JP2020148099A - Oil separation device - Google Patents

Abstract

To reduce an outflow amount of oil mist.SOLUTION: An oil separation device 402 includes a body 404 which is disposed between a plurality of intake branches 312 connecting an intake port of an engine and an intake collector 310 of an intake manifold 308 disposed at a vertical upper side of the engine, a blow-by gas flow passage 406 which is formed inside the body 404 so that blow-by gas passes therethrough, and a collision plate 408 which is arranged in the blow-by gas flow passage 406. Accordingly, the oil separation device 402 can reduce an outflow amount of oil mist while efficiently using a dead space.SELECTED DRAWING: Figure 2

Description

The present invention relates to an oil separator.

The engine burns a mixture of fuel and air in a cylinder (combustion chamber). The burned combustion gas and the unburned air-fuel mixture leak into the crankcase as blow-by gas through the gap between the cylinder and the piston. The blow-by gas contains engine oil (hereinafter referred to as oil mist) atomized by the crankcase.

Patent Document 1 discloses an oil separating device that separates oil mist contained in blow-by gas.

Japanese Unexamined Patent Publication No. 2004-52578

In Patent Document 1, the oil separating device is embedded in the cylinder head cover of the engine. The height of the engine oil level in the cylinder head cover varies depending on the running condition of the vehicle equipped with the engine. Therefore, depending on the running condition of the vehicle, the oil separating device may be close to the oil level of the engine oil.

When the oil separator is close to the oil level of the engine oil, oil mist easily flows into the inside. As a result, the oil separator has a problem that the oil mist cannot be completely collected inside and the outflow amount of the oil mist increases.

Therefore, an object of the present invention is to provide an oil separation device capable of reducing the outflow amount of oil mist.

In order to solve the above problems, the oil separator of the present invention is arranged between a plurality of intake branches connecting the intake port of the engine and the intake collector of the intake manifold arranged vertically above the engine. It is provided with a main body, a blow-by gas flow path formed inside the main body and capable of flowing blow-by gas, and a collision plate arranged in the blow-by gas flow path.

The intake branch has a curved portion, and the main body has a constricted portion arranged between a plurality of intake branches and an expansion portion continuous with the narrowed portion and arranged vertically above the curved portion. In the cross section of the blow-by gas flow path perpendicular to the flow direction in which the blow-by gas flows, the flow path cross section of the expansion portion may be larger than the flow path cross section of the narrowed portion.

A plurality of collision plates are arranged in the blow-by gas flow path, and the blow-by gas flow path is a valve on the downstream side with respect to the collision plate arranged on the most downstream side in the flow direction in which the blow-by gas flows. May be arranged.

The main body may be integrally formed with the intake manifold.

According to the present invention, the outflow amount of oil mist can be reduced.

FIG. 1 is a schematic diagram illustrating a configuration of an engine system. FIG. 2 is a schematic view illustrating the configuration of the oil separation device. FIG. 3 is a cross-sectional view taken along the line III-III shown in FIG. FIG. 4 is an extracted view of the alternate long and short dash line portion shown in FIG.

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 numerical values shown in such an embodiment are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are designated by the same reference numerals to omit duplicate description, and elements not directly related to the present invention are not shown. To do.

FIG. 1 is a schematic view illustrating the configuration of the engine system 100. FIG. 1 shows a view of the engine system 100 as viewed from the front side. As shown in FIG. 1, the engine system 100 includes an engine 200 and an intake system 300. The engine system 100 is mounted on a vehicle, for example.

The engine 200 includes two cylinder blocks 202a, 202b, two cylinder heads 204a, 204b, two carriers 206a, 206b, two rocker covers 208a, 208b, and two crankcases 210a, 210b. It is composed.

The engine 200 has a rocker cover 208a, a carrier 206a, a cylinder head 204a, a cylinder block 202a, a crankcase 210a, a crankcase 210b, a cylinder block 202b, a cylinder head 204b, a carrier 206b, and a rocker from the right side to the left side in FIG. The covers 208b are arranged side by side in the horizontal direction (left-right direction in FIG. 1).

In the engine 200, a plurality of cylinders (not shown) formed inside the cylinder blocks 202a and 202b and pistons (not shown) arranged inside each cylinder are horizontally opposed to each other with the crankshaft 220 described later interposed therebetween. It is a horizontally opposed engine to be arranged. In the present embodiment, two cylinders (that is, a total of four cylinders) are formed in the cylinder blocks 202a and 202b, respectively.

In the present embodiment, the crankcase 210a is integrally formed with the cylinder block 202a, and the crankcase 210b is integrally formed with the cylinder block 202b. However, the crankcases 210a and 210b may be formed separately from the cylinder blocks 202a and 202b.

A chain cover 212 is joined to the front side (front side in FIG. 1) of the cylinder blocks 202a, 202b, cylinder heads 204a, 204b, carriers 206a, 206b, rocker covers 208a, 208b, and crankcases 210a, 210b. .. The chain cover 212 covers the front side of the cylinder blocks 202a and 202b, the cylinder heads 204a and 204b, the carriers 206a and 206b, the rocker covers 208a and 208b, and the crankcases 210a and 210b.

A space surrounded by the front surfaces of the cylinder blocks 202a and 202b, the cylinder heads 204a and 204b, the carriers 206a and 206b, the rocker covers 208a and 208b, the crankcases 210a and 210b, and the chain cover 212 is formed as the chain chamber 214.

A space surrounded by the cylinder head 204a and the rocker cover 208a is formed as the rocker chamber 216a. A space surrounded by the cylinder head 204b and the rocker cover 208b is formed as the rocker chamber 216b. Further, the internal space of the two crankcases 210a and 210b (that is, the space surrounded by the two crankcases 210a and 210b) is formed as the crankcase 218.

An intake port IP and an exhaust port (not shown) are formed in the cylinder heads 204a and 204b. One end of the intake port IP opens to the upper surface (upper side in FIG. 1) of the cylinder heads 204a and 204b, and the other end is connected to the combustion chamber (not shown) of the engine 200. One end of the exhaust port opens to the lower surface (lower side in FIG. 1) of the cylinder heads 204a and 204b, and the other end is connected to the combustion chamber of the engine 200. An intake valve (not shown) is arranged in the intake port IP, and an exhaust valve (not shown) is arranged in the exhaust valve.

In the present embodiment, the cylinder heads 204a and 204b are formed with a plurality of intake port IPs and a plurality of exhaust ports, respectively. Specifically, the cylinder heads 204a and 204b are formed with two intake port IPs and two exhaust ports, respectively.

The carrier 206a has an intake camshaft 222a to which a cam for moving an intake valve for opening and closing the intake port IP is fixed, and an exhaust cam shaft for moving an exhaust valve for opening and closing the exhaust port. The camshaft 224a is rotatably supported. Similarly, the carrier 206b is rotatably supported by the intake camshaft 222b and the exhaust camshaft 224b.

A crankshaft 220 is rotatably supported between the two cylinder blocks 202a and 202b. Although detailed description will be omitted, pistons connected to the crankshaft 220 via a connecting rod (not shown) are slidably arranged in each of the cylinders in the cylinder blocks 202a and 202b so as to be slidable in the horizontal direction. ing. The crankshaft 220 is rotationally driven by the reciprocating movement of the piston.

In the chain chamber 214, cam sprockets 226a and 226b provided at one end of the intake camshaft 222a and 222b, and cam sprockets 228a and 228b provided at one end of the exhaust camshaft 224a and 224b are arranged.

In the chain chamber 214, a drive sprocket 230 provided at one end of the crankshaft 220 is arranged. A timing chain 232a is hung on the drive sprocket 230, the cam sprocket 226a, and the cam sprocket 228a. Further, a timing chain 232b is hung on the driving sprocket 230, the cam sprocket 226b, and the cam sprocket 228b.

As a result, when the crankshaft 220 rotates, the intake camshaft 222a and the exhaust camshaft 224a are rotationally driven via the timing chain 232a. Further, when the crankshaft 220 rotates, the intake camshaft 222b and the exhaust camshaft 224b are rotationally driven via the timing chain 232b. In the present embodiment, the crankshaft 220 is rotationally driven clockwise in FIG. 1, and the timing chains 232a and 232b move clockwise as the crankshaft 220 rotates.

An oil pan 234 is provided vertically below the cylinder blocks 202a and 202b and the crankcases 210a and 210b. Engine oil is stored in the oil pan 234. An oil pump (not shown) is connected to the oil pan 234, sucks the engine oil stored in the oil pan 234, and supplies the sucked engine oil to each part of the engine 200.

The intake system 300 includes an intake pipe 302, an air cleaner 304, and a throttle valve 306. The intake pipe 302 is connected to the intake port IP of the engine 200.

An air cleaner 304 and a throttle valve 306 are arranged in the intake pipe 302 in order from the side (upstream side) separated from the engine 200. The air cleaner 304 removes foreign matter mixed with the air (intake air) taken in from the outside of the engine system 100. The throttle valve 306 is opened and closed by an actuator (not shown) according to the opening degree of the accelerator (not shown) of the vehicle, and adjusts the amount of intake air delivered to the engine 200.

The intake pipe 302 includes an intake manifold 308. The intake manifold 308 is arranged at a position closest to the engine 200 in the intake pipe 302. The intake manifold 308 is arranged vertically above the engine 200 (upper side in FIG. 1). The intake manifold 308 is connected to the intake port IP of the engine 200.

The intake manifold 308 is composed of, for example, a resin injection molded product. The intake manifold 308 includes an upper split body 308a made of resin and a lower split body 308 b. The intake manifold 308 is integrally formed by crimping (welding) the upper split body 308a and the lower split body 308b.

The intake manifold 308 includes a substantially box-shaped intake collector 310 and a plurality of intake branches 312. The intake collector 310 is configured as an assembly unit in which a plurality of intake branches 312 are assembled. The intake collector 310 distributes the air that has passed through the throttle valve 306 to each intake branch 312.

The plurality of intake branches 312 are formed in the same number as the intake port IPs (or cylinders). Therefore, in the present embodiment, the intake manifold 308 is formed with four intake branches 312. Two intake branches 312 are arranged in the horizontal direction (left-right direction in FIG. 1) with the intake collector 310 in between.

One end of the intake branch 312 is connected to the intake collector 310, and the other end is connected to the intake port IP of the engine 200. In this way, the intake branch 312 is configured as a connecting tube that connects the intake port IP of the engine 200 and the intake collector 310 of the intake manifold 308. The intake branch 312 extends horizontally (left-right direction in FIG. 1) from the intake collector 310 toward the engine 200, and is formed so as to be curved vertically downward (downward in FIG. 1) from the middle. Has been done. As shown in FIG. 1, the intake branch 312 is formed with a curved portion 312a.

In the intake manifold 308 (intake pipe 302), an intake flow path for passing intake (air) is formed inside. The intake flow path is connected to the intake port IP of the engine 200. The intake manifold 308 (intake pipe 302) supplies air to the engine 200.

The intake port IP introduces the air supplied from the intake manifold 308 into the combustion chamber (cylinder) of the engine 200. The engine 200 burns a mixture of fuel and air in a combustion chamber (cylinder). The burned combustion gas and the unburned air-fuel mixture leak into the crankcases 210a and 210b as blow-by gas from the gap between the cylinder and the piston.

Here, the crankcases 210a and 210b contain oil mist obtained by atomizing the engine oil stored in the oil pan 234. Therefore, the blow-by gas leaked into the crankcases 210a and 210b contains oil mist.

Blow-by gas contains harmful substances (eg, carbon monoxide (CO)) and, when released into the atmosphere, leads to air pollution. Therefore, the engine system 100 is provided with a blow-by gas recirculation system 400 that recirculates the blow-by gas leaked to the crankcases 210a and 210b to the intake pipe 302 (intake flow path).

However, as described above, the blow-by gas contains oil mist. Therefore, when the blow-by gas is returned to the intake flow path, the engine 200 burns the oil mist contained in the blow-by gas. When the oil mist is burned, the engine oil decreases, leading to an increase in oil consumption. Further, when the oil mist is burned, sludge (carbon) is deposited in the vicinity of the combustion chamber of the engine 200. When sludge accumulates, the fuel efficiency of the vehicle deteriorates and the engine 200 burns.

Therefore, the blow-by gas recirculation system 400 is provided with an oil separation device 402 that separates and removes the oil mist contained in the blow-by gas.

Conventionally, the oil separator has been arranged inside the engine. When the oil separator is placed inside the engine, it may be close to the oil level of the engine oil stored in the oil pan. For example, the height of the oil level of the engine oil varies depending on the running state of the vehicle equipped with the engine. Therefore, depending on the running condition of the vehicle, the oil separating device may be close to the oil level of the engine oil.

When the oil separator is close to the oil level of the engine oil, oil mist easily flows into the inside. As a result, the oil separation device may not be able to collect the oil mist inside, and the outflow amount of the oil mist may increase. When the outflow amount of the oil mist flowing out from the oil separation device increases, as described above, it leads to an increase in the consumption amount of engine oil, deterioration of fuel consumption, seizure of the engine 200, and the like.

Therefore, in the present embodiment, the oil separation device 402 is arranged outside the engine 200 and is arranged at a position vertically above the engine 200. Specifically, the oil separation device 402 is provided on the intake branch 312 of the intake manifold 308.

FIG. 2 is a schematic view illustrating the configuration of the oil separation device 402. FIG. 3 is a cross-sectional view taken along the line III-III shown in FIG. In FIG. 2, the intake manifold 308 is shown by a broken line and the oil separator 402 is shown by a solid line for the sake of clarity. In addition, the distribution direction (traveling direction) in which blow-by gas flows is indicated by a white arrow.

As shown in FIG. 2, a pair of intake branches 312 of the intake manifold 308 are provided in the left-right direction (both sides) of the intake collector 310. Similar to the intake branch 312, a pair of oil separation devices 402 are provided in the left-right direction (both sides) of the intake collector 310.

The oil separation device 402 includes an upstream side connecting pipe UC, a main body 404, and a downstream side connecting pipe DC. The upstream side connecting pipe UC, the main body 404, and the downstream side connecting pipe DC are made of, for example, an injection molded product made of resin. In the present embodiment, the upstream side connecting pipe UC, the main body 404, and the downstream side connecting pipe DC are integrally formed with the intake manifold 308 (specifically, the upper split body 308a). However, the upstream side connecting pipe UC, the main body 404, and the downstream side connecting pipe DC may be formed separately.

One end of the upstream connection pipe UC is connected to the crankcases 210a and 210b (see FIG. 1), and the other end is connected to the main body 404. Blow-by gas in the crankcases 210a and 210b is introduced into the upstream connecting pipe UC. The upstream connection pipe UC guides the blow-by gas introduced inside to the main body 404.

FIG. 4 is an extracted view of the alternate long and short dash line portion shown in FIG. As shown in FIG. 4, the upstream connecting pipe UC is inserted into the opening O of the crankcase 210b. The upstream side connecting pipe UC includes a flange portion FL and a seal ring SL. The flange portion FL is arranged on the upper surface (upper side in FIG. 4) of the crankcase 210b and covers the opening O of the crankcase 210b over the entire circumference. The seal ring SL is arranged between the inner peripheral surface of the opening O of the crankcase 210b and the outer peripheral surface of the upstream connecting pipe UC. The seal ring SL suppresses blow-by gas in the crankcase 218 from leaking to the outside of the engine 200 through the opening O of the crankcase 210b. As described above, the upstream side connecting pipe UC of the present embodiment is configured by a shaft seal structure integrally formed with the main body 404. As a result, the oil separator 402 eliminates the need for parts such as hoses and hose clamps that have been conventionally used, and the cost can be reduced.

Returning to FIG. 2, one end of the downstream connecting pipe DC is connected to the main body 404, and the other end is connected to the intake pipe 302. Further, a PCV valve PV is arranged in the downstream connection pipe DC. In the present embodiment, the downstream connecting pipe DC on the left side in FIG. 2 is connected to the downstream side of the intake pipe from the throttle valve 306 (see FIG. 1) in the intake pipe 302. Specifically, in FIG. 2, the downstream connection pipe DC on the left side is connected to the intake collector 310. However, in FIG. 2, the downstream connecting pipe DC on the left side may be connected to the intake pipe 302 between the throttle valve 306 and the intake collector 310. Further, in FIG. 2, the downstream side connecting pipe DC on the right side is connected to the upstream side of the intake pipe from the throttle valve 306 in the intake pipe 302. Specifically, in FIG. 2, the downstream connecting pipe DC on the right side is connected to the intake pipe 302 between the air cleaner 304 (see FIG. 1) and the throttle valve 306.

As a result, the oil separator 402 on the right side in FIG. 2 pumps air (fresh air) into the crank chamber when, for example, the pressure in the intake pipe 302 on the upstream side of the throttle valve 306 is higher than the pressure in the crank chamber 218. Lead to 218. Further, in FIG. 2, the oil separator 402 on the left side blows blow-by gas from the crank chamber 218 to the intake collector when, for example, the pressure in the intake collector 310 on the downstream side of the throttle valve 306 is lower than the pressure in the crank chamber 218. Lead to 310.

The main body 404 is arranged between the upstream side connecting pipe UC and the downstream side connecting pipe DC. The body 404 is at least partially disposed between a plurality (two in this embodiment) of intake branches 312. A blow-by gas flow path 406 through which blow-by gas can flow is formed inside the main body 404. A plurality of collision plates 408 are arranged in the blow-by gas flow path 406.

As shown in FIG. 3, the main body 404 includes a narrowing portion 410 and an expanding portion 412. The constriction portion 410 is arranged between the plurality of intake branches 312. The expansion portion 412 is continuously formed with the narrowing portion 410, and is arranged vertically above (upper side in FIG. 3) of the plurality of intake branches 312. Further, as shown in FIG. 2, the expansion portion 412 is arranged vertically above (upper side in FIG. 2) of the curved portion 312a formed in the plurality of intake branches 312.

As shown in FIG. 3, in the cross section perpendicular to the flow direction in which the blow-by gas flows, the blow-by gas flow path 406 has a flow path cross section of the expansion portion 412 rather than a flow path cross section of the narrowing portion 410. Is big. As a result, the expansion portion 412 has a larger volume of the blow-by gas flow path 406 than the narrowing portion 410.

As shown in FIG. 2, the plurality of collision plates 408 are arranged side by side along the flow direction of the blow-by gas. The plurality of collision plates 408 are arranged alternately along the flow direction of the blow-by gas. The collision plate 408 has a plane approximately perpendicular to the flow direction of blow-by gas. However, the collision plate 408 may be configured to have a plane approximately perpendicular to the vertical direction, or may be configured to have a plane approximately perpendicular to the horizontal direction.

In order to allow blow-by gas to flow in the blow-by gas flow path 406, a space S (see FIG. 3) is provided between the collision plate 408 and a part of the inner peripheral surface of the main body 404 (blow-by gas flow path 406). Be done. The two spaces S formed between the two adjacent collision plates 408 and the inner peripheral surface of the main body 404 are formed at different positions that do not overlap each other when viewed from the flow direction of the blow-by gas.

The blow-by gas collides with the collision plate 408 in the process of flowing through the blow-by gas flow path 406. When the blow-by gas collides with the collision plate 408, the blow-by gas changes its moving direction so as to bypass the collision plate 408. A part of the blow-by gas whose movement direction has been changed passes through the space S and moves again along the flow direction of the blow-by gas.

When the blow-by gas collides with the collision plate 408, the oil (a part of the oil mist) contained in the blow-by gas is separated by the impact of the collision. Further, when the moving direction of the blow-by gas is changed so as to bypass the collision plate 408, the oil (a part of the oil mist) contained in the blow-by gas is separated by the centrifugal force.

In this way, the main body 404 separates the oil contained in the blow-by gas. The blow-by gas from which the oil has been separated through the main body 404 (collision plate 408) is returned to the intake pipe 302 (intake flow path) via the downstream connecting pipe DC. The blow-by gas returned to the intake pipe 302 is guided to the intake port IP of the engine 200 and is burned in the combustion chamber of the engine 200.

As shown in FIG. 3, when the end of the collision plate 408 on the lower side in the vertical direction (lower side in FIG. 3) is connected to the inner peripheral surface of the main body 404, the lower end in the vertical direction An opening 408a is formed in the space. In the present embodiment, the opening 408a has a substantially semicircular shape. However, the opening 408a may be formed in a shape different from the substantially semicircular shape, for example, may be formed in a circular shape, or may be formed in a rectangular shape. The opening 408a is formed in a size that allows oil (a part of oil mist) separated from blow-by gas to flow.

The oil separated from the blow-by gas moves vertically downward along the direction opposite to the flow direction of the blow-by gas (white arrow in FIG. 2). Specifically, the oil separated from the blow-by gas in the main body 404 moves in the main body 404 and the upstream connecting pipe UC in the direction opposite to the white arrow in FIG.

As a result, the oil separated from the blow-by gas is returned from the oil separation device 402 to the crankcases 210a and 210b. The oil returned to the crankcases 210a and 210b falls vertically downward in the crankcase 218 and is returned to the oil pan 234.

As described above, according to the present embodiment, the oil separation device 402 is arranged outside the engine 200 and is arranged at a position vertically above the engine 200. The oil mist contained in the blow-by gas exerts a force in the direction of separating from the blow-by gas due to gravity. Therefore, the amount of oil mist contained in the blow-by gas is reduced as it moves vertically upward. Therefore, the oil mist is less likely to flow into the oil separation device 402 when it is located vertically above the outside of the engine 200 than when it is arranged inside the engine 200.

In the oil separation device 402, the outflow amount of the oil mist decreases as the inflow amount of the oil mist decreases. As a result, the oil separation device 402 can suppress an increase in the consumption of engine oil, deterioration of fuel consumption, seizure of the engine 200, and the like.

Further, the oil separation device 402 includes a main body 404 (narrowing portion 410) arranged between the plurality of intake branches 312. As a result, the oil separation device 402 can effectively utilize the dead space between the plurality of intake branches 312, and it is not necessary to secure a new space for arranging the oil separation device 402.

Further, the oil separating device 402 includes a narrowing portion 410 and an expanding portion 412. The expansion portion 412 has a larger space than the narrowing portion 410. Therefore, when the blow-by gas moves from the narrowing portion 410 to the expanding portion 412, the flow velocity decreases. As a result, the blow-by gas has a longer time to collide with the collision plate 408 in the expansion portion 412 than in the narrowing portion 410. As a result, in the oil separation device 402, the amount of separation of the oil mist contained in the blow-by gas is larger in the expansion portion 412 than in the narrowing portion 410.

Here, the oil separation device 402 arranges the expansion portion 412 at a position vertically above the curved portion 312a of the intake branch 312. The space vertically above the curved portion 312a is formed as a dead space. Further, a space between the upper surface of the intake branch 312 (upper surface in FIG. 2) and the upper surface of the intake collector 310 (upper surface in FIG. 2) is also formed as a dead space. Therefore, if the upper surface of the expansion portion 412 does not exceed the upper surface of the intake collector 310 in the vertically upward direction, the expansion portion 412 effectively eliminates the dead space without securing a new space for arranging the oil separation device 402. It can be utilized. Further, since the expansion portion 412 is located vertically above the curved portion 312a, the amount of oil mist separated from the blow-by gas due to gravity can be increased.

Further, the oil separation device 402 is provided with a PCV valve PV in the downstream connection pipe DC. As described above, the oil (oil mist) collected by the main body 404 is returned to the oil pan 234 through the upstream connecting pipe UC. Therefore, when the PCV valve PV is provided in the upstream connecting pipe UC, the oil collected by the main body 404 is blocked by the PCV valve PV when passing through the upstream connecting pipe UC, and it is difficult to return to the oil pan 234. Become. Therefore, in the present embodiment, the PCV valve PV is not provided in the upstream connecting pipe UC, but is provided in the downstream connecting pipe DC. As a result, the oil separating device 402 can easily return the oil collected by the main body 404 to the oil pan 234.

In this embodiment, an example in which the PCV valve PV is provided in the downstream connection pipe DC has been described. However, the PCV valve PV has a blow-by gas flow path with respect to the collision plate 408 arranged on the most downstream side in the distribution direction (in the direction of the white arrow in FIG. 2) through which the blow-by gas flows, among the plurality of collision plates 408. It suffices if it is arranged on the downstream side of 406. Therefore, the PCV valve PV may be provided in the main body 404 (blow-by gas flow path 406), for example.

Further, the oil separation device 402 includes a main body 404 arranged between a plurality of intake branches 312, and the main body 404 is integrally molded with the intake manifold 308 (intake branch 312). As a result, the oil separation device 402 can improve the rigidity of the intake manifold 308 (intake branch 312). As a result, the oil separation device 402 can reduce the noise generated from the intake manifold 308 (intake branch 312) (for example, the intake noise and the radiated noise caused by the vibration transmitted from the engine 200).

Further, in the present embodiment, the main body 404 is integrally formed with the upstream side connecting pipe UC and the downstream side connecting pipe DC. Therefore, the cost of the oil separation device 402 can be reduced as compared with the case where the upstream side connecting pipe UC, the main body 404, and the downstream side connecting pipe DC are separately formed. Further, the oil separation device 402 can connect the upstream side connecting pipe UC to the engine 200 (crankcases 210a and 210b) when the intake manifold 308 is attached to the engine 200. Therefore, when the intake manifold 308 is attached to the engine 200, the operator can attach the oil separation device 402 to the engine 200, which simplifies the installation work of the oil separation device 402.

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 come up with various modifications or modifications within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention. Will be done.

In the above embodiment, an example in which the main body 404 includes both the narrowing portion 410 and the expanding portion 412 has been described. However, the configuration of the expansion unit 412 is not essential. Therefore, the main body 404 may include only the narrowing portion 410 without the expanding portion 412.

In the above embodiment, an example in which the main body 404 is integrally formed with the intake manifold 308 has been described. However, the present invention is not limited to this, and the main body 404 may be formed separately from the intake manifold 308. In that case, the main body 404 is preferably formed so as to have a contact surface in contact with the outer surface of the intake manifold 308 (intake branch 312). By contacting the main body 404 with the intake manifold 308 (intake branch 312), the rigidity of the intake manifold 308 (intake branch 312) can be improved. As the contact area of the main body 404 with the intake manifold 308 (intake branch 312) becomes larger, the rigidity of the intake manifold 308 (intake branch 312) can be improved.

The present invention can be used in an oil separator.

200 Engine 308 Intake manifold 310 Intake collector 312 Intake branch 312a Curved part 402 Oil separator 404 Main body 406 Blow-by gas flow path 408 Collision plate 410 Narrowing part 412 Expansion part IP Intake port PV PCV valve (valve)

Claims (4)

A main body arranged between a plurality of intake branches connecting the intake port of the engine and the intake collector of the intake manifold arranged vertically above the engine.
A blow-by gas flow path formed inside the main body and capable of flowing blow-by gas,
The collision plate arranged in the blow-by gas flow path and
An oil separator equipped with. The intake branch has a curved portion and has a curved portion.
The main body has a constricted portion arranged between the plurality of intake branches and an expansion portion continuous with the constricted portion and arranged vertically above the curved portion.
The first aspect of claim 1 is that the blow-by gas flow path has a cross section perpendicular to the flow direction in which the blow-by gas flows, and the flow path cross section of the expansion portion is larger than the flow path cross section of the narrowed portion. Oil separator. A plurality of the collision plates are arranged in the blow-by gas flow path.
Claim 1 or 2 in which the blow-by gas flow path has a valve arranged on the downstream side of the collision plate arranged on the most downstream side in the distribution direction in which the blow-by gas flows. The oil separator described in. The oil separation device according to any one of claims 1 to 3, wherein the main body is integrally formed with the intake manifold.

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