Piping construction

Abstract

To maintain sealability in a fitting part while suppressing leakage of an odor component.SOLUTION: A piping structure includes: a hose which is made of a polymeric material and in which a circulation passage through which a blow-by gas circulates is formed; a PCV valve connected to the hose; and a cross-linking agent storage body disposed inside the PCV valve and storing a cross-linking agent flowing through the circulation passage when the blow-by gas flows.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a piping structure. [Background technology]

[0002] Conventionally, there is a piping structure that connects the crankcase and the intake pipe and includes a hose through which the blow-by gas flows in order to return the blow-by gas from inside the crankcase to the intake pipe. Patent Document 1 discloses that the inner surface of the hose through which the blow-by gas flows is formed of an amine cross-linked layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2012-529388 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the concentration of odorous components in blow-by gas increases, the odorous components may leak from the hose depending on the material of the hose. In this regard, if the inside of the hose is formed with an amine cross-linked layer, as in Patent Document 1, the leakage of odorous components can be suppressed. However, hoses cross-linked with a cross-linking agent are hard and have a large allowable bending radius, and when attached to a crankcase or intake pipe, they may not be able to maintain pressure resistance or sealing properties at the attachment point.

[0005] Therefore, an object of the present invention is to provide a piping structure that can maintain a tight seal at the attachment portion while suppressing the leakage of odorous components. [Means for solving the problem]

[0006] In order to solve the above problems, the piping structure of the present invention comprises: a hose made of a polymer material in which a flow passage for flowing blow-by gas is formed; a PCV valve connected to the hose; a cross-linking agent container disposed inside the PCV valve and containing a cross-linking agent that flows through the flow passage when the blow-by gas flows; Equipped with: [Effects of the Invention]

[0007] According to the present invention, it is possible to maintain a tight seal at the attachment portion while suppressing leakage of odorous components. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of an engine system according to this embodiment. [Figure 2] FIG. 2 is a diagram for explaining the configuration of the first PCV valve according to this embodiment. [Figure 3] FIG. 3 is a schematic diagram of the first hose after being crosslinked with a peroxide crosslinking agent. [Figure 4] FIG. 4 is a diagram for explaining the configuration of the first PCV valve according to this modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention and, unless otherwise specified, do not limit the present invention. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0010] 1 is a schematic diagram showing the configuration of an engine system 1 according to this embodiment. 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.

[0011] The engine 100 includes a cylinder block 102, a crankcase 104, a cylinder head 106, a head 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 the top of the cylinder block 102. The head cover 108 is connected to the top of the cylinder head 106. The cylinder head 106 is disposed between the cylinder block 102 and the head cover 108. The oil pan 110 is connected to the bottom of the crankcase 104.

[0012] A plurality of cylinder bores 112 are formed in the cylinder block 102, and a piston 114 is slidably supported in each of the cylinder bores 112 by a connecting rod 116. In the engine 100, the space surrounded by the cylinder bores 112, the cylinder head 106, and the crown surface of the piston 114 forms a combustion chamber 118.

[0013] In the engine 100, a space surrounded by the crankcase 104 and the oil pan 110 is formed 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.

[0014] 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.

[0015] In the engine 100, a space surrounded by the cylinder head 106 and the head cover 108 is formed as a cam chamber 132. An intake camshaft 134 and an exhaust camshaft 136 are rotatably supported in the cam chamber 132.

[0016] 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.

[0017] 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 passage between the exhaust port 126 and the combustion chamber 118.

[0018] 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 formed in the combustion chamber 118 is burned. This combustion causes the piston 114 to reciprocate, and this reciprocating motion is converted into the rotational motion of the crankshaft 122 via the connecting rod 116.

[0019] The intake system 200 includes an intake pipe 202, an air cleaner 204, a compressor C of the turbocharger TC, an intercooler 206, and a throttle valve 208. The intake pipe 202 includes an intake manifold and is connected to the upstream side of the intake port 124. An intake flow path 210 is formed inside the intake pipe 202. The intake flow path 210 communicates with the intake port 124.

[0020] An air cleaner 204, a compressor C of the turbocharger TC, an intercooler 206, and a throttle valve 208 are provided in this order from upstream to downstream in the intake pipe 202. The intake air purified by the air cleaner 204 is introduced into the combustion chamber 118 through an intake flow path 210 and the intake port 124. The intake pipe 202 is mainly 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.

[0021] The exhaust system 300 includes an exhaust pipe 302, a turbine T of the turbocharger TC, a catalyst 304, and a muffler 306. The exhaust pipe 302 includes an exhaust manifold and is connected to the downstream side of the exhaust port 126. An exhaust flow path 308 is formed inside the exhaust pipe 302. The exhaust flow path 308 communicates with the exhaust port 126.

[0022] A turbine T of a turbocharger TC, a catalyst 304, and a muffler 306 are provided in this order from upstream to downstream in the exhaust pipe 302. The exhaust gas generated in the combustion chamber 118 after combustion is purified by the catalyst 304 as it passes through an exhaust flow path 308, and is then discharged to the outside through the muffler 306.

[0023] The turbocharger TC includes a compressor C, a turbine T, and a rotor shaft SH. The compressor C is composed of a compressor housing CH, the internal space of which also functions as part of the intake air flow path 210, and a compressor impeller CI housed in the compressor housing CH.

[0024] 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 using the rotational power of the turbine impeller TI, compressing the intake air.

[0025] The turbine T is composed of a turbine housing TH, the interior space of which also functions as part of the exhaust flow path 308, and a turbine impeller TI housed within the turbine housing TH. The turbine impeller TI is rotated by the exhaust gas discharged from the combustion chamber 118.

[0026] 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.

[0027] The oil separator 410 is provided in the crankcase 104 and communicates with the crank chamber 120. The oil separator 410 separates oil mixed in from the blow-by gas that flows into the crank chamber 120 through the gap between the cylinder bore 112 and the piston 114. In this embodiment, the oil separator 410 includes a first oil separator 412 and a second oil separator 414.

[0028] The first piping structure 420 includes a first hose (hose) 422 and a first PCV valve 424. In this embodiment, the first hose 422 is a rubber hose. The first hose 422 connects the first oil separator 412 to a portion of the downstream intake pipe 202b between the intake port 124 and the throttle valve 208. Specifically, the first hose 422 connects the first oil separator 412 to the intake manifold.

[0029] A first blow-by gas flow passage (flow passage) 422a is formed inside the first hose 422. The first blow-by gas flow passage 422a connects the crank chamber 120 and the intake passage 210 via the first oil separator 412. The first blow-by gas flow passage 422a returns the blow-by gas to the intake passage 210. The first PCV valve 424 is provided in the first oil separator 412 and connected to the first hose 422 to prevent the intake air from flowing back from the intake passage 210 to the first oil separator 412.

[0030] The second piping structure 430 includes a second hose (hose) 432 and a second PCV valve 434. In this embodiment, the second hose 432 is a rubber hose. The second hose 432 connects the second oil separator 414 to a portion of the upstream intake pipe 202a between the air cleaner 204 and the compressor C.

[0031] A second blow-by gas flow passage (flow passage) 432a is formed inside the second hose 432. The second blow-by gas flow passage 432a connects the crank chamber 120 and the intake passage 210 via the second oil separator 414. The second blow-by gas flow passage 432a returns the blow-by gas to the intake passage 210. The second PCV valve 434 is provided in the second oil separator 414 and connected to the second hose 432 to prevent the intake air from flowing back from the intake passage 210 to the second oil separator 414.

[0032] The third piping structure 440 includes a third hose 442. The third hose 442 communicates between the cam chamber 132 and the downstream intake pipe 202b between the intercooler 206 and the throttle valve 208. A scavenging passage 442a is formed inside the third hose 442. In addition, an air vent 444 is formed in the cylinder block 102 and the cylinder head 106 of the engine 100. The air vent 444 communicates between the crank chamber 120 and the cam chamber 132.

[0033] When the turbocharger TC is not substantially performing turbocharging, negative pressure is created downstream of the throttle valve 208 in the intake passage 210. As a result, intake air is supplied to the crank chamber 120 via the scavenging passage 442a, the cam chamber 132, and the vent hole 444, and blow-by gas in the crank chamber 120 is returned to the intake passage 210 via the first oil separator 412 and the first blow-by gas flow passage 422a.

[0034] On the other hand, when the turbocharger TC is performing turbocharging, negative pressure is created upstream of the compressor C. As a result, intake air is supplied to the crank chamber 120 via the scavenging passage 442a, the cam chamber 132, and the ventilation hole 444, and blow-by gas in the crank chamber 120 is returned to the intake passage 210 via the second oil separator 414 and the second blow-by gas flow passage 432a.

[0035] Incidentally, when the concentration of odorous components such as naphthalene and its derivatives, which are unburned fuel products, in the blow-by gas increases, the odorous components may leak from the hoses that carry the blow-by gas, depending on the material of the hoses.

[0036] Therefore, in this embodiment, the inside of first hose 422 and second hose 432, which allow blow-by gas to flow, is cross-linked with a cross-linking agent to form a cross-linked layer. However, hoses cross-linked with a cross-linking agent are hard, and when attached to a crankcase or an intake pipe, they may not be able to maintain pressure resistance at the attachment point.

[0037] Therefore, in this embodiment, the first hose 422 and the second hose 432 before being cross-linked with a cross-linking agent are attached to the first PCV valve 424 and the second PCV valve 434. Furthermore, a cross-linking agent container 450 (see FIG. 2) containing a cross-linking agent is provided inside the first PCV valve 424 and the second PCV valve 434.

[0038] 2 is a diagram for explaining the configuration of the first PCV valve 424 according to this embodiment. Note that the configuration of the second PCV valve 434 is the same as the configuration of the first PCV valve 424, so a description thereof will be omitted, and the configuration of the first PCV valve 424 will be explained in detail below.

[0039] As shown in FIG. 2, the first PCV valve 424 includes a housing 424 a, a movable valve 424 b, a spring 424 c, and a cross-linking agent container 450 .

[0040] The housing 424a is attached to the first oil separator 412 and houses the movable valve 424b, the spring 424c, and the cross-linking agent container 450. The housing 424a has an inlet O1 for blow-by gas and an outlet O2 for blow-by gas. The blow-by gas that has flowed through the first oil separator 412 is introduced into the inlet O1. The outlet O2 causes the blow-by gas introduced from the inlet O1 to flow out to the first hose 422. In this way, the housing 424a causes the blow-by gas to flow from the inlet O1 toward the outlet O2.

[0041] The movable valve 424b is provided inside the housing 424a, and moves from the inlet O1 to the outlet O2 when blow-by gas flows from the inlet O1 to the outlet O2. Furthermore, when blow-by gas or intake air flows from the outlet O2 to the inlet O1, the movable valve 424b moves from the outlet O2 to the inlet O1 and closes the inlet O1. In this way, the movable valve 424b is movable inside the housing 424a, and functions as a check valve that allows the flow of fluid from the inlet O1 to the outlet O2 and restricts the flow of fluid from the outlet O2 to the inlet O1.

[0042] The spring 424c is disposed between the housing 424a and the movable valve 424b and biases the movable valve 424b from the outlet O2 toward the inlet O1. The biasing force of the spring 424c is smaller than the pressure pressing on the movable valve 424b when the blow-by gas flows from the inlet O1 toward the outlet O2. Therefore, the movable valve 424b can move from the inlet O1 toward the outlet O2 when the blow-by gas flows from the inlet O1 toward the outlet O2. Furthermore, when the biasing force of the spring 424c is larger than the pressing force of the blow-by gas from the inlet O1 toward the outlet O2, the movable valve 424b moves from the outlet O2 toward the inlet O1 and closes the inlet O1.

[0043] The crosslinking agent container 450 is a bag provided inside the housing 424a and contains a crosslinking agent. The crosslinking agent container 450 is located closer to the outlet O2 than the movable valve 424b in the housing 424a and within the movable range of the movable valve 424b. In other words, the movable valve 424b is disposed at a position where it contacts at least a portion of the crosslinking agent container 450. Therefore, when the movable valve 424b moves toward the outlet O2, that is, when the blow-by gas flows from the inlet O1 toward the outlet O2, the crosslinking agent container 450 collides with the tip of the movable valve 424b. At least a portion of the crosslinking agent container 450 is damaged when it collides with the tip of the movable valve 424b, and the crosslinking agent contained in the crosslinking agent container 450 is released into the first blow-by gas flow passage 422a together with the blow-by gas. In other words, the movable valve 424b breaks at least a part of the cross-linking agent container 450 when the blow-by gas flows from the inlet O1 toward the outlet O2.

[0044] However, the cross-linking agent container 450 does not have to be disposed within the movable range of the movable valve 424b of the housing 424a. In this case, at least a part of the cross-linking agent container 450 may be damaged by the heat of the blow-by gas.

[0045] In this embodiment, the crosslinking agent is an organic peroxide crosslinking agent (hereinafter simply referred to as a peroxide crosslinking agent). Specific examples of peroxide crosslinking agents include diacyl peroxides, alkyl peroxy esters, peroxydicarbonates, peroxycarbonates, peroxyketals, dialkyl peroxides, and hydroperoxides. However, the crosslinking agent is not limited thereto, and may include crosslinking agents other than peroxide crosslinking agents, such as diamine crosslinking agents, sodium chloride, organic ammonium, zinc dithiocarbamate, ammonium salts, triazine, bisphenol AF, and triallyl isocyanate.

[0046] In this embodiment, the first hose 422 and the second hose 432 are made of polymeric materials, including, for example, diene rubber and non-diene rubber. Specifically, diene rubbers include styrene-butadiene rubber (SBR), isoprene rubber (IR), butadiene rubber (BR), chloroprene rubber (CR), and acrylonitrile-butadiene rubber (NBR). Non-diene rubbers include natural rubber (NR), butyl rubber (IIR), ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), silicone rubber (MQ), fluororubber (FKM), and epichlorohydrin rubber (ECO). However, without being limited thereto, the first hose 422 and the second hose 432 may include, for example, urethane, epoxy resin, acrylic, fluororubber, and fluororesin.

[0047] In this embodiment, first hose 422 and second hose 432 are made of rubber, and unreacted monomers from manufacturing remain inside or on the surface of the rubber. When a cross-linking agent flows from first PCV valve 424 and second PCV valve 434 along with the blow-by gas, the cross-linking agent reacts with the residual monomers in first hose 422 and second hose 432, forming a new cross-linked layer on the inner surface of the hose. The cross-linked layer is, for example, a layer made of a resin film.

[0048] The crosslinking reaction is, for example, the reaction shown in the following chemical formula 1. As shown in the following chemical formula 1, in the crosslinking reaction, the crosslinking agent decomposes due to the heat of the blow-by gas to generate radicals. These radicals then abstract hydrogen from the main chains of the monomers on the inner surfaces of first hose 422 and second hose 432, and the main chains of the monomers from which hydrogen has been abstracted are bonded together. [ka]

[0049] Here, the temperature of the blow-by gas flowing inside the first hose 422 and the second hose 432 is approximately 130°C to 150°C. Therefore, if the 10-hour half-life temperature (reaction temperature) of a cross-linking agent is equal to or lower than the blow-by gas temperature, it can be used as a cross-linking agent for cross-linking the inner surfaces of the first hose 422 and the second hose 432. However, a lower reaction temperature range, i.e., a lower 10-hour half-life temperature range, is preferable because it allows the inner surfaces of the first hose 422 and the second hose 432 to be cross-linked more quickly. Therefore, of the above-mentioned peroxide cross-linking agents, it is preferable to use diacyl peroxides, alkyl peroxy esters, peroxydicarbonates, peroxycarbonates, and peroxyketals rather than dialkyl peroxides and hydroperoxides.

[0050] Although the crosslinking reaction includes vulcanization using sulfur, in this embodiment, by using a peroxide crosslinking agent, crosslinking can be performed on non-diene rubber that is difficult to vulcanize or does not vulcanize. Furthermore, by performing crosslinking using a peroxide crosslinking agent instead of vulcanization using sulfur, a crosslinked layer with better heat resistance and chemical resistance can be formed on the inner surface of first hose 422 and second hose 432.

[0051] 3 is a schematic diagram of first hose 422 after cross-linking with a peroxide cross-linking agent. Note that the configuration of second hose 432 is the same as that of first hose 422, so a description thereof will be omitted, and the configuration of first hose 422 will be described in detail below.

[0052] 3, the first hose 422 includes a first rubber layer (first polymer material layer) 422b, a second rubber layer (second polymer material layer) 422c, an attachment portion 422d, and a non-attachment portion 422e. The first rubber layer 422b is, for example, a layer made of the diene rubber or non-diene rubber described above, and is a layer in which unreacted monomers remain inside. The second rubber layer 422c is provided on the inside of the first hose 422 relative to the first rubber layer 422b, and is a layer composed of a cross-linked material layer formed by the reaction of the unreacted residual monomers with a cross-linking agent.

[0053] The attachment portion 422d is a portion of the first hose 422 into which the first PCV valve 424 can enter. As shown in FIG. 3, with the first PCV valve 424 inserted inside the first hose 422, the first hose 422 is attached to the first PCV valve 424 by an attachment tool (not shown). With the first hose 422 attached to the first PCV valve 424, the portion into which the first PCV valve 424 enters is the attachment portion 422d. In other words, the attachment portion 422d is a portion of the first hose 422 closer to the inlet O1 (see FIG. 2) side or the crank chamber 120 (see FIG. 1) side than the outlet O2 of the first PCV valve 424. The attachment portion 422d is formed only by the first rubber layer 422b and does not include the second rubber layer 422c.

[0054] The non-attachment portion 422e is a portion of the first hose 422 other than the attachment portion 422d. In other words, the non-attachment portion 422e is a portion of the first hose 422 on the opposite side of the inlet O1 with respect to the outlet O2 of the first PCV valve 424, or on the intake flow path 210 (see FIG. 1) side. The non-attachment portion 422e is made up of the first rubber layer 422b and the second rubber layer 422c formed inside the first rubber layer 422b.

[0055] In this way, since the inside of the mounting portion 422d is not cross-linked with a cross-linking agent, it is possible to improve the sealing performance when the mounting portion 422d is attached to the first PCV valve 424, compared to when the inside of the mounting portion 422d is cross-linked. On the other hand, since the inside of the non-mounting portion 422e is cross-linked with a cross-linking agent, it is possible to suppress leakage of odorous components when blow-by gas flows, and improve pressure resistance, compared to when the inside of the mounting portion 422d is not cross-linked.

[0056] As described above, the first PCV valve 424 and the second PCV valve 434 of this embodiment each have a crosslinking agent container 450 disposed therein. The crosslinking agent container 450 is broken when blow-by gas flows through the first PCV valve 424 and the second PCV valve 434, and the crosslinking agent contained therein flows through the first hose 422 and the second hose 432 together with the blow-by gas. As a result, a crosslinked material layer is formed on the inside of the first hose 422 and the second hose 432, and the crosslinked material layer enhances resistance to naphthalene and its derivatives, thereby suppressing leakage of odorous components. Furthermore, the crosslinking agent container 450 in the first PCV valve 424 and the second PCV valve 434 is broken by the blow-by gas after the first hose 422 and the second hose 432 are attached, releasing the crosslinking agent, thereby maintaining pressure resistance at the attachment portion 422d.

[0057] Furthermore, the first PCV valve 424 and the second PCV valve 434 are equipped with movable valves 424b that are actuated when blow-by gas flows. The cross-linking agent container 450 collides with the tip of the movable valve 424b when the movable valve 424b is actuated. Therefore, the cross-linking agent container 450 can be reliably damaged when the blow-by gas flows, and the cross-linking agent can be supplied to the first blow-by gas flow passage 422a and the second blow-by gas flow passage 432a together with the blow-by gas. The tip of the movable valve 424b may have an acute-angled shape. The acute-angled shape of the tip of the movable valve 424b makes it easier to damage the cross-linking agent container 450.

[0058] (Variation) 4 is a diagram illustrating the configuration of a first PCV valve 1424 according to this modified example. Components that are substantially the same as those in the above embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted. As shown in FIG. 4, the first PCV valve 1424 includes a housing 424a, a movable valve 424b, a spring 424c, and a cross-linking agent container 1450.

[0059] The crosslinking agent container 1450 is a bag provided inside the housing 424a and contains a crosslinking agent and an additive for the crosslinking agent. The crosslinking agent container 1450 is located closer to the outlet O2 than the movable valve 424b in the housing 424a and is also located within the movable range of the movable valve 424b. Therefore, when the movable valve 424b moves toward the outlet O2, that is, when the blow-by gas flows from the inlet O1 toward the outlet O2, the crosslinking agent container 1450 collides with the tip of the movable valve 424b. At least a portion of the crosslinking agent container 1450 is damaged when it collides with the tip of the movable valve 424b, and the crosslinking agent and additive contained inside the crosslinking agent container 1450 flow through the first blow-by gas flow passage 422a together with the blow-by gas. In other words, the movable valve 424b breaks at least a part of the cross-linking agent container 1450 when the blow-by gas flows from the inlet O1 toward the outlet O2.

[0060] However, the cross-linking agent container 1450 does not have to be disposed within the movable range of the movable valve 424b of the housing 424a. In this case, at least a part of the cross-linking agent container 1450 may be damaged by the heat of the blow-by gas.

[0061] Examples of crosslinking agents and additives in this modification are described below. When the first hose 422 and the second hose 432 are made of urethane, the crosslinking agent is a diamine-based crosslinking agent, and the additives are a polyol-based additive and an isocyanate-based additive. When the first hose 422 and the second hose 432 are made of epoxy resin, the crosslinking agent is sodium chloride, and the additives are a bisphenol-based additive and epichlorohydrin. When the first hose 422 and the second hose 432 are made of acrylic, the crosslinking agent is organic ammonium, zinc dithiocarbamate, ammonium salt, triazine, or a diamine-based crosslinking agent, and the additives are an acrylic acid monomer and ammonium persulfate. When the first hose 422 and the second hose 432 are made of fluorine-based rubber or fluorine-based resin, the crosslinking agent is a diamine-based crosslinking agent, bisphenol AF, and triallyl isocyanate, and the additives are vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene, and perfluoromethyl vinyl ether.

[0062] As in this modified example, the cross-linking agent container 1450 contains a cross-linking agent and an additive for the cross-linking agent, and thus the heat resistance, cold resistance, chemical resistance, gas permeability, etc. of the first hose 422 and the second hose 432 can be improved compared to the above embodiment.

[0063] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present invention.

[0064] In the above embodiment and modified example, an example has been described in which the inner surfaces of first hose 422 and second hose 432 are directly cross-linked. However, the present invention is not limited to this, and a base resin such as an epoxy resin may be applied to the inner surfaces of first hose 422 and second hose 432, and a cross-linking agent serving as a curing agent for the epoxy resin may be contained in cross-linking agent containers 450 and 1450. In this case, when the cross-linking agent flows together with the blow-by gas, the epoxy resin hardens, and a resin film is formed on the inner surfaces of first hose 422 and second hose 432 as a cross-linked material layer. [Explanation of symbols]

[0065] O1 inlet O2 outlet 400 Blow-by gas recirculation device 410 Oil Separator 412 First oil separator 414 Second oil separator 420 1st piping structure 422 No. 1 Hose (Hose) 422a First blow-by gas passage (passage) 422b First rubber layer 422c Second rubber layer (cross-linked layer) 422d Mounting part 422e Non-mounting part 424 First PCV valve (PCV valve) 424a housing 424b Movable valve 424c spring 430 2nd piping structure 432 Second Hose (Hose) 432a Second blow-by gas passage (passage) 434 Second PCV valve (PCV valve) 450 Crosslinking agent container 1424 First PCV valve (PCV valve) 1450 Crosslinking agent container

Claims

1. a hose made of a polymer material in which a flow passage for flowing blow-by gas is formed; a PCV valve connected to the hose; a cross-linking agent container disposed inside the PCV valve and containing a cross-linking agent that flows through the flow passage when the blow-by gas flows; A piping structure equipped with:

2. a movable valve provided in the PCV valve and actuated when the blow-by gas flows; the movable valve is disposed at a position where it contacts at least a part of the crosslinking agent container; The piping structure according to claim 1 .

3. The crosslinking agent is a peroxide crosslinking agent. The piping structure according to claim 1 or 2.

4. the crosslinking agent container contains an additive for the crosslinking agent; The piping structure according to any one of claims 1 to 3.

5. a mounting portion of the hose for the PCV valve is formed by a first rubber layer; a non-attachment portion of the hose other than the attachment portion is formed by the first rubber layer and a second rubber layer formed inside the first rubber layer; The piping structure according to any one of claims 1 to 4.

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