JPS6139056Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an exhaust particulate trap that collects and burns particulate matter contained in the exhaust gas of an internal combustion engine, especially a diesel engine, and particularly relates to an ignition of the collected particulate matter. This invention relates to a support structure for a heater wire serving as a heat source.

This type of exhaust particulate trap generally has a basic configuration in which a heater wire is closely attached to the front end face of a filter element for collecting particulate matter, and the heater wire is periodically energized to ignite and burn the collected particulate matter. ing. However, the lever heater wire naturally needs to be in close contact with the filter element to improve ignitability, but with conventional support structures, it is difficult to reliably hold the heater wire, which is subject to vibrations etc. in high-temperature environments, for a long period of time. As a result, it was inevitable that the heater wire would float up from the filter element, resulting in poor ignition and poor heating temperature distribution. In particular, when the heater wire is composed of a plurality of electrically insulated heater wire groups having the same resistance value, there is a problem that the individual heater wires become more easily deformed.

The purpose of this invention is to reliably prevent the heating wire from deforming or rising from the filter element with a simple structure.The invention includes a retainer that presses the heater wire from the outside against one end surface of the filter element. The retainer is fixed to a trap container, an opening is formed in the retainer to form a passage for exhaust gas, and an insulator having a support groove for the heater wire is fixed to the retainer.

The invention will now be described with reference to the illustrated embodiments. FIG. 1 shows the overall structure of this exhaust particulate trap, in which a cylindrical container 1 has a large diameter section 1a at one end and a small diameter section 1b at the other end.
A is connected to the exhaust manifold of the diesel engine, and a small diameter portion 1b is connected to the front pipe, respectively, to flow exhaust gas in the direction of the arrow. A filter element (form filter) 2 is press-fitted into the container 1 with an elastic wire net 3 wound around the entire circumference. The wire net 3 is a resilient holding member made of knitted heat-resistant fine wire and protects the filter element 2 from vibration. Further, a cushion 4 is interposed on the end surface of the filter element 2 on the side of the small diameter portion 1b, which is made by knitting thin wires and then compression molding.
This cushion 4 protects the filter element 2 from vibration, absorbs relative variations in the axial direction, and connects the heater wire 5 to the filter element 2.
It has the function of properly contacting the Further, a heat-resistant foam sealing material 6 is wrapped around the outer periphery of the end of the filter element 2 on the large diameter portion 1a side to prevent thermal deterioration of the wire net 3 and to prevent exhaust gas from passing through. The heater wire 5 consists of a plurality of electrically insulated heater wire groups as shown in FIG. 2, and each heater wire 5 is positioned on the front end surface of the filter element 2 inserted into the container 1 as described above. After that, each end thereof is welded and connected to the electrode part 7 as shown in detail in FIG. The plurality of heater wires 5 are bent in a zigzag shape with different diameters in order to increase the contact length with the filter element 2, and are made of a heat-resistant metal material, such as a Fe-Cr-Al alloy. .

However, the retainer 10 which is a feature of the present invention has the following features:
It is provided outside the heater wire 5, and its details will be explained with reference to FIG. 2 and subsequent figures.
This retainer 10 consists of an outer circumferential ring 11 and a main body 12 on the inner circumference thereof. The outer circumferential ring 11 is formed by burring a thin plate, and is provided with a rotation prevention protrusion 13 on its outer circumference.The rotation prevention protrusion 13 is inserted into the notch 8 in the end face of the container 1 and prevents the retainer 10 from rotating.

The main body 12 is formed by integral press molding to form an outer ring portion 13, a center portion 14, and a plurality of radial support portions 15 extending from the center portion 14 to the ring portion 13, and is attached to the outer ring 11 by welding or other means. Fixed. Each of the radial support portions 15 is provided with an insulator support tongue piece 16 protruding from the tongue piece 1 .
6 is bent so as to wrap around the insulator 17 to fix the insulator 17 to the support portion 15. As shown in FIG. The insulator 17 has a plurality of heater wire support grooves 18 into which heater wires are fitted and supported, and the heater wires 5 are fitted into and held within these support grooves 18 . Radial support part 15
is an oxide film (alumina) to improve insulation.
It is preferable to coat the Note that 19 is a ventilation hole protruding from the central portion 14 in order to increase the aperture ratio and suppress exhaust pressure.

Therefore, in the present exhaust particulate trap having the above configuration, the heater wire 5 is supported by the insulator 17 of the retainer 10, so even if the heater wire 5 is exposed to high temperatures and is subjected to vehicle vibration, the heater wire 5 can be easily moved. It will not be deformed or lifted off the filter element 2. Therefore, after the amount of particulate matter collected by the filter element 2 reaches a certain value, the heater wire 5 is energized to reliably ignite and burn it. No ignition failure or heating temperature distribution failure occurs.

6 and 7 show other embodiments of the present invention. In this embodiment, the retainer 20 is formed of an outer ring 21, a plurality of triangular strip plates 22 inscribed in the ring 21 and fixed by welding, and a plurality of annular supporting members 23 having different diameters connecting the strip plates 22. Each leg portion of the strip plate 22 constitutes a radial support portion 24. heater wire 5
The insulator 17 having the support groove 18 has a metal cover 25
This metal cover 25 is welded and fixed to the support portion 24 using tongue pieces 26 protruding from the support portion 24 in the radial direction. Note that the band plate 22 and the annular support member 23 are fixed by welding after their notch grooves 27 and 28 are engaged with each other.

Similar to the first embodiment, this embodiment also allows reliable support of the heater wire.

As is clear from the above description, the shape of the retainer used in the present invention is not limited to that of the illustrated embodiment; the purpose is to press the heater wire against the front end surface of the filter element from the outside, so that the shape of the retainer is not limited to the shape of the retainer used in the present invention. Any material may be used as long as the opening to be formed can be formed.

In this way, the present invention presses the heater wire located on the front end surface of the filter element against the filter element from the outside using a retainer, fixes this retainer to the trap body, and then inserts and holds the heater wire into the insulator fixed to this retainer. Since the wire support groove is provided, deformation and lifting of the heater wire can be prevented, thereby eliminating ignition failure and heating temperature distribution failure. Furthermore, since the heater wire is held by the insulator, good electrical insulation can be obtained over a long period of time.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view showing an embodiment of the exhaust particulate trap according to the present invention, Fig. 2 is a left side view of Fig. 1, and Fig. 3 is an enlarged view of the connection between the heater wire and the electrode section. , Figure 4 is an exploded perspective view of the retainer, and Figure 5 is an exploded perspective view of the retainer.
The figure is a sectional view taken along the line V-V in FIG. 2, and FIG. 6 is a side view similar to FIG. 2 showing another embodiment of the present invention.
FIG. 7 is a perspective view of the main parts of the retainer shown in FIG. 6. 2... Filter element, 5... Heater wire,
10, 20... Retainer, 15, 24... Radial support portion, 17... Insulator, 18... Heater wire support groove.

Claims (1)

[Scope of utility model registration request] In an exhaust particulate trap, in which a heater wire that ignites and burns the collected particulate matter is closely attached to a filter element that collects the particulate matter contained in the exhaust gas of an internal combustion engine, the heater wire is fixed to the particulate trap body. An exhaust patty cullate characterized in that the insulator is pressed against a filter element by a retainer, and has an insulator fixed to the retainer, which has an opening for forming an exhaust gas passage and a heater wire support groove into which a heater wire is inserted and held. Trap.