JP2018105143A - Exhaust structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat retaining properties of an aftertreatment device of an exhaust gas flow passage.SOLUTION: An exhaust structure includes an exhaust gas flow passage 10 for guiding exhaust gas of an internal combustion engine to the atmosphere, and an aftertreatment device 11 disposed in the exhaust gas flow passage 10. The exhaust structure further includes a cylindrical holding part 12 for holding the aftertreatment device 11. An inner peripheral surface of the holding part 12 is brought into contact with an outer peripheral surface of the aftertreatment device 11, a sealed vacuum chamber R is formed between an outer peripheral surface of the holding part 12 and the inner peripheral surface of the holding part 12, and a heat insulating member 13 having a heat insulating function is provided in the sealed vacuum chamber R.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an exhaust structure that exhausts exhaust gas generated in an internal combustion engine.

  The exhaust gas generated in the internal combustion engine of the vehicle is processed by a post-processing device provided in the exhaust gas flow path before being discharged from the vehicle into the atmosphere. Examples of the aftertreatment device include an oxidation catalyst (DOC: Diesel Oxidation Catalyst), DPF (Diesel Particulate Filter), or urea SCR (Selective Catalytic Reduction) when the internal combustion engine is a diesel engine.

  For example, in Patent Document 1, in the exhaust gas flow path, a sealed chamber containing a heat storage member and a vacuum heat insulating chamber covering the sealed chamber are provided on the upstream side of the catalyst (an example of a post-processing device). A structure for improving heat retention is disclosed.

JP 2003-314265 A

  However, since the flow rate of the exhaust gas flowing upstream of the catalyst is fast, the structure of Patent Document 1 cannot sufficiently retain the exhaust gas. Therefore, the structure of Patent Document 1 has room for improvement in the heat retention of the catalyst.

  The objective of this invention is providing the exhaust structure which can improve the heat retention of the aftertreatment apparatus of an exhaust gas flow path more.

  The exhaust structure of the present invention is an exhaust structure that includes an exhaust gas channel that guides exhaust gas of an internal combustion engine into the atmosphere, and an aftertreatment device that is disposed in the exhaust gas channel, and holds the aftertreatment device. It has a cylindrical holding part, the inner peripheral surface of the holding part is in contact with the outer peripheral surface of the post-processing apparatus, and between the outer peripheral surface of the holding part and the inner peripheral surface of the holding part, A vacuum sealed chamber is formed, and the sealed chamber is provided with a heat retaining member having a heat retaining function.

  According to the present invention, it is possible to further improve the heat retention of the exhaust gas passage aftertreatment device.

The figure which shows the structural example of the exhaust structure which concerns on embodiment of this invention The figure which shows the structural example of the exhaust structure which concerns on the modification of this invention

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The configuration of the exhaust structure according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing a configuration example of an exhaust structure according to the present embodiment, and shows a side cross section of an exhaust gas passage.

  As shown in FIG. 1, the exhaust structure includes an exhaust gas flow path 10, a post-processing device 11, a holding unit 12, and a heat retaining member 13.

  The exhaust gas passage 10 is a passage that guides exhaust gas generated in an internal combustion engine (not shown) to the atmosphere (outside the vehicle). The exhaust gas channel 10 is, for example, a cylindrical pipe. Each arrow shown in FIG. 1 indicates the direction in which the exhaust gas flows.

  The post-processing device 11 is disposed in the exhaust gas flow channel 10 and is held by a holding unit 12 described later. Examples of the post-processing device 11 include an oxidation catalyst (DOC), a DPF (Diesel Particulate Filter), a GPF (Gasoline Particulate Filter), and a urea SCR (Selective Catalytic Reduction).

  The exhaust gas passes through the post-processing device 11 and is then discharged into the atmosphere via a muffler (not shown).

  The holding part 12 is a cylindrical metal member, for example. The holding part 12 is provided in the exhaust gas passage 10 so that the outer peripheral surface thereof is in contact with the inner peripheral surface of the exhaust gas passage 10.

  The post-processing device 11 is held in the hollow portion H of the holding unit 12. At this time, the post-processing device 11 is disposed in the hollow portion H so that the outer peripheral surface thereof is in contact with the inner peripheral surface of the holding unit 12.

  A vacuum sealed chamber R is formed between the outer peripheral surface and the inner peripheral surface of the holding unit 12. In this sealed chamber R, a heat retaining member 13 having a heat retaining function is accommodated.

  The heat retaining member 13 is, for example, a fibrous mat formed of ceramic fibers. Ceramic beads having a vacuum inside may be mixed in the ceramic fibers.

  In addition, since heat retention improves, so that the contact part of the inner peripheral surface of the holding | maintenance part 12 and the outer peripheral surface of the post-processing apparatus 11 is large, the length of the longitudinal direction (exhaust gas flow direction) of the holding | maintenance part 12 is the back. It is desirable that it is equal to or longer than the length of the processing device 11 in the longitudinal direction.

  As described above, according to the exhaust structure of the present embodiment, the vacuum sealed chamber R is formed in the holding portion 12 provided in contact with the post-processing device 11, and the heat retaining member 13 is provided in the sealed chamber R. Therefore, the heat retention of the post-processing device 11 can be further improved. As a result, the number of executions and the execution time of the temperature increase control can be reduced, and fuel efficiency is improved.

  Further, according to the exhaust structure of the present embodiment, since the heat retaining member 13 is accommodated in the sealed chamber R, the holding portion 12 can be prevented from being crushed when the sealed chamber R is brought into a vacuum state. .

  It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the spirit of the present invention.

  For example, in the above embodiment, the case where one post-processing device 11 is held by one holding unit 12 has been described as an example, but the present invention is not limited to this. One post-processing device 11 may be held by a plurality of holding units. This specific example will be described below with reference to FIG.

  In the example of FIG. 2, the post-processing device 11 is held by three holding units 12a, 12b, and 12c. The holding parts 12 a to 12 c are adjacent to each other along the longitudinal direction of the post-processing device 11. The length in the longitudinal direction of each of the holding units 12a to 12c is the same length (for example, 1/3 of the length in the longitudinal direction of the post-processing device 11).

  Each of the holding units 12a to 12c has the same configuration as the holding unit 12 illustrated in FIG.

  That is, the holding portions 12 a to 12 c are, for example, cylindrical metal members, and the outer peripheral surfaces of the holding portions 12 a to 12 c are in contact with the outer peripheral surface of the exhaust gas passage 10.

  The post-processing device 11 is held in each hollow portion H of the holding portions 12a to 12c. At this time, the outer peripheral surface of the post-processing device 11 is in contact with the inner peripheral surfaces of the holding portions 12a to 12c.

  In each of the holding portions 12a to 12c, a vacuum sealed chamber R is formed between the outer peripheral surface and the inner peripheral surface, and the heat retaining members 13a to 13c are accommodated in each sealed chamber R.

  In addition, since heat retention improves, so that the contact part of each inner peripheral surface of holding | maintenance part 12a-12c and the outer peripheral surface of post-processing apparatus 11 is large, in the longitudinal direction (direction which waste gas flows) of holding | maintenance part 12a-12c. The total length is preferably equal to or longer than the length of the post-processing device 11 in the longitudinal direction.

  As described above, the exhaust structure of the present modification can obtain the same effects as the embodiment. Moreover, by preparing a plurality of holding portions having a length in the longitudinal direction shorter than the length in the longitudinal direction of the post-processing device 11 and the same length as the holding portions 12a to 12c of the present modification example. , It can correspond to various longitudinal length post-processing devices. That is, since it is not necessary to produce the holding portion according to the length in the longitudinal direction of the post-processing apparatus, the cost can be reduced.

<Summary of this disclosure>
The exhaust structure of the present invention is an exhaust structure that includes an exhaust gas channel that guides exhaust gas of an internal combustion engine into the atmosphere, and an aftertreatment device that is disposed in the exhaust gas channel, and holds the aftertreatment device. It has a cylindrical holding part, the inner peripheral surface of the holding part is in contact with the outer peripheral surface of the post-processing apparatus, and between the outer peripheral surface of the holding part and the inner peripheral surface of the holding part, A vacuum sealed chamber is formed, and the sealed chamber is provided with a heat retaining member having a heat retaining function.

  In the exhaust structure, an outer peripheral surface of the holding portion may be in contact with an inner peripheral surface of the exhaust gas flow path.

  Moreover, the said exhaust structure WHEREIN: The said holding | maintenance part may be provided with two or more along the longitudinal direction of the said post-processing apparatus.

  In the exhaust structure, the heat retaining member may be a fibrous mat formed of ceramic fibers, and ceramic beads having a vacuum inside may be mixed in the ceramic fibers.

  In the exhaust structure, the aftertreatment device may be any one of an oxidation catalyst, DPF, GPF, or urea SCR.

  The present invention can be applied to an exhaust structure that exhausts exhaust gas generated in an internal combustion engine.

DESCRIPTION OF SYMBOLS 10 Exhaust gas flow path 11 Aftertreatment apparatus 12, 12a, 12b, 12c Holding | maintenance part 13, 13a, 13b, 13c Thermal insulation member

Claims (5)

An exhaust structure comprising an exhaust gas passage for guiding exhaust gas of an internal combustion engine into the atmosphere, and an aftertreatment device disposed in the exhaust gas passage,
A cylindrical holding part for holding the post-processing device;
The inner peripheral surface of the holding part is in contact with the outer peripheral surface of the post-processing device,
A vacuum sealed chamber is formed between the outer peripheral surface of the holding portion and the inner peripheral surface of the holding portion,
The sealed chamber is provided with a heat retaining member having a heat retaining function,
Exhaust structure. The outer peripheral surface of the holding part is in contact with the inner peripheral surface of the exhaust gas flow path,
The exhaust structure according to claim 1. The holding part is
A plurality of the post-processing devices are provided along the longitudinal direction of the post-processing device.
The exhaust structure according to claim 1 or 2. The heat retaining member is a fibrous mat formed of ceramic fibers,
The ceramic fibers are mixed with ceramic beads whose inside is vacuum,
The exhaust structure according to any one of claims 1 to 3. The post-treatment device is one of an oxidation catalyst, DPF, GPF, or urea SCR.
The exhaust structure according to any one of claims 1 to 4.

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