JPS6139058Y2 - - Google Patents

Description

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

The electric heater must be closely supported on the upstream end surface of the trap material in order to ignite the mainly carbon-based particulates collected in the trap. As such a close support method,
The following methods have been proposed.

Attach an electric heater to the honeycomb filter and press it together with the honeycomb filter onto the surface of the trap material.

An electric heater is embedded in a depression in the surface of the trap material.

Simply attach the electric heater to the surface of the trap material using adhesive or the like.

In the case of: In order to attach the heater to the honeycomb filter, the honeycomb filter must be specially processed to fit into the trap, which increases the price and also poses problems in assembly.

In the case of: It is difficult to create depressions on the surface of the trap material, and there are also problems with the method of attaching the heater to the depressions. Sometimes the heater and trap material do not come into close contact.

In the case of: The heater comes off easily or there is a problem with the adhesion.

Therefore, the purpose of the present invention is to achieve the following items with a simple structure.

(1) By making it easier to assemble the heaters into the trap, it prevents shots etc. due to contact between the heaters and increases the lifespan of the heaters.

(2) By ensuring the contact between the heater and the filter, the efficiency of the heater as a regeneration means is improved.

In order to achieve such an object, the present invention provides an exhaust particulate trap in which a trap material capable of collecting exhaust particulates of a diesel engine is provided inside a cylindrical trap container. a frame portion adjacent to the inner circumferential wall of the container at the upstream end face of the trap material and for fixing the trap material to the container; and an electric heater element located inside the frame portion and attached to the trap material. An exhaust particulate trap is proposed, characterized in that it includes a metal support member integrally formed with a presser portion for pressing the electric heater element, and the electric heater element is grounded to the support member.

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 cylindrical 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 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 arranged on the upstream end surface of the trap material 2, and this electric heater 3 is supported by a support member 10 as described later.
In FIG. 1, 4 is the anode side of the electric heater 3, that is, a terminal for power supply.

FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG. 3 is an enlarged sectional view of the portion indicated by . The electric heater 3 includes a plurality of electric heater elements 3a,
3b, 3c..., these are made of Fe-Cr-Al and have a rectangular or zigzag shape to increase the contact area with the trap material 2. The support member 10 includes a frame portion 11 adjacent to the inner peripheral wall of the trap container 1 at the upstream end surface of the trap material 2, and a plurality of linear portions (heater pressing portions) that press the electric heater 3 against the end surface of the trap material 2. )12. As shown in FIGS. 4 and 5, the support member 1
The frame portion 11 of the trap container 1 has a radial flange portion 11a in contact with the inner circumferential wall of the trap container 1, and a trap member 2 slightly inside from the outermost flange portion 11a.
It has another part 11b bent in the axial direction on the side thereof. The linear portion or heater holding portion 12 of the support member 10 has a radial portion that is on the same plane as the flange portion 11a, is connected to the flange portion 11a, extends radially inward, and passes through the center, and a radial portion that extends radially inwardly and passes through the center. It consists of a plurality of circular or elliptical parts 12a, 12b, and 12c that connect the parts (Fig. 2). The support member 10 having the frame portion 11 and the linear presser portion 12 is integrally formed by press-molding a heat-resistant metal such as SUS material.

Zigzag-shaped electric heater elements 3a, 3b, 3c
... are arranged along the linear presser portion 12. In particular, the electric heater elements 3a are arranged in a zigzag shape alternately outward and inward along the large circular portion 12a, and the electric heater elements 3b, 3c are similarly arranged along the medium and small circular portions 12b, 12c, respectively. They are arranged alternately outward and inward in a zigzag shape. Due to this arrangement, the central portion of the electric heater element is pressed from directly above. The contact area of the linear presser portion 12 with the electric heater element is coated with ceramic or oxide film 12' to improve insulation. (See Figure 6) Each electric heater element 3a, 3
One end of b, 3c is connected to each lead wire 15 (FIG. 3), and each lead wire is connected to the support member 1 through an insulator 16 fixed to the collar portion 11b of the support member 10.
Extracted from 0. The other end of each electric heater element is fixed to the holding part 12 of the support member 10 and is grounded. These grounding parts are indicated by E in Figure 2.

The assembly order of the particulate trap according to the embodiment of the present invention is as follows. First, the support member 10 (heater assembly) with the electric heater 3 and the lead wire 15 is inserted into the trapper container 1 . The support member 10 is held on the front wall step 1a (FIG. 3) of the trap vessel 1. At the same time, the lead wire 15 is passed through the slit portion 1b (FIG. 3) of the container 1. Subsequently, the annular cushion member 5 is placed over the space defined by the flange portion 11a of the support member 10, the collar portion 11b, and the inner circumference of the container 1. Next, the wire net 6 is wrapped around the entire outer circumference of the trap material 2 and press-fitted into the container 1, and a cushion member (not shown) is attached to the opposite side to fix the trap material 2 to the trap container 1. do. When the trap material 2 is fixed, the collar portion 11b of the support member 10 is slightly (1 mm) attached to the end surface of the trap material 2.
degree) and firmly supports the trap material 2. Finally, connect the lead wire 15 of the electric heater to the insulator 7.
(Fig. 3), then insulator 7 and bolt 13
to the outside of the container 1. The lead wire 15 taken out from the insulator 7 to the outside is connected to a power source such as a battery.

According to the present invention, it is possible to support the trap material 2 and the electric heater 3 using the integrally molded support member 10 with a simple structure, and it is easy to assemble, and the electric heater is provided with a special ground. There is no need to provide one, and costs can be reduced. In particular, in the present invention, the electric heater 3 has good adhesion to the trap material 2, and movement of the electric heater due to vibrations or the like is suppressed.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the exhaust particulate trap of the present invention, Fig. 2 is a sectional view taken along the line - in Fig. 1, Fig. 3 is an enlarged sectional view of the part indicated by the symbol in Fig. 1, and Fig. 4. and FIG. 5 are enlarged sectional views of the support member taken along lines - and 2 of FIG. 2, respectively;
FIG. 6 is a perspective view showing a joined state of the electric heater and the heater holder. 1... Trap container, 2... Trap material, 3...
...Electric heater, 10... Support member, 11... Frame portion, 12... Linear presser portion.

Claims (1)

[Scope of utility model registration request] In an exhaust particulate trap, in which a trap material 2 capable of collecting exhaust particulates of a diesel engine is provided inside a cylindrical trap container 1, an upstream end surface of the trap material 2 is placed inside the container. a frame 11 adjacent to the peripheral wall and for fixing the trapping material to the container;
It includes a metal support member 10 which is located inside the frame and is integrated with a presser part 12 for pressing the electric heater element 3 against the trap material,
An exhaust particulate trap characterized in that said electric heater element is grounded to said support member.