JPS6311294Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an exhaust particulate trap installed in an exhaust system as a device for collecting and regenerating particulates discharged from an internal combustion engine, particularly a compression ignition engine (diesel engine). In particular, it relates to a trap equipped with an electric heater as an auxiliary means for regeneration.

Part of the mainly carbon-based particulates collected in the trapping material is ignited by an electric heater, and then the trapping material is regenerated by self-combustion of the particulates. The electric heater is supported in close contact with the upstream end of the trap material in order to reliably ignite the particulate.
It takes a considerable amount of power to ignite the particulate to the extent that it completely self-combusts. The reason for this is that the element portion of the electric heater is cooled by the flow of exhaust gas, and that the amount of particulate deposited near the heater element necessary for ignition is small.

The purpose of this invention is to solve these problems, and in particular, to develop an exhaust part filter that minimizes the cooling of the electric heater element due to the flow of exhaust gas and reliably ignites the particulate with low power consumption. The goal is to provide a curate trap.

In order to achieve this purpose, the present invention uses a linear or plate-shaped electric heater element disposed on the upstream end face of the trap material, and a short distance from the electric heater element immediately upstream of the electric heater element. A protective wall is provided that extends along the heater element and separates the heater element.

With such a protective wall, a stagnation area is formed on the back side of the wall, that is, near the heater element, where exhaust gas does not directly flow, reducing cooling loss due to the flow of exhaust gas from the heater element, and preventing exhaust soot (flammable particulates) from flowing into the stagnation area. It is now possible to attach more. As a result, it has become possible to improve the ignitability of the deposited particulate using the electric heater.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view of an exhaust particulate trap according to the present invention. A cylinder trap container 1 is provided in an exhaust pipe line downstream of an exhaust manifold (not shown) of a diesel engine, and a trap material 2 is disposed inside the cylinder trap container 1. As the trap material 2, a known foamed ceramic or a similar material can be used. That is, the trap material has a three-dimensional mesh structure, and when exhaust gas is discharged in the direction of arrow P in FIG. It is now possible to collect them in between. An electric heater 3 is disposed in close contact with the upstream end surface of the trap material 2.
A protective wall 10 is provided immediately upstream of the tank, as will be described later. In addition, in FIG. 1, 4 is the anode side of the electric heater 3, that is, a terminal for power supply.

FIG. 2 is a view of the front of the trap taken along the line - in FIG. Further, FIG. 3 is an enlarged sectional view of the portion indicated by the dotted line in FIG. 1. The electric heater 3 consists of a plurality of heater elements 3a, 3b, . . . . Although FIG. 2 only shows two semicircular heater elements 3a and 3b, a plurality of smaller semicircular heater elements can be arranged inside the heater elements 3a and 3b. These heater elements are made of, for example, Fe-Cr-A and have a plate-like or linear shape, and are closely attached to the upstream end surface of the trap material 2 by some means, such as adhesive.

Immediately upstream of each electric heater element 3a, 3b... is a protective wall 1 extending along the heater element at a short distance from the heater element.
0a, 10b... are provided. Although FIG. 2 only shows two semicircular protective walls 10a and 10b corresponding to the two heater elements 3a and 3b, protective walls are provided corresponding to all the heater elements. As shown in FIG. 4, the protective wall 10 preferably has a bowl-shaped cross-section so as to cover the heater element 3, with the concave surface of the bowl-shaped face facing the electric heater element 3 side. In addition, the heater element 3 and the protective wall 10
It is desirable that the distance between the two is within 5 mm.

According to the present invention, in FIGS. 1 and 4,
Even if the exhaust gas flows in the direction of arrow P, a stagnation region is formed in the vicinity of the electric heater element 3 by the protective wall 10, so that the heater element 3 is not cooled by the exhaust gas. Furthermore, particulates in the exhaust gas tend to adhere to such stagnation areas, and when the trap material 2 is regenerated (regeneration of the trap material 2 is performed regularly or periodically), the heater element 3 When the heater element is energized and generates heat, the particulate attached near the heater element can be reliably ignited with low power consumption. As a result, the particulates adhering to the entire area of the trap material 2 are also completely combusted, and the regeneration efficiency of the trap material 2 is improved.

In addition, in FIG. 3, 1a is the trap container 1.
1b is a slit portion, 5 is a ring member for fixing the trap material 2, 6 is a wire net, 7 is an insulator, 13 is a terminal bolt, 15 is an electric heater 3
This is the lead wire.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the exhaust particulate trap of the present invention, Fig. 2 is a view of the front of the trap as seen from the line - in Fig. 1, and Fig. 3 is an enlarged sectional view of the part indicated by . , FIG. 4 is a perspective view showing the electric heater element and the protective wall. 1... Trap container, 2... Trap material, 3...
...Electric heater, 10...protective wall.

Claims (1)

[Scope of utility model registration request] In an exhaust particulate trap in which a trap material capable of collecting engine exhaust particulates is provided inside a trap container in an exhaust passage, a linear or A plate-shaped electric heater and a plate extending along the electric heater provided immediately upstream of the electric heater at a short distance from the electric heater to prevent the electric heater from being cooled by the flow of exhaust gas. Exhaust particulate trap including protective wall.