JPH0596426U - Metal carrier for exhaust gas purification - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] The present invention provides an exhaust gas purifying metal carrier capable of preventing the honeycomb body from popping out even when a part of the metal honeycomb body is melted at the time of a misfire of an automobile engine. [Structure] In a metal carrier constituted by inserting a flat foil and a corrugated foil made of metal into a spiral shape and inserting the honeycomb body into a metal outer cylinder, the flat foil and the corrugated foil are joined at an end portion on an exhaust gas inlet side. In addition, 1 cross-section bonding is performed inside the honeycomb body that is away from the end in the axial direction of the carrier, and the bonding in the vicinity of the outer circumference is from the outermost circumference 1 round or more to the outermost layer 1/3 or less of the maximum total number of turns. Metal carrier for exhaust gas purification, characterized in that it is joined over its entire length in the direction

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an exhaust gas purifying metal carrier used for purifying exhaust gas emitted from an automobile engine or the like.

[0002]

[Prior Art]

 As a catalyst carrier for purifying exhaust gas, a catalyst carrier in which a honeycomb body is formed by using a heat-resistant metal foil has been developed and has already been partially put into 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, the flat foil and the corrugated foil forming the honeycomb body as disclosed in Japanese Patent Application No. 110610/1989 are joined at least at one end of the honeycomb body. In addition, regarding the bonding in the vicinity of the outer periphery of the honeycomb body, the structure in which the entire length is partially bonded in the axial direction from the outermost periphery to reduce the thermal stress is the best. However, in this structure where the exhaust gas inlet end is joined, the gas at engine misfire burns just below the honeycomb end face joint, and when the melting point of the foil is exceeded, melting loss occurs and the foil on the outlet side of the melted portion Since it is separated from the end face joint of the honeycomb, the flat foil and the corrugated foil in the honeycomb body may pop out and scatter. As described above, the countermeasure against misfire is insufficient, and in the above-mentioned type, a part of the honeycomb body on the exhaust gas emission side is scattered to reduce the purifying ability of the catalyst or the efficiency of the engine.

[0003]

[Problems to be solved by the device]

 In view of the current situation, the present invention is for exhaust gas purification that does not cause problems such as popping out and scattering of the honeycomb body even if a part of the metal honeycomb body is melted by being exposed to high temperature due to combustion in the honeycomb body when an automobile engine misfires. A metal carrier is provided.

[0004]

[Means for Solving the Problems]

 The exhaust gas purifying metal carrier of the present invention has the following structure. (1) A metal carrier in which a flat foil and a corrugated foil made of a heat-resistant metal are superposed and wound in a spiral shape, and a metal outer cylinder surrounding the outer peripheral surface thereof is joined, wherein the flat foil of the honeycomb body The corrugated foil and the corrugated foil are joined at the end on the exhaust gas inlet side, and one cross-section is joined inside the honeycomb body that is distant from the end in the axial direction of the carrier. The layers must be joined over the entire length in the axial direction from the layer to less than one-third of the maximum number of turns. (2) The honeycomb body and the outer cylinder described in the preceding paragraph are joined so that the axial joining ranges of the honeycomb body and the outer cylinder do not overlap with the end joining region on the honeycomb body discharge gas inlet side. (3) In the metal carrier according to the preceding 2 items, the bonding performed inside the honeycomb body is located at a position apart from the carrier upper end surface by a quarter or more of the carrier axial length. The present invention will be described in detail below. According to the present invention, in order to solve the above-mentioned problems, the flat foil and the corrugated foil of the honeycomb body are joined at the end portion on the exhaust gas inlet side and inside the honeycomb body away from the end portion in the axial direction of the carrier. The cross-section bonding prevents the honeycomb body from popping out and scattering. Further, in addition to the above, in the vicinity of the outer peripheral portion of the honeycomb body, the entire length in the axial direction from the outermost peripheral layer or more to the outermost layer or less and one third or less of the maximum total number of windings should be bonded. The honeycomb body is bonded so that it does not overlap with the end joint area on the exhaust gas inlet side, so that the displacement of the honeycomb body due to foil breakage due to thermal stress is also prevented.

As described above, the present invention was developed by focusing on the position of melting damage in the honeycomb body due to engine misfire. That is, since melting loss in the honeycomb body occurs immediately below the gas inlet side end face of the honeycomb body, even if the melted portion of the honeycomb body is melted down, in order to prevent the melted lower honeycomb body from popping out, It is effective to bond inside the honeycomb below. Further, it is desirable that the joining position is close to the melted portion. When bonded to the exit side end of the honeycomb body, vibration occurs when the melted part is separated from the upper honeycomb body, and the exit side bonded part is easily damaged. However, if the joining position is too close to the end joining part on the exhaust gas inlet side, there is a risk that the joining will melt. Therefore, the joining position should be separated from the upper end face of the carrier by a quarter or more of the carrier axial length. Set it appropriately depending on the position.

Next, an embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is a schematic cross-sectional view of the present invention, wherein 1 is a metal honeycomb body formed by stacking flat foils and corrugated foils made of heat-resistant metal and spirally winding them, and 2 is a metal honeycomb. It is a metal outer cylinder that surrounds the side surface (outer peripheral surface) of the body 1. The metal carrier of the present invention is constructed 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 portion 3 on the exhaust gas inlet side, and the outer peripheral joint portion 4 is provided in a range of one or more turns from the outermost circumference and one third or less of the total number of turns. The flat foil and the corrugated foil are joined at the outer peripheral joint portion 4, and the transverse joint portion 5 is provided on the honeycomb body 1. Melting loss occurs immediately below the end face on the exhaust gas inlet side due to engine misfire. Therefore, when the end portion 3 on the exhaust gas inlet side melts away, the melt-dissipated lower honeycomb body disappears from the honeycomb body 1 because there is no joint. Even if the end portion 3 on the exhaust gas inlet side is melted down, the transverse joining portion 5 joins the portion located under the melted portion, so that the protrusion of the melted lower honeycomb body is eliminated. Reference numeral 6 in the drawing denotes a joint portion 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 that form the honeycomb body 1, it is possible to prevent the honeycomb body from popping 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 inlet side and the corrugated foil are joined do not overlap. The reason is that when the outer cylinder and the honeycomb body are bonded together, thermal stress occurs between them. In particular, since the temperature at the joint at the inlet end is the highest, expansion and contraction inside the honeycomb body causes the heat applied to that portion if the outer cylinder and the honeycomb body are joined at that portion. Respond becomes the largest. Therefore, the joint between the outer cylinder and the honeycomb body is designed not to overlap the inlet end.

FIG. 2 shows an example in which the transverse joint portion 5 in the honeycomb body 1 is located at a position apart from the upper end surface of the honeycomb body by 3/4 of the carrier axial length. Such a honeycomb body 1 is advantageous as a measure against misfire when the carrier length is short.

[0010]

[Effect of the device]

 According to the metal carrier of the present invention, it was possible to prevent the honeycomb body from being displaced or popping out. As a result, the honeycomb body is prevented from popping out and scattering due to melting damage at the time of misfire, and it is possible to prevent deterioration of the catalyst purification capacity.

[Brief description of drawings]

FIG. 1 is an explanatory view schematically showing a cross section of a 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 inlet side end of honeycomb body 4 Outer peripheral connection portion of honeycomb body 5 Cross-joint portion

Claims (3)

[Scope of utility model registration request] 1. A metal carrier in which a flat foil and a corrugated foil made of a heat-resistant metal are superposed and spirally wound, and a metal outer cylinder surrounding an outer peripheral surface of the metal honeycomb body is joined, wherein the honeycomb body is formed. The flat foil and the corrugated foil to be formed are joined at the end on the exhaust gas inlet side, and one transverse cross-section is joined inside the honeycomb body distant from the end in the axial direction of the carrier, and the joining near the outer peripheral portion is the outermost periphery. Maximum number of windings is 3 from the outermost layer for one lap or more
An exhaust gas purifying metal carrier, characterized in that it is joined to the whole length in the axial direction up to 1/10 or less. 2. The honeycomb structure according to claim 1, wherein the honeycomb body and the outer cylinder are joined together so that the axial joining ranges of the honeycomb body and the outer cylinder do not overlap with the end joining region on the exhaust gas inlet side of the honeycomb body. Metal carrier for exhaust gas purification. 3. The exhaust gas purifying metal according to claim 1, wherein, in the joining performed inside the honeycomb body, the joining position is separated from the upper end surface of the carrier by a quarter or more of the axial length of the carrier. Carrier.