JP2016094942A - Exhaust emission control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of preventing exhaust gas from contacting with a mat.SOLUTION: A case 20 has: a general part 21 wound around the outer periphery of a mat 12; a vertical wall 22 curved substantially vertically from end part 21a of the general part 21 toward an axial line CL of the case 20, and a diameter reduction part 23 whose diameter is reduced from an end part 22a on the axial line CL side of the vertical wall 22. The vertical wall 22 is formed so as to separate from a purification member 11, and a line L1 parallelly extending from the tip of the vertical wall 22 to the axial line CL contacts with the purification member 11. The diameter reduction part 23 has such a shape that a curvature radius continuously varies, and a tangent line L2 of the diameter reduction part 23 in the end part 22a on the vertical wall 22 side contacts with the purification member 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an exhaust gas purification apparatus.

  In order to purify the exhaust gas discharged from the engine, many vehicles are equipped with an exhaust gas purification device (see, for example, Patent Document 1 (FIG. 2)).

  As shown in FIG. 7, the exhaust gas purification apparatus 100 includes a ceramic catalyst carrier 101 carrying a catalyst, a mat 102 wound around the outer peripheral surface of the catalyst carrier 101, the catalyst carrier 101, It consists of a metal case 103 in which a mat 102 is accommodated. The diameter of the case 103 is reduced so that the case 103 can be connected to the pipe member 105. A method of forming the case 103 in such a shape will be described with reference to the next drawing.

  As shown in FIG. 8, the upstream side of the case 103 can be reduced in diameter by spinning. The spinning process is performed in a state where the downstream side of the case 103 is suppressed by the clampers 111 and 111. As indicated by the arrow (1), the spinning rollers 112 and 112 are brought into contact with the outer periphery of the case 103 while rotating the plurality of spinning rollers 112 and 112. By contacting, the case 103 is plastically deformed by the pressing force. According to the spinning process, the case 103 can be created from a cylindrical case material. It is not necessary to weld other parts to create the case 103, and the case 103 can be created with a small number of parts.

  Returning to FIG. 7, by operating the internal combustion engine, the exhaust gas is caused to flow inside the exhaust gas purifying device 100 as indicated by the arrow (2). Most of the exhaust gas is purified toward the catalyst carrier 101 as indicated by the arrow (3). However, as shown by the arrow (4), a part of the exhaust gas flows along the tapered portion 103a of the case 103 and contacts the mat 102. The exhaust gas is a high-temperature gas. From the viewpoint of extending the life of the mat 102, it is desired to suppress contact of hot exhaust gas with the mat 102.

JP 2003-120275 A

  This invention makes it a subject to provide the technique which can suppress that exhaust gas contacts a mat | matte.

According to the first aspect of the present invention, in the exhaust gas purification apparatus comprising the purification member, the mat wound around the purification member, and the cylindrical case that houses the purification member and the mat,
The case includes a general part wound around the outer periphery of the mat, a vertical wall bent substantially perpendicularly toward an axis of the case from an end of the general part, and the axial side of the vertical wall. A reduced diameter portion that is reduced in diameter from the end portion,
The vertical wall is formed apart from the purification member,
A line extending in parallel to the axis from the tip of the vertical wall contacts the purification member,
The reduced diameter portion has a shape in which the radius of curvature continuously changes,
An exhaust gas purification apparatus is provided in which a tangent line at an end of the reduced diameter portion on the vertical wall side is in contact with the purification member.

According to the invention according to claim 2, in the exhaust gas purification apparatus comprising a purification member, a mat wound around the purification member, and a cylindrical case that houses the purification member and the mat,
The case includes a general part wound around the outer periphery of the mat, a vertical wall bent substantially perpendicularly toward an axis of the case from an end of the general part, and the axial side of the vertical wall. A reduced diameter portion that is reduced in diameter from the end portion,
The vertical wall is formed apart from the purification member,
A line extending in parallel to the axis from the tip of the vertical wall contacts the purification member,
An exhaust gas purification apparatus is provided in which an extension line extending from an end of the reduced diameter portion on the vertical wall side is in contact with the purification member.

  As described in claim 3, it preferably has an uneven portion formed in an uneven shape.

  In the present invention, the line extending in parallel to the axis from the tip of the vertical wall contacts the purification member. That is, the end of the vertical wall on the axial line side extends to a position overlapping the mat in a cross-sectional view when the flow direction of the exhaust gas is used as a reference. This can further suppress the exhaust gas from flowing toward the mat.

  In the invention which concerns on Claim 1, the tangent in the edge part by the side of the vertical wall of a reduced diameter part is contacting the purification | cleaning member. The reduced diameter portion has a so-called composite r shape in which arc shapes having different curvature radii are continuously formed. When a tangent line is extended from a point in the inner peripheral surface of the reduced diameter portion near the end of the vertical wall on the axis line side, the tangent line contacts the purification member before contacting the mat. The exhaust gas flowing along the inner peripheral surface can be more reliably guided toward the purification member. By guiding to the purification member, it is possible to suppress the exhaust gas from contacting the mat.

  In the invention which concerns on Claim 2, the extended line extended from the edge part by the side of the vertical wall of a diameter reduction part is contacting the purification | cleaning member. The extension line of the reduced diameter portion contacts the purification member before the mat. As a result, the exhaust gas can be more reliably guided to the purification member.

1 is a cross-sectional view of an exhaust gas purification apparatus according to Embodiment 1. FIG. It is a figure explaining the process from the process of preparing the catalyst carrier on which the case material and the mat are wound to the compression process of the case material. It is a figure explaining from a diameter reduction process to a vertical wall shape process. It is a figure explaining a finishing process. It is a figure which compares the case where a vertical wall is formed after performing a diameter reduction process, and the case where a vertical wall is formed without performing a diameter reduction process. It is sectional drawing of the exhaust gas purification apparatus by Example 2. FIG. It is sectional drawing of the exhaust gas purification apparatus by a conventional example. It is a figure explaining the shaping | molding method of the case shown by FIG.

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
<Example 1>

First, Embodiment 1 of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the catalyst device 10 (exhaust gas purification device 10) includes a ceramic catalyst carrier 11 (purification member 11), a mat 12 wound around the catalyst carrier 11, and these catalyst carriers 11. And a metal case 20 for housing the mat 12.

  In addition to the catalyst carrier 11, a diesel particulate filter (Diesel Particulate Filter) can be adopted as the purification member. Furthermore, the catalyst carrier 11 includes a catalyst carrier for all uses such as for diesel engines and gasoline engines. That is, the purification member is not limited to these as long as it is used for the purpose of purifying exhaust gas generated in the internal combustion engine.

  As the mat 12, a mat containing alumina fibers can be used. The mat 12 can be wound around the catalyst carrier 11 by a mat winding device in addition to manual winding by an operator.

  The mat 12 may be any mat including metal fibers other than alumina fibers and ceramic fibers, paper mats, mats containing vermiculite, needles, glass fibers, and the like.

  The case 20 includes a general portion 21 wound around the outer periphery of the mat 12, and a vertical wall 22 bent substantially perpendicularly from the upstream end portion 21a of the general portion 21 toward the axis CL of the case 20, A reduced diameter portion 23 whose diameter is reduced toward the upstream from the end portion 22a on the axis line CL side of the vertical wall 22 is connected to a pipe member 31 indicated by an imaginary line at the distal end of the reduced diameter portion 23 so that the exhaust gas flows. And an exhaust gas inlet 24 to be introduced.

  By forming the vertical wall 22, it is possible to suppress the exhaust gas from being guided to the mat 12 along the wall surface of the case 20. That is, the contact of the exhaust gas with the mat 12 is suppressed. By suppressing the high temperature exhaust gas from coming into contact with the mat 12, the life of the catalyst device 10 can be extended.

  The end 22a on the axis CL side of the vertical wall 22 extends to a position overlapping the mat 12 in a cross-sectional view when the exhaust gas flow direction is used as a reference (see the imaginary line L1). As a result, the exhaust gas can be further suppressed from flowing toward the mat 12.

  The reduced diameter portion 23 has a so-called composite r shape in which arc shapes having different curvature radii are continuously formed. When the tangent line L2 is extended from a point near the end 22a on the axis line CL side of the vertical wall 22 in the inner peripheral surface 23b of the reduced diameter part 23, the tangent line L2 is the catalyst before contacting the mat 12. Contact the carrier 11. The exhaust gas flowing along the inner peripheral surface 23b can be more reliably guided toward the catalyst carrier 11. By guiding to the catalyst carrier 11, it is possible to suppress the exhaust gas from contacting the mat 12.

  The reduced diameter portion 23 is formed by a spinning process, and has a concavo-convex part 23c formed in a concavo-convex shape when the spinning process is performed. On the other hand, the inner peripheral surface 22c in the vicinity of the vertical wall 22 is formed in a flat surface shape. Since the inner peripheral surface 22c of the vertical wall 22 in the vicinity of the mat 12 is formed in a flat surface shape, the exhaust gas can flow smoothly toward the catalyst carrier 11.

  In addition, it is also possible to spin the end portion on the downstream side of the case 20 similarly to the upstream side. Moreover, the cone part which diameter-reduces toward a downstream can also be joined to the downstream edge part, and arbitrary structures can be employ | adopted for it.

In addition, the exhaust gas inlet 24 can be configured to connect the pipe member 31 via a flange.
Next, details of the manufacturing method of the catalyst device 10 will be described in the following figures.

  As shown in FIG. 2A, first, a catalyst carrier 11 around which a mat 12 is wound and a cylindrical case material 41 serving as a material of a case (FIG. 1, reference numeral 20) are prepared. When these are prepared, the catalyst carrier 11 around which the mat 12 is wound is inserted into the case material 41.

  Next, as shown in FIG. 2B, the case material 41 is compressed and plastically deformed by the compression pieces 51, 51 of the compression device 50 until the outer diameter becomes D <b> 1. When the compression pieces 51, 51 are removed, a semi-finished product 40 as shown in FIG. 2C can be obtained.

  When the compression pieces 51, 51 are removed, the case material 41 slightly returns (this phenomenon is referred to as springback), and the semi-finished product 40 has a slightly larger outer diameter D2. That is, the outer diameter of the case material 41 before being removed from the compression device 50 is D1, and the outer diameter of the semi-finished product 40 after being removed from the compression device 50 is D2.

  The storing step of storing the catalyst carrier 11 around which the mat 12 is wound in the case material 41 may be performed after the case material 41 is formed. Therefore, the compression step of compressing the case material 41 in a state where the catalyst carrier 11 is stored, which is performed after the storage step, can also be performed after the case material 41 is formed.

  When the storing step and the compression process are performed before the case material 41 is formed, the end portion on the downstream side of the case material 41 can also be subjected to spinning processing. In the following drawings, the forming of the case material 41 will be described.

  As shown in FIG. 3A, a portion 41a of the case material 41 corresponding to the end 11a of the catalyst carrier 11 to one end 41b of the case material 41 is continuously compressed by a spinning roller 60. Diameter. This is the diameter reduction process. What is indicated by an imaginary line is the shape of the case material 41 after the diameter reduction.

  The diameter reduction step is performed by repeating the passes as shown by arrows (11) to (14). A path indicated by the arrow (11) from the catalyst carrier 11 toward the one end 41b of the case material 41 is referred to as an outward path. A path indicated by the arrow (12) from the one end 41b of the case material 41 toward the catalyst carrier 11 is referred to as a return path. A path following the tapered surface 71 indicated by the arrows (13) and (14) is referred to as a lamination path.

  After forming in the order of arrows (11) to (14), next, forming is performed in the order of arrows (15) to (18). Such processing is repeated toward the one end 41 b of the case material 41. Spinning is performed leaving a portion corresponding to the exhaust gas inlet (FIG. 1, reference numeral 24).

  In the path (arrows (11), (14), (15), (18)) from the catalyst carrier 11 toward the one end 41b of the case material 41, the plate thickness of the case material 41 tends to be thin. On the other hand, in the path (arrows (12), (13), (16), (17)) from the one end 41b of the case material 41 to the catalyst carrier 11, the plate thickness of the case material 41 is not easily reduced. In the present invention, in addition to these passes, the case (FIG. 1, reference numeral 20) is formed by a reduced diameter pass, which will be described later.

  The tapered surface 71 of the case material 41 that is inclined with respect to the axis CL by the diameter reduction process is preferably inclined at 20 ° to 35 ° with respect to the axis CL. That is, it is desirable that θ = 20 ° to 35 °.

  Next, as shown in FIG. 3B, main forming (vertical wall formation) for forming the reduced diameter portion 23 and the vertical wall 22 is performed. This process is called a main forming process (vertical wall forming process). In contrast to the main forming step shown in FIG. 3 (b), the diameter reducing step shown in FIG. 3 (a) can also be referred to as a pre-forming step.

  The main forming step is performed by a return path as indicated by arrows (21) and (22). The vertical wall 22 is formed so as to connect the step between the general portion 21 and the reduced diameter portion 23. That is, by the main forming process (vertical wall forming process), the axis CL (shown in FIG. 1) of the case material 41 using the roller 60 in the portion 41 a corresponding to the end portion 11 a of the catalyst carrier 11 in the case material 41. The vertical wall 22 is formed toward the axis CL of the case.

  As shown in FIG. 4, the vertical wall 22 is raised substantially perpendicular to the axis line CL. This process is called a finishing process. The finishing process is performed by pressing the side surface 60a of the roller 60 against the vertical wall 22 as indicated by the arrow (31). In this way, the catalyst device is completed. The reason why the diameter reduction process is performed prior to the formation of the vertical wall 22 will be described with reference to the following figure.

  FIG. 5A schematically shows the case 80. The inventors have formed the vertical wall 82 directly from the edge of the general portion 81 (hereinafter referred to as “comparative example”), and the case where the vertical wall 82 is formed after being formed into a tapered shape (hereinafter referred to as “comparative example”). The difference in thickness from that of “Examples”) was measured. The measurement was performed from the portion corresponding to the end portion 86 a of the catalyst carrier 86 to the tip of the case 80. That is, the part corresponding to the end 86a of the catalyst carrier 86 is the measurement start point, and the tip of the case 80 is the measurement end point.

  FIG. 5B shows the measurement result. The horizontal axis is the length from the measurement start point, and the vertical axis is the case plate thickness. The result of the example is indicated by a solid line, and the result of the comparative example is indicated by a one-dot chain line.

  Referring also to FIG. 5A, the case according to the comparative example has a thickness that is abruptly reduced in the vertical wall (see P1). In such a part, since the plate thickness is thin, the case is easily broken. Moreover, stress is easy to concentrate because only a part is thin.

On the other hand, in the case according to the example, there is no portion where the plate thickness changes abruptly, and the plate thickness is constant throughout as compared with the case according to the comparative example. By making the plate thickness constant, the occurrence of defective products can be suppressed. Further, the life of the case can be extended by eliminating the portion where the stress is concentrated.
<Example 2>

Next, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 6 shows a cross-sectional configuration of the catalyst device of the second embodiment, corresponding to FIG.
As shown in FIG. 6, in the catalyst device 10A, the reduced diameter portion 23A of the case 20A is linearly formed. Also according to the catalyst device 10A, the predetermined effect of the present invention can be obtained.

  When the diameter-reduced portion 23A is linear, it is desirable that the extension line L2A of the diameter-reduced portion 23A comes into contact with the catalyst carrier 11 before the mat 12. As a result, the exhaust gas can be more reliably guided to the catalyst carrier 11.

  Furthermore, the vertical wall 22 may form only the vertical wall 22 after the diameter reducing step, or may form the vertical wall 22 while forming the linear reduced diameter portion 23A by the main forming.

  Although the purification device of the present invention has been described based on an example applied to a four-wheeled vehicle in the embodiment, it can be applied to all vehicles and can be used for purposes other than vehicles.

  The purification device manufacturing method of the present invention is suitable for manufacturing a four-wheel vehicle purification device.

10, 10A ... Catalyst device (exhaust gas purification device)
11 ... Catalyst carrier (purification member)
11a: end of catalyst carrier (end of purification member)
DESCRIPTION OF SYMBOLS 12 ... Mat 20, 20A ... Case 21 ... General part 21a ... End part (general part) 22 ... Vertical wall 22a ... End part (on the axial side of a vertical wall) 23, 23A ... Reduced diameter part L1 ... Tip of vertical wall A line extending parallel to the axis from the portion L2 ... tangent L2A ... extension line CL ... axis

Claims (3)

In an exhaust gas purification apparatus comprising a purification member, a mat wound around the purification member, and a cylindrical case that houses the purification member and the mat,
The case includes a general part wound around the outer periphery of the mat, a vertical wall bent substantially perpendicularly toward an axis of the case from an end of the general part, and the axial side of the vertical wall. A reduced diameter portion that is reduced in diameter from the end portion,
The vertical wall is formed apart from the purification member,
A line extending in parallel to the axis from the tip of the vertical wall contacts the purification member,
The reduced diameter portion has a shape in which the radius of curvature continuously changes,
An exhaust gas purification apparatus, wherein a tangent at an end of the reduced diameter portion on the vertical wall side is in contact with the purification member. In an exhaust gas purification apparatus comprising a purification member, a mat wound around the purification member, and a cylindrical case that houses the purification member and the mat,
The case includes a general part wound around the outer periphery of the mat, a vertical wall bent substantially perpendicularly toward an axis of the case from an end of the general part, and the axial side of the vertical wall. A reduced diameter portion that is reduced in diameter from the end portion,
The vertical wall is formed apart from the purification member,
A line extending in parallel to the axis from the tip of the vertical wall contacts the purification member,
An extension line extending from an end of the reduced diameter portion on the vertical wall side is in contact with the purification member.   The exhaust gas purification device according to claim 1 or 2, wherein the reduced diameter portion has an uneven portion formed in an uneven shape.

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