JP3082635B2 - Particulate trap device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particulate trap apparatus for removing particulates from exhaust gas of a diesel engine, and more particularly, to a particulate trap which can timely incinerate and regenerate particulates collected by the particulate trap. It concerns the device.

[0002]

2. Description of the Related Art Diesel engine exhaust gas contains
A particulate trap containing particulate filters is installed on the exhaust gas flow path of the diesel engine to collect particulates without releasing them to the atmosphere. It is effective to be. This type of particulate trap increases the amount of trapped particulate as the traveling time of the vehicle increases.
When such a state is reached, the particulate trap increases the flow resistance of the exhaust gas flow path of the vehicle and suppresses the output. Therefore, in a normal particulate trap, the collected particulates are heated to a predetermined temperature by an electric heater disposed on the exhaust gas inflow side inside the particulate trap, and outside air is taken in by an air pump or the like while being pumped as secondary air. They burn and regenerate the particulate trap.

[0003] An example of such an apparatus is disclosed in Japanese Patent Laid-Open No. 5-21.
No. 4924. The technology disclosed in the publication is
A pair of branch paths are provided in the exhaust path, a pair of filters are provided in parallel in the same section, and a regeneration exhaust gas exhaust pipe is provided between the pair of branch paths via an on-off valve. When the filter is switched, the on-off valve is opened, and high pressure is released from one branch to the other branch, thereby alleviating the back pressure fluctuation of the filter.

[0004]

By the way, a conventional particulate trap apparatus, for example, Japanese Patent Laid-Open No. 5-21 / 1990
In the apparatus and the like disclosed in 4924, it is necessary to drive an air pump to incinerate the particulates and supply the secondary air into the particulate traps when regenerating the particulate traps, which requires an air pump which tends to increase the cost. I do. In addition, it is necessary to control the exhaust gas supplied from the communication passage so that the combustion temperature of the particulates can be maintained within an appropriate range, and to maintain the durability of the particulate trap. This also tends to cause an increase in cost, and improvement is desired. An object of the present invention is to provide a particulate trap device that can reduce the cost.

[0005]

According to the first aspect of the present invention,
An exhaust pipe, first and second branch pipes connected to the exhaust pipe,
First and second particulate traps for collecting particulates in exhaust gas respectively disposed in the first and second branch pipes, and opening and closing the first and second branch pipes on the upstream side of the particulate traps switching valve and, the first between the switching valve and the particulate traps, and the communication path for communicating the second branch pipe through the orifice, communicating state and a non-a same communication path is provided in the communication passage to Switch to communication state
An opening / closing valve, a regeneration timing detecting means for detecting a regeneration timing of the particulate trap, a particulate trap regeneration means for regenerating the particulate trap by burning the particulates collected in the particulate trap, The switching valve is operated so as to close the branch pipe on the side of the particulate trap that needs to be regenerated by the output of the regenerating timing detecting means, the particulate trap regenerating means is operated, and the particulate trap is operated. When the temperature exceeds the combustion temperature, open the on- off valve and communicate with the communication passage
And control means for setting the state .

According to a second aspect of the present invention, in the particulate trap device according to the first aspect, a bypass passage provided in the communication passage and having a passage resistance larger than that of the communication passage, and a bypass passage according to an operation state during regeneration. And a switching means for closing one of the communication path and the bypass path.

[0007] The invention according to claim 3 is claim 1 or claim 1.
Item 2. The particulate trap device according to Item 2 ,
The control means has a regeneration timing detecting means for detecting an elapsed time from the start of regeneration of the particulate trap, and when the detected time exceeds a preset value, the temperature of the particulate trap becomes equal to or higher than the combustion temperature. The on-off valve is opened. The invention of claim 4, wherein, in the particulate trap system according to claim 2, wherein said switching means when the engine speed during reproduction is larger than a predetermined value, characterized by closing said communication passage. According to a fifth aspect of the present invention, in the particulate trap device according to the fourth aspect , the control means includes a regeneration timing detecting means for detecting an elapsed time from the start of the regeneration of the particulate trap, and When the temperature exceeds a preset value, the on-off valve is opened assuming that the temperature has become equal to or higher than the combustion temperature of the particulates.

According to a sixth aspect of the present invention, in the particulate trap device according to the first aspect, an intermediate portion of the communication passage has a small-diameter first flow adjustment passage and a large-diameter second flow adjustment passage arranged in parallel. The on-off valve is formed of a first on-off valve for opening and closing the first flow rate adjustment path and a second on-off valve for opening and closing the second flow rate adjustment path. If the operating state at the time of regeneration is equal to or lower than the first rotation speed after the combustion temperature or higher, both the first and second on-off valves are opened, and if the operating state is equal to or higher than the first rotation speed and equal to or lower than the second rotation speed. Only the second on-off valve is opened, and if the rotation is equal to or more than the second rotation, only the first on-off valve is opened.

According to a seventh aspect of the present invention, in the particulate trap device according to the sixth aspect , the control means is in a first operating range in which the operating state during regeneration is equal to or lower than the first rotational speed and equal to or lower than the first load. And the first and second on-off valves are both opened, and only the second on-off valve is opened if the operating state is outside the first operating range and in the second operating range below the second rotational speed and below the second load. When the operating state is in a third operating range other than the first and second operating ranges and below the maximum rotational speed and below the maximum load, only the first on-off valve is opened.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numerals 10A and 10B denote first and second particulate traps (hereinafter, referred to as a first trap 10A and a second trap 10B), respectively. The first trap 10A and the second trap 10B are provided in an exhaust system of the diesel engine E. In particular, the exhaust system branches off a downstream side of a main exhaust pipe 8 connected to an exhaust manifold 7 and includes therein. A first trap 10A is provided in the first branch pipe 8A, and a second trap 10B is provided in the second branch pipe 8B. Here, the first trap 10A,
The second trap 10B has the same configuration, and here, the first trap 10A will be mainly described. The configuration of the second trap 10B is illustrated by adding a B to the end of the reference numeral used for the first trap 10A.

As shown in FIG. 2, the first trap 10A is housed through a wire mesh 12A inside a bulging portion 2Aa at the center of a casing 2A, and is made of a ceramic material for collecting particulates in exhaust gas. Particulate filter 1A (hereinafter referred to as filter 1A)
The filter 1A is disposed on the exhaust gas inflow side of the filter 1A.
It mainly comprises an electric heater 6A for heating A and burning the trapped particulates, and a heat reflecting plate 11A provided with a large number of ventilation holes disposed further in front of the electric heater 6A. The casing 2A has a bulging portion 2Aa formed at the center thereof, and a front and rear cone portion 3A,
4A is formed. A first branch pipe 8A is connected to the front cone section 3A, and an exhaust pipe to a muffler (not shown) is connected to the rear cone section 4 respectively.

As shown in FIG. 2, the filter 1A is made of a ceramic having a honeycomb structure in which a number of narrow paths 28A are stacked in the same direction, and is made of particulates from exhaust gas passing through the side walls of the narrow paths 28A. Is configured to be filtered. As shown in FIG. 1, the electric heaters 6A and 6B of the traps 10A and 10B are connected to the battery 26 via the switches SA and SB, and are energized during filter regeneration to generate heat. The switching input terminals of the switches SA and SB are connected to an engine control unit 14 (hereinafter, referred to as ECU 14) as control means described later. The electric heaters 6A and 6B are distributed almost uniformly in the cross-sectional direction of the exhaust gas flow path, and heat the particulates collected in the filters 1A and 1B by heat energy generated by heat generation.
Burn. The heat reflecting plates 11A and 11B reflect the heat radiated to the opposite sides of the filters 1A and 1B, or absorb the heat once and return it to flowing exhaust gas to promote the heating of the particulates. Reference numeral 27 indicates an alternator.

First trap 10A, second trap 10B
The switching valves 18 and 19 connected to the ECU 14 and operated by the actuators 18a and 19a are arranged upstream of the exhaust gas inflow side. In response to a signal from the ECU 14, the switching valves 18 and 19 close the first branch pipe 8A when the trap 10A is being regenerated, and close the second branch pipe 8A when the trap 10B is being regenerated.
Close B. The first branch pipe 8A and the second branch pipe 8B are
Upstream of the first trap 10A and the second trap 10B on the exhaust gas inflow side, the first trap 10A and the second trap 10B communicate with each other through the communication path 5.
An opening / closing valve 9 for opening / closing the communication passage 5 by an actuator 9a connected to the ECU 14 is disposed at substantially the center of the opening / closing valve. The on-off valve 9 is normally closed, is operated based on a signal from the ECU 14 during regeneration of the filter 1A or 1B, and supplies exhaust gas to the first trap 10A or the second trap 10B during regeneration. This diesel engine E is operated at a high rate under excess oxygen, and oxygen contained in exhaust gas can burn particulates.

An orifice 20 for reducing the flow rate of exhaust gas supplied to the first trap 10A or the second trap 10B during regeneration is provided in the communication passage 5 between the on-off valve 9 and the first branch pipe 8A.
Is provided. The orifice 20 prevents the filter from being melted down due to an excessive rise in temperature of the filter 1A or the filter 2A during the regeneration, and regulates the flow rate of the exhaust gas in order to quickly terminate the regeneration. FIG. 6 shows the engine speed Ne based on the experimental data performed by the inventor.
- shows an example of a change characteristic of the reproduction time of the filter the maximum temperature G _T. Here, a direct injection small diesel engine was used, and the exhaust system of the engine was configured in the same manner as in FIG. Here, the inner diameter of the orifice provided in the communication passage is changed to φ4 (broken line) and φ8 (solid line), and the trapped amount of particulates is changed to 70 g and 90 g. change characteristic of the reproduction time of the filter the maximum temperature G _T and the number Ne are different. In particular, when the inner diameter of the orifice is φ8 (solid line) and the amount of trapped particulates is 90 g, the engine speed Ne is 1250 rpm.
Playback Filter the maximum temperature at the point in excess of m G _T it is apparent that above the melting temperature of the filter (1400 ° C.).

The main exhaust pipe 8 is provided with a pressure sensor 21 as a regeneration timing detecting means for detecting a regeneration timing of the first trap 10A and the second trap 10B. The pressure information from the pressure sensor 21 is input to the ECU 14. E
The main part of the CU 14 is constituted by a microcomputer,
The control unit, the switching unit, and the regeneration timing detecting unit have a function of controlling energization of the electric heaters 6A, 6B and controlling the switching valves 18, 19 and the opening / closing valve 9 based on various information.
That is, the energization time of the electric heaters 6A and 6B is measured. And opening the on-off valve 9 as it becomes less than the combustion temperature of the particulate when detected time (the value of the TIM1) exceeds a preset value T _H. Further, the engine speed Ne during regeneration is set to a predetermined value (for example, 1200 rpm).
If it is larger than m), the communication path 5 is closed.

The operation will be described below with reference to the control flowchart of the particulate trap device shown in FIG.
In this example, use is started from the first trap 10A. When an engine key (not shown) is turned on, the engine E, the ECU 14, and various sensors operate, and the exhaust gas from the engine E reaches the filter 1A from the main exhaust pipe 8 via the first branch pipe 8A, where particulates are collected. And then released into the atmosphere. When the ECU 14 operates, the pressure information from the pressure sensor 21 is fetched in steps s1 and s2, and the process proceeds to step s3 unless the regeneration flag FLG1 is on, and proceeds to step s8 when the regeneration flag FLG1 is on. In step s3, it is determined whether or not the pressure signal from the pressure sensor 21 has reached a predetermined value, that is, whether or not the amount of trapped particulates has reached a pressure of 90 g, that is, whether or not the filter 1A has entered the regeneration time.

If No in step s3, step s3
Then, the program proceeds to step S4, where the regeneration timer TIM1 for counting the heater driving time and the incineration time counter CUT1 are reset, the regeneration flag FLG1 is turned off, and the process returns to the main routine. In step s5, the regeneration flag FLG1 is turned on assuming that regeneration has started, and in step s6, the actuators 18a and 19a are operated to operate the switching valve 18 in the closed state and the switching valve 19 in the open state, respectively. To step s7, and switch S
A is activated to energize the electric heater 6A. Step s8
Now, the regeneration timer TI that counts the heater drive time
It is determined whether or not the value of M1 has exceeded a set time T _H that can be considered to have reached the temperature at which the particulates can be burned, wait for the value to exceed, and proceed to step s9.

[0018] Here, 1200 rpm the exhaust temperature G _T is likely to exceed the melting temperature of the filter (1400 ° C.)
Is determined to be higher than the engine speed Ne. When the engine speed Ne falls below 1200 rpm, the process proceeds to step s11, where the on-off valve 9 is turned on to open the communication passage 5,
The exhaust gas is guided to the filter 1A via the second branch pipe 8B and the communication path 5. The exhaust gas burns the particulates deposited on the filter 1A by the oxygen in the exhaust gas. At this time, the orifice 20 of the communication passage 5 restricts the flow rate of the exhaust gas passing therethrough, thereby restricting the temperature of the filter from excessively rising. Thereafter, in step s12, the value of the incineration time counter CUT1 is updated by adding n, and the process proceeds to step s13. Here, the addition value n is set in advance so as to increase stepwise in an appropriate engine speed range.

On the other hand, when the engine speed Ne is 1200 rpm
If m is exceeded, the process proceeds to step s10, the on-off valve 9 is turned off to close the communication path 5, the introduction of exhaust gas to the filter 1A is stopped, and the process proceeds to step s13. Accordingly, it is possible to prevent a large amount of exhaust gas from being supplied to the filter 1A at the time of high rotation and the filter 1A from being melted. Step s13
When reached, the value of the incineration time counter CUT1 it is determined whether or not above the burning completion time T _C corresponding value Tα is a set value, waits for the above, reached a step s14 at above, it operates the actuator 9a To close the on-off valve 9,
The reproduction flag FLG1 is turned off to complete the reproduction process.

As described above, the particulate trap device shown in FIG. 1 can burn the particulates trapped in the particulate trap with oxygen contained in the exhaust gas.
The cost of the device can be reduced. Moreover, orifices can supply an appropriate amount of the exhaust gas amount to particulate trap during playback, in a timely manner to TIM1 elapsed time from the start of reproduction of particulate trap exceeds a preset value T _H, the particulate combustion temperature As described above, exhaust gas for incineration can be supplied. Next, a second embodiment of the present invention will be described.

The configuration of the particulate trap device according to the second embodiment shown in FIG. 4 is different from that of the particulate trap device shown in FIG. Many components,
Here, the same members are denoted by the same reference numerals, and the description thereof will not be repeated. Communication passage 3 of the particulate trap device in FIG.
0 is a bypass passage 3 having a larger flow path resistance than the same communication passage.
1, an on-off valve A32 provided on the communication passage 30 not opposed to the bypass passage 31, a switching valve B33 as switching means for closing one of the communication passage and the bypass passage, the communication passage 30 and the bypass passage 31 Each orifice 34,3
5 is provided. The on-off valve A32 and the switching valve B33 are both connected to the ECU 36.

The on-off valve A32 opens the communication passage 30 between the first branch pipe 8A and the second branch pipe 8B when turned on, and closes when turned off. The orifice 34 provided in the portion of the communication passage 30 facing the bypass passage 31 has an inner diameter of φ8, and the orifice 35 provided in the bypass passage 31 has an inner diameter of φ4. The switching valve B33 in which the valve element is disposed at the confluence of the communication passage 30 and the bypass passage 31 has the first position P1 shown in FIGS. 4 and 5A and 5B when turned off.
5C, the bypass passage 31 is closed, the communication passage 30 is opened, and when it is turned on, it is held at the second position P2 shown in FIG. 5C, the bypass passage 31 is opened, and the communication passage 30 is closed.

The ECU 36 has a microcomputer as a main part, and controls the energization of the electric heaters 6A and 6B, and controls the opening / closing valve A32 and the switching valve B33 based on various information as control means, switching means and regeneration timing detecting means. It has a function to do. That is, the energization time of the electric heaters 6A and 6B is measured. Then, the detected time is a preset value T _H
Is exceeded, the on-off valve A32 is opened assuming that the temperature has become equal to or higher than the particulate combustion temperature. Further, one of the communication passage 30 and the bypass passage 31 having a larger flow path resistance than the communication passage is closed according to the operation state at the time of regeneration. In particular, when the engine speed Ne during regeneration is higher than a predetermined value (for example, 1200 rpm), the communication path 30
To close.

Next, the control operation of the ECU 36 according to the second embodiment will be described with reference to a regeneration control routine shown in FIG. Note that the reproduction control routine shown in FIG. 7 has many of the same steps as the reproduction control routine of FIG. 3, and the description of overlapping parts will be simplified here. When the ECU 36 operates, steps a1,
At a2, pressure information is fetched, and the process proceeds to step a3 unless the regeneration flag FLG1 is turned on. In step a3, the process waits until the amount of trapped particulates reaches a pressure of 60 g. During the waiting time, the process proceeds to step a4, where the regeneration timer T
The IM1 and the incineration time counter CUT2 are reset, and the regeneration flag FLG1 is turned off. Collected amount is 60g
When the pressure reaches, the process proceeds to steps a5 to a7, at which the regeneration flag FLG1 is turned on, and the switching valve 1
By operating the switch 8 in the closed state and the switching valve 19 in the open state, the collection filter is switched, and the electric heater 6A is energized.

When reaching step a8, the reproduction timer T
Value of IM1 is, wait for exceeds the set time T _H considered to have reached the above combustible temperature of the particulate, the process proceeds to above Step a9. In step a9, it is determined whether or not the engine speed Ne exceeds a predetermined value 1200 rpm.
2 is turned on and opened, and the switching valve B33 is turned off.
As shown in (b), the valve body of the switching valve B33 is moved to the first position P1.
To hold. Thereby, the communication path 30 is opened, and the exhaust gas is filtered through the second branch pipe 8B and the communication path 30 by the filter 1A.
To burn the particulates deposited on the filter 1A.

At this time, the orifice 34 of the communication passage 30 restricts the flow rate of the exhaust gas passing therethrough, thereby preventing the temperature of the filter from rising excessively.
The playback filter maximum temperature G _T characteristic shown by the solid line of 90g is obtained can be prevented from reaching the filter melting temperature (1400 ° C.). Thereafter, in step a12, a preset addition value n (= f ₂ (Ne)) is determined so as to increase stepwise with the engine speed range, and the addition value n is added to the value of the incineration time counter CUT2. , And the process proceeds to step a13.

On the other hand, when the engine speed Ne is 1200 rpm
If m is exceeded, the process proceeds to step a10, where the on-off valve A32 is turned on, the switching valve B33 is turned on, and a part of the on-off valve A32 and the bypass passage 31 are communicated as shown in FIG.
The exhaust gas is guided to the filter 1A through the second branch pipe 8B and the communication passage 30 and the bypass passage 31, and the particulates accumulated on the filter 1A are burned. At this time, although the engine speed Ne is in a high rotation range, the orifice 35 (inner diameter is φ
4) can restrict a large amount of exhaust gas during high rotation is supplied to the filter 1A, obtained a playback filter maximum temperature G _T characteristic shown in dashed excessive collection of 90g of Figure 6, the filter 1A is dissolved Loss can be prevented. Thereafter, the value of the incineration time counter CUT2 is updated by adding the added value n to the value of the incineration time counter CUT2 in the above-described step a12, and the process proceeds to step a13.

At step a13, the incineration time counter CU is used.
It is determined whether or not the value of T2 exceeds the incineration completion time Tβ, which is the set value.
4, the actuator 9a is operated to close the on-off valve 9, and the regeneration flag FLG1 is turned off to complete the regeneration process. As described above, the particulate trap device shown in FIG. 4 has the same operation and effect as the device shown in FIG. An orifice 34 having a small flow resistance (inner diameter φ8) is used in a low rotational speed range of Ne, and an orifice 35 (inner diameter φ is large) in a high rotational speed range.
Use 4). This promotes incineration in the low rotation speed range, restricts a large amount of exhaust gas from heating the filter 1A in the high rotation speed range, and prevents the filter 1A from being melted.

Next, a third embodiment of the present invention will be described. The configuration of the particulate trap device of the third embodiment shown in FIG. 8 is different from that of the particulate trap device of FIG. 1 in that the temperature detecting means and its control configuration described next are different, and the other components are the same. Many components are included here, and the same members are denoted by the same reference numerals, and redundant description thereof will be omitted.
The particulate trap device according to the third embodiment includes a temperature detecting means in the exhaust system. That is, as shown in FIG. 8, the first trap 10A and the second trap 10B are provided with temperature sensors 22A and 22B for detecting the temperatures of the respective traps. Temperature sensors 22A, 22B
Is connected to the ECU 40, and temperature information of each trap is gradually input to the ECU 40.

The ECU 40 fetches various information from the pressure sensor 21 and the temperature sensors 22A and 22B based on various kinds of information as control means, switching means and regeneration time detecting means, and based on these pieces of information, the electric heater 6A, 6B, and has a function of controlling the switching valves 18 and 19 and the on-off valve 9. Hereinafter, the operation will be described with reference to the control flowchart of the particulate trap device shown in FIG.
In this example, use is started from the first trap 10A.

When an engine key (not shown) is turned on, the engine E, the ECU 40 and various sensors operate, and the ECU
At step b1, various information is taken in from the pressure sensor 21 and the temperature sensors 22A and 22B. Step b
In step 2, it is determined whether the pressure has reached a predetermined value, that is, whether it is time to regenerate the filter 1A. In step b2, the process returns to the main routine until the reproduction condition is satisfied, and the process proceeds to step b3 with YES. Here, the actuators 18a and 19a are operated to switch the switching valve 18 to the closed state and the switching valve 19 to the open state to switch the trapping filter.
Is operated to energize the electric heater 6A.

At step b5, it is determined whether the temperature from the temperature sensor 22A is equal to or higher than the particulate combustion temperature. If the answer is no in step b5, the process returns. If the answer is yes, the process proceeds to step b6. The actuator 9a is operated to open the on-off valve 9, and the exhaust gas is filtered through the second branch pipe 8B and the communication passage 5. Lead to 1A. When the exhaust gas passes through the orifice 20 of the communication passage 5, its flow rate is reduced. Filter 1A by oxygen in exhaust gas
Burn the particulates deposited on the surface. Simultaneously with the opening of the on-off valve 9, the incineration time timer TIM2 operates to measure the opening time. Next, in step b7, it is waited that the open time of the on-off valve 9 exceeds the set time Tγ, that is, it is determined whether or not the combustion of the particulates is completed. When it exceeds, the process proceeds to step b8 to operate the actuator 9a. The on-off valve 9 is closed to complete the regeneration process.

As described above, the particulate trap apparatus shown in FIG. 8 has the same operation and effect as the apparatus shown in FIG. 1. In particular, the temperature information of the filters 1A and 1B is directly obtained by the temperature sensors 22A and 22B which are temperature detecting means. Can be detected, and incineration can be performed at an appropriate point in time to simplify control. Next, a fourth embodiment of the present invention will be described. The configuration of the particulate trap device of the fourth embodiment shown in FIG. 10 is different from that of the particulate trap device of FIG. 1 in that the communication passage 45 and the opening / closing control configuration of the passage described below are different. In this case, the same members are denoted by the same reference numerals, and the description thereof will not be repeated. As shown in FIGS. 10, 11, and 16, the communication path 45 of the particulate trap device includes a first flow control path 451 having a small diameter D1 and a second flow control path 452 having a large diameter D2. Are formed in parallel, and the first flow control passage 45
1 is opened and closed by the first on-off valve 41, and the second on-off valve 42 is opened and closed by the second on-off valve 42.

Here, the first flow control passage 451 and the second flow control passage 452 located at the intermediate portion of the communication passage 45 are both accommodated in the casing 48, and as shown in FIG. And the communication path 45 via the second connection port 45b. As shown in FIGS. 11, 13, and 16, the casing 48 includes a pair of first and second opening / closing valves 41 and 42 that are vertically arranged side by side. A main portion 483 in which the lower portions of the column portions 481 and 482 are integrated, a lower bulging portion 484 bulging below the center of the main portion 483, and a lateral bulging bulging rearward from the center of the main portion 483. The protrusion 485 is formed.

As shown in FIGS. 13 and 16, the first connection port 45a is formed at the center of the main portion 483, and the second connection port 4a is formed.
5b is formed in the lateral bulge 485. This second connection port 4
5b communicates with the center of the merging chamber 45d of the lower bulging portion 484 via the inclined path 45c. An opening 5 that is opened and closed by each valve is provided at each opposed portion of the merging chamber 45d with the first and second on-off valves 41 and 42.
11, 512 are formed. The opening 512 communicates with the first connection port 45a via the first flow rate adjustment path 451, and the opening 51
1 communicates with the first connection port 45a via the second flow rate adjustment path 452. Here, the first flow rate adjustment path 451 and the second flow rate adjustment path 452 are arranged on the same center line, thereby facilitating the machining of both holes. Reference numeral 52 denotes a blind cover of both flow control paths, and reference numeral 53 denotes first and second on-off valves 41 and 42.
And reference numeral 486 denotes a casing 4
8 shows a fixing bolt hole for fixing 8 to a base (not shown).

The first and second on-off valves 41 and 42 are provided with springs 54.
1, 542, the first and second on-off valves 4 are normally biased.
Each of the protruding ends of the air cylinders 1 and 42 is connected to the air cylinders 41a and 42a. As shown in FIG. 10, each air cylinder 41a,
42a is a first solenoid valve 43, a second solenoid valve 44 and an air pipe 4
7 and communicate with the high-pressure air tank 46. The first solenoid valve 43 and the second solenoid valve 44 are on-off valves that open when turned on, and are both connected to the ECU 50. As shown in FIG. 10, temperature sensors 22A and 22B for detecting the temperatures of the respective traps are arranged in the first trap 10A and the second trap 10B, respectively. The temperature sensors 22A and 22B gradually input temperature information of each trap to the ECU 50.

The ECU 50 fetches various information from the pressure sensor 21, the temperature sensors 22A and 22B, the engine speed sensor 55, and the load sensor 56 based on various information as control means, switching means, and regeneration timing detection means. Based on each information and the on-off valve map corresponding to the operation range in FIG. 18, the energization of the electric heaters 6A and 6B, the switching valve 18,
19 and a function of controlling the first solenoid valve 43 and the second solenoid valve 44. Here, the on-off valve map corresponding to the operating range indicates that the operating state at the time of regeneration is equal to or less than the first rotational speed Ne1 and the first load L1
In the following first operating range E _{(A + B)} , the first and second on-off valves 4
1 and 42 are both opened, and the operation state is the first operation area E.
_{(A + B)} and the second load L2 at the second rotational speed Ne2 or less.
If it is below the second operating region E _B is opened only the second on-off valve 42, the operating state is the first operating region E _{(A + B)} and and maximum speed Ne3 below except the second operating region E _B If it is the maximum load L3 following the third operating region E _a is set so as to open only the first on-off valve 41.

Hereinafter, the operation will be described with reference to the control flowchart of the particulate trap device shown in FIG. In this example, use is started from the first trap 10A. When an engine key (not shown) is turned on, the engine E, the ECU 50, and various sensors operate,
The ECU 50 fetches various information from the pressure sensor 21 and the temperature sensors 22A and 22B in step c1. In step c2, it is determined whether the pressure has reached a predetermined value, that is, whether it is time to regenerate the filter 1A. Step c2
Returns to the main routine until the reproduction condition is satisfied, and proceeds to step c3 with YES. Here, the actuators 18a and 19a are operated to switch the switching valve 18 to the closed state and the switching valve 19 to the open state to switch the trapping filter.
A is activated to energize the electric heater 6A.

When the process reaches step c5, it is determined whether the temperature from the temperature sensor 22A is equal to or higher than the particulate combustion temperature. If No in step c5, the process returns. If Yes, the process proceeds to step b6. In step c6, the engine speed Ne and the throttle opening signal as the load L, which are the current operation information, are detected and captured by the engine speed sensor 55 and the load sensor 56, respectively.
An operation range corresponding to the same value is calculated based on the on-off valve map. If it is the first operation range E _{(A + B)} , the process proceeds to step c7, where the first and second solenoid valves 43 and 44 are both turned on to open the first and second on-off valves 41 and 42, respectively. Second branch pipe 8B, first flow control path 451, and second flow control path 452
Exhaust gas to filter 1A through step c1
Go to 0. In this case, the exhaust gas passes through the communication passage 45 having a sufficiently large flow path cross-sectional area, reaches the filter 1A, and burns the particulates deposited on the filter 1A by the oxygen in the exhaust gas.

The second branch pipe 8B by opening only the second on-off valve 42 and turns on the second electromagnetic valve 44 proceeds to step c8 When it is the second operating region E _B, via the second flow regulating path 452 To guide the exhaust gas to the filter 1A, and the process proceeds to step c10. In this case, the flow rate of the exhaust gas is reduced by the second flow rate adjustment path 452 having a relatively large inner diameter D2 narrowed from the inner diameter of the communication path 45, and even in an operation range where the exhaust flow rate increases, the exhaust gas is deposited on the filter 1A. It is possible to regulate the supply of excess exhaust gas when burning the curate. The second branch pipe 8B and the first solenoid valve 43 is turned on to open only the first on-off valve 41 proceeds to step c9 If it is the third operating region E _A,
Exhaust gas is filtered through the first flow control passage 451 by the filter 1A.
To step c10. In this case, the exhaust gas has a relatively small inner diameter D which is sufficiently restricted from the inner diameter of the communication passage 45.
The first flow rate adjusting passage 451 narrows the flow rate sufficiently, so that the filter 1A can operate even in an operating range where the exhaust gas flow rate sharply increases.
It is possible to regulate the supply of excessive exhaust gas when burning the particulates accumulated in the fuel cell.

In step c10, if the on-flag ONFLG3 of the incineration time timer TIM3 described later is 1, the process proceeds to step c13; otherwise, the process proceeds to step c11. In step c11, immediately after the opening and closing of each of the on-off valves 41 and 42, the incineration time timer TIM3 is operated to start measuring the opening time. In step c12, the on-flag ONFLG3 is set to "1" and the process proceeds to step c13. Next, step c
13, the opening time of each of the on-off valves 41 and 42 is set to the set time T
Wait for δ ′ to be exceeded, that is, determine whether or not the particulate combustion is complete.
Then, the first and second solenoid valves 43 and 44 of the first and second on-off valves 41 and 42 are both turned off, and the regeneration process is completed.

As described above, the particulate trap device of FIG. 10 has the same operation and effect as the device of FIG.
In particular, in the first operation region E _{(A + B)} where the exhaust gas flow rate is small, a sufficiently large flow path cross-sectional area is ensured and the exhaust gas is filtered 1A.
Is supplied to the diaphragm and the flow rate through the second flow regulating passage 452 of relatively large inner diameter D2 throttled from the communication passage 45 inner diameter when is the second operating region E _B where the exhaust flow rate increases, the filter 1
Regulating the excessive supply of exhaust gas to the A, Part by the first flow rate adjustment path 451 of relatively small inner diameter D1 that is squeezed sufficiently from the communication passage 45 inner diameter If it is the third operating region E _A the exhaust flow rate increases rapidly The flow rate is sufficiently reduced to restrict the supply of excess exhaust gas to the filter 1A.

Therefore, the first and second flow control paths 451,
The cross-sectional area (orifice area) of 452 is selectively increased or decreased to adjust the throttling effect on the exhaust gas, and the filter 1A (1
B) The variation in the amount of exhaust gas supplied to B) is reduced. That is, when the exhaust gas has a low flow rate, it smoothly leads to the filter, and when the exhaust gas has an excessive amount, the flow into the filter is suppressed. As a result, as shown in FIG. Can hold. Thus, as shown in FIG. 20, even when the operating range of the engine is different, the filter 1A is always
In (1B), the regeneration process is performed under the optimal regeneration condition, so that the life of the filter can be prevented from being shortened, and the regeneration control is facilitated.

As described above, FIG. 1, FIG. 4, FIG.
0 can send the exhaust gas from the other of the first and second branch pipes 8A and 8B to the particulate trap 10A (or 10B) being regenerated on one of the branch pipes, Particulates trapped in the particulate trap can be incinerated with oxygen contained in the exhaust gas, the particulate trap can be reliably regenerated, and a secondary air pump is not particularly required, thereby suppressing an increase in the cost of the apparatus. Furthermore, the particulate trap device may be provided with an orifice 20 in the communication passage 5. In this case, the amount of exhaust gas sent to the particulate trap 10A (or 10B) during regeneration can be adjusted to an appropriate amount, and the particulate trap can be prevented from being damaged by excessive exhaust gas supply.

Further, the particulate trap device comprises:
The communication path 5 may include, in particular, a bypass path 31 having a larger flow path resistance than the communication path, and switching means 33 for closing one of the communication path 5 and the bypass path 31. In this case, the communication path 5 and the bypass path 31 can be selectively switched and used according to the operation state at the time of regeneration, and the fluctuation of the regeneration time can be regulated irrespective of the fluctuation of the operation state, thereby facilitating the control. In addition, the particulate trap device
Orifices 34 and 35 may be provided in at least one of the bypass passage 31 and the communication passage 5. In this case, it becomes easy to adjust the flow rate of the exhaust gas sent to the particulate trap 10A (or 10B) during the regeneration, and the variation in the regeneration time can be further reduced.

Further, the particulate trap device is
The ECU 36 particularly controls the particulate trap 10A.
(Or 10B) as a regeneration timing detecting means for detecting the elapsed time from the start of the regeneration, and when the detected time exceeds a preset value, the temperature becomes higher than the particulate combustion temperature. The on-off valves 9 and 32 may be opened. In this case, if the detected time exceeds a preset value, the on-off valve is opened assuming that the temperature has become equal to or higher than the burning temperature of the particulates. Can be facilitated. Further, the particulate trap device is provided with switching means 33.
However, the communication path 30 may be closed particularly when the engine speed during regeneration is higher than a predetermined value. In this case, the exhaust gas is not excessively supplied to the particulate trap 10A (or 10B), so that the melting of the particulate trap can be prevented.

Further, the particulate trap device is
The ECU 36 particularly has a function as a regeneration timing detecting means for detecting an elapsed time from the start of the regeneration of the particulate trap, and when the detected time exceeds a preset value, the temperature becomes higher than the particulate combustion temperature. The on-off valve 32 may be opened as a failure. In this case, in particular, when the detected time exceeds a preset value, the on-off valve is opened assuming that the temperature becomes higher than the burning temperature of the particulates, so that the supply of exhaust gas for incineration is made in a timely manner. Control can be facilitated.

Further, the particulate trap device is
An intermediate portion of the communication passage 45 is a first flow control passage 45 having a small diameter D1.
1 and a second on-off valve 4 that is formed in parallel with a large-diameter D2 second flow-regulating passage 452, and the on-off valve opens and closes the first flow-regulating passage.
1 and a second on-off valve 42 for opening and closing the second flow control passage. The ECU 50 sets the particulate trap 10A (or 10B) to a temperature equal to or higher than the particulate combustion temperature, and sets the operating state during regeneration to the first. If the rotation speed is equal to or lower than Ne1, the first and second on-off valves 41 and 42 are both opened, and the first
When the rotation speed is equal to or higher than Ne1 and equal to or lower than the second rotation speed Ne2, only the second on-off valve 42 may be opened, and when the rotation speed is equal to or higher than the second rotation speed Ne2, only the first on-off valve 41 may be opened. in this case,
Irrespective of the change in the operating range, the variation in the supply amount of the exhaust gas for incineration can be suppressed, the deterioration of the durability of the filter can be prevented, and the control can be simplified.

Further, the particulate trap device E
When the operating state during regeneration is less than or equal to the first rotation speed, the CU 50
If the first operating range E _{(A + B)} is equal to or less than the load, the first and second on-off valves 41 and 42 are both opened, and if the operating state is outside the first operating range and equal to or less than the second rotational speed, the second load is reduced. The following second operating range E
If it is _B is opened only the second on-off valve 42, the operating state is the first operating region E _{(A + B)} and the maximum load following third operating region at and below the maximum rotational speed than the second operating region E _B If it is E _a first
Only the on-off valve 41 may be opened. In this case, the variation in the supply amount of the exhaust gas for incineration can be suppressed more reliably irrespective of the change in the operation range, the durability of the filter can be reliably prevented from lowering, and the control can be facilitated.

[0050]

According to the present invention, the control means closes one of the first and second branch pipes holding the particulate traps which need to be regenerated by the output of the regeneration timing detecting means. The switching valve is actuated, the particulate trap regenerating means is actuated, and when the temperature of the particulate trap becomes equal to or higher than the particulate combustion temperature, the on-off valve of the communication passage is opened to bring the communication passage into communication. As a result, a part of the exhaust gas is supplied to the particulate trap requiring regeneration through the communication passage, and the particulates are burned by oxygen contained in the supplied exhaust gas. At this time, since the orifice is interposed in the communication passage, even when the on-off valve is fully opened, the exhaust gas supplied from the communication passage by the orifice has an amount capable of maintaining the particulate combustion temperature in an appropriate range. Is narrowed down to
For this reason, the amount of exhaust gas supplied to the particulate trap by the orifice is always an appropriate amount, the particulate is burned in an appropriate temperature range, the durability of the particulate trap can be maintained, and the cost increases due to the complicated configuration. Also does not invite. In particular, the on-off valve only needs to open and close the communication path, and there is no need for complicated valve on-off control for adjusting the amount of exhaust gas by changing the opening degree of the on-off valve itself. In addition, it prevents particulates and the like contained in the exhaust gas from accumulating on the on-off valve and making it impossible to always set the on-off valve to an appropriate opening degree, and to prevent the occurrence of such a problem that the on-off valve cannot be finely adjusted in flow rate. The effect that it can be obtained is also obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a particulate trap device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the particulate trap shown in FIG.

FIG. 3 is a flowchart of regeneration control of the particulate trap device shown in FIG.

FIG. 4 is a schematic configuration diagram of a particulate trap device according to a second embodiment of the present invention.

5 is an explanatory view of an enlarged flow path of a communication path in the particulate trap device of FIG. 4; FIG.
Indicates the respective states during low-speed reproduction, and (c) indicates the respective states during high-speed reproduction.

6 is an exhaust temperature-engine speed characteristic diagram used in the particulate trap device of FIG. 4;

FIG. 7 is a flowchart of regeneration control of the particulate trap device of FIG.

FIG. 8 is a schematic configuration diagram of a particulate trap device according to a third embodiment of the present invention.

FIG. 9 is a flowchart of a regeneration control of the particulate trap device of FIG. 8;

FIG. 10 is a schematic configuration diagram of a particulate trap device according to a fourth embodiment of the present invention.

11 is an enlarged cutaway cross-sectional view of first and second on-off valves used in the particulate trap device of FIG. 10 and a casing accommodating them.

FIG. 12 is a bottom view of the casing of FIG.

FIG. 13 is a sectional view of the casing of FIG. 11;

FIG. 14 is a bottom view of the casing of FIG.

FIG. 15 is a sectional view taken along line XX of FIG. 13;

FIG. 16 is a sectional view taken along line YY of FIG. 13;

FIG. 17 is a flowchart of regeneration control of the particulate trap device of FIG.

FIG. 18 is a perspective view of E of the particulate trap device of FIG. 10;
It is a characteristic line figure of an on-off valve map used by CU.

19 is a characteristic diagram of the regeneration rate-time of the particulate trap device of FIG.

FIG. 20 is a characteristic diagram of filter temperature-orifice area of the particulate trap device of FIG.

[Explanation of symbols]

Reference Signs List 1A particulate filter 1B particulate filter 6A electric heater 6B electric heater 5 communication passage 8 main exhaust pipe 8A first branch pipe 8B second branch pipe 9 on-off valve 10A first particulate trap 10B second particulate trap 11A, 11B heat Reflector 14 ECU 18 Switching valve 19 Switching valve 20 Orifice 21 Pressure sensor 22A Temperature sensor 22B Temperature sensor 30 Communication passage 31 Bypass passage 32 Opening / closing valve A 33 Switching valve B 34 Orifice 35 Orifice 36 ECU 40 ECU 41 1st opening / closing valve 42 First 2 opening / closing valve 41a air cylinder 42a air cylinder 43 first solenoid valve 44 second solenoid valve 45 communication passage 451 first flow adjustment path 452 second flow adjustment path 45a first connection port 45b second connection port 50 ECU 55 engine rotation Rolling speed sensor 56 load sensor E _{(A + B)} first operating region E _B second operating region E _A third operating region

Continuation of the front page (56) References JP-A-4-72441 (JP, A) JP-A-5-26028 (JP, A) JP-A-4-347316 (JP, A) JP-A-5-214924 (JP) JP-A-5-288039 (JP, A) JP-A-5-321637 (JP, A) JP-A-56-92318 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B01D 46/00-46/54 F01N 3/02-3/038

Claims (7)

(57) [Claims] An exhaust pipe, first and second branch pipes connected to the exhaust pipe, and first and second first and second branch pipes, each of which collects particulates in exhaust gas. A second particulate trap, a switching valve for opening and closing the first and second branch pipes on the upstream side of the particulate trap,
A communication passage connecting the first and second branch pipes through an orifice between the switching valve and the particulate trap, and a communication state provided between the communication passage and the communication passage, the communication passage being in a non-communication state;
Opening / closing valve for switching to a state, regeneration time detecting means for detecting the regeneration time of the particulate trap, and particulate trap regeneration for burning the particulates collected in the particulate trap to regenerate the particulate trap. Means, and the switching valve is operated so as to close the branch pipe on the side of the particulate trap which needs to be regenerated by the output of the regeneration timing detecting means, the particulate trap regenerating means is operated, and the particulate trap is operated. When the temperature rises above the particulate combustion temperature, open the on- off valve
Control means for setting the communication path to a communication state . 2. A switching means provided in said communication path, said switching means closing one of said communication path and said bypass path in accordance with an operation state at the time of regeneration, and a bypass path having a larger flow path resistance than said communication path. The particulate trap device according to claim 1, comprising: 3. The control means has a regeneration timing detecting means for detecting an elapsed time from the start of the regeneration of the particulate trap, and when the detected time exceeds a preset value, the particulate matter is trapped. The particulate trap device according to claim 1 or 2, wherein the on-off valve is opened when the temperature has reached a combustion temperature or higher. 4. The particulate trap apparatus according to claim 2, wherein said switching means closes said communication passage when the engine speed during regeneration is higher than a predetermined value. 5. The apparatus according to claim 1, wherein said control means has a regeneration timing detecting means for detecting an elapsed time from the start of regeneration of said particulate trap, and when the detected time exceeds a preset value, the particulate matter is trapped. 5. The particulate trap device according to claim 4, wherein the on-off valve is opened when the temperature becomes higher than the combustion temperature. 6. An intermediate portion of the communication passage is formed by arranging a small-diameter first flow regulating passage and a large-diameter second flow regulating passage in parallel, and the on-off valve opens and closes the first flow regulating passage. A first on-off valve and a second on-off valve for opening and closing the second flow regulating path,
The control means opens both the first and second on-off valves when the operating state at the time of regeneration is equal to or lower than the first rotation speed after the temperature of the particulate trap becomes equal to or higher than the burning temperature of the particulates. 2. The patty according to claim 1, wherein only the second on-off valve is opened when the rotation speed is equal to or more than one rotation speed and equal to or less than the second rotation speed, and when the rotation speed is equal to or more than the second rotation speed, only the first on-off valve is opened. Cured trap device. 7. The control means according to claim 1, wherein the operating state at the time of regeneration is the first.
The first and second on-off valves are both opened when the engine speed is in the first operating range below the first load at a rotational speed or less, and the operating state is other than the first operating region and is below the second rotational speed and below the second load. In the second operating range, only the second on-off valve is opened, and when the operating state is in the third operating range other than the first and second operating ranges and not more than the maximum rotation speed and not more than the maximum load, the first operating range is set. 7. The particulate trap device according to claim 6, wherein only the on-off valve is opened.