Gasket and exhaust structure

Abstract

To provide a gasket that is less likely to be worn even when holding an in-pipe component having a surface with irregularities.SOLUTION: A gasket includes: a ring-shaped substrate constituted of an integrated member or a plurality of members comprising an inorganic fiber; and a barrier layer disposed in at least part of the surface of the substrate and including a heat-resistant material.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gasket and an exhaust structure. [Background technology]

[0002] Gaskets are sometimes used to hold components placed inside the exhaust pipe of an automobile (hereinafter simply referred to as "inner pipe components"). Because the inside of an automobile exhaust pipe can become very hot, gaskets are required to be durable as well as to retain their shape.

[0003] As a technique used for such applications, Patent Document 1 discloses a heat-resistant gasket made of inorganic fibers to which a dust-preventing agent is added, while Patent Document 2 discloses a gasket in which alumina-silica fibers and kaolin clay are mixed in a specific ratio to improve heat resistance and shape retention.

[0004] As an internal pipe component that is held in an exhaust pipe by a heat-resistant gasket, Patent Document 3 discloses a heater that is made of a metal honeycomb structure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 6-204202 [Patent Document 2] Japanese Patent Application Publication No. 10-60412 [Patent Document 3] U.S. Patent No. 5,997,503 Summary of the Invention [Problem to be solved by the invention]

[0006] The gaskets described in Patent Documents 1 and 2 exhibit sufficient characteristics when the surface of the internal pipe part is smooth. However, when holding an internal pipe part having an uneven surface, such as the heater made of a metal honeycomb structure described in Patent Document 3, the gasket may be worn down by the unevenness. When the gasket wears down, problems occur such as the inorganic fibers that make up the gasket scattering and a decrease in the ability to hold the internal components of the pipe.

[0007] The present invention has been made to solve the above problems, and has an object to provide a gasket that is resistant to wear even when holding an internal pipe part having an uneven surface. [Means for solving the problem]

[0008] The gasket of the present invention is characterized by comprising a ring-shaped substrate composed of one or more members made of inorganic fibers, and a barrier layer containing a heat-resistant material disposed on at least a portion of the surface of the substrate.

[0009] The gasket of the present invention has a barrier layer including a heat-resistant material disposed on at least a portion of the surface of a substrate, and therefore the barrier layer can prevent direct contact between the inorganic fibers constituting the gasket and the internal component of the pipe, thereby suppressing wear of the gasket.

[0010] In the gasket of the present invention, the heat-resistant material is preferably at least one selected from the group consisting of alumina, zirconia, forsterite, steatite, cordierite, mullite, aluminum titanate, potassium titanate, mica, glass, and silica. When the heat-resistant material is one of the above materials, the heat resistance and mechanical strength are excellent, and wear of the gasket can be stably suppressed.

[0011] In the gasket of the present invention, the surface roughness Ra of the surface of the barrier layer is preferably 0.2 μm to 25 μm. When the surface roughness Ra of the barrier layer is within the above range, the barrier layer is less likely to wear away, and therefore the surface shape of the barrier layer does not need to conform to the irregularities of the object to be protected, making it possible to protect the substrate.

[0012] In the gasket of the present invention, the allowable flatness of the surface of the barrier layer is preferably within the average thickness ±1.5 mm. When the allowable flatness of the surface of the barrier layer is within the above range, the barrier layer is less likely to wear away, and therefore the surface shape of the barrier layer does not have to conform to the irregularities of the object to be protected, making it possible to protect the substrate.

[0013] In the gasket of the present invention, the average thickness of the barrier layer is preferably 0.1 mm to 3 mm. When the average thickness of the barrier layer is within the above range, wear of the gasket can be sufficiently suppressed.

[0014] In the gasket of the present invention, it is preferable that the substrate has a first main surface and a second main surface opposed to each other in a thickness direction, and the barrier layer is disposed on the first main surface. In a substrate having first and second main surfaces opposing each other in the thickness direction, when a barrier layer is disposed on the first main surface, wear of the gasket can be reliably suppressed by positioning the substrate so that the first main surface faces an inner pipe component and then using the gasket.

[0015] In the gasket of the present invention, it is preferable that the substrate has a first main surface and a second main surface opposing each other in the thickness direction, and further has a ring-shaped groove on the inner circumference of the ring, the groove opening into the first main surface and the inner peripheral wall of the ring, and defined by a groove bottom surface parallel to the first main surface and the second main surface and a groove side surface parallel to the inner peripheral wall, and the barrier layer is disposed on the groove bottom surface. By using a base material having a groove of the above shape, it is possible to hold an internal pipe part inside the groove. In this case, the bottom surface of the groove comes into contact with the internal pipe part, but since a barrier layer is disposed on the bottom surface of the groove, wear of the gasket can be reliably suppressed.

[0016] In the gasket of the present invention, it is preferable that the base material is formed into a ring shape by combining a plurality of non-ring-shaped members and has first and second main surfaces opposing each other in the thickness direction, the barrier layer is disposed on the first main surface and is formed into a ring shape by combining a plurality of non-ring-shaped members, and when viewed from the thickness direction, the seams between the members constituting the base material and the seams between the members constituting the barrier layer do not overlap.

[0017] When the substrate is configured so that a plurality of non-ring-shaped members are combined to form a ring shape, and the barrier layer disposed on the first main surface of the substrate is configured so that a plurality of non-ring-shaped members are combined to form a ring shape, the barrier layer that is ring-shaped as a whole is disposed on the first main surface of the substrate that is ring-shaped as a whole. Here, since both the substrate and the barrier layer are composed of multiple non-ring-shaped components and have a ring-like shape as a whole, the substrate and the barrier layer each have a seam between the components at a position that divides the ring. Here, when viewed from the thickness direction, if the seams between the members constituting the base material and the seams between the members constituting the barrier layer do not overlap, it is possible to prevent exhaust gas from leaking through the seams.

[0018] The exhaust structure of the present invention is an exhaust structure comprising an exhaust pipe, an internal pipe component disposed inside the exhaust pipe, and a gasket that fixes the internal pipe component inside the exhaust pipe, wherein the gasket comprises a ring-shaped base material made of inorganic fibers and a barrier layer made of a heat-resistant material disposed on at least a portion of a surface of the base material, the internal pipe component is fixed inside the exhaust pipe by being sandwiched between the two gaskets, the two base materials constituting the two gaskets are each composed of one unit or multiple members, the surface of the internal pipe component that faces the base material has unevenness formed thereon, and the barrier layer is disposed on at least a portion of the surface of the base material that faces the internal pipe component.

[0019] In the exhaust structure of the present invention, a barrier layer containing a heat-resistant material is disposed on at least a portion of the surface of the base material that faces the inner pipe component, so that even if unevenness is formed on the surface of the inner pipe component that faces the gasket, wear of the gasket due to the unevenness can be suppressed.

[0020] In the exhaust structure of the present invention, it is preferable that the two gaskets are a first gasket and a second gasket, a first base material constituting the first gasket has a first main surface and a second main surface opposing each other in the thickness direction, and a second base material constituting the second gasket has a third main surface and a fourth main surface opposing each other in the thickness direction, the first main surface and the third main surface are surfaces facing the inner pipe component, and the barrier layer is disposed on at least a portion of the surface of the first main surface and at least a portion of the surface of the third main surface, respectively.

[0021] In an exhaust structure having the above-described structure, when a barrier layer is disposed on at least a portion of the first and third main surfaces, which are the surfaces facing the inner pipe component, even if unevenness is formed on the surfaces of the inner pipe component that face the first and second base materials, it is possible to prevent the first and second gaskets from being worn away by the unevenness.

[0022] In the exhaust structure of the present invention, the two gaskets are a first gasket and a second gasket, a first base material constituting the first gasket has a first main surface and a second main surface opposed to each other in a thickness direction, and further has a ring-shaped groove on an inner circumference of a ring, the ring opening into the first main surface and an inner circumferential wall of the ring, the ring defining a first groove bottom surface parallel to the first main surface and the second main surface, and a first groove side surface parallel to the inner circumferential wall, and a second base material constituting the second gasket defines a first main surface and a second main surface opposed to each other in a thickness direction. It is preferable that the inner periphery of the ring has a third main surface and a fourth main surface, and further has a ring-shaped groove that opens into the third main surface and an inner circumferential wall of the ring and is defined by a second groove bottom surface parallel to the third main surface and the fourth main surface and a second groove side surface parallel to the inner circumferential wall, the first groove bottom surface and the second groove bottom surface are each surfaces facing the inner pipe component, and the barrier layer is disposed on at least a portion of the first groove bottom surface and at least a portion of the second groove bottom surface, respectively.

[0023] In an exhaust structure having the above-described structure, when a barrier layer is disposed on at least a portion of the surface of the first groove bottom of the first base material, which is the surface facing the inner pipe component, and at least a portion of the surface of the second groove bottom of the second base material, even if unevenness is formed on the surface of the inner pipe component that faces the first gasket and the second gasket, wear of the first gasket and the second gasket due to the unevenness can be suppressed.

[0024] In the exhaust structure of the present invention, it is preferable that neither the second main surface nor the fourth main surface faces the pipe inner part.

[0025] In the exhaust structure of the present invention, the heat-resistant material is preferably at least one selected from the group consisting of alumina, zirconia, forsterite, steatite, cordierite, mullite, aluminum titanate, potassium titanate, mica, glass, and silica. When the heat-resistant material is one of the above materials, the heat resistance and mechanical strength are excellent, and wear of the gasket can be stably suppressed.

[0026] In the exhaust structure of the present invention, the surface roughness Ra of the surface of the barrier layer is preferably 0.2 μm to 25 μm. When the surface roughness Ra of the barrier layer is within the above range, the barrier layer is less likely to wear away, and therefore the surface shape of the barrier layer does not need to conform to the irregularities of the object to be protected, making it possible to protect the substrate.

[0027] In the exhaust structure of the present invention, the allowable flatness of the surface of the barrier layer is preferably within the average thickness ±1.5 mm. When the allowable flatness of the surface of the barrier layer is within the above range, the barrier layer is less likely to wear away, and therefore the surface shape of the barrier layer does not have to conform to the irregularities of the object to be protected, making it possible to protect the substrate.

[0028] In the exhaust structure of the present invention, the pipe internal part is preferably a heater constituted by a metal honeycomb structure. When the inner pipe component is a heater made of a metal honeycomb structure, the heater can heat the exhaust gas flowing through the exhaust pipe. Therefore, even when the temperature of the exhaust gas is not sufficiently high, such as immediately after the engine is started, the exhaust gas can be heated to activate the catalytic action and suppress a decrease in the exhaust gas purification efficiency.

[0029] In the exhaust structure of the present invention, the barrier layer preferably has an average thickness of 0.1 mm to 3 mm. When the average thickness of the barrier layer is within the above range, wear of the gasket can be sufficiently suppressed.

[0030] In the exhaust structure of the present invention, it is preferable that the barrier layer is disposed on the entire surface of the base material of at least one of the two gaskets that faces the pipe inner component. When a barrier layer is disposed on the entire surface of the base material of at least one of the two gaskets that faces the internal pipe component, wear of the gasket can be particularly suppressed. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a perspective view diagrammatically illustrating an example of a gasket of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Diagram 3] FIG. 3 is a perspective view diagrammatically illustrating another example of the gasket of the present invention. [Figure 4] FIG. 4 is a cross-sectional view taken along line BB in FIG. [Diagram 5] FIG. 5 is a perspective view that illustrates a schematic view of still another example of the gasket of the present invention. [Figure 6] FIG. 6 is a cross-sectional view taken along line CC in FIG. [Figure 7] FIG. 7 is a perspective view that typically shows a substrate and a barrier layer that constitute still another example of the gasket of the present invention. [Figure 8] FIG. 8 is a top view of a gasket including the substrate and barrier layer shown in FIG. [Figure 9] FIG. 9 is a top view that illustrates an example of a process for producing a ring-shaped base material. [Figure 10] FIG. 10 is a perspective view that illustrates an example of cutting work for forming grooves in a ring-shaped base material. [Figure 11] FIG. 11 is a cross-sectional view that illustrates an example of the exhaust structure of the present invention. [Figure 12] FIG. 12 is a partially enlarged view of FIG. [Figure 13] FIG. 13 is a cross-sectional view that illustrates a schematic diagram of another example of the exhaust structure of the present invention. [Figure 14] FIG. 14 is a partially enlarged view of FIG. [Figure 15] FIG. 15 is a cross-sectional view that illustrates a schematic diagram of still another example of the exhaust structure of the present invention. [Figure 16] FIG. 16 is a partially enlarged view of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Hereinafter, the embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be appropriately modified and applied within the scope of the present invention.

[0033] [gasket] The gasket of the present invention is characterized by comprising a ring-shaped substrate composed of one or more members made of inorganic fibers, and a barrier layer containing a heat-resistant material disposed on at least a portion of the surface of the substrate.

[0034] FIG. 1 is a perspective view diagrammatically illustrating an example of a gasket of the present invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. The gasket 1 shown in FIG. 1 comprises a ring-shaped substrate 20 and a barrier layer 40 . The substrate 20 is composed of an integral member 10 made of inorganic fibers. Therefore, the substrate 20 is also the member 10 itself.

[0035] The substrate 20 has a first main surface 20a and a second main surface 20b that face each other in the thickness direction. A ring-shaped barrier layer 40 is disposed on a portion of the first main surface 20a of the substrate 20.

[0036] The shape of the substrate 20 is such that the inner diameter is R 21 , outer diameter is R 22 and the width is W 20 It is ring-shaped. The shape of the barrier layer 40 is such that the inner diameter is R 41 , outer diameter is R 42 and the width is W 40 It is ring-shaped.

[0037] Inner diameter R of the substrate 20 21 and the inner radius R of the barrier layer 40 41 is equal, but the outer diameter R 22 is the outer diameter R of the barrier layer 40 42 is larger than the width W of the substrate 20 20 is the width W of the barrier layer 40 40 Greater than. Therefore, when the gasket 1 is viewed from the first main surface 20a side of the substrate 20, the barrier layer 40 is disposed on a portion of the first main surface 20a, and a portion of the first main surface 20a appears to protrude outside the barrier layer 40.

[0038] The width of the ring-shaped substrate is also called the ring width. The same is true for the barrier layer, and the width of the ring-shaped barrier layer is also called the ring width.

[0039] FIG. 3 is a perspective view diagrammatically illustrating another example of the gasket of the present invention. FIG. 4 is a cross-sectional view taken along line BB in FIG. The gasket 2 shown in FIG. 3 is composed of a ring-shaped substrate 20 and a barrier layer 41. 1 and 2, the shape of the barrier layer 40 is changed. That is, the base material constituting the gasket 2 is the same as the base material constituting the gasket 1.

[0040] As shown in FIG. 4, the barrier layer 41 has an inner diameter R 43 , outer diameter is R 44 and the width is W 41 It is ring-shaped. Inner diameter R of the substrate 20 21 and the inner diameter R of the barrier layer 41 43 is equal, and the outer diameter R of the substrate 20 22 and the outer diameter R of the barrier layer 41 44 The ring width W of the substrate 20 is equal to 20 and the ring width W of the barrier layer 41 41 are equal. Therefore, when the gasket 2 is viewed from the first main surface 20a side, the barrier layer 41 is disposed over the entire first main surface 20a, and the substrate 20 and the barrier layer 41 completely overlap each other.

[0041] In the gasket of the present invention, grooves or the like may be formed on the surface of the substrate. An example in which a ring-shaped groove is formed on the surface of the substrate is shown below.

[0042] FIG. 5 is a perspective view that illustrates a schematic view of still another example of the gasket of the present invention. FIG. 6 is a cross-sectional view taken along line CC in FIG. The gasket 3 shown in FIG. 5 is made up of a ring-shaped substrate 22 and a barrier layer . The substrate 22 is composed of an integral member 12 made of inorganic fibers. Therefore, the substrate 22 is also the member 12 itself.

[0043] The base material 22 has a ring-shaped groove 50 on its inner periphery. On the outer periphery of the groove 50, an edge portion 30, which is a part of the base material 22, is disposed.

[0044] 6, the base material 22 has a first main surface 22a and a second main surface 22b that face each other in the thickness direction. A groove 50 is provided on the first main surface 22a side of the base material 22. The groove 50 opens into the first main surface 22a of the substrate 22 and the inner circumferential wall of the ring, and is defined by a groove bottom surface 22c parallel to the first main surface 22a and the second main surface 22b, and a groove side surface 22d parallel to the inner circumferential wall.

[0045] The barrier layer 42 is disposed on the bottom surface of the groove 50, that is, the groove bottom surface 22c. The thickness t of the barrier layer 42 42 is the depth d of groove 50 50 Less than. Therefore, when the substrate 22 is viewed from the side as in Figure 6, the barrier layer 42 is arranged so as to be embedded inside the groove 50, and does not protrude above (towards) the surface of the first main surface 22a.

[0046] The substrate 22 has an inner diameter R 23 , outer diameter R 24 , width W 22 It is ring-shaped. The groove 50 has an inner diameter R 45 , outer diameter R 46 , width W 50 It is ring-shaped. The edge portion 30 has an inner diameter R 25 , outer diameter R 24 , width W 30 It is ring-shaped. Groove 50 width W 50 and the width W of the edge 30 30 The sum of these is the width W of the substrate 22. 22 is equal to.

[0047] Inner diameter R of groove 50 45 is the inner diameter R of the substrate 22 23 and the outer diameter R of the substrate 22 is equal to 24 is the outer diameter R of groove 50 46 Greater than. That is, the grooves 50 are provided at positions that open into the inner peripheral wall of the base material 22, but do not open into the outer peripheral wall of the base material 22.

[0048] The barrier layer 42 has an inner diameter R 45 , outer diameter R 46 , width W 42 It is ring-shaped. Inner diameter R of groove 50 45 , outer diameter R 46 and ring width W 50 are the inner diameter R of the barrier layer 42. 45 , outer diameter R 46 and ring width W 42 Therefore, when viewed from the first main surface side, the barrier layer 42 exactly overlaps the groove 50, and it can be said that the barrier layer 42 is disposed over the entire groove bottom surface 22c. However, the barrier layer may be disposed only on a portion of the bottom surface of the groove.

[0049] Depth d of groove 50 50 is the thickness t of the barrier layer 42 in the thickness direction 42 It is preferable that it is greater than .

[0050] The groove 50 formed in the substrate 22 shown in Figures 5 and 6 is for disposing the barrier layer 42, but the substrate constituting the gasket of the present invention may be provided with another groove in addition to the groove for disposing the barrier layer described above. For example, the surface of the substrate may be provided with grooves or holes for passing electrical wiring therethrough. The object held by the gasket of the present invention may require electrical wiring to supply power from the outside. In such a case, if a groove or hole is provided on the surface of the base material for passing the electrical wiring, the electrical wiring can be passed through the groove or hole, and therefore the electrical wiring is less likely to be damaged.

[0051] In the gasket of the present invention, the substrate may be composed of a single member, or may be composed of a plurality of members. An example in which the base material is composed of a plurality of members will be described below.

[0052] FIG. 7 is a perspective view that typically shows a substrate and a barrier layer that constitute still another example of the gasket of the present invention. The gasket of the present invention is composed of, for example, a ring-shaped substrate 23 and a ring-shaped barrier layer 43 as shown in FIG.

[0053] The base material 23 is composed of a plurality of members (first member 13a, second member 13b) made of inorganic fibers. The first member 13a and the second member 13b are each non-ring-shaped when used alone, but are combined with each other to form a ring shape as a whole. Specifically, the first member 13a and the second member 13b each have an arc shape obtained by dividing the ring-shaped base material 23 into two equal parts in the circumferential direction.

[0054] The base material 23 has joints J1 and J2 between the first member 13a and the second member 13b.

[0055] The base material 23 has a first main surface 23a and a second main surface 23b that face each other in the thickness direction.

[0056] The barrier layer 43 is composed of a plurality of members (a first member 43a and a second member 43b). The first member 43a and the second member 43b constituting the barrier layer 43 each have a non-ring shape by itself, but are combined to form a ring shape as a whole. Specifically, the first member 43a and the second member 43b each have an arc shape obtained by dividing the ring-shaped barrier layer 43 into two equal parts in the circumferential direction.

[0057] The barrier layer 43 has seams J3 and J4 between the first member 43a and the second member 43b.

[0058] FIG. 8 is a top view of a gasket including the substrate and barrier layer shown in FIG. As shown in FIG. 8, the gasket 3 includes the substrate 23 and the barrier layer 43 shown in FIG. When the gasket 3 is viewed in the thickness direction, the seams J1 and J2 between the members that constitute the base material 23 do not overlap with the seams J3 and J4 between the members that constitute the barrier layer 43.

[0059] Although the cases where each member constituting the base material is non-ring-shaped have been described with reference to Figs. 7 and 8, each member constituting the base material may be ring-shaped. Similarly, when the barrier layer is made of a plurality of members and has a ring shape as a whole, each of the plurality of members constituting the barrier layer may be ring-shaped.

[0060] When each member constituting the substrate or barrier layer is ring-shaped, the shape of each member may be, for example, a substrate or barrier layer composed of a ring-shaped member having a relatively small diameter and a ring-shaped member having a relatively large diameter. In this case, it is preferable that the outer diameter of the ring-shaped member having a relatively small diameter is approximately the same as the inner diameter of the ring-shaped member having a relatively large diameter. By combining two members having such a shape, a ring-shaped substrate or barrier layer composed of two ring-shaped members can be obtained.

[0061] Next, the base material constituting the gasket of the present invention will be described. The base material constituting the gasket of the present invention is made of inorganic fibers.

[0062] Examples of the inorganic fibers constituting the substrate include silica fibers, alumina fibers, alumina-silica fibers, and biosoluble fibers.

[0063] The substrate preferably contains at least one type of inorganic fiber selected from the group consisting of silica fibers, alumina fibers, alumina-silica fibers, and biosoluble fibers.

[0064] The average fiber length of the inorganic fibers is preferably 0.5 to 100 mm. When the average fiber length of the inorganic fibers is 0.5 to 100 mm, the strength of the base material is increased, and the components can be stably held inside the exhaust pipe. If the average fiber length of the inorganic fibers is less than 0.5 mm, the fiber length is too short, and the inorganic fibers may not be sufficiently entangled with each other, resulting in a decrease in the strength of the substrate. Furthermore, when the average fiber length of the inorganic fibers exceeds 100 mm, the fiber length of the inorganic fibers is too long, and the handleability of the substrate may decrease.

[0065] The average fiber diameter of the inorganic fibers is preferably from 3 to 10 μm, and more preferably from 5 to 7 μm. When the average fiber diameter of the inorganic fibers is 3 to 10 μm, the strength and flexibility of the inorganic fibers are sufficiently high, and the shear strength of the substrate can be improved. If the average fiber diameter of the inorganic fibers is less than 3 μm, the inorganic fibers are thin and easily broken, resulting in insufficient tensile strength, whereas if the average fiber diameter of the inorganic fibers is more than 10 μm, the inorganic fibers are difficult to bend, resulting in insufficient flexibility of the substrate.

[0066] The silica fiber may contain additives other than silica, such as CaO, MgO, ZrO2, and the like.

[0067] The alumina fibers may contain additives other than alumina, such as CaO, MgO, ZrO2, and the like.

[0068] The composition ratio of the alumina-silica fibers is preferably Al2O3:SiO2=60:40 to 80:20 by weight, and more preferably Al2O3:SiO2=70:30 to 74:26. This is because such a composition ratio makes it easy to form mullite crystals, and the formation of mullite crystals improves the heat resistance and fiber strength.

[0069] Biosoluble fibers are made from alkali metal compounds, alkaline earth metal compounds, and boron compounds. The inorganic fibers are made of at least one compound selected from the group consisting of:

[0070] Since biosoluble fibers are easily dissolved when taken into the human body, the holding and sealing material including the inorganic fiber sheet formed by intertwining biosoluble fibers is excellent in safety for the human body. The above-mentioned alkali metal compounds include, for example, oxides of Na and K, and the above-mentioned alkaline earth metal compounds include, for example, oxides of Mg, Ca, and Ba. The above-mentioned boron compounds include, for example, oxides of B.

[0071] A specific composition of the biosoluble fiber includes 60 to 85% by weight of silica, and 15 to 40% by weight of at least one compound selected from the group consisting of alkali metal compounds, alkaline earth metal compounds, and boron compounds. The above-mentioned silica refers to SiO or SiO2. Examples of the alkali metal compounds include oxides of Na and K, and examples of the alkaline earth metal compounds include oxides of Mg, Ca, and Ba. Examples of the boron compounds include oxides of B.

[0072] In the composition of the biosoluble fiber, if the silica content is less than 60% by weight, it is difficult to prepare the fiber by the glass melting method and is difficult to form into fiber. Furthermore, if the silica content is less than 60% by weight, the structure will be fragile due to the low content of flexible silica, and the proportion of at least one compound selected from the group consisting of alkali metal compounds, alkaline earth metal compounds, and boron compounds, which are easily soluble in saline, will be relatively high, so the biosoluble fiber will tend to be too easily soluble in saline. On the other hand, if the silica content exceeds 85% by weight, the proportion of at least one compound selected from the group consisting of alkali metal compounds, alkaline earth metal compounds, and boron compounds becomes relatively low, and the biosoluble fiber tends to become too difficult to dissolve in saline. The silica content was calculated by converting the amounts of SiO and SiO2 into SiO2.

[0073] In addition, the content of at least one compound selected from the group consisting of alkali metal compounds, alkaline earth metal compounds, and boron compounds in the composition of the biosoluble fiber is desirably 15 to 40% by weight. If the content of at least one compound selected from the group consisting of alkali metal compounds, alkaline earth metal compounds, and boron compounds is less than 15% by weight, the biosoluble fiber tends to be too difficult to dissolve in physiological saline. On the other hand, if the content of at least one compound selected from the group consisting of alkali metal compounds, alkaline earth metal compounds, and boron compounds exceeds 40% by weight, it is difficult to prepare by the glass melting method and difficult to form fibers. Also, if the content of at least one compound selected from the group consisting of alkali metal compounds, alkaline earth metal compounds, and boron compounds exceeds 40% by weight, the structure becomes fragile, and the biosoluble fibers tend to dissolve too easily in physiological saline.

[0074] (I) First, 2.5 g of inorganic fibers are suspended in distilled water using a food blender, and then the suspension is left to settle to allow the inorganic fibers to settle. The supernatant liquid is then removed by decantation, and the suspension is dried at 110°C to remove the remaining liquid, thereby preparing an inorganic fiber sample.

[0075] (II) 6.780 g of sodium chloride, 0.540 g of ammonium chloride, 2.270 g of sodium bicarbonate, 0.170 g of disodium hydrogen phosphate, 0.060 g of sodium citrate dihydrate, 0.450 g of glycine, and 0.050 g of sulfuric acid (specific gravity 1.84) were distilled. Dilute to 1 liter (l) with water to prepare a saline solution.

[0076] (III) 0.50 g of the inorganic fiber sample prepared in (I) and 25 cm3 of the saline solution prepared in (II) are placed in a centrifuge tube, shaken well, and then treated in a shaking incubator at 37°C and 20 cycles / min for 5 hours. Thereafter, the centrifuge tube is removed, centrifuged at 4,500 rpm for 5 minutes, and the supernatant is removed with a syringe.

[0077] (IV) Next, the above supernatant is filtered through a filter (0.45 μm cellulose nitrate membrane filter), and the solubilities of silica, calcium oxide, and magnesium oxide in a physiological saline solution are measured for the obtained sample by atomic absorption spectrometry.

[0078] The substrate is preferably an aggregate of the above-mentioned inorganic fibers. The aggregate form of the inorganic fibers is not particularly limited, but may be, for example, in the form of a nonwoven fabric.

[0079] The base material may contain, for example, an organic binder as a component other than the inorganic fibers.

[0080] The thickness of the substrate is not particularly limited, but is preferably, for example, 1 to 50 mm. If the thickness of the substrate is less than 1 mm, the substrate is too thin and it may be difficult to hold the internal components inside the exhaust pipe without damaging them. Also, impacts applied to the exhaust pipe may be easily transmitted to the barrier layer, which may damage the barrier layer. It is more preferable to set the thickness of the substrate to be smaller than the width of the ring, so that the substrate is less likely to tilt or twist when the gasket is installed inside the exhaust pipe, making it easier to obtain the desired repulsive force.

[0081] The substrate can be obtained, for example, by forming a slurry containing inorganic fibers by a papermaking method, pressurizing and drying the resulting papermaking mat, and machining the same. When the base material is a paper mat produced by molding a slurry containing inorganic fibers by a papermaking method and drying it under pressure, the residual surface pressure of the paper mat is high, so that the residual surface pressure of the base material can be increased.

[0082] (1) Manufacturing method of papermaking mat by papermaking method (1-1) Mixed liquid preparation process An organic binder such as an acrylic resin and an inorganic binder are dissolved in water to prepare a binder solution. Next, the inorganic fibers, the binder solution, and water are mixed and stirred with a stirrer to prepare a mixed liquid. If necessary, a dispersant, a flocculant, etc. may be added to the mixed liquid. Alternatively, inorganic fibers may be crushed by a pulper to form short fibers, thereby obtaining a solution containing defibrated inorganic fibers.

[0083] (1-2) Dehydration process Next, the mixture is poured into a forming device having a filtering mesh formed on the bottom surface, and the water in the mixture is removed through the mesh to produce a raw material sheet.

[0084] (1-3) Pressure drying process Next, the raw material sheet is pressurized and dried to produce a paper mat. When drying, the drying temperature is preferably 100 to 250°C. The raw material sheet can be pressed using a press or the like. The pressure of the press is determined so that the bulk density of the resulting mat is a predetermined value. For example, the target bulk density of the mat after press drying is 0.161 g / cm3 When the pressure is applied, the bulk density is 0.214 g / cm 3 When the pressure is released, the raw mat expands due to the repulsive force of the fibers, so the bulk density decreases (thickness increases), and as a result, the target bulk density (0.161 g / cm 3 A paper mat of about 100% fineness can be obtained. Alternatively, drying may be performed simultaneously with pressing by using the press plate of the press machine as a hot plate and setting the temperature of the hot plate to a high temperature (for example, 100 to 250° C.). In this case, it is not necessary to set the temperature inside the system high during pressing, and the pressurized drying step can be performed by the heated press.

[0085] By carrying out the pressure drying step, the residual surface pressure of the paper-made mat can be increased, and a paper-made mat suitable for use as a base material for the gasket of the present invention can be obtained.

[0086] Through the above steps, a paper mat can be manufactured. In the above method, the binder solution is added to the mixture in the mixture preparation step. However, instead of using a binder solution in the mixture preparation step (1-1), the binder solution may be applied to the paper mat after the pressure drying step (1-3) and then dried, so that the acrylic resin and the inorganic binder containing water of crystallization are applied to the inorganic fibers of the paper mat.

[0087] The mat is then machined into a ring shape to produce a substrate. FIG. 9 is a top view that illustrates an example of a process for producing a ring-shaped base material. Fig. 9 shows a flat sheet-shaped paper mat 60. A ring-shaped punching blade is used to punch out the flat sheet-shaped paper mat 60 at the position shown by the ring-shaped line in Fig. 9, to obtain a ring-shaped paper mat 70.

[0088] As the ring-shaped punching blade, for example, a Thomson blade or the like can be used. Furthermore, punching is an example of mechanical processing, and the mechanical processing method is not limited to punching, and may be cutting, as long as the mechanical processing method can process the papermaking mat into a ring shape. The cutting process can be carried out using a machine tool such as milling or end milling.

[0089] Furthermore, the shape of the substrate punched out from the papermaking mat is not limited to a ring shape. For example, a ring-shaped substrate may be formed by punching out a non-ring-shaped component from a papermaking mat, which is not ring-shaped when combined with two or more components, and combining the resulting components.

[0090] The number of members constituting the substrate is preferably six or less. If the number of components exceeds six, the work of combining multiple components into one ring-shaped substrate can become complicated, and the number of seams between components increases, making it easier for exhaust gas to leak out.

[0091] The members constituting the substrate may have different shapes, but it is preferable that they all have the same shape. Furthermore, the shape of the member constituting the substrate may be either non-ring-shaped or ring-shaped.

[0092] When the two or more components constituting the substrate are not ring-shaped, the shape of each component may be, for example, an arc shape obtained by dividing a ring-shaped substrate so that the circumferential lengths of the ring are equal.

[0093] When the two or more members constituting the substrate are all ring-shaped, the substrate may be a combination of a ring-shaped member having a relatively large diameter and a ring-shaped member having a relatively small diameter. In this case, it is preferable that the inner diameter of the ring-shaped member having a relatively large diameter is approximately equal to the outer diameter of the ring-shaped member having a relatively small diameter.

[0094] In the ring-shaped paper mat obtained by the above procedure, a ring-shaped groove may be formed, if necessary. Fig. 10 is a perspective view showing an example of cutting to form grooves in a ring-shaped substrate. Fig. 10 shows a state in which cutting is performed on the inner periphery of a ring-shaped papermaking mat 70 using a cutting tool 80. The rotation of the cutting tool 80 is indicated by arrows around the cutting tool 80, and the direction in which the cutting tool 80 moves is indicated by an arrow pointing along the inner circumference of the ring-shaped papermaking mat 70. A groove 50 is formed in the ring-shaped paper mat 70 by cutting, and after the groove 50 is formed around the inner circumference of the ring-shaped paper mat 70, it becomes the base material 22 that constitutes the gasket 3 shown in Figures 5 and 6.

[0095] Next, the barrier layer constituting the gasket of the present invention will be described.

[0096] The barrier layer is disposed on at least a portion of a surface of the substrate. The position at which the barrier layer is disposed can be appropriately set in accordance with the shape of the substrate.

[0097] When the substrate has a first main surface and a second main surface opposed to each other in the thickness direction, it is preferable that a barrier layer is disposed on the first main surface. In a substrate having first and second main surfaces opposing each other in the thickness direction, when a barrier layer is disposed on the first main surface, wear of the gasket can be reliably suppressed by positioning the substrate so that the first main surface faces an inner pipe component and then using the gasket.

[0098] Furthermore, when the substrate has a first main surface and a second main surface opposing each other in the thickness direction, and further has a ring-shaped groove on the inner circumference of the ring, the groove opening into the first main surface and the inner wall of the ring, and defined by a groove bottom surface parallel to the first main surface and the second main surface, and a groove side surface parallel to the inner wall, it is preferable that a barrier layer is disposed on the groove bottom surface. By using a base material having a groove of the above shape, it is possible to hold an internal pipe part inside the groove. In this case, the bottom surface of the groove comes into contact with the internal pipe part, but since a barrier layer is disposed on the bottom surface of the groove, wear of the gasket can be reliably suppressed.

[0099] The barrier layer includes a heat resistant material. In this specification, a heat-resistant material refers to a material that has heat resistance at 900°C, which is the assumed exhaust gas temperature. In this specification, a material is considered to have heat resistance at 900°C if it experiences a weight loss rate of 5% or less when heated in air at 900°C for one hour.

[0100] Examples of the heat-resistant material include flaky inorganic materials and non-flaky inorganic materials. Examples of flaky inorganic materials include mica, vermiculite, montmorillonite, iron-montmorillonite, beidellite, saponite, hectorite, stevensite, nontronite, magadiite, ilealite, kanemite, smectite, and layered titanic acid.

[0101] The heat-resistant material is preferably at least one selected from the group consisting of alumina, zirconia, forsterite, steatite, cordierite, mullite, aluminum titanate, potassium titanate, mica, glass, and silica. Of these, mica is preferred.

[0102] The average thickness of the barrier layer is not particularly limited, but is preferably 0.005 mm to 5 mm, and more preferably 0.3 mm to 3 mm. When the average thickness of the barrier layer is within the above range, wear of the gasket can be sufficiently suppressed. The average thickness of the barrier layer is a value (average value) calculated by dividing the sum of the thicknesses of the barrier layer measured at five randomly selected points by the number of measurement points (5).

[0103] The bulk density of the barrier layer is not particularly limited, but is preferably 100 g / cm3 ~2000g / cm 3 It is preferable that:

[0104] The surface roughness Ra of the barrier layer is not particularly limited, but is preferably 0.2 μm to 25 μm, and more preferably 0.2 μm to 5 μm. When the surface roughness Ra of the barrier layer is within the above range, the barrier layer is less likely to wear away, and therefore the surface shape of the barrier layer does not need to conform to the irregularities of the object to be protected, making it possible to protect the substrate. The surface roughness Ra of the barrier layer surface is an arithmetic mean roughness measured in accordance with JIS B 0601:2001, and can be measured, for example, by HANDYSURF (manufactured by Tokyo Seimitsu Co., Ltd.).

[0105] Of the surfaces of the barrier layer, the surface roughness Ra of the surface facing the substrate is preferably the same as the surface roughness Ra of the surface not facing the substrate.

[0106] The allowable flatness of the barrier layer is preferably within the average thickness ±1.5 mm. The allowable flatness of the barrier layer refers to the allowable deviation of the maximum and minimum thicknesses of the barrier layer from the average thickness, i.e., the maximum thickness is allowed to be up to +1.5 mm from the average thickness, and the minimum thickness is allowed to be up to -1.5 mm from the average thickness. When the allowable flatness of the barrier layer is within the above range, the barrier layer is less likely to wear away, and therefore the surface shape of the barrier layer does not need to conform to the irregularities of the object to be protected, making it possible to protect the substrate.

[0107] The barrier layer can be obtained, for example, by impregnating a heat-resistant material with a silicone resin or the like as necessary, forming the material into a plate (sheet), and processing the plate into a ring shape.

[0108] In addition, natural minerals containing heat-resistant materials may be processed into a predetermined shape to form the barrier layer.

[0109] The shape of the barrier layer is not particularly limited, but it is preferable that the barrier layer has a ring shape as a whole. When the barrier layer has a ring shape, the inner diameter is preferably 20 mm to 205 mm, the outer diameter is preferably 45 mm to 230 mm, and the ring width is preferably 4 mm to 70 mm.

[0110] When the barrier layer has a ring shape, the ring width of the barrier layer is preferably 20 to 100% of the ring width of the substrate. It is also preferred that the inner diameter of the ring of the barrier layer is the same as the inner diameter of the ring of the substrate.

[0111] The barrier layer may be made up of multiple components.

[0112] The barrier layer may be adhered to the substrate. For example, an inorganic adhesive can be used to bond the barrier layer to the substrate.

[0113] Examples of inorganic adhesives include ceramic adhesives containing metal alkoxides, and ceramic adhesives containing alumina sol or silica sol.

[0114] The insulation resistance of the barrier layer is 10 8 Ωm~10 14 It is preferable that the volume resistivity decrease after heating at 550° C. for 1 hour is 1 / 500 or less of the volume resistivity before heating. When the insulation resistance of the barrier layer and the decrease in volume resistivity after heating at 550°C for 1 hour are within the above ranges, the barrier layer can ensure good insulation even when used in an exhaust pipe.

[0115] When the substrate and barrier layer constituting the gasket are both composed of multiple components, it is preferable that, when viewed in the thickness direction, the seams between the components constituting the substrate and the seams between the components constituting the barrier layer do not overlap. When viewed from the thickness direction, if the seams between the members constituting the base material and the seams between the members constituting the barrier layer do not overlap, it is possible to prevent exhaust gas from leaking through the seams.

[0116] [Exhaust structure] The exhaust structure of the present invention is an exhaust structure comprising an exhaust pipe, an internal pipe part to be placed inside the exhaust pipe, and a gasket that fixes the internal pipe part to the inside of the exhaust pipe, wherein the gasket is a ring-shaped gasket made of inorganic fiber, the internal pipe part is fixed to the inside of the exhaust pipe by being sandwiched between two of the gaskets, each of the two gaskets is composed of one or more members, the surface of the base material that faces the base material has an unevenness formed thereon, and a barrier layer containing a heat-resistant material is arranged on at least a portion of the surface of the base material that faces the internal pipe part.

[0117] FIG. 11 is a cross-sectional view that illustrates an example of the exhaust structure of the present invention. FIG. 12 is a partially enlarged view of FIG. The exhaust structure 200 shown in FIG. 11 includes an exhaust pipe 160, an internal pipe part 150 disposed in the exhaust pipe 160, and a first gasket 101 and a second gasket 102 that fix the internal pipe part 150 to the inside of the exhaust pipe 160. Exhaust gas discharged from an internal combustion engine flows into exhaust structure 200 (in FIG. 11, exhaust gas is indicated by G, and the flow of exhaust gas is indicated by arrows).

[0118] The inner pipe part 150 is prevented from shifting by being sandwiched between the two gaskets (the first gasket 101 and the second gasket 102), and the inner pipe part 150 is well held inside the exhaust structure 200. That is, the first gasket 101 and the second gasket 102 are used to hold the inner pipe part 150 inside the exhaust structure 200. Additionally, welding members 170 having an L-shaped cross section are provided adjacent to the first gasket 101 and the second gasket 102, respectively, and the welding members 170 are welded to the exhaust pipe 160 and fixed at a position sandwiching the first gasket 101 and the second gasket 102. Incidentally, the welded member 170 is also called a retaining ring because its outer shape is ring-shaped like the gasket that is the object to be retained.

[0119] Of the surfaces of the internal pipe part 150, the surfaces facing the first gasket 101 and the second gasket 102 are formed with projections and recesses. In Fig. 12, of the surfaces of the internal pipe part 150, the surfaces on which projections and recesses are formed are indicated by wavy lines.

[0120] The first gasket 101 includes a first substrate 121 and a barrier layer 141 . The first base material 121 constituting the first gasket 101 is a ring-shaped base material having a first main surface 121a and a second main surface 121b opposed to each other in the thickness direction (horizontal direction on the paper surface). Of the surfaces of the first base material 121, a barrier layer 141 is disposed on a first main surface 121a.

[0121] As shown in FIG. 12, the first main surface 121a of the first base material 121 is the surface facing the pipe internal part 150, and the second main surface 121b is the surface not facing the pipe internal part 150. The barrier layer 141 is disposed on the first main surface 121a of the first base material 121, thereby making it possible to prevent the surface of the internal pipe part 150 from directly contacting the first base material 121. Therefore, even if the surface of the internal pipe part 150 facing the first base material 121 has irregularities, it is possible to prevent the first base material 121 from being worn away by the irregularities.

[0122] The second gasket 102 includes a second substrate 122 and a barrier layer 142 . The second base material 122 constituting the second gasket 102 is a ring-shaped base material having a third main surface 122a and a fourth main surface 122b opposed to each other in the thickness direction (horizontal direction on the paper surface). A barrier layer 142 is disposed on a third main surface 122a of the second base material 122.

[0123] As shown in FIG. 12, the third main surface 122a of the second base material 122 is a surface that faces the pipe internal part 150, and the fourth main surface 122b is a surface that does not face the pipe internal part 150. Therefore, by disposing the barrier layer 142 on the third main surface 122a of the second base material 122, the surface of the pipe internal part 150 can be prevented from coming into direct contact with the second base material 122. Therefore, even if unevenness is formed on the surface of the pipe internal part 150 that faces the second base material 122, it is possible to prevent the second base material 122 from being worn away by the unevenness.

[0124] As shown in FIG. 12, it is preferable that neither the second main surface 121b of the first gasket 101 nor the fourth main surface 122b of the second gasket 102 faces the pipe inner part 150.

[0125] The pipe internal part 150 is, for example, a heater made of a metal honeycomb structure (hereinafter, also referred to as a metal honeycomb heater). The metallic honeycomb heater is a heating element that generates heat when electrically heated, and exhaust gas can pass through its interior. The temperature of the exhaust gas increases as the exhaust gas passes through the heated metallic honeycomb heater, and the high-temperature exhaust gas flows into the exhaust gas treatment body 180 located downstream. The exhaust gas treatment body 180 supports a catalyst for purifying the exhaust gas, and since the activity of the catalyst improves as the temperature of the exhaust gas treatment body 180 increases, it is preferable to increase the temperature of the exhaust gas treatment body 180. For the above reasons, a metallic honeycomb heater, which is an inner pipe component 150, is provided in the exhaust pipe in order to increase the temperature of the exhaust gas treatment body 180.

[0126] In the exhaust gas treatment body 180, exhaust gas flows in through cells that open on one end face, the exhaust gas is purified by a catalyst supported in the cells, and the purified exhaust gas flows out from the other end face. The exhaust gas treatment body may be made of a non-oxide porous ceramic such as silicon carbide or silicon nitride, or may be made of an oxide porous ceramic such as alumina, cordierite, or mullite.

[0127] As the catalyst supported on the exhaust gas treatment body 180, for example, noble metals such as platinum, palladium, rhodium, etc. are preferable, and among these, platinum is more preferable. In addition, as other catalysts, for example, alkali metals such as potassium and sodium, and alkaline earth metals such as barium, etc., can also be used. These catalysts may be used alone or in combination of two or more kinds. When these catalysts are supported, PM can be easily burned and removed, and toxic exhaust gas can also be purified.

[0128] The shape of the exhaust pipe is not particularly limited, but is, for example, substantially cylindrical. The material of the exhaust pipe is not particularly limited, but it is preferable that the exhaust pipe be made of stainless steel.

[0129] In the exhaust structure of the present invention, it is sufficient that a barrier layer is disposed on at least a portion of the surface of the base material constituting the gasket that faces the internal pipe component. However, it is preferable that a barrier layer is disposed on the entire surface of the base material constituting the gasket that faces the internal pipe component, as in exhaust structure 200 shown in Figures 11 and 12.

[0130] In the exhaust structure of the present invention, a barrier layer may be disposed only on the surface of the base material constituting one of the two gaskets sandwiching the internal pipe component that faces the internal pipe component, or a barrier layer may be disposed on the surface of the base material constituting the gasket that faces the internal pipe component for both of the two gaskets.

[0131] FIG. 13 is a cross-sectional view that illustrates a schematic diagram of another example of the exhaust structure of the present invention. FIG. 14 is a partially enlarged view of FIG. The exhaust structure 201 shown in FIG. 13 includes an exhaust pipe 160, an internal pipe part 150 disposed in the exhaust pipe 160, and a first gasket 103 and a second gasket 104 that fix the internal pipe part 150 to the inside of the exhaust pipe 160. Exhaust gas discharged from an internal combustion engine flows into exhaust structure 201 (in FIG. 13, exhaust gas is indicated by G, and the flow of exhaust gas is indicated by arrows).

[0132] The inner pipe part 150 is prevented from shifting by being sandwiched between the two gaskets (the first gasket 103 and the second gasket 104), and the inner pipe part 150 is well held in the exhaust structure 201. That is, the first gasket 103 and the second gasket 104 are used to hold the inner pipe part 150 in the exhaust structure 201. Additionally, welding members 170 having an L-shaped cross section are provided adjacent to the first gasket 103 and the second gasket 104, respectively, and the welding members 170 are welded to the exhaust pipe 160 and fixed at a position sandwiching the first gasket 103 and the second gasket 104.

[0133] Of the surfaces of the internal pipe part 150, the surfaces facing the first gasket 103 and the second gasket 104 are formed with projections and recesses. In Fig. 14, of the surfaces of the internal pipe part 150, the surfaces on which projections and recesses are formed are indicated by wavy lines.

[0134] The first gasket 103 includes a first substrate 121 and a barrier layer 143 . The first base material 121 constituting the first gasket 103 is a ring-shaped base material having a first main surface 121a and a second main surface 121b opposed to each other in the thickness direction (horizontal direction on the paper surface). A barrier layer 143 is disposed on the entire first main surface 121a of the first base material 121.

[0135] As shown in FIG. 14, the first main surface 121a of the first base material 121 is the surface facing the pipe internal part 150, and the second main surface 121b is the surface not facing the pipe internal part 150. The barrier layer 143 is disposed on the entire first main surface 121a of the first base material 121, thereby reliably preventing the surface of the internal pipe part 150 from directly contacting the first base material 121. Therefore, even if the surface of the internal pipe part 150 facing the first base material 121 has irregularities, it is possible to prevent the first base material 121 from being worn away by the irregularities.

[0136] The second gasket 104 includes a second substrate 122 and a barrier layer 144 . The second base material 122 constituting the second gasket 104 is a ring-shaped base material having a third main surface 122a and a fourth main surface 122b opposed to each other in the thickness direction (horizontal direction on the paper surface). A barrier layer 144 is disposed on the entire third main surface 122a of the second base material 122.

[0137] As shown in FIG. 14, the third main surface 122a of the second base material 122 is a surface that faces the pipe internal part 150, and the fourth main surface 122b is a surface that does not face the pipe internal part 150. Therefore, by disposing the barrier layer 144 on the entire third main surface 122a of the second base material 122, it is possible to reliably prevent the surface of the pipe internal part 150 from directly contacting the second base material 122. Therefore, even if unevenness is formed on the surface of the pipe internal part 150 that faces the second base material 122, it is possible to prevent the second base material 122 from being worn away by the unevenness.

[0138] As shown in FIG. 14, it is preferable that neither the second main surface 121b of the first gasket 103 nor the fourth main surface 122b of the second gasket 104 faces the pipe inner part 150.

[0139] FIG. 15 is a cross-sectional view that illustrates a schematic diagram of still another example of the exhaust structure of the present invention. FIG. 16 is a partially enlarged view of FIG. The exhaust structure 202 shown in FIG. 15 includes an exhaust pipe 160, an internal pipe part 150 disposed in the exhaust pipe 160, and a first gasket 105 and a second gasket 106 that fix the internal pipe part 150 to the inside of the exhaust pipe 160. Exhaust gas discharged from an internal combustion engine flows into exhaust structure 202 (in FIG. 15, exhaust gas is indicated by G, and the flow of exhaust gas is indicated by arrows).

[0140] The inner pipe part 150 is prevented from shifting by being sandwiched between the two gaskets (the first gasket 105 and the second gasket 106), and the inner pipe part 150 is well held inside the exhaust structure 202. That is, the first gasket 105 and the second gasket 106 are used to hold the inner pipe part 150 inside the exhaust structure 202. Additionally, welding members 170 having an L-shaped cross section are provided adjacent to the first gasket 105 and the second gasket 106, respectively, and the welding members 170 are welded to the exhaust pipe 160 and fixed at a position sandwiching the first gasket 105 and the second gasket 106.

[0141] Of the surfaces of the internal pipe part 150, the surfaces facing the first gasket 105 and the second gasket 106 are formed with projections and recesses. In Fig. 16, of the surfaces of the internal pipe part 150, the surfaces on which projections and recesses are formed are indicated by wavy lines.

[0142] The first gasket 105 includes a first substrate 123 and a barrier layer 145 . The first base material 123 constituting the first gasket 105 is a ring-shaped base material having a first main surface 123a and a second main surface 123b opposed to each other in the thickness direction (horizontal direction on the paper surface). Furthermore, the first base material 123 has a ring-shaped groove on the first main surface 123a side.

[0143] The ring-shaped groove opens into the first main surface 123a of the first base material 123 and into the inner circumferential wall of the ring, and is defined by a first groove bottom surface 123c and a first groove side surface 123d. The first groove bottom surface 123c is a surface that is parallel to the first main surface 123a and the second main surface 123b and corresponds to the bottom surface of the groove. The first groove side surface 123d is a surface that is parallel to the inner circumferential wall of the ring and corresponds to the side surface of the groove.

[0144] A barrier layer 145 is disposed on the first groove bottom surface 123c of the surface of the first base material 123. The first groove bottom surface 123c of the first base material 123 is the surface that faces the inner pipe part 150. Therefore, by disposing the barrier layer 145 on the first groove bottom surface 123c of the first base material 123, it is possible to prevent the surface of the inner pipe part 150 from directly contacting the first base material 123. Therefore, even if unevenness is formed on the surface of the pipe internal part 150 that faces the first base material 123, it is possible to prevent the first base material 123 from being worn away by the unevenness.

[0145] The second gasket 106 includes a second substrate 124 and a barrier layer 146 . The second base material 124 constituting the second gasket 106 is a ring-shaped base material having a third main surface 124a and a fourth main surface 124b that face each other in the thickness direction (horizontal direction on the paper surface). Furthermore, the second base material 124 has a ring-shaped groove on the third main surface 124a side.

[0146] The ring-shaped groove opens into the third main surface 124a of the second base material 124 and into the inner circumferential wall of the ring, and is defined by a second groove bottom surface 124c and a second groove side surface 124d. The second groove bottom surface 124c is a surface that is parallel to the third main surface 124a and the fourth main surface 124b and corresponds to the bottom surface of the groove. The second groove side surface 124d is a surface that is parallel to the inner circumferential wall of the ring and corresponds to the side surface of the groove.

[0147] A barrier layer 146 is disposed on the surface of the second base material 124, on the second groove bottom surface 124c. The second groove bottom surface 124c of the second base material 124 is the surface facing the internal pipe part 150. Therefore, by disposing the barrier layer 146 on the second groove bottom surface 124c of the second base material 124, it is possible to prevent the surface of the internal pipe part 150 from directly contacting the second base material 124. Therefore, even if unevenness is formed on the surface of the internal pipe part 150 facing the second base material 124, it is possible to suppress abrasion of the second base material 124 due to the unevenness.

[0148] Furthermore, as shown in FIG. 16, the first groove side surface 123d of the first substrate 123 and the second groove side surface 124d of the second substrate 124 are arranged in the outer circumferential direction of the inner pipe part 150, thereby preventing the inner pipe part 150 from shifting in a planar direction perpendicular to the axial direction of the exhaust pipe.

[0149] In the exhaust structure of the present invention, the terms "first gasket" and "second gasket" are merely used to distinguish between the two gaskets for convenience. Therefore, the first gasket and the second gasket may be the same gasket.

[0150] The type of exhaust pipe constituting the exhaust structure of the present invention is not particularly limited, but for example, the exhaust pipe is preferably made of stainless steel or the like. The diameter of the exhaust pipe is not particularly limited, but is preferably, for example, 45 mm to 230 mm.

[0151] The outside of the exhaust pipe may be insulated with a heat insulating material, if necessary.

[0152] An example of an internal pipe component disposed inside an exhaust pipe is a heater made of a metal honeycomb structure (metal honeycomb heater).

[0153] The present specification describes the following inventions:

[0154] The present disclosure (1) relates to a ring-shaped substrate composed of one or more members made of inorganic fibers; and a barrier layer including a heat-resistant material disposed on at least a portion of a surface of the substrate.

[0155] The present disclosure (2) is the gasket according to the present disclosure (1), wherein the heat-resistant material is at least one selected from the group consisting of alumina, zirconia, forsterite, steatite, cordierite, mullite, aluminum titanate, potassium titanate, mica, glass, and silica.

[0156] The present disclosure (3) is the gasket according to the present disclosure (1) or (2), wherein the surface roughness Ra of the surface of the barrier layer is 0.2 μm to 25 μm.

[0157] The present disclosure (4) is a gasket in any combination with any of the present disclosures (1) to (3), in which the allowable flatness of the surface of the barrier layer is within the average thickness ±1.5 mm.

[0158] The present disclosure (5) is a gasket in any combination with any of the present disclosures (1) to (4), in which the average thickness of the barrier layer is 0.1 mm to 3 mm.

[0159] The present disclosure (6) provides a method for manufacturing a semiconductor device, comprising the steps of: The gasket is an arbitrary combination with any of the present disclosures (1) to (5), in which the barrier layer is disposed on the first main surface.

[0160] The present disclosure (7) is directed to a method for manufacturing a ring-shaped groove having a first main surface and a second main surface opposed to each other in a thickness direction, and a ring-shaped groove on an inner circumference of the ring, the groove opening into the first main surface and an inner circumferential wall of the ring, the groove bottom surface being parallel to the first main surface and the second main surface, and a groove side surface being parallel to the inner circumferential wall; The gasket is an arbitrary combination with any of the gaskets disclosed herein (1) to (5), in which the barrier layer is disposed on the bottom surface of the groove.

[0161] The present disclosure (8) provides a method for manufacturing a semiconductor device comprising the steps of: forming a substrate into a ring shape by combining a plurality of non-ring-shaped members; and having a first main surface and a second main surface opposed to each other in a thickness direction; The barrier layer is disposed on the first main surface and is formed into a ring shape by combining a plurality of non-ring-shaped members. The gasket is any combination of any of the gaskets disclosed herein (1) to (7), in which the seams between the components constituting the base material and the seams between the components constituting the barrier layer do not overlap when viewed in the thickness direction.

[0162] The present disclosure (9) provides an exhaust structure including an exhaust pipe, an internal pipe part disposed inside the exhaust pipe, and a gasket that fixes the internal pipe part to the inside of the exhaust pipe, The gasket comprises a ring-shaped base material made of inorganic fibers, and a barrier layer made of a heat-resistant material and disposed on at least a portion of a surface of the base material; The pipe internal part is fixed inside the exhaust pipe by being sandwiched between the two gaskets, The two base materials constituting the two gaskets are each composed of one unit or multiple members, The surface of the pipe internal component facing the base material is provided with projections and recesses, The exhaust structure is characterized in that the barrier layer is disposed on at least a portion of a surface of the base material that faces the pipe internal component.

[0163] The present disclosure (10) relates to a method for manufacturing a gas-sealed housing, the two gaskets being a first gasket and a second gasket, The first base material constituting the first gasket has a first main surface and a second main surface opposed to each other in a thickness direction, The second base material constituting the second gasket has a third main surface and a fourth main surface opposed to each other in a thickness direction, the first main surface and the third main surface are surfaces facing the pipe internal component, The exhaust structure according to the present disclosure (9), wherein the barrier layer is disposed on at least a portion of a surface of the first main surface and at least a portion of a surface of the third main surface.

[0164] The present disclosure (11) relates to a first gasket and a second gasket, a first base material constituting the first gasket has a first main surface and a second main surface opposed to each other in a thickness direction, and further has a ring-shaped groove on an inner circumference of a ring, the groove opening into the first main surface and an inner circumferential wall of the ring, the groove being defined by a first groove bottom surface parallel to the first main surface and the second main surface, and a first groove side surface parallel to the inner circumferential wall; a second base material constituting the second gasket has a third main surface and a fourth main surface opposed to each other in a thickness direction, and further has a ring-shaped groove on an inner circumference of the ring, the groove opening into the third main surface and an inner peripheral wall of the ring, the second groove bottom surface being parallel to the third main surface and the fourth main surface, and a second groove side surface being parallel to the inner peripheral wall; the first groove bottom surface and the second groove bottom surface are surfaces facing the pipe internal component, The exhaust structure according to the present disclosure (9), wherein the barrier layer is disposed on at least a portion of the first groove bottom surface and at least a portion of the second groove bottom surface.

[0165] The present disclosure (12) is the exhaust structure according to the present disclosure (10) or (11), in which neither the second main surface nor the fourth main surface faces the pipe inner component.

[0166] The present disclosure (13) is an exhaust structure in any combination with any of the present disclosures (9) to (12), wherein the heat-resistant material is at least one selected from the group consisting of alumina, zirconia, forsterite, steatite, cordierite, mullite, aluminum titanate, potassium titanate, mica, glass, and silica.

[0167] The present disclosure (14) is an exhaust structure in any combination with any of the present disclosures (9) to (13), in which the surface roughness Ra of the surface of the barrier layer is 0.2 μm to 25 μm.

[0168] The present disclosure (15) is an exhaust structure in any combination with any of the present disclosures (9) to (14), in which the allowable flatness of the surface of the barrier layer is within an average thickness of ±1.5 mm.

[0169] The present disclosure (16) is an exhaust structure in any combination with any of the present disclosures (9) to (15), in which the pipe internal part is a heater made of a metal honeycomb structure.

[0170] The present disclosure (17) is an exhaust structure in any combination with any of the present disclosures (9) to (16), in which the average thickness of the barrier layer is 0.1 mm to 3 mm.

[0171] The present disclosure (18) is an exhaust structure in any combination with any of the present disclosures (9) to (17), in which the barrier layer is disposed on the entire surface of the base material of at least one of the two gaskets that faces the pipe inner component.

[0172] [Example] EXAMPLES Hereinafter, examples that more specifically disclose the present invention will be described, however, the present invention is not limited to these examples.

[0173] Example 1 (1-1) Mixed liquid preparation process A basic aluminum chloride aqueous solution was prepared so that the Al content was 70 g / L and the atomic ratio of Al:Cl was 1:1.8. Silica sol was then added so that the composition ratio of the inorganic fibers after firing would be Al2O3:SiO2 = 72:28 (weight ratio). An appropriate amount of organic polymer (polyvinyl alcohol) was then added to prepare a mixed solution. The resulting mixture was concentrated to prepare a spinning mixture, which was then spun by a blowing method to prepare an inorganic fiber precursor. The inorganic fiber precursor was then compressed to prepare a rectangular sheet-like material. The compressed sheet-like material was fired at a maximum temperature of 1250°C to prepare inorganic fibers (average fiber diameter 5 μm) containing alumina and silica in a ratio of 72 parts by weight:28 parts by weight.

[0174] 10 kg of the above inorganic fibers were added to 1,500 L of water and stirred at 650 rpm for 20 minutes using a commercially available pulper (capacity approximately 2,000 L) to crush and shorten the inorganic fibers, thereby obtaining a solution of defibrated inorganic fibers.

[0175] A portion of the solution of the defibrated inorganic fibers was removed so that the fiber content was 170 g and the water was 75 L. 21.7 g of a commercially available acrylic latex solution (solid content 50% by weight) in which an acrylic resin was dispersed in water was added to this, and the mixture was stirred at 650 rpm for 1 minute to prepare a mixed liquid. The amount of the acrylic resin, which is an organic binder, attached was 7.0% by weight based on the paper mat.

[0176] (1-2) Dehydration process Next, the mixture was poured into a forming machine having a filtering mesh formed on the bottom surface, and the water in the mixture was removed through the mesh to produce a raw material sheet.

[0177] (1-3) Pressure drying process Next, the raw material sheet is compressed to a thickness of about 75% (bulk density when pressed: 0.214 g / cm 3 The pressure was adjusted so that the thickness of the film was increased to 100 mm. Through the above steps, a paper mat was produced. The bulk density of the paper mat is 0.161g / cm 3 It was.

[0178] (1-4) Machining process The papermaking mat was punched out using a ring-shaped punching blade to prepare a ring-shaped substrate. The obtained substrate had a ring shape with an inner diameter of 30 mm, an outer diameter of 50 mm, a width of 10 mm, and a thickness of 12 mm.

[0179] (2) Preparation of the Barrier Layer An insulating sheet (flexible mica insulating sheet, manufactured by Widework Co., Ltd.) with an average thickness of 0.3 mm was prepared, in which mica was integrated with an adhesive. This insulating sheet was punched into a ring shape with an inner diameter of 30 mm, an outer diameter of 50 mm, and a width of 10 mm, and then sintered at 900°C for 1 hour to prepare a barrier layer. The surface roughness Ra of the barrier layer was 3.7 μm on both sides. The maximum and minimum thicknesses of the obtained barrier layer were +0.04 mm and -0.04 mm, respectively, of the average thickness. The obtained barrier layer was arranged so as to overlap the first main surface of the ring-shaped base material, thereby obtaining a gasket according to Example 1. At this time, the barrier layer was arranged so that one surface of the barrier layer was in contact with the first main surface of the ring-shaped base material.

[0180] <Vibration test> A metal honeycomb heater having a diameter of 101 mm, a length of 28 mm, and a weight of 0.24 kg was sandwiched between two gaskets according to Example 1 at the front and rear in the longitudinal direction, and then sandwiched between metal plates at the front and rear. The bulk density (GBD) of the base material constituting the gasket was 0.5 g / cm 3 The specimen was compressed and fixed with a metal plate until the specimen reached a compressible state, thereby preparing a sample for vibration testing. At this time, the first main surface of the base material constituting the gasket was oriented to face the metal honeycomb heater, and the barrier layer was disposed between the base material constituting the gasket and the metal honeycomb heater. The metal honeycomb heater is made by pressing a stainless steel wire mesh material into an uneven shape and rolling it up, and the unevenness is formed at intervals of about 1 to 1.5 mm on the front and back surfaces in the length direction.

[0181] The vibration test sample was placed in a vibration test device and a vibration test was carried out. The weight changes of the substrate and the barrier layer before and after the vibration test were measured to determine the weight loss rates. The results are shown in Table 1. <Vibration test conditions> The conditions are as follows: Vibration acceleration: 60G Vibration frequency: 200Hz Vibration time: 30 min

[0182] Example 2 A gasket according to Example 2 was produced and subjected to a vibration test in the same manner as in Example 1, except that the barrier layer was changed to an insulating sheet (D581 manufactured by Okabe Mica Co., Ltd.) with an average thickness of 0.3 mm, in which laminated mica was integrated with a silicone adhesive. The results are shown in Table 1. The maximum and minimum thicknesses of the obtained barrier layer were +4 mm and -4 mm, respectively, of the average thickness.

[0183] Comparative Example 1 A ring-shaped substrate (paper mat) with no barrier layer disposed on the first main surface was used as a gasket according to Comparative Example 1, and a vibration test was carried out in the same manner as in Example 1. The results are shown in Table 1.

[0184] Comparative Example 2 Aside from changing the barrier layer to a sewn ceramic fiber product (3M, Nextel BF-30, average thickness 0.8 mm), a vibration test was carried out in the same manner as in Example 1. The results are shown in Table 1.

[0185] [Table 1]

[0186] From the results in Table 1, when the gaskets according to Examples 1 and 2 having a barrier layer were used, the weight loss rate of the base material could be suppressed to 1% or less compared to when the gasket according to Comparative Example 1 having no barrier layer was used. In addition, wear of the barrier layer itself could be prevented. When the gasket according to Comparative Example 2 was used, the weight loss rate of the base material could be suppressed, but it was found that wear of the barrier layer itself was likely to progress. From the above results, it was found that by using the gasket of the present invention, wear can be suppressed even when holding an internal pipe part having an uneven surface. [Explanation of symbols]

[0187] 1, 2, 3, 4 Gasket 10, 12 Parts 13a First member 13b Second member 20, 22, 23 Base material 20a, 22a, 23a: First main surface of substrate 20b, 22b, 23b Second main surface of substrate 22c Bottom surface of groove in substrate 22d Groove side of substrate 30 Edge 40, 41, 42, 43 Barrier layer 43a first member of barrier layer 43b second member of the barrier layer 50 grooves 60 Flat sheet mat 70 Ring-shaped paper mat 80 Cutting tools 101, 102, 103, 104, 105, 106 Gaskets 121, 123 1st base material 122, 124 Second base material 121a: First main surface of first substrate 121b: second main surface of the first substrate 122a: third main surface of second substrate 122b: fourth main surface of second substrate 123a: First main surface of first substrate 123b: second main surface of the first substrate 123c: First groove bottom surface of first substrate 123d: first groove side surface of first substrate 124a: third main surface of second substrate 124b: fourth main surface of the second substrate 124c: second groove bottom surface of second substrate 124d: second groove side surface of second substrate 141, 142, 143, 144, 145, 146 Barrier layer 150 Internal pipe parts 160 Exhaust pipe 170 Welding parts (retaining ring) 180 Catalyst Carrier 190 Retaining sealant 200, 201, 202 Exhaust structure R 21 , R 23 Inner diameter of substrate R 22 , R 24 Outer diameter of substrate R 41 , R 43 , R 45 Barrier layer inner diameter R 42 , R 44 , R 46 Barrier layer inner diameter R25 Groove Outer Diameter W 20 , W 22 Width of substrate (ring width) W 40 , W 41 , W 42 Barrier layer width (ring width) W 30 Edge width W 50 Groove Width t 42 Barrier Layer Thickness d 50 Groove depth Joints between components that make up the J1 and J2 base materials J3, J4 Joints between the components that make up the barrier layer

Claims

1. A ring-shaped substrate composed of one or more members made of inorganic fibers; a barrier layer disposed on at least a portion of a surface of the substrate, the barrier layer comprising a heat resistant material.

2. 2. The gasket according to claim 1, wherein the heat-resistant material is at least one selected from the group consisting of alumina, zirconia, forsterite, steatite, cordierite, mullite, aluminum titanate, potassium titanate, mica, glass, and silica.

3. 2. The gasket according to claim 1, wherein the surface roughness Ra of the surface of the barrier layer is 0.2 μm to 25 μm.

4. 2. The gasket of claim 1, wherein the barrier layer has a surface with an acceptable flatness within an average thickness of ±1.5 mm.

5. The gasket of claim 1 , wherein the barrier layer has an average thickness of 0.1 mm to 3 mm.

6. The substrate has a first main surface and a second main surface opposed to each other in a thickness direction, The gasket according to any one of claims 1 to 5, wherein the barrier layer is disposed on the first main surface.

7. The substrate has a first main surface and a second main surface opposed to each other in a thickness direction, and further has a ring-shaped groove on an inner circumference of the ring, the groove opening into the first main surface and an inner circumferential wall of the ring, and defined by a groove bottom surface parallel to the first main surface and the second main surface and a groove side surface parallel to the inner circumferential wall, The gasket according to any one of claims 1 to 5, wherein the barrier layer is disposed on the bottom surface of the groove.

8. The base material is formed into a ring shape by combining a plurality of non-ring-shaped members, and has a first main surface and a second main surface opposed to each other in a thickness direction, the barrier layer is disposed on the first main surface, and is formed into a ring shape by combining a plurality of non-ring-shaped members; 6. The gasket according to claim 1, wherein, when viewed in the thickness direction, seams between members constituting the base material and seams between members constituting the barrier layer do not overlap.

9. An exhaust structure comprising an exhaust pipe, an internal pipe component disposed inside the exhaust pipe, and a gasket that fixes the internal pipe component to the inside of the exhaust pipe, The gasket comprises a ring-shaped base material made of inorganic fibers, and a barrier layer made of a heat-resistant material and disposed on at least a portion of a surface of the base material; The pipe internal part is fixed inside the exhaust pipe by being sandwiched between the two gaskets, The two base materials constituting the two gaskets are each composed of one or more members, The surface of the pipe internal component facing the base material is provided with projections and recesses, an exhaust structure, characterized in that the barrier layer is disposed on at least a portion of a surface of the base material that faces the pipe internal component.

10. The two gaskets are a first gasket and a second gasket, The first base material constituting the first gasket has a first main surface and a second main surface opposed to each other in a thickness direction, The second base material constituting the second gasket has a third main surface and a fourth main surface opposed to each other in a thickness direction, the first main surface and the third main surface are surfaces facing the pipe internal component, The exhaust structure according to claim 9 , wherein the barrier layer is disposed on at least a portion of a surface of the first main surface and at least a portion of a surface of the third main surface.

11. The two gaskets are a first gasket and a second gasket, a first base material constituting the first gasket has a first main surface and a second main surface opposed to each other in a thickness direction, and further has a ring-shaped groove on an inner circumference of a ring, the groove opening into the first main surface and an inner circumferential wall of the ring, the groove being defined by a first groove bottom surface parallel to the first main surface and the second main surface, and a first groove side surface parallel to the inner circumferential wall; a second base material constituting the second gasket has a third main surface and a fourth main surface opposed to each other in a thickness direction, and further has a ring-shaped groove on an inner circumference of the ring, the groove opening into the third main surface and an inner circumferential wall of the ring, and defined by a second groove bottom surface parallel to the third main surface and the fourth main surface and a second groove side surface parallel to the inner circumferential wall; the first groove bottom surface and the second groove bottom surface are surfaces facing the pipe internal component, The exhaust structure according to claim 9 , wherein the barrier layer is disposed on at least a portion of the first groove bottom surface and at least a portion of the second groove bottom surface.

12. The exhaust structure according to claim 10 or 11, wherein neither the second main surface nor the fourth main surface faces the pipe inner component.

13. The exhaust structure according to any one of claims 9 to 11, wherein the heat-resistant material is at least one selected from the group consisting of alumina, zirconia, forsterite, steatite, cordierite, mullite, aluminum titanate, potassium titanate, mica, glass, and silica.

14. The exhaust structure according to any one of claims 9 to 11, wherein the surface roughness Ra of the surface of the barrier layer is 0.2 µm to 25 µm.

15. 12. The exhaust structure according to claim 9, wherein the allowable flatness of the surface of the barrier layer is within an average thickness of ±1.5 mm.

16. The exhaust structure according to any one of claims 9 to 11, wherein the pipe internal part is a heater made of a metal honeycomb structure.

17. The exhaust structure according to any one of claims 9 to 11, wherein the barrier layer has an average thickness of 0.1 mm to 3 mm.

18. The exhaust structure according to any one of claims 9 to 11, wherein the barrier layer is disposed on an entire surface of the base material of at least one of the two gaskets that faces the pipe inner component.

Images