JP2543636Y2 - Metal carrier for exhaust gas purification - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying metal carrier used for purifying exhaust gas discharged from an automobile engine or the like.

[0002]

2. Description of the Related Art As a catalyst carrier for purifying exhaust gas, a catalyst carrier formed of a honeycomb body using heat-resistant metal foil has been developed.
Some are already in practical use. These metal carriers have been required to have heat resistance and oxidation resistance to withstand high-temperature exhaust gas and structural reliability to withstand thermal fatigue and thermal stress. When severe thermal stress is applied, bonding of a flat foil and a corrugated foil constituting a honeycomb body as disclosed in Japanese Patent Application No. 1-110610,
Regarding the joining in the vicinity of the outer peripheral portion of the honeycomb body, at least one of both ends of the honeycomb body, and a structure in which the entire outer peripheral portion is partially joined in the axial direction to reduce the thermal stress is most excellent. However, in the structure of joining at the exhaust gas inlet end, the gas at the time of engine misfire burns immediately below the honeycomb end face joint, and when the melting point of the foil is exceeded, melting occurs and the foil at the eroded part exit side becomes honeycomb. Because it is separated from the end face joint,
The flat foil and corrugated foil in the honeycomb body may fly out and scatter. As described above, countermeasures against misfire are insufficient. In the above-mentioned type, a part of the honeycomb body on the exhaust gas outlet side is scattered to lower the catalyst purifying ability or the engine efficiency.

[0003]

SUMMARY OF THE INVENTION In view of the above situation, the present invention is based on such a situation that when a vehicle engine is misfired, combustion occurs in the honeycomb body and is exposed to a high temperature, and a part of the honeycomb body is melted and damaged.
An object of the present invention is to provide a metal carrier for purifying exhaust gas in which a honeycomb body does not cause any trouble such as jumping out and scattering.

[0004]

The gist of the present invention is as follows. (1) In a metal carrier obtained by joining a metal honeycomb body formed by superimposing a flat foil and a corrugated foil made of a heat-resistant metal and spirally winding and a metal outer cylinder surrounding the outer peripheral surface thereof, the flat foil of the honeycomb body is used. and bonding the corrugated sheet, together with the made at the end of the exhaust gas inlet side, combined 1 transverse interview honeycomb body interior spaced support axis from the end portion, the junction of the outer peripheral portion near the outermost one turn or more, the outer periphery It shall be joined along the entire length in the axial direction from the layers to a maximum of one third of the total number of turns. (2) The honeycomb body and the outer cylinder are joined so that the axial joining range of both the honeycomb body and the outer cylinder does not overlap with the end joining region on the exhaust gas entry side of the honeycomb body. (3) In the metal carrier of the preceding two paragraphs, the joining performed inside the honeycomb body is performed on the exhaust gas inlet side at least one quarter of the carrier shaft length.
It is characterized in that it is located at a position away from the upper end surface of the end. Hereinafter, the present invention will be described in detail. According to the present invention, in order to solve the above-described problem, the flat foil and the corrugated foil of the honeycomb body are joined at the end on the exhaust gas entry side, and the inside of the honeycomb body is separated from the end in the axial direction of the carrier. The joining of the cross sections prevents the honeycomb body from jumping out and scattering. Further, in addition to the above, the bonding in the vicinity of the outer peripheral portion of the honeycomb body is performed at least one-third of the total number of turns from the outermost peripheral layer or more.
Joining the entire length in the axial direction to the following, and joining the honeycomb body and outer cylinder so that they do not overlap with the end joining area on the honeycomb body exhaust gas entry side, displacement of the honeycomb body due to foil fracture due to thermal stress Is also prevented.

As described above, the present invention has been developed by focusing on the erosion position in the honeycomb body due to engine misfire. That is, since the erosion in the honeycomb body occurs just below the end face of the honeycomb body on the gas entry side, even if that part is eroded, in order to prevent the erosion lower honeycomb body from popping out, the lower part of the erosion part is required. It is effective to join inside the honeycomb. It is desirable that the joining position is close to the erosion part. When joined to the honeycomb body exit side end, when the eroded portion is separated from the upper honeycomb body, vibration occurs, and the exit side joint is easily damaged. However, if the joining position is too close to the end joining portion on the exhaust gas entrance side, there is a risk that the joining will be melted and damaged. Therefore, the joining position is at least one-quarter of the length of the carrier shaft . Set appropriately at a position away from the upper end surface.

Next, an embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 schematically shows a cross section of the present invention, 1 is a metal honeycomb body formed by superimposing a flat foil and a corrugated foil made of a heat-resistant metal and spirally winding them.
Reference numeral 2 denotes a metal outer cylinder surrounding the side surface (outer peripheral surface) of the metal honeycomb body 1. The metal carrier of the present invention is configured by joining the honeycomb body 1 and the outer cylinder 2, and the feature of the present invention is to specify the joining position of the flat foil and the corrugated foil of the honeycomb body 1.
That is, the flat foil and the corrugated foil are joined (hatched portion) at the end 3 on the exhaust gas entry side, and the total number of turns is 3 or more from the outermost circumference.
The outer peripheral joint 4 is provided in a range of one-tenth or less, the flat foil and the corrugated foil are joined at the outer peripheral joint 4, and the transverse joint 5 is provided on such a honeycomb body 1. Due to engine misfire, erosion occurs immediately below the exhaust gas entry side end face. Therefore, if the end 3 on the exhaust gas entry side is eroded, the eroded lower honeycomb body has no joining portion and jumps out of the honeycomb body 1. Even if the end portion 3 on the exhaust gas entry side is melted, the transverse joint portion 5 joins a portion located below the eroded portion, so that the protrusion of the eroded lower honeycomb body is eliminated. In the figure, reference numeral 6 denotes a joint between the honeycomb body 1 and the outer cylinder 2.

As described above, by specifying the joining position of the flat foil and the corrugated foil constituting the honeycomb body 1, it is possible to prevent the honeycomb body from jumping out and scattering.

Further, it is preferable that the joining portion 6 between the honeycomb body 1 and the outer cylinder 2 and the end portion 3 where the flat foil on the exhaust gas entry side and the corrugated foil are joined so as not to overlap. The reason is that when the outer cylinder and the honeycomb body are joined, thermal stress is generated therebetween. In particular, since the temperature is the highest at the joining portion at the entry side end, if the outer cylinder and the honeycomb body are joined at that portion due to expansion and contraction inside the honeycomb body, the thermal stress applied to that portion will be reduced. The largest. Therefore, the joining between the outer cylinder and the honeycomb body is made not to overlap with the entry-side end.

FIG. 2 shows an example in which the transverse joint 5 in the honeycomb body 1 is located at a distance of three quarters of the length of the carrier shaft from the upper end surface of the honeycomb body. Such a honeycomb body 1 is advantageous as a measure against misfire when the carrier length is short.

[0010]

[Effects of the Invention] According to the metal carrier of the present invention, it was possible to prevent the honeycomb body from shifting and popping out. As a result, the honeycomb body is prevented from jumping out and scattering due to the melting loss at the time of misfire, so that a reduction in the catalyst purification ability can be prevented.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a cross section of the metal carrier of the present invention.

FIG. 2 is an explanatory view schematically showing a cross section of another metal carrier of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Honeycomb body 2 Outer cylinder 3 Exhaust gas entry side end of honeycomb body 4 Outer peripheral connection part of honeycomb body 5 Transverse joint

Claims (3)

(57) [Scope of request for utility model registration] 1. A metal carrier obtained by joining a metal honeycomb body formed by superimposing a flat foil and a corrugated foil made of a heat-resistant metal and spirally winding the same to a metal outer cylinder surrounding the outer peripheral surface thereof. The joining of the flat foil and the corrugated foil is performed at the end on the exhaust gas entry side, and one cross section is joined inside the honeycomb body away from the end in the carrier axial direction, and the joining near the outer periphery is the outermost periphery A metal carrier for purifying exhaust gas, wherein the metal carrier is joined over the entire length in the axial direction from at least one turn to at most one third of the total number of turns from the outer peripheral layer. 2. The honeycomb structure according to claim 1, wherein both the honeycomb body and the outer cylinder are joined so that an axial joining range of the honeycomb body and the outer cylinder does not overlap with an end joining area on an exhaust gas inlet side of the honeycomb body. Exhaust gas purification metal carrier. 3. A junction place inside the honeycomb body, one or more gas inlet a quarter of a carrier shaft length thereof joining position
The exhaust gas purifying metal carrier according to claim 1, wherein the metal carrier is separated from an upper end surface of a side end portion .