JPH0636269Y2 - Sealing material for honeycomb catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention relates to a sealing material for a honeycomb catalyst body, which is provided in a casing of an exhaust pipe in an automobile internal combustion engine and is used for purifying exhaust gas. It is about improvement.

"Prior Art" As a conventional sealing material of this type, for example, SAIkai 58-8242
There is one shown in Japanese Patent Publication No. 1.

Although not specifically shown, the conventional sealing material is formed by forming a tubular wire mesh body in which metal fine wires are knitted, and winding a ceramic fiber band around the center of the outer periphery of the cylindrical wire mesh body. By sequentially folding the wire mesh body from both ends to obtain a ring body having a predetermined width so that the fiber band exists in the center, and then compression molding the ring body into an L-shaped cross section, A ceramic fiber band having the same shape is internally provided in the central portion.

In actual use, the sealing material compression-molded to have an L-shaped cross section is fitted in advance to the outer circumferences of both ends of the honeycomb catalyst body, and the honeycomb catalyst body is provided in the casing of the exhaust pipe. For example, the sealing material closes the gap between the outer peripheral surface of the honeycomb catalyst body and the inner wall surface of the casing, whereby unpurified exhaust gas is discharged from the gap between the outer peripheral surface of the honeycomb catalyst body and the inner wall surface of the casing. It is to prevent that.

"Problems to be solved by the invention" However, when manufacturing an existing conventional sealing material, at least a step of forming a relatively large-diameter tubular wire mesh body by knitting metal thin wires such as stainless steel wires A step of separately forming a ceramic fiber band, a step of winding the ceramic fiber band around a central portion of the outer periphery of a tubular wire mesh body, and a step of sequentially folding back both ends of the wire mesh body around which the ceramic fiber band is wound, Finally, the step of compression-molding the entire body into an L-shaped cross section is required independently for each time, so that not only the manufacturing process of the sealing material becomes complicated but also it is required. In addition, the sealing material itself has a big problem that the cost becomes high.

"Means for Solving the Problem" The present invention was developed in order to effectively solve such a conventional problem, and provides a sealing material for a honeycomb catalyst body provided in a casing of an exhaust pipe. As a premise, it consists of a hollow tubular body wound around the outer periphery of the honeycomb catalyst body, and the hollow tubular body is knitted together with metal thin wires to be knitted and knitted together when knitting the metal thin wires. The diameter of the tubular body is made larger than the gap between the inner wall surface of the casing and the outer peripheral surface of the honeycomb catalyst body.

According to the "action", according to the present invention, when the metal thin wire is knitted, the hollow cylindrical body wound around the outer periphery of the honeycomb catalyst body can be easily formed by simply knitting the organic core material together. Therefore, the manufacturing process of the sealing material can be greatly simplified, and the cost can be sufficiently reduced.

In addition, the hollow cylindrical body according to the present invention has a diameter larger than the gap between the inner wall surface of the casing and the outer peripheral surface of the honeycomb catalyst body, and thus the hollow cylindrical body contacts the inner wall surface of the casing and honeycomb. The outer peripheral surface of the medium is compressed and deformed, but its hollow shape is not completely crushed, so
As a result, the cushioning effect can be exerted on the honeycomb catalyst body at all times, while the presence of the organic core material woven together with the fine metal wires completely seals the gap between the outer peripheral surface of the honeycomb catalyst body and the inner wall surface of the casing. Therefore, it is possible to completely prevent the unpurified exhaust gas from being discharged from the gap between the outer peripheral surface of the honeycomb catalyst body and the inner wall surface of the casing.

[Example] Hereinafter, the present invention will be described in detail with reference to an illustrated example. A sealing material according to the example is as shown in FIG. 1A.
The honeycomb tubular body comprises a hollow tubular body 1 cut into a length dimension which is wound around the outer periphery of the honeycomb catalytic body.
As shown in FIG. 2, the metal thin wire 2 to be knitted and the organic core material 3 to be knitted together when the metal thin wire 2 is knitted are formed, and the diameter of the hollow cylindrical body 1 will be described later. It is characterized in that it is made larger than the gap between the inner wall surface of the casing of the exhaust pipe and the outer peripheral surface of the honeycomb catalyst body.

Further, in the present embodiment, when the sealing material is manufactured by using the above-mentioned structure, when the metal thin wire 2 such as a stainless steel wire is knitted, it is made of ceramic fiber or the like. It is possible to mold the hollow cylindrical body 1 as the sealing material by a single step of weaving the organic core material 3 together in an extremely dense state.

Therefore, when the sealing material of this embodiment is used, the second
As shown in FIGS. 3A and 3B, a state in which the hollow cylindrical body 1 is wound around the outer periphery of both ends of the honeycomb catalyst body 4 is obtained, and the honeycomb catalyst body 4 is set in the upper and lower split casings 5A and 5B. Then, by welding the flange portions 6 of the split type upper and lower casings 5A and 5B, the honeycomb catalyst body 4 in which the hollow cylindrical body 1 is wound around the outer peripheral portions of both ends is formed into the casings 5A and 5B of the exhaust pipe 7. It will be held securely inside.

When the split casings 5A and 5B are integrated by welding the flange portion 6, as described above, the diameter of the hollow cylindrical body 1 becomes larger than the inner wall surfaces of the casings 5A and 5B and the honeycomb catalyst body 4. Because it is larger than the gap between the outer peripheral surfaces,
The hollow cylindrical shape 1 is compressed by the inner wall surfaces of the casings 5A and 5B and the outer peripheral surface of the honeycomb catalyst body 4, and as shown in FIG. 3, the hollow shape retained by the knitted portion of the thin metal wire 2 is
For example, it deforms into a flat elliptical shape or the like, but it is not completely crushed, so that it is possible to sufficiently exert the elastic cushioning action on the honeycomb catalyst body 4 at all times.

Then, in such a state, the densely knitted organic core material 3 forming the hollow tubular body 1 completely closes the knitting of the knitting of each metal fine wire 2.
Even if the exhaust gas passes through the casings 5A and 5B, the gap between the outer peripheral surface of the honeycomb catalyst body 4 and the inner wall surfaces of the casings 5A and 5B is completely sealed due to the function of closing the stitches by the organic core material 3. , The outer peripheral surface of the honeycomb catalyst body 4 and the casing 5A
It is possible to completely prevent the unpurified exhaust gas from being discharged from the gap between the inner wall surfaces of 5B.

Therefore, the hollow cylindrical body 1 according to the present embodiment has the organic core material 3
In addition to being able to simultaneously exert the sealing action by the knitting and the cushioning action by the knitting of the metal fine wire 2, in the manufacturing process, the step of forming the tubular wire mesh body by knitting the metal fine wire as in the past, and the ceramic fiber band Separately, the step of winding the ceramic fiber band around the outer peripheral center of the tubular wire mesh body, the step of sequentially folding back both ends of the wire mesh body wound with the ceramic fiber band, and finally the entire cross section. No L-shaped compression molding step is required.

"Effects of the Invention" As described above, the sealing material of the present invention comprises a hollow cylindrical body wound around the outer periphery of the honeycomb catalyst body, and the hollow cylindrical body is
A metal thin wire to be knitted and an organic core material to be knitted together when the metal thin wire is knitted, and the diameter of the hollow cylindrical body is defined by the inner wall surface of the casing of the exhaust pipe and the honeycomb catalyst body. Since it is characterized in that it is made larger than the gap between the outer peripheral surfaces, it is possible to extremely effectively provide the sealing effect by the organic core material and the cushioning effect by the knitting of the metal fine wire.

In addition, the sealing material of the present invention can easily manufacture a hollow cylindrical body wound around the outer periphery of the honeycomb catalyst body by simply knitting together the organic core material when knitting fine metal wires. Therefore, compared with the conventional one, the manufacturing process can be greatly simplified, which contributes greatly to cost reduction.

[Brief description of drawings]

FIG. 1A is an external perspective view showing a sealing material of a honeycomb catalyst body according to an embodiment of the present invention, FIG. 1B is an enlarged view of a main part of the sealing material, and FIG. 2 is a hollow cylindrical body wound. FIG. 3 is an exploded perspective view showing a state before holding the honeycomb catalyst body in the casing, and FIG. 3 is a sectional view showing a state in which the honeycomb catalyst body is held in the casing. 1 ... Hollow cylindrical body, 2 ... Metal thin wire, 3 ... Organic core material,
4 ... Honeycomb catalyst, 5A / 5B ... Split casing,
6 ... Flange part, 7 ... Exhaust pipe.

Claims (1)

[Scope of utility model registration request] 1. A sealing material for a honeycomb catalyst body provided in a casing of an exhaust pipe, comprising a hollow cylindrical body wound around an outer periphery of the honeycomb catalyst body, the hollow cylindrical body being a knitted knitted fabric. A fine metal wire and an organic core material that is knitted together when knitting the fine metal wire, and the diameter of the tubular body is set between the inner wall surface of the casing and the outer peripheral surface of the honeycomb catalyst body. A sealing material for a honeycomb catalyst body, characterized in that it is made larger than the gap.