Catalytic converter for exhaust gas aftertreatment with improved structure
Patent Information
- Application Number
- CN202380047803.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-07-07
- Filing Date
- 2023-06-30
- Publication Date
- 2025-02-07
AI Technical Summary
Existing catalytic converters require the use of smooth metal foils between structured metal foils, resulting in increased heat capacity of the honeycomb body, increased heating time, and higher production costs. Meanwhile, the tilted flow channel cannot use the support pin, and the metal foil is prone to damage.
A catalytic converter is designed, wherein the honeycomb body is formed by winding at at least one metal foil, and the flow passage is oriented at different angles in each axial section, including arranged parallel to the central axis and inclined, alternately increasing the deflection point at Radius reduces material load and improves the flexibility of the honeycomb body through slots.
It reduces the material load caused by the corrugation process, reduces the risk of metal foil damage, simplifies the construction of honeycombs, reduces material requirements, and improves the flexibility and durability of the catalytic converter.
Smart Images
Figure CN119403999A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a catalytic converter for exhaust gas aftertreatment of an internal combustion engine, the catalytic converter having a honeycomb body formed by winding at least one metal foil, wherein the honeycomb body has a central axis, the central axis extends along the axial extension direction of the honeycomb body from the air inlet side of the honeycomb body toward the air outlet side of the honeycomb body, and the honeycomb body has a plurality of flow channels, through which air can flow from the air inlet side of the honeycomb body toward the air outlet side. Background Art
[0002] In order to convert harmful substances in the exhaust gas emitted by the internal combustion engine, a metal catalytic converter is installed in the exhaust system. In order to shorten the heating time of the installed catalytic converter, an electrically heatable heating plate can be installed upstream of the catalytic converter. In a catalytic converter with a metal honeycomb body, the heating plate is held by a so-called support pin, which is connected to the auxiliary catalytic converter in a material-locking manner on one side and to the heating plate in a material-locking manner on the other side. The support pin is used on the one hand to mechanically fix the heating plate relative to the catalytic converter and on the other hand to electrically insulate the heating plate from the catalytic converter.
[0003] Such catalytic converters, which are used as auxiliary catalytic converters for supporting heating plates, are usually produced by stacking and winding a plurality of metal foils on top of one another, wherein the metal foils are alternately designed to be smooth and structured. The honeycomb body produced by winding is inserted into a supporting housing, whereby the final shape of the catalytic converter is obtained. The flow channels formed between the smooth and structured foils are straight and extend regularly parallel to the center axis of the catalytic converter.
[0004] Alternatively, catalytic converters are known which do not have smooth foils. In order to nevertheless form flow channels in the honeycomb body through which the gas can flow from the inlet side to the outlet side, the foils are structured so that the resulting flow channels extend at an angle to the central axis. This results in so-called cross-corrugations or so-called herringbone structures.
[0005] Stacking the structured foils on top of each other in a correspondingly opposite orientation to the corrugations prevents the structured foils from sliding into each other.
[0006] The disadvantages of the devices of the prior art are, in particular, that the catalytic converter is designed without a smooth layer and has obliquely arranged flow channels on both the inlet and outlet sides of the catalytic converter, which flow channels are not parallel to the central axis of the catalytic converter. The support pins mentioned above cannot be used in such obliquely arranged channels. A further disadvantage is that the base layer, i.e. the metal foil, which forms the honeycomb body of the catalytic converter can be easily damaged due to the small bending radii usually used.
[0007] The use of an auxiliary catalytic converter with smooth metal foils between structured metal foils is disadvantageous because the heat capacity of the honeycomb body is increased as a result. This in turn increases the heating time to reach the optimum operating temperature. In addition, honeycomb bodies with smooth metal foils are more expensive to produce because of their higher material requirements. Summary of the invention
[0008] The object of the present invention is therefore to realize a catalytic converter for exhaust gas aftertreatment, which has a design optimized for the metal foils used and in particular does not require the use of smooth metal foils between structured metal foils and has a high flexibility of the honeycomb body in the axial direction and / or tangential direction.
[0009] With regard to the catalytic converter, this object is achieved by a catalytic converter having the features of claim 1 .
[0010] One embodiment of the present invention relates to a catalytic converter for exhaust gas aftertreatment of an internal combustion engine, wherein the catalytic converter has a honeycomb body formed by winding at least one metal foil, wherein the honeycomb body has a central axis, and the central axis extends along an axial extension direction of the honeycomb body from an air inlet side of the honeycomb body toward an air outlet side of the honeycomb body, and the honeycomb body has a plurality of flow channels, through which air can flow from the air inlet side to the air outlet side of the honeycomb body, wherein the honeycomb body is divided into individual axial sections along its axial extension direction, and the central axis extends along the axial extension direction, wherein the axial sections have flow channel sections, and the flow channel sections extend at different angles relative to the central axis.
[0011] An axial segment describes a region along the axial direction of extension of the honeycomb body. The entire axial segment forms the entire honeycomb body including its axial direction of extension. The individual axial segments are produced by specially shaped regions in the metal foil used. The honeycomb body is preferably produced from a single wound layer stack, so that all axial segments formed in the honeycomb body are formed from the same metal foil.
[0012] A plurality of flow channels formed between the metal foils extend from the gas inlet side to the gas outlet side of the honeycomb body.
[0013] According to the invention, the flow channels are characterized in that they can have different orientations with respect to the center axis of the honeycomb body within individual axial sections. The flow channels within an axial section can, for example, extend parallel to the center axis, be arranged at a positive angle to the center axis, or be arranged at a negative angle to the center axis.
[0014] At the transition between the individual axial sections, the respective flow direction in the individual flow channels is therefore deflected.
[0015] The alternation of straight axial sections with flow channels extending parallel to the central axis and axial sections with obliquely arranged flow channels increases the radius at the deflection point and thus reduces the material load caused by the corrugation process. This reduces the occurrence of damage to the metal foil during the production process.
[0016] The catalytic converter according to the invention has a honeycomb body which is designed without a smoothing layer which is usually used to separate structured metal foils in order to prevent the metal foils from sliding into each other. This makes the construction of the honeycomb body simpler and requires less material.
[0017] Depending on the configuration, the orientation of the flow channels in the axial sections can be respectively different, flow channels oriented parallel to the central axis alternating with flow channels arranged at an angle to the central axis.
[0018] It is particularly advantageous if each flow channel has a flow channel section corresponding to the number of axial sections, wherein each flow channel section extends along one of the axial sections. All flow channels extend from the inlet side to the outlet side of the catalytic converter. Thus, each flow channel passes through all axial sections of the catalytic converter.
[0019] Since the honeycomb body is produced only from the layer stack in the axial direction and the metal foil is therefore not interrupted, each flow channel extends through an axial section without being interrupted by the transition between the axial sections. The goal is to achieve as much flow through the honeycomb body as possible and thus block the flow channels as little as possible. Due to the manufacturing technology, individual flow channels may deform and thus become blocked. However, these are insignificant side effects that do not fundamentally change the function and structure of the honeycomb body.
[0020] It is also advantageous if the axial section flow channel section starting at the gas inlet side of the honeycomb body extends parallel to the central axis of the honeycomb body and / or the axial section flow channel section ending at the gas outlet side of the honeycomb body extends parallel to the central axis.
[0021] It is particularly advantageous if the upstream or downstream element should be fixed relative to the catalytic converter. A heating plate fixed with straight support pins inserted into the flow channel and permanently connected thereto can be positioned particularly easily relative to the catalytic converter.
[0022] A preferred exemplary embodiment is characterized in that in axial sections directly adjacent to one another, the throughflow directions of the respective flow channel sections with respect to the central axis are different.
[0023] The angle of the flow channel relative to the central axis is preferably between 1 and 15 degrees, particularly preferably between 1 and 10 degrees. The catalytic converter according to the invention preferably has a pore density of 600 to 1200 cpsi (pores per square inch).
[0024] It is also preferred that the length of the axial section along the central axis is between 5 mm and 50 mm.
[0025] The length of the axial section is preferably between 5 mm and 50 mm. The axial sections with straight flow channel sections extending parallel to the central axis on the inlet side and / or outlet side preferably have a length of 5 mm to 10 mm. The short length of these axial sections ensures that during the gluing and welding process, the solder also penetrates well into the subsequent axial section and thus produces a material-locking connection between the metal foils during the subsequent welding process.
[0026] The individual axial sections can additionally have special corrugations, wherein the largest or smallest corrugations are cut and a fold of the metal foil is provided in the opposite direction of the respective corrugation. This enables an overflow of the exhaust gas between mutually adjacent flow channels. In addition, an increase in the conversion rate of the catalytic converter can be achieved in this way, since the fold improves the gas flow, in particular makes it more turbulent. In particular in conjunction with a heating disk mounted on the catalytic converter, the folds are advantageous, since they enable a multi-point welded connection between the support pin and the catalytic converter.
[0027] The fold can be optionally arranged in an axial section with a flow channel extending parallel to the central axis and / or in an axial section with a flow channel arranged at an angle to the central axis. Particularly preferably, the fold is arranged in the area of the intake side, and particularly preferably, the axial starting point of the fold is arranged in the area 1 mm to 10 mm behind the intake side, particularly preferably in the area 1 mm to 5 mm.
[0028] Furthermore, it is advantageous if at least one metal foil has, in at least one axial section, a slot extending in the circumferential direction of the honeycomb body.
[0029] The slits are preferably already introduced into the metal foil before the corrugation process. The slits significantly reduce the material load during the corrugation process and thus reduce the risk of damage to the metal foil.
[0030] Another positive side effect of the slots extending in the circumferential direction in the wound honeycomb body is that the catalytic converter has an increased flexibility both in the axial direction and in the tangential direction, thereby avoiding the pore deformations that usually occur in continuous honeycomb bodies without slots due to thermal shocks. The slots can be arranged in the axial direction in straight axial sections or preferably at deflection points or transition points between axial channels with differently oriented flow channel sections.
[0031] It is also advantageous if the axial section adjacent to the intake side has a flow channel section extending parallel to the central axis, wherein the support pins are inserted into the individual flow channels and permanently connected to the honeycomb body. This makes it particularly easy to connect the heating disk to the catalytic converter.
[0032] It is also advantageous if the honeycomb body has, along its axial extent, alternating axial sections in which the flow direction is parallel to the central axis and axial sections in which the flow direction is at an angle to the central axis. This allows the radius at the deflection points or transitions between the axial sections to be increased in a targeted manner, thereby relieving the metal foil and therefore also the honeycomb body.
[0033] Furthermore, it is advantageous if the honeycomb body is formed from a plurality of metal foils stacked one on top of the other and which are wound around at least one rotation point.
[0034] It is also advantageous if the transition between two directly adjacent axial sections each represents a deflection point in the flow direction of the flow channel, thereby ensuring that the flow channel is not interrupted by the transition between the axial sections.
[0035] Advantageous developments of the invention are described in the dependent claims and in the following description of the figures. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The present invention will be described in detail below according to embodiments with reference to the accompanying drawings.
[0037] Figure 1 shows a sectional view of a catalytic converter having a honeycomb body according to the invention,
[0038] Figure 2 Detailed view showing a special shape of a corrugated foil, wherein the corrugations have a maximum corrugation area that is folded in opposite directions,
[0039] Figure 3 A sectional view of a catalytic converter is shown, wherein an auxiliary catalytic converter is shown, to which a heating disk is connected to the intake side by means of a supporting pin,
[0040] Figure 4A cross-sectional view showing the auxiliary catalytic converter and the heating disk, together with an alternative design of the continuous axial region,
[0041] Figure 5 A catalytic converter is shown in section, wherein the honeycomb body has slots extending in the circumferential direction within individual axial sections, and
[0042] Figure 6 The catalytic converter is shown in section, wherein the honeycomb body has slots extending in the circumferential direction at the transitions between adjacent axial sections. DETAILED DESCRIPTION
[0043] Figure 1 A catalytic converter 1 is shown, in which a honeycomb body 2 is accommodated in a casing 3. The honeycomb body has a plurality of axial sections 4, 5 through which exhaust gas can flow from an inlet side 6 to an outlet side 7.
[0044] exist Figure 1 In the embodiment of FIG. 5 , an axial section 5 having a flow channel section arranged at an angle to the central axis and an axial section 6 having a flow channel section extending parallel to the central axis are alternately shown. The axial section 5 alternately has a positive angle of attack to the central axis and a negative angle of attack to the central axis, whereby in Figure 1 In the cross-sectional view of FIG. 2 , an up-and-down movement of the flow channel occurs along the axial extension direction of the honeycomb body 2 .
[0045] Figure 2 A perspective view of a corrugated metal foil 8 is shown, wherein the largest corrugations protruding upwards have folds 9 which are folded out from the corrugations in opposite directions. Figure 2 In the embodiment of FIG. 1 , the folded area 9 itself has corrugations that are smaller than the main corrugations.
[0046] Figure 3 An alternative embodiment of a honeycomb body 2 is shown. On the gas inlet side, a heating disk 12 is arranged upstream of the honeycomb body and is connected to the honeycomb body via supporting pins 11 .
[0047] The honeycomb body 5 has, on its gas inlet side and gas outlet side, an axial section 4 with a flow channel section extending parallel to the central axis. The rest of the honeycomb body 2 is formed by the axial sections 5 which each have a flow channel section arranged at an angle.
[0048] It can be seen that the axial section 4 has a significantly shorter axial extension on the inlet side and on the outlet side than the central axial section 5 .
[0049] Figure 4The honeycomb body 2 is shown with an upstream heating disk 12. The axial sections 4 and 5 are arranged alternately here, so that starting with the axial section 4, the axial section 5 follows, and so on, until the axial section 4 follows again on the gas outlet side. The flow channel formed in this way thus moves up and down along the axial extent of the honeycomb body.
[0050] Figure 5 Another alternative honeycomb body 2 is shown, in which the axial sections 5 and the axial sections 4 are again arranged alternately. The difference compared to the previous figures is that the axial sections 4 now have additional slots 13 extending in the circumferential direction of the honeycomb body 2. The slots 13 are arranged centrally in the axial section 4.
[0051] Figure 6 Shown as Figure 5 The honeycomb body 2 shown in FIG. Figure 5 In contrast, the slot 13 is now arranged directly in the transition between the axial regions 4 and 5 .
[0052] Different features of the individual exemplary embodiments may also be combined with one another.
[0053] Figures 1 to 6 The exemplary embodiments described in the drawings do not have a restrictive character in particular and serve to illustrate the concept of the invention.
[0054] List of reference numerals:
[0055] 1 Catalytic converter
[0056] 2 Honeycomb
[0057] 3 Casing
[0058] 4 Axial sections
[0059] 5 Axial section
[0060] 6 Intake side
[0061] 7 Exhaust side
[0062] 8. Metal foil
[0063] 9 Folding Department
[0064] 11 Support pin
[0065] 12 Heating plate
[0066] 13 Slot
Claims
1. A catalytic converter (1) for exhaust gas aftertreatment of an internal combustion engine, the catalytic converter comprising a honeycomb body (2) formed by winding at least one metal foil, wherein: The honeycomb body (2) has a central axis, which extends along the axial extension direction of the honeycomb body from an air inlet side (6) of the honeycomb body (2) toward an air outlet side (7) of the honeycomb body (2), and the honeycomb body (2) has a plurality of flow channels through which gas can flow from the air inlet side (6) toward the air outlet side (7) of the honeycomb body (2). It is characterized in that The honeycomb body (2) is divided along its axial extension direction, along which the central axis extends, into individual axial sections (4, 5), wherein the axial sections (4, 5) have flow channel sections which extend at different angles relative to the central axis.
2. The catalytic converter (1) according to claim 1, characterized in that Each flow channel has flow channel sections corresponding to the number of the axial sections (4, 5), and each flow channel section extends along one of the axial sections (4, 5).
3. Catalytic converter (1) according to any one of the preceding claims, characterized in that An axial section (4) of the flow channel section starting at the air inlet side (6) of the honeycomb body (2) extends parallel to the center axis of the honeycomb body (2), and / or an axial section (4) of the flow channel section ending at the air outlet side (7) of the honeycomb body (2) extends parallel to the center axis.
4. Catalytic converter (1) according to any one of the preceding claims, characterized in that In axial sections (4, 5) that are directly adjacent to one another, the flow directions of the respective flow channel sections are different relative to the central axis.
5. Catalytic converter (1) according to any one of the preceding claims, characterized in that The length of the axial sections (4, 5) along the central axis is between 5 mm and 50 mm.
6. Catalytic converter (1) according to any one of the preceding claims, characterized in that At least one metal foil has, in at least one axial section (4, 5), slots (13) extending in the circumferential direction of the honeycomb body (2).
7. Catalytic converter (1) according to any one of the preceding claims, characterized in that The axial section (4) adjoining the inlet side (6) has flow channel sections extending parallel to the central axis, wherein support pins (11) are inserted into individual flow channels and are permanently connected to the honeycomb body (2).
8. Catalytic converter (1) according to any one of the preceding claims, characterized in that The honeycomb body (2) has, along its axial extension, alternatingly axial sections (4) in which the flow direction is parallel to the central axis and axial sections (5) in which the flow direction is at an angle to the central axis.
9. Catalytic converter (1) according to any one of the preceding claims, characterized in that The honeycomb body (2) is formed by a plurality of metal foils stacked one above the other, and the plurality of metal foils are wound around at least one rotation point.
10. Catalytic converter (1) according to any one of the preceding claims, characterized in that The transition between two directly adjacent axial sections (4, 5) each represents a deflection point in the throughflow direction of the flow channel.