JP2021195881A - Blow-by gas treatment device - Google Patents

Abstract

To provide a blow-by gas treatment device capable of suppressing generation of white smoke caused by moisture in blow-by gas.SOLUTION: A blow-by gas treatment device 100 for an internal combustion engine 1 includes a blow-by gas passage 10 and an atmosphere release pipe 20 for releasing blow-by gas B to the atmosphere. The atmosphere release pipe 20 includes: a gas inlet 21 for introducing the blow-by gas B; an air inlet 22 for introducing wind W sent from a cooling fan 3 of the internal combustion engine 1; and an outlet 23 for discharging the blow-by gas B to the atmosphere together with the wind W. The air inlet 22 is disposed to oppose to the wind W, and a flow passage cross sectional area S3 of the outlet 23 is smaller than a flow passage cross sectional area S2 of the air inlet 22.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a blow-by gas processing apparatus.

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 from a blow-by gas passage to the atmosphere is known.

Japanese Unexamined Patent Publication No. 11-350933

However, in the above blow-by gas treatment apparatus, white smoke may be generated around the downstream end 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, wherein the internal combustion engine includes an engine main body and a cooling fan for cooling the engine main body, and the blow-by gas processing apparatus is provided. The blow-by gas passage is provided with a blow-by gas passage through which the blow-by gas flows, and an air-opening pipe provided at the downstream end of the blow-by gas passage for opening the blow-by gas to the atmosphere. The air-opening pipe is provided from the blow-by gas passage. A gas inlet for introducing blow-by gas, an air inlet for introducing wind sent from the cooling fan, and an outlet for discharging blow-by gas introduced from the gas inlet into the atmosphere together with the wind introduced from the air inlet. The air inlet is arranged so as to face the wind sent from the cooling fan, and the flow path cross-sectional area of the outlet is smaller than the flow path cross-sectional area of the air inlet. Blow-by gas processing equipment is provided.

Preferably, the air release tube comprises a tubular body that extends axially, the air inlet is formed by one end of the body and directed towards the cooling fan, and the outlet is the body. It is formed by the other end of the air inlet and directed toward the opposite side of the air inlet, and the gas inlet is formed in the main body portion located between the air inlet and the outlet.

Further, the cross-sectional area of the flow path of the main body portion is gradually reduced from the air inlet to the outlet.

Further, the gas inlet is formed in a tubular shape protruding radially outward from the main body portion, and the atmospheric opening pipe is formed in a T shape.

Further, the air inlet is formed in a round hole shape, and the outlet is formed in a round hole shape, a vertically long hole shape, or a horizontally long hole shape.

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 an internal combustion engine including a blow-by gas processing apparatus. It is an enlarged sectional view of the blow-by gas processing apparatus shown in the part II of FIG. FIG. 3 is an enlarged cross-sectional view taken along line III-III shown in FIG. It is a rear view of the blow-by gas processing apparatus shown in FIG. It is an enlarged sectional view of the blow-by gas processing apparatus of 1st modification. It is an enlarged sectional view of the VI-VI line shown in FIG. It is a rear view of the blow-by gas processing apparatus shown in FIG. It is an enlarged sectional view of the blow-by gas processing apparatus of the 2nd modification. FIG. 8 is an enlarged cross-sectional view taken along the line IX-IX shown in FIG. It is a rear view of the blow-by gas processing apparatus shown in FIG. It is an enlarged sectional view of the blow-by gas processing apparatus of the 3rd modification.

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.

First, the overall configuration of the internal combustion engine 1 of the present embodiment will be described with reference to FIG. In the figure, the white arrow A indicates the flow of intake air, the black arrow G indicates the flow of exhaust air, and the shaded arrow W indicates the flow of wind or air sent from the cooling fan 3.

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 and a cooling fan 3 for cooling the engine main body 2. Further, the internal combustion engine 1 includes an intake passage 4, an exhaust passage 5, a turbocharger 6, and a radiator 7.

The engine body 2 includes a cylinder block 2a, a cylinder head 2b connected to the upper part of the cylinder block 2a, and a crankcase 2c integrally formed in the lower part of the cylinder block 2a. Further, the engine body 2 includes an oil pan 2d connected to the lower part of the crankcase 2c and a head cover 2e connected to the upper part of the cylinder head 2b.

Although not shown, the cylinder block 2a is provided with a plurality of cylinders, and the cylinders accommodate pistons. A valve operating mechanism such as a camshaft is attached to the cylinder head 2b, and the valve operating mechanism is covered from above by the head cover 2e. Further, a water jacket through which engine cooling water flows is formed in the cylinder block 2a and the cylinder head 2b.

The intake passage 4 includes an intake manifold (not shown) connected to the cylinder head 2b and an intake pipe 4a connected to the upstream end of the intake manifold.

The intake pipe 4a is provided with an air cleaner (not shown), a compressor 6C of the turbocharger 6, and an intercooler (not shown) in this order from the upstream side.

The exhaust passage 5 includes an exhaust manifold 5a connected to the cylinder head 2b and an exhaust pipe 5b arranged on the downstream side of the exhaust manifold 5a.

A turbine 6T of the turbocharger 6 is provided between the exhaust manifold 5a and the exhaust pipe 5b. The exhaust pipe 5b is provided with an exhaust throttle valve 5c and a post-treatment unit (not shown) for purifying the exhaust in order from the upstream side.

Although not shown, the aftertreatment unit includes an injector in the exhaust pipe that injects fuel into the exhaust pipe 5b, a diesel oxidation catalyst (DOC: Diesel Oxidation Catalyst), and a diesel particulate filter (DPF: Diesel Particulate Filter). .. The DOC oxidizes and purifies the hydrocarbon HC and carbon monoxide CO contained in the unburned components in the exhaust gas, and raises the temperature of the exhaust gas by the heat of oxidation. The DPF collects particulate matter (PM: Particulate Matter) contained in the exhaust gas. Further, the PM deposited on the DPF is burnt off by the exhaust gas heated by the DOC.

The exhaust throttle valve 5c is an electronically controlled flow rate adjusting valve (butterfly valve) that adjusts the flow rate of the exhaust gas flowing through the exhaust pipe 5b. The exhaust throttle valve 5c is electronically controlled by an electronic control unit (ECU) (not shown), and is closed during filter regeneration control or warm-up promotion control of the internal combustion engine 1.

The filter regeneration control is a control in which fuel is injected from an injector in the exhaust pipe and high-temperature exhaust gas is made to flow into the DPF from the DOC to burn and remove PM accumulated in the DPF. On the other hand, the warm-up promotion control is a control for promoting the warm-up of the internal combustion engine 1 during idle operation immediately after the start of the internal combustion engine 1.

The radiator 7 is arranged at a position in front of the crankcase 2c. Further, the radiator 7 is configured to cool the engine cooling water by passing air from the front to the rear.

The cooling fan 3 is arranged in front of and near the crankcase 2c and is driven by the rotation of the crankshaft. Further, the cooling fan 3 is arranged behind and in the vicinity of the radiator 7, and takes in air from the front and sends the wind W to the rear to generate an air flow passing through the radiator 7.

The wind W sent from the cooling fan 3 hits the engine body 2 to cool the engine body 2 and flows backward along the left and right side wall portions of the cylinder block a and the crankcase 2c.

Next, the configuration of the blow-by gas processing apparatus 100 of the present embodiment will be described with reference to FIGS. 1 to 4. In the figure, the dotted arrow B indicates the flow of blow-by gas.

As shown in FIG. 1, an in-engine passage 8 through which blow-by gas B flows is provided inside the engine body 2. As is well known, blow-by gas is gas that leaks into the crankcase 2c from the gap between the cylinder and the piston.

The in-engine passage 8 passes through the inside of the cylinder block 2a and the cylinder head 2b from the inside of the crankcase 2c and extends into the head cover 2e. A passage outlet 8a of the passage 8 in the engine is formed on the upper surface of the head cover 2e. The upstream end of the blow-by gas pipe 10, which will be described later, is connected to the passage outlet 8a of the passage 8 in the engine.

The blow-by gas processing device 100 includes a blow-by gas pipe 10 as a blow-by gas passage through which the blow-by gas B flows, and an air-opening pipe 20 provided at the downstream end portion 10a of the blow-by gas pipe 10 to open the blow-by gas to the atmosphere. , Equipped with.

The blow-by gas pipe 10 is made of a resin material such as rubber and is arranged outside the engine body 2. An oil separator 9 for removing oil from the blow-by gas B is provided in the middle of the blow-by gas pipe 10.

The oil separator 9 has a built-in filter element 9a and is installed on the upper surface of the head cover 2e. However, the type and position of the oil separator 9 may be arbitrary, and may be, for example, a centrifugal oil separator having no filter element.

In the oil separator 9, 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 2c through an oil return passage (not shown).

The downstream end portion 10a of the blow-by gas pipe 10 extends downward. The downstream end portion 10a of the blow-by gas pipe 10 and the atmosphere open pipe 20 are arranged close to the right side wall portion of the front end portion of the engine body 2 (crankcase 2c in this embodiment).

As shown in FIG. 2, the atmosphere opening pipe 20 is configured to introduce the wind W sent from the cooling fan 3 and discharge the blow-by gas B into the atmosphere together with the wind W.

The atmosphere opening pipe 20 has a gas inlet 21 for introducing blow-by gas B from the blow-by gas pipe 10, an air inlet 22 for introducing wind W sent from the cooling fan 3, and a blow-by gas B introduced from the gas inlet 21. It has an outlet 23 that discharges into the atmosphere together with the wind W introduced from the air inlet 22.

Further, the atmosphere opening pipe 20 includes a tubular main body portion 20a that extends linearly in the axial direction (in the present embodiment, the front-rear direction). In FIG. 2, the alternate long and short dash line C indicates the central axis of the main body portion 20a.

The main body portion 20a of the present embodiment is formed in a tapered shape so that the inner diameter and the outer diameter are gradually reduced from the front to the rear.

The air inlet 22 is arranged so as to face the wind W sent from the cooling fan 3. That is, the air inlet 22 is formed by one end (front end) of the main body 20a and is directed toward the cooling fan 3 so that the wind W sent from the cooling fan 3 can be directly introduced.

Further, the air inlet 22 is arranged behind and in the vicinity of the cooling fan 3 so that the wind W having a large flow velocity immediately after being sent from the cooling fan 3 can be introduced.

The outlet 23 is formed by the other end (rear end) of the main body 20a and is directed toward the opposite side (rear) of the air inlet 22 so that the wind W can be smoothly discharged without changing the flow direction.

The air inlet 22 and the outlet 23 are both formed in a round hole shape so as to simplify the shape of the main body portion 20a (see FIG. 4).

The gas inlet 21 is formed in the main body portion 20a located between the air inlet 22 and the outlet 23 (intermediate in this embodiment). The gas inlet 21 is formed in a round hole shape (see FIG. 3).

Further, the gas inlet 21 is formed in a tubular shape protruding radially outward (upward) from the main body portion 20a, and the atmosphere opening pipe 20 is formed in a T shape. The gas inlet 21 is fitted and fixed from below to the inside of the downstream end portion 10a of the blow-by gas pipe 10.

As shown in FIG. 3, the flow path cross-sectional area S3 of the outlet 23 is set to be smaller than the flow path cross-sectional area S2 of the air inlet 22 (S3 <S2). Further, the cross-sectional area of the flow path of the main body portion 20a is gradually reduced from the air inlet 22 toward the outlet 23. The action and effect of these flow path cross-sectional areas will be described later.

Further, the flow path cross-sectional area S1 of the gas inlet 21 is set to be smaller than the flow path cross-sectional area S3 of the outlet 23 and the flow path cross-sectional area S2 of the air inlet 22 (S1 <S3 <S2).

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

As shown in FIG. 1, while the internal combustion engine 1 is in operation, the blow-by gas B in the crankcase 2c flows through the engine passage 8 and the blow-by gas pipe 10 in order, and is introduced into the atmosphere opening pipe 20 from the gas inlet 21. .. The blow-by gas B introduced into the atmosphere opening pipe 20 is discharged from the outlet 23 together with the wind W introduced from the air inlet 22.

In a general blow-by gas treatment device, an atmospheric open pipe is not provided at the downstream end of the blow-by gas pipe. Therefore, the blow-by gas is directly discharged into the atmosphere from the downstream end of the blow-by gas pipe.

However, in such a blow-by gas treatment device, white smoke may be generated around the downstream end of the blow-by gas pipe due to the moisture in the blow-by gas. 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 exhaust throttle valve is closed during filter regeneration control or warm-up acceleration control during idle operation of the internal combustion engine, the fuel injection amount increases as the load on the internal combustion engine increases. As a result, the amount of water in the blow-by gas increases, so that white smoke tends to be easily generated.

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. 2, in the blow-by gas processing apparatus 100 of the present embodiment, the atmospheric open pipe 20 is provided at the downstream end portion 10a of the blow-by gas pipe 10.

As shown in FIG. 3, in the atmospheric opening pipe 20, the flow path cross-sectional area S3 of the outlet 23 is set to be smaller than the flow path cross-sectional area S2 of the air inlet 22 (S3 <S2). Therefore, the wind W introduced from the air inlet 22 into the main body 20a is ejected into the atmosphere from the outlet 23 by increasing the flow velocity. Then, the blow-by gas B is sucked into the main body 20a from the gas inlet 21 by the negative pressure generated by the wind W in the main body 20a, and is ejected into the atmosphere from the outlet 23 together with the accelerated wind W. As a result, 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 apparatus 100 of the present 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 present embodiment, the cross-sectional area of the flow path of the main body portion 20a is gradually reduced from the air inlet 22 toward the outlet 23. As a result, the flow velocity of the wind W in the main body portion 20a can be efficiently increased.

On the other hand, the above-described embodiment can be a modification or a combination thereof as follows. In the following description, the same reference numerals are used for the same components as those in the above embodiment, and detailed description thereof will be omitted.

(First modification)
As shown in FIGS. 5 to 7, in the first modification, the air inlet 22 has a round hole shape as in the above embodiment (see FIG. 4), but the outlet 23 is formed in a vertically long hole shape. To. Further, the main body portion 20a of the first modification is formed in a tapered shape so that the width in the lateral direction (left-right direction) is gradually reduced from the air inlet 22 toward the outlet 23. The cross-sectional shape of the main body portion 20a changes from a round hole shape to a vertically long long hole shape from the air inlet 22 toward the outlet 23.

In the first modification, the blow-by gas B can be ejected from the outlet 23 into a vertically long elongated hole shape. Therefore, for example, when a plurality of parts (not shown) of the internal combustion engine are arranged immediately after the outlet 23 and the gap between the parts is a vertically long narrow space, the blow-by gas B is ejected through the gap. can. As a result, it is possible to prevent the diffusion of water vapor in the blow-by gas from being hindered by contact with these parts. Further, it is possible to prevent these parts from being contaminated by contact with the blow-by gas B.

(Second modification)
As shown in FIGS. 8 to 10, in the second modification, the air inlet 22 has a round hole shape, but the outlet 23 has a horizontally long hole shape. Further, the main body portion 20a of the second modification is formed in a tapered shape so that the width in the vertical direction (vertical direction) is reduced from the air inlet 22 toward the outlet 23. The cross-sectional shape of the main body portion 20a changes from a round hole shape to a horizontally long long hole shape from the air inlet 22 toward the outlet 23.

In the second modification, the blow-by gas B can be ejected from the outlet 23 into a horizontally long hole shape. Therefore, when the gap between the parts described in the first modification is a horizontally long narrow space, the blow-by gas B is allowed to pass through the gap. Blow-by gas B can be ejected.

(Third modification example)
As shown in FIG. 11, the main body portion 20a of the third modification is formed of a curved pipe and is bent in a V shape at an intermediate position in the axial direction.

In the third modification, the front side portion 20b of the main body portion 20a extends in the front-rear direction, and the rear side portion 20c of the main body portion 20a faces the right side opposite to the engine main body 2 as it goes backward. Be tilted.

According to the third modification, the blow-by gas B is ejected diagonally to the right and rearward from the outlet 23. Therefore, for example, even when the component 11 of the internal combustion engine 1 is arranged at a position directly behind the main body 20a, it is possible to prevent the blow-by gas B from coming into contact with the component 11 and the engine body 2.

(Fourth modification)
Although not shown, the gas inlet 21, the air inlet 22, and the outlet 23 may have any shape. For example, in the fourth modification, both the air inlet 22 and the outlet 23 are formed in the shape of a vertically long elongated hole.

(Fifth modification)
The flow path cross-sectional area of the gas inlet 21 may have any size. For example, the flow path cross-sectional area of the gas inlet 21 of the fifth modification is set to be the same size as or larger than the flow path cross-sectional area of the outlet 23.

1 Internal combustion engine 2 Engine body 3 Cooling fan 10 Blow-by gas pipe (blow-by gas passage)
10a Downstream end 20 Atmosphere open pipe 20a Main body 21 Gas inlet 22 Air inlet 23 Outlet 100 Blow-by gas treatment device B Blow-by gas W Wind

Claims (5)

It is a blow-by gas processing device for internal combustion engines.
The internal combustion engine includes an engine body and a cooling fan for cooling the engine body.
The blow-by gas treatment device is
The blow-by gas passage through which blow-by gas flows and the blow-by gas passage
It is provided at the downstream end of the blow-by gas passage and is provided with an atmospheric opening pipe for opening the blow-by gas to the atmosphere.
The atmospheric release pipe is
A gas inlet that introduces blow-by gas from the blow-by gas passage,
An air inlet that introduces the air sent from the cooling fan,
It has an outlet for discharging blow-by gas introduced from the gas inlet into the atmosphere together with the wind introduced from the air inlet.
The air inlet is arranged so as to face the wind sent from the cooling fan.
A blow-by gas processing apparatus characterized in that the flow path cross-sectional area of the outlet is smaller than the flow path cross-sectional area of the air inlet. The atmospheric release tube comprises a tubular body extending axially.
The air inlet is formed by one end of the body and directed towards the cooling fan.
The outlet is formed by the other end of the body and directed towards the opposite side of the air inlet.
The blow-by gas treatment device according to claim 1, wherein the gas inlet is formed in the main body portion located between the air inlet and the outlet. The blow-by gas treatment apparatus according to claim 2, wherein the flow path cross-sectional area of the main body is gradually reduced from the air inlet to the outlet. The gas inlet is formed in a tubular shape protruding radially outward from the main body portion.
The blow-by gas treatment device according to claim 2 or 3, wherein the atmospheric release pipe is formed in a T shape. The air inlet is formed in a round hole shape.
The blow-by gas treatment apparatus according to any one of claims 1 to 4, wherein the outlet is formed in a round hole shape, a vertically long hole shape, or a horizontally long hole shape.

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