JP2000328926A - Diesel particulate filter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a rate for trapping particulate matter from the beginning of the trapping using a fiber filter and a honeycomb filter. SOLUTION: In the diesel particulate filter(DPF) device, the fiber filters 1, 2 are disposed in branch passages 11, 12, and a honeycomb filter 20 is disposed in an exhaust passage 18 downstream of the fiber filters 1, 2. Switch valves 9, 33 are disposed in exhaust passages 10, 18, respectively. A controller 25 operates the switch valve 33 such that, when the pressure of the exhaust gas passing through the fiber filter 1 or 2 is equal to or less than a predetermined value, the exhaust gas is directed to the honeycomb filter 20, by which particulate matter is trapped by the fiber filter 1 or 2 and the honeycomb filter 20. Meanwhile, when the pressure of the exhaust gas is equal to or greater than the predetermined value, the controller 25 controls so as to direct the exhaust gas to a bypass passage 19, by which the particulate matter is trapped only by the fiber filter 1 or 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diesel particulate filter in which particulate matter contained in exhaust gas discharged from an engine is collected by a filter, and the collected particulate matter is heated and incinerated to regenerate the filter. It relates to a filter device.

[0002]

Conventionally, the floating matter contained in the exhaust gas exhausted from an engine such as a diesel engine, carbon, smoke, HC, as a diesel particulate filter device for removing particulates matter consisting SO _X or the like, a ceramic A filter having a structure in which fibers are laminated and a filter having a honeycomb structure made of porous ceramics are known. This type of filter generally regenerates the filter by heating and burning the particulate material using a heat source when the particulate material is collected and the filter is clogged.

[0003] As a diesel particulate filter device for regenerating a filter, there is known a diesel particulate filter device in which a pair of filters are arranged in parallel in an exhaust gas passage in order to collect particulate matter contained in exhaust gas discharged from an engine. ing. The processing device that collects and regenerates particulates of particulate matter collects the particulate matter with one filter, and when the amount of the collected particulate matter exceeds a predetermined amount, switches the flow of exhaust gas to the other filter. The particulate matter collected by the filter is collected by heating, and the particulate matter collected by the filter is heated and incinerated to regenerate the filter.
279646, JP-A-8-313329).

[0004]

When the particulate matter collected by the filter is heated and incinerated in order to regenerate the filter in the diesel particulate filter device, as described above, the exhaust pipe upstream of the filter is used. From the exhaust gas to the filter in the regeneration state to heat and incinerate the particulate matter using oxygen in the exhaust gas, or introduce air from the outside to the filter in the regeneration state to heat and incinerate the particulate matter There is a need.

[0005] However, the fiber filter made of ceramic fiber material has a mat shape or a sheet shape in which nonwoven fabric and / or woven fiber materials are laminated, and completely traps particulate matter contained in exhaust gas. The trapping rate of particulate matter is about 60% to 80%. For example, in the fiber filter, as shown by the dotted line in FIG. 2, at the start of the collection, the gap between the fibers is large, and the collection rate of the particulate matter is 60%.
Approximately 80%, and after more than 20 minutes from the start of collection, a part of particulate matter is deposited between fibers,
The gap between the fibers becomes smaller and the collection rate increases to 98% or more. At that time, when one hour has elapsed from the start of collection of the particulate matter, the fiber filter has an exhaust resistance of 130 μm.
Since the pressure rises to about mmHg and a predetermined amount or more of particulate matter accumulates on the fiber filter, the switching valve is switched to control the exhaust gas to flow to another fiber filter.

Incidentally, a honeycomb filter having a honeycomb structure formed of ceramics or the like having small through-holes can trap 90% or more of particulate matter in exhaust gas. Is clogged with particulate matter in a short period of time and the filter itself must be replaced or switched to the other filter, which is not practical. For example, as shown in FIG. 3, the honeycomb filter has a small through hole in the honeycomb surface of the honeycomb structure at the start of collection, as shown in FIG. 3, so that the collection rate of the particulate matter is 90% or more. At the start, the through-holes were blocked due to the accumulation of particulate matter on the honeycomb surface, and after 20 minutes or more had elapsed from the start of collection, the exhaust resistance increased to about 60 mmHg.
Further, when 30 minutes or more have elapsed from the start of collection, the exhaust resistance rises to about 120 to 130 mmHg, so that exhaust gas cannot be flown to the honeycomb filter, and the switching valve is switched to flow exhaust gas to another honeycomb filter. Must be.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and it is an object of the present invention to provide a filter for maintaining particulate matter by a fiber filter and a honeycomb filter for starting particulate matter collection. To take advantage of the large collection rate and to simplify the structure, only one expensive honeycomb filter is used. Therefore, a dense honeycomb filter is placed downstream of the fiber filter. The present invention provides a diesel particulate filter device that can increase the collection rate by using a filter, and then, after a lapse of time, collects particulate matter only with a fiber filter and can make use of the sustained collection time. It is.

According to the present invention, there is provided a fiber filter disposed in an exhaust passage through which exhaust gas discharged from an engine flows to collect particulate matter in exhaust gas, and disposed in the exhaust passage downstream of the fiber filter. A dense honeycomb filter that collects the particulate matter, and a honeycomb filter that is switched to allow the exhaust gas to flow through one of the exhaust passage in which the honeycomb filter is installed and a bypass passage that bypasses the honeycomb filter. A first switching valve installed in the upstream exhaust passage, and flowing the exhaust gas to the honeycomb filter when the pressure of the exhaust gas passing through the fiber filter is equal to or lower than a predetermined value, and exhausting the exhaust gas when the pressure of the exhaust gas is equal to or higher than the predetermined value. A controller that controls switching of the first switching valve so that gas flows into the bypass passage. That on the diesel particulate filter device.

The fiber filter is provided in each of a pair of branch passages branched from the exhaust passage, and the exhaust passage is provided with a second switching valve that is switched to flow the exhaust gas to one of the branch passages. ing. Furthermore,
The controller is configured to cause the second fiber filter to flow the exhaust gas to the other fiber filter in a state where one of the fiber filters has collected the particulate matter in a predetermined amount or more.
Controls switching of the switching valve.

[0010] Further, the fiber filter is provided with a heater such as a wire net for heating and burning the collected particulate matter. Further, the honeycomb filter is made of a conductive material or provided with a heater in order to heat and incinerate the collected particulate matter.

The first switching valve is provided in a collecting pipe in which the branch passages downstream of the fiber filter are gathered, and the downstream of the collecting pipe is connected to an exhaust passage provided with the honeycomb filter and to the atmosphere. It is branched into a bypass passage. Alternatively, the first switching valve is provided with each of the branch passages downstream of the fiber filter, and the branch passage branches into an exhaust passage provided with the honeycomb filter and the bypass passage open to the atmosphere. However, a structure in which the branch passages downstream of the fiber filter are gathered in a collecting pipe requires a smaller number of parts.

The controller controls the heater to energize the heater in a state where the fiber filter has collected the particulate matter in a predetermined amount or more, and heats and burns the collected particulate matter to regenerate the fiber filter. I do. Further, the controller switches the first switching valve to flow the exhaust gas to the bypass passage when the pressure of the exhaust gas passing through the fiber filter becomes equal to or higher than a predetermined value. While the resistance rises and reaches a set value, the honeycomb filter is energized, and the particulate matter collected by the honeycomb filter is heated and incinerated to regenerate the honeycomb filter.

The diesel particulate filter device includes a first pressure sensor for detecting the pressure of the exhaust gas flowing through the exhaust passage upstream of the fiber filter, and the exhaust gas flowing through the collecting pipe downstream of the fiber filter. A second pressure sensor for detecting gas pressure is provided. Further, the controller may determine whether the particulate matter has been collected in a predetermined amount or more and the state in which the pressure of the exhaust gas passing through the fiber filter is equal to or less than a predetermined value, between the first pressure sensor and the second pressure sensor. Determined according to the detected value.

The fiber filter is formed of a nonwoven fabric in which laminated fiber materials and / or ceramic long fibers are laminated. Further, the fiber filter is folded in a fold shape and formed in a cylindrical shape as a whole, and the exhaust gas is sent from the outer peripheral side to the inner peripheral side of the fiber filter.

The present invention also provides a pair of branch passages for branching an exhaust passage through which exhaust gas discharged from the engine flows.
A fiber filter provided in each of the branch passages for trapping particulate matter in exhaust gas; and a heater provided in each of the fiber filters for heating and burning the particulate matter collected in the fiber filter. A switching valve that is switched to allow the exhaust gas to flow into one of the branch passages, a collecting pipe that collects the branch passage downstream of the fiber filter, and a pair of second branch passages that branch a downstream portion of the collecting pipe A dense honeycomb filter provided in the one second branch passage for collecting the particulate matter and heating and burning the collected particulate matter by energization; the second branch passage or open to the atmosphere; Another switching valve that is switched to flow the exhaust gas into the bypass passage of the second branch passage, upstream of the fiber filter First and second pressure sensors for respectively detecting the pressure of the exhaust gas flowing through the exhaust passage and the collecting pipe downstream of the fiber filter, and the heaters in response to detection values of the pressure sensors; And a diesel particulate filter device comprising a controller for controlling the operation of each of the switching valves.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a diesel particulate filter device (hereinafter, referred to as a DPF device) according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view showing an embodiment of a DPF device according to the present invention,
FIG. 2 is a graph showing the collection rate and exhaust resistance with respect to the collection elapsed time of the DPF device of FIG. 1, and FIG. 3 is a graph showing the collection rate and exhaust resistance with respect to the collection elapsed time of the honeycomb filter.

In this DPF device, casings 5 and 6 are disposed in an exhaust passage 10 composed of an exhaust pipe through which exhaust gas discharged from an engine such as a diesel engine flows. Support member 36,
37 attached. Fiber filters 1 and 2
Means carbon, smoke, HC, S contained in exhaust gas
Is intended to collecting particulates substances consisting of O _X, etc., in the wake of the fiber filters 1, the honeycomb filter 20 is arranged. In the exhaust passage 10 of the exhaust pipe,
A pair of branch passages 1 branched at the inlet side exhaust passage 10
1 and 12 are connected. In this DPF device, fiber filters 1 and 2 for collecting particulate matter contained in exhaust gas are arranged in parallel in branch passages 11 and 12 (first branch passages), respectively, and at the rear of the fiber filters 1 and 2. A honeycomb filter 20 is provided in the flow.

In this embodiment, the honeycomb filter 20
A switching valve 33 (first switching valve) is provided in a collecting pipe 17 in which branch passages 13 and 14 downstream of the fiber filters 1 and 2 are gathered.
0 is provided to an exhaust passage 18 and a bypass passage 19 which is open to the atmosphere. Of course, this DPF device is provided with a switching valve 33 in each of the branch passages 18 downstream of the fiber filters 1 and 2 without assembling the branch passages 13 and 14, and a honeycomb filter in the branch passage 18. 20 can be configured, but the structure in which the branch passages 13 and 14 downstream of the fiber filters 1 and 2 are gathered in the collecting pipe 17 requires fewer parts, and is cost-effective. It is advantageous.

The fiber filters 1 and 2 are filter bodies 3 and 4 composed of sheet-like and mat-like laminated fiber members made of laminated fiber materials such as ceramic fibers and / or non-woven fabrics laminated with long ceramic fibers. It is composed of Further, the fiber filters 1 and 2 are, for example, folded in a fold shape and formed in a cylindrical shape as a whole, and as shown by arrows, the exhaust gas flows from the exhaust gas passages 7 and 8 on the outer peripheral side of the fiber filters 1 and 2. It is configured to be sent to the exhaust gas passages 27 and 28 on the inner peripheral side. In addition, upstream wire meshes 38 and 39 and downstream wire meshes 40 and 41 are attached to the fiber filters 1 and 2 in order to prevent the fiber material from scattering in close contact with their surfaces. The fiber filters 1 and 2 formed in the cylindrical body have an upstream end portion with a shielding plate 29,
The downstream end is sealed by shielding plates 31 and 32 which open the outlet-side exhaust gas passages 27 and 28 at the center. Therefore, the exhaust gas that has passed through the exhaust passage 10 flows from the branch passages 11 and 12 into the inlet-side exhaust gas passages 7 and 8 through the through holes of the support members 36 and 37, and then flows into the inlet-side exhaust gas passages 7 and 8. From fiber filters 1 and 2
When passing through, the particulate matter is collected, discharged to the outlet-side exhaust gas passages 27 and 28, and flows to the outlet-side branch passages 13 and 14.

In this DPF device, a switching valve 9 (second switching valve) that is switched at a branch portion of the exhaust passage 10 to the branch passages 11 and 12 to flow exhaust gas to one of the branch passages 11 and 12. Is provided. The DPF device includes a pressure sensor 26 (first sensor) that detects the pressure Px of the exhaust gas flowing through the exhaust passage 10 upstream of the fiber filters 1 and 2.
A pressure sensor (pressure sensor) and a pressure sensor 15 (second pressure sensor) for detecting the pressure Px of the exhaust gas flowing through the collecting pipe 17 downstream of the fiber filters 1 and 2 are provided. The detection signals detected by the pressure sensors 15 and 26 are
Is input to The pressure of the exhaust gas from the pressure sensors 15 and 26 fluctuates depending on the engine rotation and the engine load. For example, the pressure Px of the exhaust gas is calculated from a pressure difference or the like based on the detection values from the upstream and downstream pressure sensors 15 and 26 of the exhaust gas flow to detect the deposition state of the particulate matter. I have.

In this DPF apparatus, in order to heat and incinerate the particulate matter collected in a predetermined amount or more, the wire mesh 38 located upstream of the fiber filters 1 and 2 in the fiber filters 1 and 2 in this embodiment. , 39 is heater 3
8, 39. In addition, the honeycomb filter 2
Numeral 0 is made of a conductive material or is provided with a heater 43 such as a wire mesh or coil embedded therein for heating and burning the collected particulate matter. Electric power is supplied to the heaters 38 and 39 from the power supply 35 such as a battery through the electrode terminals 23 and 24 according to a command from the controller 25. In addition, the honeycomb filter 20 or the heater 43 provided therein is configured to be energized from a power source 35 such as a battery through an electrode terminal 42 in accordance with a command from the controller 25. Although the pressure is detected in order to detect the trapping amount of the honeycomb filter 20, the trapping time may be detected by a timer and the switching of the switching valve 33 may be controlled.

The controller 25 includes an actuator 16
Is operated to switch the switching valve 9. In the switching operation, first, the particulate matter is collected by one of the fiber filters 1 or 2. At that time, the collection of the particulate matter of the fiber filter 1 or 2 is performed. The pressure Px of the exhaust gas changes according to the amount, that is, the deposition amount. Therefore, when the pressure Px of the exhaust gas is equal to or higher than the predetermined value Pa (Px ≧ Pa), the controller 25 determines that the fiber filter 1 or 2 is in a state where it cannot collect any more particulate matter, and determines that the 16 is operated to switch the switching valve 9 to control the flow of the exhaust gas to flow to the fiber filter 1 or 2 on the other side.

The downstream side of the fiber filters 1 and 2 communicates with a collecting pipe 17 which collects the downstream branch passages 13 and 14 with each other. The wake of the collecting pipe 17 is divided into the branch passages 18 and 1
9 (second branch passage). A honeycomb filter 20 is disposed in one branch passage 18, and a bypass passage 19 is formed in the other branch passage 19 so as to discharge exhaust gas to the outside. Bypass passage 19
Although this embodiment is open to the atmosphere in this embodiment, it can also be connected to the branch passage 18 downstream of the honeycomb filter 20 to connect equipment such as a muffler.

Thus, the DPF device has a honeycomb filter 2
A switching valve 33 which is switched by an actuator 34 to flow exhaust gas to the honeycomb filter 20 or the bypass passage 19 to the collecting pipe 17 of the exhaust passage on the upstream side of
(First switching valve) is provided. Controller 25
Means that the pressure Px of the exhaust gas passing through the switching valve 33 through the fiber filters 1 and 2 is equal to or lower than a predetermined value (Px <Pb
<Pa), exhaust gas is passed through the honeycomb filter 20,
When the pressure Pb is equal to or higher than a predetermined value (Pa> Px ≧ Pb), switching control is performed so that the exhaust gas flows into the bypass passage 19.

The controller 25 comprises fiber filters 1 and 2
Determines the state in which the particulate matter is collected in a predetermined amount or more, and the state in which the pressure of the exhaust gas passing through the fiber filters 1 and 2 is equal to or lower than a predetermined value according to the detection values of the pressure sensor 26 and the pressure sensor 15. is there. That is, the controller 25
Is the pressure (Px ≧ Pa) in a state where one of the fiber filters 1 or 2 has collected the particulate matter in a predetermined amount or more.
So that the exhaust gas flows to the other fiber filter 2 or 1
The switching of the switching valve 9 is controlled by operating the actuator 16. Further, the controller 25 energizes the heater 38 or 39 at a pressure (Px ≧ Pb) in a state where the fiber filter 1 or 2 has collected a predetermined amount or more of the particulate matter, and heats and incinerates the collected particulate matter. The control for regenerating the fiber filter 1 or 2 is performed.

Further, after the pressure of the exhaust gas passing through the fiber filters 1 and 2 becomes equal to or higher than a predetermined value and the switching valve 33 is switched so that the exhaust gas flows to the bypass passage 19, the controller 25 controls the honeycomb filter 20. (Or the heater 43), the particulate matter trapped in the honeycomb filter 20 is heated and incinerated to regenerate the honeycomb filter 20.

Since the DPF device is configured as described above, it can operate as follows. As shown by the dotted line in FIG. 2, the fiber filters 1 and 2 have a trapping rate of the particulate matter of about 60% at the start of the collection of the particulate matter. As they accumulate, for example, 20
After one minute, the trapping rate increases to 90%, and the exhaust resistance at that time is extremely low at the start of trapping the particulate matter, and increases as the particulate matter accumulates on the fiber filters 1 and 2, and after 60 minutes have elapsed. But 150
mmHg or less. On the other hand, as shown in FIG. 3, the honeycomb filter 20 has a particulate matter collection rate of 90% at the start of particulate matter collection.
As described above, the particulate matter is the fiber filter 1,
For example, after 20 minutes, the exhaust resistance reaches 60 mmHg after 30 minutes, and after 30 minutes, trapping of the particulate matter by the honeycomb filter 20 causes the exhaust resistance to become too high, making it difficult to flow exhaust gas. Become.

This DPF device switches the switching valve 9 and the switching valve 33 at the time of starting collection of the particulate matter contained in the exhaust gas.
And the honeycomb filter 20 are made to flow, and the particulate matter is collected by the fiber filter 1 and the honeycomb filter 20. As a result, the DPF device can reduce the particulate matter collection rate from the start of collection to 9%.
0% or more, and when the exhaust resistance of the honeycomb filter 20 is increased, for example, after 20 minutes, the switching valve 33 is switched to allow the exhaust gas to pass through the bypass passage 1.
9 to switch to a state in which the particulate matter is collected only by the fiber filter 1. At this time, the honeycomb filter 20 (or the heater 43) is energized, and the particulate matter collected in the honeycomb filter 20 is heated and incinerated to regenerate the honeycomb filter 20. Therefore, when a predetermined amount of particulate matter is deposited on the fiber filter 1, the particulate matter is collected only by the fiber filter 1, so that the exhaust resistance increases slowly.
Long-term collection can be continued.

Next, this DPF device switches the switching valve 9 so that the exhaust gas flows to the other fiber filter 2 when the trapped amount of the particulate matter in the fiber filter 1 becomes a predetermined amount or more. The switching valve 33 is switched so that the exhaust gas flows to the honeycomb filter 20, and the fiber fill 2 and the honeycomb filter 20 are switched to a state of collecting particulate matter. At this time, the heater 38 provided in the fiber filter 1 is energized,
Heating and burning the particulate matter collected in
The fiber filter 1 is regenerated. As described above, this DPF device operates by switching between the process of collecting and regenerating the particulate matter from the exhaust gas.
The characteristics possessed by the fiber filter 1 or 2 and the honeycomb filter 20 are effectively exhibited, and the particulate matter from the exhaust gas is properly and properly removed, and there is no need to perform a short-time switching operation, and the collection efficiency of the particulate matter is improved. Can be raised.

[0030]

As described above, the diesel particulate filter device according to the present invention is configured as described above, so that the low collection rate at the time of starting the collection by the fiber filter can be compensated for by the honeycomb filter. A high trapping rate can be secured from the start of particulate matter collection with the total trapping rate with the filter, and after several minutes, the state is switched to the state of collecting particulate matter only with the fiber filter, so the rise in exhaust resistance is moderate. And the ideal DP
An F apparatus can be configured.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one embodiment of a diesel particulate filter device according to the present invention.

FIG. 2 is a graph showing a collection rate and an exhaust resistance with respect to a collection elapsed time for the diesel particulate filter device of FIG.

FIG. 3 is a graph showing a collection rate and an exhaust resistance with respect to a collection elapsed time of a honeycomb filter.

[Explanation of symbols]

 1, 2 Fiber filter 3, 4 Filter body 7, 8 Inlet-side exhaust gas passage 9, 33 Switching valve 10, 18 Exhaust passage 11, 12, 13, 14 Branch passage 15, 26 Pressure sensor 16, 34 Actuator 17 Collecting pipe 19 Bypass passage 20 Honeycomb filter 25 Controller 27, 28 Outlet side exhaust gas passage 38, 39, 43 Heater

Claims (14)

[Claims] 1. A fiber filter disposed in an exhaust passage through which exhaust gas discharged from an engine flows to collect particulate matter in exhaust gas, and the fiber filter disposed in the exhaust passage downstream of the fiber filter. A dense honeycomb filter that collects the curable substance, an upstream portion of the honeycomb filter that is switched to allow the exhaust gas to flow through one of the exhaust passage in which the honeycomb filter is installed and a bypass passage that bypasses the honeycomb filter. When the pressure of the exhaust gas passing through the first switching valve installed in the exhaust passage and the fiber filter is equal to or lower than a predetermined value, the exhaust gas flows through the honeycomb filter, and when the pressure of the exhaust gas is equal to or higher than the predetermined value, the exhaust gas is discharged. A diesel engine comprising a controller for switching and controlling the first switching valve so as to flow through the bypass passage. Ruparticulate filter device. 2. The fiber filter is provided in each of a pair of branch passages branching from the exhaust passage, and the exhaust passage includes a second switching valve that is switched to flow the exhaust gas to one of the branch passages. 2. The diesel particulate filter device according to claim 1, wherein the filter is provided. 3. The controller controls switching of the second switching valve so that the exhaust gas flows through the other fiber filter while one of the fiber filters collects the particulate matter in a predetermined amount or more. The diesel particulate filter device according to claim 2, comprising: 4. The diesel particulate filter device according to claim 1, wherein the fiber filter is provided with a heater such as a wire mesh for heating and burning the collected particulate matter. 5. The diesel particulate filter according to claim 1, wherein the honeycomb filter is made of a conductive material or provided with a heater to heat and incinerate the collected particulate matter. apparatus. 6. The first switching valve is provided in a collecting pipe in which the branch passages downstream of the fiber filter are gathered, and the downstream of the collecting pipe is connected to the exhaust passage provided with the honeycomb filter and the atmosphere. 2. The diesel particulate filter device according to claim 1, wherein the filter is branched into the open bypass passage. 7. The first switching valve is provided in each of the branch passages downstream of the fiber filter, and the branch passage branches into the exhaust passage provided with the honeycomb filter and the bypass passage open to the atmosphere. 2. The diesel particulate filter device according to claim 1, wherein 8. The controller regenerates the fiber filter by heating and burning the collected particulate matter by energizing the heater while the fiber filter has collected the particulate matter in a predetermined amount or more. 2. The diesel particulate filter device according to claim 1, wherein the control is performed. 9. The controller according to claim 1, wherein the controller controls the first switching valve to flow the exhaust gas to the bypass passage when a pressure of the exhaust gas passing through the fiber filter becomes equal to or higher than a predetermined value. Since the exhaust gas passage resistance increases and reaches a set value, the honeycomb filter is energized, and the particulate matter collected by the honeycomb filter is heated and incinerated to regenerate the honeycomb filter. The diesel particulate filter device according to claim 1, comprising: 10. A first pressure sensor for detecting a pressure of the exhaust gas flowing in the exhaust passage upstream of the fiber filter, and detecting a pressure of the exhaust gas flowing in the collecting pipe downstream of the fiber filter. 2. The diesel particulate filter device according to claim 1, further comprising a second pressure sensor. 11. The first pressure sensor and the second pressure sensor determine whether the particulate matter is collected in a predetermined amount or more and the pressure of the exhaust gas passing through the fiber filter is equal to or less than a predetermined value. 11. The diesel particulate filter device according to claim 10, wherein the determination is made in accordance with a value detected by a sensor. 12. The diesel particulate filter device according to claim 1, wherein the fiber filter is made of a nonwoven fabric in which laminated fiber materials and / or ceramic long fibers are laminated. 13. The fiber filter according to claim 1, wherein the fiber filter is folded in a fold shape and formed in a cylindrical shape as a whole, and the exhaust gas is sent from an outer peripheral side to an inner peripheral side of the fiber filter. Diesel particulate filter device. 14. A pair of branch passages for branching an exhaust passage through which exhaust gas discharged from an engine flows, a fiber filter provided in each of the branch passages for collecting particulate matter in exhaust gas, and a fiber filter. A heater provided in each of the fiber filters to heat and incinerate the collected particulate matter; a switching valve switched to flow the exhaust gas through one of the branch passages; A collecting pipe for collecting the branch passages, a pair of second branch passages for branching a downstream portion of the collecting pipe, and the particulate matter provided and collected in the one second branch passage; A dense honeycomb filter capable of heating and incinerating a curated substance by energization, and a cover of the second branch passage or the second branch passage opened to the atmosphere. Another switching valve that is switched to flow the exhaust gas through the bypass passage, and a first valve that detects the pressure of the exhaust gas flowing through the exhaust passage upstream of the fiber filter and the collecting pipe downstream of the fiber filter. And a second pressure sensor, and a controller that controls the operation of each of the heaters and each of the switching valves in response to a detection value of each of the pressure sensors.