JPH0631121A - Honeycomb filter - Google Patents

Abstract

PURPOSE:To provide a honeycomb filter where the regeneration of the filter is rapidly and surely realized by relatively simple operation. CONSTITUTION:A honeycomb filter 1 used in an exhaust purifier of vehicles, etc., consists of a casing part 2 made of porous ceramics, an upstream side cover part 3 and downstream side cover part 4 made of omniazimuth shape memory alloy. In the upstream side cover part 3 and downstream side cover part 4 having upstream side guide holes 3a and downstream side guide holes 4a communicating with through holes 2a of the casing part 2 respectively, valve discs 9 memorizing the closed state and open state of the upstream side guide holes 3a and the downstream side holes 4a are formed in one body. When the valve discs 9 are in the closed state, exhaust introduced from the upstream side guide holes 3a is passed through a partition setting apart the adjacent through holes 2a to collect fine particles in the exhaust. And when the valve discs 9 are in the open state, compressed air is blown in from the filter upstream side, causing the fine particles deposited on the partition to be blown off to the filter downstream side, allowing the honeycomb filter 1 to be regenerated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a honeycomb filter for collecting fine particles and the like in a fluid, and is applied to, for example, an exhaust purification device of a diesel engine.

[0002]

2. Description of the Related Art Conventionally, a honeycomb filter made of porous ceramic is known as a filter for purifying exhaust gas emitted from an internal combustion engine for vehicle running. This type of filter collects particulates such as particulates contained in the exhaust gas by a partition formed inside the filter. When the amount of fine particles collected inside the filter reaches a predetermined amount, for example, the filter is heated by burning the fine particles, or compressed air is sent from the downstream side of the filter to blow the fine particles to regenerate the filter. Let

[0003]

However, according to such a conventional honeycomb filter, when the filter is regenerated, if the collected fine particles are heated and burned, the regeneration time tends to be relatively long, and the downstream side of the filter is liable to be relatively long. If compressed air is blown in more, fine particles cannot be sufficiently removed, and if the filter is used for a long time, the regeneration efficiency of the filter is lowered.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a honeycomb filter in which regeneration of the filter can be realized quickly and reliably by a relatively simple operation. .

[0005]

A honeycomb filter according to the present invention for solving the above-mentioned problems includes a large number of through holes extending axially through partition walls having air permeability, one end of the through holes and the through holes. A valve body is provided at the other end of the through hole adjacent to the hole so as to be opened and closed, and the valve body is made of a shape memory alloy that opens and closes the through hole with a predetermined temperature as a boundary.

[0006]

According to the honeycomb filter of the present invention, the shape of the valve element provided in the through hole changes to the closed state when the temperature of the filter is high, for example. At this time, the fine particles in the fluid are collected by the partition wall made of a porous body. Also, when the temperature of the filter is low,
When the shape of the valve body changes to the open state, the fine particles collected in the partition wall are discharged to the downstream side without passing through the partition wall by the fluid flowing through the through hole.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a honeycomb filter according to an embodiment of the present invention.
As shown in FIG. As shown in FIG. 2, a honeycomb filter 1 used in an exhaust gas purifying apparatus for a vehicle or the like includes a tubular body 2 made of a multi-hard ceramic such as cordierite or mullite,
It is composed of an upstream lid 3 and a downstream lid 4 made of an omnidirectional shape memory alloy such as Ti-Ni (50.5 to 52 at%). As shown in FIGS. 1 and 3, a rectangular parallelepiped cylindrical body 2
Has a large number of through holes 2a having a square cross section, and the partition wall 6 which partitions the through holes 2a adjacent to each other can collect the fine particles in the exhaust gas. The upstream lid 3 and the downstream lid 4 are
An upstream guide hole 3a and a downstream guide hole 4a are provided at positions communicating with the respective through holes 2a. The exhaust gas discharged from the internal combustion engine passes through the upstream guide hole 3a, the through hole 2a, and the downstream guide hole 4a, and is introduced into the muffler or the like.

Upstream guide hole 3a and downstream guide hole 4a
Is provided with a valve body 9 made of an omnidirectional shape memory alloy so as to form a checkerboard pattern when the honeycomb filter 1 is viewed from the exhaust gas flow passage direction. The valve body 9 is integrally provided with the upstream side cover body 3 and the downstream side cover body 4, and is formed in an area substantially equal to the hole diameters of the upstream side guide hole 3a and the downstream side guide hole 4a. As shown in FIG. 3, regarding the position of the valve body 9, when focusing on one through hole 2a, the valve body 9 is arranged in one of the upstream guide hole 3a or the downstream guide hole 4a communicating with the through hole 2a. To be done.

As shown in FIG. 1, the valve body 9 is shown in FIG.
Two types of states are stored: an open state at a low temperature as shown in FIG. 1 and a closed state at a high temperature as shown in FIG. The opening / closing angle of the valve body 9 is set to, for example, 90 ° and 0 ° with respect to the end surface of the lid body in the exhaust gas flow path direction, and the operating temperature of the valve body 9 is set to, for example, about 60 ° C. As a result, when the temperature is low, the valve body 9 opens, so that the upstream guide hole 3a, the through hole 2a, the partition wall 6, the through hole 2a, and the downstream guide hole 4a communicate from the upstream side to the downstream side of the honeycomb filter 1, When the temperature is high, the valve body 9 is closed, so that communication between the upstream guide hole 3a, the through hole 2a, and the downstream guide hole 4a is blocked.

When the honeycomb filter 1 reaches the operating temperature of the valve body 9 due to the heat of the exhaust gas during operation of the internal combustion engine, the valve body 9 changes to the closed state. Then, as shown in FIG.
The exhaust gas introduced from the upstream guide hole 3a passes through the partition wall 6 that partitions the adjacent through holes 2a, and is discharged from the downstream guide hole 4a. At this time, fine particles such as soot, dust, and particulates in the exhaust gas are collected by the partition wall 6 and deposited on the surface of the partition wall 6.

When the operation of the internal combustion engine is stopped, the temperature of the honeycomb filter 1 decreases and the valve body 9 returns to the operating temperature again. At this time, the valve body 9 changes to an open state. And
When the honeycomb filter 1 is regenerated, if the compressed air is blown from the upstream side of the filter when the valve body 9 is in the open state, the partition wall 6
The fine particles attached to the through holes 2a and the downstream guide holes 4a.
And is blown off to the downstream side of the filter. As a result, the honeycomb filter 1 is instantly regenerated.

The fine particles remaining on the partition wall 6 may be burned by a heater or the like. In this case, since the air permeability of the partition wall 6 is restored, the fine particles are surely burned in a short time. Further, even if the through holes 2a are washed with water from the upstream side to the downstream side of the filter, the fine particles can be removed and the honeycomb filter 1 can be regenerated. As described above, according to the honeycomb filter of the above-described embodiment, the fine particles attached to the partition walls 6 can be directly discharged to the downstream side of the filter. For this reason,
The regeneration efficiency of the filter can be significantly improved.

In the above-mentioned embodiment, the filter is a rectangular parallelepiped cylinder, but the present invention may have another shape such as a cylinder. Further, in the above-described embodiment, the shape memory alloy forming the valve body 9 has Ti-Ni (50.5 to 52 at%).
Although used, other shape memory alloys may be used as long as they can store two states. Furthermore, the temperature of the valve body 9 may be adjusted by energizing the upstream side cover body 3 and the downstream side cover body 4 to control the open state and the closed state of the valve body 9.

[0014]

As described above, according to the honeycomb filter of the present invention, by providing the shape memory alloy on the filter end face, the filter function and the simple flow path function can be selectively used, and the filter can be easily and surely regenerated. Since it can be performed, there is an effect that the durability and reliability of the filter can be significantly improved.

[Brief description of drawings]

FIG. 1 is a partial perspective view showing a honeycomb filter according to an embodiment of the present invention.

FIG. 2 is a partial perspective view showing a honeycomb filter according to an embodiment of the present invention.

FIG. 3 is a vertical sectional view showing a honeycomb filter according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Honeycomb filter 2 Cylindrical body 2a Through hole 3 Upstream side cover body (1st cover body) 3a Upstream side guide hole (1st guide hole) 4 Downstream side cover body (2nd cover body) 4a Downstream side guide hole (2nd) Guide hole) 9 valve body

Claims (1)

[Claims] 1. A large number of through holes that extend through the partition wall in the axial direction by a partition having air permeability, and a valve body that is openably and closably provided at one end of the through hole and the other end of the through hole adjacent to the through hole. And a valve body made of a shape memory alloy that opens and closes the through hole with a predetermined temperature as a boundary.