JP4719648B2 - Ceramic honeycomb buffer holding member - Google Patents

Description

  The present invention is directed to a ceramic honeycomb catalyst carrier incorporated in a catalytic converter installed in an exhaust passage through which exhaust gas is passed in order to treat harmful substances contained in exhaust gas discharged from an automobile engine, and DPF (Diesel Particulate). The present invention relates to an improvement in a ceramic honeycomb buffer holding member for holding a honeycomb incorporated in a filter) in a casing.

Exhaust gas discharged from an automobile engine contains harmful substances such as nitrogen oxides (NO _x ), carbon monoxide (CO), and hydrocarbons (HC). If these harmful substances are diffused into the atmosphere as they are, they will cause various pollution such as photochemical smog. Therefore, the exhaust gas is widely detoxified by a catalytic converter provided in the exhaust path. . Such a catalytic converter incorporates a catalyst attached to the surface of a catalyst carrier in which a ceramic is formed in a honeycomb shape. Such a catalyst support made of ceramic is very brittle because it is made of a thin ceramic material, which originally has poor toughness, and is easily damaged by vibration and impact. For this reason, it is necessary to support the catalyst carrier in a buffering manner inside the casing constituting the catalytic converter. Such a structure for supporting the catalyst carrier in a shock-absorbing manner inside the casing is well known, for example, as described in many documents such as Patent Documents 1 to 3.

  FIG. 6 shows an example of the structure of a catalytic converter that has been generally implemented conventionally. The casing 1 has an exhaust inlet 2 on one end side and an exhaust outlet 3 on the other end side. Of these, the exhaust gas sent into the casing 1 from the exhaust inlet 2 is passed through the micro flow path provided in the honeycomb catalyst carrier 4 held in the middle part of the casing 1 and adhered to the inner surface of the micro flow path. After detoxification treatment based on contact with the catalyst, it is sent out from the exhaust outlet 3. Between the outer peripheral surface of the honeycomb catalyst carrier 4 and the inner surface of the casing 1, outer diameter side cushioning materials 5 and 5 called supporters and a shielding ring 6 called an interlam mat are provided. Outer diameter side shock absorbing materials 5 and 5 are formed in a wire mesh shape in which elastic metal filaments are braided into a corrugated shape, and the honeycomb catalyst carrier 4 is supported in the casing 1 so as to be able to absorb a shock in the radial direction. Has a role to play. Further, the shielding ring 6 does not have air permeability, and the exhaust gas bypasses between the outer peripheral surface of the honeycomb catalyst carrier 4 and the inner peripheral surface of the casing 1 (passes without being detoxified by the catalyst). It has a role to prevent this.

  Further, the outer peripheral edge portions of both end surfaces in the axial direction of the honeycomb catalyst carrier 4 are supported in a buffering manner by the buffer holding members 7 and 7 which are objects of the present invention. Both the buffer holding members 7 and 7 are configured as shown in FIG. 8 by connecting a buffer material 9 and a holding ring 8 as shown in FIG. Of these, the buffer material 9 is formed in an annular or string-like shape that is elastically compressible by gathering metal filaments having elasticity and heat resistance, such as stainless spring steel, in a finely bent state. . For example, a metal mesh formed into a cylindrical shape by knit knitting is cut into a predetermined length and then compressed in the axial direction to form an annular shape (including not only a circular shape but also an oval shape and an elliptical shape) in many cases. . Alternatively, there is a case where a wire net obtained by braiding the filament is compressed into a string shape and then cut into a predetermined length and then rounded. In the former case, since it is formed in an annular shape in advance, it is easy to perform a combination work to form the buffer holding member 7 in combination with the holding ring 8. On the other hand, in the latter case, since a plurality of types of buffer holding members 7 having different diameters can be made from the same type of material, the procurement cost of the parts can be reduced. Therefore, which structure is adopted is determined by design considerations.

On the other hand, the holding ring 8 is formed by bending a heat-resistant metal plate such as a stainless steel plate, and includes a substrate portion 10, an inner diameter side flange portion 11, and an outer diameter side flange portion 12. Among these, the board | substrate part 10 is a cyclic | annular flat plate shape as a whole. The inner diameter side flange portion 11 has a cylindrical shape and is bent over the entire circumference from the inner peripheral edge of the substrate portion 10 toward one side in the axial direction. Further, the outer diameter side flange portion 12 is bent over the entire circumference in the same direction as the inner diameter side flange portion 11 from the outer peripheral edge of the substrate portion. Width W ₁₁ in the axial direction of the both flange portions 11, 12, W ₁₂ are different from each other. Specifically, the width W ₁₂ of the outer diameter flange portion 12 is made larger than the width W ₁₁ of the inner diameter side flange portion _{11 (W 12> W 11)} .

  Such a retaining ring 8 and the cushioning material 9 include the cushioning material 9 as a part of the retaining ring 8, the outer peripheral surface of the inner diameter side flange portion 11 and the inner peripheral surface of the outer diameter side flange portion 12. In the portion between the two, they are disposed along the substrate portion 10 and are coupled to each other. In this state, a part of the cushioning material 9 is protruded in the axial direction from the tip edge of the inner diameter side flange portion 11. In a state where the catalytic converter is assembled, a part of the buffer material 9 that protrudes in the axial direction from the tip edge of the inner diameter side flange portion 11 is formed on the outer peripheral edge portion of the axial end surfaces of the honeycomb catalyst carrier 4. In spite of this, regardless of the axial vibration or impact applied between the honeycomb catalyst carrier 4 and the casing 1, damages such as chipping may occur at the outer peripheral edge portions of the both end surfaces in the axial direction of the honeycomb catalyst carrier 4. To prevent.

Conventionally, spot welding has been adopted in order to connect the holding ring 8 and the buffer material 9 constituting the buffer holding member 7 described above. That is, as shown in FIG. 9 (A) → (B), a part of the cushioning material 9 is crushed and a plurality of circumferential locations (3 to 4 locations) of the cushioning material 9 are placed in the holding ring 8. The substrate portion 10 was spot welded.
However, the heat capacity of the cushioning material 9 formed by braiding filaments having a small wire diameter and the heat capacity of the holding ring 8 having a plate thickness sufficient to ensure the required rigidity differ greatly from the degree of melting caused by heating. Is also very different. Therefore, the operation of welding the holding ring 8 and the cushioning material 9 becomes difficult even when these members 8 and 9 are made of the same kind of metal. In order to perform such difficult welding, dedicated equipment and troublesome process management are required, which increases the manufacturing cost of the buffer holding member 7.
In addition, since the buffer material 9 is partially crushed in the circumferential direction, the shape of the buffer material 9 is distorted as shown in FIG. Specifically, a portion of the cushioning material 9 that deviates from the spot welded portion in the circumferential direction rises from the substrate portion 10 of the holding ring 8. If the degree of the rise becomes significant, the buffer material 9 and the inner diameter side flange portion 11 may interfere with the outer diameter side flange portion 12 when the catalytic converter is assembled. . When the interference occurs, the cushioning material 9 and the substrate portion 10 of the holding ring 8 cannot be brought into contact over the entire circumference, and the catalytic converter cannot be assembled in a normal state.

JP 7-279655 A JP-A-9-195759 JP 2001-300228 A

  In view of the circumstances as described above, the present invention has been invented to realize a structure that does not require an expensive manufacturing facility and can easily and reliably perform the coupling between the retaining ring and the buffer material. .

The ceramic honeycomb buffer holding member of the present invention is in a state where the metal plate holding ring and the elastic metal filament are finely bent in the same manner as the conventionally known ceramic honeycomb buffer holding member. By gathering, it is made of an elastically compressible annular or string-like cushioning material.
Further, the holding ring is a flat plate-like annular (including not only circular, but also oval, elliptical) substrate portion, an inner diameter side flange portion bent from the inner peripheral edge of the substrate portion toward one side in the axial direction, An outer-diameter flange portion having a larger axial dimension than the inner-diameter flange portion, which is bent in the same direction as the inner-diameter flange portion from the outer peripheral edge of the substrate portion.
And the said buffer material is couple | bonded with the said holding | maintenance ring in the state arrange | positioned along the said board | substrate part in the part between this outer diameter side flange part and the said inner diameter side flange part.

In particular, in the ceramic honeycomb buffer holding member of the present invention, at least a part of at least one of the outer diameter side flange part and the inner diameter side flange part is opposed to the other flange part. There are provided locking protrusions that are provided at a plurality of locations (for example, 3 to 4 locations at equal intervals in the circumferential direction) and project toward the other flange portion.
Each of the locking protrusions has a base end portion on the side farther from the substrate portion than the tip end portion, and is directed to the other flange portion as it goes from the base end portion to the tip end portion. Inclined in the direction.
Then, as the cushioning material is pushed between the flange portions, the cushioning material and the retaining ring are brought into engagement by engaging a part of the cushioning material with the locking protrusions. Non-separated.

When carrying out the present invention as described above, for example, as described in claim 2, each of the locking protrusions is formed in an intermediate portion in the axial direction of the outer diameter side flange portion. In this case, a V-shaped, U-shaped, U-shaped or other cut is formed in the axially intermediate portion of the outer diameter side flange portion with the leading edge side of the outer diameter side flange portion open. Then, by bending the inner side of the cut (the part surrounded by two or three sides by the cut) to the inner diameter side of the outer diameter side flange portion, each locking protrusion is formed.
Alternatively, as described in claim 3, each of the locking protrusions is formed at a leading edge of one flange portion of the inner diameter side flange portion and the outer diameter side flange portion. In this case, projecting pieces are formed in a state of projecting from the flange portion at a plurality of circumferential positions at the tip of the flange portion. Then, each of the protruding pieces is turned to the other flange side with respect to the radial direction by turning back more than 90 degrees and less than 180 degrees to form the locking protrusion pieces.

According to the ceramic honeycomb buffer holding member of the present invention configured as described above, an expensive manufacturing facility is not required, and a structure in which the holding ring and the buffer material can be easily and reliably combined is realized. it can.
First, it is possible to eliminate the need for expensive manufacturing equipment by engaging each retaining projection piece with this buffer material, not by spot welding, but by connecting the holding ring and the buffer material. Since each of these locking protrusions can be processed by a general press machine, the cost of manufacturing equipment does not increase.
Further, the above connection can be easily and reliably performed for the following reason. The cushioning material has a large number of gaps inside, and the gaps are also opened on both the inner and outer peripheral surfaces of the cushioning material. Therefore, the cushioning material is placed between the inner diameter side and outer diameter side flange portions. When pushed in, the leading end portion of each locking protrusion bites into the gap. Since each of these locking protrusions is inclined in the direction toward the base plate part and the other flange part as it goes from the respective base end part to the leading end part, the leading end of each locking protruding piece is accompanied by the pushing-in. When the part bites into the gap and further bites, the cushioning material is prevented from displacing in a direction away from the substrate part, and the cushioning material is not distorted. Does not float from the substrate portion of the retaining ring. For this reason, the said coupling | bonding can be performed easily and reliably.

[First example of embodiment]
1 to 4 show a first example of an embodiment of the present invention corresponding to claims 1 and 2. The feature of the present invention lies in the structure of the portion in which the holding ring 8a and the cushioning material 9 constituting the buffer holding member 7a are inseparably connected. Since the basic structure of the retaining ring 8a and the structure and operation of the other parts including the structure of the cushioning material 9 are the same as those of the conventional structure described above, the explanation for the equivalent parts is omitted or simplified. The description will focus on the features of the present invention.

  As shown in FIG. 2 as a whole, the outer diameter side flange portion of the outer diameter side flange portion is arranged at a plurality of circumferentially equidistant positions (four in the example shown) on the inner peripheral surface of the outer diameter side flange portion 12 constituting the holding ring 8a. Locking protrusions 13 and 13 are formed in the axial direction (width direction) intermediate portion so as to protrude radially inward. Each of the locking protrusions 13 and 13 has a base end portion on the distal end edge side of the outer diameter side flange portion 12 and a distal end portion on the proximal end side of the outer diameter side flange portion 12, respectively. It is inclined in the direction in which the amount of protrusion inward in the radial direction increases from the respective base end portions toward the front end portions.

  In order to form each of the locking protrusions 13 and 13 as described above, at the intermediate portion in the axial direction of the outer diameter side flange portion 12, V as shown by a solid line in FIGS. The cuts 14a to 14c such as letter-shaped, U-shaped, and U-shaped are in a state where the distal end edge side of the outer diameter side flange portion 12 is opened (the discontinuous portion of the cut is present on the distal end edge side of the outer diameter side flange portion 12). ). And the inside of this cut | interruption 14a-14c (part surrounded by two or three sides by the cut | interruption centering on the discontinuous part of the said cut | interruption 14a-14c shown by the dashed line in (A)-(C) of FIG. 3), the above-described locking protrusions 13 and 13 are formed by bending the inner diameter side of the outer diameter side flange portion 12 by less than 90 degrees (for example, about 20 to 50 degrees) as shown in FIG. In an actual case, the processing of the cuts 14a to 14c and the bending of the inner portions of the cuts are performed at once (the bending of the locking protrusions 13 and 13 is performed simultaneously with the processing of the cuts 14a to 14c. Do).

  In order to couple the holding ring 8a and the cushioning material 9 as described above, as in the case of the conventional structure described above, as shown in FIG. 7, the two members 8a and 9 are arranged concentrically with each other. From each other. Of these, the buffer member 9 is inserted between both the inner diameter side and outer diameter side flange portions 11 and 12 constituting the holding ring 8 a and pressed against the substrate portion 10. The cushioning material 9 is formed by gathering elastic metal filaments in a finely bent state, and there are a large number of gaps inside, and the gap includes the outer peripheral surface of the cushioning material 9 and the entire surface. It is open evenly. Therefore, when the cushioning material 9 is pushed into the inner diameter side of the outer diameter side flange portion 12, the leading ends of the locking projections 13 and 13 bite into the opening of the gap. Even if the tips of the locking projections 13 and 13 do not bite into the opening of the gap, the outer peripheral surface of the cushioning material 9 is elastically deformed by the tips of the locking projections 13 and 13. The recesses are formed, and the recesses are engaged with the front ends of the locking projections 13 and 13.

  Each of the locking protrusions 13 and 13 is inclined in the direction toward the substrate portion 10 and the radially inward direction from the base end portion toward the tip end portion. As shown in FIG. 1, as shown in FIG. 1, the leading end portions of the locking protrusions 13 and 13 bite into the recesses formed in the opening or the outer peripheral surface of the gap as they are pushed between the portions 11 and 12. . And in the state which digged in, it prevents that the said buffer material 9 displaces in the direction away from the said board | substrate part 10. FIG. In other words, the cushioning material 9 and the holding ring 8a are bonded to each other without separation. Further, in this state, the buffer material 9 is not distorted, and a part of the buffer material 9 is not lifted from the substrate portion 10. For this reason, the said coupling | bonding can be performed easily and reliably. Further, the work of assembling the catalytic converter using the buffer holding member 7a in which the holding ring 8a and the buffer material 9 are combined is not complicated. Of course, since spot welding is unnecessary, an increase in the cost of manufacturing equipment can be suppressed.

[Second Example of Embodiment]
FIG. 5 shows a second example of the embodiment of the invention corresponding to claim 3. In the case of this example, each locking protrusion 13 a is formed at the distal end edge of the outer diameter side flange portion 12. For this reason, in the case of this example, a protruding piece having a tapered shape such as a V shape is formed on the leading end edge of the outer diameter side flange portion 12 so as to protrude from the leading end edge. Then, by turning back such a projecting piece over the inner diameter side of the outer diameter side flange portion 12 by more than 90 degrees and less than 180 degrees (for example, about 130 to 160 degrees), To do. The operation of turning back the protruding piece to form the locking protruding piece 13a may be performed before or after the outer flange portion 12 is bent with respect to the substrate portion 10.

The holding ring 8b and the cushioning material 9 (see FIG. 1) formed with the respective locking protrusions 13a as described above are combined in the same manner as in the case of the first example of the above-described embodiment, and the buffer holding member And In the combined state, each of the locking protrusions 13 a engages with the outer peripheral surface portion of the cushioning material 9. Since the configuration and operation other than the difference in the formation positions of the locking protrusions 13a are the same as those in the first example of the above-described embodiment, redundant description is omitted.
Although it is not necessary to combine the structure of this example with the structure of the first example, it is free to combine them.

Although not shown, the above-described locking protrusion may be formed at the tip edge of the inner diameter flange portion 11 instead of the tip edge of the outer diameter flange portion 12. However, in this case, the protruding piece formed at the tip edge of the inner diameter side flange portion 11 is folded back to the outer diameter side to form the locking protruding piece. Further, when a locking protrusion is formed on the tip edge of the inner diameter side flange portion 11, the locking protrusion and the catalyst alone overlap with each other in the axial direction. The size of the buffer holding member is made sufficiently smaller than the size of the buffer holding member in the axial direction to prevent interference between the buffer holding member and the locking protrusion. If the structure which forms the above-mentioned locking projection piece in the tip edge of the above-mentioned inside diameter side flange part 11, the projection piece used as the origin of this locking projection piece from the metal plate used as the material for making a holding ring, Similarly, when punching an annular intermediate material, it is formed on the inner peripheral edge of the intermediate material. Since the inner diameter side of the intermediate material is a portion that becomes scrap, the yield of the material does not decrease by forming the protruding piece.
Further, the cross-sectional shape of the cushioning material 9 may be a shape in which the width dimension of the portion abutted against the catalyst carrier is gradually narrowed as shown in the figure, or may be a simple rectangle.

  The present invention is not limited to a buffer holding member for holding a ceramic honeycomb catalyst carrier, but to hold a ceramic honeycomb constituting a DPF that collects graphite fine particles discharged from a diesel engine in a casing. The buffer holding member is also a target.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. The perspective view which takes out and shows only a holding ring. The expanded AA sectional view of FIG. FIG. 4 is a view taken in the direction of arrow B in FIG. 3, showing three examples of the shape of a cut for processing the locking protrusion. The fragmentary perspective view of a holding ring which shows the 2nd example of embodiment of this invention. 1 is a schematic cross-sectional view showing an example of a catalytic converter incorporating a ceramic honeycomb buffer holding member that is an object of the present invention. Sectional drawing which shows the holding | maintenance ring and buffer material which comprise the buffer holding member for ceramic honeycombs in the state before couple | bonding. Sectional drawing and the figure seen from the axial direction side of the buffer holding member for ceramic honeycombs comprised combining the holding ring and the buffer material. The partial schematic sectional drawing shown in the state before and behind the coupling | bonding in order to demonstrate the structure which couple | bonds a holding | maintenance ring and a buffer material by spot welding. The partial perspective view which shows the state which the buffer material deform | transformed with spot welding.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 2 Exhaust inlet 3 Exhaust outlet 4 Honeycomb catalyst carrier 5 Outer diameter side buffer material 6 Shielding ring 7, 7a Buffer holding member 8, 8a, 8b Holding ring 9 Buffer material 10 Substrate part 11 Inner diameter side flange part 12 Outer diameter side flange Part 13, 13a Locking protrusion 14a, 14b, 14c

Claims (3)

  It consists of a metal plate holding ring and an elastically compressible annular or string-like cushioning material by gathering elastic metal filaments in a finely bent state. An annular substrate portion, an inner diameter side flange portion bent from the inner peripheral edge of the substrate portion toward one axial direction, and an inner diameter side flange bent from the outer peripheral edge of the substrate portion in the same direction as the inner diameter side flange portion. An outer diameter side flange portion having a larger axial dimension than the portion, and the cushioning material is disposed along the substrate portion at a portion between the outer diameter side flange portion and the inner diameter side flange portion. In the buffer holding member for a ceramic honeycomb bonded to the holding ring in the disposed state, a part of at least one of the outer diameter side flange part and the inner diameter side flange part, and the other Hula Provided with a plurality of locking projections protruding toward the other flange portion, each of the locking projections having a respective base end portion corresponding to a distal end portion thereof. Existing on the side farther from the base plate part and inclined toward the other flange part as it goes from the respective base end part to the tip part, and the cushioning material is interposed between the two flange parts. The ceramic is characterized in that the cushioning material and the retaining ring are non-separably coupled by engaging a part of the cushioning material with each of the locking protrusions as it is pushed in. Buffer holding member for honeycomb.   Each locking protrusion has an inner side of a cut formed in a state in which a distal end edge side of the outer diameter side flange portion is opened at an axially intermediate portion of the outer diameter side flange portion, and an inner diameter side of the outer diameter side flange portion. The buffer holding member for a ceramic honeycomb according to claim 1, wherein the buffer holding member is formed by bending and bending.   Projection pieces formed in a state in which each locking projection piece protrudes from the distal end of the flange portion on the distal end edge of one flange portion of the inner diameter side flange portion and the outer diameter side flange portion with respect to the radial direction. 2. The ceramic honeycomb buffer holding member according to claim 1, which is formed on the other flange side by turning back over 90 degrees and less than 180 degrees.

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