), examples of the blow-by gas passage include one type or a combination of two or more types of piping, a passage formed in a main body or mechanism of an internal combustion engine, a space, and the like. be able to.
In the above configurations (1) and (2), the blow-by gas passage usually has a flow rate adjustment valve (also referred to as a “PCV valve”) that can adjust the flow rate of gas sent to the intake pipe. The intake system can be, for example, downstream of the throttle valve of the intake pipe.

  The “bypass passage” is not particularly limited in its structure, installation form, size, shape, material, quantity, etc. as long as it is provided in the blow-by gas passage so as to bypass a part of this passage. Examples of the bypass passage include one or a combination of two or more of piping, a passage formed in a main body or a mechanism portion of the internal combustion engine, a space, and the like.

  As long as the “collecting means” collects the fuel component contained in the blow-by gas provided in the bypass passage and flowing through the bypass passage, the structure, the collection form, the installation form, the size, the shape, the material, The quantity is not particularly limited. This collection means can be means for collecting, for example, a fuel component and an oil component (mainly oil mist) contained in blow-by gas flowing through the bypass passage. Thereby, useless loss | disappearance of lubricating oil can be suppressed.

Examples of the collecting means include (1) a filter having a filter medium that filters the blow-by gas to collect the fuel component contained in the blow-by gas, and (2) adsorbs the fuel component contained in the blow-by gas. A canister having an adsorbent to be collected can be used.
In the above (1) form, the filter medium may be formed from a nonwoven fabric, a woven fabric, paper, or the like, but the filter medium is a rubber-like polymer separation membrane (particularly, a rubber-like polymer hollow fiber membrane). preferable. This is because the fuel component in the blow-by gas can be collected more efficiently.
In the form (2), examples of the adsorbent include activated carbon, activated carbon fiber, molecular sieve carbon, silica gel, activated alumina, and zeolite.

  The above-mentioned “passage switching means” is structured, switched, and installed as long as one of the bypass passage and part of the blowby gas passage is conducted based on the concentration of the fuel component contained in the blowby gas. The form, size, shape, material, quantity, etc. are not particularly limited.

The passage switching means controls the operation of the solenoid valve based on, for example, an electromagnetic valve that conducts one of the bypass passage and a part of the blow-by gas passage, and the concentration of the fuel component contained in the blow-by gas. And a control device.
The solenoid valve can be disposed, for example, in a communication part on the upstream side of a part of the bypass passage and the blow-by gas passage.
The control device, for example, in addition to or instead of the concentration of the fuel component contained in the blow-by gas, the fuel concentration, pressure, temperature, viscosity of the lubricating oil, the temperature of the cooling water for cooling the lubricating oil, the internal combustion engine The electromagnetic wave based on one or a combination of two or more of the temperature of the constituent parts and the operating state of the internal combustion engine (for example, the time when the sub-injection such as the rotational speed, pilot injection or post injection is performed). The valve can be controlled.
Examples of the fuel concentration acquisition mode include (a) a mode in which the dilution of the fuel component in the blow-by gas is detected by the fuel dilution sensor and the fuel concentration is acquired from the detected value, and (b) the blow-by gas by the oxygen sensor. The form etc. which detect the oxygen concentration in the inside and acquire fuel concentration from the detected value can be mentioned.

  As long as the “detaching means” is configured to remove the fuel component collected by the collecting means from the collecting means and return it to the crank chamber of the internal combustion engine, its structure, disengagement form, installation form, size, shape, material The quantity is not particularly limited.

  The separation means includes, for example, a communication path that connects the upstream side of the collection means of the bypass passage and the crank chamber of the internal combustion engine, an electromagnetic valve that opens and closes the communication path, and fuel contained in blow-by gas. And a control device that controls the operation of the solenoid valve based on the concentration of the component. As a result, the fuel component can be easily and reliably separated from the collecting means (particularly, the filter having the form (1)).

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, spaces, and the like.
For example, the electromagnetic valve may be disposed in a communication portion between the communication path and the bypass path.
The control device, for example, in addition to or instead of the concentration of the fuel component contained in the blow-by gas, the fuel concentration, pressure, temperature, viscosity of the lubricating oil, the temperature of the cooling water for cooling the lubricating oil, the internal combustion engine The electromagnetic wave based on one or a combination of two or more of the temperature of the constituent parts and the operating state of the internal combustion engine (for example, the time when the sub-injection such as the rotational speed, pilot injection or post injection is performed). The valve can be controlled.
In addition, as a form of acquiring the fuel concentration, for example, the form described in the above-described passage switching unit can be applied.

For example, (1) a mode in which a negative pressure is applied to the communication path to suck and desorb the fuel component from the collection unit; and (2) the collection unit. Or a combination of two or more of (3) a mode in which the fuel component is spontaneously released from the collecting means by the weight of the fuel component.
In the mode (1), for example, a negative pressure generated by a negative pressure generating source such as a pump or a blower is applied to the communication path, or a negative pressure generated in an intake system of an internal combustion engine is applied to the communication path. You can make it.

  Examples of the “internal combustion engine” include a gasoline engine, a diesel engine, and a biofuel engine. Therefore, the first embodiment. Examples of the fuel separated by the fuel separation device according to the above 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.

(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.

  An oil pan 15 for storing lubricating oil is attached to the lower portion of the cylinder block 1a. The oil pan 15 and a portion to be lubricated of the engine 1 (for example, a crankshaft, a connecting rod, a piston, a camshaft, a drive system, etc.) are connected via an oil circulation path including an oil supply path 16. An oil strainer 17 on one end side of the oil supply passage 16 for supplying the oil in the oil pan 15 to the lubricated portion of the engine 1 is disposed at a substantially central portion in the oil pan 15. An oil pump 18 that is operated by the driving force of the engine 1 is disposed in the middle of the oil supply path 16.

(2) Configuration of Fuel Separation Device The fuel separation device 20 according to the present embodiment has a blow-by gas recirculation unit 21 that recirculates blow-by gas leaking from the gap between the cylinder 2 and the piston 3 to the crank chamber 14 to the intake pipe 7a (present invention). This is exemplified as “blowby gas recirculation means”. The blow-by gas recirculation part 21 has a blow-by gas passage 23, a first connection path 24, and a second connection path 25.

  The blow-by gas passage 23 communicates the inside of the crank chamber 14 of the engine 1 and the downstream side of the throttle valve 12 of the intake pipe 7a. A known flow rate adjusting valve 26 (also referred to as a “PCV valve”) for adjusting the flow rate of blow-by gas sent to the intake pipe 7a is provided at the end of the blow-by gas passage 23 connected to the crank chamber 24. Is provided. The first communication path 24 communicates the internal space 13 of the cylinder head cover 1d with the upstream side of the throttle valve 12 of the intake pipe 7a. Further, the second communication path 25 is formed through the cylinder block 1a and the cylinder head 1b in the vertical direction, and connects the inside of the crank chamber 14 and the internal space 13 of the cylinder head cover 1d.

  The blow-by gas passage 23 is provided with a bypass passage 29 so as to bypass a part 23a thereof. As shown in FIG. 2A, the bypass passage 29 is provided with a filter 30 (illustrated as “collecting means” according to the present invention) that separates the fuel component and the oil component in the blow-by gas. ing. The filter 30 includes a cylindrical main body 31 and a silicon rubber hollow fiber membrane 32 (filter medium) accommodated in the main body 31. The hollow fiber membrane 32 is formed in a straw shape with one end closed. The hollow fiber membrane 32 divides the inside of the main body 31 into a dusty space 31a inside the hollow fiber membrane 32 and a clean space 31b outside the hollow fiber membrane 32, and the fuel in the blow-by gas in the dusty space 31a. Components and oil components are collected. In addition, a three-way electromagnetic valve 34 that is controlled by an ECU, which will be described later, is disposed in a communication portion on the upstream side of the bypass passage 29 and a part 23 a of the blow-by gas passage 23. Further, a check valve 35 for preventing a backflow of blow-by gas flowing through the bypass passage 29 toward the intake pipe 7a is disposed on the downstream side of the filter 30 in the bypass passage 29.

  The upstream side of the filter 30 in the bypass passage 29 and the inside of the crank chamber 14 are connected by a communication path 37. A three-way solenoid valve 38 that is controlled by an ECU, which will be described later, is disposed at a communication portion between the communication path 37 and the bypass path 29. In addition, the communication path 37 is provided with a pump 39 (see FIG. 1) for applying a negative pressure in the communication path 37 to suck and remove the fuel component from the filter 30. The pump 39 is operated by transmitting the driving force of the engine 1 at a predetermined timing by an ECU described later.

  In the cylinder head cover 1d, as shown in FIG. 1, a fuel dilution sensor 40 for detecting the dilution of the fuel component contained in the blowby gas is provided. The fuel dilution sensor 40 is electrically connected to an ECU 41 (illustrated as a “control device” according to the present invention) that controls various actuators of the engine 1. Based on the detection result from the fuel dilution sensor 40, the ECU 41 determines whether the bypass passage 29 and the blow-by gas passage 23 have a concentration when the concentration of the fuel component in the blow-by gas is a predetermined set value (for example, 5 vol%) or more. The electromagnetic valve 34 is controlled to operate so that the bypass passage 29 of the portion 23a is conducted, and the electromagnetic valve 38 is controlled to close the communication path 37. Further, the ECU 41 determines that the bypass passage 29 and the blow-by gas passage when the concentration of the fuel component in the blow-by gas is less than a predetermined set value (for example, 5 vol%) based on the detection result from the fuel dilution sensor 40. The operation of the solenoid valve 34 is controlled so that the part 23a of the blow-by gas passage 23 of the part 23a of the part 23 is conducted, the operation of the solenoid valve 38 is controlled so as to open the communication path 37, and the pump 39 is actuated.

  Here, the above-mentioned electromagnetic valve 34 and ECU 41 according to the present embodiment constitute a “passage switching means” according to the present invention. In addition, the communication path 37, the electromagnetic valve 38, and the ECU 41 according to the present embodiment constitute the “detaching means” according to the present invention.

(3) Operation of Fuel Separation Device Next, the operation of the fuel separation device 20 configured as described above will be described.
During the operation of the engine 1, the oil in the oil pan 15 is pumped to the lubricated portion of the engine 1 through the oil supply path 16 through the oil strainer 17 by the operation of the oil pump 18 and returned to the oil pan 15. It is. The fuel component contained in the oil in the oil pan 15 is vaporized and separated as the oil temperature rises, and is mixed into the blow-by gas generated in the crank chamber 14. This blow-by gas is sent from the crank chamber 14 to the internal space 13 of the cylinder head cover 1d through the second communication path 25, and is blow-by when the engine 1 is in a low load operation state (an operation state in which the throttle valve 12 is small). While being recirculated to the intake pipe 7a through the gas passage 23, when the engine 1 is in a high load operation state (an operation state in which the throttle valve 12 is open), in addition to the blow-by gas passage 23, the first connection passage 24 is used. It is recirculated to the intake pipe 7a.
When the engine 1 is in a low load operation state, fresh air flowing upstream of the throttle valve 12 of the intake pipe 7a through the first communication path 24 is sucked into the internal space 13 of the cylinder head cover 1d, and the blow-by in the space 13 is blown. Gas is ventilated.

  Here, during the operation of the engine 1, the fuel dilution sensor 40 detects the dilution of the fuel component contained in the blow-by gas flowing in the internal space 13 of the cylinder head cover 1d, and the detection result is input to the ECU 41. Then, the ECU 41 controls the operation of the three-way solenoid valves 34 and 38 when the concentration of the fuel component is equal to or higher than a predetermined set value (for example, 5 vol%) based on the detection result of the fuel dilution sensor 40 to bypass The bypass passage 29 of the passage 29 and the part 23a of the blow-by gas passage 23 is made conductive, and the communication passage 37 is closed {see FIG. 2 (a)}. Then, blowby gas having a relatively high concentration of fuel component flows through the bypass passage 29, and the fuel component and oil component in the blowby gas are collected by the filter 30. The blow-by gas from which the fuel component and the oil component are separated is sent to the intake pipe 7 a via the blow-by gas passage 23.

  On the other hand, the ECU 41 controls the operation of the three-way solenoid valves 34 and 38 when the concentration of the fuel component is less than a predetermined set value (for example, 5 vol%) based on the detection result of the fuel dilution sensor 40 to bypass Of the passage 29 and the portion 23a of the blow-by gas passage 23, the portion 23a of the blow-by gas passage 23 is brought into conduction and the communication passage 37 is opened {see FIG. 2 (b)}. Further, the ECU 41 operates the pump 39 to apply a negative pressure to the communication path 37 and the filter 30. Then, a blow-by gas having a relatively low concentration of the fuel component flows through the blow-by gas passage 23, and the blow-by gas is sent to the intake pipe 7a. Further, the fuel component and the oil component collected by the filter 30 are sucked and separated by the action of negative pressure and returned to the crank chamber 14 through the communication path 37.

(4) Effects of the Embodiment As described above, in the fuel separation device 20 of the present embodiment, the blow-by gas passage 23 is provided with the bypass passage 29 having the filter 30 that collects the fuel component contained in the blow-by gas. Since the bypass passage 29 is made conductive / non-conductive based on the concentration of the fuel component therein, the bypass passage 29 is made conductive when the concentration of the fuel component in the blowby gas is high, and flows through the bypass passage 29 by the filter 30. The fuel component in blow-by gas can be collected. As a result, the fuel concentration in the blow-by gas containing the fuel component vaporized and separated from the lubricating oil can be reduced and the collapse of the air-fuel ratio can be suppressed. Moreover, useless pressure loss in the blow-by gas passage 23 can be suppressed.

  Further, in this embodiment, the fuel component collected by the filter 30 is separated from the filter 30 and returned to the crank chamber 14 of the engine 1. Can increase the sex.

  In the present embodiment, the upstream side of the filter 30 in the bypass passage 29 and the inside of the crank chamber 14 of the engine 1 are connected by a communication path 37, and an electromagnetic valve 38 for opening and closing the communication path 37 is provided. Since the ECU 41 for controlling the operation of the solenoid valve 38 based on the concentration of the fuel component therein is provided, the concentration of the fuel component in the blowby gas is low and no blowby gas is flowing through the bypass passage 29, that is, the filter 30 is not used. In this state, the fuel component collected by the filter 30 can be easily and reliably separated from the filter 30 and returned to the crank chamber 14.

  In the present embodiment, the pump 39 that is controlled by the ECU 41 and applies a negative pressure to the communication path 37 is provided, so that the fuel component collected by the filter 30 can be sucked and separated, and the fuel component can be removed. It can be returned to the crank chamber 14 more reliably.

  In the present embodiment, the electromagnetic valve 34 for connecting / disconnecting the bypass passage 29 is provided, and the ECU 41 for controlling the operation of the electromagnetic valve 34 based on the concentration of the fuel component in the blow-by gas is provided. When the concentration of the fuel component is high, the bypass passage 29 can be more reliably conducted.

  Further, in the present embodiment, the bypass passage 29 having the filter 30 is provided in the blow-by gas passage 23 that communicates the inside of the crank chamber 14 of the engine 1 and the intake pipe 7 a, so that the filter 30 is installed in the vicinity of the crank chamber 14. The return path (communication path 37) for the fuel component collected by the filter 30 can be made relatively short.

  Furthermore, in this embodiment, the filter 30 having the hollow fiber membrane 32 made of rubber-like polymer such as silicon rubber that collects the fuel component and oil component in the blow-by gas is employed. Separation can be performed efficiently and wasteful disappearance of oil can be suppressed.

  In the present invention, the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention depending on the purpose and application. That is, in the above-described embodiment, the bypass passage 29 having the filter 30 is provided in the blow-by gas passage 23 that communicates the inside of the crank chamber 14 of the engine 1 and the intake pipe 7a. As shown in FIG. 3, a bypass passage 29 having a filter 30 may be provided in the blow-by gas passage 43 that connects the internal space 13 of the cylinder head cover 1d of the engine 1 and the intake pipe 7a. In this case, for example, if a labyrinth structure, an oil separator, a filter, etc. for separating the oil component in the blow-by gas are provided in the internal space 13 of the cylinder head cover 1d, the fuel component in the blow-by gas is mainly captured. A filter having a hollow fiber membrane to be collected can be employed.

  In the above embodiment, the fuel component collected by the filter 30 is separated from the filter 30 and returned to the crank chamber 14. However, the present invention is not limited to this. For example, a predetermined amount of fuel component is collected. The filter 30 or the filter medium (hollow fiber membrane 32) may be periodically replaced.

  In the above-described embodiment, the negative pressure is applied to the communication path 37 by the operation of the pump 39 so that the fuel component is sucked and separated from the filter 30. However, the present invention is not limited to this. Alternatively or additionally, a negative pressure generated in the intake pipe 7 a may be applied to the communication path 37 so that the fuel component is sucked and separated from the filter 30.

  In the above embodiment, the fuel dilution sensor 40 is provided in the cylinder head cover 1d. However, the present invention is not limited to this. For example, the fuel dilution sensor 40 may be provided in the blow-by gas passage 23. Further, instead of or in addition to the fuel dilution sensor 40, an oxygen sensor that detects the oxygen concentration in the blow-by gas may be employed.

  Furthermore, in the said Example, although the filter 30 which collects the fuel component in blow-by gas was employ | adopted as a collection means, it is not limited to this, For example, the fuel component in blow-by gas is adsorbed and collected. A canister having an adsorbent such as granular activated carbon may be employed.

  It is widely used as a technique for separating fuel components contained in blow-by gas generated in an internal combustion engine.

It is a longitudinal cross-sectional view of an engine provided with the fuel separator which concerns on a present Example. It is explanatory drawing for demonstrating the effect | action of the said fuel separator, (a) shows the conduction | electrical_connection state of a bypass passage, (b) shows the non-conduction state of a bypass passage. It is a principal part longitudinal cross-sectional view of an engine provided with the fuel separator of another form.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Engine, 1d; Cylinder head cover, 7a; Intake pipe, 13; Interior space, 14; Crank chamber, 20; Fuel separator, 21; Blow-by gas recirculation part, 23, 43; 29; bypass passage, 30; filter, 34; three-way solenoid valve, 37; communication path, 38; three-way solenoid valve, 41;

Claims (6)

Blow-by gas recirculation means for recirculating blow-by gas generated in the internal combustion engine to the intake system;
A bypass passage provided around the blowby gas passage in the blowby gas passage constituting the blowby gas recirculation means;
A collecting means for collecting a fuel component provided in the blow-by gas provided in the bypass passage and flowing through the bypass passage;
A fuel separation device comprising: a passage switching means for conducting one of the bypass passage and a part of the blowby gas passage based on the concentration of the fuel component contained in the blowby gas. .   The fuel separator according to claim 1, further comprising a detaching unit that detaches the fuel component collected by the collecting unit from the collecting unit and returns the fuel component to the crank chamber of the internal combustion engine.   The detaching means is included in the blow-by gas, a communication path that connects the upstream side of the collection means of the bypass passage and the crank chamber of the internal combustion engine, an electromagnetic valve for opening and closing the communication path, and The fuel separation device according to claim 1, further comprising a control device that controls the operation of the electromagnetic valve based on a concentration of a fuel component.   The passage switching means controls the operation of the solenoid valve based on a concentration of a fuel component contained in the blow-by gas, and a solenoid valve that conducts one of the bypass passage and a part of the blow-by gas passage. The fuel separation device according to any one of claims 1 to 3, further comprising:   The fuel separator according to any one of claims 1 to 4, wherein the blow-by gas passage is a passage that connects a crank chamber of the internal combustion engine and the intake system.   5. The fuel separation device according to claim 1, wherein the blow-by gas passage is a passage that communicates an internal space of a cylinder head cover of the internal combustion engine and the intake system. 6.

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