JPS5876122A - Apparatus for collecting fine particles - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a particulate collection device for collecting particulates in engine exhaust gas, particularly particulates mainly composed of carbon, and purifying the exhaust gas.

Conventionally, this type of device has two or two filters made of fibers made of heat-resistant material installed in parallel along the exhaust line, and each of these filters is equipped with a heating means of about 10,000 feet. It is known that one filter collects particulates in exhaust gas while the other filter is regenerated by heating means, in other words, the collected particulates are burned and purified.However, this conventional type has two filters. The problem is that the device becomes large and the heating means also requires a large amount of heat.

In order to solve this kind of melting point problem, upstream inspection of the filter is provided with rotatable exhaust gas control means that covers 173 mm or less of the area of the exhaust gas introduction part of the filter, and a part of the filter covered with this exhaust gas control means is installed. An apparatus has been proposed that is equipped with a heating means for heating the exhaust gas, and sequentially regenerates a portion of the filter covered by the exhaust gas control means as the exhaust gas control means rotates.

However, when regenerating a filter, even if it is simply heated with a heating means, ignition and twisting will not occur in the absence of oxygen.For this reason, it is possible to introduce surplus oxygen from the exhaust gas.For example, if the exhaust gas control means is 1mm Countermeasures include forming holes. However, it has been found that if the inlet hole is narrow, it will easily become clogged with carbide (soot), and if the inverse C2 is too wide, the amount of exhaust gas flowing into the filter regeneration section will be excessive, making ignition impossible. Ta.

The present invention has been made based on the above-mentioned features 11-, in which the exhaust gas control means C2 has a relatively thick inlet hole 4; a part of the filter is formed to prevent clogging and to be regenerated; The purpose of the present invention is to provide a particulate collection device that can effectively regenerate the filter so that the excess exhaust gas bypasses the filter and escapes to the downstream side of the exhaust gas.

The details of the present invention will be explained below based on illustrated embodiments.

1 to 4 show a 9!41 embodiment of the present invention,
%1 In the diagram, exhaust gas discharged from a diesel engine of a vehicle (not shown) is introduced through an inlet section 1, and after being purified by collecting particulates in a filter 2, it is exhausted through an outlet section 3.

The inlet part 1 is constituted by an inlet part case 1m made of gold IF4, and the downstream side is connected to an exhaust pipe (not shown), and the C2 downstream side is connected to a metal housing 20. The exit part 3 is an exit part case Ja made of gold PA (
The upstream side is the housing 20.
1-fi is connected, and C2 is connected to an exhaust pipe (not shown) on the downstream side.

The above-mentioned filter 2 is accommodated in the housing 20. As shown in Figure 2, the filter 2 is constructed by supporting a ceramic filter element 23 in a heat-insulating ceramic container 2. The container 21 has a peripheral wall 21m, a radial partition '!!!21b, and a central part 21.
C is integrally formed with C, and therefore, 26 fan-shaped hollow portions are formed in the radial direction. The filter element 23 is filled in these hollow portions. The container 21 is fitted with the housing 20 (two fittings), and the peripheral edges of both ends of the container 21 are connected to the housing 2.
0 by metal ribs 25.25.

A partition plate 4 corresponding to the exhaust gas control means (2) of the present invention is arranged on the upstream side of such a filter 2.The partition plate 4 is divided into six parts in the filter 2 as shown in FIG. The partition plate 4 (:) forms a fan-shape facing one of the filter elements 23, and has at least one exhaust gas introduction hole 5. The shaft 6 is made of gold*a and supports the partition plate 4 with a nut IC. The support plate 8 is rotatably held by the support plate 8, and the support plate 8 is fixed to the inlet case 1.The shaft 6 is connected to the latch gear 9m shown in FIG. The latch gear 9m has a C2 shape so that it is rotated by the movement of the ratchet 9b.Therefore, the latch gear 9m
The ratchet 9b constitutes the rotating means of the present invention. Note that 9c is a return spring.

A heating means is attached to the partition plate 4.

That is, the inner surface of the partition plate 4 facing the filter 2 (- indicates that a porous insulator 11 is connected to the insulator 11 through an insulator 12, and an electric heater 13 is installed on the surface of the porous insulator 11 facing the filter 2. It is fixed by screws 14. Note that the upper heater 3 is connected to a lead wire 15, and this lead wire 15 is conducted to the outside S through a through hole 61 formed in the shaft 6. .

A bypass passage 18 is formed along the axial direction in the center 216 of the container 21 (second part) of the filter 2 mentioned above. It communicates with the space formed by the upstream side surface (2) and the downstream end is open.

The operation of the first embodiment as described above will be explained.

When the engine is driven and exhaust gas containing particulates is introduced from the inlet 1, the exhaust gas mainly passes through the filter cake 23 in the area excluding the part covered by the partition plate 4, and during this passage, the particulates in the exhaust gas are Filter element 236: Captured. For example, when traveling a short distance, the ratchet 9b of the ratchet mechanism is reciprocated by the control device (not shown) to move the shaft 6 and the partition plate 4 176 times, and the 1/6 area of the filter j (= It is cut off from the flow.The rotation 1 of the partition plate 4:
3 are also rotated together. In this state, when the heater IJIg is energized from a battery (not shown) via a switch, the heater 13 generates heat. At this time, the exhaust gas containing excess oxygen is led to the portion C1 covered by the partition plate 4 from the exhaust gas introduction hole 5 opened in the partition plate 4,
A part of it passes through the porous insulator 11, is heated by the heater 13C, and is introduced into the filter confectionery 23 (2), which is shielded from the exhaust gas.Furthermore, the filter element 23 is also heated by the heater 13C. , the filter confectionery 231: The collected particulates are purified by combustion.

Since the filter element 23 is made of foamed ceramic, fine particles evenly adhere to the filter confectionery 23 (=).Also, the filter confectionery 21 (second is combustion: since an appropriate amount of exhaust gas flows, regeneration heat is effectively transferred to the upstream side). As a result, the area of the regeneration section can be expanded from the upstream side to the downstream side 1. Therefore, the fine particles collected by the filter element 23 react with the heat from the heater 13 and the heat from the chemical reaction, and :o O, and water vapor, which is discharged toward the outlet section 35. Therefore, the filter element 23 is efficiently regenerated.

Therefore, it is desirable that the introduction hole 5 has a large opening area since the introduction hole 5 is likely to be clogged if the opening area of the partition plate 4 (:) is made small.
2) Then, the filter element 23 is regenerated (2) The exhaust gas in excess of the required amount is removed from the area t:f covered by the partition plate 4.
Filter confectionery 231: Since a large amount of exhaust gas is mixed in, the regeneration efficiency decreases. However, in this practical example, since the bypass passage 18 is formed in the center part 21c of the filter container 21, a part of the exhaust gas discharged to the part covered by the partition plate 4 passes through this bypass passage I8 to the outlet. 3 will be let go. That is, filter element 2
Regeneration of S (exhaust gas in excess of the required amount of exhaust gas is discharged without passing through the filter confectionery 23.

As a result, the opening area of the introduction hole 5 of the partition plate 4 can be increased to prevent clogging, and the filter element 23 (
Second, since an amount of exhaust gas suitable for regeneration can be supplied, the filter confectionery 23 can be regenerated effectively.

After the 176 filter collectors 23 have been regenerated as described above, if another filter element 23 becomes clogged, the same operation as above is repeated to sequentially regenerate the entire filter 2, and the entire filter 2 is regenerated as a whole. It always maintains good collection performance.

In the first embodiment, the filter 2 is divided into six regions, one of which is covered with the partition plate 4. However, in order to downsize the device, it is necessary to divide the filter 2 into at least three (two) regions. The heater 13 is not necessarily connected to the partition plate 4.
(=What is installed is a heater in each area of the divided filter 2 and a heater in each area of the divided filter 2, and selectively generates heat only by the heater that blows on the filter element in the part covered by the partition plate 4. Let's do it (you can also do it).

In addition, the material of the filter cluster 23 may be iron thread fibers such as quartz, glass, S10゜ZrO@, alumina, etc., in addition to stainless steel thread, etc., depending on the wire diameter and filling rate. etc. can be selected depending on the purpose (=).

Next, a second embodiment of the present invention will be described based on FIGS. 5 and 6.

As already explained in the first embodiment C2, the exhaust gas is introduced into the part covered by the partition plate 4 through the introduction hole 5 of the partition plate 4. If a gap occurs between the edge and the upstream end face of the filter 2, excess exhaust gas tends to flow in through this gap.Therefore, the opening edge of the partition plate 4 and the upstream end face of the filter 2 are separated. In the case of the first embodiment, the opening edge of the partition plate 4 is in sliding contact with the end surface of the filter container 21. However, since the filter container 21 is made of ceramic, and the partition plate 4 is made of gold Ik, the coefficients of thermal expansion are different, and therefore a gap is likely to be formed between the sliding surfaces of the partition &4 and the filter 2.

Therefore, in this embodiment C, the upstream end C of the filter 2:
A hollow member 51 made of gold lllium and having the shape shown in FIG. 6 and made of the same material as the partition plate 4 is arranged. In addition, the hollow punched flat plate 51 has a fan-shaped window 52 facing the filter element 23, and a through hole 5 through which the shaft 6 passes through the central part.
It has 3. Further, a plurality of exhaust gas passage holes 54 are formed around the periphery C2 of the negative passage hole 53. Such a hollow punched flat plate 51 is shown in FIG.
0 by means such as welding. The opening edge of the partition plate 4 is in sliding contact with the hollow punched flat plate 51. Therefore, since the partition plate 4 and the hollow punched flat plate 51 are made of the same material, they have the same coefficient of thermal expansion. Since no gaps are created between the sliding surfaces, undesired inflow of exhaust gas is prevented, flow rate control becomes more accurate, and wear between the two is reduced, improving durability.

Note that 55 is another hollow punched flat plate provided below the filter 2, and has almost the same shape as the inner wall punched flat plate 51 of the upstream part 011 described above.

However, the exhaust gas passage hole 54 is not formed in the hollow flat plate 55 on the downstream side. Also, 56.56 are hollow materials ^51.
55 and one surface of the filter 2 (a heat-resistant and elastic backing is interposed).

In addition, the shaft 6 has each hollow member h 5 J, s t;
A frame is freely rotatable in between, and the downstream hollow member 6ss
5F (: Therefore, extraction is prevented. This shaft 6 is connected to the center part 21 of the filter container 21.
The shaft 6 has a bypass passage of 18 yen and an outlet of 1 s.
A communication hole 58 communicating with J is formed.

In addition, a flange 59 is formed for regulating the mounting position of the partition plate 4 with high precision on the shaft 6 (:), and the partition plate 4 positioned by the flange 59 will not create a gap with respect to the upstream hollow member 651. Sliding contact is made.

The end of the shaft 6 is introduced into a gear case 60 yen (=), and this introduction part has a driven spur gear e1. The driven spur gear 61 is in mesh with a driving spur gear 62 (;
This driving spur gear 62 is connected to a motor 63. The motor 63 is electrically connected to a power source 64, and this energization is controlled by an electronic control device 65C such as a computer. The 111 child control device 65 detects the temperature of the regeneration section filter and controls the flow to the heater 13 (:), and also detects the range, engine speed, engine torque, exhaust differential pressure, mileage, etc. The shaft 6 and the partition plate 4 are controlled to rotate 176 times in response to the detection.

The second embodiment also has the same effect as the first embodiment, and in the special ζ two-piece m#pt+, the partition plate 4
The part covered with
... and is discharged to the outlet section 3 via the bypass passage 18 and the communication hole 58.

FIG. 7 shows a third embodiment of the present invention, which is a modification of the second embodiment shown in FIGS. 5 and 6-1. This thing has an elastic body 10 such as a sea coil spring between the nut 57 screwed onto the shaft 6 and the lower i-side hollow punch #fisz.
In this way, the partition plate 4 is pressed downward from the shaft 6 (-) and the hollow It is in close sliding contact with the hammer 51, and even if this sliding surface is abraded, it can be absorbed by the elastic body 20-2.

FIG. 8 shows a fourth embodiment of the present invention, in which the passage area of the bypass passage 18 is variable. A variable discharge port 80 is formed to communicate with the discharge port 80. 81 is a plunger that controls the opening area of the discharge port 80, and one end is connected to the communication hole 58 of the shaft 6 (= rotatable and axial direction 6: sliding). Movable ζ - inserted, the plunger 8
The other end of 1 is a cover 856 that can be rotated twice and can be displaced in the axial direction.
+: Pivotally supported. A driven side worm gear 82 is integrally provided on the plunger 81, and this worm gear 82 is meshed with two sliding worm gears 83. The drive side worm gear 83 is connected to the motor 844 in two directions.

The motor 84 is connected to a power source 64 (two W-connected).
4 to the motor 84 is controlled by an electronic control device 65 such as a computer.

The electronic control device 65 detects engine operating conditions such as exhaust gas temperature and intake negative pressure, and controls the energization from the II source 64 to the motor 84 in accordance with this detection.

In the fourth embodiment, the amount of exhaust gas released through the bypass passage 18 can be controlled by the intake negative pressure and the exhaust gas temperature. In other words, during general C: engine operation (:), the engine load and exhaust gas temperature almost correspond; as the load increases, the exhaust gas temperature increases, and as the load decreases, the exhaust gas temperature tends to decrease. Corresponds to the intake negative pressure. Therefore, when the intake negative pressure is large or the exhaust gas temperature is high, that is, when the engine load is large, the motor 84 is rotated and the drive side worm gear 83
．． The plunger 81 is moved in the direction indicated by the arrow via the driven worm gear 82. Then, since the opening area of the variable exhaust port 80 increases, the amount of exhaust gas released through the bypass passage 18 increases.

In addition, when the intake negative pressure is small or the exhaust gas temperature is low (=, the motor 84 is rotated in the opposite direction [the plunger 81 is moved in the direction opposite to the direction of arrow Ay5, thereby narrowing the opening area of the variable discharge port 80, - Reduce the amount of exhaust gas released via the bypass passage 18.

With such an action, the amount of exhaust gas to be supplied to the filter confectionery 23 to be regenerated is varied according to the exhaust gas temperature 62, so the thermal load on the heater 13 can be suppressed, and the regeneration C 2. Since the required temperature can be maintained at all times, effective regeneration can be performed.

Figure 9 shows a modification of the variable 11I means of the fourth embodiment. This is an example of s5. A plunger J1 that controls the opening area of the variable discharge port 80 is connected to a bimetal 90 and a diaphragm device 91. When the exhaust gas temperature rises, the bimetal 90 pushes the plunger 81 in the direction of the arrow to increase the opening area of the variable discharge port 80, increasing the amount of exhaust gas discharged, and increasing the amount of exhaust gas discharged. 1iiL
When the temperature decreases, the plunger 81 is moved in the opposite direction to the direction of the arrow ζ to reduce the amount of exhaust gas discharged from the variable exhaust port 80.

In the 10,000 diaphragm device 910, a diaphragm 94 is held between a main body 92 and a cover 93, and this diaphragm 94 is connected to a plunger 81 and is moved in a direction opposite to the direction of the arrow by a coil spring 95 (=
energized. A vacuum chamber 966 surrounded by a diaphragm 94 and a cover 93 is introduced via a conduit 97 with a negative pressure (for example, the negative pressure of a carburetor) that increases in accordance with the engine speed. The other chamber 98 is maintained at atmospheric pressure (1) through the atmospheric w4R port 99. Therefore, when the engine speed increases and the intake negative pressure increases, the diaphragm 94 is urged in the direction of the arrow, so the plunger 81 is also moved in the same direction, thereby increasing the opening area of the exhaust port 8'0 and increasing the amount of exhaust gas.

This W&5 embodiment also provides the same effects as the fourth embodiment.

Furthermore, FIG. 10 (2) shows a sixth embodiment of the present invention.

In this device, the variable emission control means in the fourth embodiment shown in FIG. 81 is installed on the upstream side. The shaft 6 has a variable hole 100 that communicates with the part covered by the partition plate 4, and this variable hole ZOO communicates with the bypass passage 18 (2) via a discharge hole 101. A granger 81m is inserted, and the opening area of the variable hole 100 is controlled by the plunger 81a.

In this case, the variable discharge control means and the rotation mechanism as the drive section for the partition plate 4 can be concentrated in one place, so that the structure can be made more compact.

In each of the embodiments (-), the electric heater 1s is constructed with a heat-generating wire, but the present invention can also be implemented with a ceramic heater, etc., and the energization time may be a fixed time, or a thermocouple, etc. It is also possible to use a control means that measures the temperature of the reproduction section and stops the current supply when the temperature rises above a certain temperature (for example, 900° C.).

Furthermore, in order to burn and purify the collected particulates, generally 600
Although a high temperature of 1.5 C or higher is required, for example, if an oxidation catalyst such as platinum is used, the activation temperature can be lowered and the amount of heat generated by the electric heater 13 can be lowered, thereby saving power consumption. Therefore, the filter 2 may be immersed in a chloroplatinic acid solution and then calcined to directly support the oxidation catalyst, or pellets supporting a platinum or platinum-rhodium oxidation catalyst may be placed inside the filter element 23 (1 level or upstream). The mixture may be concentrated on the upstream side end face of the filter element 23 (2, 2,
It is also possible to implement measures such as arranging a honeycomb structure supporting an oxidation catalyst.

In addition, the means for rotating the partition l8t4 relative to the filter 2 (two) is not limited to the ratchet e mechanism or motor described above, but may also utilize the forward movement of a diaphragm device, Geneva gear, etc., and the variable discharge port The means for varying 80 is not limited to a worm gear, a diaphragm, a bimetal, etc., and various modifications such as a hydraulic device can be applied.

As detailed above, the present invention forms an introduction hole for introducing the exhaust gas in the portion C1 covered by the exhaust gas control means in the exhaust gas control means that covers an area of 173 or less on the upstream side of the filter, and A bypass passage is formed that connects the portion covered by the control means and the downstream side of the filter without passing through the filter.Therefore, this allows the opening area of the introduction hole to be increased to prevent clogging, and By increasing the opening area of the introduction hole, even if excess exhaust gas tries to flow into the part of the filter that is being regenerated, the excess exhaust gas will be removed to the downstream side through the bypass passage without passing through the filter. , Filter regeneration (=A suitable amount of exhaust gas can be supplied to the filter (-), which has the advantage of enabling effective regeneration.

In addition, by providing a variable means for varying the passage area of the bypass passage according to the engine operating conditions, the amount of exhaust gas supplied to the filter to be regenerated can be varied according to the exhaust gas temperature, thereby suppressing the heat load on the heater. It is also possible to perform effective regeneration because the necessary temperature can be maintained at all times.

[Brief explanation of the drawing]

Figures 1 to 'WI4 show a first practical example of the present invention,
FIG. 1 is a longitudinal sectional view, FIG. 2 is a cross-sectional view of the filter, FIG. 3 is a bottom view of the partition plate and heater, and FIG. 4 is a sectional view of the rotating means. 5 and 6 show a second embodiment of the present invention, FIG. 5 being a longitudinal cross-sectional view and FIG. 6 being a cross-sectional view of a hollow punched plate. FIG. 7 is a longitudinal sectional view of the main parts showing the third embodiment of the present invention. FIG. 8 is a longitudinal sectional view showing a fourth embodiment of the present invention. FIG. 9 is a vertical cross-sectional view of the main part showing a fifth embodiment of the present invention. Further, FIG. 10 is a longitudinal sectional view showing a sixth embodiment of the present invention. 1... Inlet part, 2... Filter, 3... Outlet part. 4... Partition plate (exhaust gas control means), 5... Exhaust gas introduction hole, 13... Heater, 18... Bypass passage, 2
0... Housing, 21... Filter container, 23
...filter element, 9m, 9b...ratchet mechanism (rotating means), 80...variable discharge port, 81...plunger. Applicant's agent Takehiko E, patent attorney

Claims (2)

[Claims] (1) Inside the housing that forms the exhaust gas passage (= the disposed filter and the upstream side of this filter C is generally rotatable to the housing I: is attached and covers 173 or less of the area of the exhaust gas introduction part of the filter an exhaust gas control means, a rotating means for causing the exhaust gas control means to act together, a heating means for heating a part of the filter covered by the exhaust gas control means, and an exhaust gas control means C which is divided into two parts and covered by the exhaust gas control means. A particulate trap characterized by comprising an introduction hole for introducing upstream exhaust gas, and a bypass passage that connects the part covered with the exhaust gas to the upstream side 1 of the filter, bypassing the filter. Collection device/ (2) The particulate collection device according to claim 1, further comprising a variable means that changes the passage surface Wlt-lt-of the bypass passage according to engine conditions.