JP2878113B2 - Backwashing particulate collection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for collecting particulates in exhaust gas from a vehicle engine by a filter. More specifically, the present invention relates to a particulate collection device that can regenerate a filter by removing particulates collected by the filter from the filter with compressed air and backwashing the filter.

[0002]

2. Description of the Related Art Conventionally, as this type of backwash type particulate collection device, a collector containing a filter is provided in the middle of an exhaust pipe connected to an exhaust manifold of a vehicle engine, and one end is provided in an air tank. A backwash valve that opens and closes the air injection pipe is provided in the middle of the air injection pipe connected and the other end connected to the exhaust pipe downstream of the filter from the filter, and further provided on the exhaust pipe downstream of the air injection pipe from the air injection pipe. 2. Description of the Related Art There is known a particulate trapping device in which a provided shut-off valve opens and closes an exhaust pipe. In this trapping device, the filter is backwashed at a predetermined time interval. When the filter is backwashed, the shutoff valve is closed and then the backwash valve is opened to inject compressed air from the air injection pipe. As a result,
The particulates accumulated on the filter by the compressed air are blown off and separated from the filter. Further, the particulates separated from the filter are incinerated by a heater in a soot storage chamber provided at a lower portion of the collector.

[0003]

However, in the above-mentioned conventional backwashing type particulate collecting apparatus, when the filter is backwashed when the vehicle is stopped or running at a low speed and the engine noise is relatively low, the filter is removed from the air injection pipe. There was a problem that abnormal noise generated when the flow velocity of the compressed air blown toward the filter exceeded the speed of sound became annoying. Further, in the above-mentioned conventional collecting device, when the vehicle runs at a high speed or under a high load, the temperature of the filter becomes high. Immediately after that, when the vehicle is stopped or running at a low speed, the filter is backwashed. After that, the compressed air discharged from the exhaust pipe may have a relatively high temperature. Furthermore, in the above-mentioned conventional collecting device, when the filter is backwashed in a state where the pressure of the compressed air in the air tank is not sufficiently increased, the flow velocity of the compressed air injected from the air injection pipe toward the filter is sufficiently large. In addition, there is a problem that it is not possible to remove all of the particulates attached to the filter.

SUMMARY OF THE INVENTION It is an object of the present invention to prevent abnormal noise generated at the time of back washing of a filter from causing harshness, and compressed air for back washing discharged from an exhaust pipe stays in the air at a relatively high temperature. It is an object of the present invention to provide a backwashing type particulate trapping device which can prevent the compressed air in the air tank from being wasted.

[0005]

A configuration of the present invention for achieving the above object will be described with reference to FIG. 1 corresponding to an embodiment. The present invention includes a collector 14 provided in the middle of an exhaust pipe 13 connected to an exhaust manifold 12 of an engine 11 of a vehicle, a filter 16 contained in the collector 14 and collecting particulates in exhaust gas. , One end is air tank 21
An air injection pipe 19 whose other end is connected to the exhaust pipe 13 or the collector 14 on the downstream side of the exhaust gas from the filter 16 and can inject compressed air in the air tank 21 to the filter 16;
A backwash valve 22 provided in the middle of the air injection pipe 19 and capable of opening and closing the air injection pipe 19; a shut-off valve 23 provided on the exhaust pipe 13 downstream of the air injection pipe 19 on the exhaust gas side and capable of opening and closing the exhaust pipe 13; A backwashing type particulate collection device configured to close the shutoff valve 23 when the filter 16 is backwashed and then open the backwash valve 22 to inject compressed air from the air injection pipe 19. is there. Its characteristic configuration is a vehicle speed sensor 2 for detecting the speed V of the vehicle.
9, the temperature sensor 3 for detecting the temperature H _F of the filter 16
1 and a controller 33 for controlling the shutoff valve 23 and the backwash valve 22 based on the detection outputs of the vehicle speed sensor 29 and the temperature sensor 31. Further, a pressure sensor 32 for detecting the pressure _PT of the compressed air in the air tank 21 is provided, and the controller 33 controls the shut-off valve 23 and the backwash valve based on the detection outputs of the vehicle speed sensor 29, the temperature sensor 31, and the pressure sensor 32. It is preferred to be configured to control 22.

[0006]

When the engine 11 is started and the vehicle speed V and the pressure _PT in the air tank 21 exceed a predetermined value, the shut-off valve 23 is closed and the backwash valve 22 is opened for a predetermined time. Toward the air tank 21
Injects compressed air inside. At this time, the flow velocity of the compressed air exceeds the sound speed and generates an abnormal noise. However, since the engine sound is relatively loud, the abnormal noise does not become annoying. When the shutoff valve 23 is opened immediately after the backwash, the engine 11
The particulates in the exhaust gas discharged from the filter 16 are collected by the filter 16, and when a predetermined amount or more of the particulates accumulates on the filter 16, the controller 33 determines the vehicle speed V.
The filter 16 is backwashed on condition that the pressure _{PT of the} air tank 21 is equal to or higher than a predetermined value. Engine 11 immediately after the start, or when a predetermined amount or more of particulates deposited on the filter 16, the filter temperature H _F also the vehicle speed V is less than the predetermined value is smaller than a predetermined value, the controller 33
Backwashes the filter 16. This is a relatively low filter temperature H _F, the temperature of the compressed air used to backwash the filter 16 is not so much increased, the compressed air is hot air around be released in the atmosphere at the time of low-speed running This is because there is no stagnation.

[0007]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 to 3, one end of an exhaust pipe 13 is connected to the exhaust manifold 12 of the engine 11,
A collector 14 is provided in the exhaust pipe 13. The engine 11 is a diesel engine mounted on a vehicle (not shown) such as a truck or a bus. The collector 14 is the exhaust pipe 1
A pair is provided in parallel in the middle of 3 and these collectors 14 are formed in the same shape. Only one collector 14 of the pair of collectors 14 is shown, and the other collector is not shown.
Hereinafter, one collector 14 will be described, and description of the other collector will be omitted. The collector 14 is a filter 16
, A filter chamber 14a accommodated through a sealing material (not shown), an introduction chamber 14b provided above the filter chamber 14a to introduce exhaust gas of the engine 11, and a filter chamber 1
An exhaust chamber (not shown) provided on one side surface in the width direction of 4a and into which exhaust gas passing through the filter 16 flows, and a soot storage chamber provided below the filter chamber 14a where particulates separated from the filter 16 accumulate. 14c. The filter 16 is formed of a porous heat-resistant ceramic material in a rectangular parallelepiped shape, and traps particulates in exhaust gas. The filter 16 is referred to as a cross-flow filter in this example. Exhaust gas flows in from the upper surface of the filter 16, passes through the filter 16, and after particulates are collected, is discharged from one side in the width direction of the filter 16. It has become so. A heater 17 is inserted into the soot storage chamber 14c, and the heater 17 is electrically connected to a battery 18.

The exhaust pipe 13 has one end connected to the exhaust manifold 12 of the engine 11 and the other end connected to the introduction chamber 14 of the collector 14.
b and one end of the collector 1
Downstream exhaust pipe 1 connected to the discharge chamber 4 and open at the other end
3b. One end of the air injection pipe 19 is inserted into the downstream exhaust pipe 13 b near the discharge chamber, and the inserted tip is bent toward the filter 16. The other end of the air injection pipe 19 is connected to an air tank 21 for storing compressed air, and a backwash valve 22 is provided in the air injection pipe 19. The backwash valve 22 has a seat valve (not shown) fixed to the diaphragm and a valve seat capable of seating the seat valve. The pulse valve can be fully opened instantaneously, and a three-port two-position switching spring for opening and closing the pulse valve. A return-type solenoid valve. When the solenoid valve is turned on, the air injection pipe is opened, and when the solenoid valve is turned off, the air injection pipe is shut off.

In the downstream exhaust pipe 13b, the exhaust pipe 13b is located downstream of the portion where the air injection pipe 19 is inserted.
Is provided with a shut-off valve 23 that can be opened and closed. The shut-off valve 23 is a valve for an exhaust brake. The shut-off valve 23 has a valve body 23a and a support shaft 23b that rotatably supports the valve body 23a. The support shaft 23b is connected to a piston rod 24a of a spring return type air cylinder 24 via a link 26. You. The air cylinder 24 is connected to the air tank 21 via an air supply pipe 27, and an opening / closing valve 28 is provided in the air supply pipe 27. The on-off valve 28 is a spring return type solenoid valve that switches between three ports and two positions. On-off valve 2
When 8 is turned on, the compressed air is supplied to the air cylinder 24, and the piston rod 24a protrudes, so that the shut-off valve 23 rotates in a direction to shut off the downstream side exhaust pipe 13b. When the on-off valve 28 is turned off, the compressed air in the air cylinder 24 is exhausted, and the piston rod 2 is repelled by the elastic force of a spring (not shown) built in the air cylinder 24.
By retracting 4a, the shut-off valve 23 rotates in a direction to open the downstream side exhaust pipe 13b.

The characteristic configuration of this embodiment is that the vehicle speed V
Speed sensor 29 for detecting the temperature, and the temperature H _{F of the} filter 16
, A pressure sensor 32 for detecting the pressure P _T of the compressed air in the air tank 21, a shut-off valve 23 and a reverse valve based on the output of the vehicle speed sensor 29, the temperature sensor 31 and the pressure sensor 32. A controller 33 for controlling the valve washing 22 is provided. The vehicle speed sensor 29 is provided near a main shaft 34a protruding from the rear end of the transmission 34, and detects the rotation speed of the main shaft 34a. Temperature sensor 31 is inserted toward the collector 14 top filter 16 detects the temperature H _F in the filter 16 housed in the filter chamber 14a. The engine rotation sensor 36 for detecting the rotational speed N _E of the crank shaft 11a in the vicinity of the crank shaft 11a is provided projecting from the front end of the engine 11, detects the amount of depression of the pedal 37 is in the vicinity of an accelerator pedal 37 An engine load sensor 38 is provided.

The respective detection outputs of the vehicle speed sensor 29, temperature sensor 31, pressure sensor 32, engine rotation sensor 36 and engine load sensor 38 are connected to the input of a CPU 33b via an input interface 33a of a controller 33 comprising a microcomputer. Is connected to the backwash valve 22 and the on-off valve 28 via the output interface 33c and the drive circuit 39. Although not shown a differential pressure sensor for detecting the pressure loss P _E provided by the filter 16 before and after the exhaust pipe 13 is formed by resistance wire strain gauge or a piezoelectric element or the like flue gas stream collector 14, a differential pressure sensor Is connected to the input interface 33a. The memory 41 is connected to the CPU 33b. When particulate filter 16 come deposited, but the pressure loss P _E detected by the differential pressure sensor is gradually increased, the pressure loss P _E is the rotational speed N _E and the load W _E of the engine 11 It changes with the change in the determined exhaust gas flow rate. The memory 41 when it becomes a predetermined amount of particulates deposited on the filter 16 has to backwash, limit the pressure loss P _E 'is stored as a map for the rotational speed N _E and the load W _E of the engine 11 .

[0012] the timer T ₁ to set the time until the backwashing first filter 16 after starting the engine 11 in CPU33b, and the timer T ₂ to set the maximum interval time thereafter backwashing filter 16 Connected. The timers T ₁ and T ₂ are 10 minutes and 60 minutes in this example, respectively. Timer T ₂ are when the pressure loss P _E of the filter 16 of the exhaust gas flow becomes higher limit pressure loss P _E ', the vehicle speed V is 30 km / filter temperature H even during low speed of less than a time
_{If F} is less than 300 ° C., the time for forcibly backwashing the filter 16 is set.

The operation of the thus constructed backwashing type particulate collecting apparatus will be described. When starting the engine 11, the controller 33 actuates and resets a timer T _1. Since the amount of particulates deposited on the filter 16 immediately before the start of the engine 11 varies, the controller 33 determines that the vehicle speed V is 30 km / h or more by the vehicle speed sensor 29 and that the pressure _PT in the air tank 21 is 6 kg / cm by the pressure sensor 32. ^{When two} or more are detected, the shut-off valve 23 is closed to shut off the downstream exhaust pipe 13b. In this state, the backwash valve 22 is opened for a very short predetermined time, and the air tank is moved from the air injection pipe 19 toward the filter 16 to the air tank. The compressed air in 21 is injected. When the compressed air is injected, the flow velocity of the compressed air exceeds the sound speed and generates an abnormal noise. However, since the engine sound is relatively loud, the abnormal noise does not cause annoyance. When the shut-off valve 23 is opened after the backwash, abnormal noise is generated due to sudden pressure fluctuations before and after the valve 23, but it does not cause any annoyance for the same reason as described above. The compressed air is injected into the filter 16
Are separated from the filter 16 and accumulate in the soot storage chamber 14c, and the particulates are incinerated by the heater 17.

Immediately after the backwash, the controller 33 sets the timer T ₂
Reset and operate. Exhaust gas discharged from the engine 11 is exhausted by an exhaust manifold 12 and an upstream exhaust pipe 13a.
Flows into the introduction chamber 14b of the collector 14 through the passage. When the exhaust gas flowing into the introduction chamber 14b passes through the filter 16 of the filter chamber 14a, particulates in the exhaust gas are collected by the filter 16 and then pass through a discharge chamber (not shown) and a downstream exhaust pipe 13b. Released to the atmosphere. Controller 33 (not shown) a differential pressure sensor, based on the detection output of the engine rotation sensor 36 and the engine load sensor 38, the pressure loss by the filter 16 of the exhaust gas stream P _E of the engine rotational speed N is stored in the memory 41 _E and 'compared to the pressure loss P _E limit pressure loss P _E' limit pressure loss P _E for the engine load W _E when it becomes more, or the pressure loss P _E be less than or equal to limit pressure loss P _E ' Timer T ₂
When the vehicle speed V is 30 minutes,
Back washing is performed on condition that the pressure _PT in the air tank is 6 kg / cm ² or more and km / h or more. If the vehicle speed V is 30 km / hour or more, even the filter temperature H _F is 300 ° C. or higher, the filter 16 is backwashed. This is because even if the compressed air used for the backwashing of the filter 16 is released into the atmosphere in a state where the compressed air comes in contact with the high-temperature filter 16 and becomes high in temperature, it is quickly diffused without stagnation in the atmosphere. .

Meanwhile, immediately after the engine 11 starts, or when a predetermined amount or more of particulates deposited on the filter 16, also the vehicle speed V is less than 30 km / h, the filter temperature H _F is 300 ° C. or less and the timer T ₁ Is measured for 10 minutes or more, the controller 33 backwashes the filter 16. Further, even timer T ₁ at filter temperature H _F is 300 ° C. or less is less than 10 minutes, if the vehicle speed V is 10 km / hour or more, the controller 33 backwashing filter 16. Since the filter temperature H _F at this time is relatively low, the filter 1
The temperature of the compressed air used for backwashing in Step 6 does not rise so much, and even if this compressed air is released to the atmosphere during low-speed running, high-temperature air does not stagnate around. Further, when the pressure _PT in the air tank 21 is less than 6 kg / cm ² , the controller 33 does not backwash the filter 16, so that the compressed air in the air tank 21 can be prevented from being wasted.

In the above embodiment, the other end of the air injection pipe is inserted into the downstream exhaust pipe downstream of the filter, but this is merely an example, and may be connected to the discharge chamber of the collector. Further, in the above-described embodiment, a so-called cross-flow type filter in which exhaust gas flows in from the upper surface of the filter, passes through the filter, and particulates are collected, and then discharged from one side in the width direction of the filter has been described. However, the present invention is not limited to this, and the present invention may be applied to a so-called wall flow type filter in which a partition wall through which the exhaust gas passes to collect particulates extends in the exhaust gas flow direction. In the above embodiment, the pressure sensor for detecting the pressure of the compressed air in the air tank is provided in addition to the vehicle speed sensor for detecting the speed of the vehicle and the temperature sensor for detecting the temperature of the filter. The pressure sensor is not needed if it does not almost fall below. Further, in the above-described embodiment, the backwashing type particulate collection device in which a pair of collectors are provided in parallel in the middle of the exhaust pipe is described, but a single collector is provided in the middle of the exhaust pipe. A backwashing type particulate collection device may be used. In this case, when the shut-off valve is closed, the torque of the engine is reduced. However, since the time during which the shut-off valve is closed is as short as less than 1 second, there is almost no problem.
Further, the vehicle speed V, the filter temperature H _F ,
Timer T _1, the timer T _2, numerical values such as a pressure P _T of the air tank is one example, but is not limited thereto.

[0017]

As described above, according to the present invention, the backwash valve provided in the middle of the air injection pipe opens and closes the air injection pipe, and is provided in the exhaust pipe on the exhaust gas downstream side of the air injection pipe. A shutoff valve opens and closes an exhaust pipe, and a controller controls the shutoff valve and the backwash valve based on respective detection outputs of a vehicle speed sensor for detecting a vehicle speed and a temperature sensor for detecting a temperature of a filter. Therefore, the controller backwashes the filter except when the vehicle is stopped or running at a low speed with a relatively low engine sound, so that it is possible to prevent the abnormal noise generated at the time of backwashing the filter from being annoying. When the vehicle is stopped immediately after high-speed traveling or high-load traveling or traveling at low speed, the filter is at a high temperature.When the vehicle speed exceeds a predetermined value or when the filter temperature falls below a predetermined value, the controller activates the filter. Backwash.
As a result, it is possible to prevent the compressed air for backwash discharged from the exhaust pipe from staying in the atmosphere at a relatively high temperature. Further, by providing a pressure sensor for detecting the pressure of the compressed air in the air tank, the controller is configured to control the shut-off valve and the backwash valve based on each detection output of the vehicle speed sensor, the temperature sensor, and the pressure sensor, When the pressure of the compressed air in the air tank is less than the predetermined value, the filter is not backwashed, so that the compressed air in the air tank can be prevented from being wasted.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a backwashing type particulate collecting apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the first half operation of the device.

FIG. 3 is a flowchart showing the latter half operation of the device.

[Explanation of symbols]

11 of the engine 12 exhaust manifold 13 exhaust pipe 14 collector 16 filter 19 air blasting pipe 21 air tank 22 reversing valve 23 shut-off valve 29 a vehicle speed sensor 31 temperature sensor 32 pressure sensor 33 in the controller V vehicle speed H _F filter temperature P _T air tank pressure

Claims (2)

(57) [Claims] An exhaust manifold (1) for an engine (11) of a vehicle.
The collector (1) provided in the middle of the exhaust pipe (13) connected to (2)
4), a filter (16) housed in the collector (14) for collecting particulates in the exhaust gas, and an air tank (2) at one end.
1) and the other end is connected to the exhaust pipe (13) or the collector (14) on the exhaust gas downstream side of the filter (16) and the compressed air in the air tank (21) is connected to the filter (16). An air injection pipe (19) capable of injecting, a backwash valve (22) provided in the middle of the air injection pipe (19) and capable of opening and closing the air injection pipe (19),
A shut-off valve provided on the exhaust pipe (13) on the exhaust gas downstream side from the air injection pipe (19) and capable of opening and closing the exhaust pipe (13)
(23), when the filter (16) is backwashed, the shutoff valve (23) is closed and then the backwash valve (22) is opened to inject the compressed air from the air injection pipe (19). In the backwashing type particulate collection device configured to perform, a vehicle speed sensor (29) for detecting the speed (V) of the vehicle, and a temperature sensor (31) for detecting the temperature (H _F ) of the filter. A controller (33) for controlling the shut-off valve (23) and the backwash valve (22) based on each detection output of the vehicle speed sensor (29) and the temperature sensor (31) , wherein the vehicle speed sensor (29) detected a vehicle speed (V) that is equal to or higher than a predetermined value
When said controller (33) is said shut-off valve
(23) is closed and the backwash valve (22) is opened, and the temperature sensor is turned on regardless of the detection output of the vehicle speed sensor (29).
When (31) detects a temperature below a predetermined value, the control
Roller (33) closes the shut-off valve (23) and
A backwash-type particulate collection device, characterized in that the backwash valve (22) is opened . 2. The pressure (P _T ) of the compressed air in the air tank (21).
Pressure sensor (32) for detecting vehicle speed , a vehicle speed sensor (29) detects a vehicle speed (V) equal to or higher than a predetermined value, and
The pressure sensor (32) detects a pressure (P _T ) that is equal to or higher than a predetermined value.
Controller (33) closes the shut-off valve (23)
And the backwash valve (22) is opened, and the pressure sensor (32) detects a pressure (P _T ) less than a predetermined value .
When the controller (33) does not backwash the filter (16)
2. The backwashing type particulate trap according to claim 1, which is configured as described above.