JPH03210013A - Exhaust gas particulate purification device of diesel engine - Google Patents

Abstract

PURPOSE:To every radiate high frequency wave to a surface of an inlet side of a filter by providing a direction changing means which changes proceeding direction of the high frequency output from a transmitting means and scatters it. CONSTITUTION:An exhaust gas particulate purification device 11 has a filter 17 which captures particulates in exhaust gas, and a transmitting means made up of a magnetron transmitter 15 which combusts the particulates and reactivates the filter 17 and a wave guide 16. A direction changing means 27 composed of a motor 28, a connecting member 29, a supporting member 30, and a reflection plate 31 is provided. High frequency output from the transmitting means is changed in proceeding direction and scattered by the direction changing means 27. The frequency is then irradiated to an end face 17a of the filter 17, that is, on the side of inflowing of the exhaust gas. The high frequency wave is radiated to the whole surface of the end face 17a with an even density while being scattered, and the particulates captured thereat are heated evenly.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to DPF (Diesel Particular
ate Fsi lte? ) is regenerated by a magnetron oscillator for a diesel engine exhaust particulate purification device.

[Conventional technology]

Diesel engines, which use low-cost diesel oil, have superior fuel efficiency compared to gasoline engines, so they are now being used not only in large vehicles but also in ordinary cars. However, the above diesel engine
SOF (S.

1ble Organic Fraction) and carbon particles such as 5OOT. Therefore, an exhaust particulate purification device that removes the above-mentioned particulates has become an important element in creating a low-pollution engine that protects the environment, as well as a device that improves the performance of a diesel engine.

Generally, the above-mentioned exhaust particulate purification device uses a filter such as a DPF made of ceramic in a honeycomb structure, and the particulates in the exhaust gas are collected and removed by this filter. It has become. However, the above filters become clogged due to the collection of fine particles. Therefore, conventional exhaust particulate purification devices burn the particulates using, for example, a filter regeneration device such as a burner or a heater, or an intake/exhaust throttle of the engine, to eliminate clogging of the filter.

[Problems to be Solved by the Invention] However, in the conventional diesel engine exhaust particulate purification device described above, in the case of a filter regeneration device using a burner, it is difficult to reliably burn the particulates collected in the filter to eliminate clogging. However, there are problems in that the structure of the burner etc. becomes complicated, leading to an increase in cost, and it is difficult to sufficiently improve the reliability when igniting the burner.

In addition, in the case of a filter regeneration device using a heater, it is possible to construct it at a lower cost than the case of the burner described above, but it is difficult for the flame to propagate in the radial direction of the filter, and it is difficult to reliably burn particulates. The problem is that it is difficult to

Furthermore, in the case of intake/exhaust throttling, it is necessary to raise the exhaust gas temperature to the extent that particulates can be combusted. Therefore, in this case, it is necessary to operate the diesel engine at high speed and high load, and there is a problem in that the operating conditions are subject to very severe restrictions.

As described above, the above-mentioned filter regeneration device and the conventional exhaust particulate purification device that regenerates the filter using intake and exhaust throttles each have their own problems, and have not yet been commercialized.

Therefore, recent exhaust particulate purification devices, for example, as disclosed in Japanese Patent Application Laid-Open No. 11414/1982,
A filter regeneration device using a magnetron oscillator, which has a completely different concept from the burner, heater, and intake/exhaust throttle described above, is used to eliminate clogging.

The above exhaust particulate purification device includes a magnetron oscillator that emits high frequency waves that selectively heats particulates as a filter regeneration device, and 1. The structure is equipped with a reflecting member that reflects the high frequency waves emitted from the magnetron oscillator, and the high frequency waves emitted from the magnetron oscillator are reflected by the reflecting member and irradiated onto the fine particles, thereby selectively and efficiently targeting only the fine particles. It is designed to heat and burn well.

By the way, it is desirable to irradiate fine particles with high-density radio frequency waves in order to start combustion early. Further, the particulates collected by the filter usually start burning from the intake port side of the filter, and the combustion gradually moves to the exhaust port side, so that they are incinerated. Therefore, in the exhaust particulate purification device, it is necessary to irradiate the entire surface of the inlet side of the filter with high frequency waves at a uniform density to regenerate the filter in a short time.

However, in the above exhaust particulate purification device, the magnetron oscillator is fixed, and the distance between the magnetron oscillator and the end face of the filter on the suction port side is uneven.

Therefore, the high frequency emitted from the magnetron oscillator is
The particles collected on the suction port side of the filter will not be irradiated with uniform density, leading to variations in the start timing of heating combustion in the longitudinal cross-sectional direction. This variation in the timing of the start of heating and combustion increases the possibility that unburned particulates will be generated in a part of the filter, and if unburned particulates remain, the filter will not be regenerated sufficiently. , the regenerated filter cannot be used efficiently.

Furthermore, in order to completely incinerate the particulates, it is necessary to irradiate the filter with high frequency waves, resulting in an increase in power consumption.

Therefore, in the present invention, high-frequency waves are uniformly irradiated onto the surface of the inlet side of the filter to prevent the generation of unburned particulates, as well as to shorten the incineration time and reduce power consumption. The purpose of the present invention is to provide an engine exhaust particulate purification device.

[Means to solve the problem]

In order to solve the above problems, an exhaust particulate purification device for a diesel engine according to the present invention includes a filter that collects particulates in exhaust gas, and a filter regeneration device that regenerates the filter by burning the particulates. In the exhaust particulate purification device for a diesel engine, the filter regeneration device includes an oscillation means consisting of a magnetron oscillator and a waveguide that output high frequency waves that burn particulates, and a direction in which the high frequency waves emitted from the oscillation means are changed. It is characterized by having a direction changing means consisting of a motor, a connecting member, a supporting member, and a reflecting plate to uniformly irradiate the end face of the filter on the side where the exhaust gas flows in with high frequency waves.

[For production]

According to the above configuration, the filter regeneration device has an oscillation means that outputs high frequency waves, and the high frequency waves output from this oscillation means can heat and burn the particulates collected by the filter. It has become. At this time, the high frequency waves are irradiated onto the end face of the filter on the side into which the exhaust gas flows, while the traveling direction is changed by the direction changing means and disturbed. Therefore, the end face of the filter is irradiated with high frequency waves at a uniform density due to the disturbance of the high frequency waves, and the fine particles collected on this end face part are
It will be heated evenly.

The uniformly heated particulates start burning at approximately the same time, and this combustion moves planarly within the filter and ends at the end face from which the exhaust gas flows out. At this time, the particulates collected by the filter are burned in a planar manner within the filter, so that they do not remain as unburned particulates (and, as a result, unnecessary high-frequency output can be eliminated, reducing the incineration time). It is possible to shorten the time and reduce power consumption.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

As shown in FIG. 1, the diesel engine exhaust particulate purification device 11 according to this embodiment
It is connected to the exhaust pipe 2 of. The above-mentioned diesel engine 1 has a combustion chamber 3 consisting of, for example, four pistons and cylinders, and each of these combustion chambers 3 and
An intake manifold 4 having an opening 4a for sucking air is provided on the fuel intake side. and,
The intake manifold 4 includes an air cleaner 5 that filters the air taken in from the opening 4a, a throttle 6 that adjusts the intake amount of the air filtered by the air cleaner 5, and a reflective member such as a wire mesh that reflects high frequencies. 22 are provided in this order. Note that this reflecting member 22 may be provided at the inlet 11a of the exhaust particulate purification device 11, which will be described later.

The diesel engine 1 is also provided with a drive shaft 7 that transmits the driving force generated in the combustion chambers 3, and this drive shaft 7 transmits fuel via a transmission member 8 such as a V-belt. It is connected to a fuel injection pump 9 that sends high pressure air to the combustion chambers 3 . . . and an air pump 10 that forcibly sends air to an exhaust particulate purification device 11 .

The air pump 10 described above includes a control unit (CPU) 1 which will be described later.
The electromagnetic clutch 12 has an electromagnetic clutch 12 controlled by the transmission member 8 and the air pump 1.
The drive of the air pump IO is controlled by arbitrarily disconnecting the air pump IO. The air pump 10 is also provided with an air pipe 14 that leads air to the exhaust particulate purifier 11. It is located in Further, on the exhaust port 11b side of the exhaust particulate purification device 11, a reflecting member 23 similar to the above-mentioned reflecting member 22 is provided, and a silencer 24 for reducing exhaust noise is provided.

The above exhaust particulate purification device 11 is provided with a filter I7 which is a DPF. This filter 17 is
Wall Flow is a ceramic material with a honeycomb structure that has micropores that communicate from the front surface to the back surface.
It is designed to collect particulates consisting of SOF, which is unburned particles, and SOOT, which is carbon particles, contained in the exhaust gas from a diesel engine. Note that the filter 17 described above may be of a ceramic foam type.

In addition, the exhaust particulate purification device 11 includes SOF・5OOT
An oscillating means serving as a filter regeneration device for burning particulates consisting of The waveguide 16 leading out to

The above high frequency is the induction heating frequency set in Class 611, 13.56Mc+0.05%, 27.12
Mc+0.6%, 40.68Mc+0.05%, 915
Mc±0.05%, 2,450Mc±50Mc, and 5,850Mc±75Mc. Among these frequencies for induction heating, the magnetron oscillator 15 mentioned above has 2,
It is designed to emit a high frequency of 450Mc±50Mc, which is the induction power frequency for heating. As a result, the high frequency waves emitted from the magnetron oscillation capacity 5 are transmitted to the outer wall of the exhaust particulate purification device 11 formed of metal and the reflecting members 22 and 2.
3, and is made of ceramic filter 1
7 is transparent.

The magnetron oscillator 15 that outputs the above-mentioned high frequency includes:
For example, multi-segment magnetrons such as a Lecher wire resonant four-segment anode magnetron and a cavity resonant eight-segment magnetron are used, and by arranging a Lecher wire of an appropriate length between the cathode and anode, the oscillating circuit can be created. It is formed. The output of this magnetron oscillator 15 is adjusted by moving the Lecher line by the control means 13, and the wavelength is adjusted within the range of 2,450 Mc±50 Mc by the voltage of the anode. .

Further, a direction changing means 27 for changing the traveling direction of the high frequency wave and disturbing the high frequency wave is disposed on the side in the traveling direction of the high frequency wave led out from the waveguide I6.

As shown in FIG. 2, this direction changing means 27 includes a reflecting plate 31 that reflects the high frequency waves derived from the waveguide 16, and a reflecting plate 31 that supports the reflecting plate 31 at its swing center so that it can reciprocate in six directions. It consists of a swinging support member 30, a connecting member 29 engaged with one end of this supporting member 30, and a motor 28 that reciprocates this connecting member 29 in the vertical direction.The motor 28 is driven by: This is performed by the control means 13 shown in FIG. Furthermore, the above reflection f! The position of the waveguide 31 is not limited as long as it is within the range where the high frequency wave derived from the waveguide 16 is irradiated.

The center of oscillation of the reflecting plate 31 is located at the exhaust particulate purification device 1.
The waveguide 16 is located closer to the filter 17 than the joint 16a between the outer wall of the waveguide 16 and the waveguide 16. , the end face 1 of the filter 17 which is the exhaust gas inflow side
Irradiation is made uniformly from the top to the bottom of 7a.

Further, on the same side as the direction changing means 27, as shown in FIG.
An exhaust pressure sensor 18 detects the pressure on the a side and detects the oxygen concentration. The exhaust pressure sensor 18 and the 0□ sensor 19 are connected to the control means 13. Furthermore, an exhaust pressure sensor 20 and an 0□ sensor 21 similar to the exhaust pressure sensor 18 and 02 sensor 19 described above are connected to this control means 13, and these exhaust pressure sensors 20 and 02 sensor 21 It is provided on the exhaust port 11b side of the particulate purifier 11.

As a result, the control means 13 controls the exhaust particulate purification device 11.
By inputting the exhaust pressure and oxygen concentration at the suction port 11a side and the discharge port 11b side, the combustion state of particulates and the clogging state of the filter 17 can be recognized. In addition to the above-mentioned exhaust pressure and oxygen concentration, the control means 13 also includes the diesel engine 10 rotation speed, load, intake temperature,
Water temperature and oil temperature are input as operating data.

In the above configuration, the operation of regenerating the filter 17 of the exhaust particulate purification device 11 will be described below.

First, as shown in FIG. 1, exhaust gas temperature, rotation speed, load, oil temperature, water temperature, intake temperature, and exhaust pressure are input as operating conditions to the control means 13, and based on the above exhaust pressure, for example, It is determined whether the filter 17 is active during regeneration. and,
During playback, an operation signal is output from the control means 3 to the motor 28, and the motor 28 causes the connecting member 29 to reciprocate in the vertical direction, as shown in FIG. This reciprocating movement causes the support member 30 engaged with the connecting member 29 to swing, and the reflection plate 31 supported by the support member 30 to swing in the A direction.

The oscillated reflection ItJi 31 reflects the high frequency wave emitted from the magnetron oscillator 15. At this time, the traveling direction of the reflected high frequency waves is continuously changed depending on the inclination angle of the reflection plate 31 with respect to the longitudinal direction of the waveguide 16. Therefore, the above high frequency is filtered by filter 1
The end surface 17a of 7 is uniformly irradiated from the top to the bottom.

In the filter 17, fine particles are collected from the upper part to the lower part and from the inlet port 11a side to the outlet port 11b side, and high frequency waves are collected on the inlet port 11a side, which is shorter from the magnetron oscillator 15. The particles are irradiated with high density. At this time, the high frequency waves are uniformly irradiated from the top to the bottom of the end surface 17a of the filter 17 by the reflection plate 31, and the particles are uniformly heated on the end surface 17a on the suction port 11a side.

Therefore, the combustion of fine particles occurs at the end surface 17a on the suction port 11a side.
The combustion that occurred in a planar manner will propagate from the intake port 11a side to the exhaust port 11b side along with the flow of exhaust gas, and will end at the exhaust port llb side at approximately the same time. Become.

At this time, while the above combustion is being performed, the control means 13 controls the oxygen concentration detected by both the 02 sensors 19 and 20 provided on the inlet lla side and the outlet 11b side of the exhaust particulate purification device 11. I'm monitoring it. And the suction port 11a
If the oxygen concentration on the side is below a certain value, the air pump 10
is driven to send air into the exhaust particulate purification device 11, and this air is used for combustion of particulates.

On the other hand, when the fine particles on the exhaust port 11b side burn and incineration is completed, the oxygen concentrations on the intake port 11a side and the exhaust port 11b side become equal, and the control means 13 to which these oxygen concentrations are input, Once the incineration of the particulates has been completed, the operation of the magnetron oscillator 15 and air pump 10 is stopped. As a result, the regeneration of filter (7) in the exhaust particulate purification device is completed.

In this way, the exhaust particulate purification device of the present embodiment disturbs the high frequency waves with the direction changing means 27, so that the filter 17
The irradiation of high frequency waves to the filter 17 is uniformized in a planar manner, and the combustion of particulates is caused to occur approximately at the same time on the end face 17a of the filter 17 on the suction port 11a side. As a result, the exhaust particulate purification device allows combustion to proceed from the intake port 11a side to the exhaust port 11b side.
By performing the regeneration in a planar manner toward the side, it is possible to prevent the generation of unburned particulates, and the time required for regeneration is shortened because the combustion of particulates on the exhaust port 11b side ends at approximately the same time. will be done. Furthermore, the exhaust particulate purification device does not require extra high-frequency irradiation to prevent unburned particulates from remaining, making it possible to reduce power consumption.

In this embodiment, the reflection plate 31 is disposed closer to the filter 17 than the joint 16a of the waveguide 16, but the present invention is not limited thereto.

That is, as shown in FIG. 3, the reflecting plate 31 may be arranged such that the center of swing is located at the center of the joint portion 16a. In this case, the reflection plate 31 can be aligned with the outer wall of the exhaust particulate purification device 11, and can be used as a lid for the waveguide 16. Thereby, in addition to the above-mentioned high-frequency disturbance, the reflector plate 31 can be used as a lid when the filter 17 is not regenerated, and can protect the magnetron oscillator 15 from exhaust gas.

Next, a modification of the exhaust particulate purification device will be shown.

The direction changing means 27 provided in the exhaust particulate purification device is
As shown in FIG. 4, a reflection plate 31 is disposed at the connection between the exhaust pipe 2 and the exhaust particulate purification device 1, and the waveguide 1
6 is arranged so as to irradiate high frequency waves onto this reflecting plate 31. As a result, the high frequency waves emitted from the magnetron oscillator 15 are transmitted to the reflection plate 3 which swings back and forth in the C direction.
1, the light is reflected in the direction of the filter 17 and is disturbed, so that the end surface 17a of the filter 17 is uniformly irradiated.

At this time, in the filter 17 described above, a reflection plate 31 is disposed at the central portion of the filter 17, at the connection portion between the exhaust pipe 2 and the exhaust particulate purification device 11. Therefore, the high frequency waves reflected by the reflector 31 are more uniformly irradiated onto the filter 17, and the timing of planar combustion of the fine particles becomes more equal.

Further, by adjusting the angle of the reflecting plate 31, it is possible to change the direction in which the exhaust gas heads toward the filter 17. Therefore, the exhaust particulate purification device can control the direction of the exhaust gas, thereby making it possible to further uniformize the heating of the particulates.

Furthermore, in addition to the above-mentioned high frequency disturbance, the reflection plate 31
It can also be used as an exhaust throttle valve to throttle exhaust gas from the exhaust pipe 2. For example, if a misfire occurs at the start of operation and white smoke is produced, the reflector plate 31 can be used as an exhaust throttle valve to throttle exhaust gas from the exhaust pipe 2.
By rotating it so as to block it and suppressing the outflow of exhaust gas, it is possible to prevent the generation of white smoke due to misfires, etc.

〔Effect of the invention〕

As described above, the diesel engine exhaust particulate purification device according to the present invention includes an oscillating means for outputting a high frequency wave for burning particulates, and a disturbance by changing the traveling direction of the high frequency wave emitted from the oscillating means. The filter also includes a direction changing means for uniformly irradiating high frequency waves onto the end face of the filter on the side into which exhaust gas flows.

As a result, the direction of the high frequency waves from the oscillation means is changed and disturbed by the direction changing means, so that the end face of the filter on the side where the exhaust gas flows in is irradiated with uniform density, and this end face part is irradiated with uniform density. The collected fine particles start burning in a planar shape at approximately the same time and move within the filter,
Since no unburned particulates remain and unnecessary high-frequency output is unnecessary, the incineration time can be shortened and power consumption can be reduced.

[Brief explanation of drawings]

1 to 4 show one embodiment of the present invention. FIG. 1 is a schematic configuration diagram of an exhaust particulate purification device for a diesel engine. FIGS. 2 to 4 are explanatory diagrams showing a state in which the reflecting plate of the direction changing means is oscillated. 1 is a diesel engine, 2 is an exhaust pipe, 3 is a combustion chamber, 4
10 is an intake manifold, 10 is an air pump 11 is an exhaust particulate purification device, 13 is a control means, 14 is an air pipe, 5 is a magnetron oscillator (oscillation means), 16 is a waveguide (oscillation means), 17 is a filter 8. 20 is an exhaust pressure sensor,
I9 and 21 are 0□ sensors, 22 and 23 are reflective members, and 27
is a direction changing means, 28 is a motor, 29 is a connecting member, 30
1 is a supporting member, and 1 is a reflecting plate.

Claims (1)

[Scope of Claims] 1. A diesel engine exhaust particulate purification device comprising a filter that collects particulates in exhaust gas and a filter regeneration device that burns the particulates to regenerate the filter, the filter regeneration device The system includes an oscillating means that outputs high frequency waves that burn particulates, and a direction that changes and disturbs the traveling direction of the high frequency waves emitted from this oscillating means, and uniformly irradiates the end face of the filter on the side where exhaust gas flows in with the high frequency waves. 1. An exhaust particulate purification device for a diesel engine, comprising changing means.