JP5999980B2 - Mounting system and contamination control device - Google Patents

Description

  One aspect of the present invention relates to a mounting system for mounting a pollution control element inside a pollution control device and the pollution control device.

  Conventionally, catalytic converters are known as means for removing carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), etc. contained in the exhaust gas of a car engine from the exhaust gas. . For example, in Patent Document 1 below, a monolith that is formed in a cylindrical shape and carries an exhaust gas purification catalyst, a metal casing that contains the monolith and is connected to an exhaust gas conduit, and a monolith wound around the monolith. A catalytic converter composed of a monolith holding material interposed in a gap between the monolith and a casing is described.

Japanese Patent No. 3072281

  A pollution control element such as a monolith catalyst is firmly fixed by being mounted in a casing of a pollution control device (for example, a catalytic converter) while being wound around a mat-like mounting system such as the above-mentioned monolith holding material. The Therefore, the mounting system needs to have sufficient pressure in its casing to hold down the pollution control element.

  However, wrapping the mounting system around the pollution control element causes wrinkles on the inner surface of the system. Then, when the contamination control element is to be installed in the casing and after the installation, an unnecessarily high pressure is generated around the wrinkle, which may damage the contamination control element.

  Therefore, it is required to stably fix the element to the pollution control device without damaging the pollution control element.

  An attachment system according to an aspect of the present invention is an attachment system for attaching a pollution control element to an inside of a pollution control device, and includes a first sheet layer and a first sheet layer when the pollution control element is attached. A groove pattern is formed on the surface of the second sheet layer that is in contact with the contamination control element at the time of attachment, and the hardness of the first sheet layer is that of the second sheet layer. N times the hardness, where n is greater than 1 and 3 or less.

  According to such a form, the hardness of the first sheet layer located outside when the contamination control element is attached is n times the hardness of the second sheet layer located inside when the pollution control element is attached (where 1 <n ≦ 3). By setting the hardness of the two sheet layers in this manner, the contamination control element can be fixed in the apparatus with a stable and appropriate pressure when the contamination control element is attached to the contamination control apparatus and after the attachment. it can. In addition, by forming a groove pattern on the surface of the second sheet layer that contacts the contamination control element, the mounting system can be wrapped around the element without causing uneven wrinkles on the inner surface of the mounting system. As a result, it is possible to suppress the occurrence of a portion where a higher pressure is applied than in the vicinity and prevent damage to the pollution control element.

  In the attachment system according to another aspect, the hardness of the first sheet layer may be 50 to 90, and the hardness of the second sheet layer may be 30 to 80.

  In a mounting system according to another embodiment, the density of the first sheet layer is n times the density of the second sheet layer, where n may be greater than 1 and 3 or less.

In a mounting system according to another embodiment, the density of the first sheet layer is 0.12 to 0.30 g / cm ³ and the density of the second sheet layer is 0.10 to 0.25 g / cm ³ . There may be.

  In a mounting system according to another embodiment, the thickness of the second sheet layer may be equal to or less than the thickness of the first sheet layer.

  In a mounting system according to another embodiment, the ratio between the thickness of the first sheet layer and the thickness of the second sheet layer may be 30: 1 to 1: 1.

  In a mounting system according to another embodiment, the thickness of the first sheet layer may be 3 to 15 mm, and the thickness of the second sheet layer may be 0.5 to 15 mm.

  In the mounting system according to another embodiment, the first sheet layer may be manufactured by a dry method, and the second sheet layer may be manufactured by a wet method.

  In the attachment system according to another embodiment, the groove pattern may include a plurality of grooves extending in a direction substantially orthogonal to the winding direction of the second sheet layer.

  In a mounting system according to another embodiment, the interval between two adjacent grooves may be 3 to 50 mm.

  A mounting system according to still another embodiment is a mounting system for mounting a pollution control element inside a pollution control device, the first sheet layer and an inner side of the first sheet layer when the pollution control element is mounted. A groove pattern is formed on the surface of the second sheet layer that is in contact with the contamination control element at the time of attachment, and the density of the first sheet layer is equal to the density of the second sheet layer. N, where n may be greater than 1 and 3 or less.

  A pollution control device according to an aspect of the present invention includes a casing, a pollution control element disposed in the casing, and any of the above-described mounting systems, and the mounting system performs pollution control at a desired position in the casing. Arranged between the casing and the pollution control element to hold an element.

  According to one aspect of the present invention, the element can be stably fixed to the pollution control device without damaging the pollution control element.

It is sectional drawing along the axial direction of the catalytic converter provided with the attachment system which concerns on embodiment. It is the II-II sectional view taken on the line of FIG. It is a figure which shows a mode that a pollution control element is pushed in a casing using the attachment system which concerns on embodiment. It is a perspective view of the attachment system concerning an embodiment. It is a figure for demonstrating the pressure measuring method in an Example. It is a graph which shows the pressure measurement result which concerns on an Example. It is a graph which shows the pressure measurement result which concerns on a comparative example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

  First, the structure of the attachment system 20 which concerns on embodiment, and the structure of the catalytic converter 10 provided with the attachment system 20 are demonstrated using FIGS.

  The catalytic converter 10 is a pollution control device that processes exhaust gas generated from an internal combustion engine such as a car engine. The type of vehicle on which the catalytic converter 10 is mounted is not limited. For example, the catalytic converter 10 can be mounted on various vehicles such as passenger cars, buses, and trucks. As shown in FIG. 1, the catalytic converter 10 is inserted in the middle of an exhaust pipe 32 connected to the internal combustion engine 31. The catalytic converter 10 includes a casing 11, a pollution control element 12 disposed in the casing 11, and a mounting system 20 disposed between the casing 11 and the pollution control element 12.

  As shown in FIG. 3, the catalytic converter 10 is formed by pressing and fixing the pollution control element 12 wound around the outer periphery of the mounting system 20 from the open end of the casing 11. At this time, the mounting system 20 fills the gap between the casing 11 and the contamination control element 12 under a predetermined compressive force. Then, the movement of the contamination control element 12 is hindered by the compression force or the surface friction force generated by the mounting system 20, and as a result, the contamination control element 12 is firmly fixed in the casing 11. Since the contamination control element 12 is held by the mounting system 20 as described above, basically, it is not necessary to use other joining means such as an adhesive or an adhesive sheet. Of course, other joining means may be used in combination with the mounting system 20.

  The casing 11 is a member that forms part of the exhaust pipe 32 and is also referred to as a housing. The casing 11 can be manufactured from various known metal materials. For example, the casing 11 may be manufactured from stainless steel, iron, aluminum, titanium, or an alloy thereof. As shown in FIGS. 1 and 2, the casing 11 is cylindrical in this embodiment, but the shape of the casing 11 may be arbitrarily determined. As shown in FIG. 1, an inlet 13 for receiving the exhaust gas flowing from the internal combustion engine 31 is attached to one end of the casing 11, and the exhaust gas purified by the pollution control element 12 is downstream in the other end. A delivery outlet 14 is attached. Both the inflow port 13 and the outflow port 14 have a substantially truncated cone shape.

  The pollution control element 12 is a component that removes at least a part of a specific component contained in the exhaust gas flowing from the inlet 13 and passes the purified exhaust gas to the outlet 14. The pollution control element 12 exhibits a useful catalytic action of removing carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx) and the like at a relatively high temperature. The pollution control element 12 is formed by supporting a catalyst on the catalyst carrier 12a.

  The catalyst carrier 12a is generally a monolith type carrier having a honeycomb structure having a plurality of exhaust gas passages. The catalyst carrier 12a can be manufactured from a known material, for example, from metal or ceramic. As shown in FIGS. 1 and 2, in this embodiment, the catalyst carrier 12a is cylindrical, but the shape of the catalyst carrier 12a may be arbitrarily determined in the same manner as the casing. Further, the catalyst carrier 12a is not limited to the monolith type.

  The catalyst supported on the catalyst support 12a is generally a metal (eg, platinum, ruthenium, osmium, rhodium, iridium, nickel, or palladium) or a metal oxide (eg, vanadium pentoxide or titanium dioxide). For example, the catalyst is coated on the catalyst support 12a. The catalyst coating is described in detail, for example, in US Pat. No. 3,441,381.

  The mounting system 20 is a mat-like member for fixing the pollution control element 12 in the casing 11. The method of fixing the contamination control element 12 using the mounting system 20 is as described with reference to FIG. In addition to this fixing function, the mounting system 20 also serves to prevent damage to the element 12 when the pollution control element 12 is pushed into the casing 11. In addition, the mounting system 20 also has a heat insulating function.

  What is necessary is just to set the dimension of the attachment system 20 according to a use purpose and the dimension of a pollution control apparatus. For example, the mounting system 20 used in a vehicle catalytic converter typically has a thickness of about 3.5 to 30 mm, a width of about 20 to about 500 mm, and a length of about 100 to about 1500 mm. The mounting system 20 can be cut into a desired shape and size using scissors, a cutter, or the like.

  As shown in FIG. 4, the attachment system 20 is formed by overlapping and joining two kinds of sheet-like layers (sheet layers). Specifically, the attachment system 20 includes a first sheet layer 21 located outside when wound around the pollution control element 12, and a second sheet layer 22 located inside in this case. The first sheet layer 21 and the second sheet layer 22 are substantially the same in material, but the manufacturing method is different. Due to the difference in the manufacturing method, the properties of these two types of sheet layers are different from each other.

  The materials of the first sheet layer 21 and the second sheet layer 22 will be described. Both of these two types of sheet layers are manufactured using a fiber material (for example, inorganic fiber). Examples of inorganic fibers used in the sheet layer include glass fibers, ceramic fibers (eg, alumina fibers, silica fibers, alumina-silica fibers), carbon fibers, silicon carbide fibers, and boron fibers, but other inorganic fibers. Fiber may be used. These inorganic fibers may be used alone or in combination of two or more.

  You may form a sheet | seat layer by adding another inorganic material to said various inorganic fiber. Examples of additives include zirconia, magnesia, calcia, chromium oxide, yttrium oxide, and lanthanum oxide, but are not limited to these examples. These additives can generally be used in the form of powder or fine particles, and can be used either alone or in combination of two or more.

As an example, an inorganic fiber containing alumina (Al ₂ O ₃ ) and silica (SiO ₂ ) used in a wet method will be described. The range of the mixing ratio of alumina and silica in this inorganic fiber is about 40:60 to about 96: 4. When the mixing ratio of alumina and silica is out of this range, for example, when the mixing ratio of alumina is less than 40%, the heat resistance of the sheet layer is lowered.

  Although the thickness (average diameter) of each inorganic fiber is not particularly limited, it is, for example, about 2 to 15 μm. If this average diameter is less than about 2 μm, the fiber may become brittle. On the other hand, if the average diameter exceeds about 15 μm, it may be difficult to form the sheet layer and the mounting system 20.

  The length of the inorganic fiber is not particularly limited, but is, for example, about 0.5 to 50 mm on average. If this average length is less than about 0.5 mm, it becomes difficult to form the sheet layer and the mounting system 20. On the other hand, when the average length exceeds about 50 mm, it becomes difficult to handle the fibers, and it becomes difficult to smoothly manufacture the mounting system 20.

On the other hand, as an example of the inorganic fiber used in the dry method, when a sheet layer is produced from alumina fiber, the average length of the alumina fiber is generally about 20 to 200 mm, and the thickness (average diameter) is generally About 1 to 40 μm. The alumina fibers may have a mullite composition having an Al ₂ O ₃ / SiO ₂ weight ratio in the range of about 70/30 to 74/26.

  Next, the manufacturing method of the 1st sheet layer 21 and the 2nd sheet layer 22 is demonstrated. The first sheet layer 21 is produced by a dry method, more specifically by a needle punch method, whereas the second sheet layer 22 is produced by a wet method (wet lamination method). Therefore, the first sheet layer 21 is a dry layer, and the second sheet layer 22 is a wet layer.

The manufacturing method (dry method) of the first sheet layer 21 is as follows. First, an alumina fiber precursor is obtained by spinning a sol gel composed of a mixture of an alumina source such as aluminum oxychloride, a silica source such as silica sol, an organic binder such as polyvinyl alcohol, and water. Subsequently, the alumina fiber precursor is laminated in a sheet shape, subsequently needle punched, and further baked at a high temperature within a range of about 1000 to 1300 ° C., whereby the first sheet layer 21 is obtained. The density of the needle punch is, for example, about 1 to 50 punches / cm ² , and the thickness, bulk specific gravity, and strength of the mat can be adjusted by changing the density.

  On the other hand, the second sheet layer 22 is prepared by mixing inorganic fibers and organic binders as starting materials with arbitrary additives, and then opening the inorganic fibers, preparing a slurry, molding by papermaking, pressurizing the mold, etc. It can be obtained by continuously performing the process. For details of the wet method (wet lamination method), it is possible to refer to WO 2004/061279 and US Pat. No. 6,051,193. In addition, the kind of organic binder and its usage-amount are not specifically limited. For example, an acrylic resin, a styrene-butadiene resin, an acrylonitrile resin, a polyurethane resin, a natural rubber, a polyvinyl acetate resin, or the like provided in the form of latex can be used as the organic binder. Alternatively, a flexible thermoplastic resin such as an unsaturated polyester resin, an epoxy resin, or a polyvinyl ester resin may be used as the organic binder.

  The first sheet layer 21 and the second sheet layer 22 have different hardness (Asker F-type hardness) and density due to such a difference in manufacturing method.

  The hardness of the first sheet layer 21 is 50 to 90, whereas the hardness of the second sheet layer 22 is 30 to 80. However, the hardness of the first sheet layer 21 is n times the hardness of the second sheet layer 22 (where 1 <n ≦ 3). That is, the second sheet layer 22 is softer than the first sheet layer 21.

The density of the first sheet layer 21 is 0.12 to 0.30 g / cm ³ , whereas the density of the second sheet layer 22 is 0.10 to 0.25 g / cm ³ . However, the density of the first sheet layer 21 is n times the density of the second sheet layer 22 (where 1 <n ≦ 3).

  The method of manufacturing the attachment system 20 having the first sheet layer 21 and the second sheet layer 22 is not limited. For example, the first sheet layer 21 and the second sheet layer 22 are bonded by any bonding means such as a normal adhesive, resin, or double-sided tape, or by a mechanical fixing means such as a stapler or stitching. The attachment system 20 may be obtained by joining. Alternatively, the slurry (suspension) prepared to produce the second sheet layer 22 is applied onto the surface of the first sheet layer 21, and the slurry is dehydrated by suction, whereby the first sheet layer The mounting system 20 may be obtained in which the second sheet layer 22 is fixed on 21.

  In the attachment system 20, the thickness of the 1st sheet layer 21 is 3-15 mm, and the thickness of the 2nd sheet layer 22 is 0.5-15 mm. However, the thickness of the second sheet layer 22 is equal to or less than the thickness of the first sheet layer 21. The ratio of the thickness of the first sheet layer 21 to the thickness of the second sheet layer 22 is 30: 1 to 1: 1.

  A plurality of shallow grooves 23 extending in a direction substantially perpendicular to the winding direction, that is, a groove pattern, is formed on the surface of the second sheet layer 22 that contacts the contamination control element 12 during winding. Therefore, when the mounting system 20 is wound around the pollution control element 12 and inserted into the casing 11, each groove 23 is positioned so as to extend along the axial direction of the catalytic converter 10. This groove pattern is formed by compressing the second sheet layer 22 with a plate (template) having a mold of the groove pattern on the surface in the process of manufacturing the mounting system 20. The interval between two adjacent grooves 23 may be arbitrarily determined, but may be 3 to 50 mm, for example.

  As described above, according to the present embodiment, the hardness of the first sheet layer 21 located outside at the time of attachment is n times the hardness of the second sheet layer 22 located inside at that time (however, 1 < n ≦ 3). By setting the hardness of the two sheet layers 21 and 22 in this way, when the contamination control element 12 is attached in the casing 11 and after the attachment, the contamination control element 12 is placed in the casing 11 with a stable and appropriate pressure. Can be fixed to. In addition, by forming a groove pattern on the surface of the second sheet layer 22 that contacts the contamination control element 12, the mounting system 20 is wound around the element 12 without causing uneven wrinkles on the inner surface of the mounting system 20. You can turn it on. As a result, it is possible to prevent the contamination control element 12 from being damaged by suppressing the occurrence of a portion where a higher pressure is applied than in the vicinity.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to an Example at all.

  First, an acrylic latex (Nippon ZEON) diluted with water to a needle-punched alumina fiber mat (trade name MAFTEC, manufactured by Mitsubishi Plastics, Inc.) composed of 72 wt% alumina and 28 wt% silica. The first sheet layer in a wet state was obtained by impregnating “Nippol LX-816A” manufactured by Co., Ltd.

  Subsequently, 94% by weight alumina silica fiber (made by Saffil Ltd.) composed of 96% by weight alumina and 4% by weight silica, and 6% by weight acrylic latex (manufactured by Nippon Zeon Co., Ltd.). "Nippol LX-816A") was mixed to obtain a slurry. And the 2nd sheet | seat layer was produced by spin-dry | dehydrating this slurry in a mesh form, and shape | molding it in a sheet form.

  Subsequently, an acrylic adhesive is applied on the wet first sheet layer, a second sheet layer is laminated thereon, and the molded product is compressed from above using a pressure press. The molded product was made dense. In this pressure press, since a template having a surface pattern in which linear convex portions having a cross section of an isosceles triangle and a height of 2.5 mm are arranged at intervals of 10 mm is used, the second sheet layer is used as the second sheet layer. Grooves were formed at intervals of 10 mm. Thereafter, the compressed first and second sheet layers were dried for 20 minutes in a drier set at 130 ° C. to obtain a two-layer mat.

The thickness and density of the first sheet layer were 7 mm and 0.17 g / cm ³ , respectively, and the thickness and density of the second sheet layer were 1.5 mm and 0.10 g / cm ³ , respectively. Therefore, the thickness of the entire mat was 8.5 mm.

  The mat obtained in this way was cut into a shape as shown in FIG. The length of the mounting system 120 was 350 mm and the width was 50 mm.

  The mounting system 190 according to the comparative example was also basically manufactured by the same method as the mounting system 120. However, in the comparative example, the pressure system is pressed using a simple flat plate having no protrusions for forming the groove pattern, so the mounting system 190 does not have the groove pattern. Only this point is different from the embodiment.

  When the monolith (manufactured by NGK Co., Ltd., trade name “HONEYCERAM”, 4.5 mil / 600 cell) 112 is fixed in the casing by the press-fitting method using the mounting system 120 or 190, The applied pressure was measured over time. The casing was manufactured using SUS409LT having a thickness of 1.5 mm. The gap between the monolith 112 and the casing was set so that the maximum pressure applied to the monolith surface when the monolith 112 was pushed into the casing was about 700 kPa.

  A sensor sheet (surface pressure measurement sheet, manufactured by Nitta Corporation) 200 was used for the pressure measurement. The sensor sheet 200 was placed between the monolith 112 and the mounting system. As shown in FIG. 5, the sensor sheet 200 includes 44 linear sensors 201 for measuring the circumferential direction of the monolith 112 (the winding direction of the mounting systems 120 and 190) by dividing it into 44 parts. For convenience, these sensors 201 are distinguished by numbers 1 to 44.

  The maximum pressure measured by each sensor 201 when the monolith 112 is pushed into the casing, and the average value of the pressure measured over time by each sensor 201 after the monolith 112 was inserted into the casing (this average value is the sensor 201 6 and 7 show the values for each. FIG. 6 is a graph showing measurement results for the example (mounting system 120), and FIG. 7 is a graph for the comparative example (mounting system 190). In each graph, the horizontal axis indicates the number of the sensor 201, and the vertical axis indicates the pressure (kPa). 6 and 7, the broken line indicates the maximum pressure, and the solid line indicates the average pressure in each sensor 201.

Table 1 shows the maximum pressure during mounting, the average pressure after mounting, and the difference between these two values for each of the examples and comparative examples. The maximum pressure in Table 1 is the maximum value through all the sensors 201, and the average pressure is a value obtained by further averaging the average values of the sensors 201.

  The present invention has been described in detail above based on the embodiments and examples. However, the present invention is not limited to the above embodiment. The present invention can be variously modified without departing from the gist thereof.

  The pollution control element may be a catalyst support (or catalyst element), a filter (eg, an exhaust gas purification filter for an engine), or any other pollution control element. Similarly, the pollution control device may be an exhaust gas purification device (eg, a diesel particulate filter) such as a catalytic converter, an exhaust gas purification device for an engine, or any other pollution control device with an attached pollution control element. Good.

  The mounting system may comprise more than two sheet layers. For example, an attachment system having one or more intermediate layers between the first sheet layer 21 and the second sheet layer 22 is also within the scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Catalytic converter (contamination control apparatus), 11 ... Casing, 12 ... Contamination control element, 12a ... Catalyst support, 13 ... Inlet, 14 ... Outlet, 20 ... Mounting system, 21 ... First sheet layer, 22 ... 2nd sheet layer, 23 ... groove, 31 ... internal combustion engine, 32 ... exhaust pipe, 112 ... monolith (catalyst carrier), 120 ... mounting system, 120, 190 ... mounting system, 190 ... mounting system.

Claims (11)

A casing, the pollution control device and a pollution control element disposed within the casing, to attach the pollution control element in said casing, a mounting system that is wound on the pollution control element,
A first sheet layer having a surface that contacts the casing when the contamination control element is installed ;
A second sheet layer positioned inside the first sheet layer when the contamination control element is attached;
A groove pattern is formed on the surface of the second sheet layer in contact with the contamination control element at the time of attachment;
The groove pattern is formed from one end to the other end of the second sheet layer in a direction substantially perpendicular to the winding direction;
The Asker F-type hardness of the first sheet layer is n times the Asker F-type hardness of the second sheet layer, where n is greater than 1 and less than or equal to 3;
The Asker F-type hardness of the first sheet layer is 50 to 90,
The Asker F-type hardness of the second sheet layer is 30-80.
Mounting system. The density of the first sheet layer is n times the density of the second sheet layer, where n is greater than 1 and less than or equal to 3;
The mounting system according to claim 1 . The density of the first sheet layer is 0.12 to 0.30 g / cm ³ ;
The density of the second sheet layer is 0.10 to 0.25 g / cm ³ .
The mounting system according to claim 2 . The thickness of the second sheet layer is equal to or less than the thickness of the first sheet layer.
The mounting system as described in any one of Claims 1-3 . The ratio of the thickness of the first sheet layer to the thickness of the second sheet layer is 30: 1 to 1: 1.
The mounting system according to claim 4 . The thickness of the first sheet layer is 3 to 15 mm,
The thickness of the second sheet layer is 0.5 to 15 mm.
The mounting system according to claim 5 . The first sheet layer is manufactured by a dry method,
The second sheet layer is produced by a wet method;
The mounting system according to any one of claims 1 to 6 . The groove pattern includes a plurality of grooves extending in a direction substantially orthogonal to the winding direction of the second sheet layer.
The mounting system according to any one of claims 1 to 7 . The interval between two adjacent grooves is 3 to 50 mm.
The mounting system according to claim 8 . A casing, the pollution control device and a pollution control element disposed within the casing, to attach the pollution control element in said casing, a mounting system that is wound on the pollution control element,
A first sheet layer having a surface that contacts the casing when the contamination control element is installed ;
A second sheet layer positioned inside the first sheet layer when the contamination control element is attached;
A groove pattern is formed on the surface of the second sheet layer in contact with the contamination control element at the time of attachment;
The groove pattern is formed from one end to the other end of the second sheet layer in a direction substantially perpendicular to the winding direction;
The density of the first sheet layer is n times the density of the second sheet layer, where n is greater than 1 and less than or equal to 3;
The density of the first sheet layer is 0.12 to 0.30 g / cm ³ ;
The density of the second sheet layer is 0.10 to 0.25 g / cm ³ .
Mounting system. A casing,
A pollution control element disposed within the casing;
A mounting system according to any one of claims 1 to 10 ,
The mounting system is disposed between the casing and the contamination control element to hold the contamination control element in a desired position within the casing;
Pollution control equipment.

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