JPH0219534Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to an exhaust purification device for a diesel engine for vehicles, and in particular, the particulate components in the exhaust are collected by a filter member. This invention relates to an improvement in a device for burning and removing particulate components.

(Prior art) Generally, the exhaust gas of a diesel engine contains particulate components generated when part of the fuel decomposes due to the high temperature during the combustion process and part of the carbon is liberated. It is emitted as black smoke inside. For this reason, as part of the exhaust purification measures for diesel engines, a filter member with air permeability formed in a honeycomb shape made of ceramics or the like is placed in the exhaust passage of the engine, and while the exhaust gas passes through the filter member, the exhaust gas is An exhaust gas purification device that uses a filter member to collect mixed particulate components has already been developed.

When an engine is operated for a long period of time in an exhaust purification device equipped with such a filter member, the filter member becomes clogged due to the accumulation of particulate components, which increases the back pressure of the engine and causes a decrease in output. There is a problem.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 55-131518, an electric heating element made of nichrome wire or the like is attached to the filter member, and the electric heating element is energized periodically or when clogging occurs. It has been proposed to burn the particulate components deposited on the filter member and eliminate clogging of the filter member.

However, in this prior example, a large current is applied to the electric heating element, so it is difficult to energize the battery to electrical components that are connected in parallel with the electric heating element and are essential for the operation of the vehicle, especially the headlamp of an automobile. If this were to happen, the load on the battery would increase, causing an even larger current to flow, and the problem would be that the voltage drop due to the internal resistance of the battery would become too large to ignore. In other words, when such a large voltage drop occurs, the amount of current that can be taken out to the outside of the battery decreases, and the current flowing to essential electrical components such as the headlamp also decreases, reducing the illuminance of the headlamp. There was a problem.

(Purpose of the invention) The purpose of the invention is to reduce the amount of electricity supplied to specific electrical components that are essential for vehicle operation and have priority over the electric heating element that heats the filter member due to the voltage drop caused by the internal resistance of the battery. To provide an exhaust gas purification device for a diesel engine that allows specific electrical components to operate normally without causing any damage.

(Structure of the invention) The exhaust gas purification device for a diesel engine according to the invention has the following structure. That is, in a diesel engine exhaust purification system that burns and removes particulate components collected by a filter member disposed in the engine's exhaust passage with an electric heating element powered by a battery, it is possible to detect the operation of electrical components. An electrical component operation detection device is provided to detect the operating state of a specific electrical component among vehicle electrical components that is essential for vehicle operation, has priority over the electric heating element, and is energized using the battery as a power source. is provided so that when the specific electrical component is operated, the power supply to the electric heating element is stopped or the amount of current supplied is reduced to allow the specific electrical component to operate normally.

(Embodiments) <First Embodiment> A first embodiment of the present invention will be described with reference to FIG. A filter accommodating portion 2 is formed in an exhaust passage 1 of a diesel engine for a vehicle, that is, an automobile, as shown in FIG. is provided with a predetermined internal volume in a region where the temperature is high. Such a filter housing part 2
A filter member 3 that collects particulate components made of carbon in the exhaust gas is housed inside the filter member 3. This filter member 3 is made of porous ceramics with high air permeability called cordierite. It is formed into a honeycomb shape having a large number of small holes 3a and 3b penetrating through the pores. The upstream open ends of the small holes 3a of the filter member 3 are closed with blind plugs 4, and the downstream open ends of the remaining small holes 3b are closed with blind plugs 4. Exhaust gas flowing from the upstream side flows into the small hole 3b whose downstream open end is closed and the upstream side is open, and after particulate components are collected by the partition wall 3c, the upstream open end is closed and the downstream side is open. Small hole 3a
It is designed to be discharged to the downstream side of the exhaust passage 1 through the exhaust passage 1. Further, at the upstream end of the filter member 3, a heater 5, which is an electric heating element, is inserted through the blind plug 4 and into the small hole 3a. The heater 5 is made of nichrome wire, for example, and is energized to heat and burn particulate components deposited on the filter member 3 to remove them.

A bypass passage 6 is connected to the exhaust passage 1 and communicates the upstream side and the downstream side of the filter member 3 with the filter member 3 as a bypass. A bypass control valve 7 is inserted in the middle of the bypass passage 6, and the bypass passage 6 is opened and closed by the bypass control valve 7. One end of a pressure guide pipe 8 is connected to the bypass control valve 7 , and the other end of the pressure guide pipe 8 is connected to a vacuum pump 9 . In addition, a three-way valve 10 is located in the middle of the impulse pipe 8.
is inserted, and by switching the three-way valve 10, the negative pressure acting on the bypass control valve 7 is adjusted to open and close the bypass control valve 7. Furthermore, a temperature sensor A11 is inserted into the filter housing part 2 on the downstream side of the filter member 3 of the filter housing part 2, and this temperature sensor A1
1, the temperature of the exhaust gas on the downstream side of the filter member 3 is measured to detect whether or not the particulate components deposited on the partition wall 3c are burned away by the heater 5.

In the figure, 12 is a battery that is a power source mounted on the car. This battery 12 has a voltage of 12V, the negative pole side is grounded to the car body, and the positive pole side is connected to the bus bar 12a. There is. This bus bar 12a is connected in series to electrical components 16, such as a radio and a ventilation fan, which are not essential to the operation of the automobile, via a fuse 13, a key switch 14, and a relay A15. The relay A15 is turned ON and OFF by excitation, and is turned ON during normal operation, that is, when it is not energized, and turned OFF when it is activated, that is, when it is energized.
Also, between the fuse 13 and the key switch 14 is a light switch 1 which is an electrical component operation detection device.
7, a headlamp 18 is connected in parallel to the headlamp 18, which is an electrical component that is essential for driving the vehicle and has priority over the electrical component 16. When the light switch 17 is closed, the headlamp 18 is connected to the electrical component. It is designed to be energized with priority over 16.

The energizing line 5a of the heater 5 is connected in parallel to the downstream side of the headlamp 18 of the bus bar 12a, and the energizing line 5a is connected in series with a relay B19 and a relay C20 having an L contact and an R contact arranged in parallel. It is interposed. Further, a dropping resistor 21 is inserted between the R contact of the relay C20 and the relay B19, and the excitation coil 15a of the relay A15 is connected. is formed. In the relay C20, the L contact is normally in the ON state and the R contact is in the OFF state.The excitation coil 20a of the relay C20 is connected between the light switch 17 and the headlamp 18, and the excitation coil 20a is energized. In other words, when activated, the L contact turns OFF and the R contact turns ON.
It's starting to work. The excitation coil 19a of the relay B19 is connected to the operation control device 22.
The relay B19 is normally OFF when not energized, and turned ON when activated, ie energized.

The operation control device 22 includes the temperature sensor A1.
1 and the detection signal of the clogging sensor 23 are input. This clogging sensor 23 integrates fuel consumption, for example, and outputs a clogging detection signal when the fuel consumption reaches a set value. Based on both of the input signals, the operation control device 22 controls the excitation coil 19 of the relay B19 when the filter member 3 is clogged.
An energizing signal, that is, an excitation current is output to a, and the three-way valve 10 is operated to open and close the bypass control valve 7, and when the detection signal of the temperature sensor A11 exceeds a predetermined level, combustion of the particulate components is completed. When the clogging condition is resolved, the excitation current of the relay B19 is cut off.

The operation of the apparatus of the first embodiment configured as described above will be explained. First, the clogging sensor 23 detects the state in which particulate components are deposited on the filter member 3 and outputs a detection signal to the operation control device 22 . When the detection signal is input, the operation control device 22 activates the relay B.
An energizing signal, that is, an excitation current is applied to the excitation coil 19a of No. 19, and a switching signal is sent to the three-way valve 10 to open the bypass control valve 7, thereby controlling the upstream and downstream sides of the filter member 3 in the bypass passage 6. communicate. Then, when the relay B19 is energized and activated and turns ON, a current is passed through the L contact side of the relay C20 from the bus bar 12a to the current carrying wire 5a, and a large current is applied to the heater 5. is energized. Also, when the light switch 17 is closed and the head lamp 18 is turned on, the relay C2
0 excitation coil 20a is energized and relay C20
operates to open the L contact and close the R contact. In this state, the heater 5 is energized from the bus bar 12a through the dropping resistor 21, so the current energized to the heater 5 is reduced. Therefore, the total current flowing through the battery 12 is reduced, and when the heater 5 is energized, the battery 1
The voltage drop due to the internal resistance No. 2 is also reduced. That is, when lighting the headlamp 18, the relay C20, which is the energization control device, is operated to control the energization to the heater 5 via the drop register 21.
By doing so, a sufficient amount of current is supplied to the headlamp 18, and the illuminance of the headlamp 18 is maintained at a reference value or higher. Further, when the relay B19 is turned ON, current also flows to the excitation coil 15a of the relay A15, which activates the relay A15 and turns it OFF. When the relay A15 is turned OFF, the electric component 16 is no longer energized, and the voltage drop in the battery 12 due to the load current is significantly reduced. Therefore, a current flows through the headlamp 18 and the heater 5 in accordance with the original voltage of the battery 12, which is not affected by the voltage drop.

When the heater 5 continues to be energized, the filter member 3
The particulate components deposited on the filter member 3 are removed by combustion, and the filter member 3 is unclogged. At this time, the exhaust gas temperature downstream of the filter member 3 increases due to combustion of the particulate components. When the temperature sensor A11 detects this rise in the exhaust gas temperature and the exhaust temperature exceeds a set value, the temperature sensor A11 sends a detection signal to the operation control device 22. Operation control device 2
2 receives a detection signal from the temperature sensor A11, and when the temperature exceeds the set temperature continues for a predetermined period, it determines that the filter member 3 is unclogged and cuts off the energization signal, that is, the excitation current of the excitation coil 19a. When the excitation current is cut off, relay B1
9 returns to the normal OFF state, and relay B19
When the relay A15 becomes OFF, the excitation current no longer flows through the excitation coil 15a of the relay A15, and the relay A15 also returns to its normal ON state. Further, when the head lamp 18 is turned off, the excitation current of the excitation coil 20a of the relay C20 is also cut off, and the relay C20 returns to the normal state, with the L contact in the ON state and the R contact in the OFF state.

The device of the first embodiment as described above has the following effects. First, when the headlamp 18 is lit, relay C20 is activated, the L contact is turned OFF, and the R contact is turned OFF.
Since the ON operation is performed, the heater 5 is energized via the dropping resistor 21, so the amount of energization to the heater 5 is reduced. The amount of current supplied to the headlamp 18 is sufficiently ensured by reducing the amount of current supplied to the heater 5, thereby reducing the total load current, and thereby suppressing the voltage drop due to the internal resistance of the battery 12. In this way, headlamp 1
The illuminance of 8 is maintained above the reference value. Therefore, head lamps 18 are essential for driving a car.
can operate normally and improve vehicle safety.

In addition, when the heater 5 is energized, the relay A15 is also activated and turns off, so the energization to the electrical components 16 is also stopped.
It is possible to maintain the amount of electricity supplied to the device at a level greater than or equal to the reference value.

<Second Embodiment> A second embodiment of the present invention will be described with reference to FIGS. 2 to 4. In FIGS. 2 to 4, parts that are the same or corresponding to those in FIG. 1 are designated by the same reference numerals.

As shown in FIG. 2, this second embodiment utilizes a microcomputer, and is an operation control device such as a central processing unit (hereinafter referred to as CPU) 24.
It is now controlled by This CPU2
4 includes a clogging sensor 23, a temperature sensor A11,
The lighting signal 18a for the headlamp 18 is input from the light switch 17, which is an electrical component operation detection device, and the excitation current of the relay B19, which is the energization control device, is supplied to the excitation coil 19a from the CPU 24, and the excitation current is applied to the relay A15. The excitation coil 15a is energized.

As shown in FIG. 4, the CPU 24 includes a clogging detection section 25, a heater operation control section 26, a heater drive section 27, a clogging removal detection section 28, and a bypass control section 27a. First, the clogging detection section 25 detects clogging of the filter member 3 based on the detection signal from the clogging sensor 23, and the output signal from this clogging detection section 25 is input to the heater operation control section 26. It's becoming like that. This heater operation control section 26 receives a lighting signal 18 for the headlamp 18 from the light switch 17.
a is input, the headlamp 18 lights up,
When the headlamp 18 is turned off, an operation control signal for the heater 5 is output to the heater drive section 27 when the headlamp 18 is turned off. The operation control signal is also input to the clogging removal detection section 28, and the clogging removal detection section 28 detects when the heater is activated based on the exhaust temperature detection signal downstream of the filter member 3 from the temperature sensor A11. When the clogging is detected, a heater energization stop signal is output to the heater drive section 27, and if the clogging is not cleared even after a predetermined period of time has passed since the heater 5 is energized, an alarm signal 28a is output. ing. When the heater drive unit 27 is not input with the heater energization stop signal, the relay B is activated based on the operation control signal.
A energizing signal, that is, an excitation current is applied to 19 to turn on relay B19, and at the same time, relay A1
An excitation current is applied to the relay A15 to turn off the relay A15. Further, the excitation current of the relay B19 from the heater drive unit 27 is input to the bypass control unit 27a, and the bypass control unit 2
7a outputs a switching signal 10a for the bypass control valve 7, which opens the bypass control valve 7 when the filter member 3 is clogged and closes the bypass control valve 7 when the filter member 3 is clogged, based on the detection signal from the temperature sensor A11. I'm starting to do that.

The operation of the apparatus of the second embodiment configured as described above will be explained with reference to FIG. First, the CPU2
When the signal control in step 4 is started, in step 29
The entire CPU 24 is initialized, and in step 30 the detection signal from the clogging sensor 23 is input to the clogging detection section 25, and the process proceeds to step 31.
In this step 31, it is determined whether or not there is a clogging condition, and if it is a clogging condition, step 3
The process proceeds to step 2, and if there is no clogging, the process returns to step 30. In step 32, the activation signal of the light switch 17, that is, the headlamp 1 is activated.
The lighting signal 18a of No. 8 is input to the heater operation control section 26, and the process proceeds to step 33. In step 33, it is determined whether the headlamp 18 is on or off, and when the headlamp 18 is off, the process proceeds to step 34.
and proceed to step 35, where the head lamp 18
When lit, signal control ends. Step 34
The heater drive section 27 is connected to relay A15 and relay B1.
9 is activated, relay A15 is turned OFF, relay B19 is turned ON, and the process proceeds to step 36. In step 36, the clogging removal detection section 28
The detection signal of the temperature sensor A11 is inputted to the temperature sensor A11, and the process proceeds to step 37. In step 37, the clogging removal detection unit 28 determines whether or not the clogging has been removed. If the clogging has been removed, the process proceeds to step 38; if the clogging has not been removed, the process proceeds to step 39. Proceed to. Step 3
At step 8, the heater drive section 27 cuts off the excitation current and stops the operation of the relays A15 and B19, and then ends the signal processing. Then, in step 39, an alarm signal 28a is output to warn the driver that the clogging has not been cleared.

Also, in step 35, the bypass control section 27a
Then, the three-way valve 10 is switched to open the bypass control valve 7, and the process proceeds to step 39. In this step 39, the temperature sensor A11 is connected to the bypass control section 27a.
The detection signal is input, and the process proceeds to step 40. In step 40, the bypass control unit 27a determines whether the temperature T detected by the temperature sensor A11 has reached the set temperature To, and if T≧To... is established, the particulate component is combusted after a predetermined period of time. If it is determined that the equation has been completed, the process proceeds to step 41, and if the equation does not hold, the process returns to step 35. Then, in step 41, the bypass control section 27
In step a, the three-way valve 10 is switched to close the bypass control valve 7, and then the signal processing ends.

In the second embodiment described above, the CPU 24 stops energizing the heater 5 based on the lighting signal 18a of the headlamp 18, so that the voltage drop in the battery 12 is further suppressed, thereby ensuring the amount of energization to the headlamp 18. The illuminance of the headlamp 18 can be maintained above the reference value.

Note that the present invention is not limited to the above embodiments. For example, headlamp 1 is an essential electrical component for driving a car that has priority over heater 5.
The present invention is not limited to 8, and may be a vehicle interior heater for use in extremely cold regions. Further, the clogging sensor 23 is not limited to one that determines the clogging state based on fuel consumption, but also based on the distance traveled,
Engine operating time, resistance value change of filter components,
The determination can also be made by detecting back pressure of the engine.

(Effects of the invention) As explained above, according to the invention, the operation of a specific electrical component that is essential and given priority to vehicle operation is detected by the electrical component operation detection device, and when the specific electrical component is activated, Since the energization control device stops energizing or reduces the amount of energization to the electric heating element that heats the filter member, the specific electrical equipment is powered by the same battery as that used by the electric heating element. During operation, the voltage drop due to the internal resistance of the battery can be suppressed, and the amount of current supplied to the specific electrical component can be ensured to ensure normal operation, which has great effects.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the device of the present invention, FIGS. 2 to 4 are diagrams showing a second embodiment of the present invention, and FIG. 2 is a block diagram of the second embodiment of the device. FIG. 3 is a block diagram of the CPU 24 shown in FIG. 2, and FIG. 4 is a flowchart showing the operation of the second embodiment device. 1...Exhaust passage, 3...Filter member, 5...
Heater (electric heating element), 11...Temperature sensor A,
12...Battery (power supply), 15...Relay A,
16... Electrical equipment, 17... Light switch (electrical component operation detection device), 18... Head lamp (specific electrical component), 19... Relay B, 20... Relay C (energization control device), 21... Dropping register (energization control device), 22...operation control device, 2
3...Clogging sensor, 24...CPU (operation control unit).

Claims (1)

[Scope of utility model registration request] A vehicle in which a filter member is provided in the exhaust passage of the engine to collect particulate components in the exhaust gas, and an electric heating element is provided that burns and removes the particulate components collected by the filter member when energized using a battery as a power source. In an exhaust purification system for a diesel engine for a vehicle, among vehicle electrical components connected in parallel with the electric heating element to the battery, certain electrical components are essential for vehicle operation and have priority over the electric heating element. Equipped with an electrical component operation detection device that detects the operating state, and an energization control device that stops energizing the electric heating element or reduces the amount of energization when the specific electrical component is activated based on the output of the electrical component operation detection device. A diesel engine exhaust purification device featuring: