JP3667811B2 - Metal carrier - Google Patents

Description

【００３４】
以上のように、本発明の各種メタル担体および比較の従来の各種メタル担体は何れも、耐久試験に合格したが、従来のメタル担体Ｆは中間体の変形自由度が不足し相対的に耐久度が低い。またメタル担体Ｅは良好な耐久性を示したが、製造プロセスが複雑なため、製造コストが高くなる短所がある。
それに比べ本発明のメタル担体Ａ，Ｃ，Ｄは、耐久性および製造コストのバランスがとれ、従来のメタル担体より総合的に優秀である。
【００３５】
【発明の効果】
以上説明したように、本発明によれば、メタル担体の構造を合理化することにより、低コストで耐久性の優れたメタル担体を供給できることが判明した。
【図面の簡単な説明】
【図１】 本発明のメタル担体の外観を示す斜視図。
【図２】 本発明のメタル担体の各構成要素の一例を示す外観斜視図。
【図３】 本発明の実施例（メタル担体Ａ）を示す断面図。
【図４】 本発明の実施例（メタル担体Ｃ）を示す断面図。
【図５】 本発明の実施例（メタル担体Ｄ）を示す断面図。
【図６】 本発明の実施例を示すメタル担体の横断面図。
【図７】 本発明の実施例を示すメタル担体の横断面図。
【図８】 本発明の実施例を示すメタル担体の横断面図。
【図９】 本発明の実施例を示すメタル担体の横断面図。
【図１０】 本発明のメタル担体と比較するための公知のメタル担体Ｅの縦断面図。
【図１１】 本発明のメタル担体と比較するための公知のメタル担体Ｆの縦断面図。
【図１２】 各種メタル担体の耐久性を評価するための熱サイクルパターンを示す図。
【符号の説明】
１ メタル担体
２ 平箔
３ 波箔
４ ハニカム体
５ 中間体
６ 外筒
７ ハニカム体と中間体との接合部
８ 中間体と外筒の接合部
９ 中間体の非接合部
１０ 接合部位をパターン化したハニカム体
１１ ハニカム体と外筒の接合部
１２ 中間体
１３ ハニカム体と中間体の接合部
１４ 中間体と外筒の接合部[0001]
[Industrial application fields]
The present invention relates to a metal carrier for purifying exhaust gas discharged from an internal combustion engine such as an automobile engine.
[0002]
[Prior art]
Conventionally, a ceramic metal carrier has been used in a catalytic converter for purifying exhaust gas, but recently, the use of a metal carrier has been increased from the viewpoint of heat resistance, low pressure loss and mountability.
[0003]
A metal carrier is formed by winding a flat foil made of a metal such as ferritic stainless steel having a heat resistance of about 50 μm in thickness and a corrugated corrugated foil to form a honeycomb body. Similarly, they are housed in an outer tube made of corrosion-resistant and heat-resistant metal such as ferritic stainless steel having heat resistance, and are joined to each other by brazing or the like.
[0004]
This metal carrier is loaded and used, for example, in an exhaust system of an automobile engine after a catalyst for purifying exhaust gas such as platinum, palladium, rhodium, etc. is supported.
For this reason, the metal carrier is subjected to severe temperature changes and vibrations accompanying changes in operating conditions, but if it is damaged, not only the purification performance deteriorates but also the exhaust system is closed or the engine is damaged, so that particularly high durability is required.
[0005]
The thermal stress acting on the metal carrier is particularly large between the outer cylinder and the honeycomb body having a large temperature difference, and various joining structures have been proposed in order to alleviate the stress.
For example, as shown in Japanese Patent Laid-Open No. 4-148016, the joint structure inside the honeycomb body and the joint portion between the honeycomb body and the outer cylinder are specified, the degree of freedom with respect to thermal deformation is increased, and a so-called flexible structure is formed. A lowering method, or as disclosed in JP-A-3-157139 and JP-A-2-298620, a cylindrical intermediate body is disposed between the honeycomb body and the outer cylinder, and the honeycomb body and the outside However, there is a method of increasing the degree of freedom with respect to thermal deformation by not joining the two joints in the axial direction.
[0006]
The conventional method streamlines the joint structure between the honeycomb body and between the outer cylinder and the honeycomb body, or by providing an intermediate body, thereby increasing the degree of freedom against thermal deformation and ensuring good durability. There is a problem that the manufacturing is complicated, the productivity is low, and the cost is high. When the honeycomb body is diffusion-bonded, all the contact points between the flat foil and the corrugated foil are bonded unless special measures are taken. However, when the honeycomb body is bonded as a whole, the outer cylinder and the honeycomb body are bonded together. Although it is necessary to further increase the degree of freedom with respect to the deformation in the meantime, the conventional method is insufficient, and there has been a problem that the honeycomb body supporting portion is broken and shifted at the end.
[0007]
[Problems to be solved by the invention]
In the present invention, the entire honeycomb body of the metal carrier is joined or the temperature change of the exhaust gas is large, and in the conventional method, the degree of freedom in deformation between the honeycomb body and the outer cylinder is insufficient, so high durability cannot be obtained. In this case, a metal carrier provided with a high degree of freedom by a simple method by providing an intermediate between the outer cylinder and the honeycomb body is provided.
[0008]
[Means for Solving the Problems]
That is, the present invention is a durable metal carrier,
(1) After forming a honeycomb body in which flat foil and corrugated foil are alternately wound or laminated, an intermediate body is formed by winding a thin plate that is the same as or thicker than the foil twice or more on the outside. The inner surface of the body and the outer surface of the honeycomb body are continuously joined in a full length in the axial direction, and the outer surface of the intermediate body is joined in a full length in the axial direction with the outer cylinder within one turn. A metal carrier characterized by providing a bonding layer;
(2) The metal carrier as set forth in (1) above, wherein the inside of the honeycomb body is entirely joined, (3) Before (1) or (), wherein the intermediate body is a flat plate not corrugated. 2) the metal carrier according to
(4) The metal carrier according to (1) or (2) above , wherein the corrugated intermediate plate is used as the intermediate.
[0009]
The present invention will be described in detail below.
FIG. 1 is an external view of a metal carrier 1 of the present invention. An intermediate body 5 wound twice or more is disposed outside the honeycomb body 4 formed by winding or laminating the flat foil 2 and the corrugated foil 3, and an outer cylinder 6 is disposed outside the intermediate body 5. In the same configuration, the honeycomb body 4 is bonded to the inner surface of the intermediate body 5, and the outer surface of the intermediate body 5 is bonded to the inner surface of the outer cylinder 6. However, the inside of the intermediate body 5 wound in multiple is not joined.
[0010]
The plate thickness of the intermediate body 5 is set to be thinner than the outer cylinder 6 and thicker than the flat foil 2 and the corrugated foil 3 constituting the honeycomb body.
The intermediate body 5 is joined to the honeycomb body 4 continuously or intermittently for one round, and the outer body 6 is joined to the outer cylinder 6 continuously or intermittently within one round.
[0011]
Therefore, the intermediate body 5 of the metal carrier 1 of the present invention has a role like a coil spring that holds the honeycomb body 4 on the inner periphery and is coupled to the outer cylinder 6 on the outer surface in terms of thermal stress, and has a radius The non-bonding layer in the intermediate body 5 acts as a heat insulating layer, and the temperature difference between the honeycomb body 4 and the intermediate body 5 is reduced, and at the same time, the intermediate body The temperature difference between 5 and the outer cylinder 6 is also reduced, and the stress generated between the honeycomb body 4 and the outer cylinder 6 can be reduced.
[0012]
Since the honeycomb body 4 is coated with a catalyst, the reaction heat is generated and a thermal stress is generated in the axial direction. However, since the honeycomb bodies 4 are entirely joined, the displacement in the axial direction is forcibly restrained, so that the amount of displacement is reduced and good durability can be ensured.
[0013]
FIG. 2 is a diagram showing the configuration of the metal carrier 1 of the present invention. FIG. 2A shows the appearance of a honeycomb body 4 formed by winding a flat foil 2 and a corrugated foil 3, and FIG. 2B shows the appearance of an intermediate body 5 that wraps and wraps the honeycomb body 4. Has been curled more than once. In FIG. 2, the intermediate is shown as a flat thin plate, but the corrugated corrugated foil may be curled twice or more in the same manner. (C) The figure shows the external appearance of the outer cylinder 6 that houses the honeycomb body 4 and the intermediate cylinder 5. These contact surfaces are, for example, a brazing material for bonding to each other in the case of brazing, or in the case of diffusion bonding, the interface bonding is cleaned and prepared to be bonded, and on the contrary, a bonding inhibitor is used for a portion that is not bonded. Etc. are applied, and a necessary pressurizing force is applied and assembled so as to adhere.
[0014]
Hereinafter, various joining structures in the metal carrier of the present invention are shown.
FIGS. 3 to 5 show an example of the joining structure in the vertical cross section of the metal carrier, and FIGS. 6 to 9 show the joining structure of the cross section of each metal carrier. In addition, the joining structure of these vertical cross sections and the joining structure of a cross section do not have a specific combination, and can be used combining them suitably.
[0015]
In FIG. 3, the honeycomb body 4 has an area indicated by hatching in which all contact points of the flat foil and the corrugated foil are bonded in principle by, for example, diffusion bonding or brazing. Reference numeral 5 denotes an intermediate body, but a portion 7 (a portion in a range indicated by a dot) that is in contact with the outer surface of the honeycomb body 4 on the inner surface is joined to the entire length in the axial direction. Similarly, a portion 8 (a portion in a range indicated by a dot) in contact with the outer surface of the intermediate body 5 and the inner surface of the outer cylinder 6 is joined to the entire length in the axial direction. However, the intermediate layer 9 other than the inner and outer surfaces of the intermediate body 5 is not joined.
[0016]
FIG. 4 is employed when, for example, the joint between the honeycomb body 4 and the outer cylinder 6 of the intermediate body 5 is protected from high-temperature exhaust gas. The honeycomb body 4 has a range indicated by hatching, for example, diffusion bonding or brazing. As a result, all the contacts of the flat foil and the corrugated foil are joined in principle. A portion 7 in contact with the outer surface of the honeycomb body 4 on the inner surface of the intermediate body 5 is joined in the axial direction, for example, a specific range on the outlet side of the exhaust gas, and a portion 8 in contact with the inner surface of the outer cylinder 6 is in the axial direction, for example, the exhaust gas. The specific area on the exit side is joined. However, the intermediate layer 9 other than the inner and outer surfaces of the intermediate body 5 is not joined. In addition, although the length of the intermediate body 5 is stopped in the joining range in FIG. 4 , it does not interfere even if it is longer than the joining length.
[0017]
FIG. 5 is employed when, for example, the honeycomb body 5 is short in length, so that it is prevented from tilting in the outer cylinder 6 during use. Although the length of the honeycomb body 4 is short in the figure, the intermediate body 5 and the outer cylinder 6 are longer than the honeycomb body 4 and have a length that can maintain the posture even when deformation occurs during use. . In the honeycomb body 4, all the contact points of the flat foil and the corrugated foil are bonded in principle by the diffusion bonding or brazing, for example, in the range indicated by the oblique lines as described above. A portion 7 in contact with the outer surface of the honeycomb body 4 on the inner surface of the intermediate body 5 is joined in the axial direction, for example, full length, and a portion 8 in contact with the inner surface of the outer cylinder 6 is joined in the axial direction, for example, in the full length. However, the intermediate layers 9 other than the inner and outer surfaces of the intermediate body 5 are not joined.
[0018]
In FIG. 6 , the contact points of the flat foil and the corrugated foil in the range indicated by diagonal lines are all bonded to the honeycomb body 4, and the inner surface of the intermediate body 5 is bonded to the entire circumference (the part indicated by the points). The outer surface of 5 is joined to the outer cylinder 6 on the entire circumference (parts in a range indicated by dots). However, the intermediate layer 9 of the intermediate body 5 is not joined.
[0019]
In FIG. 7 , the intermediate body 5 and the outer cylinder 6 have a joining structure that is employed when it is not necessary to join the entire circumference since the intermediate body 5 and the outer cylinder 6 are thicker than the foil of the honeycomb body 4. The bonding inside the honeycomb body 4 and the bonding between the honeycomb body 4 and the intermediate body 5 are the same as in the case of FIG. 6 , but the outer surface of the intermediate body 5 and the inner surface of the outer cylinder 6 are not the entire circumference, but are limited to a part. The region in the range not indicated by the point is not joined. In this case, if the non-joined portion of the intermediate body 5 is not required one or more rounds, the intermediate body 5 can be saved by setting the curling range of the intermediate body 5 as two or less rounds as an application of the present invention.
[0020]
FIG. 8 shows a structure that is adopted when saving the bonding material between the intermediate body 5 and the outer cylinder 6. That is, the parts in the range indicated by the points between the intermediate body 5 and the outer cylinder 6 are joined, and the parts not joined in the range not indicated by the points are alternately arranged. It is the same as the above that the layers inside the intermediate body 5 are not joined.
[0021]
FIG. 9 shows a structure that is employed when the bonding material between the honeycomb body 4 and the intermediate body 5 and between the intermediate body 5 and the outer cylinder 6 is saved. Parts in the range indicated by dots in the figure are joined, and parts in a range not shown are not joined. That is, the honeycomb body 4 is joined as a whole, the honeycomb body 4 and the intermediate body 5 are joined intermittently, and the intermediate body 5 is joined with a part of the outer cylinder 6.
[0022]
As the above-mentioned application, it is possible to further improve the durability by adopting a known honeycomb body provided with a non-joined portion at a specific location inside the metal carrier of the present invention. However, from the manufacturing cost, it is more advantageous to adopt a honeycomb body bonded as a whole as in the present invention.
[0023]
The metal carrier 1 of the present invention is used, for example, after being loaded with a noble metal such as platinum, palladium or rhodium for purifying exhaust gas, for example, in the exhaust system of an automobile, in the same manner as a conventionally known metal carrier. At the same location, the metal carrier is subjected to a drastic temperature change, so that a large temperature difference occurs in the radial direction, and a strong compressive tensile force acts on the honeycomb body 4 in the outer cylinder 6.
[0024]
The honeycomb body 4 is pressed against the outer cylinder 6 via the intermediate body 5 due to thermal expansion. However, due to the first thermal expansion, the outer layer of the honeycomb body 4 is slightly crushed and the outer diameter is reduced. Compressive stress almost does not work. On the other hand, the tensile force due to thermal contraction is generated by repeating thermal expansion and thermal contraction every thermal cycle. However, since the intermediate body 5 in which the inner layers are not bonded is provided, the deformation is absorbed and the stress generated in the honeycomb body 4 is greatly reduced. Furthermore, since the non-bonding layer of the intermediate body 5 is thermally insulated from the outer cylinder, the temperature distribution generated in the honeycomb body is improved and the durability is improved.
Next, examples of the present invention will be described.
[0025]
【Example】
FIG. 3 shows a metal carrier A according to an embodiment of the present invention. FIG. 6 shows a cross-sectional joining structure. The outer cylinder 6 is ferritic stainless steel having 19Cr-0.4Nb as an alloy component, and has an outer diameter of 100 mm, a length of 110 mm, and a thickness of 1.5 mm. The honeycomb body 4 is a ferritic stainless steel having 20Cr-5A as an alloy component, and has an outer diameter of 96.4 and is composed of a flat foil 4 and a corrugated foil 5 having a thickness of 50 μm. The cell density of the honeycomb body 4 is 400 cells / square inch. The intermediate body 5 is a philitic stainless steel containing 20Cr-5Al as an alloy component, and its length is 100 mm, it is curled twice, its outer diameter is 97 mm, and its thickness is 150 μm.
[0026]
Also, the inside of the honeycomb body 4 is joined by brazing or diffusion joining, and the joining of the honeycomb body 4 and the intermediate body 5 and the joining of the intermediate body 5 and the outer cylinder 6 are joined by a Ni brazing material containing Ni as a main component. Yes.
[0027]
FIG. 4 shows a metal carrier C according to another embodiment of the present invention. The junction structure of the cross-section shown in FIG. Except for the outer cylinder 6 and the length of 50 mm, the intermediate body 5 is also the same as the metal carrier A in the material, dimensions and joining method of the honeycomb body 4. The intermediate body 5 is disposed on the outlet side from the center of the metal carrier, the honeycomb body 4 and the intermediate body 5 are full length in the axial direction, and the intermediate body 5 and the outer cylinder 6 are brazed in the full length in the axial direction.
[0028]
FIG. 5 shows a metal carrier D according to another embodiment of the present invention. The junction structure of the cross-section shown in FIG. The material, dimensions, and joining method are the same as those of the metal carrier A except that the length of the outer cylinder 6, the intermediate body 5, and the honeycomb body 4 is also 50 mm. The honeycomb body 4 is disposed on the inlet side of the carrier, the honeycomb body 4 and the intermediate body 5 are brazed in the full length in the axial direction, and the intermediate body 5 and the outer cylinder 6 are brazed in the full length in the axial direction.
[0029]
FIG. 10 shows a known metal carrier E for comparison with the metal carrier of the present invention. Although the dimensions and materials of the respective parts of the metal carrier are the same, the outer diameter of the honeycomb body 4 is 97 mm because there is no intermediate body. The inside of the honeycomb body 10 is joined by brazing in the shaded area. The honeycomb body 10 and the outer cylinder 6 are brazed at a portion 11 in a range indicated by a point near the exit side of the metal carrier, and against thermal expansion and contraction in the radial direction and the axial direction due to exhaust gas having a large temperature change. Since it can be freely deformed, a large thermal stress is hardly generated between the honeycomb body 10 and the outer cylinder 6, and high durability is ensured. However, in order to pattern the joints inside the honeycomb body 10 as shown in the figure, a complicated manufacturing process is required, and there is a problem that the manufacturing cost is increased.
[0030]
FIG. 11 shows a known metal carrier F for comparison with the metal carrier of the present invention. The materials of the outer cylinder 6, the honeycomb body 4, and the intermediate body 12 are the same. Although the size of the outer cylinder 6 is the same as that of the metal carrier A, the intermediate body 12 has a thickness of 150 μm, but only goes around the honeycomb body 4. Similarly, the inside of the honeycomb body 4 is entirely joined by diffusion bonding or brazing in a hatched area, but the honeycomb body 4 and the intermediate body 12 are in the vicinity 13 of the carrier entrance side, and the intermediate body 11 and the outer body 12 are joined together. The cylinder 6 is joined at the exit side vicinity 14. The structure is such that the thermal expansion and contraction in the radial direction of the honeycomb body 4 of the metal carrier F due to the temperature change of the exhaust gas escapes due to the bending of the intermediate body 12.
[0031]
The relative manufacturing costs of these various metal carriers were compared, and in order to evaluate the durability, they were mounted on the exit side of a 4-cycle engine with a displacement of 2000 cc, and a thermal cycle test as shown in FIG. 12 was performed.
In the figure, the vertical axis represents temperature, the horizontal axis represents time, and the temperature measurement is performed at a position 20 mm from the upstream end face of the metal carrier, Temp1 = 150 ° C., Temp2 = 900 ° C., T1 = 10 min, T2 = 10 min. . The number of test cycles to be achieved is 1000, but the test cycle number was extended to 1500 cycles for relative evaluation of durability.
[0032]
The production cost comparison and the durability test results are shown in Table 1.
The number of cycles until the honeycomb body is detached from the outer cylinder is shown. In addition, the determination was accepted if it could withstand 1000 cycles.
[0033]
[Table 1]

[0034]
As described above, each of the various metal carriers of the present invention and the conventional various metal carriers for comparison passed the durability test, but the conventional metal carrier F lacks the degree of freedom of deformation of the intermediate and is relatively durable. Is low. In addition, although the metal carrier E showed good durability, there is a disadvantage that the manufacturing cost is high because the manufacturing process is complicated.
In contrast, the metal carriers A 1 , C, and D of the present invention have a balance between durability and manufacturing cost, and are comprehensively superior to conventional metal carriers.
[0035]
【The invention's effect】
As described above, according to the present invention, it has been found that by rationalizing the structure of the metal carrier, it is possible to supply a metal carrier having excellent durability at low cost.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an appearance of a metal carrier of the present invention.
FIG. 2 is an external perspective view showing an example of each component of the metal carrier of the present invention.
FIG. 3 is a cross-sectional view showing an embodiment (metal carrier A) of the present invention.
FIG. 4 is a sectional view showing an example of the present invention (metal carrier C).
FIG. 5 is a sectional view showing an example of the present invention (metal carrier D).
FIG. 6 is a cross-sectional view of a metal carrier showing an embodiment of the present invention.
FIG. 7 is a cross-sectional view of a metal carrier showing an embodiment of the present invention.
FIG. 8 is a cross-sectional view of a metal carrier showing an embodiment of the present invention.
FIG. 9 is a cross-sectional view of a metal carrier showing an embodiment of the present invention.
FIG. 10 is a longitudinal sectional view of a known metal carrier E for comparison with the metal carrier of the present invention.
FIG. 11 is a longitudinal sectional view of a known metal carrier F for comparison with the metal carrier of the present invention.
FIG. 12 is a diagram showing a thermal cycle pattern for evaluating the durability of various metal carriers.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Metal carrier 2 Flat foil 3 Corrugated foil 4 Honeycomb body 5 Intermediate body 6 Outer cylinder 7 Junction part of a honeycomb body and an intermediate body 8 Junction part of an intermediate body and an outer cylinder 9 Non-joint part of an intermediate body 10 Patterning of joining part Honeycomb body 11 Junction part of honeycomb body and outer cylinder 12 Intermediate body 13 Junction part of honeycomb body and intermediate body 14 Junction part of intermediate body and outer cylinder

Claims (4)

  After forming a honeycomb body in which flat foil and corrugated foil are alternately wound or laminated, an intermediate body is formed by winding a thin plate that is the same as or thicker than the foil on the outer side twice or more. And the outer surface of the honeycomb body are continuously rounded and joined in the full length in the axial direction. A metal carrier characterized by being provided.   2. The metal carrier according to claim 1, wherein the whole inside of the honeycomb body is joined.   3. The metal carrier according to claim 1, wherein the intermediate body is a flat plate not corrugated. The metal carrier according to claim 1 or 2 , wherein the corrugated intermediate plate is used.

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