Catalyst device

Abstract

The present invention addresses the problem of providing a catalyst device capable of improving the durability of a honeycomb core while maintaining the purification performance of combustion gas. In order to solve the problem, this catalyst device (30) is provided with a honeycomb core (31) in which a metal foil (40) on which a catalyst is supported is wound, a plurality of through-holes (H) are formed in a part of the metal foil (40), and the through-holes (H) are formed in the honeycomb core (31) in the flow direction of the combustion gas (G) passing through the honeycomb core (31). A first region (A) in which a through-hole (H) is not provided, a second region (B) in which a through-hole (H) is provided, and a third region (C) in which a through-hole (H) is not provided are arranged in this order from the upstream side. When the flow direction of the combustion gas (G) is the width direction, the width (TA) of the first region (A) is set to be smaller than the width (TC) of the third region (C). The metal foil (40) is formed by overlapping a flat foil piece (41) and a bump foil piece (42), and the first brazing part (51) is arranged at the upstream side end part of the honeycomb core (31) and joins the flat foil piece (41) and the bump foil piece (42).

Description

Technical Field

[0001] The present invention relates to a catalyst device, and more particularly to a catalyst device having a honeycomb core. The honeycomb core is formed by stacking metal foils carrying catalysts. Background Art

[0002] There is known a catalyst device that purifies combustion gas of an internal combustion engine by passing it through a honeycomb core formed by laminating metal foils carrying a catalyst such as platinum.

[0003] Patent document 1 discloses a catalyst device in which a plurality of through holes are provided on a metal foil to suppress two phenomena that are likely to occur when used at high temperatures, namely, thermal strain caused by the temperature difference inside the honeycomb core and the phenomenon that the metal foil itself is stretched due to the volume expansion of the oxide film formed on the surface of the metal foil.

[0004] [Prior Technical Literature]

[0005] [Patent Document]

[0006] Patent Document 1: Japanese Patent No. 5199291 Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] However, the honeycomb core of Patent Document 1 has through holes arranged in a checkerboard pattern throughout the metal foil. Therefore, when the combustion gas flows, the internal pressure fluctuation of the catalyst device increases. This pressure fluctuation may cause the brazing part of the honeycomb core to deteriorate, resulting in a problem that corresponding measures need to be taken.

[0009] An object of the present invention is to provide a catalyst device that can solve the above-mentioned problems of the prior art and improve the durability of the honeycomb core while maintaining the purification performance of the combustion gas.

[0010] [Technical means to solve the problem]

[0011] In order to achieve the above-mentioned object, the present invention is a catalyst device (30) having a honeycomb core (31), wherein the honeycomb core (31) is formed by winding a metal foil (40) carrying a catalyst, and the first feature of the catalyst device (30) is that a plurality of through holes (H) are formed in at least a portion of the metal foil (40), and in the flow direction of the combustion gas (G) passing through the honeycomb core (31), a first region (A) where the through holes (H) are not provided, a second region (B) where the through holes (H) are provided, and a third region (C) where the through holes (H) are not provided are arranged in sequence from the upstream side, and when the flow direction of the combustion gas (G) is set as the width direction, the width (TA) of the first region (A) is set to be smaller than the width (TC) of the third region (C).

[0012] In addition, a catalyst device (30) has a honeycomb core (31), wherein the honeycomb core (31) is formed by winding a metal foil (40) carrying a catalyst, and a second feature of the catalyst device (30) is that a plurality of through holes (H) are formed in at least a portion of the metal foil (40), and in the flow direction of the combustion gas (G) passing through the honeycomb core (31), a first region (A) where the through holes (H) are not provided and a second region (B) where the through holes (H) are provided are provided from the upstream side, and a third region (C) where the through holes (H) are not provided is provided from the downstream side, and when the flow direction of the combustion gas (G) is set as the width direction, the width (TA) of the first region (A) is set to be smaller than the width (TC) of the third region (C).

[0013] In addition, the third feature is that the aforementioned metal foil (40) is composed of overlapping a flat foil sheet (41) and a corrugated foil sheet (42), and a first brazing portion (51) is arranged at the end portion on the upstream side of the aforementioned honeycomb core (31) to join the aforementioned flat foil sheet (41) and the aforementioned corrugated foil sheet (42).

[0014] Moreover, the fourth characteristic is that the second region (B) is not brazed.

[0015] In addition, the fifth feature is that it includes: a second brazing portion (52) that joins the flat foil (41) and the corrugated foil (42) at a location further downstream than the first brazing portion (51); and a third brazing portion (53) that joins the honeycomb core (31) and the outer cylinder (32) that accommodates the honeycomb core (31); the second brazing portion (52) and the third brazing portion (53) overlap each other when the catalyst device (30) is viewed from the side.

[0016] In addition, a sixth feature is that the second brazed portion (52) and the third brazed portion (53) are provided at positions close to the downstream side of the catalyst device (30).

[0017] In addition, the seventh feature is that the width (T2) of the second soldering portion (52) is set smaller than the width (T3) of the third soldering portion (53).

[0018] Furthermore, an eighth feature is that a width (TB) of the second region (B) is set larger than a width (TC) of the third region (C).

[0019] (Effects of the Invention)

[0020] According to the first feature, the catalyst device (30) has a honeycomb core (31) formed by winding a metal foil (40) carrying a catalyst, a plurality of through holes (H) being formed in at least a portion of the metal foil (40), and a first region (A) where the through holes (H) are not provided, a second region (B) where the through holes (H) are provided, and a third region (C) where the through holes (H) are not provided are arranged in order from the upstream side in the flow direction of the combustion gas (G) passing through the honeycomb core (31), and when the flow direction of the combustion gas (G) is set as the width direction, the width (TA) of the first region (A) is set to be smaller than the width (TC) of the third region (C), so that, compared with a structure in which the through holes are formed in the entire metal foil, the combustion gas can be diffused in the first region on the upstream side where the through holes are not provided, thereby suppressing excessive internal pressure of the catalyst device. As a result, the durability of the honeycomb core can be improved while maintaining the purification performance of the combustion gas.

[0021] According to the second feature, the catalyst device (30) has a honeycomb core (31) formed by winding a metal foil (40) carrying a catalyst, a plurality of through holes (H) being formed in at least a portion of the metal foil (40), a first region (A) not provided with the through holes (H) and a second region (B) provided with the through holes (H) being provided from the upstream side in the flow direction of the combustion gas (G) passing through the honeycomb core (31), and a third region (C) not provided with the through holes (H) being provided from the downstream side, and when the flow direction of the combustion gas (G) is set as the width direction, the width (TA) of the first region (A) is set to be smaller than the width (TC) of the third region (C), so that, compared with a structure in which the through holes are formed in the entire metal foil, the combustion gas can be diffused in the first region on the upstream side where the through holes are not provided, thereby suppressing excessive internal pressure of the catalyst device. As a result, the durability of the honeycomb core can be improved while maintaining the purification performance of the combustion gas.

[0022] According to the third feature, the metal foil (40) is formed by overlapping a flat foil (41) and a corrugated foil (42), and a first brazing portion (51) is provided at the end portion on the upstream side of the honeycomb core (31), so that the flat foil (41) and the corrugated foil (42) are joined together, thereby increasing the joining strength of the end portion on the upstream side which is first contacted by the combustion gas, thereby suppressing damage to the metal foil.

[0023] According to the fourth feature, since the second region (B) is not brazed, pressure fluctuations and stress concentration caused by the entry of brazing material into the through-hole can be avoided, thereby improving the durability of the catalyst device.

[0024] According to the fifth feature, it includes: a second brazing portion (52) that joins the flat foil (41) and the corrugated foil (42) at a location further downstream than the first brazing portion (51); and a third brazing portion (53) that joins the honeycomb core (31) and the outer tube (32) that accommodates the honeycomb core (31); the second brazing portion (52) and the third brazing portion (53) overlap each other when the catalyst device (30) is viewed from the side, so that the second brazing portion suppresses the thermal strain phenomenon of the honeycomb core at a location closer to the downstream side of the catalyst device, thereby suppressing the deformation of the outer tube and improving the durability of the third brazing portion.

[0025] According to the sixth feature, the second brazing portion (52) and the third brazing portion (53) are arranged at a position closer to the downstream side of the catalyst device (30). Therefore, by arranging the second brazing portion and the third brazing portion at a position closer to the downstream side where the temperature is lower than that of the upstream side, the third brazing portion can be protected from heat and the honeycomb core can be prevented from falling off from the outer tube.

[0026] According to the seventh feature, the width (T2) of the second brazing portion (52) is set to be smaller than the width (T3) of the third brazing portion (53). Therefore, even if the third brazing portion is affected by the thermal strain phenomenon, the stress generated thereby can be easily dispersed in the second brazing portion, thereby suppressing the impact on the honeycomb core.

[0027] According to the eighth feature, the width (TB) of the second region (B) is set larger than the width (TC) of the third region (C), so that the purification performance of the catalyst device can be maintained by sufficiently increasing the area of ​​the second region where the through holes are provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a left side view of an exhaust device to which a catalyst device according to an embodiment of the present invention is applied.

[0029] Figure 2 yes Figure 1 Cross-sectional view along line II-II.

[0030] Figure 3 It is an oblique view of the catalyst device.

[0031] Figure 4 is a front view showing a honeycomb core structure.

[0032] Figure 5 It is a partially enlarged oblique view showing the honeycomb core structure.

[0033] Figure 6 is a schematic cross-sectional view showing the structure of a catalyst device. DETAILED DESCRIPTION

[0034] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 1 is a left side view of an exhaust device 1 to which a catalyst device 30 according to an embodiment of the present invention is applied. The direction arrows in the figure correspond to the direction of a vehicle such as a motorcycle to which the exhaust device 1 is mounted.

[0035] The exhaust device 1 includes an exhaust pipe 2 mounted on a cylinder head of an internal combustion engine (not shown), a catalyst storage section 4 connected to the rear of the exhaust pipe 2, and a muffler 6 connected to the rear of the catalyst storage section 4. Plate-shaped brackets 3 and 5 are provided on the catalyst storage section 4 and the muffler 6 for fixing the exhaust device 1 to the vehicle. The combustion gas G of the internal combustion engine is sent to the catalyst storage section 4 through the exhaust pipe 2, and after being purified by the catalyst device 30 stored in the catalyst storage section 4, it is silenced by the muffler 6 and discharged to the rear.

[0036] Figure 2 yes Figure 1 II-II line cross-sectional view. In addition, Figure 3 It is a perspective view of the catalyst device 30. The same reference numerals as those previously described indicate the same or equivalent parts as previously described. Figure 2 , “front” and “rear” of the direction arrows correspond to the upstream side and the downstream side of the combustion gas G, respectively.

[0037] The catalyst device 30 having a substantially cylindrical shape is configured such that a cylindrical honeycomb core 31 is housed in a cylindrical outer tube 32. The front end of the outer tube 32 is connected to a front tapered tube 9 connected to the exhaust pipe 2. On the other hand, the rear end of the outer tube 32 is connected to a rear tapered tube 11 connected to a tail pipe 12. The insulated tube 10 constituting the catalyst storage section 4 is wound around the radially outer side of the outer tube 32, and the front end of the insulated tube 10 is connected to the exhaust pipe 2 via an outer tapered tube 8.

[0038] Figure 4: is a front view showing the structure of the honeycomb core 31. The honeycomb core 31 is a honeycomb structure formed by winding a metal foil 40 multiple times, and the aforementioned metal foil 40 is formed by overlapping a flat foil sheet 41 carrying a catalyst such as platinum and a corrugated foil sheet 42. The flat foil sheet 41 and the corrugated foil sheet 42 can be formed, for example, of a ferritic stainless steel with a plate thickness of 30 to 100 μm. The manufacture of the honeycomb core 31 is carried out in the following manner: a flat foil sheet 41 and a corrugated foil sheet 42 with a brazing material such as nickel brazing material arranged at a specific position are overlapped to form the metal foil 40, and the metal foil 40 is wound, and the wound metal foil 40 is stored in the outer tube 32, and it is heated in a vacuum furnace and vacuum brazed.

[0039] Figure 5 : is a partially enlarged oblique view showing the structure of the honeycomb core 31. The same symbols as above represent the same or equivalent parts. The flat foil 41 and the corrugated foil 42 are joined to each other by brazing at the top of the peak and the top of the trough of the corrugated foil 42. A plurality of through holes H are formed on the flat foil 41 and the corrugated foil 42, respectively. The purpose of providing the through holes H is to prevent the following phenomenon, namely, the thermal strain phenomenon caused by the internal temperature difference of the honeycomb core 31, and the phenomenon that the metal foil 40 itself is stretched due to the volume expansion of the oxide film formed on the surface of the metal foil 40.

[0040] However, for example, when the through holes H are provided throughout the metal foil 40, the internal pressure fluctuation of the catalyst device 30 increases when the combustion gas G flows, and this pressure fluctuation may cause the brazing portion of the honeycomb core 31 to deteriorate, which may require corresponding measures. In response to this problem, the present invention can improve the durability of the honeycomb core 31 while maintaining the purification performance of the combustion gas G by intentionally providing an area where the through holes H are not provided.

[0041] Figure 6 : is a schematic cross-sectional view showing the structure of the catalyst device 30. The catalyst device 30 is characterized in that, in the honeycomb core 31 of the present embodiment, a first region A where no through holes H are provided, a second region B where through holes H are provided, and a third region C where no through holes H are provided are arranged in order from the upstream side of the combustion gas G. Furthermore, when the flow direction of the combustion gas G is set as the width direction, the width TA of the first region A is set to be smaller than the width TC of the third region C.

[0042] Thus, compared with a structure in which the through holes H are formed in the entire metal foil 40, the combustion gas G can be diffused in the first region A on the upstream side where the through holes H are not provided, thereby suppressing excessive increase in the internal pressure of the catalyst device 30. Thus, the durability of the honeycomb core 31 can be improved while maintaining the purification performance of the combustion gas G.

[0043] The through hole H can be used, for example, The circular holes are arranged in 33 rows in a zigzag shape. In addition, the diameter of the through hole H can be made smaller to increase the number of holes, or the shape can be made into a non-circular shape such as an ellipse. In this embodiment, the balance between purification performance and durability is studied, and as a result, the width TB of the second area B is set to about 1 / 2 of the total width.

[0044] The present invention is characterized in that the first brazing portion 51 is provided at the upstream end of the honeycomb core 31 to join the flat foil sheet 41 and the corrugated foil sheet 42. This can improve the joining strength of the upstream end where the combustion gas G first contacts, thereby suppressing damage to the metal foil.

[0045] In addition, in the present embodiment, brazing is not performed on the second region B provided with the through hole H. Thus, pressure fluctuation and stress concentration caused by the brazing material entering the through hole H can be avoided, and the durability of the catalyst device 30 can be improved.

[0046] The catalyst device 30 includes a second brazing portion 52, which joins the flat foil 41 and the corrugated foil 42 at a position closer to the downstream side. Further, the catalyst device 30 includes a third brazing portion 53, which joins the honeycomb core 31 and the outer cylinder 32 that accommodates the honeycomb core 31. In addition, in the present embodiment, the second brazing portion 52 and the third brazing portion 53 overlap each other when the catalyst device 30 is viewed from the side. Thus, the second brazing portion 52 can suppress the thermal strain phenomenon of the honeycomb core 31 at a position closer to the downstream side of the catalyst device 30, thereby suppressing the deformation of the outer cylinder 32 and improving the durability of the third brazing portion 53.

[0047] The second brazing portion 52 and the third brazing portion 53 are disposed at a position close to the downstream side of the catalyst device 30. This prevents the temperature of the second brazing portion 52 and the third brazing portion 53 from rising excessively, and in particular, prevents the second brazing portion 52 from deteriorating and causing the honeycomb core 31 to fall off from the outer tube 32 of the catalyst device 30.

[0048] In addition, the width T2 of the second brazing portion 52 is set to be smaller than the width T3 of the third brazing portion 53. Therefore, even if the third brazing portion 53 is affected by the thermal strain phenomenon, the stress generated thereby can be easily dispersed in the second brazing portion 52, thereby protecting the honeycomb core 31. Furthermore, the width TB of the second region B is set to be larger than the width TC of the third region C, so that by sufficiently increasing the area of ​​the second region B where the through hole H is provided, the purification performance of the catalyst device 30 can be maintained.

[0049] In the above embodiment, the width TA of the first region A and the width T1 of the first soldered portion 51 are set to be the same, but the widths thereof may be different from each other.

[0050] The form of the vehicle on which the exhaust device is installed, the shape or structure of the exhaust device, the shape or configuration of the catalyst device, the material of the flat foil and corrugated foil of the metal foil constituting the honeycomb core, the width of the first region, the second region, and the third region, the width or configuration of the first brazing portion, the second brazing portion, and the third brazing portion, the shape or size of the through hole, the number of through holes, etc. are not limited to the above-mentioned embodiments, and various changes can be made. For example, the catalyst device is not limited to a cylindrical shape, but can also be a shape with an elliptical cross-section, etc. In addition, the following situation is shown in the above-mentioned embodiment, that is, the first region without through holes, the second region with through holes, and the third region without through holes are arranged in sequence from the upstream side, but for example, between the second region and the third region, multiple regions without through holes and regions with through holes can also be sandwiched. The catalyst device of the present invention is not limited to motorcycles, and can also be applied to vehicles such as tricycles or four-wheeled vehicles, and exhaust devices of various devices using internal combustion engines as power sources.

[0051] Reference numerals

[0052] 1 Exhaust system

[0053] 30 Catalyst device

[0054] 31 Honeycomb core

[0055] 32 outer cylinder

[0056] 40 metal foil

[0057] 41 Flat Foil

[0058] 42 wave foil

[0059] 51 First Brazing Section

[0060] 52 Second brazing section

[0061] 53 Third brazing section

[0062] A. First Area

[0063] B. Second Area

[0064] C. Third Area

[0065] TA Width of the first area

[0066] TB Width of the second area

[0067] Width of the third region of TC

[0068] T1 Width of the first brazing portion

[0069] T2 Width of the second brazed portion

[0070] T3 Width of the third brazing section

[0071] H Through hole

[0072] G Combustion gas

Claims

1. A catalyst device (30) comprising a honeycomb core (31), wherein the honeycomb core (31) is formed by winding a metal foil (40) carrying a catalyst, A plurality of through holes (H) are formed in at least a portion of the metal foil (40), In the flow direction of the combustion gas (G) passing through the honeycomb core (31), a first region (A) where the through holes (H) are not provided, a second region (B) where the through holes (H) are provided, and a third region (C) where the through holes (H) are not provided are arranged in order from the upstream side, When the flow direction of the combustion gas (G) is set as the width direction, the width (TA) of the first region (A) is set to be smaller than the width (TC) of the third region (C).

2. A catalyst device (30) comprising a honeycomb core (31), wherein the honeycomb core (31) is formed by winding a metal foil (40) carrying a catalyst, A plurality of through holes (H) are formed in at least a portion of the metal foil (40), In the flow direction of the combustion gas (G) passing through the honeycomb core (31), a first region (A) without the through holes (H) and a second region (B) with the through holes (H) are provided from the upstream side, and a third region (C) without the through holes (H) is provided from the downstream side, When the flow direction of the combustion gas (G) is set as the width direction, the width (TA) of the first region (A) is set to be smaller than the width (TC) of the third region (C).

3. The catalyst device according to claim 1 or 2, wherein: The metal foil (40) is formed by overlapping a flat foil (41) and a corrugated foil (42). The first brazing portion (51) is provided at the upstream end of the honeycomb core (31) to join the flat foil sheet (41) and the corrugated foil sheet (42).

4. The catalyst device according to claim 1 or 2, wherein: In the catalyst device, the second region (B) is not brazed.

5. The catalyst device according to claim 3, wherein: The catalyst device comprises: a second brazing portion (52) for joining the flat foil (41) and the corrugated foil (42) at a position further downstream than the first brazing portion (51); and A third brazing portion (53) is used to join the honeycomb core (31) to an outer cylinder (32) that accommodates the honeycomb core (31); The second brazing portion (52) and the third brazing portion (53) overlap each other when the catalyst device (30) is viewed from the side.

6. The catalyst device according to claim 5, wherein: The second brazed portion (52) and the third brazed portion (53) are provided at positions close to the downstream side of the catalyst device (30).

7. The catalyst device according to claim 5, wherein: The width (T2) of the second soldering portion (52) is set smaller than the width (T3) of the third soldering portion (53).

8. The catalyst device according to claim 1 or 2, wherein: The width (TB) of the second region (B) is set to be larger than the width (TC) of the third region (C).

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