JP2006320903A - Production method for exhaust gas purifying metal carrier, exhaust gas purifying metal carrier and exhaust gas purifying filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method for an exhaust gas purifying metal carrier excellent in productivity, an exhaust gas purifying metal carrier and an exhaust gas purifying device. <P>SOLUTION: The production method for an exhaust gas purifying metal carrier 1 comprises the steps of applying a laser beam from the outer surface of the cylindrical laminates toward the center of the laminates while at least one pair of laminates of alternately overlapping metal-foil band-like corrugated sheets 2 and metal-foil band-like flat sheets 3 are taken up in a cylindrical shape, and fusing portions of metal foil irradiated with a laser beam to bond two-several layers of band-like flat sheet and inner-layer band-like corrugated sheet together or make holes in them. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an exhaust gas purifying metal carrier used in an apparatus for purifying exhaust gas discharged from an internal combustion engine such as an automobile engine, an exhaust gas purifying metal carrier using the method, and a manufacturing method using the same. The present invention relates to an exhaust gas purification filter.

  In an exhaust gas purification apparatus for an internal combustion engine such as an automobile engine or a generator, a metal carrier in which a cylindrical honeycomb body made of the same metal steel material is fitted in a cylindrical casing made of metal steel such as a heat-resistant stainless steel plate Is used.

A conventional metal carrier having such a structure is generally manufactured by winding a flat thin plate made of a strip-shaped metal thin plate and a corrugated thin wave plate on the flat thin plate in a spiral shape. The honeycomb body is inserted into a cylindrical metal casing, and then the contact portion between the flat and corrugated hollow plate having the mesh cross section and the honeycomb body and the casing are brazed, welded, diffusion bonded, etc. It is manufactured by joining by this method. In addition, an exhaust gas purification device having a purification function by coating various catalysts.
Conventionally, as a method not using a wax material, Non-Patent Document 1 shows one mode in which a corrugated plate and a flat plate are joined using a laser. In the technique of Non-Patent Document 1, a contact point between a flat plate and a corrugated plate is spot-welded by controlling the laser irradiation condition timing. However, since the system is complicated, the joining speed is slow, and the productivity is poor, there is a problem in terms of economy.

Prior art document information relating to the present application includes the following.
Japan Society for Automotive Engineers Academic Lecture Preprint No.102-98

  However, in the conventional manufacturing method in which a heat treatment is performed by using a wax material, an expensive wax material and a vacuum heat treatment furnace are required. However, there was a limit to cost reduction due to badness.

  Also, in the case of a metal carrier bonded with a wax material, when the metal carrier is exposed to high temperatures in actual driving, the bonding strength is not sufficient, so that the bonded portion is separated by thermal stress, and the shape of the bamboo shoot (one direction) by the exhaust pressure In some cases, a defect that deforms into a shape protruding in the above-mentioned manner may occur, which is regarded as a problem.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an exhaust gas purifying part made of a hollow body having a mesh-like cross section and a method for producing the same, as an inexpensive and easy method.

  The method of manufacturing an exhaust gas purifying metal carrier according to claim 1 is characterized in that a cylindrical shape is formed by winding a pair of laminates in which strip-like corrugated plates made of metal foil and strip-like flat plates made of metal foil are alternately stacked. A laser beam is irradiated from the outer surface of the laminate toward the center of the cylindrical laminate to dissolve the portion of the metal foil irradiated with the laser beam, and 2 to 2 of the strip plate and the strip corrugated plate in the inner layer It is characterized in that several layers are joined or opened. In this case, it is desirable that the metal foil is a heat-resistant stainless steel foil having a thickness of 30 to 150 μm. Further, it is desirable that the laser light irradiation is performed continuously. Further, it is desirable to irradiate one surface with one or more laser beams.

The exhaust gas purifying metal carrier according to claim 5 is manufactured using the method for manufacturing an exhaust gas purifying metal carrier according to any one of the above.
An exhaust gas purification filter according to a sixth aspect is characterized in that the exhaust gas purification metal carrier according to the fifth aspect is loaded into a cylindrical case, joined to the cylindrical cylinder, and further coated with a purification catalyst.
The exhaust gas purifying filter according to claim 7 is formed by joining the exhaust gas purifying metal carrier according to claim 5 and a cylindrical cylindrical body only at one end portion in the axial direction, and further covering the purifying catalyst. And
The exhaust gas purifying filter according to claim 8 is the exhaust gas purifying metal carrier according to claim 5 loaded in the cylindrical cylinder, and then reducing one end of the cylindrical cylinder, and only the reduced end. The exhaust gas purifying metal carrier and the cylindrical tube are joined and further covered with a purifying catalyst.
The exhaust gas purifying filter according to claim 9 is the exhaust gas purifying metal carrier according to claim 5 loaded in a cylindrical cylinder, the diameter of both ends of the cylindrical cylinder is reduced, and the purification catalyst is further covered. It is characterized by.

  The present invention does not require expensive brazing, which is a conventional joining method, and the joining method is extremely simple, high speed, high productivity, and economical. Further, since a general Ni brazing material is not used as the brazing material, it is desirable from the environmental viewpoint. Since the joint is close to a point joint, the thermal stress at the joint is low even when exposed to high temperatures, and the shape is extremely difficult to collapse. Moreover, since the metal foil has the through holes, the flow path of the exhaust gas becomes long and the purification performance is improved. Therefore, if the purification performance is the same, the length of the filter can be shortened and the weight can be reduced.

  The exhaust gas purifying metal carrier 1 of the present invention is mainly used as a carrier or a filter in a device for purifying exhaust gas discharged from an internal combustion engine such as an automobile engine. The basic configuration is used by fitting in a cylindrical shape into a cylindrical cylindrical body made of a metal plate as described in the prior art.

  The exhaust gas purifying filter of the present invention has a configuration in which the exhaust gas purifying metal carrier 1 produced by the above-described manufacturing method is fitted into a cylindrical cylinder, joined to the cylindrical cylinder, and coated with a purification catalyst. Has been.

Next, an embodiment of the exhaust gas purifying metal carrier of the present invention will be described with reference to FIG. As shown in FIG. 1, a belt-like corrugated plate 2 made of a metal foil sent while applying tension by a spring 8 and a belt-like flat plate 3 made of a metal foil that has passed through a pinch roller 11 are pressed by a receiving roll 6. When alternately winding in a cylindrical shape, the laser 4 is irradiated from the outer surface of the cylindrical laminate toward the center of the cylindrical laminate, and the portion of the metal foil irradiated with the laser 4 is melted. On the other hand, two or several layers of the belt-like flat plate and the belt-like corrugated plate in the inner layer are joined or opened. Although the winding is not shown in the figure, the rotation speed can be controlled by a speed control motor. Winding is carried out in a cylindrical shape in accordance with the size of the exhaust gas purifying metal carrier 1, and the unwound portion and the cylindrical portion of the strip-like corrugated plate 2 and the strip-like flat plate 3 are cut. Winding of the belt-like corrugated plate 2 and the strip-like flat plate 3 was performed by rotating the belt 9 by the torque motor 13. In FIG. 1, the arrows described on the belt-like flat plate, the belt-like corrugated plate, the pinch roller, the metal carrier, and the belt indicate the rotation direction or the traveling direction.
At the time of laser 4 irradiation, the belt-like corrugated plate 2 and the belt-like flat plate 3 are in contact with each other, or the portions where both plates are in close proximity are joined. Moreover, the location where the strip | belt-shaped corrugated sheet 2 and the strip | belt-shaped flat plate 3 are separated is opened both. In this way, during laser irradiation, bonding or opening can be performed simultaneously due to the difference in the distance between the strip corrugated plate 2 and the strip flat plate 3. The heat-resistant stainless steel foil having a thickness of 30 to 150 [mu] m between the strip corrugated plate 2 and the strip flat plate 3 is desirable. If it is less than 30 μm, when it is heated to a high temperature during use, it is deformed by heat and does not function as the exhaust gas purification metal carrier 1. On the other hand, although it can be applied even if it exceeds 150 μm, a high-power laser is required, and the bonding or opening speed is slow, which is uneconomical. Furthermore, it is desirable that the laser light irradiation be performed discontinuously. For example, it is desirable that the irradiation be performed at an interval of 20 to 200 mm from the objective lens. If the distance is less than 20 mm, the distance is too short, and the optical system device such as a lens is easily damaged by heat generated by laser irradiation or reflected laser light. On the other hand, if it exceeds 200 mm, the irradiation position (focal position) becomes unstable due to vibration or the like, and the bonding becomes difficult to stabilize.

It is desirable to irradiate the laser 4 with one or a plurality of stripes simultaneously. This is appropriately selected depending on the size of the exhaust gas purifying metal carrier 1. In addition, by increasing the laser output, laser transmission may not be performed at all for one round, and discontinuous laser irradiation may be intermittently performed for each round for welding.
The exhaust gas purification metal carrier 1 manufactured as described above is loaded into a cylindrical cylinder, joined to the cylindrical cylinder by laser welding, and further coated with a purification catalyst. The exhaust gas purifying metal carrier 1 joins the ends of the cylindrical tube. Further, the exhaust gas purifying metal carrier 1 may be loaded into a cylindrical cylinder and the diameter of one side of the cylindrical cylinder may be reduced as necessary. Further, when the heat load of the exhaust gas purification filter is small, the exhaust gas purification metal carrier and the cylindrical cylinder play a role without being separated by reducing the diameter of both ends of the cylindrical cylinder. By joining only one side, the stress acting on the joint is greatly reduced.

  In addition, this invention is not limited to embodiment mentioned above, A various change is possible as needed. FIG. 2 shows a case where four layers are wound up at the same time, but bonding is possible and efficient. Moreover, as an aspect other than the cylindrical shape, it is possible to alternately laminate flat plates and corrugated plates and join the laminated sections so as to be square. In that case, a metal carrier having a good shape can be obtained by pressurizing at a constant pressure from the upper surface of the plate, irradiating with one to several lasers and bonding. Basically, it is not necessary to braze, but it may be performed on a part of the end face as needed. Moreover, a well-known thing can be used for a catalyst, for example, what carried catalysts, such as platinum and palladium, on the carrying layer which consists of activated alumina can be used.

  The exhaust gas purification filter produced according to the present invention exhibited sufficient purification performance without any problem with respect to pressure loss.

  The present invention does not require expensive brazing, which is a conventional joining method, and the joining method is extremely simple, high speed, high productivity, and economical. Further, since a general Ni brazing material is not used as the brazing material, it is desirable from the environmental viewpoint. Since the joint is close to a point joint, the thermal stress at the joint is low even when exposed to high temperatures, and the shape is extremely difficult to collapse. Moreover, since the metal foil has the through holes, the flow path of the exhaust gas becomes long and the purification performance is improved. Therefore, if the purification performance is the same, the length of the filter can be shortened and the weight can be reduced.

Schematic diagram of the production method of the present invention The figure which shows one embodiment before winding the strip | belt-shaped corrugated sheet and strip | belt-shaped flat plate of this invention.

Explanation of symbols

1 Metal carrier 2 Strip corrugated plate 3 Strip flat plate 4 Laser 5 Frame 6 Receiving roll 8 Spring 9 Belt 11 Pinch roller 13 Torque motor

Claims (9)

  Centering from the outer surface of the cylindrical laminate to the center of the cylindrical laminate while winding up a pair of laminates in which the corrugated plates made of metal foil and the strip-like flat plates made of metal foil are alternately stacked. Exhaust gas purification by irradiating laser beam to melt the portion of the metal foil irradiated with laser beam and joining or opening two or several layers of the strip-like flat plate and the strip-like corrugated plate in its inner layer A method for producing a metal carrier.   The method for producing an exhaust gas purifying metal carrier according to claim 1, wherein the metal foil is a heat-resistant stainless steel foil having a thickness of 30 to 150 μm.   The method of manufacturing an exhaust gas purifying metal carrier according to any one of claims 1 to 2, wherein the laser light irradiation is performed discontinuously.   The method for manufacturing an exhaust gas purifying metal carrier according to any one of claims 1 to 3, wherein at least one of the upper and lower planes is irradiated with one or more laser beams. Production method.   An exhaust gas purification metal carrier produced by using the method for producing an exhaust gas purification metal carrier according to any one of claims 1 to 4.   An exhaust gas purification filter comprising: the exhaust gas purification metal carrier according to claim 5 mounted in a cylindrical cylinder, joined to the cylindrical cylinder, and further coated with a purification catalyst.   An exhaust gas purification filter comprising: the exhaust gas purification metal carrier according to claim 5 and a cylindrical tube joined at only one end portion in the axial direction, and further coated with a purification catalyst.   After the exhaust gas purifying metal carrier according to claim 5 is loaded into a cylindrical cylinder, one end of the cylindrical cylinder is reduced in diameter, and the exhaust gas purifying metal carrier and the cylindrical cylinder are provided only at the reduced end. An exhaust gas purification filter that is joined and further coated with a purification catalyst. An exhaust gas purification filter comprising: the exhaust gas purifying metal carrier according to claim 5 loaded in a cylindrical cylinder, the diameter of both ends of the cylindrical cylinder being reduced, and a purification catalyst being coated. .

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