JP2015117648A - Heat resisting cover against exhaustion system parts and its process of manufacturing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat resisting cover of simple structure against exhaustion system parts in which, even if it is directly fitted by a fitting member, there occurs a less possibility of production or no production of strain at its fitting part due to thermal expansion and shrinkage of the heat resisting cover, further with less or no fear of electrical corrosion.SOLUTION: This invention relates to a heat resisting cover 3 against exhaustion system parts C that is fitted to cover them while being adjacent thereto. The cover is comprised of cloth fabric 10 of a prescribed shape, including inorganic fibers, and a mixture 11 immersed in the cloth fabric. The mixture 11 contains inorganic binder, inorganic filler particles and water. The mixture is dried to have sufficient rigidity for holding the prescribed shape in the cloth fabric 10.

Description

  The present invention relates to a heat shield cover for exhaust system parts. In many cases, the heat shield cover is attached to an exhaust system part by an attachment member covering the exhaust system part. The heat shield cover can be used to prevent heat damage of exhaust system parts that become a high temperature of the internal combustion engine. The present invention also relates to a method for manufacturing the heat shield cover.

  Such a heat shield cover for exhaust system parts is already known as disclosed in Patent Document 1 below.

JP 2010-156372 A

  The heat insulation cover for exhaust system parts disclosed in Patent Document 1 is made of an aluminum plate having a relatively large thermal expansion coefficient. Therefore, in order to prevent distortion due to thermal expansion and contraction of the heat shield cover from occurring in the heat shield cover attachment portion and impairing its durability, a metal cover is not provided between the heat shield cover and the attachment member. Since the cushioning material is interposed, the structure around the mounting member becomes complicated, and measures against electric corrosion caused by dissimilar metals are required around the mounting member.

  The present invention has been made in view of such circumstances. The present invention has the following advantages, that is, the structure is simple, the direct attachment by the attachment member does not cause distortion due to the thermal expansion and contraction of the heat shield cover at the attachment portion, and there is a risk of electric corrosion. It is an object to provide a thermal barrier cover for exhaust system components having one or any combination of the absence. Another object of the present invention is to provide a method for manufacturing the heat shield cover.

  To achieve the above object, the present invention provides an exhaust system heat insulation cover that is adapted to be installed adjacent to and cover an exhaust system part, wherein the heat insulation cover comprises: A fabric comprising inorganic fibers and having a predetermined shape, and a mixture impregnated in the fabric, wherein the mixture includes an inorganic binder, inorganic filler particles, and water, and the mixture is dried and the mixture is dried. The first characteristic is that the fabric has sufficient rigidity to maintain the shape of the fabric.

  A suitable example of the exhaust system component is a catalytic converter. The fabric is preferably a woven fabric or a knitted fabric.

  In addition to the first feature, the present invention has a second feature that the fabric is provided with at least a part of a plurality of layers.

  According to a third aspect of the present invention, there is provided an exhaust system including an exhaust system component and a heat shield cover having a first feature that is attached adjacent to and covers the exhaust system component.

  Further, according to the present invention, in manufacturing the heat shielding cover for the exhaust system part of the first feature, the step of forming the fabric impregnated with the mixture into the predetermined shape with at least one mold, and heating the mold The fourth feature is that the step of drying the mixture to make the mixture sufficiently rigid to maintain the shape of the fabric is performed.

  Furthermore, in addition to the fourth feature of the present invention, a fifth feature is that a mold release means for preventing the mixture from adhering is interposed between the mold and the fabric.

  According to the first feature of the present invention, the heat insulating cover is composed of a fabric having a predetermined shape and a mixture that retains the shape of the fabric by impregnating and drying the fabric. It is excellent in that it can effectively prevent heat damage to various devices or objects adjacent to the heat shield cover, or can significantly reduce it. In addition, the thermal insulation cover has an extremely small coefficient of thermal expansion and has an appropriate flexibility, so that thermal expansion and contraction of exhaust system parts (for example, catalytic converter, exhaust manifold, muffler, particulate filter or trap). The thermal distortion does not occur in the attachment part to the exhaust system parts. Therefore, direct attachment by the attachment member of the heat shield cover is possible, the attachment structure can be simplified, and it can contribute to cost reduction. Furthermore, since the heat shield cover can be manufactured without using metal components, the concern of electrolytic corrosion at the mounting portion can be eliminated or can be significantly reduced.

  According to the second feature of the present invention, since the fabric is provided with at least a part of the multilayer, at least a part of the multilayer is able to improve the heat insulation and / or strength of the heat shield cover. it can.

  According to the third aspect of the present invention, there is provided an exhaust system that includes an exhaust system component and a heat shield cover that is mounted adjacent to and covers the exhaust system component. Can effectively prevent heat damage to other equipment or objects due to heat damage to the exhaust system parts arranged in the air or heat from the exhaust system parts located adjacent to the heat shield cover, or Can be reduced.

  According to a fourth aspect of the present invention, in manufacturing the heat insulation cover for the exhaust system component of the first aspect, a step of forming a fabric impregnated with the mixture into a predetermined shape with one or more molds; Heating the at least one mold and drying the mixture to make the fabric stiff enough to hold the predetermined shape, so that the mixture is removed by the mold, by one or more molds. A predetermined shape can be imparted to the impregnated fabric and the mixture can be dried, and a heat shield cover can be efficiently produced.

  According to the fifth feature of the present invention, since the mold release means to which the mixture is difficult to adhere is interposed between the mold and the fabric, the mold release means prevents the mixture from adhering to the mold. be able to. The release means corresponds to a release sheet 19 in one embodiment of the present invention described later. Said release means may also be a suitable release agent coating applied to the surface of the mold that will come into contact with the impregnated fabric.

The side view of the catalytic converter for exhaust purification which attached the heat shield cover of this invention. The perspective view of the said heat insulation cover. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. Sectional drawing which shows the state which set the raw material to the metal mold | die for shaping | molding in manufacture of the said heat insulation cover. Sectional drawing which shows the state which shape | molded the raw material in the heat-insulation cover with the metal mold | die.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  First, in FIG. 1, reference numeral C denotes a catalytic converter for purifying exhaust gas of an internal combustion engine of an automobile, for example. The catalytic converter C is disposed between the internal combustion engine and a dashboard (not shown) of the vehicle body with the longitudinal direction thereof directed vertically. An inlet flange 1 to which a downstream end of an exhaust manifold (not shown) of the internal combustion engine is joined is connected to the upper upstream end of the catalytic converter C, and an exhaust pipe (not shown) is connected to the lower downstream end. Each of the outlet flanges 2 is formed. Therefore, the catalytic converter C is a component of the exhaust system of the internal combustion engine. The catalytic converter C includes a member or structure adjacent to the catalytic converter C between the inlet flange 1 and the outlet flange 2, such as the dashboard. A heat shield cover 3 is attached to cover the side surface facing the. That is, as shown in FIGS. 1 and 4, cover stays 4 are fixed to a plurality of locations on the outer surface of the catalytic converter C by welding or the like, and each cover stay 4 includes a through hole 5 and a welding nut 6. Through holes 7 that coincide with the through holes 5 are provided at corresponding positions through the heat shield cover 3, and bolts 8 are screwed and tightened to the welding nut 6 through the through holes 6 and 7, thereby The cover 3 is fastened to the cover stay 4.

  As shown in FIGS. 2 and 3, the heat shield cover 3 includes an inorganic fiber fabric 10 that is given a predetermined shape so as to be on the outer surface of the catalytic converter C. An aqueous mixture 11 of an inorganic binder, inorganic filler particles, and water is impregnated into the fabric 10 and dried to retain the shape of the fabric 10. The woven fabric 10 can be made of heat-resistant fibers such as glass fibers.

  The fabric 10 may be an inorganic fiber (eg, continuous glass fiber, silica fiber, basalt fiber, polycrystalline, suitable for processing into a fabric such as one or any combination of woven and / or knit shapes, for example. Fiber, heat treated refractory ceramic fiber or combinations thereof). The fabric 10 preferably refers to a woven fabric, a knitted fabric or a combination of these types of fabrics. Only fabrics with sufficient structural strength are useful in the present invention. For example, it is desirable for a fabric according to the invention to exhibit sufficient strength (eg, tensile strength) to withstand impregnation with a mixture, molding, drying, and use as a heat shield. The fabric 10 according to the present invention may be made from the same or different types of fibers. As will be described herein, the fabric 10 of the thermal barrier cover 3 is saturated with the aqueous mixture 11 so that it becomes wet and supple, over most, most or at least most of its thickness. Coated, sprayed or impregnated. The fabric 10 can be impregnated with the aqueous mixture 11 before or after being formed into the shape of the heat shield cover 3. After impregnation, the heat shield cover 3 is supple. This is dried to form a rigid heat shield cover 3. As used herein, the term “drying” means that the supple heat shield cover 3 is heated at a sufficiently high temperature for a sufficiently long time to cure the supple heat shield cover (ie, the aqueous mixture), It refers to becoming a rigid heat shield cover (ie, a rigid mixture).

  The aqueous mixture used to impregnate the fabric 10 of the exemplary thermal barrier cover 3 is typically PCT International Application Publication No. WO 2013/044012 (A1), which is incorporated in its entirety into the above application. A slurry containing water, an inorganic binder and inorganic filler particles such as those disclosed in US Pat. The weight percent of each component in the slurry can vary, but typically a given slurry is about 20.0 weight percent (pbw) (and increased by 1 pbw) based on the total weight of the slurry. To about 54.0 and below (ie, 20.0 pbw, 21.0 pbw, 23.0 pbw, 24.0 pbw, 25.0 pbw ... 49.0 pbw, 50.0 pbw, 51.0 pbw, 52. 0 pbw, 53.0 pbw, 54.0 pbw) and any range thereof (eg, water ranging from about 25.0 pbw to 49.0 pbw and less, and about 1.0 pbw (and increased by 1 pbw)) One inorganic binder in the range including and below about 36.0 pbw and any range between them, and about 10.0 pbw (and increased by 1 pbw) From about 22.0 pbw to about 45, based on the total weight of a given slurry. 0.0pbw water or less, one or more inorganic binders in the range of about 5.0 pbw to about 30.0 pbw and less, and about 20.0 pbw to about 55.0 pbw of inorganic filler Particles.

  While not intending to limit their weight percentage of the thermal barrier cover composition, thermal barrier covers impregnated with those slurries contain from about 1% (and increased by 1%) to about 35%. Lower range (ie 1%, 2%, 3%, 4%, 5% ... 30%, 31%, 32%, 33%, 34% and 34%) and any range in between Inorganic binder particles can be included (for example, in a range including about 5% to about 30% or less). Thermal barrier covers made of fabric impregnated with those slurries range from about 5% (and increased by 1%) to about 75% and below, and any range in between. Inorganic filler particles can be included. Thermal barrier covers made of fabric impregnated with those slurries range from about 25% (and incremented by 1%) to about 65% and below, and any range in between. Inorganic fibers can be included. These percentages are based on dry weight.

  There is no limitation on the particle size of the inorganic binder material, but typically the inorganic binder comprises inorganic binder particles having a maximum particle size of about 200 nm, preferably a maximum particle size of about 100 nm. More typically, the inorganic binder comprises inorganic binder particles having a particle size ranging from about 1.0 nm (and increased by 1 nm) to about 100 nm and below, and any range therebetween. For example, the inorganic particles can include inorganic binder particles having a particle size of about 4.0 to about 60 nm.

  Furthermore, the particle size of the inorganic filler particles is not limited, but typically the inorganic filler particles have a maximum particle size of about 100 microns (μm). More typically, the inorganic filler particles have a particle size ranging from about 0.1 μm (and increased by 0.1 μm) to about 100 μm and below, and any range in between. be able to. For example, the inorganic filler particles can have a particle size in the range of about 0.2 μm to about 50 μm.

  The fabric 10 can be stacked in layers that are partially or completely overlapped. In the illustrated example, two layers of the impregnated fabric 10 partially overlap. The use of multiple layers of the fabric 10 is particularly desirable. For example, a portion of the heat shield cover 3 such as a portion that requires high heat shield properties (for example, a part of the heat shield cover 3 that covers a particularly high central portion of the catalytic converter C). It may be desirable in the part. Other areas where multiple layers of fabric 10 are desired are additional, such as a fastened portion (see, for example, the washer-shaped portion of fabric 10 shown in FIG. 4 that partially defines the through-hole 7). The part which requires the strong intensity | strength and / or toughness can be mentioned.

  The fabric 10 can be provided with a plurality of slit-shaped or round heat-dissipating holes 12 as necessary. In addition, many eyes formed by the fabric 10 can remain as ventilation holes without being filled with the mixture 11.

  Next, the operation of this embodiment will be described.

  The catalytic converter C of the exhaust system of the internal combustion engine purifies the exhaust gas during operation of the internal combustion engine and becomes high temperature due to the purification reaction heat. However, since the heat shield cover 3 covers the side surface of the catalytic converter C, The heat cover 3 blocks the radiant heat of the catalytic converter C and prevents thermal damage to various devices or objects adjacent to the catalytic converter C (for example, organic substances on the ground below the catalytic converter C).

  The heat insulating cover 3 is also excellent in sound insulating properties, and can effectively block the exhaust noise generated by the catalytic converter C.

  Further, the hot air generated around the catalytic converter C is dissipated to the outside through the heat radiation holes 12 of the heat shield cover 3 and the many eyes of the fabric 10 constituting the heat shield cover 3, and the catalytic converter C can be prevented from overheating.

  As described above, the heat insulating cover 3 is composed of the fabric 10 made of heat-resistant fibers and the mixture 11 impregnated and dried, so that the heat insulating cover 3 is excellent in heat insulation, and heat damage to adjacent various devices. Can be effectively prevented.

  Further, since the thermal insulation cover 3 has an extremely small coefficient of thermal expansion and has an appropriate flexibility, the thermal insulation cover 3 can follow the thermal expansion and contraction of the catalytic converter C. Does not occur. Therefore, direct fastening by the bolt 8 of the heat shield cover 3 is possible, which can contribute to cost reduction.

  Further, since the heat insulating cover 3 has an insulating property, there is no fear that electric corrosion occurs at the fastening portion by the bolt 8.

The following material combination examples have been selected only to further illustrate possible features, advantages and other details of the invention. However, while the examples serve this purpose, it will be clearly understood that the specific ingredients and amounts, as well as other conditions and details, should not be construed to unduly limit the scope of the present invention.
Examples The materials shown in Table 1 can be used according to the present invention.

  The slurry can be prepared using the components shown above. In each slurry, an inorganic material can be added to the liquid component and stirred using a high shear mixer until smooth to form the predetermined slurry shown in Table 2.

  Each exemplary fabric 10 is impregnated with a predetermined slurry to produce a supple heat shield cover 3, and then molded and dried by the following drying / heat treatment molding to form a rigid heat shield cover 3. can do.

  Next, an exemplary method for manufacturing the heat shield cover 3 will be described with reference to FIG.

  A pair of upper and lower molds 15 and 16 capable of press-molding the heat shield cover 3 are prepared. Heaters 17 and 17 are embedded in the molds 15 and 16, and a number of steam escape grooves 18, 18... Are provided on the opposing surfaces of the molds 15 and 16.

  In forming the heat shield cover 3, first, a release sheet 19 (for example, made of aluminum foil) is laid on the lower mold 16. The release sheet 19 is provided with a number of steam escape holes for releasing water in the mixture 11 when heated. The fabric 10 impregnated with the aqueous mixture 11 is placed on the release sheet 19. At that time, as described above, the fabric 10 impregnated with the mixture 11 is placed in multiple layers at the portion of the heat insulating cover 3 where high heat insulating properties are required or where the strength is required.

  Further, a release sheet 19 similar to the above is laid on the fabric 10, and then the upper mold 15 is lowered and the impregnated fabric 10 is clamped with the lower mold 16 as shown in FIG. A predetermined shape as the heat insulating cover 3 is given to the fabric 10 and the heat dissipating slits 12 are formed in the fabric 10 by the cooperation of both molds 15 and 16. Next, the heaters 17 are operated to dry the mixture 11 impregnated in the fabric 10. The steam generated at that time is discharged out of the molds 15 and 16 through the steam release holes of the release sheet 19 and the steam release grooves 18 of the molds 15 and 16. Thus, the dried and solidified mixture 11 maintains the shape of the fabric 10 applied by the molds 15 and 16 and constitutes the heat shield cover 3 together with the fabric 10. Thereafter, if the upper mold 15 is raised, the heat shield cover 3 can be taken out between the molds 15 and 16 together with the upper and lower release sheets 19 and 19. Thus, the release sheets 19 and 19 prevent the mixture 11 from adhering to the molds 15 and 16, and also prevent the mixture 11 from adhering to the release sheets 19 and 19 themselves. The cover 3 can be easily peeled off.

  According to such a manufacturing method, the pair of upper and lower molds 15 and 16 can impart the shape to the fabric 10 impregnated with the mixture 11 and dry the mixture 11, and efficiently manufacture the heat shield cover 3. can do.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention. For example, a reinforcing material such as a wire mesh or perforated steel sheet may be sandwiched between a plurality of stacked fabrics 10 or a reinforcing material may be provided on the surface. The material of the reinforcing material is not limited to metal, and may be a heat resistant resin or ceramic. Good. Further, the heat shield cover 3 can be attached to the catalytic converter C by a band or the like instead of the one or more bolts 8. In place of the release sheets 19 and 19, release powder can be used for the molds 15 and 16. The release sheets 19 and 19 may be replaced with a conventional release agent coating that adheres to the molds 15 and 16 but does not adhere to the heat shield cover 3. The shape of the heat shield cover can be freely selected according to the type and arrangement of exhaust system parts and the arrangement of adjacent members.

C ... Exhaust system parts (catalytic converter)
3 .... Heat shield cover 8 .... Mounting member (bolt)
10 ... Woven fabric 11 ... Clay 15, 16, ... Mold 19 ... Release means (release sheet)

Claims (9)

In a heat-insulating cover for an exhaust system component that is operably adapted to be mounted adjacent to and covering the exhaust system component (C),
A fabric (10) containing inorganic fibers, wherein the heat shield cover is given a predetermined shape;
The fabric (10) and the mixture (11) impregnated,
The mixture comprises an inorganic binder, inorganic filler particles and water;
A heat insulation cover for exhaust system parts, characterized in that the mixture is dried and has sufficient rigidity to maintain the shape of the fabric (10). The heat insulation cover for exhaust system parts according to claim 1,
A heat insulating cover for exhaust system parts, characterized in that the fabric (10) is provided with at least a part of multiple layers. The heat insulation cover for exhaust system parts according to claim 1 or 2,
When the inorganic filler particles are mixed with the inorganic binder in the presence of water, the inorganic filler particles include any fine particles that cause most of the inorganic binder to remain in the fabric (10). , Heat insulation cover for exhaust system parts. In the heat-insulating cover for exhaust system parts according to any one of claims 1 to 3,
Heat insulation cover for exhaust system parts, characterized in that the fabric (10) is a woven fabric, a knit fabric or a combination of both types. In the heat insulation cover of the exhaust system parts according to any one of claims 1 to 4,
The thermal barrier cover comprises inorganic binder particles in the range of about 1% to about 35%, inorganic filler particles in the range of about 5% to about 75%, and the range of about 25% to about 65% by weight. Heat insulation cover for exhaust system parts, characterized in that it contains inorganic fibers of the fabric and each percentage is based on dry weight. In the heat insulation cover of the exhaust system parts according to any one of claims 1 to 5,
The heat insulation cover for exhaust system parts, further comprising at least one attachment member (8) used for attaching the heat insulation cover adjacent to the exhaust system part (C).   It includes an exhaust system part (C) and the heat shield cover according to any one of claims 1 to 6, which is attached adjacent to and covers the exhaust system part (C). Exhaust system. In the manufacturing method of the thermal-insulation cover as described in any one of Claims 1-6,
Forming the fabric (10) impregnated with the mixture (11) into the predetermined shape with at least one mold (15, 16); heating the at least one mold (15, 16); A method of manufacturing a heat insulating cover for exhaust system parts, comprising: drying the mixture (11) to make the mixture (10) rigid enough to maintain the shape of the fabric (10). In the manufacturing method of the thermal-insulation cover of the exhaust system components of Claim 8,
A heat shielding cover for exhaust system parts, characterized in that a mold release means (19) to which the mixture (11) is difficult to adhere is interposed between the molds (15, 16) and the fabric (10). Manufacturing method.

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