JP2024068623A - Exhaust system parts - Google Patents

Abstract

[Problem] To provide an exhaust system part that can share a sensor boss. [Solution] One aspect of the present disclosure is an exhaust system part including a tube body and a sensor boss attached to the tube body. The tube body has an inclined portion having an outer surface that intersects with the flow direction of exhaust gas, and a boss insertion hole provided in an area including the inclined portion. The sensor boss has a cylindrical boss body inserted into the boss insertion hole, and a protruding portion that protrudes from the outer circumferential surface of the boss body radially outward of the boss body. The protruding portion extends from a first end of the boss body in the flow direction of exhaust gas along the circumferential direction of the boss body, and does not reach a second end of the boss body opposite to the first end in the flow direction of exhaust gas. The extension direction of the protruding portion is inclined with respect to an imaginary plane that is perpendicular to the central axis of the boss body. [Selected Figure] Figure 1

Description

This disclosure relates to exhaust system components.

A sensor for checking the components of the exhaust gas is placed in the exhaust system components through which the exhaust gas from the internal combustion engine flows. This sensor is attached to the tube body of the exhaust system component via a sensor boss (see Patent Document 1).

The sensor boss is designed to fit the shape of the pipe where the sensor is to be installed (i.e., where the measurement is to be performed).

JP 2021-134765 A

If the location where the sensor is to be installed includes an outer surface that intersects with the flow direction, such as a tapered or stepped portion of the pipe, a sensor boss that matches the location where the sensor is to be installed is required. This requires that a dedicated sensor boss be prepared for each exhaust system part, which increases the manufacturing costs of the exhaust system parts.

One aspect of the present disclosure aims to provide exhaust system components that can share a common sensor boss.

One aspect of the present disclosure is an exhaust system component that includes a tube configured to allow exhaust gas from an internal combustion engine to flow therethrough, and a sensor boss attached to the tube. The tube has an inclined portion having an outer surface that intersects with the flow direction of the exhaust gas, and a boss insertion hole provided in a region of the tube that includes the inclined portion.

The sensor boss has a cylindrical boss body inserted into the boss insertion hole, and a protrusion that protrudes radially outward from the outer peripheral surface of the boss body and is disposed on the outside of the tube. The protrusion extends from a first end of the boss body in the exhaust gas flow direction along the circumferential direction of the boss body, and does not reach a second end of the boss body opposite the first end in the exhaust gas flow direction. The extension direction of the protrusion is inclined with respect to an imaginary plane perpendicular to the central axis of the boss body.

With this configuration, the sensor boss can be positioned with respect to the inclined portion of the pipe by inserting the sensor boss into the boss insertion hole while the protrusion is in contact with the edge of the boss insertion hole. Also, the welding direction between the boss body and the pipe can be adjusted in the portion of the boss body where the protrusion is not provided. Therefore, the sensor boss can be attached to the inclined portion regardless of the shape of the inclined portion. As a result, the sensor boss can be shared between exhaust system parts that have different shapes of the part where the sensor is attached.

In one aspect of the present disclosure, the central axis of the boss body may intersect with an imaginary plane perpendicular to the flow direction of the exhaust gas. This configuration makes it easier to insert the boss body into the boss insertion hole.

In one aspect of the present disclosure, the protrusion may contact the edge of the boss insertion hole. This configuration makes it easier to join the sensor boss and the tube body.

One aspect of the present disclosure may further include a purification member disposed inside the tube. The boss insertion hole may be disposed upstream or downstream of the purification member in the exhaust gas flow direction. With this configuration, it is possible to monitor the components of the exhaust gas upstream or downstream of the purification member.

FIG. 1 is a schematic diagram of an exhaust system component according to an embodiment. 2A and 2B are schematic enlarged partial views of the periphery of a sensor boss in the exhaust system component of FIG. 1. FIG. FIG. 3 is a schematic cross-sectional end view taken along line III-III in FIG. 2B. 4A is a schematic front view of the sensor boss of FIG. 2A, and FIG. 4B is a schematic plan view of the sensor boss of FIG. 2A. 5A is a schematic front view of a sensor boss in an embodiment different from that in FIG. 4A, and FIG. 5B is a schematic partial cut-away end view of a sensor boss in an embodiment different from that in FIG. 4A. 6A, 6B and 6C are schematic partial cutaway end views of sensor bosses in different embodiments than that of FIG. 4A. FIG. 7 is a schematic cross-sectional end view of the periphery of a sensor boss in an embodiment different from that in FIG.

Hereinafter, embodiments to which the present disclosure is applied will be described with reference to the drawings.
[1. First embodiment]
[1-1. Configuration]
1 is an exhaust gas purification device that is provided in an exhaust gas flow path of an internal combustion engine and reduces environmental pollutants in the exhaust gas. The exhaust system part 1 includes a pipe body 2, an upstream connection part 3, a downstream connection part 4, a first purification member 5, a second purification member 6, and a sensor boss 7.

The internal combustion engine in which the exhaust system component 1 is installed is not particularly limited. Examples of internal combustion engines include those used for driving or generating electricity in transportation equipment such as automobiles, trains, ships, and construction machines, and power generation facilities.

<Tube>
The pipe body 2 is a cylindrical member through which the exhaust gas G flows in the axial direction. The pipe body 2 has a first cylindrical portion 21, a second cylindrical portion 22, an inclined portion 23, and a boss insertion hole 24.

The first cylindrical portion 21 is disposed upstream of the second cylindrical portion 22. The first cylindrical portion 21 holds the first purification member 5. The second cylindrical portion 22 has an inner diameter larger than that of the first cylindrical portion 21. The second cylindrical portion 22 holds the second purification member 6.

The inclined portion 23 is a truncated cone-shaped cylinder that connects the first cylindrical portion 21 and the second cylindrical portion 22 in the flow direction of the exhaust gas G (i.e., the axial direction of the tube body 2). The inclined portion 23 expands linearly in diameter toward the downstream side in the flow direction of the exhaust gas G (i.e., toward the second cylindrical portion 22). The inclined portion 23 has an inner surface and an outer surface that intersect with the flow direction of the exhaust gas G.

The boss insertion hole 24 is a hole into which the sensor boss 7 is inserted. The boss insertion hole 24 is provided in a region of the tube body 2 that includes the inclined portion 23. Specifically, the boss insertion hole 24 is provided across the first tubular portion 21 and the inclined portion 23.

In other words, the boss insertion hole 24 is provided in a region including the inclined portion 23 and a portion upstream of the inclined portion 23 whose outer surface is parallel to the flow direction of the exhaust gas G. In addition, the boss insertion hole 24 is disposed downstream of the first purification member 5 and upstream of the second purification member 6 in the flow direction of the exhaust gas G.

<Upstream connection>
The upstream connection part 3 connects the pipe body 2 to the exhaust gas flow path. The upstream connection part 3 is connected to the upstream end of the first cylindrical part 21. The exhaust gas G is supplied from the upstream connection part 3 to the pipe body 2.

<Downstream connection>
The downstream connection part 4 connects the pipe body 2 to the exhaust gas flow passage on the opposite side to the upstream connection part 3. The downstream connection part 4 is connected to the downstream end of the second cylindrical part 22. The exhaust gas G is discharged from the pipe body 2 to the downstream connection part 4.

<Purification components>
The first purification member 5 is disposed inside the first cylindrical portion 21. The second purification member 6 is disposed inside the second cylindrical portion 22.

The first purification member 5 and the second purification member 6 are configured to modify or capture environmental pollutants in the exhaust gas. Here, "environmental pollutants" refers to carbon monoxide (CO), nitrogen oxides (NOx), particulate matter (PM), sulfur oxides (SOx), hydrocarbons (HC), etc.

Examples of the first purification member 5 and the second purification member 6 include a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), a gasoline particulate filter (GPF), a NOx adsorbent, etc.

DOC is a catalyst that oxidizes soluble organic matter (SOF), CO, and HC in the PM contained in exhaust gas. DPF and GPF are filters that collect PM contained in exhaust gas. NOx adsorbent is a substance that adsorbs and removes NOx.

The first purification member 5 and the second purification member 6 are different types of purification members. The first purification member 5 and the second purification member 6 have different shapes. However, the same type of purification member may be used as the first purification member 5 and the second purification member 6.

No purification member is disposed in the inclined portion 23. In other words, in the flow direction of the exhaust gas G, there is a space between the first purification member 5 and the second purification member 6 in which no purification member is disposed. The boss insertion hole 24 connects this space to the outside of the tube body 2.

<Sensor boss>
The sensor boss 7 is a component for mounting a sensor (not shown) for measuring exhaust gas parameters such as the concentration of components to be measured (e.g., NOx, PM, etc.) in the exhaust gas G and the exhaust gas pressure.

As shown in Figures 2A and 2B, the sensor boss 7 is attached to the boss insertion hole 24 of the tube body 2. The sensor boss 7 has a boss body 71 and a protrusion 72.

The boss body 71 is a cylindrical member inserted into the boss insertion hole 24. The outer peripheral surface of the boss body 71 is in contact with or close to the edge of the boss insertion hole 24. A sensor is inserted into the internal space of the boss body 71. The tip of the sensor is positioned inside the tube body 2 (specifically, inside the inclined portion 23).

The central axis P of the boss body 71 intersects at an angle α with a first imaginary plane S1 that is perpendicular to the flow direction of the exhaust gas G. In other words, the central axis P of the boss body 71 is inclined with respect to both the flow direction of the exhaust gas G (i.e., the axial direction of the tube body 2) and the radial direction of the tube body 2.

As shown in FIG. 3, the inner circumferential surface of the boss body 71 is provided with a threaded portion 715 for mounting a sensor. The threaded portion 715 is provided along the entire axial direction of the boss body 71.

As shown in Figures 4A and 4B, the protrusion 72 is a flange-shaped portion that protrudes radially outward from the outer circumferential surface of the boss body 71. The protrusion 72 is composed of a convex portion that extends from a first end 711 of the boss body 71 upstream in the flow direction of the exhaust gas G to both sides along the circumferential direction of the boss body 71.

The protrusion 72 does not reach the second end 712 of the boss body 71, which is opposite (i.e., downstream of) the first end 711 in the flow direction of the exhaust gas G. As shown in FIG. 4A, the protrusion 72 is provided on the entire area of the outer circumferential surface of the boss body 71 that is upstream of the central axis P of the boss body 71 (i.e., upward in FIG. 4A) when viewed from the axial direction of the boss body 71.

In addition, both ends of the protrusion 72 reach the area of the outer circumferential surface of the boss body 71 downstream of the central axis P of the boss body 71. In other words, a smooth portion with a constant outer diameter in the axial direction of the boss body 71 is provided in the area downstream of the central axis P of the boss body 71 in the flow direction of the exhaust gas G.

The protrusion 72 has a shape that is plane-symmetrical with respect to a second imaginary plane S2 that includes the central axis P of the boss body 71 and is parallel to the flow direction of the exhaust gas G. The second imaginary plane S2 passes through the central axis P of the protrusion 72 and the central portion 721.

Therefore, both ends of the protrusion 72 are at the same position in the flow direction of the exhaust gas G. When viewed from the axial direction of the boss body 71, the central angle θ of the arc portion of the outer circumferential surface of the boss body 71 where the protrusion 72 is provided is equal to or greater than 10° and equal to or less than 350°.

As shown in FIG. 4B, the extension direction of the protrusion 72 (i.e., the center line L) is inclined with respect to a third imaginary plane S3 that is perpendicular to the central axis P of the boss body 71. Specifically, the center line L of the protrusion 72 is smoothly curved such that the central portion 721 of the protrusion 72 that overlaps with the first end portion 711 of the boss body 71 is convex toward the outside of the tube body 2.

However, the center line L of the protrusion 72 may be V-shaped with the center portion 721 as the base. In other words, the center line L of the protrusion 72 may be composed of straight lines and bending points.

The central portion 721 is the portion of the protrusion 72 that is closest to the outer end 713 of the boss body 71 in the axial direction of the boss body 71. The central portion 721 contacts the uppermost point of the boss insertion hole 24.

The outer end 713 of the boss body 71 is an axial end portion that is located on the outside of the tube body 2. Both ends of the protrusion 72 in the extension direction are closer to the inner end 714 of the boss body 71 than the central portion 721. The inner end 714 of the boss body 71 is an axial end portion that is located on the inside of the tube body 2.

As shown in FIG. 3, in a cross section including the central axis P of the boss body 71, the protruding end of the protruding portion 72 is curved so as not to have a corner (for example, in a semicircular arc shape). In addition, it is preferable that the width of the protruding portion 72 in a direction perpendicular to the extension direction is approximately constant. It is preferable that the thickness of the protruding portion 72 in the axial direction of the boss body 71 is approximately the same as the thickness of the wall of the first tubular portion 21.

As shown in FIG. 2A, the protrusion 72 contacts the edge of the boss insertion hole 24 from the outside of the tube body 2 (specifically, the first tubular portion 21). The protrusion 72 is joined to the outer circumferential surface of the tube body 2 by, for example, welding.

In this embodiment, the protrusion 72 overlaps only the first tubular portion 21 (i.e., the portion whose outer surface is parallel to the flow direction of the exhaust gas G) in the axial direction of the protrusion 72 (i.e., the insertion direction of the boss body 71), and does not overlap the inclined portion 23.

<Modifications of the sensor boss>
As shown in Fig. 5A, the boss body 71 may have a flat portion 716. The flat portion 716 is a portion having a surface perpendicular to the radial direction of the boss body 71. The boss body 71 in Fig. 5A has a shape in which a part of a cylinder is cut out along a surface parallel to the central axis.

The flat portion 716 includes the second end 712 of the boss body 71. The protruding portion 72 is not provided on the flat portion 716. The flat portion 716 makes it easy to position the boss body 71 relative to the boss insertion hole 24.

As shown in FIG. 5B, the threaded portion 715 may be provided only in a portion of the boss body 71 in the axial direction (specifically, the outside of the tube body 2). Also, as long as a sensor can be attached, the boss body 71 does not necessarily have to be provided with the threaded portion 715.

As shown in FIG. 6A, the protruding end of the protruding portion 72 may have a corner. Also, as shown in FIG. 6B, the protruding end of the protruding portion 72 may have a step. Furthermore, as shown in FIG. 6C, the protruding portion 72 may reach the outer end 713 of the boss body 71.

[1-2. Action]
The procedure for attaching the sensor boss 7 and the sensor to the pipe body 2 of the exhaust system component 1 will be described below.

First, the sensor boss 7 is inserted into the boss insertion hole 24 with the first end 711 of the boss body 71 located upstream of the tube 2 relative to the second end 712 and the inner end 714 located inside the tube 2. At this time, the sensor boss 7 is inserted into the boss insertion hole 24 while rotating around its axis so that the protruding portion 72 contacts the edge of the boss insertion hole 24.

This determines the position of the sensor boss 7 in the flow direction of the exhaust gas G, the position in the axial direction of the boss body 71 (i.e., the insertion position), and the orientation of the sensor boss 7 (i.e., the rotation angle around the central axis P of the boss body 71).

After the sensor boss 7 is inserted, the protruding portion 72 is welded to the outer peripheral surface of the first tubular portion 21, and then the outer peripheral surface of the boss body 71 is welded to the outer peripheral surface of the inclined portion 23, thereby attaching the sensor boss 7 to the tube body 2. After attaching the sensor boss 7, the sensor is attached to the boss body 71.

In this embodiment, if the shape (i.e., taper angle) of the inclined portion 23 changes due to, for example, a change in the purification member, the sensor boss 7 can be attached to the pipe body 2 by changing the welding position between the outer circumferential surface of the boss body 71 and the outer circumferential surface of the inclined portion 23. Therefore, there is no need to change the shape of the sensor boss 7 to match the inclined portion 23.

[1-3. Effects]
According to the embodiment described above in detail, the following effects can be obtained.
(1a) By inserting the sensor boss 7 into the boss insertion hole 24 while bringing the protruding portion 72 into contact with the edge of the boss insertion hole 24, the sensor boss 7 can be positioned with respect to the inclined portion 23 of the pipe body 2. Furthermore, the protruding portion 72 suppresses the movement of the sensor boss 7 in a direction intersecting with the exhaust gas G.

In addition, the welding direction between the boss body 71 and the pipe body 2 can be adjusted in the portion of the boss body 71 where the protrusion 72 is not provided. Therefore, the sensor boss 7 can be attached to the inclined portion 23 regardless of the shape of the inclined portion 23. As a result, the sensor boss 7 can be shared between exhaust system components that have different shapes of the portion where the sensor is attached.

(1b) The central axis P of the boss body 71 intersects with the first imaginary plane S1, making it easier to insert the boss body 71 into the boss insertion hole 24.
(1c) The protrusion 72 comes into contact with the edge of the boss insertion hole 24, making it easier to join the sensor boss 7 and the pipe body 2.

(1d) The boss insertion hole 24 is disposed downstream of the first purification member 5 and upstream of the second purification member 6 in the flow direction of the exhaust gas G, so that the components of the exhaust gas G downstream of the first purification member 5 and upstream of the second purification member 6 can be monitored.

2. Other embodiments
Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above-described embodiments and can take various forms.

(2a) In the exhaust system components of the above embodiments, the central axis of the boss body does not necessarily have to intersect with the first imaginary plane. For example, the central axis of the boss body may be perpendicular to the flow direction of the exhaust gas.

(2b) In the exhaust system components of the above embodiments, the protrusion does not necessarily have to contact the edge of the boss insertion hole. For example, the protrusion may move away from the edge of the boss insertion hole after the sensor boss is positioned.

(2c) In the exhaust system components of the above embodiment, the boss insertion hole does not necessarily have to be located upstream or downstream of the purification member. In addition, the exhaust system component does not necessarily have to include a purification member. The boss insertion hole may be provided in a portion of the exhaust system component other than the pipe body (e.g., the upstream connection portion, the downstream connection portion, etc.).

(2d) In the exhaust system components of the above embodiments, the inclined portion does not necessarily have to expand in diameter linearly. For example, as shown in FIG. 7, the boss insertion hole 24 may be provided in the inclined portion 23 whose outer surface is curved. In FIG. 7, the boss insertion hole 24 is provided in an area that includes only the inclined portion 23.

The inclined portion may be a portion whose diameter decreases toward the downstream side, or a portion whose outer surface extends parallel to the radial direction of the pipe (i.e., a step portion). Furthermore, the boss insertion hole may be provided in a region that includes the inclined portion and a portion downstream of the inclined portion.

(2e) In the exhaust system component of the above embodiment, the first end portion, which is the starting point of the protrusion, may be the downstream end portion in the flow direction of the exhaust gas. In other words, the protrusion portion may extend from the downstream end portion along the circumferential direction of the boss body, and may have a shape that does not reach the upstream end portion.

(2f) The function of one component in the above embodiments may be distributed among multiple components, or the functions of multiple components may be integrated into one component. In addition, part of the configuration of the above embodiments may be omitted. In addition, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments. All aspects included in the technical idea identified from the wording of the claims are embodiments of the present disclosure.

1... exhaust system part, 2... pipe body, 3... upstream connection part, 4... downstream connection part, 5... first purification member,
6: second cleaning member; 7: sensor boss; 21: first cylindrical portion; 22: second cylindrical portion;
23: Inclined portion; 24: Boss insertion hole; 71: Boss body; 72: Protrusion;
711: first end, 712: second end, 713: outer end, 714: inner end,
715...threaded portion, 716...flat portion.

Claims (4)

A pipe body configured to allow exhaust gas from an internal combustion engine to flow therethrough;
a sensor boss attached to the tube;
Equipped with
The tube is
an inclined portion having an outer surface intersecting the flow direction of the exhaust gas;
a boss insertion hole provided in a region of the pipe body including the inclined portion;
having
The sensor boss is
a cylindrical boss body inserted into the boss insertion hole;
a protrusion protruding from an outer circumferential surface of the boss body toward an outer side in a radial direction of the boss body and disposed outside the tube;
having
the protrusion extends from a first end of the boss body in the exhaust gas flow direction along a circumferential direction of the boss body, and does not reach a second end of the boss body opposite to the first end in the exhaust gas flow direction,
an extension direction of the protrusion is inclined with respect to an imaginary plane perpendicular to a central axis of the boss body; 2. An exhaust system component according to claim 1,
An exhaust system component, wherein a central axis of the boss body intersects with an imaginary plane perpendicular to a flow direction of the exhaust gas. 3. An exhaust system component according to claim 1 or 2,
The protrusion contacts an edge of the boss insertion hole. 3. An exhaust system component according to claim 1 or 2,
Further comprising a cleaning member disposed inside the tube,
The boss insertion hole is disposed upstream or downstream of the purification member in a flow direction of the exhaust gas.