Blow-by gas recirculation device

Abstract

To detect detachment of a PCV valve by using an inexpensive and simple configuration.SOLUTION: A blow-by gas recirculation device includes: a PCV valve mounted to an outer surface of an engine; a boss formed on the outer surface of the engine in an undetachable manner; and blow-by gas piping having a main pipe connected to an intake pipe, a first branch pipe branched from the main pipe and connected to the PCV valve in an undetachable manner and a second branch pipe branched from the main pipe and connected to the boss in a detachable manner.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a blow-by gas recirculation device. [Background technology]

[0002] Conventionally, in an engine, blow-by gas, which contains combustion gas and unburned mixture gas that have become high pressure during the combustion stroke, leaks out from the gap between the cylinder and the piston and accumulates in the crankcase. For this reason, a blow-by gas recirculation device is provided in the engine system to recirculate the blow-by gas to the intake passage. The blow-by gas recirculation device returns the blow-by gas in the crankcase to the intake passage and introduces it into the combustion chamber of the engine again.

[0003] Generally, a blow-by gas recirculation device has an oil separator, a PCV valve, and a blow-by gas pipe. The oil separator is installed in the engine and separates the oil in the blow-by gas. The PCV valve is connected to the oil separator and prevents the intake air from flowing back into the oil separator. The blow-by gas pipe is connected to the PCV valve and the intake pipe and recirculates the blow-by gas that has passed through the PCV valve to the intake passage in the intake pipe.

[0004] Patent Document 1 discloses a blow-by gas recirculation device in which a PCV valve is fixed to an oil separator by forming a contact portion that can contact the inner wall surface of the oil separator. The blow-by gas recirculation device of Patent Document 1 can prevent the PCV valve from coming off the oil separator. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-51332 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, if the PCV valve is fixed to the oil separator, when only the PCV valve breaks down, the entire engine block in which the oil separator is installed must be replaced, resulting in high replacement costs.In addition, if a dedicated detection device is installed to detect when the PCV valve has come off, additional harnesses and circuits are required, which creates the problem of complicating the configuration of the blow-by gas recirculation system.

[0007] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a blow-by gas recirculation device that is inexpensive and has a simple configuration and is capable of detecting that the PCV valve has been removed. [Means for solving the problem]

[0008] In order to solve the above problems, the blow-by gas recirculation device of the present invention comprises: The PCV valve is attached to the outside of the engine. A boss formed on an outer surface of the engine and not removable; a blow-by gas pipe including a main pipe connected to an intake pipe, a first branch pipe branched from the main pipe and inseparably connected to the PCV valve, and a second branch pipe branched from the main pipe and removably connected to the boss; Equipped with: Effect of the Invention

[0009] According to the present invention, it is possible to detect the removal of a PCV valve with an inexpensive and simple configuration. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of an engine system according to a first embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing the configuration of the first piping structure according to the first embodiment. [Diagram 3] FIG. 3 is a schematic diagram showing the configuration of the first piping structure in a state in which the first PCV valve is detached from the first oil separator. [Figure 4] FIG. 4 is a schematic diagram showing the configuration of the first piping structure according to the second embodiment. [Diagram 5] FIG. 5 is a schematic diagram showing the configuration of a connection member according to the second embodiment. [Figure 6] FIG. 6 is a schematic diagram showing the configuration of the first piping structure in a state in which the first PCV valve is detached from the first oil separator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific values ​​shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid repeated explanations, and elements not directly related to the present invention are not shown.

[0012] Fig. 1 is a schematic diagram showing a configuration of an engine system 1 according to a first embodiment. The engine system 1 according to the first embodiment is provided in a vehicle 10. As shown in Fig. 1, the engine system 1 includes an engine 100, an intake system 200, an exhaust system 300, and a blow-by gas recirculation device 400.

[0013] The engine 100 includes a cylinder block 102, a crankcase 104, a cylinder head 106, a rocker cover 108, and an oil pan 110. The crankcase 104 is formed integrally with the cylinder block 102. The cylinder head 106 is connected to an upper part of the cylinder block 102. The rocker cover 108 is connected to an upper part of the cylinder head 106. The cylinder head 106 is disposed between the cylinder block 102 and the rocker cover 108. The oil pan 110 is connected to a bottom part of the crankcase 104.

[0014] A plurality of cylinder bores 112 are formed in the cylinder block 102. A piston 114 is slidably supported in each of the cylinder bores 112 by a connecting rod 116. In the engine 100, a space surrounded by the cylinder bores 112, the cylinder head 106, and the crown surface of the piston 114 is formed as a combustion chamber 118.

[0015] In the engine 100, a space formed between the crankcase 104 and the oil pan 110 serves as a crank chamber 120. A crankshaft 122 is rotatably supported within the crank chamber 120. The piston 114 is connected to the crankshaft 122 via a connecting rod 116.

[0016] An intake port 124 and an exhaust port 126 are provided in the cylinder head 106 so as to communicate with the combustion chamber 118. The tip of an intake valve 128 is located between the intake port 124 and the combustion chamber 118, and the tip of an exhaust valve 130 is located between the exhaust port 126 and the combustion chamber 118.

[0017] In the engine 100, a space formed between the cylinder head 106 and the rocker cover 108 serves as a rocker chamber 132. An intake camshaft 134 and an exhaust camshaft 136 are rotatably supported in the rocker chamber 132.

[0018] A plurality of intake valve cams 134a are fixed to the intake camshaft 134. The intake valve cams 134a are in contact with the ends of the intake valves 128, and rotate with the rotation of the intake camshaft 134, thereby moving the intake valves 128 in the axial direction. As a result, the intake valves 128 open and close the space between the intake port 124 and the combustion chamber 118.

[0019] A plurality of exhaust valve cams 136a are fixed to the exhaust camshaft 136. The exhaust valve cams 136a are in contact with the ends of the exhaust valves 130, and rotate with the rotation of the exhaust camshaft 136, thereby moving the exhaust valves 130 in the axial direction. As a result, the exhaust valves 130 open and close the gap between the exhaust port 126 and the combustion chamber 118.

[0020] In addition, an injector and a spark plug (not shown) are provided in the cylinder head 106. Fuel injected from the injector into the combustion chamber 118 mixes with air supplied to the combustion chamber 118 via an intake port 124 to form an air-fuel mixture. The spark plug is then ignited at a predetermined timing, and the air-fuel mixture generated in the combustion chamber 118 is burned. This combustion causes the piston 114 to perform a reciprocating motion, and this reciprocating motion is converted into the rotational motion of the crankshaft 122 via the connecting rod 116.

[0021] The intake system 200 includes an intake pipe 202, an air cleaner 204, an intercooler 206, a throttle valve 208, and an intake manifold 210. The intake manifold 210 is connected to the upstream side of the intake port 124. An intake passage 220 is formed inside the intake pipe 202. The intake passage 220 communicates with the intake port 124. The engine system 1 of the first embodiment is also provided with a turbocharger TC. The turbocharger TC includes a compressor C and a turbine T.

[0022] An air cleaner 204, a compressor C, an intercooler 206, a throttle valve 208, and an intake manifold 210 are provided in the intake pipe 202 in this order from the upstream side to the downstream side. The intake air purified by the air cleaner 204 is introduced into the combustion chamber 118 through an intake flow path 220 and an intake port 124. The intake pipe 202 is roughly formed by an upstream intake pipe 202a located upstream of the compressor C and a downstream intake pipe 202b located downstream of the compressor C.

[0023] The exhaust system 300 includes a turbine T of a turbocharger TC, an exhaust pipe 302, a catalyst 304, a muffler 306, an A / F sensor 308, and a detection device 310. The exhaust pipe 302 is connected to the downstream side of the exhaust port 126. An exhaust flow path 320 is formed inside the exhaust pipe 302. The exhaust flow path 320 communicates with the exhaust port 126.

[0024] A turbine T of a turbocharger TC, an A / F sensor 308, a catalyst 304, and a muffler 306 are provided in this order from upstream to downstream in the exhaust pipe 302. Exhaust gas generated after combustion in the combustion chamber 118 is purified by the catalyst 304 as it passes through an exhaust flow path 320, and is discharged to the outside through the muffler 306.

[0025] The A / F sensor 308 is provided upstream of the catalyst 304 in the exhaust pipe 302. In the first embodiment, the A / F sensor 308 is disposed between the turbine T and the catalyst 304. The A / F sensor 308 detects the air-fuel ratio of the exhaust gas. A signal indicating the air-fuel ratio detected by the A / F sensor 308 is transmitted to the detection device 310. The detection device 310 derives the air-fuel ratio based on the signal indicating the air-fuel ratio obtained from the A / F sensor 308.

[0026] The turbocharger TC includes a compressor C, a turbine T, and a rotor shaft SH. The compressor C includes a compressor housing CH whose internal space also functions as part of the intake passage 220, and a compressor impeller CI housed in the compressor housing CH.

[0027] The compressor impeller CI is connected to the turbine impeller TI via the rotor shaft SH and rotates integrally with the turbine impeller TI. The compressor impeller CI rotates by the rotational power of the turbine impeller TI to compress the intake air.

[0028] The turbine T is composed of a turbine housing TH, whose internal space also functions as a part of the exhaust flow path 320, and a turbine impeller TI housed in the turbine housing TH. The turbine impeller TI is rotated by the exhaust gas discharged from the combustion chamber 118. The turbine impeller TI is rotated by the exhaust gas discharged from the combustion chamber 118, and the rotation of the turbine impeller TI rotates the compressor impeller CI, compressing the intake air, and supercharging is performed by the turbocharger TC.

[0029] The blow-by gas recirculation device 400 includes an oil separator 410 , a first piping structure 420 , a second piping structure 430 , and a third piping structure 440 .

[0030] The oil separator 410 is provided in the crankcase 104 and communicates with the crank chamber 120. Blow-by gas that has flowed out into the crank chamber 120 through a gap between the cylinder bore 112 and the piston 114 flows into the oil separator 410. The oil separator 410 separates the oil contained in the blow-by gas. In the first embodiment, the oil separator 410 includes a first oil separator 412 and a second oil separator 414.

[0031] The first piping structure 420 includes a first blow-by gas piping 422 and a first PCV valve 424. The first blow-by gas piping 422 connects the first oil separator 412 and the intake manifold 210.

[0032] A first blow-by gas passage 422a is formed inside the first blow-by gas piping 422. The first blow-by gas passage 422a communicates the crank chamber 120 with the intake passage 220 in the intake manifold 210 via the first oil separator 412. This allows the first blow-by gas passage 422a to return the blow-by gas from the crank chamber 120 to the intake passage 220. The first PCV valve 424 is provided in the first oil separator 412 and is connected to the first blow-by gas piping 422. The first PCV valve 424 prevents the backflow of intake air from the intake passage 220 to the first oil separator 412 via the first blow-by gas passage 422a. In addition, the first PCV valve 424 allows the flow of blow-by gas from the first oil separator 412 to the intake passage 220 via the first blow-by gas passage 422a.

[0033] The second piping structure 430 includes a second blow-by gas piping 432 and a second PCV valve 434. The second blow-by gas piping 432 communicates between the second oil separator 414 and a portion between the air cleaner 204 and the compressor C in the upstream intake pipe 202a.

[0034] A second blow-by gas passage 432a is formed inside the second blow-by gas piping 432. The second blow-by gas passage 432a communicates the crank chamber 120 with the intake passage 220 via the second oil separator 414. This allows the second blow-by gas passage 432a to return the blow-by gas from the crank chamber 120 to the intake passage 220. The second PCV valve 434 is provided in the second oil separator 414 and is connected to the second blow-by gas piping 432. The second PCV valve 434 prevents the backflow of intake air from the intake passage 220 to the second oil separator 414 via the second blow-by gas passage 432a. In addition, the second PCV valve 434 allows the flow of blow-by gas from the second oil separator 414 to the intake passage 220 via the second blow-by gas passage 432a.

[0035] The third piping structure 440 includes a third blow-by gas piping 442. The third blow-by gas piping 442 communicates between the locker chamber 132 and a portion of the downstream intake pipe 202b between the intercooler 206 and the throttle valve 208. A scavenging passage 442a is formed inside the third blow-by gas piping 442. In addition, a vent hole 444 is formed in the cylinder block 102 and the cylinder head 106 of the engine 100. The vent hole 444 communicates between the crank chamber 120 and the rocker chamber 132.

[0036] Here, when the turbocharger TC is not substantially supercharging and the throttle valve 208 is close to the closed state, the downstream side of the throttle valve 208 in the intake passage 220 becomes negative pressure, and the upstream side of the throttle valve 208 becomes close to atmospheric pressure. Therefore, the intake air is supplied to the crank chamber 120 via the scavenging passage 442a, the rocker chamber 132, and the air hole 444, and the blow-by gas in the crank chamber 120 is returned to the intake passage 220 via the first oil separator 412 and the first blow-by gas passage 422a.

[0037] On the other hand, when the turbocharger TC is supercharging, the upstream side of the compressor C becomes negative pressure, and the space between the compressor C and the throttle valve 208 becomes positive pressure. As a result, the intake air is supplied to the crank chamber 120 via the scavenging passage 442a, the rocker chamber 132, and the air hole 444, and the blow-by gas in the crank chamber 120 is returned to the intake passage 220 via the second oil separator 414 and the second blow-by gas passage 432a.

[0038] However, for example, if the first PCV valve 424 becomes detached from the first oil separator 412, blow-by gas will be released into the atmosphere, which will lead to air pollution. Therefore, it is required to provide the vehicle 10 with a mechanism for fixing the first PCV valve 424 and the second PCV valve 434 and a mechanism for quickly detecting that the first PCV valve 424 and the second PCV valve 434 have become detached.

[0039] However, for example, if first PCV valve 424 is fixed to first oil separator 412, when only first PCV valve 424 breaks down, the entire cylinder block 102 must be replaced, resulting in high replacement costs. Also, for example, if a dedicated detection device for detecting that first PCV valve 424 has come off is provided in order to quickly detect that first PCV valve 424 has come off, this requires the addition of a harness or circuit, which causes a problem of complicating the configuration of blow-by gas recirculation device 400. Therefore, here, the removal of the PCV valve is detected using an inexpensive and simple configuration.

[0040] Fig. 2 is a schematic diagram showing the configuration of the first piping structure 420 according to the first embodiment. The second piping structure 430 has a similar configuration to the first piping structure 420. Therefore, in Fig. 2, the configuration of the first piping structure 420 will be described in detail, and the detailed description of the configuration of the second piping structure 430 will be omitted.

[0041] 2, the first piping structure 420 of the first embodiment includes a first blow-by gas piping 422, a first PCV valve 424, and a boss 426. The first blow-by gas piping 422 has a main pipe 422b, a first branch pipe 422c, and a second branch pipe 422d.

[0042] The main pipe 422b is connected to the intake manifold 210. The first branch pipe 422c is one of the two branch pipes branched from the main pipe 422b. The first branch pipe 422c is connected to the first PCV valve 424 via a quick connector 424e. In the first embodiment, the first branch pipe 422c and the first PCV valve 424 are connected to each other by the quick connector 424e in an undetachable manner. Here, "undetachable" means that two members are fixed to each other and are not likely to come off due to an external force against a predetermined friction coefficient. On the other hand, "detachable" means that two members are not fixed to each other and are likely to come off due to an external force against a predetermined friction coefficient. Hereinafter, when an external force against a predetermined friction coefficient acts on two connected members, the two members are said to be removably connected. In addition, if two connected components cannot be separated when an external force acting against a predetermined coefficient of friction is applied, the two components are said to be irremovably connected.

[0043] Further, a first seal member 424f is provided between the first blow-by gas passage 422a formed inside the first branch pipe 422c and the first PCV valve 424. The first seal member 424f is, for example, an O-ring, and prevents the blow-by gas from leaking between the first blow-by gas passage 422a and the first PCV valve 424.

[0044] The second branch pipe 422d is the other branch pipe branched into two from the main pipe 422b. In the first embodiment, the main pipe 422b branches into two branch pipes, the first branch pipe 422c and the second branch pipe 422d, but the present invention is not limited to this, and the main pipe 422b may branch into three or more branch pipes. The second branch pipe 422d is detachably connected to the boss 426. The connection between the second branch pipe 422d and the boss 426 will be described in detail later.

[0045] Further, a second seal member 424g is provided between the second branch pipe 422d and the boss 426. The second seal member 424g is, for example, an O-ring, and suppresses leakage of blow-by gas from between the second branch pipe 422d and the boss 426. Therefore, in a state in which the first PCV valve 424 is connected to the first oil separator 412 and an end of the second branch pipe 422d is connected to the boss 426, the blow-by gas is returned to the intake manifold 210 without leaking into the atmosphere.

[0046] The first PCV valve 424 is removably attached to the outer surface OS of the first oil separator 412. On the other hand, the boss 426 is formed integrally with the outer surface OS of the first oil separator 412 and is formed non-removably on the outer surface OS. In the first embodiment, the first PCV valve 424 and the boss 426 are attached to the outer surface OS of the first oil separator 412, but it is sufficient that the first PCV valve 424 and the boss 426 are attached to the outer surface OS of the engine 100. Therefore, the first PCV valve 424 and the boss 426 may be attached to the outer surface OS of the engine 100 at a position different from that of the first oil separator 412.

[0047] The boss 426 has a recessed portion 426a into which the end portion in which the opening of the second branch pipe 422d is formed can be inserted and removed. The recessed portion 426a extends in a D1 direction perpendicular to the outer surface OS. The recessed portion 426a supports the end portion of the second branch pipe 422d so that the end portion can move in the D1 direction. In the first embodiment, the recessed portion 426a extends in the D1 direction perpendicular to the outer surface OS, but is not limited thereto, and the recessed portion 426a may extend in an intersecting direction other than the D1 direction perpendicular to the outer surface OS.

[0048] In the first embodiment, the main pipe 422b, the first branch pipe 422c, and the second branch pipe 422d are made of resin tubes integrally formed from resin. However, without being limited thereto, for example, the main pipe 422b of the first blow-by gas piping 422 may be made of a rubber hose, and the first branch pipe 422c and the second branch pipe 422d may be made of resin tubes integrally formed from resin. In other words, it is only necessary that at least the first branch pipe 422c and the second branch pipe 422d of the first blow-by gas piping 422 are integrally formed from resin, and the material of the main pipe 422b is not limited to resin.

[0049] Fig. 3 is a schematic diagram showing the configuration of the first piping structure 420 in a state in which the first PCV valve 424 is detached from the first oil separator 412. As shown in Fig. 3, the first PCV valve 424 moves in the direction D1 away from the outer surface OS due to the application of an external force against a predetermined friction coefficient, and is detached from the first oil separator 412. In addition, with the movement of the first PCV valve 424, the first branch pipe 422c also moves in the direction D1 away from the outer surface OS.

[0050] At this time, since the first branch pipe 422c and the second branch pipe 422d are integrally formed of resin, as shown in Fig. 3, the first branch pipe 422c and the second branch pipe 422d move together in the direction D1 away from the outer surface OS. Specifically, when the first PCV valve 424 is removed from the first oil separator 412, the first branch pipe 422c and the second branch pipe 422d move together while maintaining the relative positional relationship between the tip position P1 of the first branch pipe 422c and the tip position P2 of the second branch pipe 422d. The first blow-by gas piping 422 has a structural relationship in which the second branch pipe 422d always comes off from the boss 426 when the first branch pipe 422c comes off from the first oil separator 412. The first blow-by gas pipe 422 may be configured such that, when the first branch pipe 422c is about to come off from the first oil separator 412, the second branch pipe 422d comes off from the boss 426 first.

[0051] When the first branch pipe 422c and the second branch pipe 422d move together in the direction D1 away from the outer surface OS, the tip position P2 of the second branch pipe 422d moves from inside the recessed portion 426a of the boss 426 to outside the recessed portion 426a, and the end of the second branch pipe 422d is exposed to the outside space. When the end of the second branch pipe 422d is exposed to the outside space, the first blow-by gas passage 422a in the second branch pipe 422d communicates with the outside space, and the air is introduced into the first blow-by gas passage 422a.

[0052] 1 derives the air-fuel ratio based on a signal indicating the air-fuel ratio obtained from the A / F sensor 308, as described above. Here, if the first piping structure 420 does not have the second branch pipe 422d and the boss 426 and the first PCV valve 424 becomes detached from the first oil separator 412, it is difficult to detect the leakage of blow-by gas based on the output of the A / F sensor 308. This is because, for example, even if the intake manifold 210 becomes negative pressure and the air is introduced into the intake passage 220 via the first PCV valve 424, the first PCV valve 424 restricts the amount of air introduced, so that the amount of change in the output value of the A / F sensor 308 becomes small.

[0053] On the other hand, the first piping structure 420 of the first embodiment has a first branch pipe 422c that branches into two branches, a second branch pipe 422d, a first PCV valve 424 connected to the first branch pipe 422c, and a boss 426 that is detachably connected to the second branch pipe 422d. Therefore, when the first PCV valve 424 is removed from the first oil separator 412, the end of the second branch pipe 422d is removed from the recessed portion 426a of the boss 426, and the atmosphere can be introduced into the intake passage 220 via the second branch pipe 422d.

[0054] Unlike the first branch pipe 422c, the second branch pipe 422d is not provided with the first PCV valve 424, and therefore more air flows into the intake passage 220 than the first branch pipe 422c. As a result, when the first PCV valve 424 is disengaged from the first oil separator 412, the output value of the A / F sensor 308 changes by a predetermined value or more.

[0055] Therefore, detection device 310 can detect the dislocation of first PCV valve 424 and the leakage of blow-by gas based on the amount of change in the output value of A / F sensor 308. For example, when the amount of change in the output value of A / F sensor 308 is equal to or greater than a predetermined value, detection device 310 can detect the dislocation of first PCV valve 424 and the leakage of blow-by gas.

[0056] As described above, according to the first piping structure 420 of the first embodiment, when only the first PCV valve 424 breaks down, only the first PCV valve 424 can be replaced, and there is no need to provide a dedicated detection device for detecting that the first PCV valve 424 has been removed. Therefore, it is possible to detect that the first PCV valve 424 has been removed with an inexpensive and simple configuration.

[0057] 4 is a schematic diagram showing the configuration of the first piping structure 420A according to the second embodiment. Components substantially the same as those of the first piping structure 420 of the first embodiment are denoted by the same reference numerals and will not be described. The configuration of the first piping structure 420A of the second embodiment differs from the configuration of the first piping structure 420 of the first embodiment in that it has a connection member 500 provided in the first blow-by gas piping 422A.

[0058] As shown in FIG. 4, the first piping structure 420A of the second embodiment includes a first blow-by gas piping 422A, a first PCV valve 424, and a boss 426A. The first blow-by gas piping 422A has a main pipe 422b, a first branch pipe 422c, and a second branch pipe 422d. The boss 426A has a cylindrical shape that can be inserted into and removed from the first blow-by gas passage 422a (see FIG. 5) of the second branch pipe 422d. The boss 426A extends in a D1 direction perpendicular to the outer surface OS. The boss 426A also supports an end of the second branch pipe 422d so as to be movable in the D1 direction. In the second embodiment, the boss 426A extends in the D1 direction perpendicular to the outer surface OS, but is not limited thereto, and the boss 426A may extend in an intersecting direction other than the D1 direction perpendicular to the outer surface OS.

[0059] In the first blow-by gas piping 422A of the second embodiment, the main pipe 422b, the first branch pipe 422c, and the second branch pipe 422d are configured with rubber hoses. Therefore, the rigidity of the first blow-by gas piping 422A of the second embodiment is lower than the rigidity of the first blow-by gas piping 422 of the first embodiment.

[0060] Therefore, in the second embodiment, a connection member 500 is provided to connect a part of the first branch pipe 422c and a part of the second branch pipe 422d of the first blow-by gas pipe 422A. The connection member 500 is made of a material having higher rigidity than the first blow-by gas pipe 422A. The connection member 500 is made of, for example, resin or metal.

[0061] Fig. 5 is a schematic diagram showing the configuration of a connection member 500 according to the second embodiment. As shown in Fig. 5, the connection member 500 is composed of a flat first divided body 502 and a flat second divided body 504. A part of the first branch pipe 422c and a part of the second branch pipe 422d are sandwiched between the first divided body 502 and the second divided body 504, thereby being integrally connected and restricting relative movement therebetween.

[0062] Fig. 6 is a schematic diagram showing the configuration of the first piping structure 420A in a state in which the first PCV valve 424 is removed from the first oil separator 412. As shown in Fig. 6, the first PCV valve 424 moves in the direction D1 away from the outer surface OS and is removed from the first oil separator 412. In addition, with the movement of the first PCV valve 424, the first branch pipe 422c also moves in the direction D1 away from the outer surface OS.

[0063] At this time, since a part of the first branch pipe 422c and a part of the second branch pipe 422d are integrally formed by the connection member 500, as shown in Fig. 6, the first branch pipe 422c and the second branch pipe 422d move integrally in the direction D1 away from the outer surface OS. Specifically, when the first PCV valve 424 is removed from the first oil separator 412, the first branch pipe 422c and the second branch pipe 422d move integrally while maintaining the relative positional relationship between the tip position P1 of the first branch pipe 422c and the tip position P2 of the second branch pipe 422d. In other words, the connection member 500 of the second embodiment holds the first branch pipe 422c and the second branch pipe 422d integrally while maintaining the relative positional relationship between the tip position P1 of the first branch pipe 422c and the tip position P2 of the second branch pipe 422d. The first blow-by gas pipe 422 has a structural relationship such that when the first branch pipe 422c comes off the first oil separator 412, the second branch pipe 422d always comes off the boss 426.

[0064] When the first branch pipe 422c and the second branch pipe 422d move together in the direction D1 away from the outer surface OS, the tip position P2 of the second branch pipe 422d moves above the boss 426A, and the end of the second branch pipe 422d is exposed to the outside space. When the end of the second branch pipe 422d is exposed to the outside space, the first blow-by gas passage 422a in the second branch pipe 422d communicates with the outside space, and the air is introduced into the first blow-by gas passage 422a.

[0065] Therefore, similarly to the above-described first embodiment, according to the second embodiment, when only the first PCV valve 424 breaks down, only the first PCV valve 424 can be replaced, and there is no need to provide a dedicated detection device for detecting that the first PCV valve 424 has been removed. Therefore, similarly to the above-described first embodiment, it is possible to detect that the first PCV valve 424 has been removed with an inexpensive and simple configuration. Furthermore, according to the second embodiment, compared to the first embodiment, it is not necessary to integrally form the first branch pipe 422c and the second branch pipe 422d from resin, and therefore manufacturing costs can be kept low.

[0066] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can think of various modifications or alterations within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention. [Explanation of symbols]

[0067] TC Turbocharger 1 Engine System 10 Vehicles 100 Engine 200 Intake system 210 Intake manifold 300 Exhaust system 308 A / F sensor 310 Detection Device 400 Blow-by gas recirculation device 412 First Oil Separator 420, 420A First piping structure 422a First blow-by gas passage 422b master 422c First branch pipe 422d Second branch pipe 424 1st PCV valve 426, 426A Boss 500 Connection parts 502 1st division body 504 Second division body

Claims

1. A PCV valve attached to an outer surface of the engine; A boss formed on an outer surface of the engine and not removable; a blow-by gas pipe including a main pipe connected to an intake pipe, a first branch pipe branched from the main pipe and inseparably connected to the PCV valve, and a second branch pipe branched from the main pipe and removably connected to the boss; A blow-by gas recirculation device equipped with a blow-by gas recirculation device.

2. At least the first branch pipe and the second branch pipe of the blow-by gas piping are integrally formed of resin. The blow-by gas recirculation device according to claim 1.

3. a connecting member that connects a part of the first branch pipe and a part of the second branch pipe so as to maintain a relative positional relationship between a tip position of the first branch pipe and a tip position of the second branch pipe, The blow-by gas recirculation device according to claim 1.

4. The connection member is composed of a first divided body and a second divided body, A portion of the first branch pipe and a portion of the second branch pipe are connected by being sandwiched between the first division body and the second division body. The blow-by gas recirculation device according to claim 3.

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