DE102020208537A1 - Exhaust duct structure of an engine - Google Patents

Abstract

[Object] To provide an exhaust passage structure of an internal combustion engine capable of preventing the damage of an exhaust gas sensor and improving the detection accuracy of the exhaust gas sensor. [Solution] A communication passage forming member (32) that constitutes a communication passage (32A) that from an exhaust outlet (20C) of a turbine casing (20A) and extending downward is provided between the exhaust outlet (20C) and a catalyst (30C), and the connecting passage forming member (32) includes a wall portion (32C) the side opposite a center of curvature (C) of the connecting channel (32A). The wall portion (32C) includes a first flat portion (32D) inclined so as to deviate from an upper side to a lower side of the turbine casing (20A), a curved portion (32E) of a lower end portion of the first flat portion Section (32D), and a second flat section (32F) which is connected to the first flat section (32D) via the curved section (32E) and which extends outward relative to an extension surface (E) of the first flat section (32D) and an exhaust gas sensor (35) is provided in the second flat portion (32F).

Description

[Technical area]

The present invention relates to an exhaust passage structure of an engine.

[Background of the Invention]

Conventionally, among vehicles such as an automobile, there is known a vehicle in which a turbine casing of a turbocharger and a catalyst are arranged in series in an exhaust gas flow direction along an exhaust passage, and the exhaust passage is provided with a bypass passage for bypassing a turbine wheel of the turbocharger (see FIG JP 2012-241545 A ).

The in JP 2012-241545 A An exhaust gas sensor, such as an air-fuel ratio sensor or an oxygen sensor, is arranged in the passage between the turbocharger and the turbine housing of the turbocharger, and to improve the accuracy of the detection of the imbalance of the air-fuel ratio between the cylinders improve, the exhaust gas flowing through the diversion channel is directed in such a way that it hits the exhaust gas sensor directly.

[Summary of the invention]

[Task to be solved]

At the in JP 2012-241545 A However, the technique described, the exhaust gas is directed so that it hits the exhaust gas sensor directly. For this reason, since the temperature of the exhaust gas sensor becomes locally high when the exhaust gas intensely hits a position of the exhaust gas sensor, the exhaust gas sensor may be damaged by overheating. Since the condensed water generated in the exhaust gas also hits the exhaust gas sensor directly, there is a risk that the exhaust gas sensor could be damaged by contact with the condensed water.

On the other hand, the detection accuracy of the exhaust gas sensor could deteriorate, for example, if the exhaust gas sensor is arranged in such a way that it is largely separated from the flow path of the exhaust gas in order to prevent the damage.

This invention has been made in view of the above-described circumstances, and the object is to provide an exhaust passage structure of an internal combustion engine capable of preventing the deterioration of an exhaust gas sensor and improving the detection accuracy of the exhaust gas sensor.

[Means of solving the problem]

According to aspects of this invention, an exhaust passage structure of an internal combustion engine is provided in which a turbine housing of a turbocharger and a catalyst are provided in series in an exhaust gas flow direction in an exhaust passage of an internal combustion engine, in which a connection passage-forming element that forms a connection passage from an exhaust outlet of the turbine housing is curved and extends downward, is provided between the exhaust outlet and the catalyst in the exhaust passage, in which the connection passage-forming element has a wall portion which is provided with an exhaust gas sensor on the side opposite to a center of curvature of the connection passage, in which the wall portion has a first includes a flat portion disposed in a portion facing the exhaust outlet and inclined so as to deviate from an upper side to a lower side of the turbine casing, a curved portion that is at a lower end portion of the first flat portion is curved outward, and a second flat portion which is connected via the curved portion to the first flat portion and extends outward relative to an extension surface of the first flat portion, and in which the exhaust gas sensor in the second flat section is provided.

[Effect of the invention]

In this way, according to the present invention, it is possible to provide an exhaust passage structure of an internal combustion engine capable of preventing damage to an exhaust gas sensor and improving the detection accuracy of the exhaust gas sensor.

Figure list

• [ 1 ] 1 Fig. 13 is a left side view of an internal combustion engine having an exhaust passage structure according to an embodiment of the present invention.
• [ 2 ] 2 Figure 13 is a plan view of an internal combustion engine having an exhaust passage structure according to an embodiment of the present invention.
• [ 3 ] 3 Fig. 14 is a left side view of an upper part of an exhaust gas purification device of an internal combustion engine having an exhaust passage structure according to an embodiment of the present invention.
• [ 4th ] 4th Fig. 13 is a left side view showing an internal structure of an upper part of an exhaust gas purification device of an internal combustion engine having an exhaust passage structure according to the embodiment of the present invention.
• [ 5 ] 5 FIG. 13 is a cross-sectional view from a direction VV of FIG 1 .

[Embodiment (s) of the invention]

According to embodiments of the present invention, an exhaust passage structure of an internal combustion engine is provided in which a turbine casing of a turbocharger and a catalyst are provided in series in an exhaust gas flow direction in an exhaust passage of an internal combustion engine, in which a connection passage forming element that forms a connection passage leading from an exhaust outlet of the Turbine housing is curved and extends downward, is provided between the exhaust outlet and the catalyst in the exhaust passage, in which the connection passage-forming element has a wall portion which is provided with an exhaust gas sensor on the side opposite to a center of curvature of the connection passage, in which the wall portion has a comprises a first flat portion disposed in a portion facing the exhaust outlet and inclined so as to deviate from an upper side to a lower side of the turbine casing, a curved absc h section curved outward at a lower end portion of the first flat portion, and a second flat portion connected to the first flat portion via the curved portion and extending outward relative to an extension surface of the first flat portion, and at which the exhaust gas sensor is provided in the second flat portion. Accordingly, the exhaust passage structure of the internal combustion engine according to the embodiments of the present invention can prevent damage to the exhaust gas sensor and improve the detection accuracy of the exhaust gas sensor.

[Embodiments]

Next, an exhaust passage structure of an internal combustion engine according to an embodiment of the present invention will be described with reference to the drawings. The 1 to 5 14 are schematic diagrams illustrating an internal combustion engine having an exhaust passage structure according to an embodiment of the present invention. In the 1 to 5 the up, down, forward, backward, left and right directions are the up, down, forward, backward, left and right directions of the internal combustion engine installed in the vehicle, the direction perpendicular to the forward / backward direction is the left / right direction and the height direction of the motor is the up / down direction.

First, a configuration will be described. In 1 includes an internal combustion engine 1 an engine body 10 and equipment which will be described later and which are installed in the engine body 10. The internal combustion engine 10 comprises a cylinder block 11, a cylinder head 12, a cylinder head cover 13 and an oil pan 14 for storing the lubricating oil.

The cylinder block 11 is provided with a plurality of cylinders 10A (see FIG 2 ). In the following, the arrangement direction of the plurality of cylinders 10A is also referred to as the cylinder row direction. The internal combustion engine 1 This embodiment is configured as a four-cylinder engine having four cylinders 10A, but is not limited to the four-cylinder engine.

The cylinder 10A receives a piston (not shown), and the piston reciprocates with respect to the cylinder in an up and down direction, respectively.
The piston is connected via a connecting rod (not shown) to a crankshaft 11A (see 1 ) and the reciprocating motion of the piston is converted into the rotating motion of the crankshaft 11A by the connecting rod.

In 2 A chain case 15 is attached to the right end portions of the cylinder block 11 and the cylinder head 12 in the cylinder row direction. The chain case 15 covers a timing chain (not shown) arranged in the right end portions of the cylinder block 11 and the cylinder head 12.

Here the cylinder row direction corresponds to the internal combustion engine 1 the left and right directions, that is, the vehicle width direction. The internal combustion engine 1 is thus arranged in a vehicle (not shown) in a so-called horizontal posture.

The cylinder head 12 is provided with a plurality of intake ports 61, 62, 63 and 64 which are respectively communicated with the plurality of cylinders 10A. The plurality of intake ports 61, 62, 63 and 64 are arranged side by side in the cylinder row direction.

Further, the cylinder head 12 is provided with an intake valve, a plurality of exhaust ports and a plurality of exhaust valves for opening or closing the exhaust ports, which are not shown in the drawings.

A rear surface of the cylinder head 12 is provided with an intake manifold 40, and the intake manifold 40 guides intake air into each cylinder 10A through inlet ports 61, 62, 63 and 64.

An exhaust manifold (not shown) is formed inside the cylinder head 12. The exhaust manifold includes a plurality of exhaust ports (not shown) each communicating with the cylinders 10A, and collects an exhaust gas (also referred to as exhaust gas) exiting the cylinder 10A. That is, the exhaust manifold integrated with the exhaust port is formed inside the cylinder head 12.

The exhaust manifold includes a common collective exhaust outlet (not shown). The collective exhaust outlet opens to an end face of the cylinder head 12 at the central portion in the cylinder row direction.

The exhaust gas exiting the cylinder 10A is collected by the exhaust manifold and discharged from the collective exhaust gas outlet to the outside of the cylinder head 12.

In 1 and 2 is a turbocharger on the end face side of the cylinder head 12 20th provided, which is a compressor. The turbocharger 20th includes a turbine housing 20A , through which the exhaust gas flows, and a compressor housing 20B, through which the intake air of the internal combustion engine 1 is flowed through. The upstream end of the turbine housing exhaust duct 20A is connected to an exhaust manifold.

The turbocharger 20th compresses the intake air with the aid of the compressor housing 20B using the energy from the exhaust gas collection outlet into the turbine housing 20A introduced exhaust gas. The one from the turbocharger 20th Compressed air is introduced into the intake manifold 40.

An exhaust gas purification device 30 is on the left side of the turbocharger 20th and the exhaust gas purifying device 30 extends upward and downward at the left end portion of the end face side of the internal combustion engine 10.

The downstream end of the turbocharger exhaust duct 20th is connected to an upper end portion 30A of the exhaust gas purification device 30.

A catalyst 30C and a particulate filter 30D are housed inside the exhaust gas purification device 30 at a position shown in FIG 1 indicated by a dashed line. The catalyst 30C Simultaneously cleans HC, CO and NOx contained in the exhaust gas through an oxidation and reduction reaction. That way is the catalyst 30C a three way catalyst. The particle filter 30D is on the downstream side of the catalyst 30C is provided and collects graphite, unburned fuel (SOF: flammable organic substances), engine oil ash (oil ash) and the like as particles (PM), which correspond to particles contained in the exhaust gas.

An exhaust pipe (not shown) is connected to a lower end portion 30B of the exhaust purification device 30. The exhaust gas that runs the turbocharger 20th has passed through, is cleaned in the exhaust gas purification device 30 and discharged through the exhaust pipe to the outside of the vehicle.

In 1 and 2 the intake manifold 40 includes a surge tank (not shown) extending in the cylinder row direction and a plurality of branch pipes. Each branch pipe has a convex shape curved upward from the surge tank toward the cylinder head 12, and its downstream ends are connected to the inlet ports 61, 62, 63 and 64 of the rear side of the cylinder head 12 in an arrangement order in the cylinder row direction, respectively.

In the combustion engine 1 a throttle body 23 is provided in the left end portion of the pressure equalization tank of the intake manifold 40. The throttle body 23 regulates the amount of air that flows into the intake ports 61, 62, 63, and 64 through the intake manifold 40.

The internal combustion engine 1 includes an exhaust gas recirculation pipe 21, an exhaust gas recirculation passage 12A formed in the cylinder head 12, a connecting pipe 22, and an EGR cooler 24.

The exhaust gas recirculation pipe 21 extends in the up / down direction along the left side surface of the exhaust gas purification device 30. The exhaust gas recirculation pipe 21 connects the exhaust gas outlet portion of the exhaust gas purification device 30 to the exhaust gas recirculation passage 12A, and introduces the exhaust gas purified by the exhaust gas purification device 30 into the exhaust gas recirculation passage 12A.

The connecting pipe 22 is disposed near the left end portion of the rear surface of the cylinder head 12, and connects the exhaust gas recirculation passage 12A to the EGR cooler 24.

The exhaust gas recirculation passage 12A extends inside the left side surface of the cylinder head 12 in the forward / backward direction and guides that introduced from the exhaust gas recirculation pipe 21 on the end face side of the cylinder head 12 Exhaust gas enters the connecting pipe 22 on the rear surface side of the cylinder head 12.

The internal combustion engine 1 includes an EGR valve 26 in the exhaust passage between the EGR cooler 24 and the intake manifold 40, and the exhaust gas cooled in the EGR cooler 24 is introduced into the intake manifold 40 after the flow rate through the EGR valve 26 is adjusted.

In 1 is the exhaust duct 1A of the internal combustion engine 1 with the turbine housing 20A of the turbocharger 20th and the catalyst 30C of the exhaust gas purifying device 30 provided in series in the exhaust gas flow direction. In addition, the exhaust duct is 1A a general term for the duct through which the exhaust gas from the internal combustion engine 1 flows, but the exhaust duct 1A in 1 denotes the exhaust passage within the exhaust gas purification device 30.

In 3 , 4th and 5 is between the exhaust outlet 20C of the turbine housing 20A and the catalyst 30C the exhaust gas purification device 30 in the exhaust duct 1A an element forming a connecting channel 32 provided, the one from the exhaust outlet 20C curved and downward connecting channel 32A forms (see 1 ).

In other words, the exhaust gas purification device 30 comprises a cylindrical catalyst housing 33 in which the catalyst 30C or the like is accommodated, and the element forming the connecting channel 32 , which is connected to the upstream side of the catalyst housing 33 in the exhaust gas flow direction. The element forming the connecting channel 32 includes the above-described upper end portion 30A. The element forming the connecting channel 32 has an overall shape in which a cylindrical portion extending in the exhaust gas blowing direction of the exhaust gas outlet 20C extends, and a conical portion whose diameter widens downward, are combined.

Furthermore, the element forming the connecting channel comprises 32 a wall section 32C , the one on the side opposite the center of the curvature C. of the connection channel 32A with the exhaust gas sensor 35 is provided. The wall section 32C includes a first flat section 32D , a curved section 32E , the one at the lower end portion of the first flat portion 32D outwardly curved, and a second flat portion 32F .

The first flat section 32D is arranged in a section that corresponds to the exhaust gas outlet 20C of the turbine housing 20A is facing. The section leading to the exhaust outlet 20C facing, denotes a portion that faces the direction of the exhaust outlet 20C blown exhaust gas is facing. Because of this, it collides from the exhaust outlet 20C blown exhaust gas with the first flat section 32D .

The first flat section 32D is inclined so that it goes from the top to the bottom of the turbine housing 20A away. For this reason that changes with the first flat section 32D colliding exhaust gas down its flow direction.

The second flat section 32F is about the curved section 32E with the first flat section 32D connected and extends outward (to the left) with respect to the extension surface E. of the first flat section 32D . Here means the inside or the outside of the element forming the connecting channel 32 the middle side or the outside of the flow passage in the connecting channel 32A flowing exhaust gas.

The exhaust gas sensor 35 is in the second flat section 32F intended. Furthermore is the exhaust gas sensor 35 on the outside of the extension surface E. of the first flat section 32D arranged, that is, on the side of the second flat portion 32F in relation to the extension area E. . For this reason, there is a front end portion 35A of the exhaust gas sensor 35 on the inside of the extension surface E. of the first flat section 32D not free.

There is also a lower edge portion 32L of the second flat section 32F with a lower outer peripheral portion 32G provided, which has a downwardly convex arc shape. In other words, here the downwardly convex arc shape means an arc shape in which the center of an arc is on the upper side. The element forming the connecting channel 32 includes a cylindrical portion 32H , which has a cylindrical shape that extends to the lower outer peripheral portion 32G connects.

Furthermore, the element forming the connecting channel is 32 connected to the cylindrical catalyst housing 33, the catalyst 30C in the cylindrical section 32H the lower end portion of the same. Then the exhaust gas sensor 35 near the lower outer peripheral part 32G in the second flat section 32F arranged.

In 5 is the exhaust outlet 20C on one end side (the right end side of 5 ) near the turbine housing 20A in the width direction of the member forming the communication channel 32 arranged. The width direction of the element forming the communication channel 32 means one direction (the left / right direction) perpendicular to the exhaust gas flow direction on the assumption that the exhaust gas flow direction is within the element forming the connecting channel 32 is generally a downward direction.

The exhaust gas sensor 35 is on the other end side (the left end side of 5 ) from the turbine housing 20A removed in the width direction of the element forming the connecting channel 32 arranged.

In includes the lower outer peripheral portion 32G an extension section 32J that is in relation to the top margin section 32K of the second flat section 32F outwards (in 3 to the left) in the width direction of the connecting duct 32A extends. This extension section 32J denotes a portion that extends relative to the end portion (the front end portion in 3 ) in the width direction (the front / back direction) of the top edge portion 32K of the second flat section 32F in the lower outer peripheral portion 32G extends further forward. Finally is the exhaust gas sensor 35 near the extension section 32J arranged.

As described above, according to the exhaust passage structure of the internal combustion engine of this embodiment, there is between the exhaust outlet 20C of the turbine housing 20A and the catalyst 30C in the exhaust duct that is the connecting duct 32 forming element 32 provided that the exhaust gas outlet 20C curved and downward connecting channel 32A forms. Furthermore, the element forming the connecting channel comprises 32 the wall section 32C , the one with the exhaust gas sensor 35 on the side opposite the center of the curvature C. of the connection channel 32A is provided.

The wall section further comprises 32C the first flat section 32D , which is arranged in a portion that corresponds to the exhaust outlet 20C of the turbine housing 20A facing and is inclined so that it is from the top to the bottom of the turbine housing 20A is directed away, the curved section 32E , the one at the lower end portion of the first flat portion 32D outwardly curved, and the second flat portion 32F that is about the curved section 32E with the first flat section 32D connected and related to the extension surface E. of the first flat section 32D extends outward. Finally, there is the exhaust gas sensor 35 in the second flat section 32F intended.

Because the first flat section 32D is arranged in a section that corresponds to the exhaust gas outlet 20C of the turbine housing 20A facing, and is inclined from the top to the bottom so that it is away from the turbine housing 20A removed, that is from the exhaust outlet 20C of the turbine housing 20A in the connection channel 32A Introduced exhaust gas in this way is mainly scattered downwards when it is, as in the 3 and 5 indicated by an arrow, with the first flat section 32D collides and then touches the exhaust gas sensor 35 .

Since the exhaust gas, which has a high flow velocity and a large flow rate, does not directly hit the exhaust gas sensor 35 local heating of the exhaust gas sensor can occur 35 be prevented. In addition, the exhaust gas can be monitored from all directions with the exhaust gas sensor 35 be brought into contact. This can improve the detection accuracy of the exhaust gas sensor 35 be improved.

In addition, the second is flat section 32F through the curved section 32E with the bottom of the first flat section 32D connected and extending with respect to the extension surface E. of the first flat section 32D outward. Finally, there is the exhaust gas sensor 35 in the second flat section 32F intended.

Because of this, it comes out of the exhaust outlet 20C of the turbine housing 20A escaping condensation water when entering the connecting duct 32A within the element forming the connecting channel 32 similar to the exhaust flow first with the first flat section 32D together. Then the condensed water flows along the surface of the first flat portion 32D down, is from the surface at the lower end portion of the first flat section 32D separated and falls down along the flow of the exhaust gas.

Since the condensation water does not match the exhaust gas sensor 35 that comes into contact in the second flat section 32F is provided which is in relation to the first flat section 32D extends outward, it is possible to prevent the exhaust gas sensor 35 exposed to condensation.

This makes it possible to damage the exhaust gas sensor 35 to prevent and the detection accuracy of the exhaust gas sensor 35 to improve.

According to the exhaust passage structure of the internal combustion engine of this embodiment, the lower edge portion is 32L of the second flat section 32F with the lower outer peripheral portion 32G provided which has a downwardly convex arc shape, and the element forming the connecting channel 32 includes the cylindrical portion 32H , which has a cylindrical shape that extends to the lower outer peripheral portion 32G connects. Finally, there is the exhaust gas sensor 35 near the lower outer peripheral portion 32G in the second flat section 32F arranged.

As the exhaust gas sensor 35 at one of the exhaust outlet 20C of the turbine housing 20A is arranged in a separate position, it is possible to monitor the influence of the exhaust gas heat on the exhaust gas sensor 35 to prevent.

In addition, part of the exhaust gas flows when it collides with the first flat portion 32D is scattered around the lower outer peripheral portion 32G as indicated by an arrow in 5 specified, and comes with the exhaust gas sensor 35 in contact.

For this reason, the detection accuracy of the exhaust gas sensor 35 can be improved because a sufficient amount of exhaust gas with the exhaust gas sensor 35 can be brought into contact.

According to the exhaust passage structure of the internal combustion engine of this embodiment, the exhaust gas outlet is 20C on one end side near the turbine housing 20A in the width direction of the member forming the communication channel 32 and the exhaust gas sensor 35 on the other, from the turbine housing 20A distal end side in the width direction of the connecting channel forming member 32 arranged.

As the exhaust outlet 20C of the turbine housing 20A and the exhaust gas sensor 35 can be positioned at separate positions, it is accordingly possible to control the influence of the exhaust gas heat and the condensed water on the exhaust gas sensor 35 to prevent further.

According to the exhaust passage structure of the internal combustion engine of this embodiment, the lower outer peripheral portion includes 32G the extension section 32J that is in relation to the top margin section 32K of the second flat section 32F in the width direction of the connecting channel 32A extends outward, and the exhaust gas sensor 35 is near the extension section 32J arranged.

Because the extension section 32J in the lower outer peripheral portion 32G of the second flat section 32F is provided, can in this way when the collision with the first flat portion 32D diffused exhaust gas from the outside around the lower outer peripheral portion 32G flow and with the exhaust gas sensor 35 get in touch.

While embodiments of this invention have been described, it is apparent that those skilled in the art could make changes without departing from the scope of this invention. It is intended that all such changes and equivalents be included in the appended claims.

List of reference symbols

1

Combustion engine,

1A

Exhaust duct,

20th

Turbocharger (compressor),

20A

Turbine housing,

20C

Exhaust outlet,

30C

Catalyst,

30D

Particle filter,

32

Element to form the connecting channel,

32A

Connection channel,

32C

Wall section,

32D

First flat section,

32E

Curved section,

32F

Second flat section,

32G

Lower outer peripheral portion,

32H

Cylindrical section,

32J

Extension section,

32K

Upper edge section,

32L

Lower margin,

35

Exhaust gas sensor,

C.

Center of curvature,

E.

Extension surface

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• JP 2012241545 A [0002, 0003, 0004]

Claims (4)

Exhaust duct structure of an internal combustion engine, wherein a turbine housing of a turbocharger and a catalyst are provided in series in an exhaust gas flow direction in an exhaust passage of an internal combustion engine, wherein a connection passage forming member that forms a connection passage that is curved from an exhaust outlet of the turbine housing and extends downward is provided between the exhaust outlet and the catalyst in the exhaust passage, wherein the connecting channel-forming element has a wall portion which is provided with an exhaust gas sensor on the side opposite to a center of curvature of the connecting channel, wherein the wall portion includes a first flat portion that is disposed in a portion that faces the exhaust outlet and is inclined so as to move away from an upper side to a lower side of the turbine housing, a curved portion that is adjacent to a lower End portion of the first flat portion is curved outward, and a second flat portion which is connected to the first flat portion via the curved portion and extends outward relative to an extension surface of the first flat portion, and wherein the exhaust gas sensor is provided in the second flat portion. Exhaust duct structure of the internal combustion engine according to Claim 1 wherein a lower edge portion of the second flat portion is provided with a lower outer peripheral portion which has a downwardly convex arc shape, wherein the member forming the connection channel has a cylindrical portion with a cylindrical shape which adjoins the lower outer peripheral portion, and wherein the exhaust gas sensor is disposed in the vicinity of the lower outer peripheral portion in the second flat portion. Exhaust duct structure of the internal combustion engine according to Claim 2 wherein the exhaust outlet is located on one end side near the turbine casing in a width direction of the communication passage forming member, and the exhaust gas sensor is located on the other end side away from the turbine casing in the width direction of the communication passage forming member. Exhaust duct structure of the internal combustion engine according to Claim 3 wherein the lower outer peripheral portion includes an extension portion that extends outward relative to an upper edge portion of the second flat portion in a width direction of the communication passage, and wherein the exhaust gas sensor is disposed in the vicinity of the extension portion.

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