JP2006037782A - Manifold converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manifold converter relaxing interference of exhaust gas and securing torque in low and middle speed zone of an internal combustion engine by a structure capable of keeping a gap between a catalyst carrier and a bulkhead as small as possible in the manifold converter having the bulkhead dividing flow of exhaust gas in an upstream of the catalyst carrier or both of in the upstream and in a downstream. <P>SOLUTION: The manifold converter is provided with the bulkhead dividing a space in the upstream of the catalyst carrier into two and a stopper member for accurately positioning distance between the bulkhead and the catalyst carrier on a part of the bulkhead. Distance between the catalyst carrier and the bulkhead, and variation of the distance can be established smaller by positioning in such a manner that the stopper member provided on a case subassembly touches the bulkhead provided on a cone subassembly in this structure. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a catalytic converter for purifying components in exhaust gas of an internal combustion engine, and more particularly to a manifold converter of a type in which a catalyst carrier is provided in the vicinity of an exhaust manifold assembly.

  As a catalytic converter for an internal combustion engine, there is a so-called manifold converter in which an exhaust manifold and a catalyst carrier are integrated.

  In this manifold converter, since the exhaust gas emitted from the combustion chamber is immediately introduced to the catalyst carrier, the heat loss is small, the catalyst is warmed up quickly, and the exhaust gas purification performance during cold is high.

  The technique shown in FIG. 3 is of a single manifold converter type and is an example applied to an in-line four-cylinder internal combustion engine. In this prior art, the exhaust gas flow exhausted from each cylinder is introduced into one space upstream of the catalyst carrier, and the exhaust gas is purified by passing through the catalyst carrier. However, this conventional technique has a large pressure loss due to exhaust interference, and there is a case where the torque is remarkably reduced.

  FIG. 4 shows an example of a dual manifold converter type for an in-line 4-cylinder type, which has two catalyst carriers and divides the exhaust passage into two, thereby preventing pressure loss due to exhaust interference and pressure at the catalyst carrier part. Used in internal combustion engines that reduce loss and are characterized by relatively high output. However, since the dual manifold converter type has two catalyst carriers, the heat capacity is larger than that of the single manifold converter type, which is slightly disadvantageous in the exhaust gas purification performance immediately after the cold start.

  The semi-dual manifold converter type shown in FIG. 5 has a single catalyst carrier as well as a single manifold converter type that is advantageous in that the heat capacity is small, but also has the characteristics of a dual manifold converter type that is advantageous in terms of exhaust interference. It is.

  The thing of patent document 1 is known as a dual manifold converter of this type. Patent Document 1 discloses that exhaust gas is separated into two flow passages and circulates in the catalyst carrier, thereby reducing torque reduction due to exhaust interference and using one catalyst carrier, so that exhaust gas particularly during cold weather is used. Purifying ability can be secured.

  In this type of manifold converter, as shown in FIG. 5, a catalyst carrier 4 is accommodated in a case 16 so as to be buffered by a mat 17 intended to hold the catalyst. A collecting portion 15 is welded to the upstream side of the case 16 from the outside, and the collecting portion 15 includes a partition wall 3e for preventing exhaust interference. The partition wall 3e is fixed to the collecting portion 15 by welding, and a relatively large gap C1 is secured between the partition wall 3e and the catalyst carrier 4.

In the manifold converter having such a configuration, the exhaust gas from the upstream is guided to the case 16 in which the catalyst carrier 4 is accommodated while the passage cross-sectional area is increased from the collecting portion 15 and the partition wall 3e. The exhaust gas guided to the inside of the catalyst carrier 4 is purified by the catalyst supported on the catalyst carrier 4 and discharged downstream.
JP 2001-164937 A

  In the prior art, a relatively wide gap C1 is generated between the end face of the partition wall and the end face of the catalyst carrier. This is because the gap is set at the time of manufacturing in consideration of the dimensional variation of each part before welding, the welding variation between parts, etc., and the change of the gap due to the thermal expansion of the collecting portion 15 and the partition wall 3e, or the actual use This is because a sufficient gap is set so that there is no interference between the tip of the partition wall and the catalyst even if the position of the catalyst carrier changes due to cold heat, vibration, or the like. Therefore, by securing a sufficient gap at the time of manufacture, interference between the partition wall 3e in the gap and the catalyst carrier 4 can be avoided, and problems such as catalyst damage and noise can be avoided.

  As described above, the manifold converter having such a configuration is manufactured with a relatively wide gap C1 between the partition wall 3e and the catalyst carrier 4 due to its configuration. First, the catalyst carrier 4 is inserted into the case 16 at a predetermined position via the mat 17 to form a catalyst subassembly. Separately, a cone subassembly is manufactured by combining the partition wall 3e with the collecting portion 15 from the inside. Next, the catalyst subassembly and the cone subassembly are set on a jig, and both parts are welded from the outside of the assembly portion 15 to form a converter subassembly. Thereafter, each port, head flange, and brackets are welded or assembled to the converter subassembly to form a manifold converter.

  In the catalyst subassembly, when the mat 17 and the catalyst carrier 4 are assembled to the case 16, the positional variation between the case 16 and the catalyst carrier 4 is determined. In addition, in the cone subassembly, in addition to the dimensional variation of the collecting portion 15 and the partition wall 3e itself, if the collecting portion 15 and the partition wall are welded, the variation in the position of the partition wall tip with respect to the collecting portion 15 is determined by the welding variation. Is done. Next, when the converter sub-assembly is manufactured, the lower end of the cylinder of the catalyst sub-assembly and the lower end of the collecting portion of the cone sub-assembly are set as a reference, and both parts are welded.

  Accordingly, the gap between the partition wall 3e and the catalyst carrier 4 cannot be directly managed when the converter subassembly is manufactured. That is, in order to prevent damage to the catalyst due to interference between the partition walls and the catalyst, it is necessary to set a sufficiently wide gap C1 in consideration of these variations.

  Similarly, in the gathering portion on the downstream side of the catalyst carrier, if the specification is provided with the partition walls 3f, it is necessary to set a sufficiently wide gap as described above.

  However, in the above conventional technique, there is a large amount of exhaust gas leakage between the partition walls and the catalyst carrier, and the function of preventing exhaust interference is reduced, which may hinder the improvement of torque of the internal combustion engine.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a manifold converter structure capable of improving torque by reducing exhaust interference.

A manifold converter according to the present invention includes a catalyst carrier, a case for housing the catalyst carrier, a collecting portion to which an exhaust manifold of each cylinder of the internal combustion engine is connected, and a partition wall provided in the collecting portion for separating the exhaust gas. And a stopper member inserted so as to be in contact with the end of the partition wall and the end surface of the catalyst carrier to indirectly contact the end portion of the partition wall and the end surface of the catalyst carrier to thereby define the distance between the partition wall and the catalyst carrier. The gap is extremely small and the variation is small.

  A manifold converter according to a first aspect of the present invention includes a catalyst carrier, a case for housing the catalyst carrier, a collecting portion to which the exhaust manifold of each cylinder of the internal combustion engine is connected, and a continuous explosion cylinder provided in the collecting portion. An upstream partition that separates exhaust gas from the catalyst and guides it to the catalyst carrier, and an upstream stopper member is inserted into at least a portion between the downstream end of the upstream partition and the upstream end surface of the catalyst carrier Composed.

  In addition to the first invention, the manifold converter according to the second invention has a downstream partition so that the exhaust gas divided by the upstream partition upstream of the catalyst support is separated as it is also downstream of the catalyst support, Furthermore, a downstream stopper member is provided between the outlet surface of the catalyst carrier and the upstream end of the downstream partition. Similar to the first aspect of the invention, the downstream stopper member is disposed so as to contact the downstream end surface of the catalyst carrier interposed in the case, and the downstream stopper member is bonded to the downstream collecting portion. It is arrange | positioned so that the made partition may be touched.

  The stopper member is composed of a cushion material and a guide member in the third invention, and is composed of a cushion material in the fourth invention.

A manifold converter according to a third aspect of the present invention includes a cushion member disposed so as to be in contact between the catalyst carrier and the partition wall as a stopper member, and a guide fixed to the inner peripheral surface of the case for fixing the cushion material. A member.
The stopper member of the manifold converter according to the fourth aspect of the present invention is a cushion member that is disposed so as to be in contact with the catalyst carrier and the partition wall and is fixed to the inner peripheral surface of the case.

  In the manifold converter according to the fifth aspect of the present invention, the stopper member is interposed during the manufacture to accurately determine the space between the end of the partition wall and the end face of the catalyst carrier, and then burned down by the high-temperature exhaust gas due to the actual operation of the internal combustion engine. It is comprised with the material to do or a wire mesh-like material.

  A manifold converter according to a sixth aspect of the present invention has a cone subassembly in which the collecting portion and the partition wall are fixed, and a catalyst subassembly in which the case and the catalyst carrier are fixed, and between the end portion of the partition wall and the end surface of the catalyst carrier. A stopper member is provided so as to contact.

  According to the first invention, it is necessary to set a gap in consideration of the dimensional variation of each part before welding in the conventional manufacturing method, the variation in the fitting position of the case and the catalyst carrier, and the welding variation between the parts. It can be manufactured without. As a result, the gap between the partition walls and the catalyst carrier can be reduced, and the communication of exhaust gas from the gap can be minimized.

  Therefore, according to the first invention, the influence of the exhaust interference up to the outlet of the catalyst carrier can be reduced, and the torque can be improved.

  According to the second invention, the gap between the outlet surface of the catalyst carrier and the downstream partition can be set small, and exhaust interference can be suppressed at least to the position where the downstream partition ends. In this case, since the partition wall that can prevent the exhaust interference is disposed longer than the first invention, the torque can be further improved.

  According to the third aspect of the invention, the cushion material is in contact with the partition wall end and the catalyst carrier, thereby accurately positioning the space between the partition wall and the catalyst carrier. Thereby, the gap between the partition wall and the catalyst carrier can be set small, and the exhaust interference is reduced, so that the torque can be improved. Further, since the cushion material is fixed by the guide member, the cushion material does not fall or shift when the catalyst subassembly and the cone subassembly are welded, and the productivity is excellent. Further, when the catalyst subassembly and the cone subassembly are joined, it also acts as a buffer material when the partition wall and the catalyst carrier are accidentally bumped to protect the catalyst carrier.

  According to the fourth invention, similarly to the third invention, the gap between the partition wall and the catalyst carrier can be set small, and the exhaust interference is reduced, so that the torque can be improved. The cushion material may be fixed to the case with a tension or bonded to the case, and the above effect can be obtained by combining the support member with a partition wall that has been joined to the gathering portion in advance. Will be obtained. In this case, since it becomes a comparatively simple component structure, low-cost production is possible.

  According to the fifth invention, as in the third and fourth inventions, the gap between the partition walls and the catalyst carrier can be set small, and exhaust interference is reduced, so that torque can be improved. In addition, since the stopper member is burned out due to the actual operation of the internal combustion engine, the exhaust gas inflow into the hole of the catalyst carrier at the portion where the stopper member and the catalyst carrier overlap can be expected more than the first to fourth inventions. High torque and excellent catalyst purification capacity. In addition, if the stopper member is made of a material obtained by molding a wire mesh, it is possible to divert the material widely used for the gasket of the exhaust system from the beginning, and the development is relatively simple.

  According to the sixth aspect of the invention, the stopper member is inserted between the case subassembly and the catalyst subassembly, and is positioned when the case subassembly and the catalyst subassembly are joined. Therefore, the interval between the partition walls and the catalyst carrier can be set small, and the variation can be set small. Thereby, exhaust interference can be reduced and torque can be improved.

  As described above, the gap between the partition wall and the catalyst is determined only by the thickness of the stopper member at the time of manufacture and the dimensional tolerance of the partition wall, and a dual type manifold converter having a partition wall with the minimum clearance that has been difficult to mass-produce in the past can be realized. .

  An embodiment in which the present invention is used in an exhaust system of an automotive four-cylinder internal combustion engine will be described with reference to FIG.

  FIG. 6 is a schematic diagram showing an automobile 1 on which the catalytic converter according to the embodiment of the present invention is mounted, its internal combustion engine 2, and each part of the exhaust system of the internal combustion engine 2. In FIG. 6, a manifold converter 3 is provided in the exhaust system of the internal combustion engine 2 mounted on the automobile 1. The manifold converter 3 includes a catalyst carrier 4 as one of the catalytic converters. The catalyst carrier 4 is for quickly purifying components in the exhaust gas discharged from the internal combustion engine 2 immediately after the cold start of the internal combustion engine 2. Generally, in order for a catalytic converter to function, it needs to be warmed above a predetermined temperature. The catalyst carrier 4 is disposed in the vicinity of the internal combustion engine 2 so as to be warmed up by the exhaust gas as soon as possible.

  A main converter 9, which is another catalytic converter, is connected to the downstream side of the manifold converter 3 via an exhaust pipe 8. The main converter 9 is for purifying most of exhaust gas components discharged from the internal combustion engine 2 when the internal combustion engine 2 is warm.

  A sub-muffler 11 is connected to the downstream side of the main converter 9 via an exhaust pipe 10. Further, a main muffler 13 is connected to the downstream side of the sub muffler 11 via an exhaust pipe 12. Both the mufflers 11 and 13 are for canceling and absorbing the pressure of the exhaust gas, and quieting the sound emitted outside or inside the vehicle.

  A tail pipe 14 is connected to the downstream side of the main muffler 13.

  In the exhaust system configured as described above, exhaust gas discharged from the internal combustion engine 2 is supplied from the manifold converter 3, the exhaust pipe 8, the main converter 9, the exhaust pipe 10, the sub muffler 11, the exhaust pipe 12, the main muffler 13, and the like. It flows through the tail pipe 14 and is discharged to the outside. The exhaust gas flowing in this manner is purified by the manifold converter 3 and the main converter 9 and is silenced by the sub-muffler 11 and the main muffler 13.

  Next, the manifold converter 3 and its peripheral structure will be described with reference to FIG. On the upstream side of the catalyst carrier 4, four cylinders # 1, # 2, # 3, and # 4 are formed to be connected to each other corresponding to the branch pipes 3 a, 3 b, 3 c, and 3 d, respectively. These branch pipes are close to the catalyst carrier 4 and 3a and 3d communicate with each other and are opened to one exhaust passage E1. On the other hand, the branch pipes 3b and 3c are also communicated with each other at a portion close to the catalyst carrier 4 and opened to the exhaust passage E2. The exhaust passages E1 and E2 are adjacent to each other and integrated, and the appearance is formed in a cone or a cylindrical shape. Between the exhaust passages E1 and E2 adjacent to each other, the exhaust passages E1 and E2 are formed by being divided into two by the upstream partition 3e. That is, the branch pipes 3a and 3d communicate with the exhaust passage E2, and the branch pipes 3b and 3c communicate with the exhaust passage E1. The reason why the exhaust gas path is divided into groups of two cylinders in this way is to exhaust the exhaust gas efficiently. In the case of the in-line four-cylinder internal combustion engine of this embodiment, the ignition order is # 1- # 3- # 4- # 2- # 1. In order to efficiently exhaust the exhaust gas, a group is formed by combining the cylinders (# 1- # 4 and # 2- # 3) that exhaust the exhaust gas at timings where the ignition order is not adjacent to each other. The mutual interference of gas is reduced.

  Although the catalyst carrier 4 is disposed on the downstream side, there is a predetermined gap (C1 in FIG. 5) between the upstream partition wall 3e and the catalyst carrier 4, and dimensional variations and welding of each part during production. The gap is set so that there is no interference between the upstream partition 3e and the catalyst carrier 4 due to variations, thermal expansion of components due to high-temperature exhaust gas, vibration of the internal combustion engine, and the like. However, if the gap is large, the amount of communication between the exhaust passage E1 and the exhaust passage E2 increases, and the low / medium speed torque decreases due to the influence of exhaust interference. Therefore, it is necessary to make the gap as small as possible.

  Next, the holding of the catalyst carrier 4 in the case 16 will be described. The catalyst carrier 4 is held in a form buffered by a mat 17 made of alumina fiber, for example. The catalyst carrier 4 has a honeycomb structure in the radial direction, and does not propagate pressure in the radial direction of the catalyst carrier 4 during the exhaust gas flow passing through the catalyst carrier 4. Since the exhaust gas flowing through the catalyst carrier 4 flows for each of the holes, the exhaust gas largely divided into two by the upstream partition wall 3e is divided until it passes through the catalyst carrier 4.

  FIG. 1 shows a mode in which the exhaust passage F1 on the downstream side does not divide the exhaust path. In this case, the branch of the exhaust path ends at the outlet of the catalyst carrier 4. FIG. 2 shows a mode in which the downstream side of the catalyst carrier 4 is branched to the downstream side exhaust passage F2 and the exhaust side passage F3 by the downstream side partition wall 3f. This is because the combined exhaust gas divided by the downstream partition 3f becomes the downstream end of the downstream partition 3f, and the split exhaust gas is separated from the mode in which the outlet of the catalyst carrier 4 in FIG. Since the path to the merging is long, the exhaust interference can be further reduced, and the torque in the low and medium speed rotation range of the internal combustion engine can be further increased. Depending on the specifications, a partition plate (not shown) that divides the exhaust gas is set inside the exhaust pipe that continues further, and in that case, exhaust interference can be further reduced.

  Next, the partition wall 3e will be described with reference to FIGS. FIG. 7 shows an example in which the distance C2 between the tip of the partition wall 3e and the catalyst carrier 4 is set using the cushion material 5 and the guide member 6, and FIG. 8 shows a central sectional view thereof. The upstream partition 3e is welded to the inside of the upstream cone 15 to prevent the exhaust gas from communicating between the exhaust passages E1 and E2. A portion of the partition wall 3e close to the case has a cutout shape 18 for avoiding the cushion material 5, and is in contact with the cushion material 5 in the exhaust gas flow direction. Further, the opposite surface of the cushion material 5 in contact with the partition wall 3e is in contact with the exhaust gas inlet surface of the catalyst carrier, and the cushion material 5 is in contact with the inlet surface of the catalyst carrier by the guide member 6. It is fixed.

  In the present embodiment in FIG. 7, first, the mat 17 is aligned with the case 16, and the cushion material 5 is aligned with the end surface of the catalyst carrier 4 in the catalyst subassembly in which the catalyst carrier 4 is disposed at a predetermined position. It fixes with the guide member 6 so that a position may not shift | deviate. On the other hand, the cone subassembly in which the collecting portion 15 and the partition wall 3e are welded is set to cover the catalyst subassembly. At that time, the partition 16 is fixed to the jig while being positioned so that the tip of the partition wall 3e is in contact with the cushion material 5, and the case 16 and the collecting portion 15 are welded. In the present embodiment, there is no need to calculate in advance the design gap due to variations in the arrangement position of the case 16 and the catalyst carrier 4, welding variations between the partition walls 3e and the collecting portion 15, dimensional variations in the partition walls 3e, and the like. Since the gap 4 is dominated by the dimensional variation of the spacer 5, it is possible to produce with a very small gap C2 of about 0.5 mm.

  According to the present embodiment, since the distance between the partition wall 3e and the catalyst carrier 4 can be made extremely small, the influence of exhaust interference can be reduced and the torque of the internal combustion engine can be improved.

  In the embodiment of FIGS. 9 to 10, the stopper member 7 is used to set the distance C2 between the tip of the partition wall 3e and the catalyst carrier 4, and FIG. 10 shows a central sectional view thereof. In this case, the stopper member 7 may be made of a non-metallic component such as ceramic. Alternatively, a wire mesh metal may be used. The stopper member 7 is fixed to the inner surface of the case 16 without using a guide member so as to contact the end surface of the catalyst carrier 4 disposed in the case 16. In this case, the fixing method may be press-fitting, welding, or adhesion. Moreover, the thing of C ring shape urged | biased by the outer peripheral side with respect to the internal peripheral surface of a case may be sufficient. Set in a form that covers the corn subassembly. At that time, the case 17 and the collecting portion 15 are welded while being fixed so that the tip of the partition wall 3e is in contact with the stopper member 7.

  According to the present embodiment, as in the embodiment using the guide member 6, the distance can be made extremely small, and the influence of exhaust interference can be reduced.

  This embodiment shown in FIGS. 9 to 10 is an example in which the stopper member 7 is set over the entire circumference of the catalyst carrier, and in this case, the exhaust gas does not directly hit the mat 17. . Thereby, since the mat 17 is not exposed to the exhaust gas having a high temperature or a high back pressure, the wind erosion of the mat 17 can be prevented. Further, deterioration of the mat material can be suppressed, which is advantageous from the viewpoint of catalyst retention. The stopper member 7 prevents the short fibers from protruding from the side surface of the mat 17, so that the cylinder bore scuffing due to the reverse flow of the short fibers, which is rarely seen in a new state, can be prevented.

  After the function of determining the relative positions of the catalyst subassembly and the cone subassembly is used at the time of manufacture, the stopper member 7 may be burned out by the heat generated by the internal combustion engine or the wire mesh may be formed. The material (for example, resin) filled in the space of the wire mesh may be burned down by actual operation of the internal combustion engine.

  Further, if the stopper member 7 is provided only in the partition wall, the gap between the partition wall 3e and the catalyst carrier 4 can be obtained, and therefore it is not necessary to exist over the entire circumference, It may be set only on one side of the contact portion. In this case or the type in which the stopper member 7 is burned out, the number of portions covering the catalyst carrier by the stopper member 7 can be set to be small.

Explanatory drawing of the exhaust manifold structure of the internal combustion engine of this Embodiment. Explanatory drawing of the exhaust manifold structure of the internal combustion engine of this Embodiment. Explanatory drawing of the exhaust manifold structure which employ | adopted the conventional single manifold converter. Explanatory drawing of the exhaust manifold structure which employ | adopted the conventional dual manifold converter. Explanatory drawing of the exhaust manifold structure which employ | adopted the conventional semi-dual manifold converter. 1 is a schematic diagram showing an outline of an internal combustion engine and an exhaust system to which an exhaust manifold of the present embodiment is applied. Sectional drawing which shows the partially expanded structure of embodiment of the exhaust manifold which concerns on this invention. Sectional drawing in the cutting line shown in FIG. Sectional drawing which shows the partially expanded structure of embodiment of the exhaust manifold which concerns on this invention. Sectional drawing in the cutting line shown in FIG.

Explanation of symbols

2 Internal combustion engine 3 Manifold converter 4 Catalyst carrier 5 Cushion material 6 Guide member 7 Stopper member 15 Collecting part 16 Case 17 Mat 18 Notch shape 3e Upstream partition 3f Downstream partition

Claims (6)

In a manifold converter that purifies by collecting exhaust manifolds of an internal combustion engine having a plurality of cylinders on the exhaust downstream side and passing exhaust gas,
A catalyst support;
A case for accommodating the catalyst carrier;
An upstream assembly to which an exhaust manifold of each cylinder of the internal combustion engine and the case is connected;
An upstream partition that is provided in the upstream assembly and separates exhaust gas from successive explosion cylinders and guides it to the catalyst carrier;
A manifold converter comprising an upstream stopper member inserted into at least a part between an end portion of the upstream partition wall and an end surface of the catalyst carrier. The manifold converter according to claim 1, wherein the manifold converter is connected to the case, and a downstream partition wall provided in the downstream assembly portion and disposed in parallel with the upstream partition wall;
A manifold converter comprising a downstream stopper member inserted into at least a part between an upstream end portion of the downstream partition wall and a downstream end surface of the catalyst carrier. 3. The manifold converter according to claim 1, wherein the upstream stopper member and the downstream stopper member are cushion members disposed so as to be in contact with the catalyst carrier and the partition wall;
A manifold converter comprising a guide member fixed to the inner peripheral surface of the case for fixing the cushion material.   3. The manifold converter according to claim 1, wherein the upstream side stopper member and the downstream side stopper member are disposed so as to be in contact with each other between the catalyst carrier and the partition wall, and are made of a cushion material fixed to the inner peripheral surface of the case. Manifold converter characterized by that.   5. The manifold converter according to claim 1, wherein the stopper member is made of a material burned by heat of exhaust gas or a wire mesh material. In a manifold converter that purifies by collecting exhaust manifolds of an internal combustion engine having a plurality of cylinders on the exhaust downstream side and passing exhaust gas,
A cone subassembly in which the collecting portion and the partition are fixed;
A catalyst subassembly in which a case and a catalyst carrier are fixed;
A manifold converter comprising a stopper member inserted into at least a part between an end portion of the partition wall and an end surface of the catalyst carrier.

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