JP2013181413A - Catalyst converter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalyst converter device where stress of a catalyst carrier generated by a difference in a thermal expansion coefficient between a tube and a catalyst carrier can be alleviated.SOLUTION: A catalyst carrier 14 is retained via a retention mat 26 within a case tube 28. A lubrication layer 44 is provided between a retention mat 26 and the case tube 28.

Description

  The present invention relates to a catalytic converter device provided in an exhaust pipe of an internal combustion engine.

  In a catalytic converter device provided in an exhaust pipe for purifying exhaust gas generated in an internal combustion engine, for example, as described in Patent Document 1, a mat layer having an insulating layer and a fiber layer is provided inside a case cylinder. There is a structure having a catalyst support.

  By the way, the case cylinder and the catalyst carrier are thermally expanded by the heat of the exhaust gas. However, if the thermal expansion coefficients of the case cylinder and the catalyst carrier are different, the stress due to the difference in the expansion amount acts on the catalyst carrier. .

JP 2011-125767 A

  In view of the above facts, an object of the present invention is to obtain a catalytic converter device that can relieve the stress of the catalyst carrier caused by the difference in thermal expansion coefficient between the cylinder and the catalyst carrier.

  According to the first aspect of the present invention, a catalyst carrier that supports a catalyst for purifying exhaust gas discharged from the internal combustion engine, a cylindrical carrier that is attached to an exhaust pipe, and the catalyst carrier is accommodated therein. A cylinder, a one or more layers holding member disposed between the cylinder and the catalyst carrier and holding the catalyst carrier in the cylinder, the catalyst carrier and the holding member, the holding member; And a lubricating layer provided in at least one place between the cylindrical body and between the plurality of layers of the holding member.

  In this catalytic converter device, the catalyst carrier is attached to the exhaust pipe through one or more layers of holding members and a cylindrical body. When the exhaust gas passes through the catalyst carrier, harmful substances in the exhaust gas can be removed by the catalyst supported on the catalyst carrier.

  When the exhaust gas touches the cylinder and the catalyst carrier, the cylinder and the catalyst carrier thermally expand. If the thermal expansion coefficients of the cylinder and the catalyst carrier are different, the expansion amounts of the cylinder and the catalyst carrier are also different. In the present invention, a lubricating layer is provided at least at one position between the catalyst carrier and the holding member, between the holding member and the cylinder, and between the plurality of holding members. This lubrication layer causes slippage between the catalyst carrier and the holding member, or between the holding member and the cylinder, so that the above-described difference in expansion amount is absorbed. Thereby, the stress of the catalyst carrier can be relaxed.

  In the above-described “at least one place”, when the holding member has one layer, there is no layer between the holding members, and therefore at least one of the catalyst carrier and the holding member and between the holding member and the cylindrical body. If it is. On the other hand, when the holding member has a plurality of layers, there are layers of holding members. Therefore, the above “at least one place” may be any one place between the catalyst carrier and the holding member, between the holding member and the cylindrical body, and between the layers of the plurality of holding members.

  According to a second aspect of the present invention, in the first aspect of the invention, the catalyst carrier can be heated by energization, and has a pair of electrodes provided on the outer peripheral surface of the catalyst carrier for energizing the catalyst carrier. .

  A pair of electrodes is provided on the outer peripheral surface of the catalyst carrier, and the temperature of the catalyst carrier can be increased by heating the catalyst carrier through the electrodes. Thereby, the purification effect by the catalyst carry | supported by the catalyst support | carrier can be exhibited earlier.

  According to a third aspect of the present invention, in the second aspect of the present invention, the cylindrical body is made of metal, and the lubricating layer has an insulating property and protrudes in the exhaust flow direction from the holding member. Has an overhang.

  The exhaust gas may contain carbon generated by combustion of the internal combustion engine. When this carbon is impregnated in the holding member, current also flows through the carbon, which may reduce the efficiency of energization of the catalyst carrier. is there. In the present invention, since the lubricating layer has an insulating property, even if the holding member is impregnated with carbon, the catalyst carrier and the cylinder are not short-circuited via the carbon in the holding member.

  In particular, the lubricating layer has an overhanging portion that protrudes beyond the holding member in the exhaust flow direction. Therefore, the lubricant layer suppresses the carbon in the exhaust from adhering continuously (spread) from the catalyst carrier to the cylinder on the upstream side or downstream side of the holding member. Although the cylinder is made of metal, it can be prevented that the cylinder is short-circuited.

  Since the present invention has the above-described configuration, it is possible to relieve the stress of the catalyst carrier that occurs due to the difference in thermal expansion coefficient between the cylinder and the catalyst carrier.

1 is a cross-sectional view showing a catalytic converter device according to a first embodiment of the present invention in a cross section including a center line in an attached state to an exhaust pipe. It is sectional drawing which shows the catalytic converter apparatus of 2nd Embodiment of this invention in the cross section containing a centerline in the attachment state to an exhaust pipe. It is sectional drawing which shows the catalytic converter apparatus of 3rd Embodiment of this invention in the cross section containing a centerline in the attachment state to an exhaust pipe.

  FIG. 1 shows a catalytic converter device 12 according to a first embodiment of the present invention attached to an exhaust pipe 10.

  As shown in FIG. 1, the catalytic converter device 12 is a material having conductivity and rigidity (a conductive ceramic, a conductive resin, a metal, or the like can be applied, but in this embodiment, silicon carbide is used in particular). It has the catalyst support | carrier 14 formed by these. The catalyst carrier 14 is formed in a columnar shape or a cylindrical shape in which the surface area of the material is increased by configuring a thin plate having a honeycomb shape or a wave shape in a spiral shape or a concentric shape. A catalyst (platinum, palladium, rhodium, etc.) is supported on the surface of the catalyst carrier 14 in an attached state. The catalyst has an action of purifying harmful substances in the exhaust gas flowing in the exhaust pipe 10 (the flow direction is indicated by an arrow F1). Note that the structure for increasing the surface area of the catalyst carrier 14 is not limited to the honeycomb shape or the wave shape described above.

  Two electrodes 16A and 16B are attached to the catalyst carrier 14 at positions symmetrical with respect to the catalyst carrier 14 (up and down in FIG. 1). In the present embodiment, the lengths of the electrodes 16A and 16B are made shorter than that of the catalyst carrier 14 and are adhered to the outer peripheral surface of the catalyst carrier 14 at the center of the exhaust flow direction (arrow F1 and the opposite direction).

  Terminals 18A and 18B are connected to the electrodes 16A and 16B via conductor members 20A and 20B made of a conductive material such as metal, respectively. Each of the terminals 18A and 18B has a structure in which an insulating layer 24 covers the periphery of the central electrode rod 22. The outer end of the electrode rod 22 (the end opposite to the conductor members 20A and 20B) is a connection 22C to which a power supply cable to the catalyst carrier 14 is connected.

  The insulating layer 24 is formed in a cylindrical shape from a material having electrical insulation. The insulating layer 24 covers the outer peripheral surface of the electrode rod 22 over the entire circumference, thereby preventing the flow of electricity from the electrode rod 22 to the cover portion 36 of the case cylinder 28.

  The conducting wire members 20A and 20B are formed in, for example, a zigzag shape or a spiral shape so as to have flexibility, and when the case cylinder 28 and the catalyst carrier 14 are relatively moved as described later, It is possible to absorb this relative movement. The catalyst carrier 14 can be heated by energizing the catalyst carrier 14 from the terminals 18A and 18B through the conductor members 20A and 20B and the electrodes 16A and 16B. By this heating, the temperature of the catalyst supported on the catalyst carrier 14 is raised, so that the purification action of the catalyst can be exhibited at an early stage even immediately after the engine is started.

  The catalyst carrier 14 is held in a state of being accommodated inside a case cylinder (cylinder of the present invention) by a holding mat 26 (a holding member of the present invention) arranged on the outer periphery thereof. In other words, the catalyst carrier 14 is accommodated inside the substantially cylindrical case cylinder 28, and the catalyst carrier 14 is placed in the case by the holding mat 26 disposed between the case cylinder 28 and the catalyst carrier 14. The cylinder 28 is held concentrically (center line CL). Since the insulating holding mat 26 is disposed between the catalyst carrier 14 and the case cylinder 28, the flow of electricity from the catalyst carrier 14 to the case cylinder 28 is prevented.

  The case cylinder 28 is formed in a substantially cylindrical shape with a metal such as stainless steel, and on the upstream side in the flow direction, an upstream taper portion 28A whose diameter is gradually increased toward the downstream side, and an upstream taper in the middle portion in the flow direction. An intermediate portion 28B that is continuous from the portion 28A and has a larger diameter than the exhaust pipe 10, and a downstream tapered portion 28C that is continuous from the intermediate portion 28B and gradually decreases in diameter toward the downstream side in the longitudinal direction. Yes.

  The downstream end of the front pipe 10A of the exhaust pipe 10 is at the upstream end of the upstream tapered section 28A, and the upstream end of the rear pipe 10B of the exhaust pipe 10 is at the downstream end of the downstream tapered section 28C. They are connected to each other, and the flow passage cross-sectional area of the exhaust gas is locally enlarged at the portion of the case cylinder 28 (particularly the intermediate portion 28B).

  A through hole through which the terminals 18A and 18B are penetrated is formed in the intermediate portion 28B of the case cylinder 28 so as not to contact the terminals 18A and 18B. Further, a substantially cylindrical cover portion 36 that can accommodate the terminals 18A and 18B is provided from the intermediate portion 28B. In the state where the terminals 18 </ b> A and 18 </ b> B are inserted into the cover portion 36, the opening portion of the cover portion 36 is closed by the lid plate 38.

  In this embodiment, the holding mat 26 disposed on the outer periphery of the catalyst carrier 14 is formed in a single-layered substantially cylindrical shape. An intermediate portion 28 </ b> B of the case cylinder 28 is located on the outer periphery of the holding mat 26.

  The holding mat 26 is formed in a fiber shape having insulating properties and predetermined elasticity using, for example, an alumina mat, a resin mat, ceramic wool, or the like. Accordingly, the holding mat 26 itself has a predetermined elasticity, and the holding mat 26 is concentrically placed inside the substantially cylindrical case cylinder 28 with the catalyst carrier 14 compressed in the radial direction. (Center line CL). As a material constituting the holding mat 26, an interlam mat, mullite, or the like is also applicable.

  Note that the holding mat 26 exhibits a buffering action against the input of vibration through the exhaust pipe 10 and absorbs the positional deviation between the case cylinder 28 and the catalyst carrier 14.

  Further, since the insulating holding mat 26 is disposed between the catalyst carrier 14 and the case cylinder 28, the flow of electricity from the catalyst carrier 14 to the case cylinder 28 is prevented.

  The holding mat 26 is divided into two at positions corresponding to the conductor members 20 </ b> A and 20 </ b> B and the electrode rod 22 in the center in the axial direction. The electrodes 16A and 16B are positioned between the divided holding mats 26, and the holding mat 26 and the electrodes 16A and 16B are not in contact with each other. The holding mat 26 may be formed in a substantially cylindrical shape that is continuous from the upstream end surface 26A to the downstream end surface 26B without being divided into two in this way. In this case, holes that penetrate the holding mat 26 in the thickness direction may be provided at positions corresponding to the electrodes 16A and 16B, respectively, so that the holding mat 26 and the electrodes 16A and 16B are not in contact with each other.

  A lubricating layer 44 is disposed between the outer peripheral surface of the holding mat 26 and the case cylinder 28 (intermediate portion 28B). The lubricating layer 44 is formed in a thin cylindrical shape by, for example, applying boron nitride to at least one of the outer peripheral surface of the holding mat 26 and the inner peripheral surface of the intermediate portion 28B. Further, not only at a normal temperature but also in a state where the exhaust is in contact (a high temperature), a low friction coefficient is maintained with respect to at least one of the holding mat 26 and the case cylinder 28. In the present embodiment, the lubricating layer 44 also has an insulating property.

  In particular, since the metal case cylinder 28 and the silicon carbide catalyst carrier 14 have different coefficients of thermal expansion (linear expansion coefficients), the heat of the exhaust gas passing through the exhaust pipe 10 and the catalyst carrier 14 The amount of expansion due to current heating is different. This difference in the amount of expansion is partially absorbed by the elasticity of the holding mat 26, but in this embodiment, the lubricating layer 44 causes a slip between the holding mat 26 and the case cylinder 28. Differences are absorbed.

  In the present embodiment, the holding mat 26 is formed in the same length as the catalyst carrier 14 in the axial direction (exhaust flow direction). The upstream end surface 26A and the downstream end surface 26B of the holding mat 26 are in the same position in the axial direction (exhaust flow direction) as the upstream end surface 14A and the downstream end surface 14B of the catalyst carrier 14, respectively.

  On the other hand, the lubricating layer 44 includes an upstream projecting portion 44A that projects upstream from the upstream end surface 26A of the holding mat 26 on the upstream side in the axial direction. Similarly, on the downstream side in the axial direction, a downstream projecting portion 44B that projects downstream from the downstream end surface 26B of the holding mat 26 is configured.

  Next, the operation of the catalytic converter device 12 of this embodiment will be described.

  As shown in FIG. 1, the catalytic converter device 12 is attached so that the case cylinder 28 is concentric with the exhaust pipe 10 in the middle of the exhaust pipe 10 (between the front pipe 10A and the rear pipe 10B). Exhaust gas passes through the inside of the catalyst carrier 14. At this time, the substance (HC or the like) in the exhaust gas is purified by the catalyst supported on the catalyst carrier 14.

  In the catalytic converter device 12 of this embodiment, the catalyst carrier 14 is heated by energizing the catalyst carrier 14 by the terminals 18A and 18B, the conductor members 20A and 20B, and the electrodes 16A and 16B, thereby heating the catalyst carrier 14. The temperature can be raised, and the purification action can be exhibited earlier. For example, when the temperature of the exhaust gas is low, such as immediately after starting the engine, the catalyst purification performance in the initial stage of engine starting can be ensured by conducting energization heating to the catalyst carrier 14 in advance.

  When the exhaust gas contacts the catalyst carrier 14 and the case cylinder 28, the catalyst carrier 14 and the case cylinder 28 are thermally expanded. Since the material constituting the catalyst carrier 14 (silicon carbide in this embodiment) and the material constituting the case cylinder 28 (metal such as stainless steel in this embodiment) have different thermal expansion coefficients (linear expansion coefficients), The amount of expansion when expanding is also different.

  Therefore, for example, in a configuration without the lubricating layer 44, a part of the difference in the expansion amount described above is absorbed by the deformation of the holding mat 26, but there is a possibility that a large stress acts on the catalyst carrier 14. And in order to prevent the damage (for example, a crack etc.) resulting from the stress of the catalyst carrier 14, there are cases where the catalyst carrier 14 has a restriction such as decreasing the porosity.

  On the other hand, in this embodiment, since the lubricating layer 44 is provided between the holding mat 26 and the case cylinder 28, the holding mat 26 and the case cylinder 28 are compared with the configuration without the lubricating layer 44. And is slippery. For this reason, the above-described difference in expansion amount between the catalyst carrier 14 and the case cylinder 28 (part of which is absorbed by the deformation of the holding mat 26) is caused by the slip between the holding mat 26 and the case cylinder 28. It can absorb and relieve the stress of the catalyst carrier 14. In other words, the deformation (elongation) of the case cylinder 26 in the flow direction of the catalyst carrier 14 can be allowed by slipping by the lubricating layer 44. For example, even if the surface area of the catalyst carrier 14 is increased to increase the surface area (more catalyst can be supported), damage due to stress can be suppressed. For example, by setting the porosity of the catalyst carrier 14 to 30% or more and 60% or less, it is possible to obtain a large surface area for supporting a larger amount of catalyst and to suppress damage (cracks, etc.) due to the above-described stress. .

  In addition, the holding mat 26 does not need to absorb the difference in expansion between the catalyst carrier 14 and the case cylinder 28 by the deformation of the holding mat 26. Accordingly, it is possible to reduce the amount of material used by reducing the thickness of the holding mat 26 or the like.

  A difference in expansion amount in the radial direction (direction perpendicular to the center line CL) due to thermal expansion of the catalyst carrier 14 and the case cylinder 28 can be absorbed by elastic deformation of the holding mat 26.

  The exhaust gas contains carbon, and if the catalyst carrier 14 and the case cylinder 28 are electrically short-circuited by the carbon, the energization efficiency of the catalyst carrier 14 may be reduced. For example, if the carbon in the exhaust is impregnated in the holding mat 26 together with moisture, the catalyst carrier 14 and the case cylinder 28 are electrically short-circuited through the carbon in the holding mat 26. As a result, there is a concern that the heating efficiency of the catalyst supported on the catalyst carrier 14 also decreases.

  In the catalytic converter device 12 of this embodiment, the lubricating layer 44 has an insulating property. Therefore, as described above, even if the holding mat 26 is impregnated with carbon, an electrical short circuit between the catalyst carrier 14 and the case cylinder 28 is suppressed by the lubricating layer 44.

  Even when the holding mat 26 is not impregnated with carbon, it may adhere to the upstream end face 26A or the downstream end face 26B. For example, in the configuration without the lubricating layer 44 or the configuration without the upstream projecting portion 44A or the downstream projecting portion 44B even with the lubricating layer 44, it adheres to the upstream end surface 26A or the downstream end surface 26B. There is a possibility that the carbon spreads and the catalyst carrier 14 and the case cylinder 28 are electrically short-circuited.

  However, in the catalytic converter device 12 of the present embodiment, the lubricating layer 44 has the upstream projecting portion 44A and the downstream projecting portion 44B. Therefore, even if the carbon adhering to the upstream end surface 26A and the downstream end surface 26B spreads, the carbon does not adhere to the case cylinder 28 in the range where the upstream overhanging portion 44A and the downstream overhanging portion 44B exist, and the catalyst An electrical short circuit between the carrier 14 and the case cylinder 28 is suppressed by the lubricating layer 44.

  FIG. 2 shows a catalytic converter device 52 according to a second embodiment of the present invention. In the catalytic converter device 52 of the second embodiment, the same components, members and the like as those of the catalytic converter device 12 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the catalytic converter device 52 of the second embodiment, the holding mat 26 is also divided into two in the radial direction, and has an inner peripheral holding mat 26N and an outer peripheral holding mat 26G.

  Further, unlike the catalytic converter device 12 according to the first embodiment, the lubricating layer 44 (see FIG. 1) between the holding mat 26 and the case cylinder 28 is not provided. An intermediate cylinder 56 is provided between the side holding mat 26N and the outer peripheral side holding mat 26G.

  The intermediate cylinder 56 is formed in a cylindrical shape by a member having heat resistance against exhaust. In the intermediate cylinder 56, the length of the exhaust flow direction (arrow F1 direction) is longer than that of the holding mat 26, and the upstream protruding portion 56A that protrudes upstream from the upstream end face 26A of the holding mat 26 And a downstream protrusion 56B that protrudes further downstream than the downstream end face 26B.

  A lubricating layer 54 is provided on at least one of the inner peripheral surface and the outer peripheral surface of the intermediate tube 56 (the entire intermediate tube 56 including both surfaces in the example of FIG. 2). The lubricating layer 54 is formed in a thin film shape by applying boron nitride to the entire periphery of the intermediate cylinder 56, similarly to the lubricating layer 44 according to the first embodiment. And the low friction coefficient is maintained with respect to the inner peripheral side holding mat 26N and the outer peripheral side holding mat 26G in the normal temperature state and the high temperature state. Also in the second embodiment, the lubricating layer 54 has an insulating property.

  In the lubricating layer 54, the portion provided in the upstream protruding portion 56 </ b> A of the intermediate cylinder 56 is the upstream protruding portion 54 </ b> A, and the portion provided in the downstream protruding portion 56 </ b> B of the intermediate cylinder 56 is the downstream protruding portion. It is part 54B.

  Also in the catalytic converter device 52 of the second embodiment configured as described above, the substance (HC or the like) in the exhaust gas can be purified by the catalyst supported on the catalyst carrier 14. Further, the catalyst carrier 14 is energized by the terminals 18A and 18B, the conductor members 20A and 20B, and the electrodes 16A and 16B, and the catalyst carrier 14 is heated, so that the temperature of the catalyst carried on the catalyst carrier 14 is raised and the purification action is achieved. It can be demonstrated earlier.

  Even when the expansion amount of the catalyst carrier 14 and the case cylinder 28 is different due to the heat of exhaust gas, the inner cylinder 56 and the outer cylinder holding mat 26G are interposed between the inner cylinder 56N and the intermediate cylinder 56, and the intermediate cylinder 56 and the outer cylinder holding mat 26G. The difference in expansion amount is absorbed by the sliding of the lubricating layer 54 between the two and the stress of the catalyst carrier 14 can be relaxed. Also in the second embodiment, it is not necessary to absorb the difference in expansion between the catalyst carrier 14 and the case cylinder 28 by the deformation of the holding mat 26. For this reason, the amount of material used for the holding mat 26 can be reduced.

  Also in the catalytic converter device 52 of the second embodiment, even when the holding mat 26 is impregnated with carbon by water absorption or the like, the lubricating layer 54 has an insulating property, so the catalyst carrier 14, the case cylinder 28, The electrical short circuit is suppressed.

  In particular, in the second embodiment, the intermediate cylinder 56 has an upstream protruding portion 56A and a downstream protruding portion 56B, and the lubricating layer 54 is also more axial than the upstream end surface 26A and the downstream end surface 26B of the holding mat 26. It extends to a position protruding in the direction. For this reason, even if the carbon adhering to the upstream end face 26A or the downstream end face 26B spreads, the carbon is suppressed from continuing from the catalyst carrier 14 to the case cylinder 28, and the catalyst carrier 14 and the case cylinder 28 An electrical short circuit is suppressed by the lubricating layer 44.

  As the lubricating layer 54 according to the second embodiment, boron nitride can be used similarly to the lubricating layer 44 according to the first embodiment, and furthermore, by applying a heat-resistant glass coat having a sufficiently smooth surface. The lubricating layer 54 can be used.

  In particular, boron nitride has a higher thermal conductivity than the material of the case cylinder 28 (for example, stainless steel). Therefore, in the first embodiment and the second embodiment, when boron nitride is used as the lubricating layers 44 and 54, the heat of the catalyst carrier 14 is easily transmitted, and the combustion of carbon adhering to the surface of the case cylinder 28 is promoted. Is possible. By promoting the carbon fuel in this way, the insulation between the catalyst carrier 14 and the case cylinder 28 can be more effectively enhanced.

  In the second embodiment, a configuration in which a lubricating layer is simply provided between a plurality of holding mats 26 without providing the intermediate cylinder 56 may be adopted. In the configuration in which the holding mat 26 has three or more layers, it is sufficient that a lubricating layer (including one provided in the intermediate cylinder) is provided between any layers of the holding mat 26, and lubrication is performed between all the layers. A layer may be provided. Further, similarly to the first embodiment, it may be provided between the outer peripheral surface of the holding mat 26 and the case cylinder 28 (intermediate portion 28B) or between the inner peripheral surface of the holding mat 26 and the outer peripheral surface of the catalyst carrier 14. Good.

  FIG. 3 shows a catalytic converter device 62 according to a third embodiment of the present invention. In the catalytic converter device 62 of the third embodiment, the same components, members and the like as those of the catalytic converter device 12 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the catalytic converter device 62 of the third embodiment, the terminals 18A and 18B, the conductor members 20A and 20B, and the electrodes 16A and 16B are not provided, and the catalyst carrier 14 is not energized. Accordingly, the hole or the like through which the electrode rod 22 or the conductor members 20A and 20B are inserted is not formed in the intermediate portion 28B of the case cylinder 28. In FIG. 3, the holding mat 26 is divided into two in the flow direction (the direction of the arrow F1). However, in the third embodiment, it is not necessary to divide the holding mat 26 in this way.

  In the catalytic converter device 62 of the third embodiment, a lubricating layer 64 is provided between the holding mat 26 and the case cylinder 28. However, unlike the first embodiment, the length of the lubricating layer 64 in the flow direction is the same as that of the holding mat 26, and the upstream side overhanging portion 44A and the downstream side overhanging portion 44B (both refer to FIG. 1) Not provided.

  In the catalytic converter device 62 of the third embodiment configured as described above, when exhaust gas passes through the inside of the catalyst carrier 14, substances (HC and the like) in the exhaust gas are purified by the catalyst carried on the catalyst carrier 14. The

  Further, when the catalyst carrier 14 and the case cylinder 28 are expanded due to the heat of the exhaust, even if the expansion amounts are different, the difference in the expansion amount is caused by the slip of the lubricating layer 64 between the holding mat 26 and the case cylinder 28. Since it absorbs, the stress of the catalyst carrier 14 can be relaxed. Furthermore, also in the third embodiment, it is not necessary to absorb the expansion amount difference between the catalyst carrier 14 and the case cylinder 28 by the deformation of the holding mat 26. For this reason, the amount of material used for the holding mat 26 can be reduced.

  In the catalytic converter device 62 of the third embodiment, since the catalyst carrier 14 is not energized, the lubricating layer 64 does not need to have an insulating property. Therefore, it is possible to use a wider range of materials compared to the first embodiment and the second embodiment. For example, expanded graphite or molybdenum disulfide can be used.

  In each of the embodiments described above, the portion where the lubricating layers 44, 54, and 64 are provided is not particularly limited as long as the difference in expansion between the catalyst carrier 14 and the case cylinder 28 can be absorbed by sliding. For example, in the catalytic converter device 12 of the first embodiment, the lubricating layer 44 may be provided between the catalyst carrier 14 and the holding mat 26. In the catalytic converter device 52 of the second embodiment, the intermediate cylinder 56 is provided, but is positioned between the intermediate cylinder 56 and at least one of the inner peripheral holding mat 26N and the outer peripheral holding mat 26G. The lubricating layer 54 may be provided on either the inner peripheral side or the outer peripheral side of the intermediate cylinder 56. Also in the catalytic converter device 62 of the third embodiment, a lubricating layer 64 may be provided between the catalyst carrier 14 and the holding mat 26.

10 exhaust pipe 12 catalytic converter device 14 catalyst carrier 16A, 16B electrode 26 holding mat (holding member)
26G Outer peripheral holding mat 26N Inner peripheral holding mat 28 Case cylinder 44 Lubricating layer 44A Upstream overhanging portion 44B Downstream overhanging portion 52 Catalytic converter device 54 Lubricating layer 54A Upstream overhanging portion 54B Downstream overhanging portion 62 Catalytic converter device 64 Lubrication layer

Claims (3)

A catalyst carrier carrying a catalyst for purifying exhaust gas discharged from the internal combustion engine;
A cylindrical body that is formed in a cylindrical shape and is attached to the exhaust pipe and in which the catalyst carrier is accommodated;
One or more layers of holding members that are arranged between the cylinder and the catalyst carrier and hold the catalyst carrier in the cylinder;
A lubricating layer provided in at least one place between the catalyst carrier and the holding member, between the holding member and the cylinder, and between the plurality of layers of the holding member;
A catalytic converter device. The catalyst carrier can be heated by energization,
The catalytic converter device according to claim 1, further comprising a pair of electrodes provided on an outer peripheral surface of the catalyst carrier for energizing the catalyst carrier. The cylinder is made of metal,
3. The catalytic converter device according to claim 2, wherein the lubricating layer has an insulating portion and has an overhanging portion that protrudes in a flow direction of the exhaust gas from the holding member.

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