US-20260125998-A1 - EXHAUST TREATMENT DEVICE

Abstract

An exhaust treatment device includes an injection unit that injects urea water into the exhaust pipe, a first plate that is provided upstream of the injection unit in the exhaust pipe, an arc-shaped second plate that is provided along the axial direction in the exhaust pipe and faces the injection unit, and a third plate that is provided downstream of the second plate in the exhaust pipe, wherein the first plate includes a first inflow hole formed at a position away from a central portion thereof, and a guide portion configured to direct the exhaust gas introduced from the first inflow hole toward the injection portion, and the third plate includes an outflow hole formed in a central portion thereof.

Inventors

• Shoki Ishikawa
• Junji Sakai
• Yuta KAGEYAMA
• Nobutaka Ayabe
• Tetsunori Higuchi
• Ken Miyawaki
• Kazuki Kusunoki
• Dai Ishikuro

Assignees

• ISUZU MOTORS LIMITED

Dates

Publication Date

20260507

Application Date

20251010

Priority Date

20241101

Claims (20)

1. 1 . An exhaust treatment device comprising: an exhaust pipe through which exhaust gas flows; an injection unit that injects urea water into the exhaust pipe; a first plate that is provided upstream of the injection unit in the exhaust pipe in a manner to be orthogonal to an axial direction of the exhaust pipe; an arc-shaped second plate that is provided along the axial direction in the exhaust pipe and faces the injection unit; and a third plate that is provided downstream of the second plate in the exhaust pipe in a manner to be orthogonal to the axial direction, wherein the first plate includes a first inflow hole formed at a position away from a central portion thereof, and a guide portion configured to direct the exhaust gas introduced from the first inflow hole toward the injection portion, and the third plate includes an outflow hole formed in a central portion thereof.
2. 2 . The exhaust treatment device according to claim 1 , wherein the first plate is a disk, and when the first plate and the second plate are viewed from the third plate, the first inflow hole is located at a position different from that of the second plate in the circumferential direction of the first plate.
3. 3 . The exhaust treatment device according to claim 1 , wherein the injection unit is located at an upper end portion of the exhaust pipe in a vertical direction, and the first inflow hole is located at the same position as the outflow hole in the vertical direction.
4. 4 . The exhaust treatment device according to claim 3 , wherein the first inflow hole is a rectangular hole, and the guide portion is provided obliquely upward in the vertical direction from a lower edge of the first inflow hole.
5. 5 . The exhaust treatment device according to claim 3 , wherein the first plate is a disk, and a center of the first inflow hole is located farther from a center of the first plate than the outflow hole in a radial direction of the first plate.
6. 6 . The exhaust treatment device according to claim 1 , wherein the first plate is a disk having a first radius, the second plate has a semicylindrical shape having a second radius smaller than the first radius, and one end portion of the second plate in an axial direction is in contact with the first plate.
7. 7 . The exhaust treatment device according to claim 6 , wherein the first plate includes a plurality of second inflow holes provided at predetermined intervals along the second plate closer to the center of the first plate with respect to the second plate.
8. 8 . The exhaust treatment device according to claim 7 , wherein the second inflow hole is located at a position different from that of the first inflow hole in the circumferential direction of the first plate.
9. 9 . The exhaust treatment device according to claim 6 , wherein the first plate includes a third inflow hole provided along the second plate, at a position closer to an edge of the first plate than the second plate.
10. 10 . The exhaust treatment device according to claim 1 , wherein the first plate includes a second inflow hole formed at a position adjacent to an inner circumferential surface of the second plate and spaced apart from the first inflow hole by a predetermined angle in a circumferential direction.
11. 11 . The exhaust treatment device according to claim 10 , wherein the first plate further includes a guide portion configured to direct the exhaust gas introduced from the second inflow hole toward the inner circumferential surface of the second plate.
12. 12 . The exhaust treatment device according to claim 11 , wherein the second inflow hole is a rectangular hole, and the guide portion is provided obliquely downward in the vertical direction from an upper edge of the second inflow hole.
13. 13 . The exhaust treatment device according to claim 1 , wherein the first plate includes a fourth inflow hole that is formed at a position where the second plate is not provided in the circumferential direction and into which the exhaust gas flows, and the fourth inflow hole is formed at a position adjacent to the injection unit in the circumferential direction.
14. 14 . The exhaust treatment device according to claim 13 , wherein the second plate includes a bent portion that is formed at an end portion in the circumferential direction and is connected to the exhaust pipe, and the fourth inflow hole is located between the injection unit and the bent portion in the circumferential direction.
15. 15 . The exhaust treatment device according to claim 1 , wherein one end portion of the second plate in the axial direction is in contact with the first plate, and the other end portion of the second plate in the axial direction is in contact with the third plate.
16. 16 . An exhaust treatment device comprising: an exhaust pipe through which exhaust gas flows; an injection unit that injects urea water into the exhaust pipe; a first plate that is provided upstream of the injection unit in the exhaust pipe in a manner to be orthogonal to an axial direction of the exhaust pipe; an arc-shaped second plate that is provided along the axial direction in the exhaust pipe and faces the injection unit; and a third plate that is provided downstream of the second plate in the exhaust pipe in a manner to be orthogonal to the axial direction, wherein the first plate includes an inflow hole into which the exhaust gas flows, and the third plate includes i) a protruding portion protruding toward the first plate and ii) an outflow hole formed at a distal end of the protruding portion.
17. 17 . The exhaust treatment device according to claim 16 , wherein the third plate further includes a flat plate portion in a manner to be orthogonal to the axial direction, and an outer diameter of the protruding portion increases from the tip of the protruding portion toward a connection point with the flat plate portion.
18. 18 . The exhaust treatment device according to claim 17 , wherein an outer peripheral surface of the protruding portion is curved from the tip of the protruding portion toward the connection point.
19. 19 . The exhaust treatment device according to claim 16 , wherein the protruding portion is cylindrical in shape.
20. 20 . The exhaust treatment device according to claim 16 , wherein the third plate is a circular flat plate, and the protruding portion protrudes from a central portion of the third plate toward the first plate.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority to Japanese Patent Applications number 2024-193155, filed on Nov. 1, 2024, Japanese Patent Applications number 2025-57842, filed on Mar. 31, 2025, and Japanese Patent Applications number 2025-57843, filed on Mar. 31, 2025, contents of which are incorporated herein by reference in their entirety. BACKGROUND OF THE INVENTION The present disclosure relates to an exhaust treatment device that purifies exhaust gas. Japanese Unexamined Patent Application Publication No. 2018-123788 discloses a technique in which urea water is injected from an injector toward an impactor provided in an exhaust passage through which exhaust gas flows, and the urea water adhering to the impactor is evaporated by the exhaust gas to generate ammonia gas. However, in the above-described technique, since the urea water injected by the injector tends to adhere only to a partial region of the impactor, it is difficult to efficiently evaporate the urea water. BRIEF SUMMARY OF THE INVENTION The present disclosure focuses on this point, and an object thereof is to efficiently evaporate injected urea water. A first aspect of the present disclosure provides an exhaust treatment device including an exhaust pipe through which exhaust gas flows, an injection unit that injects urea water into the exhaust pipe, a first plate that is provided upstream of the injection unit in the exhaust pipe in a manner to be orthogonal to an axial direction of the exhaust pipe, an arc-shaped second plate that is provided along the axial direction in the exhaust pipe and faces the injection unit, and a third plate that is provided downstream of the second plate in the exhaust pipe in a manner to be orthogonal to the axial direction, wherein the first plate includes a first inflow hole formed at a position away from a central portion thereof, and a guide portion configured to direct the exhaust gas introduced from the first inflow hole toward the injection portion, and the third plate includes an outflow hole formed in a central portion thereof. A second aspect of the present disclosure provides an exhaust treatment device including an exhaust pipe through which exhaust gas flows, an injection unit that injects urea water into the exhaust pipe, a first plate that is provided upstream of the injection unit in the exhaust pipe in a manner to be orthogonal to an axial direction of the exhaust pipe, an arc-shaped second plate that is provided along the axial direction in the exhaust pipe and faces the injection unit, and a third plate that is provided downstream of the second plate in the exhaust pipe in a manner to be orthogonal to the axial direction, wherein the first plate includes an inflow hole into which the exhaust gas flows, and the third plate includes i) a protruding portion protruding toward the first plate and ii) an outflow hole formed at a distal end of the protruding portion. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically shows a configuration of an exhaust treatment device 1 according to an embodiment. FIG. 2 schematically shows a peripheral configuration of an injection unit 16 in an exhaust passage 12. FIG. 3 schematically shows an internal configuration of FIG. 2. FIG. 4 schematically shows a configuration of an exhaust pipe 13 of FIG. 2 viewed from the rear. FIG. 5 schematically shows the configuration of the exhaust pipe 13 of FIG. 2 as viewed from the front. FIG. 6 is a schematic view for explaining a flow of exhaust gas in an injection space. FIG. 7 schematically shows the peripheral configuration of the injection unit 16 of an exhaust pipe 13 according to a second embodiment. FIG. 8 schematically shows an internal configuration of FIG. 7. FIG. 9 schematically shows a configuration of the exhaust pipe 13 of FIG. 7 as viewed from the front. FIG. 10 schematically shows the configuration of the exhaust pipe 13 of FIG. 7 as viewed from the rear. FIG. 11 is a schematic view for explaining flows of exhaust gas and urea water in an injection period. DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the present disclosure will be described through exemplary embodiments of the present disclosure, but the following exemplary embodiments do not limit the disclosure according to the claims, and not all of the combinations of features described in the exemplary embodiments are necessarily essential to the solution means of the disclosure. First Embodiment Configuration of Exhaust Treatment Device FIG. 1 schematically shows a configuration of an exhaust treatment device 1 according to an embodiment. As shown in FIG. 1, the exhaust treatment device 1 includes an engine 10, an exhaust passage 12, a Diesel Particulate Filter (DPF) 14, an injection unit 16, and a Selective Catalytic Reduction (SCR) device 18. As an example, the exhaust treatment device 1 is mounted on a vehicle such as a truck, and purifies exhaust gas from the engine 10. The engine 10 is an internal combustio