JP6812396B2 - PCV valve mounting structure - Google Patents

Description

The present invention relates to a mounting structure for a PCV valve.

The internal combustion engine mounted on a vehicle or the like is provided with a blow-by gas reduction device for returning the blow-by gas of the engine to the intake system. The device has a blow-by gas passage for flowing the blow-by gas to the intake system of the internal combustion engine, and also has a PCV valve for adjusting the gas flow area of the blow-by gas passage. Such a PCV valve is provided in the blow-by gas passage, and is attached to an internal combustion engine, for example, as shown in Patent Document 1. Specifically, the PCV valve is attached to the internal combustion engine so as not to come off by bolting the PCV valve to the internal combustion engine.

Japanese Unexamined Patent Publication No. 2011-236854

As shown in Patent Document 1, if the PCV valve is bolted to the internal combustion engine, the PCV valve is less likely to come off from the internal combustion engine, but the user releases the bolt fastening and removes the PCV valve from the internal combustion engine. It is also possible that it will end up. In this case, there is a problem that the blow-by gas of the internal combustion engine is released into the atmosphere through the portion of the internal combustion engine to which the PCV valve is attached.

An object of the present invention is to provide a mounting structure for a PCV valve capable of preventing blow-by gas from being released into the atmosphere due to the PCV valve coming off the internal combustion engine.

Hereinafter, means for solving the above problems and their actions and effects will be described.
The PCV valve mounting structure that solves the above problems is applied to the PCV valve for adjusting the gas flow area of the blow-by gas passage that allows the blow-by gas of the internal combustion engine to flow to the intake system of the engine. It is for attaching the valve to the internal combustion engine. In this PCV valve mounting structure, the PCV valve is non-removably mounted on the internal combustion engine.

According to the above configuration, since the PCV valve is non-removably attached to the internal combustion engine, it is possible to prevent the user from removing the PCV valve from the internal combustion engine, which in turn causes the PCV valve to be removed from the internal combustion engine. It will be possible to prevent the release of blow-by gas into the atmosphere.

The PCV valve mounting structure that solves the above problems is applied to the PCV valve for adjusting the gas flow area of the blow-by gas passage through which the blow-by gas of the internal combustion engine flows to the intake system of the engine. It is for attaching the valve to the internal combustion engine. The mounting structure of the PCV valve is separate from the PCV valve and includes a mounting member for mounting the PCV valve to the internal combustion engine in a non-removable manner.

According to the above configuration, since the PCV valve is non-removably attached to the internal combustion engine by the mounting member, it is possible to prevent the user from removing the PCV valve from the internal combustion engine, and thus the PCV valve is removed from the internal combustion engine. It becomes possible to prevent the release of blow-by gas into the atmosphere due to the detachment.

The schematic which shows the whole internal combustion engine to which the mounting structure of a PCV valve is applied. The cross-sectional view which shows the mounting structure of a PCV valve. FIG. 2 is a cross-sectional view showing a mounting structure of a PCV valve. The perspective view which shows the mounting structure of a PCV valve. The cross-sectional view which shows the mounting structure of a PCV valve. FIG. 2 is a cross-sectional view showing a mounting structure of a PCV valve. FIG. 6 is a cross-sectional view showing another example of the mounting structure of the PCV valve. FIG. 6 is a cross-sectional view showing another example of the mounting structure of the PCV valve.

[First Embodiment]
Hereinafter, the first embodiment of the mounting structure of the PCV valve will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, in an internal combustion engine, a cylinder head 2 is attached to the upper end portion of the cylinder block 1 and a crankcase 3 is attached to the lower end portion of the cylinder block 1. Further, the upper portion of the cylinder head 2 is covered with a resin head cover 4.

By the way, in an internal combustion engine, when fuel is burned in a combustion chamber, blow-by gas leaks from the combustion chamber into the crankcase 3. Therefore, the internal combustion engine is provided with a blow-by gas reduction device for circulating the gas (including blow-by gas) in the crankcase 3 to the intake system (intake passage 5) of the engine. The device has a blow-by gas passage 6 for flowing blow-by gas in the crankcase 3 to the intake passage 5, and also includes a PCV valve 7 for adjusting the gas flow area of the blow-by gas passage 6.

The PCV valve 7 is attached to the head cover 4. One end of the hose 8 is connected to the PCV valve 7, and the other end of the hose 8 is connected to the intake passage 5 of the internal combustion engine. The blow-by gas passage 6 communicates with the crankcase 3, passes through the cylinder block 1 and the cylinder head 2, passes through the inside of the head cover 4, and passes through the inside of the PCV valve 7 and the hose 8. It communicates with the intake passage 5.

Therefore, the PCV valve 7 is provided in the middle of the blow-by gas passage 6, and the intake air is taken from the crankcase 3 through the blow-by gas passage 6 through the adjustment of the gas flow rate in the blow-by gas passage 6 by the PCV valve 7. The flow rate of the gas flowing through the passage 5 changes.

Next, the mounting structure of the PCV valve 7 with respect to the head cover 4 will be described.
As shown in FIG. 2, the PCV valve 7 includes a cylindrical housing 9. A male screw portion 10 is formed on the outer peripheral surface of the lower end portion of the housing 9, and a flange 11 is formed on the outer peripheral surface of the upper end portion of the housing 9. Further, a seal ring 12 is provided between the male screw portion 10 and the flange 11 on the outer peripheral surface of the housing 9.

On the other hand, the head cover 4 is formed with a mounting hole 13 for mounting the PCV valve 7, and the inner peripheral surface of the mounting hole 13 is formed with a female screw portion 13a into which the male screw portion 10 of the housing 9 of the PCV valve 7 is screwed. ing. When the male screw portion 10 of the housing 9 is screwed into the female screw portion 13a of the mounting hole 13, the flange 11 of the housing 9 is located on the outside of the head cover 4 (upper side in FIG. 2) and comes into contact with the head cover 4. On the other hand, the seal ring 12 seals between the outer peripheral surface of the housing 9 and the inner peripheral surface of the mounting hole 13.

An inflow port 14 communicating with the inside of the head cover 4 is formed on the end surface (lower end surface of FIG. 2) of the housing 9 on the male screw portion 10 side. Further, a protruding portion 17 for connecting the hose 8 is formed on the end surface (upper end surface in FIG. 2) of the housing 9 on the flange 11 side, and the protruding portion is the outlet 15 communicating with the inside of the hose 8. Is formed. Then, the gas inside the head cover 4 flows into the housing 9 from the inflow port 14, and then flows out from the inside of the housing 9 into the hose 8 through the outflow port 15.

On the upper side of the flange 11 of the PCV valve 7, a plate-shaped mounting member 18 made of resin or metal, which is separate from the PCV valve 7, is provided. The mounting member 18 is for mounting the PCV valve 7 on the head cover 4, and is in contact with the flange 11 of the PCV valve 7. Further, a through hole 19 is formed in the mounting member 18, and a protruding portion 17 of the PCV valve 7 penetrates the through hole 19 from below to above. Further, a fixing hole 20 is formed on the side of the through hole 19 in the mounting member 18, and a caulking portion 21 projecting upward from the head cover 4 penetrates the fixing hole 20. The caulked portion 21 is plastically deformed so as to increase in diameter as shown by the solid line by applying heat after penetrating the fixing hole 20 as shown by the alternate long and short dash line.

As a result, the PCV valve 7 is irremovably attached to the head cover 4 of the internal combustion engine by the attachment member 18. Specifically, the PCV valve 7 is pressed toward the mounting hole 13 by the mounting member 18, whereby the PCV valve 7 is fixed to the head cover 4 so as not to come off from the mounting hole 13. Further, as described above, the mounting member 18 is attached to the head cover 4 by the plastic deformation of the caulking portion 21, so that the PCV valve 7 cannot be removed from the head cover 4.

Next, the operation and effect of the mounting structure of the PCV valve 7 in this embodiment will be described.
(1) Since the PCV valve 7 is irremovably attached to the head cover 4 of the internal combustion engine by the mounting member 18, not only can the PCV valve 7 be prevented from coming off the head cover 4, but also the user can attach the PCV valve 7 to the head cover. It becomes possible to suppress the removal from 4. Therefore, it is possible to prevent the PCV valve 7 from coming off from the head cover 4 of the internal combustion engine and the blow-by gas released to the atmosphere.

(2) When a blow-by gas reduction device is provided in various internal combustion engines, it is desired to share the PCV valve 7 in order to realize cost reduction, but the mounting hole 13 of the head cover 4 is used for each of the various internal combustion engines. The positional relationship with the crimped portion 21 may be different. Even in such a case, by preparing a plurality of types of mounting members 18 corresponding to the positional relationship between the mounting holes 13 and the caulking portion 21 for each internal combustion engine, the PCV valve 7 is not changed. The valve 7 can be non-removably attached to the head cover 4, and the PCV valve 7 can be shared with various internal combustion engines.

[Second Embodiment]
Next, a second embodiment of the mounting structure of the PCV valve will be described with reference to FIGS. 3 and 4.

In the internal combustion engine to which the PCV valve 7 is applied, a separator for separating a liquid such as oil from the blow-by gas is provided in the middle of the blow-by gas passage 6. The PCV valve 7 of the present embodiment adjusts the gas flow area at a portion of the blow-by gas passage 6 corresponding to the separator.

As shown in FIG. 3, the PCV valve 7 is attached to the resin separator 31 in a state of being inclined with respect to the horizontal plane. The PCV valve 7 includes a flow rate adjusting unit 32 for adjusting the gas flow area of the blow-by gas passage 6, and a pipe connecting unit 33 for connecting the flow rate adjusting unit 32 to the hose 8. The blow-by gas of the internal combustion engine is separated from a liquid such as oil in the separator 31 and then flows to the hose 8 via the PCV valve 7 (flow rate adjusting portion 32, pipe connecting portion 33). Therefore, the blow-by gas passage 6 through which the blow-by gas flows passes through the inside of the separator 31, the PCV valve 7, and the hose 8.

The flow rate adjusting unit 32 of the PCV valve 7 includes a cylindrical housing 32a that is inserted into a mounting hole 35 formed in the separator 31. A communication hole 34 that communicates with the inside of the separator 31 is formed at the end of the housing 32a on the side opposite to the end on the pipe connection portion 33 side. Further, on the outer peripheral surface of the housing 32a, a flange 32b is formed having a diameter larger than that of the mounting hole 35 of the separator 31 and in contact with a portion of the outer surface of the separator 31 around the opening of the mounting hole 35. Has been done. Further, the outer peripheral surface of the housing 32a corresponding to the inner peripheral surface of the mounting hole 35 is brought into contact with the inner peripheral surface between the outer peripheral surface of the housing 32a and the inner peripheral surface of the mounting hole 35. A seal ring 12 for sealing is provided.

Inside the housing 32a, a cylindrical movable member 36 extending on the same axis as the housing 32a, a spring 37 for urging the movable member 36 toward the communication hole 34, and a piping connection portion in the housing 32a. A ring 38 fitted on the inner peripheral surface of the opening on the 33 side is provided. Further, the pipe connection portion 33 includes a cylindrical housing 33a that is fitted into the opening on the pipe connection portion 33 side of the housing 32a of the flow rate adjusting portion 32 and sandwiches the ring 38 between the pipe connection portion 33 and the housing 32a. .. The inside of the housing 33a communicates with the inside of the housing 32a of the flow rate adjusting unit 32 via the ring 38. Further, a flange 33c is formed at the end of the housing 33a of the pipe connecting portion 33 on the flow rate adjusting portion 32 side, and the end of the housing 33a opposite to the flange 33c has the above-mentioned outer peripheral surface. A protruding portion 33b into which the hose 8 is fitted is formed.

The movable member 36 in the housing 32a of the flow rate adjusting unit 32 is urged toward a position where the communication hole 34 of the housing 32a is closed by the urging force of the spring 37. Further, the end portion of the movable member 36 on the pipe connecting portion 33 side is inserted inside the ring 38. The outer peripheral surface of the movable member 36 has a smaller diameter than the inner peripheral surface of the ring 38, and the portion closer to the communication hole 34 has a larger diameter. Since the intake negative pressure of the internal combustion engine acts in the hose 8 and in the housing 33a of the pipe connection portion 33, the movable member 36 moves to the pipe connection portion 33 side against the urging force of the spring 37 based on the intake negative pressure. Moving. Then, when the movable member 36 moves to the pipe connecting portion 33 side, the communication hole 34 of the housing 32a blocked by the movable member 36 is opened. Then, when the communication hole 34 is opened, the blow-by gas in the separator 31 in the internal combustion engine flows to the hose 8 via the PCV valve 7 (flow rate adjusting unit 32, pipe connecting unit 33).

The flow rate of blow-by gas at this time changes depending on the relative position between the movable member 36 and the ring 38. That is, during low-load operation of the internal combustion engine, the movable member 36 moves most to the pipe connecting portion 33 side. At this time, since the large diameter portion of the outer peripheral surface of the movable member 36 faces the inner peripheral surface of the ring 38, the gas flow area between the outer peripheral surface and the inner peripheral surface becomes smaller, which in turn reduces the PCV valve. The flow rate of blow-by gas passing through 7 is reduced. Then, as the engine operating state increases, the amount of movement of the movable member 36 against the urging force of the spring 37 toward the pipe connection portion 33 becomes smaller. As a result, as the engine load increases, the gas flow area between the outer peripheral surface and the inner peripheral surface increases, and as a result, the flow rate of blow-by gas passing through the PCV valve 7 increases. A spring 44 is provided in the housing 33a of the pipe connecting portion 33 to prevent the movable member 36 from moving excessively toward the pipe connecting portion 33.

Next, the mounting structure of the PCV valve 7 with respect to the separator 31 will be described.
As shown in FIGS. 3 and 4, the PCV valve 7 is attached to the separator 31 by using a metal plate-shaped attachment member 39. The mounting member 39 is formed in a plate shape bent by approximately 90 °. Further, the mounting member 39 is a fixing portion 40 fixed to the separator 31 and extending substantially horizontally on the upper side of the PCV valve 7, and a housing 33a of the pipe connecting portion 33 of the PCV valve 7 extending downward from the fixing portion 40. It is provided with an abutting portion 41 that sandwiches the entire flow rate adjusting portion 32 with the separator 31 by abutting on the flange portion 33c.

The contact portion 41 of the mounting member 39 is attached to the flange portion 33c of the housing 33a of the pipe connection portion 33 in a state where the protrusion 33b of the pipe connection portion 33 of the PCV valve 7 is sandwiched from both sides in the radial direction of the protrusion 33b. It is in contact. Further, a fixing hole 42 is formed in the fixing portion 40 of the mounting member 39 as shown in FIG. 3, and a resin caulking portion 43 projecting upward from the separator 31 penetrates the fixing hole 42. The caulked portion 43 is plastically deformed so as to increase in diameter as shown by the solid line by applying heat after penetrating the fixing hole 20 as shown by the alternate long and short dash line in FIG. As a result, at least the flow rate adjusting portion 32 of the PCV valve 7, specifically, the pipe connecting portion 33 and the flow rate adjusting portion 32 are irremovably attached to the separator 31 of the internal combustion engine by the attachment member 39.

Next, the operation and effect of the mounting structure of the PCV valve 7 in the present embodiment will be described. In addition, in this embodiment, in addition to the same effects as in (1) and (2) of the first embodiment, the following effects can be obtained.

(3) When the portion (hose 8) connecting the intake passage 5 of the internal combustion engine and the PCV valve 7 in the blow-by gas passage 6 is released from the PCV valve 7 due to an external impact or the like, the hose 8 is released. Since the air is sucked into the internal combustion engine through the air, the amount of intake air of the internal combustion engine rapidly increases and the engine stalls. Then, the stall of the internal combustion engine makes it possible to detect the disconnection of the hose 8 from the PCV valve 7. However, if the hose 8 is connected to the flow rate adjusting section 32 via the pipe connecting portion 33 of the PCV valve 7, and the flow rate adjusting section 32 is disconnected from the internal combustion engine (separator 31) due to an external impact or the like, the hose The increase in the amount of air intake when the air is sucked into the internal combustion engine via 8 is limited by the flow rate adjusting unit 32. As a result, the intake air amount of the internal combustion engine does not suddenly increase, and it becomes difficult to detect the disconnection of the hose 8 and the flow rate adjusting unit 32 from the separator 31 by utilizing the stall of the engine due to the sudden increase. In this respect, in the present embodiment, the mounting member 39 can prevent the flow rate adjusting portion 32 of the PCV valve 7 from being disconnected from the separator 31 while being connected to the hose 8 due to an impact from the outside or the like. Therefore, the above-mentioned problem that it becomes difficult to detect the disconnection of the hose 8 from the separator 31 does not occur.

(4) When the portion (hose 8) connecting the intake passage 5 of the internal combustion engine and the PCV valve 7 in the blow-by gas passage 6 is separated from the PCV valve 7 due to an external impact or the like and is opened to the atmosphere, the PCV valve 7 The inside of the housing 33a of the pipe connecting portion 33 in the above is also open to the atmosphere. At this time, since the movable member 36 is held at a position where the communication hole 34 is closed by the urging force of the spring 37, the blow-by gas of the internal combustion engine existing in the separator 31 is released to the atmosphere through the PCV valve 7. Can be suppressed.

[Third Embodiment]
Next, a third embodiment of the mounting structure of the PCV valve will be described with reference to FIGS. 5 and 6.

5 and 6 show how the PCV valve 7 is attached to the separator 31. As can be seen from these figures, the PCV valve 7 is attached to the separator 31 using a metal attachment member 51. In the PCV valve 7, the housing 32a of the flow rate adjusting unit 32 is inserted into the mounting hole 35 of the separator 31, and the flange 32b of the housing 32a is around the opening of the mounting hole 35 on the outer surface of the separator 31. It is in contact with the part.

The mounting member 51 is formed with a through hole 52 through which the protruding portion 33b of the housing 33a in the pipe connecting portion 33 of the PCV valve 7 penetrates. A plurality of legs 53 (two in this example) protruding toward the separator 31 side are formed. Bolts 54 and 55 penetrate through the portions of the mounting member 51 corresponding to the legs 53, respectively, as shown in FIG. 5, and the mounting member 51 is connected to the separator 31 by fastening the bolts 54 and 55 to the separator 31. Is fixed to.

As shown in FIG. 6, when the mounting member 51 is fixed to the separator 31, the tip of the leg 53 in the protruding direction is in contact with the separator 31, and the portion of the mounting member 51 around the through hole 52 is connected to the pipe. The entire flow rate adjusting portion 32 of the PCV valve 7 is sandwiched between the separator 31 and the flange portion 33c of the housing 33a of the portion 33.

As for one of the bolts 54 and 55, a so-called decapitation bolt is used in which the head portion 55a is cut off when the fastening to the separator 31 is completed so that the bolt 55 cannot be removed. By attaching the mounting member 51 to the separator 31 using such a bolt 55, at least the flow rate adjusting portion 32 of the PCV valve 7, specifically, the pipe connecting portion 33 and the flow rate adjusting portion 32 are separated by the mounting member 51 of the internal combustion engine. It is non-removably attached to 31.

Therefore, in this embodiment as well, the same effects as those in the second embodiment can be obtained.
[Other Embodiments]
In addition, each of the above-mentioned embodiments can be changed as follows, for example.

-In the first embodiment, as shown in FIG. 7, a welded portion 22 may be formed on the head cover 4, and a portion of the mounting member 18 corresponding to the welded portion 22 may be welded to the welded portion 22. .. In this case, the PCV valve 7 is irremovably attached to the head cover 4 by the attachment member 18 due to the welding of the attachment member 18 to the welded portion 22. In this case, a resin material is used as the mounting member 18.

-In the first embodiment, as shown in FIG. 8, the PCV valve 7 may be attached to the head cover 4 by the heat shrink tube 23. In this case, an annular protrusion 24 that surrounds the outer circumference of the flange 11 of the PCV valve 7 is formed around the opening of the mounting hole 13 in the head cover 4, and as shown by a two-dot chain line around the outer circumference of the annular protrusion 24, before heat shrinkage. A cylindrical heat shrink tube 23 is arranged. Then, by applying heat to the heat-shrinkable tube 23, the tube 23 is shrunk as shown by a solid line. As a result, the PCV valve 7 is irremovably attached to the head cover 4 by the heat shrink tube 23. In this case, the heat-shrinkable tube 23 serves as a mounting member for irremovably attaching the PCV valve 7 to the internal combustion engine.

-In the first to third embodiments, the mounting members 18, 39, 51 do not necessarily have to be made of metal, and may be formed of other materials such as resin. In this case, the mounting members 18, 39, 51 may be irremovably attached to the resin head cover 4 or separator 31 by various welding such as vibration welding, ultrasonic welding, hot plate welding, and laser welding. ..

-In the first to third embodiments, the head cover 4 and the separator 31 do not necessarily have to be made of resin. For example, the head cover 4 and the separator 31 may be made of metal, and the attachment members 18 and 39 may be attached to them in a non-removable manner by rivets, welding, or the like. When the mounting members 18, 39, 51 are made of resin, the mounting members 18, 39, 51 may be non-removably attached to the head cover 4 or the separator 31 by heat caulking or the like.

-In the first to third embodiments, the PCV valve 7 does not necessarily have to be attached to the head cover 4 or the separator 31, but may be attached to the cylinder head 2 or attached to the cylinder block 1. It may be something that can be done.

-In the first to third embodiments, the PCV valve 7 may be non-removably attached to the head cover 4 or the separator 31 without using the attachment members 18, 39, 51. For example, the protrusion amount of the flanges 11 and 32b may be increased so that the flanges 11 and 32b are directly attached directly to the head cover 4 and the separator 31 so as not to be removable.

1 ... Cylinder block, 2 ... Cylinder head, 3 ... Crankcase, 4 ... Head cover, 5 ... Intake passage, 6 ... Blow-by gas passage, 7 ... PCV valve, 8 ... Hose, 9 ... Housing, 10 ... Male thread, 11 ... Flange, 12 ... Seal ring, 13 ... Mounting hole, 13a ... Female threaded part, 14 ... Inlet, 15 ... Outlet, 17 ... Protruding part, 18 ... Mounting member, 19 ... Through hole, 20 ... Fixing hole, 21 ... Caulking Part, 22 ... Welding part, 23 ... Heat shrinkable tube, 24 ... Annular projection, 31 ... Separator, 32 ... Flow control part, 32a ... Housing, 32b ... Flange, 33 ... Piping connection part, 33a ... Housing, 33b ... Protruding part , 33c ... Flange, 34 ... Communication hole, 35 ... Mounting hole, 36 ... Movable member, 37 ... Spring, 38 ... Ring, 39 ... Mounting member, 40 ... Fixed part, 41 ... Contact part, 42 ... Fixed hole, 43 ... caulking part, 44 ... spring, 51 ... mounting member, 52 ... through hole, 53 ... leg part, 54 ... bolt, 55 ... bolt, 55a ... head.

Claims (2)

It is applied to the PCV valve for adjusting the gas flow area of the blow-by gas passage that allows the blow-by gas of the internal combustion engine to flow to the intake system of the engine, and in the mounting structure of the PCV valve that attaches the PCV valve to the internal combustion engine.
A mounting structure for a PCV valve, which is separate from the PCV valve and includes a mounting member for mounting the PCV valve to an internal combustion engine so as not to be removable. The PCV valve includes a flow rate adjusting unit for adjusting the gas flow area of the blow-by gas passage.
The PCV valve mounting structure according to claim 1 , wherein the mounting member is for mounting the flow rate adjusting portion to an internal combustion engine so as not to be removable.