JPH0526143U - Exhaust gas purification device - Google Patents

Abstract

(57) [Abstract] [Purpose] In a metal exhaust gas purification device used under harsh conditions, improve the durability of the honeycomb body, which is the main constituent member, to deformation and damage due to thermal expansion and thermal stress. To do. [Structure] As rectangular wave band material (pitch width P ₁ , wave height H ₁ ) and trapezoidal wave band material (flat portion length L, wave height H ₂ ) made of a thin metal plate used for manufacturing a honeycomb body The honeycomb body is formed by using a material that satisfies the following conditions. (i) 3P ≧ L ≧ P (ii) H ₂ > H ₁

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention generally relates to an exhaust gas purifying apparatus which is a vehicle exhaust gas purifying means and which comprises a metallic honeycomb body for supporting an exhaust gas purifying catalyst, which is interposed in the middle of an exhaust pipe. More specifically, the present invention relates to an exhaust gas purifying apparatus of this type used under severe conditions, which is a metal honeycomb body having improved durability against deformation and damage due to thermal expansion and thermal stress. Is.

[0002]

[Prior Art]

 Conventionally, this type of exhaust gas purifying apparatus generally stacks a flat plate member made of a heat-resistant thin steel plate and a corrugated plate member formed by corrugating the thin steel plate so as to have abutting portions against each other. However, a large number of mesh-like vent holes (hereinafter also referred to as cells) for exhaust gas passages are formed in the axial direction, which are manufactured by stacking them in a spiral shape or stacking them in layers. It is composed of a honeycomb-shaped laminated body having the honeycomb body (hereinafter, referred to as a honeycomb body) and a tubular metal case having both ends opened for filling and fixing the honeycomb body. The honeycomb body and the metal case are isolated from the thermal expansion and thermal stress caused by the high temperature of the exhaust gas itself and the exothermic reaction between the exhaust gas and the purification catalyst, and the vibration and the like when the vehicle is running. It is firmly fixed by brazing or welding so as to obtain it. It goes without saying that the abutting portions of the flat plate-shaped band member and the corrugated plate-shaped band member that form the honeycomb body are fixed by various methods.

Recently, in view of price competition with conventional cordierite-based ceramic carriers, a specially-made metal case for filling and firmly adhering a honeycomb body is not used, That is, there is a movement to construct an exhaust gas purifying apparatus with only a metal honeycomb body. In this case, since the metal case is not used, the manufacturing cost of the metal case, the filling cost of the metal case and the metal honeycomb body, the fixing cost, the so-called canning cost, etc. are reduced, resulting in a significant cost advantage. Needless to say, there is a problem.

However, the above-described conventional exhaust gas purifying apparatus composed only of the honeycomb body or the exhaust gas purifying apparatus composed of the honeycomb body and the metal case cannot endure long-term use. This is not only in the axial direction of the honeycomb body (that is, inflow and passage directions of exhaust gas), but especially in the direction perpendicular to the axial direction (hereinafter referred to as the radial direction of the honeycomb body). Due to the high temperature of the gas itself and the large deformation force due to the thermal expansion and thermal stress that occur in the atmosphere caused by the heat generated by the catalytic reaction of the unburned gas, a large deformation force due to the difference in temperature gradient between the central portion and the outer peripheral portion of the honeycomb body It is based on trying to propagate near the outer peripheral part of the honeycomb body or near the contact surface between the outer peripheral surface of the honeycomb body and the inner wall surface of the metal case through the constituent members (flat plate and corrugated band material). . Immediately, during the process of propagation of the thermal deformation force, the constituent members of the honeycomb body are damaged or buckled, and further, the thermal deformation force is particularly near the outer peripheral portion of the honeycomb body or the outer peripheral surface of the honeycomb body and the metal case. Since it concentrates in the vicinity of the contact surface with the inner wall surface of the plate, the flat band material and / or the corrugated plate material forming the honeycomb body is greatly cracked, damaged, and buckled at the relevant portion. This is due to the drawback that peeling or separation of the abutting portions between them or the abutting portions between the honeycomb body and the metal case occurs.

The following measures have been proposed as measures for improving the durability of the honeycomb body due to the thermal deformation force, particularly in the radial direction.

(I) In Japanese Patent Laid-Open No. 63-182038, a honeycomb body is manufactured from a first corrugated plate and a second corrugated plate having mutually different wavelengths (cycles) λ and wave heights (amplitudes) A. The technology is disclosed. That is, by using a first corrugated plate having a relatively large period and amplitude and a second corrugated plate having a relatively small period and amplitude, radial pressing and stretching under a thermal deformation cycle are performed. I try to endure my strength. However, this technique is based on the premise that the first and second corrugated plates have sinusoidal curves or curves close to them, and when these substantially sinusoidal waveforms are used, the honeycomb body is formed by winding molding or the like. When manufacturing, inconvenience occurs due to lack of rigidity. For example, the waveform is deformed during the winding operation, and it is not possible to manufacture a product with a predetermined cell density (standard product), or the productivity of the honeycomb body is low in relation to the winding speed. In addition, when these corrugated plates are used, the contact portions of the first and second corrugated plates do not all come into contact with each other at the peaks and the peaks (valleys and valleys) or the peaks and valleys (note that this kind of Needless to say, the contact relationship is not preferable for securing the strength of the contact part.) Even if the contact part is fixed by brazing, etc. Thus, the corrugated sheets cause mutual peeling, and various defects are induced in association with such peeling.

(Ii) Japanese Patent Application Laid-Open No. 64-30651 discloses a flat plate in which a concave curved surface portion that comes into surface contact with the convex curved surface portions (wave peaks and troughs) of the corrugated sheet is formed. Seed as corrugated sheet) and a corrugated sheet, a technique for manufacturing a honeycomb body is disclosed. This directly improves the bonding strength and saves the amount of expensive γ-alumina used during washcoating by directly contacting both plates with their respective convex / concave curved surfaces (internal / external contact). It was a bad thing. However, since the flat plate has a corrugated shape, the corrugated portion can reduce the thermal deformation force in the radial direction. However, this technique also uses the corrugated plate having a sinusoidal curve, and thus has the above-mentioned drawbacks due to insufficient rigidity when manufacturing a honeycomb body, and the flat plate and corrugated plate contact surfaces are in surface contact with each other. It has the drawback that the absorption and relaxation characteristics of the dynamic deformation force are reduced.

(Iii) Japanese Utility Model Application Laid-Open No. 2-150032 discloses a metal catalyst carrier having a structure in which a small wave plate having a large number of small waves and a flat wave plate having a flat wave top are alternately stacked. , The wave size of a wave plate is such that two or more abutting flat heads of a flat wave plate are shown. The purpose of this invention is to prevent the film out phenomenon (scoping) in the axial direction of the honeycomb body in particular, but the small wave shape of the small wave plate is a sine wave and the pitch width (one wavelength) is Since it is small, it is difficult to manufacture the small wave plate itself, the corrugation stretches completely when manufacturing the honeycomb body, or clogging occurs in the small wave space during brazing or catalyst coating. There are various problems such as increasing back pressure.

[0009]

[Problems to be solved by the device]

 As described above, in the exhaust gas purifying gas device of this type, in order to sufficiently withstand the thermal deformation force of the honeycomb body, in particular, the flat plate-shaped strip material and the corrugated plate-shaped strip forming the honeycomb body are used. It is necessary to revise the idea that it is only necessary to firmly bond the material and the outer peripheral surface of the honeycomb body to the inner wall surface of the metal case. The present inventor has conducted earnest studies to solve the above-mentioned drawbacks of the conventional exhaust gas purifying device. As a result, instead of the conventional members (flat plate-shaped band member and corrugated plate-shaped band member) that form the honeycomb body, the flat band member is a band member having a rectangular wave with a relatively small wave height (hereinafter, rectangular wave band). And a corrugated strip having a trapezoidal wave with a relatively large wave height (hereinafter referred to as a trapezoidal strip), a uniform cell density with a predetermined cell density. In addition to the process advantage that the honeycomb body can be efficiently manufactured, the present invention was completed by discovering that large deformation force due to thermal expansion and thermal stress transmitted in the radial direction of the honeycomb body can be efficiently absorbed and relaxed. Came to do.

[0010]

[Means for solving problems]

The present invention can be summarized as follows. The present invention is a rectangular wave band material having a pitch width P ₁ and a wave height H ₁ made of a thin metal plate, and a flat portion length L and a wave height H made of a thin metal plate. A honeycomb body for supporting an exhaust gas purifying catalyst having a number of mesh-like vent holes formed in the axial direction by stacking _two trapezoidal wave band materials having trapezoidal waves so that they are in contact with each other. In the exhaust gas purifying device, the rectangular wave band member and the trapezoidal wave band member satisfy the condition (i) 3P ₁ ≧ L ≧ P ₁ (ii) H ₂ > H _1. It relates to an exhaust gas purification device.

Hereinafter, the configuration of the present invention will be described in detail. In the present invention, the rectangular wave and the trapezoidal wave are those in which the cross-sectional shape of the wave is formed by connecting the rectangular cross-sectional shape and the trapezoidal cross-sectional shape. In an exhaust gas purifying apparatus using a metal honeycomb body, it is extremely important to have sufficient durability against a deformation force due to thermal expansion or thermal stress (strain). In other words, this type of exhaust gas purifier made of metal is subject to a harsh thermal environment during running as well as the thermal alternating load of the heating / cooling cycle that is observed during operation, stop, and restart. The problem of durability against heat is a very important issue.

Considering the situation during running, the exhaust gas purifying apparatus was loaded on the difference in the flow rate distribution of the exhaust gas (the difference in the flow rate between the central portion and the peripheral portion) and the surface portion of the honeycomb body. Due to the contact reaction (exothermic reaction) between the exhaust gas purifying catalyst such as Pt, Pd, and Rh and the exhaust gas, the central portion of the honeycomb body is exposed to a higher temperature than the peripheral portion. By the way, the temperature in this type of exhaust gas purification device is generally 700 to 800 ° C, but when the amount of HC (hydrocarbons) is discharged a lot, it reaches around 1200 ° C.

When the temperature gradient inside the honeycomb body is examined in more detail, the temperature gradient between the outer peripheral portion of the honeycomb body and a portion slightly inside thereof is significantly larger than the temperature gradient in the vicinity of the central portion. This is further promoted because the outer peripheral surface of the honeycomb body is in direct contact with the outside air, or the honeycomb body is fixed in the cylindrical metal case in contact with the outside air or rainwater.

Therefore, in an exhaust gas purification device (of a type that does not use a metal case) consisting only of a honeycomb body, or an exhaust gas purification apparatus composed of a honeycomb body and a metal case, the center of the high temperature side of the honeycomb body Strong deformation force (hereinafter also referred to as heat-induced deformation force) due to thermal expansion and thermal response due to heat transfer in the radial direction of the honeycomb body from the portion to the vicinity of the outer peripheral surface of the honeycomb body on the low temperature side. Will also be propagated and concentrated in these areas. The large deformation force due to heat in the radial direction of the honeycomb body causes a temporal change even if the constituent members of the honeycomb body are buckled or the abutting portions between the constituent members are firmly fixed in the propagation process. It causes peeling and also cracks and damages each component. In particular, this effect is large near the outer peripheral surface of the honeycomb body where the thermal deformation force is concentrated. In conjunction with the peeling, cracking, and damage, the expensive catalyst layer carried on the surface of each component also peels off, resulting in a reduction in exhaust gas purification ability. The above situation is the same in an exhaust gas purifying apparatus in which a honeycomb body is filled in a metal case and the outermost peripheral surface of the honeycomb body is firmly fixed to the inner wall surface of the metal case. In this case, the large thermal deformation force breaks the adhered state between the outer peripheral surface of the honeycomb body and the inner peripheral surface of the metal case, thereby inducing the separated state.

Therefore, in order to eliminate or suppress the above-mentioned defects such as peeling, in the structure of the honeycomb body, the deformation force due to thermal expansion or thermal stress in the radial direction of the honeycomb body is effectively absorbed and alleviated. It is essential to take steps.

From the above viewpoints, in the present invention, the following materials are used as constituent members of the metal honeycomb body. (i) Rectangular wave strip having a rectangular wave Instead of a conventional flat strip, a strip made of a thin metal plate and having a rectangular wave with a pitch width P ₁ and a wave height H ₁ is used. (ii) Trapezoidal wave strip having trapezoidal wave Instead of the conventional corrugated plate strip having sinusoidal curve, a strip made of thin metal and having trapezoidal wave with flat portion length L and wave height H ₂ is used. use. Generally, as a honeycomb body of this type, for example, when a honeycomb body having a cell density of 400 cells per square inch (400 cpsi) is manufactured, P ₁ is 0.5 to 1.5 mm depending on the plate thickness of the strip, Rectangular and trapezoidal corrugated strips having 0.2 to 0.5 mm as H ₁ , 0.5 to 1.5 mm as L and 1.0 to 1.5 mm as H ₂ are used.

In the present invention, as the rectangular wave and trapezoidal wave band materials, for example, heat-resistant stainless steel such as chrome steel (chrome 13 to 25%), Fe-Cr 20% -Al 5%, or heat-resistant oxidation resistance In order to improve the above, heat-resistant stainless steel and other flat plate strips with a thickness of 0.02 mm to 0.1 mm are added between the forming gears so that they have a predetermined rectangular wave or trapezoidal wave. What is molded and processed is used. When stainless steel containing Al is used for each strip, the thermal oxidation resistance is improved, and heat treatment causes Al ₂ O _{3 in} various shapes such as whiskers or mushrooms to be extruded on the surface of the strip, which is then exhausted. This is preferable because it firmly fixes the wash coat for supporting the gas purifying catalyst.

In the present invention, the respective strips (rectangular wave strip and trapezoidal strip) are used for the following reasons. That is, the rectangular wave band material having a relatively small rectangular wave can effectively absorb and alleviate the thermal deformation force in the radial direction of the honeycomb body due to the small rectangular waveform (microcorrugation). In addition, since the waveform is a rectangular wave, when a honeycomb body is manufactured together with other trapezoidal wave band materials, the honeycomb body is not deformed more than a sinusoidal waveform material, and a uniform honeycomb body can be manufactured. Furthermore, since the flat portion of the rectangular wave band material can be firmly brazed to the flat portion of the trapezoidal wave band material, a durable honeycomb body can be manufactured. On the other hand, the trapezoidal wave strip having a relatively large trapezoidal wave replaces the conventional corrugated plate strip having a large sinusoidal wave shape, and when the honeycomb body is manufactured, the corrugated shape is not deformed to a predetermined value. The cell shape and cell density can be provided, and the contact portion with the rectangular wave band material having the small rectangular waveform (microcorrugation) can be securely and firmly joined.

In the present invention, in order to exert the full effect under each of the above-mentioned strips, each strip must satisfy the following conditions. That is, in the rectangular wave band material and the trapezoidal wave band material, the condition (i) 3P ₁ ≧ L ≧ P ₁ (ii) H ₂ > H ₁ must be satisfied. Hereinafter, this point will be described with reference to the drawings.

[0020] Figure 1 is a state in which Juseki a rectangular wave strip B _1, a flat portion length L, a trapezoidal wave strip B ₂ wave height H ₂ having a rectangular wave of pitch P _1, wave height H ₁ Is shown. In FIG. 1, the rectangular wave band B ₁ is in contact with the trapezoidal wave band B ₂ for two pitches at the length L flat portion (B ₂₁ ) of the length L of B ₂ , that is, L = The 2P ₁ relationship is shown. In addition, in FIG. 1, it is shown that the length of one pitch of the trapezoidal wave band material B ₂ is P ₂ , and the relationship of the P ₂ to the one pitch length P ₁ of the rectangular wave band material B ₁ is 5P. It is also shown that ₁ = P ₂ . In this type of honeycomb body, it is an extremely important point how many pitches of the rectangular wave band material B ₁ are brought into contact with the flat portion B ₂₁ of the trapezoidal wave band material B ₂ . The reason is that as the pitch width P ₁ of B ₁ is reduced in order to effectively absorb and relax the thermal deformation force, the space S formed by both of them at the contact portion of B ₁ and B ₂ becomes small. This is because, when the brazing of B ₁ and B ₂ is performed, there are adverse effects such as clogging by the brazing material and an increase in exhaust gas back pressure. In this respect, the contact relationship between both strips B ₁ and B ₂ will be considered below. 2, the flat portion B ₂₁ of trapezoidal strip B ₂ (length L), one period length P ₁ of the square-wave strip B ₁ is shown abuts state. That is, the relationship of L = P ₁ is shown. FIG. 3 shows the relationship of L <P ₁ . In such a state, the number of rectangular waves provided in B ₁ is relatively small as compared with those in FIGS. because B ₁ itself is damaged with such excessive thermal stress B _1, further load during manufacture the cross-sectional shape of the space S of the honeycomb body abutment Ryoobizai B ₁ and B ₂ are formed Since it is easily deformed by the winding force and the like, the disadvantages such as the inability to manufacture a honeycomb body having a uniform cell shape become large. Further, when B ₁ having a pitch width P ₁ smaller than that shown in FIG. 1 is used, the brazing filler metal in the space S formed by the abutting portion of both strips B ₁ and B ₂ is used. There arise problems such as clogging and increase in back pressure, and further, the activity of the medium carried in the space S cannot be fully utilized.

From the above viewpoint, in the present invention, the relationship between the pitch width P ₁ of the rectangular wave strip and the length L of the flat portion B ₂₁ of the trapezoidal wave strip is 3P ₁ ≧ L ≧ P ₁ , preferably Holds 2P ₁ ≧ L ≧ P ₁ . In addition, between the wave heights (amplitudes) of both strips, considering the cell density of the honeycomb body, the increase in back pressure, and the ease of manufacturing the strip itself, the condition of H ₂ > H ₁ , preferably 1 It suffices if the condition of / 2H ₂ ≧ H ₁ ≧ 1 / 10H ₂ is satisfied.

The metal honeycomb body of the present invention is manufactured by using the rectangular wave band member having the pitch width P ₁ and the wave height H ₁ and the trapezoidal wave band member having the flat portion length L and the wave height H _2. For example, the one shown in FIGS. 4 to 5 is manufactured by a usual method. That is, as shown in FIG. 4, the honeycomb body (1) comprises a rectangular wave band material (B ₁ ) having a thickness of about 0.03 to 0.1 mm and made of a heat-resistant thin steel plate satisfying the above-mentioned conditions, and a trapezoidal wave. It is manufactured by stacking the strips (B ₂ ) so as to have a contact portion with each other, and then winding and laminating the both in a spiral shape. By this winding lamination, a large number of mesh-like ventilation hole passages (cells) (C) which are passages for exhaust gas are automatically formed. In addition, as shown in FIG. 5, the honeycomb body (1) is formed by stacking rectangular wave strips (B ₁ ) and trapezoidal wave strips (B ₂ ) so that they are in contact with each other, and these are stacked. It may be manufactured by laminating and molding.

In the present invention, the metal case (2) for filling and fixing the honeycomb body (1) inside is not restricted in its shape as long as both ends are open. is not. 4 to 5 show a circular cross section and a race track cross section (oval shape), but the cross section is not limited to this. For example, in order to adapt to the space under the vehicle body, the exhaust gas purification device may be configured using a metal case having a substantially triangular cross section. As the material of the metal case, the same kind of heat-resistant steel as the honeycomb body may be used, or a material having high heat-corrosion resistance may be used. In addition, the outer part of the metal material has a double structure with more heat and corrosion resistance than the inner part, specifically, the inner part is made of flulite stainless steel and the outer part is made of austenitic stainless steel. You may use.

[0024]

【Example】

 Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the examples. (i) Rectangular / trapezoidal band material Fe-Cr 20% -Al 5% -Ce 0.02% heat-resisting steel plate 0.04 mm thick and 74.5 mm wide thin plate strip formed Pass between the gears, ₁ ) And trapezoidal wave band (B₂) Was prepared. That is, the rectangular wave strip (B₁) Pitch width (P₁) Is 0.9 mm, wave height (H₁) Is 0.3 mm, while the trapezoidal wave strip (B₂) Pitch width (P₂) Is 2.4 mm, the length of the flat part (L) is 1.0 mm, and the wave height (H₂) Was set to 1.3 mm. (ii) Manufacture of Honeycomb Body Next, the rectangular wave band material (B₁) And trapezoidal wave band (B₂) Are stacked on top of each other as shown in Fig. 4 and are wound together to form a honeycomb body with an outer diameter of 70 mm, which has a large number of mesh-like ventilation holes (cell density 300 cpsi) in the axial direction. did. When the honeycomb body was manufactured by the winding operation, the trapezoidal shape of the trapezoidal wave band material did not lose its shape, and it was possible to efficiently wind and laminate the trapezoidal band material having a predetermined cell density. Next, the honeycomb body is filled in a metal case made of heat-resistant steel (JIS G4312 SUH310S) with an inner diameter of about 70 mm, and both ends of the honeycomb body and the vicinity thereof (region 10 mm from the end) are nickel-based. It was dipped in a brazing filler metal slurry, dried, and then heat-treated in a vacuum furnace to fix the honeycomb body and the metal case by brazing. Next, the catalyst supporting layer was formed on the exhaust gas purifying apparatus manufactured as described above as follows. That is, the activated alumina (γ-Al₂O₃) A slurry containing powder and alumina sol was applied, and this was heated at 600 ° C. to form a catalyst supporting layer. (Performance evaluation) The exhaust gas purifying apparatus having the above catalyst supporting layer was subjected to a 100-cycle rapid thermal quenching test (burner spalling test) between room temperature and 900 ° C, and a vibration test, and a honeycomb structure. No buckling, cracking, or damage was observed in any part of the member, and neither peeling nor detachment of the contact part was observed. Furthermore, neither fall-off nor peeling of the catalyst-supporting layer was observed.

[0025]

[Effect of the device]

 In the exhaust gas purifying apparatus of the present invention, the honeycomb body part that is exposed to particularly severe thermal conditions has the pitch width and the wave height of the rectangular wave strip having a relatively small rectangular wave as the constituent members. It is manufactured by using a rectangular wave strip and a trapezoidal wave strip having a specific relationship with the flat portion length and the wave height of the trapezoidal wave strip having a large trapezoidal wave. As a result, the honeycomb body of the present invention exerts a thermal deformation force, particularly a large thermal deformation force applied in the radial direction of the honeycomb body, under the cooperation of the rectangular wave band member and the trapezoidal wave band member. Can be effectively absorbed and relaxed. This is because the honeycomb member is made up of a rectangular wave band and a trapezoidal wave band that have a specific relationship, and it is possible to significantly improve the followability to thermal expansion and contraction. It is possible to effectively prevent buckling, cracking, breakage of the constituent members of the honeycomb body and separation of the abutting portion between the members. Further, in the present invention, since the abutting portions of the rectangular wave band material and the trapezoidal wave band material forming the honeycomb body are firmly bonded, the honeycomb body is excellent in vibration resistance and durability. Further, in connection with the above-mentioned effects, the catalyst supporting layer for supporting the exhaust gas purifying catalyst formed on the wall surface of the honeycomb body is effectively prevented from falling and peeling. Furthermore, in the present invention, when a honeycomb body is manufactured, a strip material having a trapezoidal corrugation is used instead of the conventional sinusoidal corrugated corrugated plate as a constituent member thereof. Since the rigidity is higher than that of the corrugated plate having the sinusoidal waveform, the cell shape does not hang up, and it is possible to efficiently manufacture a uniform honeycomb body having a predetermined cell density.

[Brief description of drawings]

FIG. 1 is a diagram showing a first contact relationship between a rectangular wave band member B ₁ and a trapezoidal wave band member B ₂ .

FIG. 2 is a diagram showing a second contact relationship between a rectangular wave band member B ₁ and a trapezoidal wave band member B ₂ .

FIG. 3 is a diagram showing a third contact relationship between a rectangular wave band member B ₁ and a trapezoidal wave band member B ₂ .

FIG. 4 is a perspective view of an exhaust gas purifying apparatus manufactured by fixing the honeycomb body of the present invention in a cylindrical metal case.

FIG. 5 is a perspective view of an exhaust gas purifying apparatus manufactured by fixing the honeycomb body of the present invention in a racetrack-shaped metal case in cross section.

[Explanation of symbols]

1 ・ ・ Honeycomb body B ₁・ ・ ・ Rectangular wave band B ₂・ ・ ・ ・ Trapezoidal wave band C ・ ・ ・ Meshed vent holes (cells) 2 ・ ・ ・ ・ ・Metal case

Claims (8)

[Scope of utility model registration request] 1. A pitch width P ₁ and a wave height H ₁ made of a thin metal plate.
And a rectangular wave strip having a rectangular wave and a trapezoidal wave strip having a trapezoidal wave having a flat portion length L and a wave height H ₂ made of a thin metal plate are stacked so as to be in contact with each other. In an exhaust gas purifying device comprising a honeycomb body for carrying an exhaust gas purifying catalyst having a large number of mesh-like ventilation passages in the axial direction, the rectangular wave band member and the trapezoidal wave band member are (i) 3P ₁ ≧ L ≧ P ₁ (ii) An exhaust gas purifying device which satisfies the condition of H ₂ > H ₁ . 2. The exhaust gas purifying apparatus according to claim 1, wherein H ₁ is 1/2 to 1/10 of H ₂ . 3. The rectangular wave strip and the trapezoidal wave strip are 2P ₁ ≧ L.
The exhaust gas purifying apparatus according to claim _{1, wherein} the condition of ≧ P ₁ is satisfied. 4. The honeycomb body is manufactured by stacking rectangular wave strips and trapezoidal wave strips so that they are in contact with each other, and winding and stacking them in a spiral shape. The exhaust gas purification device according to the item. 5. The exhaust gas purifying apparatus according to claim 1, wherein the honeycomb body is manufactured by stacking rectangular wave strips and trapezoidal wave strips in a layered manner so as to be in contact with each other. 6. The exhaust gas purifying apparatus according to claim 1, wherein the honeycomb body is fixed in a metal case. 7. The exhaust gas purifying apparatus according to claim 6, wherein the metal case has a circular cross section. 8. The exhaust gas purifying apparatus according to claim 6, wherein the metal case has a racetrack cross section.