JPS6139057Y2 - - 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 surface of the trap material and fixing the trap material to the container; and an electric heater element located inside the frame portion and pressed against the trap material. The electric heater element has a zigzag shape, a strip shape, or a coil shape, and its center portion is pressed from directly above by the linear portion of the support member. An exhaust particulate trap is proposed.

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 diagram showing the state in which the electric heater 3 and the support member 10 are joined together along the line - in Fig. 1, and Fig. 3 is an enlarged cross-sectional view of the portion shown in Fig. 1. The electric heater 3 comprises a plurality of electric heater elements 3a, 3b...
These are made of Fe-Cr-Al and are in the form of a strip, a zigzag, or a coil as shown in Figs. 7 and 8 to increase the contact area with the trap material 2. The support member 10 is composed of a frame portion 11 that is adjacent to the inner peripheral wall of the trap container 1 at the upstream end face of the trap material 2, and a plurality of linear portions (heater pressing portions) 12 that press the electric heater 3 against the end face of the trap material 2. As shown in Figs. 4 and 5, the frame portion 11 of the support member 10
The flange portion 11a is in contact with the inner peripheral wall of the trap container 1, and the flange portion 11b is in contact with the inner peripheral wall of the trap container 1.
The linear portion or heater retainer portion 12 of the support member 10 is on the same plane as the flange portion 11a, and is connected to the flange portion 11a and extends radially inwardly to pass through the center of the support member 10, and has a plurality of circular portions 12a, 12b connecting the radial portions.
The support member 10 having the frame portion 11 and the linear pressing portion 12 is integrally formed by press-molding a heat-resistant metal, such as SUS material.

Zigzag-shaped, strip-shaped, or coil-shaped electric heater elements 3a, 3b, . . . are arranged along the linear holding portion 12. In particular, the outer electric heater element 3a
are arranged along the large circular portion 12a, and the inner electric heater elements 3b are arranged along the small circular portion 12b so as to alternately repeat a zigzag shape outward and inward, respectively. Due to this arrangement, the central portion of the electric heater element is pressed from directly above. Note that the contact area of the linear holding portion 12 with the electric heater element is coated with ceramic or oxide film 12' to improve insulation. (See Fig. 6) One end of each electric heater element 3a, 3b is connected to each lead wire 15 (see Fig. 3).
Each lead wire is taken out to the outside of the support member 10 via an insulator 16 fixed to the collar portion 11b of the support member 10. The other end of each electric heater element is electrically connected and fixed to a suitable location on the support member 10 to be grounded.

The assembly order of the particulate trap according to the embodiment of the present invention is as follows. First, a support member 10 (heater assembly shown in FIG. 2) having an electric heater 3 and lead wires 15 is inserted into the trap 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. Next, 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,
A cushion member (not shown) is attached to the opposite side to fix the trap material 2 to the trap container 1. With the trap material 2 fixed, support member 1
The collar portion 11b of 0 slightly (approximately 1 mm) bites into the end surface of the trap material 2 and firmly supports the trap material 2. Finally, the electric heater lead wire 1
5 is welded to an insulator 7 (FIG. 3), and then the insulator 7 is fastened to the outside of the container 1 with bolts 3. The lead wire 15 taken out from the insulator 7 is connected to an electric wire such as a battery.

FIG. 7 shows coil-shaped electric heater elements 3a', 3.
Fig. 8, which corresponds to Fig. 2 when using b',..., shows such a coiled electric heater element 3' being pressed and supported against the trap material 2 by the support member holding part 12. It is a figure showing a state. In this embodiment as well, the central portion of the coiled electric heater element 3' is pressed from directly above. The other structure is the same as that of the zigzag electric heater described above.

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 heaters 3, 3' have good adhesion to the trap material 2, and movement of the electric heaters due to vibrations, etc. is suppressed.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the exhaust particulate trap of the present invention, and FIG. 2 is a plan view of the combination of an electric heater and a support member taken along the line - in FIG. 1.
Fig. 3 is an enlarged sectional view of the part indicated by the reference numeral in Fig. 1, Figs. 4 and 5 are enlarged sectional views of the support member taken along the line - and line of Fig. 2, respectively, and Fig. 6 is an electric heater and a heater holder. FIG. 7 is a view corresponding to FIG. 2 when a coiled electric heater is used, and FIG. 8 is a partial perspective view showing the installed state of the coiled heater. 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 is connected to the inner circumferential wall of the container. a frame portion 11 adjacent to the trap material and fixing the trap material to the container; and a plurality of linear portions 12 located inside the frame portion for pressing the electric heater element 3 against the trap material. the electric heater element 3;
An exhaust particulate trap characterized in that it has a zigzag shape, a strip shape, or a coil shape, and its center portion is pressed from directly above by the linear portion 12 of the support member.