JPH075096A - Evaluating method for metal carrier - Google Patents

Abstract

PURPOSE:To accurately evaluate a connected state of a metal carrier in a short time by pressurizing the carrier placed on a conical stepped supporting base by a conical stepped punch and detecting a reaction force to be applied to the punch and its moving distance. CONSTITUTION:When a stepped part 7 of a metal carrier 1 for receiving only an outer cylinder 2 and the carrier 1 placed on a conical bearer 6 having a stepped part 8 in which a diameter is reduced by each twice of a wave height of a wavy foil of a honeycomb of the carrier 1 are pressurized from above by a conical punch 9, a shearing force is made to at between layers of the honeycomb. Since its peripheral length approaches an outer diameter, it is larger, and hence a shearing part is increased toward the center. Accordingly, if connected states of the layers of the honeycomb are the same, if it is pressurized by the punch 9, it is sequentially damaged from the center. Then, when a connected part of the pressurized and deformed carrier 1 is observed, propriety of the connected state of the honeycomb can be easily judged. Since a reaction force and a displacement at the time of processing are decided in response to the connected state, a connecting degree can be judged from data of a display recorder 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating a metal carrier for purifying exhaust gas discharged from an internal combustion engine such as an automobile engine.

[0002]

2. Description of the Related Art Conventionally, ceramic catalytic converters have been used to purify exhaust gas from passenger cars and the like, but recently, the use of metal carriers has increased due to heat resistance, low pressure loss and mountability. . Metal carrier has a thickness of 50μ
A flat foil made of a metal having corrosion resistance and heat resistance such as about m of stainless steel and a corrugated corrugated foil are spirally wound or alternately laminated to form a honeycomb body, This is housed in an outer cylinder made of corrosion-resistant and heat-resistant metal such as stainless steel. Further, the inside of the honeycomb body and the joining of the honeycomb body and the outer cylinder are joined by known techniques such as brazing, electron beam, laser beam, resistance welding or diffusion joining.

This metal carrier is loaded with a catalyst for purifying exhaust gas such as platinum, palladium and rhodium, and then mounted and used in an exhaust gas system of an automobile engine, for example. Therefore, during operation, the metal carrier is subjected to severe heat cycles from the temperature of the atmosphere to a high temperature exceeding 900 ° C., vibration due to high-speed exhaust gas flow, and severe vibration from the road surface or the vehicle body.

Since the metal carrier is attached in series to the exhaust system of the automobile, if damaged, the exhaust system may be closed or
The debris may flow backwards and be sucked into the engine, destroying the engine and causing a serious accident. It must not be damaged. Therefore, it is necessary to surely bond the inside of the honeycomb body and the honeycomb body to the outer cylinder, and to use a product whose joint is surely evaluated.

In the conventional method for evaluating a joint portion of a metal carrier, for example, when a brazing method is adopted for joining, the metal carrier portion to be inspected is embedded in a resin and its cross section is polished,
The joint was observed and evaluated with an optical microscope. However, this method has a problem that the reliability is poor, the efficiency is low, and the cost is high unless the number of cross sections to be observed is large. Moreover, this method has a problem in that the number of cross sections to be observed is very limited, and the whole carrier cannot be evaluated. Furthermore, in the case of interfacial bonding such as diffusion bonding and resistance welding, the joint is bonded only on the surface of the body to be bonded, and since there is no special bonding material, there is no change in the external shape, so the bonding judgment is extremely difficult. Had a difficult problem.
Further, JP-A-4-140657 discloses a method of pressurizing a metal carrier in a container filled with water, detecting an AE signal generated from an incompletely joined portion, and evaluating the joining state. , The detection accuracy is not satisfied.

[0006]

SUMMARY OF THE INVENTION The present invention is a jig having a special shape in view of the fact that the evaluation of the conventional metal carrier is inefficient, costly, and requires a high degree of skill. The present invention provides a simple evaluation method in which a metal carrier is supported by, and the metal carrier is pressed by a punch having a special shape, and based on the fracture state or load displacement characteristics.

[0007]

SUMMARY OF THE INVENTION The gist of the present invention is to place a metal carrier on a conical stepped support and press the metal carrier axially with a conical stepped punch from the opposite direction of the support. , A metal carrier evaluation method characterized by detecting the reaction force applied to the punch and the amount of movement of the punch, and evaluating the joining state of the metal carrier from the load displacement characteristics.

The present invention will be described in detail below. FIG. 1 is an external view showing the carrier evaluation method of the present invention. The metal carrier 1 is placed on a conical stepped pedestal 6, and a conical stepped punch 9 is installed facing the pedestal 6. The metal carrier 1 on the pedestal 6 is indicated by an arrow P by a press not shown. Then, the bonding state of the metal carrier 1 is evaluated.

As shown in FIG. 2, the metal carrier 1 is composed of an outer cylinder 2, a flat foil 3 and a corrugated foil 4 wound around one axis to form a honeycomb body 5. The outer surface of the honeycomb body 5 is bonded to the inner surface of the outer cylinder 2, and the flat foil 3 and the corrugated foil 4 are bonded to each other by a known method such as brazing or diffusion bonding. The corrugated foil 4 is obtained by corrugating the flat foil 3, and the height of the corrugated foil is determined according to the cell density of the honeycomb body 5. For example, the flat foil 3 and the corrugated foil 4 have a thickness of 50 μm and a cell density of 400 cells / inch ^2.
, The wave height h is 1.22 mm and the pitch is 1.27
mm.

The pedestal 6 has a stepped portion 7 for receiving only the outer cylinder 2 of the metal carrier 1, and the wave height h of the corrugated foil 4 is below the stepped portion 7.
Is provided with the stepped portion 8 whose diameter is reduced by twice each, and has a conical recessed shape. The stepped portion is provided according to the number of layers of the honeycomb body to be evaluated. The outer diameter of the punch 9 is smaller than the inner diameter of the outer cylinder 2, and a stepped portion 10 having a diameter smaller by twice the wave height h of the corrugated foil 4 is provided below the punch 9 and is tapered in a conical shape. . The height of the steps of the stepped portions 7 and 8 of the pedestal 6 is at least higher than the height of the stepped portions of the punch 9 so that the honeycomb body 5 is not crushed by the punch 9 even if the honeycomb body 5 is displaced between the layers. .

The diameter of each stepped portion of the cradle 6 is set to the wave height h.
The reason for making the size smaller by 2 times is that when the layers of the honeycomb body are deviated, the honeycomb body is supported by the inner layer portion,
This is because it is possible to newly evaluate the bonding state inside the layer. However, if the evaluation can be performed more roughly, the widths of the stepped portions of the pedestal 6 and the punch 9 may be increased and the several layers may be collectively supported or pressed. Reference numeral 11 is a pressure force of the punch 9, in other words, a load cell for measuring the reaction force of the metal carrier 1, 12 is a displacement meter for measuring the displacement of the punch 9, and 13 is a load cell 1.
1 is a display recording device that measures the output of the displacement meter 1 and the displacement meter 12.

The metal carrier 1 is mounted on the cradle 6 having the above-described structure.
Then, the metal carrier 1 is pressed by the punch 9 from above.
Although a shearing force acts between the layers of the honeycomb body 5, the shearing force increases toward the center because the circumferential length increases as the outer diameter approaches. Therefore, if the bonding state of each layer of the honeycomb body 5 is the same, the punch 9
When the pressure is applied by, the honeycomb body 5 is sequentially destroyed from the central portion.

The joining state of the honeycomb body 5 can be easily judged by observing the joined portion of the metal carrier 1 which has been deformed under pressure, whether it is good or insufficient. Further, since the reaction force and the displacement at the time of processing are determined according to the joining state of the honeycomb body 5, the joining degree can be judged from the data of the display recording device 13.

If there is a defective bonding portion between some of the layers of the honeycomb body 5, destruction up to a layer having a bonding strength lower than the bonding strength progresses, but a bonding failure does not occur from a layer having a bonding strength higher than that. Jump to the part and destroy it. However, since the punch 9 is stepped, even if the punch 9 is invaded in the defective joint portion, the stepped portion having a diameter larger than that presses the honeycomb body 5 anew and the evaluation test can be continued again. Further, there is a large defective joint near the outer layer, and even if the defective joint comes off at the beginning of the evaluation test, the evaluation test can be continued because it is newly supported by the stepped portion having a small diameter of the pedestal 6. The state of the gap between the layers of the honeycomb body 5 is output as the data of the load displacement of the display recording device, so that the joining state of the metal carrier 1 can be determined.

[0015]

EXAMPLE The results of comparison between the conventional evaluation method and the evaluation method according to the present invention for the diffusion-bonded metal carrier produced under the same conditions are shown.・ Evaluation carrier size: outer diameter 100 mm, length 100 mm Outer cylinder: outer diameter 100 mm, length 100 mm, plate thickness 1 mm Honeycomb: outer diameter 98 mm, length 100 mm Corrugated foil: plate thickness 50 μm, width 100 mm, wave height 1.25
mm, pitch 2.54 mm flat foil: plate thickness 50 μm, width 100 mm Bonding: outer cylinder / honeycomb body and honeycomb body overall diffusion bonding ・ Evaluation punch and pedestal punch of the present invention Maximum stepped portion Outer diameter 96 mm Minimum stepped portion 26mm Outer diameter reduction pitch 5mm Number of steps 35 Steps 2mm Receiving stand Maximum hole diameter 100.5mm Minimum hole diameter 50.5mm Hole diameter reduction pitch 5mm Number of steps 25 Steps 2.5mm ・ Evaluation results

[Table 1]

As a result of evaluation of the metal carrier according to the method of the present invention, the load displacement characteristics in the case of good joining are shown in FIG. 3 and the load displacement characteristics in the case of insufficient joining are shown in FIG. In FIG. 3, the load rises in the initial stage of pressurization, and the displacement gradually drops as the displacement increases, but rises again without a sharp drop. This is because there is no defective joint between the layers of the honeycomb body 5 and the honeycomb body 5 is deformed as a whole. In the case of FIG. 4, the load sharply drops at the initial stage of pressurization, and a sharp drop occurs as the displacement progresses. This is because delamination occurred inside the honeycomb body 5 and the load dropped sharply. In addition, in the broken state of the metal carrier 1 after the test, if there is a defective joint portion, an opening is generated in the same portion, and the quality can be easily judged. Although only the load displacement was monitored as the basis of the evaluation method of the present invention, the application of the present invention is to apply the data processing by the combination of the displacement speed and the nondestructive inspection method to make a judgment. Although the bonding is mainly described in the case of diffusion bonding, it is also effective for various bonding methods including brazing.

[0017]

As described above, according to the present invention, the time and cost can be reduced as compared with the conventional metal carrier evaluation method,
Furthermore, since the structure is evaluated, the bonding state of the metal carrier can be evaluated accurately.

[Brief description of drawings]

FIG. 1 is a three-dimensional sectional view showing a method of the present invention.

FIG. 2 is a sectional structural view of a metal carrier.

FIG. 3 is a load displacement diagram of a metal carrier having a good joint.

FIG. 4 is a load characteristic diagram of a metal carrier having an insufficient joint.

[Explanation of symbols]

 1 metal carrier 2 outer cylinder 3 flat foil 4 corrugated foil 5 honeycomb body 6 pedestal 7 stepped portion 8 stepped portion 9 punch 10 stepped portion 11 load cell 12 displacement gauge 13 display recording device P metal arrow indicating the pressing direction

Claims (1)

[Claims] 1. A metal carrier is placed on a conical stepped support, and the metal carrier is axially pressed by a conical stepped punch from a direction opposite to the support, the reaction force applied to the punch and the punch A method for evaluating a metal carrier, which comprises detecting the amount of movement and evaluating the joining condition of the metal carrier from the displacement load characteristics.