JPS58158310A - Particulate purifier in exhaust gas of internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve ignition performance of a collected particulate by means of a heating device and to make burning of the particulate not to be blown off by an exhaust gas flow, by providing a heating device which ignites and burns and a valve which is provided within a bypass and opens and closes the bypass. CONSTITUTION:At the time of collection of a particulate by a filter component material 5, a duct 40b is kept closed by a reed valve 8. The particulate in exhaust gas to be discharged through an exhaust gas collecting pipe 2 and an exhaust pipe 3 of an internal-combustion engine 1 is collected according as it passes through the filter component material 5. When a pile of the particulates comes to a predetermined measure, a signal is sent to a valve actuation device 15 from a control circuit 12, the duct 40b is closed by actuating the reed valve 8 and an exhaust gas flow to a duct of a filter side partitioned by a separation plate 7 is reduced. At the same time, an electric heater 6 provided on the filter component mateial 5 is electrified and heated at red heat, through which burning is started by heating the particulates collected around the heater.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an exhaust gas particulate purification system that collects particulates in exhaust gas emitted from internal combustion engines of automobiles, etc., and burns them using electric heating means to purify the exhaust gas. It is related to the device.

In order to collect particulates such as carbon particles contained in exhaust gas emitted from internal combustion engines, particulate collection devices incorporating a filter member such as a hexalamic honeycomb structure or ceramic foam have been proposed. ing. In these devices, as particulates accumulate on the filter member, the ventilation resistance of the filter member increases, leading to a decrease in the output of the engine, and the accumulated particulates fall off, reducing the filter function. For this reason, a heating means is attached to the filter member as a regeneration means for periodically removing the particulates accumulated on the filter member and regenerating the function of the filter member to the state before collecting the particulates.
A method of heating and burning the collected particulates has been proposed. However, under normal driving conditions, the exhaust gas temperature is lower than the ignition point of carbon particles, so the heat source is cooled by the exhaust gas, preventing the particles from igniting, and even if they are ignited, they are blown out by the exhaust gas flow. or Therefore, the operating conditions under which it can be reliably regenerated are extremely limited.

As a means to improve the ignitability of particulates and to prevent them from being blown out during combustion, the exhaust gas passage connected to the internal combustion engine is divided into two, a filter member is provided in each passage, and the exhaust gas passage of the filter member is A method has been proposed in which a flow path switching pulp is provided on the gas upstream side or the downstream side, the exhaust gas is selectively guided to one path, and the filter member installed in the path through which the exhaust gas does not flow during pulp operation is heated and regenerated. ing. However, with this method, when one passage is closed, the pressure loss C or less at the filter member of the capacity passage (hereinafter referred to as pressure loss) is more than doubled, and the flow rate of the exhaust gas is also approximately doubled. An increase in pressure drop worsens the driving feeling and has a negative impact on the engine's output.In addition, due to the increase in flow velocity, particulates collected in the filter member may be blown away depending on the operating conditions at the time of valve switching. , the filter function may deteriorate.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an exhaust gas particulate purification device that has a simple and compact structure, has good ignition properties for collected particulates by a heating means, and does not cause the combustion of particulates to be blown out by the exhaust gas flow. purpose.

The exhaust gas particle purification device of the present invention which achieves the above object basically includes a filter member installed in the exhaust gas passage of an internal combustion engine to attach and collect particulates in the exhaust gas, and an exhaust gas upstream side of the filter member. The upstream and downstream sides of the filter member in the exhaust gas passage are communicated with an electric heating means that is installed on or near the end face and generates heat when energized to ignite and burn the collected particulates, and when it is fully opened, most of the exhaust gas is It consists of a bypass passage with low ventilation resistance that allows the flow to flow without passing through the filter member, and an opening/closing pulp that is installed in the bypass passage and controls the amount of exhaust gas flowing into the filter member by opening and closing the bypass passage.

Hereinafter, the present invention will be explained with reference to illustrated embodiments.

FIG. 1 is a configuration diagram of an exhaust system of an internal combustion engine equipped with an exhaust gas particulate purification device according to the present invention.

1 is an internal combustion engine such as a diesel engine, 2 is an exhaust manifold pipe, and 5 is an internal combustion engine such as a diesel engine.
is an exhaust pipe, and A is a particulate purification device installed in the middle of the exhaust pipe.

The purification device A includes a filter member storage container 4, a particulate-collecting filter member 5, and a plurality of electric heaters 6 that are brought into close contact with the exhaust gas inflow @ (upstream side) end face of the filter member 5. 7 is a separator plate that divides the exhaust gas flow path, and 8 is an exhaust gas flow path opening/closing valve that controls the inflow of exhaust gas into the divided flow path (bypass passage). 9 is a differential pressure sensor for measuring the differential pressure on the upstream side and downstream side of the filter member 5 to detect pressure loss; 10 is a temperature sensor for detecting the exhaust gas temperature on the downstream side of the filter member 5; 11 is the engine 1; This is a rotation speed sensor that detects the rotation speed of the engine. 12 is for calculating the degree of particulate accumulation on the filter member 5 based on the outputs of the differential pressure sensor 9, filtration rate sensor 10, and rotation speed sensor 11, and operating the electric heater 6 and opening/closing valve 8 when the degree of accumulation exceeds a predetermined value. This is a control circuit that generates an output signal. 15 is a battery; 14 is a heater operating switch that receives an output signal from the control circuit 12 and supplies power from the battery 15 to the electric heater 6; 15 is a flow path opening/closing valve 8 that receives an output signal from the control circuit 12; It is a pulp actuation device that operates.

The flow path 40b has much lower ventilation resistance than the filter member 5, and has a cross-sectional area such that most of the exhaust gas flows in when the on-off valve 8 is fully opened.

In the above configuration, the open/close pulp 8 keeps the flow path 40b closed when the filter member 5 collects particulates. Particulates in the exhaust gas discharged through the exhaust manifold pipe 2 and exhaust pipe 5 of the internal combustion engine 1 are collected as they pass through the filter member 5. As the collection progresses, the ventilation resistance of the filter member 5 gradually increases, and this is detected by the differential pressure sensor 9. This differential pressure varies greatly depending on the exhaust gas temperature and engine speed, so by detecting each with the temperature sensor 10 and the engine speed sensor 11 and removing these influences, the true filter ventilation resistance, that is, the particulate matter The degree of accumulation can be determined. When a predetermined accumulation level is reached (a signal is sent from the control circuit 12 to the valve operating device 15, the on-off valve 8 is operated and the flow path 4 is
0b is opened to reduce the exhaust gas flow to the filter-side flow path partitioned by the separator 7. That is, by opening the flow path 40b, most of the exhaust gas flows into the flow path 40b, which has much less pressure loss than the filter member 5. At the same time, the electric heater 6 provided in the filter member 5 is energized, and the heater becomes red hot, heating the particulates collected around it and starting combustion.The fire spreads to the downstream side and the collected particulates are Burning and oozing. Then, the end of the regeneration is confirmed by the temperature sensor f10.

Furthermore, if the filter is regenerated by the above operation when the engine speed is low, almost no exhaust gas will flow into the filter member,
For this reason, there may be cases where the oxygen required for combustion cannot be supplied and regeneration is not completed completely. Therefore, rotation speed sensor 1
1 to read the rotation speed, /( at various rotation speeds)
By setting the opening degree of the valve, an appropriate flow rate of exhaust gas can flow into the filter member 5 during filter regeneration regardless of the rotation speed.

After the combustion is completed, the flow path 40b is shut off by the on-off valve 8 and operated so that almost all of the exhaust gas passes through the filter member 5, and the collection of particulates by the filter member 5 is resumed.

@2, sWA and FIG. 4 show a first embodiment of the exhaust gas particulate infiltration device according to the present invention.

A cylindrical container 4 with an elliptical cross section is partitioned by a partition plate 7 to form exhaust gas flow paths 40m and 40b. A filter member 5 is housed in the flow path 40a, and the filter member 5 is elastically supported by a wire net 41 and a seal member 42. The filter member 5 is made of ceramic foam, for example.

An opening/closing valve 8 is rotatably supported in the middle of the exhaust gas passage (bypass passage) 40b, and the opening/closing or opening degree of the passage 40b is controlled by twenty rotations.

A nichrome wire heater 6 is installed on the end face of the upstream coupler of the filter member 5.
is installed. The heater 6 is fixed by a ceramic honeycomb body 60 provided so as to cover them. The ceramic honeycomb body 60 serves as a heater holding member and a heat insulator.

In this device, the on-off valve 8 first shuts off the flow path 40b during collection, and the flow path 408@ where the filter member 5 is provided.
(
Figure 2). As a result, the exhaust gas flows into the filter member 5, particulates are collected, and the exhaust gas flows out from the filter member 5.

When the amount of particles collected by the filter member 5 reaches a predetermined value, the on-off valve 6 rotates to open the flow path 4Qb, whereby most of the exhaust gas flows into the flow path 40b (FIG. 4). At the same time, the heater 6 is energized and the particulates collected near the end face of the filter member 5 are ignited. The combustion then spreads to the collected fine particles on the downstream side, and the filter member 5 is regenerated. When the regeneration is completed, the on-off valve 8 rotates to shut off the flow path 4Qb, allowing almost the entire amount of exhaust gas to flow into the filter member 5 again, and resuming the collection. When the heater 6 is energized and regenerated, the amount of exhaust gas flowing into the filter member 5 is significantly reduced, and therefore the heater 6 is not cooled by the exhaust gas, and can be effectively and efficiently used with a small amount of thermal energy. It has an excellent practical effect of being able to reliably ignite fine particles.

FIGS. 5 and 6 show a second embodiment.

The exhaust gas passage 40b is formed completely separate from the container body 4, and an on-off valve 8 is installed in this passage 40b. The rest of the structure and operation are substantially the same as the first embodiment. The flow path 40b can be formed with only slight processing on the existing filter holding container, which is advantageous in manufacturing.
FIGS. 7 and 8 show a third embodiment, in which the passage 40b has a crescent-shaped cross section. Since the area of the partition wall 70 that partitions the flow path 401.40b is large, the heat of the exhaust gas flowing through the flow path 40b during regeneration is easily conducted to the filter member 5, which is thermally advantageous.

9, 10, and 11 show a fourth embodiment, in which a flow path 40 for holding a filter member 5 and an opening/closing pulp 8 are shown.
A container 4 having a flow path 40b with a flow path 40b is installed at the outlet of the exhaust manifold pipe 2. Flow path 40a, Job is separator 7
It is separated by The structure marked with * is substantially the same as that of the first embodiment, and the same members are indicated by the same symbols.

In this embodiment, since the particulate collection mechanism is located directly below the exhaust manifold, the exhaust gas temperature is high and the filter member is preheated, which is thermally advantageous during regeneration.

Moreover, the container can also be made into Convacuum F.

FIGS. 12 and 13 show a fifth embodiment in which a particulate purification device is also provided directly below the exhaust manifold 2, and the on-off valve 8
The exhaust gas flow path 40b equipped with an on-off valve is provided adjacent to the outer wall of the container body 4.In addition, in the sixth embodiment shown in FIG. The body is made up of pipes.

In each of the embodiments described above, in addition to the on-off valve 6, a butterfly valve that can open and close the channel 40 provided with the filter member 5 may be installed on the upstream or downstream side of the filter member 5. .

Thereby, it becomes possible to appropriately adjust the amount of exhaust gas flowing into the filter member 5 according to the operating conditions. For example, when the filter is regenerated when the engine rotates at high speed, the amount of exhaust gas increases, so even if the opening/closing valve of the flow path 40b is fully opened, the amount of exhaust gas flowing into the filter member 5 increases. In this case, by restricting the inflow of exhaust gas into the filter member to a small amount using the butterfly valve, the particulate ignition performance of the filter member can be maintained more reliably.

As explained above, the present invention includes a filter member equipped with a heating means, a bypass passage that allows some exhaust gas to flow into the filter member but bypasses most of the exhaust gas, and controls the opening and closing of the bypass passage. When the on-off valve is closed, the entire amount of exhaust gas flows through the filter member and collects particulates. However, when the filter member is regenerated, most of the exhaust gas flows through the bypass passage by opening the on-off valve, but a small amount of exhaust gas also flows into the filter member, so it is necessary to burn the collected particulates using the heating means. Oxygen is supplied. However, since the amount of exhaust gas flowing into the filter member is controlled to a small amount, there is no possibility that the exhaust gas will overwhelm the heat of the heating means and cause ignition.In this way, the present invention has a compact structure. The filter member can efficiently collect particulates in exhaust gas and ignite and burn the collected particulates. The present invention is applicable to purifying carbon particulates contained in exhaust gas of internal combustion engines, particularly diesel engines. It is extremely effective.

t [Brief explanation of ffi Figures 1 to 4 show the first embodiment.
IA is a configuration diagram of the exhaust system of an internal combustion engine equipped with a particulate collector, Figure 2 is a longitudinal cross-sectional view of the particulate collector showing the state during particulate collection, and Figure 5 shows the layers in Figure 2. -A straight sectional view, Fig. 4 is a longitudinal sectional view of the particulate collection device, showing the state at the time of filter member regeneration, and Figs. 5 and 6 show the second embodiment. A vertical cross-sectional view of the particulate collector, Figure 4 is a cross-sectional view taken along the line T in Figure 5, and Figures 7 and 8 show the fifth embodiment. 8 is a sectional view taken along the line ■-■ in FIG. 7, FIGS. 9 to 11' show the fourth embodiment, FIG. 9 is a configuration diagram of the exhaust system, and FIG. 11 is a sectional view taken along the line 1-1 in FIG. 10, FIGS. 12 and 15 show the fifth embodiment, and FIG. FIG. 15 is a longitudinal sectional view of the exhaust gas particulate purification device, FIG. 15 is a sectional view taken along the line II-II in FIG. 12, and FIG. 14 is a longitudinal sectional view of the exhaust gas particulate purification device of the second embodiment.

1... Internal combustion engine main body 2... Exhaust manifold pipe 5... Exhaust pipe A... Exhaust gas image particle purification device 40b... Bypass passage 5... Filter member 6... Electric heater '57 Figure 6'! J7 @
y B circle Figure 9

Claims (3)

[Claims] (1) A filter member installed in the exhaust gas passage of an internal combustion engine to collect particulates in the exhaust gas, and a filter member installed at or near the exhaust gas upstream end face of the filter member to heat the particulates collected by the filter member. An electric heating means for causing combustion, a bypass passage that connects the upstream side and the downstream side of the filter member of the exhaust gas passage and allows passage of most of the exhaust gas with ventilation resistance lower than that of the filter member, and a bypass passage provided in the bypass passage. is an exhaust gas particulate purification device for internal combustion engines equipped with an on-off valve that opens and closes a bypass passage. (2) The exhaust gas particulate purification device for an internal combustion engine according to claim 1, wherein the opening/closing valve is adjustable in opening degree to control the amount of exhaust gas flowing into the filter member. (3) The exhaust gas passage section in which the filter member is installed, the bypass passage, and the on-off valve are housed in a substantially integrated container, and this is installed at the outlet of the exhaust manifold pipe. Exhaust gas particulate purification device for internal combustion engines.