JP2022025501A - Blow-by gas treatment device - Google Patents

Abstract

To provide a blow-by gas treatment device which can suppress the generation of white smoke due to a moisture content in a blow-by gas.SOLUTION: A blow-by gas treatment device 100 of an internal combustion engine 1 includes a blow-by gas passage 10 having an outlet part 10out opened to the atmosphere, and an adjustment part 20 which is provided in the outlet part 10out and changes a flow passage cross-sectional area S1 of the outlet part 10out according to a flow rate of a blow-by gas B.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to blow-by gas processing equipment.

In an internal combustion engine, a blow-by gas processing device that releases blow-by gas leaked into a crankcase from a gap between a piston and a cylinder to the atmosphere from an outlet of a blow-by gas passage is known.

Japanese Unexamined Patent Publication No. 2001-123817 Japanese Unexamined Patent Publication No. 2007-64134

However, in the above blow-by gas processing apparatus, white smoke may be generated around the outlet portion of the blow-by gas passage due to the moisture in the blow-by gas. In this case, the cause of the white smoke may be mistaken as an abnormality of the internal combustion engine, which may lead to unnecessary maintenance.

Therefore, the present disclosure has been devised in view of such circumstances, and an object thereof is to provide a blow-by gas treatment apparatus capable of suppressing the generation of white smoke due to moisture in blow-by gas.

According to one aspect of the present disclosure, it is a blow-by gas processing apparatus for an internal combustion engine, the blow-by gas passage having an outlet portion open to the atmosphere, and the outlet portion provided at the outlet portion according to the flow rate of the blow-by gas. A blow-by gas processing apparatus is provided, which comprises an adjusting portion for changing the cross-sectional area of the flow path of the above.

Preferably, the adjusting portion increases the flow path cross-sectional area of the outlet portion as the flow rate of the blow-by gas increases.

Further, the adjusting portion is provided inside the outlet portion and includes a leaf spring that changes the opening degree of the outlet portion according to the flow rate of the blow-by gas.

Further, the adjusting unit includes a shutter mechanism for opening and closing the outlet unit and a control unit for controlling the opening and closing of the shutter mechanism.

Further, the adjusting portion is formed of an elastic material and includes a nozzle that expands and contracts in the radial direction according to the flow rate of blow-by gas.

According to the blow-by gas treatment apparatus of the present disclosure, it is possible to suppress the generation of white smoke due to the moisture in the blow-by gas.

It is an overall block diagram of the internal combustion engine including the blow-by gas processing apparatus of 1st Embodiment. It is an enlarged perspective view of the blow-by gas processing apparatus shown in the part II of FIG. It is an enlarged sectional view of the left side view shown by the line III-III of FIG. It is an enlarged sectional view of the left side view which shows the comparative example of 1st Embodiment. It is an overall block diagram of the internal combustion engine including the blow-by gas processing apparatus of 2nd Embodiment. It is an enlarged perspective view of the blow-by gas processing apparatus shown in the VI part of FIG. It is an enlarged cross-sectional view of the left side view shown by the VII-VII line shown in FIG. This is a map that defines the relationship between the blow-by gas flow rate and the opening of the outlet. It is a flowchart which shows the control content of a control part. It is an enlarged perspective view of the blow-by gas processing apparatus of 3rd Embodiment. It is an enlarged cross-sectional view of the left side view shown by the XI-XI line of FIG. It is a flowchart which shows the control content of the 1st modification. It is an enlarged sectional view of the blow-by gas processing apparatus of the 2nd modification. It is an enlarged sectional view of the rear view shown by the XIV-XIV line of FIG.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the following embodiments. Further, each direction of up, down, front, back, left, and right shown in the figure coincides with each direction of the vehicle (not shown) equipped with the internal combustion engine 1, although it is only defined for convenience of explanation.

(1) First Embodiment First, the overall configuration of the internal combustion engine 1 of the first embodiment will be described with reference to FIG. 1. In the figure, the white arrow A indicates the flow of intake air, and the black arrow G indicates the flow of exhaust gas.

As shown in FIG. 1, the internal combustion engine 1 is a multi-cylinder compression ignition type internal combustion engine mounted on a vehicle, for example, a diesel engine. The vehicle is a large vehicle such as a truck. However, the type, type, application, etc. of the vehicle and the internal combustion engine 1 are not particularly limited. For example, the vehicle may be a small vehicle such as a passenger car, and the internal combustion engine 1 is a spark ignition type internal combustion engine such as a gasoline engine. It may be. The internal combustion engine 1 may be mounted on a moving body other than a vehicle, for example, a ship, a construction machine, or an industrial machine. Further, the internal combustion engine 1 does not have to be mounted on a moving body, and may be a stationary type.

The internal combustion engine 1 includes an engine main body 2, an intake passage 3, an exhaust passage 4, and a turbocharger 5.

Although not shown, the engine body 2 includes structural parts such as a cylinder head, a cylinder block, and a crankcase, and moving parts such as a piston, a crankshaft, and a valve mechanism housed therein. Reference numeral 2a is a head cover connected to the upper part of the cylinder head.

The intake passage 3 is mainly defined by an intake manifold 3a connected to the engine body 2 (particularly, a cylinder head) and an intake pipe 3b connected to the upstream end of the intake manifold 3a.

The intake manifold 3a distributes and supplies the intake air sent from the intake pipe 3b to the intake ports of each cylinder.

The intake pipe 3b is provided with an air cleaner 3c, a turbocharger 5 compressor 5C, and an intercooler 3d in this order from the upstream side.

The exhaust passage 4 is mainly defined by an exhaust manifold 4a connected to the engine body 2 (particularly, a cylinder head) and an exhaust pipe 4b arranged on the downstream side of the exhaust manifold 4a.

The exhaust manifold 4a collects the exhaust gas sent from the exhaust port of each cylinder. A turbine 5T of the turbocharger 5 is provided between the exhaust manifold 4a and the exhaust pipe 4b.

Next, the configuration of the blow-by gas processing apparatus 100 of the first embodiment will be described with reference to FIGS. 1 to 3. In the figure, the shaded arrow B indicates the flow of blow-by gas.

As shown in FIG. 1, an in-engine passage 6 through which blow-by gas B flows is provided inside the engine body 2. As is well known, the blow-by gas B is a gas leaked into the crankcase from the gap between the cylinder and the piston.

The engine passage 6 passes from the inside of the crankcase through the inside of the cylinder block and the cylinder head and extends into the head cover 2a. At the rear end of the head cover 2a, an outlet 6out of the passage 6 in the engine is formed. The upstream end of the blow-by gas pipe 10, which will be described later, is connected to the outlet 6out of the passage 6 in the engine.

The blow-by gas processing apparatus 100 is provided with a blow-by gas pipe 10 as a blow-by gas passage whose outlet portion 10 out is open to the atmosphere, and a flow path cross-sectional area of the outlet portion 10 out according to the flow rate of the blow-by gas B. An adjusting unit 20 for changing is provided.

The blow-by gas pipe 10 is a resin pipe such as a rubber hose, and is arranged outside the engine body 2. An oil separator 7 for removing oil from the blow-by gas B is provided in the middle of the blow-by gas pipe 10.

In the oil separator 7, oil is separated from the blow-by gas B introduced therein. The oil separated from the blow-by gas B is returned into the crankcase through an oil return passage (not shown).

As shown in FIG. 2, the outlet portion 10out of the blow-by gas pipe 10 is formed by a downstream end portion 10a of the blow-by gas pipe 10 and an outlet pipe 11 connected to the downstream end portion 10a.

The downstream end portion 10a and the outlet pipe 11 extend from the front to the rear along the flow direction of the blow-by gas B. In the figure, the alternate long and short dash line C indicates the common central axis of the downstream end portion 10a and the outlet pipe 11.

The outlet pipe 11 is made of a resin material or a metal material. Further, the outlet pipe 11 has an outlet pipe main body 12 formed in a rectangular tubular cross section, and an outlet pipe fixing portion 13 formed in a circular tubular shape and connected to the front end of the outlet pipe main body 12.

The outlet pipe main body 12 has inner wall surfaces 12a and 12b on both the upper and lower sides extending in the left-right direction, and inner wall surfaces 12c and 12d on both the left and right sides extending in the up-down direction.

The outlet pipe fixing portion 13 is formed by expanding the diameter from the front end of the outlet pipe main body 12, and is fitted and fixed to the inside of the downstream end portion 10a of the blow-by gas pipe 10.

As shown in FIG. 3, the adjusting unit 20 of the first embodiment is provided inside the outlet pipe 11 (outlet pipe main body 12), and the flow path cross-sectional area of the outlet pipe 11, that is, is opened according to the flow rate of the blow-by gas B. A leaf spring 21 that changes the degree S1 is provided.

The leaf spring 21 is configured to increase the opening degree S1 of the outlet pipe 11 as the flow rate of the blow-by gas B increases.

The leaf spring 21 of the first embodiment is a rectangular flat plate member, and is made of a metal material or a resin material. The leaf spring 21 is arranged so as to extend in the front-rear direction along the inner wall surface 12a on the upper side of the outlet pipe main body 12.

The base end portion (front end portion) 21a of the leaf spring 21 is fixed to the inner wall surface 12a on the upper side of the outlet pipe main body 12 by bolting. Further, the leaf spring 21 is gradually inclined downward from the front end portion 21a toward the rear.

On the other hand, the tip end portion (rear end portion) 21b of the leaf spring 21 is always arranged so as to be upwardly separated from the inner wall surface 12b on the lower side of the outlet pipe main body 12, and a flow path is formed between them. .. In the first embodiment, the opening degree S1 of the outlet portion 10out to the outlet pipe 11 means the flow path cross-sectional area of this flow path.

On the other hand, as shown in FIG. 2, the left end portion 21c of the leaf spring 21 is slidably arranged with respect to the inner wall surface 12c on the left side of the outlet pipe main body 12, and the right end portion 21d of the leaf spring 21 is the outlet pipe main body. It is slidably arranged with respect to the inner wall surface 12d on the right side of the twelve.

As shown by the arrow X1 in FIG. 3, the leaf spring 21 is pushed by the blow-by gas B and elastically deformed so that the rear end portion 21b moves upward with the front end portion 21a fixed by bolting as a base point. Rotates to. The outlet pipe main body 12 is formed to be longer in the vertical direction than in the horizontal direction in a cross-sectional view perpendicular to the axial direction so that a sufficient rotation distance of the leaf spring 21 can be secured.

In FIG. 3, reference numeral P1 indicates the position of the leaf spring 21 (hereinafter, the first leaf spring position) when the flow rate of the blow-by gas B is equal to or less than a predetermined lower limit threshold value (for example, when the internal combustion engine 1 is in a low load operation state). Is shown. At this time, the leaf spring 21 is in a natural state (initial state) in which it is not elastically deformed, and the rear end portion 21b of the leaf spring 21 is located below the central axis C of the outlet pipe 11 and is located in the outlet pipe 11. The opening degree S1 is the minimum opening degree S1min (S1 = S1min).

The leaf spring 21 is pushed by the blow-by gas B and rotates more greatly as the flow rate and the flow velocity of the blow-by gas B introduced into the outlet pipe 11 become larger, and the opening degree S1 of the outlet pipe 11 is increased.

In FIG. 3, reference numeral P2 indicates the position of the leaf spring 21 (hereinafter, the second leaf spring position) when the flow rate of the blow-by gas B is equal to or higher than a predetermined upper limit threshold value (for example, when the internal combustion engine 1 is in a high load operation state). Is shown. At this time, the rear end portion 21b of the leaf spring 21 is located above the central axis C of the outlet pipe 11, and the opening degree S1 of the outlet pipe 11 becomes the maximum opening degree S1max (S1 = S1max).

Further, as will be described in detail later, the leaf spring 21 is arranged so as not to protrude into the atmosphere from the downstream end 11a of the outlet pipe 11 even when the maximum opening is S1max, regardless of the opening degree S1 of the outlet pipe 11. To.

Next, the operation and effect of the blow-by gas treatment apparatus 100 according to the first embodiment will be described in detail.

As shown in FIG. 1, in the first embodiment, while the internal combustion engine 1 is in operation, the blow-by gas B in the crankcase flows through the engine passage 6 and the blow-by gas pipe 10 in order, and is open to the atmosphere from the outlet pipe 11. Will be done.

In a general blow-by gas processing device, an outlet pipe and a leaf spring are not provided at the outlet portion, and the flow path cross-sectional area of the outlet portion cannot be changed according to the flow rate of the blow-by gas.

However, in such a blow-by gas treatment device, white smoke may be generated around the outlet portion due to the moisture in the blow-by gas released to the atmosphere from the outlet portion. That is, in an environment where the atmospheric temperature is low, water vapor, which is an invisible gas contained in blow-by gas, is cooled by the outside air immediately after being discharged from the blow-by gas pipe. When the temperature of the steam becomes lower than the dew point temperature, the steam condenses and further aggregates to appear as visible water droplets, that is, steam. This steam is the true identity of white smoke.

In particular, when the flow rate of the blow-by gas is low, the flow velocity of the blow-by gas discharged from the outlet portion is smaller than when the flow rate of the blow-by gas is high. Therefore, there is a possibility that the water vapor contained in the blow-by gas cannot be blown away and diffused into the atmosphere, and as a result, white smoke is likely to be generated around the outlet portion.

In this case, the cause of the white smoke may be mistaken as an abnormality of the internal combustion engine, which may lead to unnecessary maintenance.

On the other hand, as shown in FIG. 3, in the first embodiment, the leaf spring 21 rotates from the first leaf spring position P1 when the flow rate of the blow-by gas B is small, specifically, when the flow rate is equal to or less than the lower limit threshold value. Instead, the opening degree S1 of the outlet pipe 11 becomes the minimum opening degree S1min. As a result, the flow velocity of the blow-by gas B discharged from the outlet pipe 11 can be increased, and the blow-by gas B can be ejected into the atmosphere. Therefore, even when the flow rate of the blow-by gas B is equal to or less than the lower limit threshold value, the water vapor contained in the blow-by gas B can be blown away and diffused into the atmosphere.

As a result, even when the temperature of steam becomes lower than the dew point temperature in an environment where the atmospheric temperature is low, the aggregation of steam can be suppressed and the generation of steam (white smoke) can be suppressed.

Therefore, the blow-by gas treatment device 100 of the first embodiment can suppress the generation of white smoke due to the moisture in the blow-by gas. As a result, it is possible to prevent unnecessary maintenance from being performed by misidentifying that the cause of the white smoke is an abnormality of the internal combustion engine 1. Further, if white smoke is generated, the cause of the white smoke can be identified by focusing on the causes other than the moisture in the blow-by gas, so that the maintenance can be made more efficient.

Further, in the leaf spring 21 of the first embodiment, the larger the flow rate and the flow velocity of the blow-by gas B introduced into the outlet pipe 11, the larger the opening degree S1 of the outlet pipe 11 and the more the flow of the blow-by gas B is not obstructed. It can be ejected into the atmosphere.

When the flow rate of the blow-by gas B is equal to or higher than the upper limit threshold value, the leaf spring 21 is rotated and located at the second leaf spring position P2, and the opening degree S1 of the outlet pipe 11 becomes the maximum opening degree S1max (S1 = S1max). As a result, the blow-by gas B can be smoothly discharged into the atmosphere. Further, when the flow rate of the blow-by gas B introduced into the outlet pipe 11 is large, the flow velocity is also large, so that even if the opening degree S1 of the outlet pipe 11 is large, the water vapor contained in the blow-by gas B is blown away to the atmosphere. It diffuses into the air and can suppress the generation of white smoke.

Therefore, in the first embodiment, the water vapor contained in the blow-by gas B can be blown away and diffused into the atmosphere regardless of the flow rate of the blow-by gas B.

Here, FIG. 4 is an enlarged cross-sectional view of a left side view showing a comparative example of the first embodiment. As shown in FIG. 4, in this comparative example, since the rear end portion 21b of the leaf spring 21 protrudes into the atmosphere from the downstream end 11a of the outlet pipe 11, there is a risk of contact with parts around the outlet pipe 11. be. Further, in this case, the blow-by gas B tends to flow into the atmosphere along the rear end portion 21b of the leaf spring 21. Therefore, for example, when the position of the leaf spring 21 changes from the first leaf spring position P1 to the second leaf spring position P2, the flow direction of the blow-by gas B may change, and the blow-by gas B may hit the peripheral parts. be.

On the other hand, as shown in FIG. 3, the rear end portion 21b of the leaf spring 21 of the first embodiment protrudes into the atmosphere from the downstream end 11a of the outlet pipe 11 regardless of the opening degree S1 of the outlet pipe 11. Therefore, it is possible to avoid contact with the parts around the outlet pipe 11. Further, since the blow-by gas B tends to flow into the atmosphere along the inner wall surface 12b on the lower side of the outlet pipe main body 12 located behind the rear end portion 21b of the leaf spring 21, the position of the leaf spring 21 Even if the flow direction of the blow-by gas B changes, the flow direction of the blow-by gas B can be kept constant and difficult to change. As a result, it is possible to suppress the blow-by gas B from hitting the peripheral parts.

(Second Embodiment)
The blow-by gas treatment apparatus 200 of the second embodiment will be described with reference to FIGS. 5 to 9. In the following description, the same reference numerals are used for the same components as those in the first embodiment, and detailed description thereof will be omitted.

As shown in FIGS. 5 to 7, in the second embodiment, the configurations of the adjusting unit 20 and the outlet pipe 11 are different from those of the first embodiment.

As shown in FIG. 6, the adjusting unit 20 of the second embodiment is not the leaf spring 21 described in the first embodiment, but the shutter mechanism 30 for opening and closing the outlet pipe 11 and the control for controlling the opening and closing of the shutter mechanism 30. An electronic control unit (ECU) 40 as a unit is provided. Further, the adjusting unit 20 of the second embodiment includes a flow rate sensor 41 for detecting the flow rate of the blow-by gas B.

The outlet pipe main body 12 of the second embodiment is formed in a square tubular shape having a rectangular cross section. However, the front upper surface portion 12e of the outlet pipe main body 12 is gradually curved downward from the front to the rear. The outlet pipe main body 12 has a blow-by gas outlet 14 formed along the front upper surface portion 12e.

Further, the outlet pipe main body 12 of the second embodiment has a shaft case 15 for accommodating the shaft 33 of the shutter mechanism 30. The shaft case 15 is installed on the rear upper surface portion 12f of the outlet pipe main body 12 and communicates with the inside of the outlet pipe main body 12.

The shutter mechanism 30 is arranged along the guide rails 31a and 31b provided on the inner walls on both the left and right sides of the outlet pipe main body 12 along the blow-by gas outlet 14 and the guide rails 31a and 31b to open and close the blow-by gas outlet 14. The shutter body 32 and the shutter body 32 are provided. Further, the shutter mechanism 30 includes a shaft 33 capable of winding out the shutter main body 32 and a motor 34 for rotationally driving the shaft 33.

The guide rails 31a and 31b on both the left and right sides have a pair of upper and lower rail members R1 and R2, respectively. The rail members R1 and R2 are slidably supported by sandwiching the left and right end portions of the shutter main body 32 in the thickness direction.

The shutter body 32 is a so-called slat in which rectangular flat plate members are connected in a bellows shape, and is made of a resin material or a metal material. The upper end portion 32a of the shutter body 32 is attached to the outer peripheral portion of the shaft 33.

The lower end portion 32b of the shutter main body 32 is always arranged upwardly separated from the lower end position of the blow-by gas outlet 14, and a flow path is formed between them. In the second embodiment, the opening degree S2 of the outlet pipe 11 means the flow path cross-sectional area of this flow path.

The shaft 33 is arranged so as to extend in the left-right direction and is rotatably supported by the shaft case 15.

The motor 34 is attached to the right wall portion of the shaft case 15. Further, the motor 34 has a rotation shaft (not shown) connected to the right end portion of the shaft 33.

Further, the motor 34 is a motor (for example, a DC motor or a stepping motor) that adjusts the rotation angle (phase) of the shaft 33, and is electrically connected to the ECU 40.

In FIG. 7, reference numeral P3 indicates a lower end position (hereinafter, first shutter position) of the shutter main body 32 when the opening degree S2 is the minimum opening degree S2min (S2 = S2min). At this time, the lower end portion 32b of the shutter main body 32 is located below the central axis C of the outlet pipe 11.

The shutter body 32 moves in the direction (upward) of the arrow X2 from the first shutter position P3 by adjusting the rotation angle of the shaft 33 by the motor 34 and winding it around the shaft 33. As a result, the opening degree S2 of the outlet pipe 11 increases.

Further, the shutter main body 32 moves in the opposite direction (downward) of the arrow X2 by adjusting the rotation angle of the shaft 33 by the motor 34 and paying out from the shaft 33. As a result, the opening degree S2 of the outlet pipe 11 is reduced.

In FIG. 7, reference numeral P4 indicates a lower end position (hereinafter, second shutter position) of the shutter main body 32 when the opening degree S2 is the maximum opening degree S2max (S2 = S2max). At this time, the lower end portion 32b of the shutter main body 32 is positioned above the central axis C of the outlet pipe 11.

As shown in FIG. 5, the ECU 40 includes an electronic control device or a controller mounted on a vehicle, and includes a CPU, a ROM, a RAM, a storage device, an input / output port, and the like.

The flow rate sensor 41 is provided in the blow-by gas pipe 10 on the downstream side of the oil separator 7, and is electrically connected to the ECU 40. However, the flow rate sensor 41 may be provided at an arbitrary position, and may be provided, for example, in the outlet pipe 11.

Further, the ECU 40 is configured to control the opening degree S2 of the outlet pipe 11 according to the flow rate Q of the blow-by gas B detected by the flow rate sensor 41.

Specifically, the ECU 40 controls the motor 34 of the shutter mechanism 30 based on the flow rate Q of the blow-by gas B detected by the flow rate sensor 41 with reference to the map M shown in FIG. 8, so that the outlet pipe 11 The opening degree S2 of is controlled. In FIG. 8, the vertical axis indicates the opening degree S2 of the outlet pipe 11, and the horizontal axis indicates the flow rate Q of the blow-by gas B.

As shown in FIG. 8, in the map M, when the flow rate Q of the blow-by gas B is equal to or less than the lower limit threshold value QL, the opening degree S2 is set to the minimum opening degree S2min, and the flow rate Q of the blow-by gas B is equal to or higher than the upper limit threshold value QH. , The opening degree S2 is set to the maximum opening degree S2max. Further, in the map M, when the flow rate Q of the blow-by gas B is larger than the lower limit threshold value QL and is less than the upper limit threshold value QH, the larger the flow rate Q of the blow-by gas B, the larger the opening degree S2 is set.

The control routine in the ECU 40 will be described with reference to FIG. The illustrated routine is repeatedly executed every predetermined calculation cycle (for example, 10 msec).

The ECU 40 acquires the flow rate Q of the blow-by gas B detected by the flow rate sensor 41 in step S101.

In step S102, the ECU 40 refers to the map M and acquires the opening degree S2 corresponding to the flow rate Q acquired in step S101.

In step S103, the ECU 40 controls the motor 34 of the shutter mechanism 30 so that the actual opening degree of the outlet pipe 11 becomes the opening degree S2 acquired in step S102, and controls the actual opening degree. Return.

The operation and effect of the blow-by gas treatment device 200 according to the second embodiment is the same as that of the first embodiment.

The ECU 40 of the second embodiment controls the opening degree S2 to the minimum opening degree S2min when the flow rate Q of the blow-by gas B detected by the flow rate sensor 41 is equal to or less than the lower limit threshold value QL. Therefore, the flow velocity of the blow-by gas B discharged from the outlet pipe 11 can be increased to eject the blow-by gas B into the atmosphere. As a result, even when the flow rate of the blow-by gas B is equal to or less than the lower limit threshold value QL, the water vapor contained in the blow-by gas B can be blown away and diffused into the atmosphere.

As a result, as in the first embodiment, even when the temperature of steam becomes lower than the dew point temperature in an environment where the atmospheric temperature is low, the aggregation of steam can be suppressed and the generation of steam (white smoke) can be suppressed. ..

Further, the ECU 40 controls the opening degree S2 more as the flow rate Q of the blow-by gas B detected by the flow rate sensor 41 increases, and when the flow rate Q of the blow-by gas B detected by the flow rate sensor 41 is equal to or higher than the upper limit threshold value QH. , The opening degree S2 is controlled to the maximum opening degree S2max. As a result, as in the first embodiment, the action and effect that the blow-by gas B can be smoothly discharged into the atmosphere can be obtained.

(Third Embodiment)
The blow-by gas processing apparatus 300 of the third embodiment will be described with reference to FIGS. 10 and 11. As shown in FIGS. 10 and 11, in the third embodiment, the configurations of the outlet portion 10out and the adjusting portion 20 are different from those of the first embodiment.

As shown in FIG. 10, the outlet portion 10out of the third embodiment does not include the outlet pipe 11 described in the first embodiment, but instead is connected to the downstream end portion 10a of the blow-by gas pipe 10. A nozzle 50 is provided.

Further, the adjusting unit 20 of the third embodiment does not include the leaf spring 21 described in the first embodiment, but instead includes a nozzle 50.

The nozzle 50 extends from the front to the rear along the flow direction of the blow-by gas B. The downstream end portion 10a and the nozzle 50 are each formed in a circular tube and are coaxially connected to each other.

Further, the nozzle 50 is formed of an elastic material and is configured to expand and contract in the radial direction according to the flow rate of the blow-by gas B.

Specifically, the nozzle 50 is made of a resin material such as rubber, and is integrally formed at the downstream end portion 10a of the blow-by gas pipe 10. Further, the nozzle 50 is formed in a tapered shape so that the outer diameter and the inner diameter are reduced from the front to the rear.

As shown by the arrow X3 in FIG. 11, the nozzle 50 is elastically deformed by being pushed by the blow-by gas B introduced therein, so that the tip portion (rear end portion) 50a is elastically deformed so as to expand in the radial direction. .. In the third embodiment, the flow path cross-sectional area S3 of the nozzle 50 means the flow path cross-sectional area of the rear end portion 50a of the nozzle 50.

Further, the nozzle 50 is formed so that the difference (thickness) t between the outer diameter and the inner diameter becomes smaller from the front to the rear. As a result, the rear end portion 50a of the nozzle 50 can be easily expanded and contracted, and the flow path cross-sectional area S3 can be easily changed.

Further, in the third embodiment, the wall thickness t of the nozzle 50 is set to a uniform size in the circumferential direction. This makes it possible to uniformly expand and contract the nozzle 50 in the circumferential direction. As a result, the blow-by gas B can be accurately flowed from the nozzle 50 to the downstream side in the axial direction and released to the atmosphere.

In FIG. 11, reference numeral P5 indicates the position of the nozzle 50 (hereinafter, the first nozzle position) when the flow rate of the blow-by gas B is equal to or less than the lower limit threshold value. At this time, the nozzle 50 is in a natural state (initial state) without elastic deformation, and the flow path cross-sectional area S3 of the nozzle 50 has a minimum area S3min (S3 = S3min).

The larger the flow rate and the flow velocity of the low-by gas B introduced into the nozzle 50, the larger the nozzle 50 is pushed by the blow-by gas B and expands outward in the radial direction, increasing the flow path cross-sectional area S3.

In FIG. 11, reference numeral P6 indicates the position of the nozzle 50 (hereinafter, the second nozzle position) when the flow path cross-sectional area S3 is equal to or larger than the upper limit threshold value. At this time, the flow path cross-sectional area S3 of the nozzle 50 has a maximum area S3max (S3 = S3max).

The operation and effect of the blow-by gas treatment device 300 according to the third embodiment is the same as that of the first embodiment.

As shown in FIG. 11, in the third embodiment, when the flow rate of the blow-by gas B is equal to or less than the lower limit threshold value, the nozzle 50 does not expand radially outward from the first nozzle position P5, and the flow path cross-sectional area S3 of the nozzle 50. Is the minimum area S3min (S3 = S3min). As a result, the flow velocity of the blow-by gas B discharged from the nozzle 50 can be increased, and the blow-by gas B can be ejected into the atmosphere. Therefore, even when the flow rate of the blow-by gas B is equal to or less than the lower limit threshold value, the water vapor contained in the blow-by gas B can be blown away and diffused into the atmosphere.

As a result, as in the first embodiment, even when the temperature of steam becomes lower than the dew point temperature in an environment where the atmospheric temperature is low, the aggregation of steam can be suppressed and the generation of steam (white smoke) can be suppressed. ..

Further, in the third embodiment, the larger the flow rate and the flow velocity of the blow-by gas B introduced into the nozzle 50, the larger the flow path cross-sectional area S3 of the nozzle 50, and when the flow rate of the blow-by gas B is equal to or higher than the upper limit threshold, the nozzle 50 extends outward in the radial direction and is located at the second nozzle position P6, and the flow path cross-sectional area S3 of the nozzle 50 becomes the maximum area S3max (S3 = S3max). As a result, as in the first embodiment, the action and effect that the blow-by gas B can be smoothly discharged into the atmosphere can be obtained.

Further, in the third embodiment, the nozzle 50 can be easily integrally formed with the blow-by gas pipe 10 only by forming the downstream end portion 10a of the blow-by gas pipe 10 by reducing the diameter in a tapered shape. However, the nozzle 50 may be formed separately from the blow-by gas pipe 10.

On the other hand, the above-described embodiment can be a modification or a combination thereof as follows.

(First modification)
The ECU 40 described in the second embodiment may control the opening degree S2 so as to switch between the minimum opening degree S2min and the maximum opening degree S2max.

Specifically, the ECU 40 of the first modification determines whether or not the flow rate Q of the blow-by gas B is equal to or higher than a predetermined threshold value, and if it is less than the threshold value, the opening degree S2 is set to the minimum opening degree S2min. When the threshold value is equal to or higher than the threshold value, the opening degree S2 is set to the maximum opening degree S2max. This makes it possible to simplify the control by the ECU 40.

The control routine of the first modification will be described with reference to FIG. The illustrated routine is repeatedly executed every predetermined calculation cycle (for example, 10 msec).

The ECU 40 of the first modification acquires the flow rate Q of the blow-by gas B detected by the flow rate sensor 41 in step S201, and the flow rate Q acquired in step S201 in step S202 is equal to or less than the threshold value QT ( It is determined whether or not Q ≦ QT).

If it is determined in step S202 that the flow rate Q is equal to or less than the threshold value QT (YES), the ECU 40 proceeds to step S203 and executes a control (S2 = S2min) to set the opening degree S2 to the minimum opening degree S2min. , Return.

On the other hand, if it is determined in step S202 that the flow rate Q is larger than the threshold value QT (NO), the ECU 40 proceeds to step S204 and executes control (S2 = S2max) to set the opening degree S2 to the maximum opening degree S2max. And return.

(Second modification)
As shown in FIG. 13, in the second modification, the nozzle 50 described in the third embodiment is radially outside with respect to the central axis C of the downstream end portion 10a of the blow-by gas pipe 10 (in the illustrated example, it is shown in the illustrated example. It is formed by being bent so as to incline downward). As a result, the blow-by gas B can flow diagonally downward from the nozzle 50 and open to the atmosphere. As a result, when the peripheral component is arranged directly behind the nozzle 50, it is possible to prevent the blow-by gas B from hitting the peripheral component.

Further, as shown in FIG. 14, in the nozzle 50 of the second modification, the wall thickness t1 of a part in the circumferential direction (the lower end portion in the illustrated example) is the wall thickness of the other part at the center position in the front-rear direction. It is formed smaller than t2 (t1 <t2). As a result, the nozzle 50 can be easily deformed downward. As a result, for example, even if the flow rate of the blow-by gas B changes, it can be easily adjusted so that the flow direction of the blow-by gas B is kept constant.

(Third modification example)
The outlet portion 10 out and the adjusting portion 20 may have any structure and shape. For example, the outlet pipe 11 described in the first embodiment may be integrally formed with the downstream end portion 10a of the blow-by gas pipe 10. Further, for example, the nozzle 50 described in the third embodiment may be formed in a square tubular shape.

Although the embodiments of the present disclosure have been described in detail above, the embodiments of the present disclosure are not limited to the above-described embodiments, and all modifications and applications included in the idea of the present disclosure defined by the scope of claims. For example, equivalents are included in this disclosure. Therefore, this disclosure should not be construed in a limited way and may be applied to any other technique that falls within the scope of the ideas of this disclosure.

1 Internal combustion engine 10 Blow-by gas pipe (blow-by gas passage)
10out Outlet part 20 Adjustment part 21 Leaf spring 100 Blow-by gas processing device B Blow-by gas S1 Opening (flow path cross-sectional area)

Claims (5)

It is a blow-by gas processing device for internal combustion engines.
A blow-by gas passage with the outlet open to the atmosphere,
A blow-by gas processing apparatus provided at the outlet portion and provided with an adjusting portion that changes the cross-sectional area of the flow path of the outlet portion according to the flow rate of the blow-by gas. The blow-by gas processing apparatus according to claim 1, wherein the adjusting portion increases the cross-sectional area of the flow path of the outlet portion as the flow rate of the blow-by gas increases. The blow-by gas processing apparatus according to claim 1 or 2, wherein the adjusting portion is provided inside the outlet portion and includes a leaf spring that changes the opening degree of the outlet portion according to the flow rate of the blow-by gas. The blow-by gas processing device according to claim 1 or 2, wherein the adjusting unit includes a shutter mechanism for opening and closing the outlet unit and a control unit for controlling the opening and closing of the shutter mechanism. The adjusting portion is formed of an elastic material and includes a nozzle that expands and contracts in the radial direction according to the flow rate of blow-by gas.
The blow-by gas processing apparatus according to claim 1.

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