JP2009216064A - Blowby gas reduction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the maintainability of a PCV valve and the support rigidity of an intake unit to an engine body by eliminating a post-assembly pipe connecting an oil separation chamber to an intake passage. <P>SOLUTION: A blowby gas reduction device is provided with the intake unit having an inlet-side pipe for mounting a throttle body thereto and guiding intake air to an intake port of the engine body, and a cover mounted to an intake side and having the oil separation chamber. In the blowby gas reduction device, a blowby gas exhaust hole is formed at the cover, and the intake unit is connected to the inlet-side pipe part. The blowby gas reduction device is provided with: a tubular part extended outward from the engine body and having both ends opened; a lid material connected to the tubular part to make the inside of the tubular part communicate with the inside of the intake unit by fixing one-side end of the tubular part to a cover member to make the inside of the tubular part communicate with the oil separation chamber by facing one-side end of the engine body of the tubular part to the exhaust hole, and mounted to the other-side end of the tubular part to seal the other-side end; and a PCV valve detachably arranged on the tubular part or the cover member on the blowby gas upstream side relative to the communication part, and extractable from the tubular part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a blow-by gas reduction device that recirculates blow-by gas to an intake passage.

  In a reciprocating engine, unburned gas may leak into the crankcase as blow-by gas from between the piston ring and the cylinder. In order to prevent the blow-by gas from being released to the atmosphere, a reduction device that recirculates to the intake passage is provided. In this type of reducing device, an oil separation chamber is provided in a passage through which blow-by gas passes to separate oil mist, and the blow-by gas is recirculated during intake using negative intake pressure.

  The oil separation chamber can be formed by using the space inside the engine body and the head cover, or by mounting a cover member on the side of the intake side of the engine body, for example, the cylinder block, and utilizing the internal space. There are those formed, and those formed side by side to form two reflux systems. Further, a PCV valve is provided in the middle of the passage through which blow-by gas passes to prevent the intake air from flowing back into the oil separation chamber (Patent Document 1).

  In general, a retrofit pipe is used for connection between the oil separation chamber and the intake passage. However, when retrofitted piping is used, there are problems such as an increase in the number of parts and a decrease in assembly workability. In view of this, Patent Document 2 discloses a configuration in which a head cover and an intake manifold are integrally formed, and a retrofit pipe connecting an oil separation chamber and an intake passage in the head cover is eliminated. Patent Document 2 also discloses providing an opening for performing maintenance of the PCV valve.

JP 2002-106429 A JP-A-11-117722

  However, the thing of patent document 2 is made into what formed the oil separation chamber in the head cover, and is difficult to apply to what formed the oil separation chamber in the side part of the intake side of an engine main body. On the other hand, the intake manifold is becoming popular as a unit made of light materials such as resin from the viewpoint of weight reduction, and the throttle body attached to it is made of metal and has a certain weight. Have. In general, since the throttle body is supported only by the intake unit, it is necessary to increase the support rigidity of the intake unit with respect to the engine body in order to prevent vibration of the intake unit and the throttle body due to vibration during vehicle running and engine vibration. is there.

  It is an object of the present invention to eliminate the retrofit piping connecting the oil separation chamber and the intake passage, to improve the maintainability of the PCV valve, and to increase the support rigidity of the intake unit with respect to the engine body.

  According to the present invention, the intake side of the engine body is attached to the intake side of the engine body, and the throttle body has an inlet side pipe part attached to the end part, and the intake air passing through the inlet side pipe part is supplied to the intake port of the engine body. An engine blow-by comprising: an intake unit that forms a leading intake passage; and a cover member that is mounted on the side of the intake side and forms an oil separation chamber that separates oil from blow-by gas introduced from the inside of the engine body. In the gas reduction device, the cover member has a discharge hole for discharging the blow-by gas from which oil has been separated in the oil separation chamber, and the intake unit is connected to the inlet side pipe portion and the engine A cylindrical portion that extends from the main body side to the outside of the engine main body and that is open at both ends, is connected to the cylindrical portion, and the end of the cylindrical portion is The one end of the tubular portion is fixed to the cover member so that the inner space of the tubular portion and the oil separation chamber communicate with each other with the one end on the main body side facing the discharge hole And a communication portion that communicates the internal space of the cylindrical portion and the internal space of the intake unit, and is detachably attached to the other end portion of the cylindrical portion, and the other end portion is sealed. A lid member that stops, and is detachably provided in the cylindrical portion or the cover member on the upstream side of the communication portion in the flow direction of the blow-by gas, and passes through the internal space of the cylindrical portion and the cylinder And a PCV valve provided at a position where it can be taken out from the other end of the shape portion.

  In the blow-by gas reduction device of the present invention, the tubular part and the communication part are provided in the intake unit, so that a retrofit pipe connecting the oil separation chamber and the intake passage can be eliminated. Since the PCV valve is provided at a position where it can be taken out from the other end of the cylindrical portion through the internal space of the cylindrical portion, the PCV valve can be removed without removing the intake unit from the engine body. Can be maintained. Furthermore, since the cylindrical part is connected to the inlet side pipe part, the support rigidity of the intake unit in the vicinity of the throttle body can be increased. The cylindrical portion serves as a part of a blow-by gas passage between the oil separation chamber and the intake passage, a maintenance passage of the PCV valve, and a support rigid member of the intake unit. By achieving the above, these can be realized while avoiding an increase in the number of parts.

  In the present invention, the intake unit is connected to the inlet side pipe part, and is connected to a surge tank part extending in the front-rear direction of the engine body, and a lower part of the surge tank part. A branch passage portion connected to the intake port through the outside of the engine body, and the cylindrical portion extends in a direction substantially parallel to a direction orthogonal to the front-rear direction of the engine body. Good. According to this configuration, the vertical vibration of the intake unit can be more effectively suppressed.

  In the present invention, the fixing portion may be fixed to the engine body by a fastening member with a part of the cover member interposed therebetween. According to this configuration, the support rigidity of the intake unit can be increased without increasing the strength of the entire cover member.

  In this case, the engine body has a flange portion that forms a mounting surface with the cover member, and the fixing portion is fixed to the flange portion by the fastening member with a part of the cover member interposed therebetween. Also good. According to this configuration, it is possible to improve workability of attaching the cover member to the engine body and attaching the fixing portion to the engine body.

  In the present invention, the intake unit may be made of resin. According to this configuration, both the weight reduction of the intake unit and the improvement of the support rigidity can be achieved.

  As described above, according to the present invention, it is possible to eliminate the retrofit piping connecting the oil separation chamber and the intake passage, improve the maintainability of the PCV valve, and increase the support rigidity of the intake unit with respect to the engine body. .

  FIG. 1 is a view of an engine A to which a blow-by gas reduction device according to an embodiment of the present invention is applied as viewed from the rear side. Engine A is an inline 4-cylinder gasoline engine. The longitudinal direction of the engine A is determined by the direction of the crankshaft (not shown), in other words, the cylinder row direction, and the transmission side is called the rear part and the opposite side is called the front part. In the present embodiment, the case where the present invention is applied to an in-line four-cylinder gasoline engine is illustrated, but the present invention is also applicable to other engines having different numbers of cylinders, cylinder arrangements, and the like.

  The engine A includes an engine body 1. The engine body 1 includes a cylinder head 2 and a cylinder block 3. A head cover 4 is provided on the upper part of the cylinder head 2. An oil pan 5 is provided at the lower part of the cylinder block 3.

  An intake unit 10 is mounted on the intake side of the engine body 1. Hereinafter, the configuration of the intake unit 10 will be described with reference to FIGS. 1 and 2. FIG. 2 is a view of the intake unit 10 as viewed from the side of the mounting surface to the engine body 1. That is, FIG. 2 is a view of the intake unit 10 viewed from the engine body 1 side.

  The intake unit 10 is connected to the inlet side pipe part 11, the inlet side pipe part 11, is connected to the hollow surge tank part 12 extending in the front-rear direction of the engine body 1, and the lower part of the surge tank part 12, and A branch passage portion 13 bent so as to be connected to an intake port (not shown) through the outside of the engine body 1 of the tank portion 12, and intake air passing through the inlet side pipe portion 11 is taken into the intake port of the engine body 1 An intake passage leading to is formed. In the case of this embodiment, the inlet side pipe part 11, the surge tank part 12, and the branch passage part 13 are resin.

  An attachment flange portion 11b of the throttle body 6 is formed at the end of the inlet side pipe portion 11, and the throttle body 6 is attached thereto. Since the engine A of the present embodiment is an in-line four-cylinder engine, four branch passage portions 13 are provided. At the end of the branch passage portion 13, an attachment portion 13 a is formed by collecting the end portions of the branch passage portions 13. The attachment portion 13 a is fixed to the peripheral wall of the intake port of the cylinder head 2 by the fixture 10 a. In the attachment portion 13a, two opening portions 13b are formed for each branch passage portion 13, and communicate with each intake port. That is, in this embodiment, there are two intake ports per cylinder. A fixing tool (stay) 10 b is provided at the lower part of the intake unit 10, and the fixing tool 10 b is fixed to the side of the cylinder block 3 on the intake side.

  A cylindrical portion 14 is connected to the inlet side pipe portion 11. In the case of the present embodiment, the cylindrical portion 14 is made of resin and is formed integrally with the inlet side pipe portion 11. The cylindrical portion 14 extends from the engine main body 1 side to the outside (intake side) of the engine main body 1, and the end portion 14a on the engine main body 1 side and the end portion 14b on the opposite side are both open. An internal space 14c described later is formed. As shown in FIG. 2, a groove 14d for inserting a sealing material is provided around the end surface of the end portion 14a around the opening 14c 'formed in the end portion 14a.

  A fixed portion 15 is connected to the tubular portion 14. In the case of this embodiment, the fixing portion 15 is made of resin and is formed integrally with the cylindrical portion 14. In the case of this embodiment, the fixing portion 15 is formed at the end portion 14a of the cylindrical portion 14, and the end portion 14a of the cylindrical portion 14 and the end surface of the fixing portion 15 form an oval shape as shown in FIG. Yes. A through hole 15 a is formed in the fixing portion 15.

  Next, FIG. 3A is a view showing a main part of the side of the intake side of the cylinder block 3. A flange portion 3 a to which a cover member 20 to be described later is attached is formed on the intake side side portion of the cylinder block 3. A plurality of screw holes 3b and one screw hole 3c are formed on the upper surface of the flange portion 3a, which is the mounting surface of the cover member 20. A plurality of ribs 3d are formed on the side of the intake side of the cylinder block 3 surrounded by the flange portion 3a, and a plurality of communication passages 3e communicating with the inside of the crankcase of the cylinder block 3 are opened.

  FIG. 3B is a view showing a mode in which the cover member 20 is mounted on the intake side of the cylinder block 3. The peripheral edge of the cover member 20 is aligned with the flange portion 3a, and the cover member 20 is attached and fixed to the intake side portion of the cylinder block 3 by screwing a bolt into the screw hole 3b. In the case of this embodiment, the cover member 20 is made of resin, and includes a separation chamber forming portion 21 that forms an oil separation chamber 20a described later, and a joint portion 22 that attaches the end portion 14a and the fixing portion 15 of the cylindrical portion 14. Have The joint portion 22 includes a discharge hole 22a that communicates with the opening portion 14c 'of the end portion 14a of the cylindrical portion 14 and a through hole 22b that communicates with the screw hole 3c when assembled.

  FIG. 4A is a cross-sectional view of the periphery of the oil separation chamber 20a along the line II in FIG. The peripheral edge of the cover member 20 is in airtight contact with the upper surface of the flange portion 3a on the side of the intake side of the cylinder block 3 via the sealing material 7, and the separation chamber forming portion 21 is cranked via the communication passage 3e. An oil separation chamber 20a into which blow-by gas is introduced from the case is formed. A baffle plate portion 21 a is erected on the inner wall of the separation chamber forming portion 21. A hole 21 b communicating with the discharge hole 22 a is formed in the inner wall of the separation chamber forming part 21.

  The blow-by gas introduced into the separation chamber forming portion 21 from the crankcase through the communication passage 3e is formed on the zigzag as indicated by the arrows in FIG. The oil mist contained in the blow-by gas is separated in the process. The blow-by gas from which the oil mist has been separated is guided from the hole 21b to the discharge hole 22a. The separated oil mist flows into the crankcase through the communication path 3e and finally flows into the oil pan 5.

  FIG. 4B is a cross-sectional view around the cylindrical portion 14 and the cover member 20 along the line II-II in FIG. 3B, and the end portion 14 a and the fixing portion 15 of the cylindrical portion 14 are connected to the joint portion 22. It is sectional drawing after attaching. As shown in the figure, the cylindrical portion 14 forms an internal space 14c. In the present embodiment, the internal space 14 has a columnar shape, and the cylindrical portion 14 is generally cylindrical. In the case of the present embodiment, the cylindrical portion 14 extends in a direction substantially parallel to a direction orthogonal to the front-rear direction of the engine body 1. More specifically, in the case of the present embodiment, the axial direction of the cylindrical portion 14 is a direction substantially parallel to the direction orthogonal to the front-rear direction of the engine body 1 and the outside of the engine from the intake side of the engine body 1 Oriented upward.

  The cylindrical part 14 and the inlet side pipe part 11 are cut off at their peripheral walls to form a communication part 14e, and the internal spaces are in communication with each other.

  A lid member 14b is attached to the end portion 14b of the cylindrical portion 14, and the end portion 14b is sealed, that is, the internal space 14c is not communicated with the outside air. A part of the lid member 14b is press-fitted into the end portion 14b to seal the end portion 14b. The lid member 14b is detachable so as to be detached from the end portion 14b when the lid member 14b is pulled out. In addition, it is good also as attachment or detachment by forming a screw in the inner peripheral surface of the opening part of the cover member 14b and the edge part 14b, and screwing.

  A bolt 16 that is a fastening member is inserted into the through hole 15a of the fixing portion 15. The bolt 16 passes through the through hole 22b of the joint portion 22 and is screwed into a screw hole 3c formed in the flange portion 3a. That is, in the case of this embodiment, the fixing portion 15 is fixed to the flange portion 3 a of the cylinder block 3 by the bolt 17 with the joint portion 22 that is a part of the cover member 20 interposed therebetween.

  As shown in the figure, when the bolt 16 is fastened, the opening 14c ′ of the end 14a of the cylindrical portion 14 faces the discharge hole 22a so that the internal space 14c of the cylindrical portion 14 and the oil separation chamber 20a communicate with each other. Thus, the end portion 14 a is fixed to the joint portion 22 of the cover member 20. The end surface of the end portion 14a abuts on the upper surface of the joint portion 22 through the seal material 8 inserted in the groove 14d for inserting the seal material, and blowby gas leaks at the boundary between the opening portion 14c ′ and the discharge hole 22a. Is prevented from occurring.

  Next, a PCV valve 18 is arranged upstream of the communication part 14e in the flow direction of the blow-by gas, that is, on the engine body 1 side. The PCV valve 18 prevents the back flow of the blow-by gas and adjusts the flow rate of the blow-by gas according to the magnitude of the negative pressure. In the case of this embodiment, the inner diameter is relatively small in the vicinity of the end portion 14a of the cylindrical portion 14, and the PCV valve 18 is press-fitted therein. When removing the PCV valve 18 for maintenance, for example, for replacement, the lid member 16 is removed and inserted into the internal space 14c from the end 14b side of the cylindrical portion 14, and the PCV valve 18 is inserted into the cylindrical portion. Pull out from 14. Next, a new PCV valve 18 is inserted into the internal space 14 c from the end portion 14 b side of the tubular portion 14, and is pressed and pressed into the vicinity of the end portion 14 a of the tubular portion 14. Thus, in the present embodiment, the PCV valve 18 is detachable via the internal space 14c of the cylindrical portion 14. Accordingly, it is not necessary to remove the intake unit 10 for maintenance of the PCV valve 18 after the intake unit 10 is mounted on the engine body 1.

  The attachment structure of the PCV 18 may be a screw structure, and may be detachably provided not on the cylindrical portion 14 but on the cover member 20 (joining portion 22) side. However, in any case, it is necessary to provide at a position where it can be taken out from the end portion 14b of the cylindrical portion 14 through the internal space 14c of the cylindrical portion 14.

  In the engine A of the present embodiment having such a configuration, when a negative pressure is generated in the intake unit 10 due to the opening / closing state of the throttle valve of the throttle body 6 and the lowering of a piston (not shown), the oil separation chamber 20a also has a negative pressure. Thus, blow-by gas is introduced into the oil separation chamber 20a from the crankcase through the communication passage 3e. The blow-by gas introduced into the oil separation chamber 20a is separated from the oil mist and guided to the internal space 14c of the cylindrical portion 14 through the hole 21b, the discharge hole 22a, and the PCV valve 18. Thereafter, due to the negative pressure in the intake unit 10, the blow-by gas is further introduced into the inlet side pipe portion 11 through the communication portion 14e and returned to the intake air.

  In the present embodiment, by providing the cylindrical portion 14 and the communication portion 14 e in the intake unit 10, it is possible to eliminate a retrofit pipe that connects the oil separation chamber 20 a and the intake passage in the intake unit 10. Since the PCV valve 18 is provided at a position where it can be taken out from the end portion 14b of the cylindrical portion 14 through the internal space 14c of the cylindrical portion 14, the PCV valve 18 can be removed without removing the intake unit 10 from the engine body 1. Maintenance can be performed.

  Further, since the cylindrical portion 14 is connected to the inlet side pipe portion 11, the support rigidity of the intake unit 10 in the vicinity of the throttle body 6 can be increased. The throttle body 6 is generally made of metal and has a certain amount of weight, but is only supported in a cantilevered manner on the inlet side pipe portion 11 of the intake unit 10. In the present embodiment, the throttle body 6 is Since the support rigidity of the intake unit 10 in the vicinity of the throttle body 6 can be increased, it is possible to prevent the vibration of the intake unit 10 and the throttle body 6 caused by the vibration during the traveling of the vehicle and the vibration of the engine A due to the presence of the throttle body 6. it can.

  Thus, in the present embodiment, the cylindrical portion 14 includes a part of the blow-by gas passage between the oil separation chamber 20a and the intake passage, the maintenance passage of the PCV valve 18, and the support rigid member of the intake unit 10. By fulfilling this role, these can be realized while avoiding an increase in the number of parts.

  Further, in the present embodiment, the cylindrical portion 14 extends in a direction substantially parallel to the direction orthogonal to the front-rear direction of the engine body A, so that the intake unit 10 is Restrained in a direction orthogonal to the direction, the vertical vibration can be more effectively suppressed.

  Further, since the fixing portion 15 is fixed to the engine main body 1 by the bolt 17 with a part of the cover member 20 (joining portion 22) interposed therebetween, the support of the intake unit 10 is supported without increasing the strength of the cover member 20 as a whole. For example, the thickness of the separation chamber forming portion 21 can be further reduced. Further, since the fixing portion 15 is fixed to the flange portion 3a by the bolt 17 with a part (joining portion 22) of the cover member 20 interposed therebetween, the fixing operation of the cover member 20 to the cylinder block 3 and fixing The workability of the work of attaching the portion 15 to the cylinder block 3 can be improved.

  Further, in the present embodiment, since the intake unit 10 is made of resin, it is possible to achieve both weight reduction of the intake unit 10 and improvement of support rigidity in the vicinity of a portion where the throttle body 6 that is a relatively heavy object is mounted.

  In addition, in this embodiment, although the cylindrical part 14 was formed in the substantially cylindrical shape, a rectangular tube shape may be sufficient. Further, a reinforcing rib may be joined between the tubular portion 14 and the inlet side pipe portion 11 or the surge tank 12, and in this case, the support rigidity of the intake unit 10 can be further increased.

  In the present embodiment, the communication portion 14e connects the internal space 14c of the cylindrical portion 14 and the internal space of the inlet side pipe portion 11, but the internal space 14c of the cylindrical portion 14 and the surge tank 12 You may make it connect internal space. Hereinafter, this example will be described with reference to FIG. FIG. 5A is a view of the intake unit 10 ′ viewed from the side of the mounting surface to the engine body 1, and FIG. 5B is a cross-sectional view around the cylindrical portion 14 and the cover member 20, FIG. ). Hereinafter, the same components as those of the intake unit 10 described above are denoted by the same reference numerals, and only different points will be described.

  As shown in FIG. 5A, in the intake unit 10 ′, a tubular communication portion 19 is integrally formed between the tubular portion 14 and the surge tank 12. As shown in FIG. 5B, one end of the communication portion 19 opens and communicates with the internal space 14 c of the cylindrical portion 14, while the other end opens and communicates with the internal space of the surge tank 12. As described above, the intake passage for returning the blowby gas may be the surge tank 12 in addition to the inlet side pipe portion 11.

It is the figure which looked at the engine A to which the blowby gas reduction apparatus which concerns on one Embodiment of this invention was applied from the rear part side. FIG. 2 is a view of the intake unit 10 as viewed from the side of the attachment surface to the engine body 1. (A) is a figure which shows the principal part of the intake side side part of the cylinder block 3, (b) is a figure which shows the aspect which attached the cover member 20 to the intake side side part of the cylinder block 3. FIG. (A) is sectional drawing of oil separation chamber 20a periphery along line II of FIG.3 (b), (b) is the cylindrical part 14 and cover member 20 periphery along line II-II of FIG.3 (b). FIG. (A) is the figure which looked at the intake unit 10 'from the attachment surface side to the engine body 1, and (b) is a sectional view around the cylindrical portion 14 and the cover member 20.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine body 6 Throttle body 10 Intake unit 11 Inlet side pipe part 20 Cover member 20a Oil separation chamber 22a Drain hole 14 Cylindrical part 14c Internal space 14e, 19 Communication part 15 Fixing part 16 Cover member 18 PCV valve

Claims (5)

An intake passage is mounted on the intake side of the engine body, and has an inlet side pipe portion to which the throttle body is mounted at the end, and forms an intake passage that guides the intake air passing through the inlet side pipe portion to the intake port of the engine body. An intake unit;
A cover member mounted on the side of the intake side and forming an oil separation chamber for separating oil from blow-by gas introduced from inside the engine body;
In an engine blow-by gas reduction device equipped with
The cover member is
A discharge hole for discharging the blow-by gas from which oil has been separated in the oil separation chamber;
The intake unit is
A tubular portion that is continuous with the inlet side pipe portion and extends outward from the engine body from the engine body side, with both ends open,
The internal space of the tubular portion and the oil separation chamber are communicated with each other so as to be continuous with the tubular portion and facing one end portion of the tubular portion on the engine body side toward the discharge hole. A fixing portion for fixing the one end portion of the cylindrical portion to the cover member;
A communication portion for communicating the internal space of the cylindrical portion and the internal space of the intake unit;
A lid member that is detachably attached to the other end of the cylindrical portion and seals the other end;
The other end of the tubular part is provided detachably in the tubular part or in the cover member upstream of the communication part in the flow direction of blow-by gas, and passes through the internal space of the tubular part. A PCV valve provided at a position where it can be removed from the unit,
A blow-by gas reduction device comprising: The intake unit is
A surge tank portion connected to the inlet side pipe portion and extending in the front-rear direction of the engine body;
A branch passage portion connected to the lower portion of the surge tank portion and connected to the intake port through the outside of the engine body of the surge tank portion;
The blow-by gas reduction device according to claim 1, wherein the cylindrical portion extends in a direction substantially parallel to a direction orthogonal to the front-rear direction of the engine body.   The blow-by gas reduction device according to claim 1, wherein the fixing portion is fixed to the engine body by a fastening member with a part of the cover member interposed therebetween. The engine body is
A flange portion that forms a mounting surface with the cover member;
The blow-by gas reduction device according to claim 3, wherein the fixing portion is fixed to the flange portion by the fastening member with a part of the cover member interposed therebetween.   The blow-by gas reduction device according to any one of claims 1 to 4, wherein the intake unit is made of resin.

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