ELECTRICALLY HEATED CATALYTIC DEVICE AND VEHICLE EQUIPPED WITH ELECTRICALLY HEATED CATALYTIC DEVICE

• US 20120011834A1
• Filed: 07/13/2011
• Published: 01/19/2012
• Est. Priority Date: 07/15/2010
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: SOBUE, Kazuaki
• Granted Patent: US 8,701,394 B2
• Time in Patent Office: Days
• US Class Current: 60/300
• CPC Class Codes: F01N 3/2013 using electric or magnetic heating means
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An electrically heated catalytic device includes an electrically heated catalyst accommodated in an outer casing provided on an exhaust pipe. A heater ring made of an insulating material is provided adjacent to an outer peripheral edge portion of an upstream end face of the electrically heated catalyst. The heat of the electrically heated catalyst is transferred to the heater ring by generating resistive heat in the electrically heated catalyst. When the soot in exhaust gas accumulates on the surface of the heater ring, the deposits of soot is removed through combustion by the heat from the surface of the heater ring.

Claims

1. An electrically heated catalytic device provided in an exhaust pipe, comprising:

an outer casing;

an electrically heated catalyst that includes;

an energization-exothermic substrate that is formed of a resistive heating material, allows exhaust gas to flow therethrough, and is so retained in the outer casing as to allow energization from an outside in a state of being insulated from an inner wall of the outer casing; and

a metal catalyst carried on the energization-exothermic substrate;

a heater ring that is disposed on an upstream side of the electrically heated catalyst with respect to the exhaust pipe in a state of being in contact with an outer peripheral edge portion of an upstream end face of the electrically heated catalyst, and is made of an insulating material; and

a soot combustion mechanism that eliminates soot, which is carried in exhaust gas, deposited on the heater ring by heating the heater ring using heat generated through resistive heating of the energization-exothermic substrate to combust the soot.

2. The electrically heated catalytic device according to claim 1, further comprising:

an insulating mat that is arranged between an inner wall of the outer casing and the electrically heated catalyst to insulate the electrically heated catalyst from the inner wall of the outer casing.

3. The electrically heated catalytic device according to claim 2, wherein the insulating mat is formed of a ceramic material.

4. The electrically heated catalytic device according to claim 1, wherein the soot combustion mechanism includes a dense portion that is formed at regions of the electrically heated catalyst that overlap with the heater ring, and that is formed of a material that generates resistive heat.

5. The electrically heated catalytic device according to claim 4, wherein the dense portion is formed on the upstream end of the electrically heated catalyst over an area that is adjacent to the heater ring.

6. The electrically heated catalytic device according to claim 1, further comprising

an upstream catalyst that is arranged in the outer casing upstream of the electrically heated catalyst, and separated from the electrically heated catalyst by a gap, wherein

the heater ring is positioned in the gap between the electrically heated catalyst and the upstream catalyst.

7. The electrically heated catalytic device according to claim 1, further comprising

a downstream catalyst that is arranged downstream of the electrically heated catalyst, and separated from the electrically heated catalyst by a gap.

8. A vehicle comprising:

an engine; and

the electrically heated catalytic device according to claim 1.