US-12618352-B2 - Exhaust purification apparatus

US12618352B2US 12618352 B2US12618352 B2US 12618352B2US-12618352-B2

Abstract

An exhaust purification apparatus includes a connection portion that connects an exhaust manifold to a catalytic converter. The connection portion includes a diffusion portion and a coupling portion. The coupling portion is configured such that a cross-sectional area of a passage of the coupling portion increases from a connection point with the diffusion portion toward a connection point with the catalytic converter. The side surface of the diffusion portion includes a connection surface to which the exhaust manifold is connected, a collision surface with which the exhaust gas that has flowed into the diffusion portion from the exhaust manifold strikes, a first coupling surface, and a second coupling surface. Cross-sectional shapes of the first coupling surface, the second coupling surface, and the collision surface are arcuate. The cross-sectional shape of the collision surface has a smaller curvature than the cross-sectional shapes of the first and second coupling surfaces.

Inventors

Hiroshi Oyagi
Hirokazu Ito
Kazuhiko Seguchi

Assignees

TOYOTA JIDOSHA KABUSHIKI KAISHA

Dates

Publication Date: 20260505
Application Date: 20250324
Priority Date: 20240507

Claims (3)

1 . An exhaust purification apparatus, comprising: an exhaust manifold; a cylindrical catalytic converter; and a connection portion that connects the exhaust manifold to the catalytic converter, wherein the exhaust purification apparatus is configured such that exhaust gas that has flowed from the exhaust manifold into the connection portion is directed to the catalytic converter, the connection portion includes: a tubular diffusion portion to which the exhaust manifold is connected; and a coupling portion that couples the diffusion portion to the catalytic converter, the diffusion portion is arranged such that a central axis of the diffusion portion aligns with a central axis of the catalytic converter, the coupling portion is configured such that a cross-sectional area of a passage of the coupling portion increases from a connection point with the diffusion portion toward a connection point with the catalytic converter, a side surface of the diffusion portion includes: a connection surface to which the exhaust manifold is connected; a collision surface arranged such that a central axis of the diffusion portion is positioned between the collision surface and the connection surface, wherein exhaust gas that has flowed from the exhaust manifold into the diffusion portion collides with the collision surface; a first coupling surface that couples an upper end of the connection surface to an upper end of the collision surface; and a second coupling surface that couples a lower end of the connection surface to a lower end of the collision surface, and cross-sectional shapes of the first coupling surface, the second coupling surface, and the collision surface along a plane orthogonal to the central axis of the diffusion portion are arcuate, wherein a curvature of the cross-sectional shape of the collision surface is smaller than curvatures of the cross-sectional shapes of the first coupling surface and the second coupling surface.
2 . An exhaust purification apparatus, comprising: an exhaust manifold; a cylindrical catalytic converter; and a connection portion that connects the exhaust manifold to the catalytic converter, wherein the exhaust purification apparatus is configured such that exhaust gas that has flowed from the exhaust manifold into the connection portion is directed to the catalytic converter, the connection portion includes: a tubular diffusion portion to which the exhaust manifold is connected; and a coupling portion that couples the diffusion portion to the catalytic converter, the diffusion portion is arranged such that a central axis of the diffusion portion aligns with a central axis of the catalytic converter, the coupling portion is configured such that a cross-sectional area of a passage of the coupling portion increases from a connection point with the diffusion portion toward a connection point with the catalytic converter, a side surface of the diffusion portion includes: a connection surface to which the exhaust manifold is connected; a collision surface arranged such that a central axis of the diffusion portion is positioned between the collision surface and the connection surface, wherein exhaust gas that has flowed from the exhaust manifold into the diffusion portion collides with the collision surface; a first coupling surface that couples an upper end of the connection surface to an upper end of the collision surface; and a second coupling surface that couples a lower end of the connection surface to a lower end of the collision surface, and the collision surface is flat.
3 . The exhaust purification apparatus according to claim 2 , wherein cross-sectional shapes of the first coupling surface and the second coupling surface along a plane orthogonal to the central axis of the diffusion portion are arcuate.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2024-075270, filed on May 7, 2024, the entire contents of which are incorporated herein by reference. BACKGROUND 1. Field The present disclosure relates to an exhaust purification apparatus installed in an internal combustion engine. 2. Description of Related Art Japanese Laid-Open Patent Publication No. 2006-9793 discloses an example of an exhaust purification apparatus. This apparatus includes an exhaust manifold, a catalytic converter, and a swirling flow generator positioned between the exhaust manifold and the catalytic converter. In the exhaust purification apparatus, when exhaust gas flow from the exhaust manifold into the swirling flow generator, a swirl flow of the exhaust gas is generated in the swirling flow generator. This results in the diffusion of the exhaust gas flow that enters the catalytic converter. In the exhaust purification apparatus, the condensed water generated in the exhaust manifold flows into the swirling flow generator, which is located below the exhaust manifold. The outflow portion for guiding exhaust gas to the catalytic converter is connected to a part above the lowermost portion of the swirling flow generator. Therefore, there is a risk that condensed water may accumulate in the swirling flow generator. SUMMARY This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. A first aspect of the present disclosure provides an exhaust purification apparatus. The exhaust purification apparatus includes an exhaust manifold, a cylindrical catalytic converter, and a connection portion that connects the exhaust manifold to the catalytic converter. The exhaust purification apparatus is configured such that exhaust gas that has flowed from the exhaust manifold into the connection portion is directed to the catalytic converter. The connection portion includes a tubular diffusion portion to which the exhaust manifold is connected, and a coupling portion that couples the diffusion portion to the catalytic converter. The diffusion portion is arranged such that a central axis of the diffusion portion aligns with a central axis of the catalytic converter. The coupling portion is configured such that a cross-sectional area of a passage of the coupling portion increases from a connection point with the diffusion portion toward a connection point with the catalytic converter. A side surface of the diffusion portion includes a connection surface to which the exhaust manifold is connected. The side surface includes a collision surface arranged such that a central axis of the diffusion portion is positioned between the collision surface and the connection surface. Exhaust gas that has flowed from the exhaust manifold into the diffusion portion collides with the collision surface. The side surface includes a first coupling surface that couples an upper end of the connection surface to an upper end of the collision surface. The side surface includes a second coupling surface that couples a lower end of the connection surface to a lower end of the collision surface. Cross-sectional shapes of the first coupling surface, the second coupling surface, and the collision surface along a plane orthogonal to the central axis of the diffusion portion is arcuate. A curvature of the cross-sectional shape of the collision surface is smaller than curvatures of the cross-sectional shapes of the first coupling surface and the second coupling surface. A second aspect of the present disclosure provides an exhaust purification apparatus. The exhaust purification apparatus includes an exhaust manifold, a cylindrical catalytic converter, and a connection portion that connects the exhaust manifold to the catalytic converter. The exhaust purification apparatus is configured such that exhaust gas that has flowed from the exhaust manifold into the connection portion is directed to the catalytic converter. The connection portion includes a tubular diffusion portion to which the exhaust manifold is connected, and a coupling portion that couples the diffusion portion to the catalytic converter. The diffusion portion is arranged such that a central axis of the diffusion portion aligns with a central axis of the catalytic converter. The coupling portion is configured such that a cross-sectional area of a passage of the coupling portion increases from a connection point with the diffusion portion toward a connection point with the catalytic converter. A side surface of the diffusion portion includes a connection surface to which the exhaust manifold is connected. The side surface includes a collision surfa