DE-102025128392-A1 - EXHAUST ENGINE

Abstract

An exhaust gas control device comprises projections and recesses. A region defined by cut sections is a through-hole. The projections and recesses are arranged alternately in at least one longitudinal direction and in one lateral direction via predetermined flat connecting sections. A plurality of metal sheets with catalysts, attached on a front surface with the projections and on a rear surface with the recesses, are stacked such that the projections and the recesses are offset from each other in the lateral direction. The metal sheets adjacent in a stacking direction are joined and connected at least by the connecting sections.

Inventors

• Hiroyoshi UEDA
• Hiromu Ono Sasaki

Assignees

• TOYOTA JIDOSHA KABUSHIKI KAISHA

Dates

Publication Date

20260513

Application Date

20250718

Priority Date

20241112

Claims (5)

1. An exhaust gas control device designed to control exhaust gas produced by combustion by causing the exhaust gas to flow along a metal sheet that is a catalyst-supporting substrate, the exhaust gas control device comprising: projections, each serving as a gas channel, projecting such that a strip defined by two cut sections located at the front and rear in a longitudinal direction of the metal sheet in which the exhaust gas flows is bent or curved towards a front surface side that is a surface side of the metal sheet; and recesses, each serving as a gas channel, are set back such that another strip, defined by two other cut sections located at the front and rear, in the longitudinal direction of the metal sheet in which the exhaust gas flows, is bent or curved to a rear surface side, which is the other surface side of the metal sheet, wherein a section defined by the cut sections is a through-hole, the projections and the recesses are arranged in at least either the longitudinal direction and/or a lateral direction perpendicular to the longitudinal direction via predetermined flat connecting sections, a plurality of the metal sheets with the catalysts attached to the front surface side comprising the projections and the rear surface side comprising the recesses are stacked such that the projections are offset from one another in the lateral direction and the recesses are offset from one another in the lateral direction, and the metal sheets adjacent to one another in a stacking direction are joined and connected at least by the flat connecting sections.
2. Exhaust control device according to Claim 1 , wherein: an upper surface of each of the projections is connected to the flat connecting section of another of the metal sheets, which is arranged upwards in the stacking direction; and a bottom surface of each of the depressions is connected to the flat connecting section of yet another of the metal sheets, which is arranged downwards in the stacking direction.
3. Exhaust control device according to Claim 1 or 2 , wherein: the projections and the depressions of the metal sheet are arranged alternately in the lateral direction; and the projections and the depressions are arranged alternately in the longitudinal direction and are offset from each other in the lateral direction.
4. Exhaust control device according to Claim 1 or 2 , wherein: the projections of the metal sheet are arranged in a plurality of rows in the lateral direction; and the recesses are arranged in the lateral direction between the rows of projections.
5. Exhaust control device according to Claim 1 or 2 , where: a length of the flat connecting section in the longitudinal direction is a predetermined length with an upper limit that is a length Le determined by the following expression; and a length of each of the projections and recesses in the longitudinal direction is a predetermined length with an upper limit that is half the length Le determined by the following expression: Le = { dH / 9.28 × √ ( ρ − u / μ ) } 2 where dH is a hydraulic diameter expressed in the unit meter, ρ is a gas density expressed in the unit kg/m 3 , u is a gas flow rate expressed in a unit m/s, and µ is a gas viscosity expressed in a unit pas.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention The present invention relates to a device that controls exhaust gas by supporting a catalyst on a substrate and causing the exhaust gas to flow along the substrate, and in particular to a structure of a substrate that carries a catalyst. 2. Description of the related prior art Exhaust gases produced by vehicle combustion engines contain pollutants such as carbon monoxide (CO) and hydrocarbons (HC). Catalytic converters are installed in the exhaust systems of combustion engines to oxidize or reduce these pollutants, thereby rendering them harmless. To control the exhaust gas using a catalytic converter, it is necessary to actively bring the exhaust gas into contact with the catalyst. Various structures have been proposed for this purpose. The unexamined Japanese patent application disclosure no. 11-290699 ( JP 11-290699 A ) discloses a honeycomb catalyst for flue gas denitrification. The honeycomb catalyst consists mainly of a honeycomb structure that supports a catalyst, and a large number of holes formed inside the honeycomb structure serve as gas channels. If the gas channel is long, a boundary film grows along the inner surface of the hole to increase the diffusion resistance of the exhaust gas across the catalyst. In the in JP 11-290699 A The described honeycomb catalyst has a large number of recesses in the gas channel with distances between them of 300 mm or less. The unexamined Japanese patent application disclosure document (translation of the PCT application) No. 2007-511699 ( JP 2007-511699 A ) discloses an exhaust gas control converter for an internal combustion engine that uses a metal fiber plate to support a catalyst. In the case of the JP 2007-511699 A The exhaust gas control converter shown has a metal sheet sandwiched between plates to form a single stack, and multiple stacks of these stacks are layered and housed within a casing. In each stack, the exhaust gas flows between and through the plates to come into contact with the catalyst. This is how the exhaust gas is controlled. To create a channel for this exhaust gas flow, the metal sheet is equipped with fins that protrude from one of its surfaces. The fin is a curved piece formed by cutting a portion of the metal sheet, for example, along three sides of a rectangle. The fin is bent along the remaining four sides of the rectangle so that it protrudes from one surface of the metal sheet. The rectangular portion has a hole through it. BRIEF SUMMARY OF THE INVENTION In an exhaust gas control device, the temperature of the exhaust gas being treated is high. Furthermore, oxidation and reduction reactions of pollutants occur in the exhaust gas. Therefore, the heat generated by these reactions can lead to a temperature increase. When the device is mounted on a vehicle, it can vibrate considerably while driving. The exhaust gas control device is inevitably subjected to such thermal stress and external forces. During the JP 11-290699 A In the revealed configuration, the honeycomb structure is interrupted, for example, at the slots, and the strength of these parts is low. As a result, the honeycomb structure deforms or shifts due to thermal stress or vibration, leading to frictional contact or collisions between the honeycomb structures. Furthermore, the honeycomb structures can be damaged. At the in JP 2007-511699 A In the exhaust gas control converter described, the exhaust gas flows over the plates, each made of metal fibers, which support the catalyst, and the exhaust gas comes into contact with the catalyst. In this way, the exhaust gas is controlled. Since the plates are arranged parallel to the direction of exhaust gas flow, it is desirable for the exhaust gas to be distributed over the entire surface of the plates. For this purpose, the metal sheet is positioned between the plates, and the vanes serve as spacers. That is, the metal sheet in the JP 2007-511699 A The exhaust gas control converter described is a component for maintaining the distance between the plates and has no specific function for controlling the exhaust gas. Therefore, the one described in JP 2007-511699 A The exhaust gas control converter described here has a large number of components. This can lead to an increase in the overall configuration of the device. In particular, the number of metal sheets and stacks increases, resulting in an increase in weight and, furthermore, an increase in cost. The present invention is based on the objective of providing an exhaust gas control device in which the number of required components can be reduced, while the strength is significantly improved. gend is and the efficiency of the exhaust gas control can be improved by adequately securing an exhaust gas channel. To achieve the aforementioned objective, the present invention provides an exhaust gas control device configured to control the exhaust gas produced by combustion by directing the exhaust gas flow along a metal sheet tha