KR20230140066A - Apparatus for after-treatment of exhaust gas - Google Patents

Abstract

An exhaust gas after-treatment device that can reduce stress caused by inrush current of switches and loads connected to a power source is disclosed. According to one aspect, an exhaust gas post-treatment device for post-processing exhaust gas using a load includes a main switch connecting a power source and the load in series; a resistor connected in parallel with the main switch between the power source and the load; a bypass switch connected in series with the resistor between the power source and the load and connected in parallel with the main switch; and a control unit that selectively controls the main switch and the bypass switch.

Description

Apparatus for after-treatment of exhaust gas}

The present invention relates to an exhaust gas after-treatment device, and more specifically, to an exhaust gas after-treatment device that treats exhaust gas generated from an internal combustion engine of a vehicle.

When starting a vehicle immediately after it is stopped, a large amount of exhaust gas is emitted from the vehicle's internal combustion engine. These exhaust gases contain harmful components. Exhaust gas after-treatment devices are installed in vehicles to remove harmful components from exhaust gas. The exhaust gas after-processing device supplies current to the load for a certain period of time according to the signal received from the vehicle's control device, raising the load to a high temperature of about 400 degrees or more. After the vehicle is started, when the exhaust gas is emitted from the internal combustion engine, it is burned. Prevents harmful components from being released into the air.

Generally, when voltage is applied to an electrical and electronic system, an inrush current occurs. Inrush current is a transient phenomenon that occurs additionally depending on the size of the load when voltage is applied and causes permanent damage, failure, or abnormal operation of the system. Exhaust gas after-treatment devices are also a type of electrical and electronic system, and when voltage is applied to a load, an inrush current is also generated.

Exhaust gas aftertreatment devices use switches to selectively control the load. That is, a switch is connected between the power source and the load and the switch is controlled on/off to control the voltage supply to the load. The above inrush current momentarily stresses the switch and load of the exhaust gas aftertreatment device, and the switch and load are damaged in the long term due to the stress. Therefore, a method is needed to reduce stress on switches and loads caused by inrush current.

The present invention was proposed to solve the above-mentioned problems, and its purpose is to provide an exhaust gas after-treatment device that can reduce stress caused by inrush current of a switch and load connected to a power source.

According to one aspect, an exhaust gas post-treatment device for post-processing exhaust gas using a load includes a main switch connecting a power source and the load in series; a resistor connected in parallel with the main switch between the power source and the load; a bypass switch connected in series with the resistor between the power source and the load and connected in parallel with the main switch; and a control unit that selectively controls the main switch and the bypass switch.

The control unit may perform a control operation of first turning on the bypass switch, turning on the main switch after a predetermined time, and turning off the bypass switch.

There are multiple pairs of the load and the main switch, each pair is connected in parallel, there are multiple pairs of the resistor unit and the bypass switch, each pair is connected in parallel to each main switch, and the control unit is connected to each load. The main switch and bypass switch connected to each load can be selectively controlled.

The control unit may perform a control operation of, for each load, first turning on the bypass switch connected to the load, turning on the main switch connected to the load after a predetermined time, and turning off the bypass switch connected to the load.

The control unit may perform the control operation for each load with a time difference between each load.

There are multiple pairs of the load and the main switch, each pair is connected in parallel, the resistor unit is commonly connected in parallel to the main switches, and the bypass switch is plural, each pair connected in series to the resistor unit, and each pair is connected in parallel to the main switch. It is connected in parallel to the switch, and the control unit can selectively control the main switch and bypass switch connected to each load for each load.

The control unit may perform a control operation of, for each load, first turning on the bypass switch connected to the load, turning on the main switch connected to the load after a predetermined time, and turning off the bypass switch connected to the load.

The control unit may perform the control operation for each load with a time difference between each load.

According to the present invention, when the exhaust gas after-treatment device is initially started, current flows through a resistor connected in parallel to the main switch, and after a predetermined time, current flows to the main switch, thereby preventing inrush current from flowing to the load. , so that a stabilized current flows. Therefore, damage to components and shortened lifespan can be improved by reducing stress caused by inrush current of the main switch and load.

Figure 1 is a diagram showing the configuration of an exhaust gas post-treatment device according to an embodiment of the present invention.
Figure 2 is a diagram showing the configuration of an exhaust gas post-treatment device according to another embodiment of the present invention.
Figure 3 is a diagram showing the configuration of an exhaust gas post-treatment device according to another embodiment of the present invention.
FIG. 4 is a timing diagram of one embodiment of the exhaust gas after-treatment device of FIG. 1.
FIG. 5 is a timing diagram of one embodiment of the exhaust gas after-treatment device of FIG. 3.

Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the attached drawings. However, identical or similar components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted. The suffix "part" for the components used in the following description is given or used interchangeably only considering the ease of preparing the specification, and does not have a distinct meaning or role in itself. Additionally, in describing the embodiments disclosed in this specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed descriptions will be omitted. In addition, the attached drawings are only for easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited by the attached drawings, and all changes included in the spirit and technical scope of the present invention are not limited. , should be understood to include equivalents or substitutes.

Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

In implementing the present invention, the components may be subdivided for convenience of explanation, but these components may be implemented in one device or module, or one component may be divided into multiple devices or modules. It can also be implemented.

Figure 1 is a diagram showing the configuration of an exhaust gas post-treatment device according to an embodiment of the present invention. Referring to FIG. 1, the exhaust gas after-treatment device according to this embodiment includes a power source 110, a load 120, a main switch 130, a resistance unit 140, a bypass switch 150, and a control unit 160. Includes.

The power source 110 supplies voltage to components of the exhaust gas aftertreatment device, including the load 120. The power source 110 is, for example, a battery of 48V to 400V or more for MHEV or PHEV vehicles, and may be a general lead acid battery. In Figure 1, the INPUT (+) terminal is the positive terminal of the power supply 110, and the INPUT (GND) terminal is the negative terminal.

The load 120 is heated to a high temperature of about 400 degrees or more according to the current supplied from the power source 110 and is a means of burning exhaust gas. For example, load 120 may be a resistor.

The main switch 130 is a switch that connects the power source 110 and the load 120 in series. The main switch 130 is, for example, a Field Effect Transistor (FET). When a switching signal (e.g., 12V) is supplied to the gate of the main switch 130, a voltage difference between the gate-drain and gate-source occurs, causing the current supplied from the power source 110 to flow to the load 120.

More specifically, due to the characteristics of the FET, if the voltage between the gate and drain and the voltage between the gate and source are the same, no current flows. Therefore, when a 12V voltage is provided to the gate of the FET to create a difference between the gate-drain voltage and the gate-source voltage, the gate-drain voltage is 48V, but the gate-source voltage is 60V, which means that the gate-drain and A gate-source voltage difference occurs, causing current to flow to the load 120.

The resistor unit 140 is connected in parallel with the main switch 130 between the power source 112 and the load 120. The bypass switch 150 is connected in series with the resistance unit 140 between the power source 120 and the load 120 and in parallel with the main switch 130. That is, a pair of the resistor unit 140 and the bypass switch 150 connected in series are connected in parallel to the main switch 130.

The bypass switch 150 is, for example, a Field Effect Transistor (FET). When a switching signal (e.g., 12V) is supplied to the gate of the bypass switch 150, a voltage difference between the gate-drain and gate-source occurs, causing the current supplied from the power source 110 to flow into the resistor unit 140. do.

The control unit 160 selectively controls the main switch 130 and the bypass switch 150. The control unit 160 may perform CAN (Controller Area Network) communication with the vehicle's ECU (Electronic Control Unit) and receive an on/off control signal of the exhaust gas after-treatment device from the vehicle's ECU.

When receiving a control signal from the ECU, the control unit 160 first supplies a switching signal (eg, 12V voltage) to the gate of the bypass switch 150 to turn on the bypass switch 150. Therefore, the current supplied from the power source 110 flows through the path of the bypass switch 150 and the resistance unit 140, that is, the bypass path, rather than the path of the main switch 130, thereby increasing the resistance of the resistance unit 140. It decreases in proportion to the value and flows to the load (120). At this time, the voltage (V _load ) applied to the load 120 and the current (I _load ) supplied to the load 120 are as follows (Equation 1). Here, the resistance of the bypass switch 150 is so small that it is ignored.

(Equation 1)

I _load = V _in /(R _{resistance part} + R _load )

V _load = V _in ×R _load / (R _resistance + R _load )

After turning on the bypass switch 150 and a predetermined time has elapsed, the control unit 160 supplies a switching signal (e.g., 12V voltage) to the gate of the main switch 130 to turn on the main switch 130. A control operation is performed to turn off the bypass switch 150. The resistance value of the main switch 130 is very small, so most of the stabilized current flows to the load 120 via the main switch 130. At this time, the voltage (V _load ) applied to the load 120 and the current (I _load ) supplied to the load 120 are as follows (Equation 2). Here, the resistance of the main switch 130 is so small that it is ignored.

(Equation 2)

I _load = V _in /R _load

V _load = V _in

Through selective control of the control unit 160 with respect to the main switch 130 and the bypass switch 150, the inrush current is guided to the bypass path including the resistor 140 during the initial operation of the exhaust gas after-treatment device. By blocking the inrush current from flowing into the load 120 and allowing a stabilized current to flow to the main switch 130 after a predetermined time, the stress caused by the inrush current of the main switch 130 and the load 120 is reduced. It can be reduced.

In the embodiment referring to FIG. 1, there is only one load 120. As another example, multiple loads may be installed in the exhaust gas aftertreatment device. This will be explained with reference to FIG. 2.

Figure 2 is a diagram showing the configuration of an exhaust gas post-treatment device according to another embodiment of the present invention. The exhaust gas post-treatment device according to the present embodiment with reference to FIG. 2 includes a power source 110, a plurality of loads 120-1,..., 120-n, a plurality of main switches 130-1,... , 130-n), a plurality of resistance units (140-1,..., 140-n), a plurality of bypass switches (150-1,..., 150-n), and a control unit 160.

The power source 110 supplies voltage to components of the exhaust gas aftertreatment device, including the load 120. The power source 110 is, for example, a 12V vehicle battery, and may be a general lead acid battery. In Figure 1, the INPUT (+) terminal is the positive terminal of the power supply 110, and the INPUT (GND) terminal is the negative terminal.

Each of the plurality of loads 120-1,..., 120-n is heated to a high temperature of about 400 degrees or more according to the current supplied from the power source 110 and is a means of burning exhaust gas. For example, each load 120-1,..., 120-n may be a resistor.

Each of the plurality of main switches 130-1,..., 130-n is a switch that connects the power source 110 and each load 120-1,..., 120-n in series. That is, the first main switch 130-1 connects the power source 110 and the first load 120-1 in series, and the second main switch 130-2 connects the power source 110 and the second load 120. -2) is connected in series, and the nth main switch (130-n) connects the power source 110 and the nth load (120-n) in series.

Each main switch (130-1,..., 130-n) is, for example, a Field Effect Transistor (FET). When a switching signal (e.g., 12V) is supplied to the gate of each main switch (130-1,..., 130-n), a voltage difference between gate-drain and gate-source occurs, and each main switch (130-n) 1,..., 130-n) causes the current supplied from the power source 110 to flow to the serially connected loads 120-1,..., 120-n.

More specifically, due to the characteristics of the FET, if the voltage between the gate and drain and the voltage between the gate and source are the same, no current flows. Therefore, when a 12V voltage is provided to the gate of the FET to create a difference between the gate-drain voltage and the gate-source voltage, the gate-drain voltage is 48V, but the gate-source voltage is 60V, which means that the gate-drain and A gate-source voltage difference occurs, causing current to flow to the loads (120-1,..., 120-n).

Meanwhile, each main switch (130-1,..., 130-n) includes a resistor unit (140-1,..., 140-n) and a bypass switch (150-1,..., 150) connected in series. -n) pairs are connected in parallel. For example, the first resistance unit 140-1 and the first bypass switch 150-1 are connected in parallel to the first main switch 130-1, and the second main switch 130-2 is connected in parallel. The second resistance unit (140-2) and the second bypass switch (150-2) are connected in parallel, and the nth main switch (130-n) includes the nth resistance unit (140-n) and the nth bypass switch (150). -n) are connected in parallel.

Each bypass switch 150-1,..., 150-n is, for example, a Field Effect Transistor (FET). When a switching signal (e.g., 12V) is supplied to the gate of each bypass switch (150-1,..., 150-n), a voltage difference between gate-drain and gate-source occurs, and the power supply 110 The supplied current flows to each resistance part (140-1,..., 140-n) connected in series.

The control unit 160 selectively controls a plurality of main switches 130-1,..., 130-n and a plurality of bypass switches 150-1,..., 150-n. The control unit 160 performs CAN (Controller Area Network) communication with the vehicle's ECU, and transmits on/off information for each load (120-1,..., 120-n) of the exhaust gas post-processing device from the vehicle's ECU. /off control signal can be received.

When receiving the on control signal for the first load 120-1 from the ECU, the control unit 160 first supplies a switching signal (e.g., 12V voltage) to the gate of the first bypass switch 150-1 to turn the first load 120-1 on. Turn on the bypass switch (150-1). Therefore, the current supplied from the power source 110 is not the path of the first main switch 130-1, but the path of the first bypass switch 150-1 and the first resistance unit 140-1, that is, the bypass path. flows in a path After a predetermined time has elapsed, the control unit 160 supplies a switching signal (e.g., 12V voltage) to the gate of the first main switch 130-1 to turn on the first main switch 130-1 and perform the first bypass. A control operation is performed to turn off the switch 150-1. In the same manner, the control unit 160 controls the remaining loads 120-2,..., 120-n with a time difference between each load.

Through selective control of the control unit 160 for a plurality of main switches (130-1,..., 130-n) and a plurality of bypass switches (150-1,..., 150-n), exhaust gas During the initial operation of the post-processing device, the inrush current is induced into the resistance units (140-1,..., 140-n) to prevent the inrush current from flowing into each load (120-1,..., 120-n). By blocking and allowing a stabilized current to flow to each main switch (130-1,..., 130-n) after a predetermined time, the main switches (130-1,..., 130-n) and the load ( Stress caused by inrush current (120-1,..., 120-n) can be reduced.

In the embodiment referred to in FIG. 2, resistor units 140-1,..., 140-n are connected in parallel to each main switch 130-1,..., 130-n to block inrush current. In order to block the inrush current, each resistance unit (140-1,..., 140-n) uses a very large capacity resistor. Therefore, as the load (120-1,..., 120-n) increases in the exhaust gas after-treatment device, a proportionally larger number of resistance units (140-1,..., 140-n) must be installed. Therefore, it costs a lot and takes up a lot of space. When a plurality of main switches 130-1,..., 130-n commonly use one resistance unit, these cost and space problems can be solved.

Figure 3 is a diagram showing the configuration of an exhaust gas after-treatment device according to another embodiment of the present invention. The exhaust gas post-treatment device according to the present embodiment referring to FIG. 3 includes a power source 110, a plurality of loads 120-1,..., 120-n, a plurality of main switches 130-1,... , 130-n), one resistance unit 140, a plurality of bypass switches 150-1,..., 150-n), and a control unit 160.

In the embodiment shown in FIG. 3 , compared to the embodiment shown in FIG. 2 , one resistor unit 140 is commonly connected in parallel to each of the plurality of main switches 130-1,..., 130-n. And each of the plurality of bypass switches (150-1,..., 150-n) is connected in series to the one resistor unit 140 and is connected in parallel to each main switch (130-1,..., 130-n). connected.

The control unit 160 selectively controls a plurality of main switches 130-1,..., 130-n and a plurality of bypass switches 150-1,..., 150-n to control each load ( 120-1,..., 120-n) to block inrush current from flowing. The control unit 160 performs CAN (Controller Area Network) communication with the vehicle's ECU, and transmits on/off signals for each load (120-1,..., 120-n) of the exhaust gas post-processing device from the vehicle's ECU. An off control signal can be received.

When receiving the on control signal for the first load 120-1 from the ECU, the control unit 160 first supplies a switching signal (e.g., 12V voltage) to the gate of the first bypass switch 150-1 to turn the first load 120-1 on. Turn on the bypass switch (150-1). Accordingly, the current supplied from the power source 110 flows not through the path of the first main switch 130-1, but through the path of the first bypass switch 150-1 and the resistor unit 140, that is, through the bypass path. At this time, the voltage applied to the first load (120-1) (V _{load_first load} ) and the current (I _{load_first load} ) supplied to the first load (120-1) are as follows (Equation 3) same. Here, the resistance of the first bypass switch 150-1 is so small that it is ignored.

(Equation 3)

I _{load_1st load} = V _in /(R _{resistance part} + R _{1st load} )

V _{load_1st load} = V _in ×R _{1st load} / (R _{resistance part} + R _{1st load} )

After a predetermined time has elapsed, the control unit 160 supplies a switching signal (e.g., 12V voltage) to the gate of the first main switch 130-1 to turn on the first main switch 130-1 and perform the first bypass. A control operation is performed to turn off the switch 150-1. At this time, the voltage applied to the first load (120-1) (V _{load_first load} ) and the current (I _{load_first load} ) supplied to the first load (120-1) are as follows (Equation 2) same. Here, the resistance of the first main switch 130-1 is so small that it is ignored.

(Equation 2)

I _{load_1st load} = V _in /R _{1st load}

V _{load_first load} = V _in

In the same manner, the control unit 160 controls the remaining loads 120-2,..., 120-n with a time difference between each load.

Through selective control of the control unit 160 for a plurality of main switches (130-1,..., 130-n) and a plurality of bypass switches (150-1,..., 150-n), exhaust gas During the initial operation of the post-processing device, the inrush current is induced into one common resistance unit 140 to block the inrush current from flowing into each load (120-1,..., 120-n), and after a predetermined time has elapsed By allowing a stabilized current to flow through each main switch (130-1,..., 130-n), the main switches (130-1,..., 130-n) and the loads (120-1,...) , 120-n) stress caused by inrush current can be reduced.

FIG. 4 is a timing diagram of one embodiment of the exhaust gas after-treatment device of FIG. 1. Referring to FIG. 4, when receiving the High signal, which is a control signal from the ECU, the control unit 160 first supplies a switching signal (e.g., 12V voltage) to the gate of the bypass switch 150 to turn on the bypass switch 150. I order it. Therefore, the current supplied from the power source 110 flows through the path of the bypass switch 150 and the resistance unit 140, that is, the bypass path, rather than the path of the main switch 130, and is proportional to the resistance value of the resistance unit 140. It decreases and flows to the load (120).

And after time t1 has elapsed, the control unit 160 turns on the main switch 130 by supplying a switching signal (eg, 12V voltage) to the gate of the main switch 130. After turning on the main switch 130, the current flowing through the main switch 130 and the load 120 increases for t2 time, and when t2 time elapses, the maximum available current flows through the main switch 130 and the load 120. .

After t3 time has elapsed, the control unit 160 turns off the bypass switch 150. Accordingly, the current flowing through the bypass switch 150 decreases. And when receiving a Low signal from the ECU, the control unit 160 turns off the main switch 130. Accordingly, the current flowing through the main switch 130 and the load 120 gradually decreases and turns off.

The timing diagram described above with reference to FIG. 4 is the same for each load 120-1,..., 120-n of the exhaust gas after-treatment device described with reference to FIG. 2. A bypass switch (150-1,..., 150-n) and a resistance unit (140-1,..., 140-n) are provided for each load (120-1,..., 120-n). Because. However, the exhaust gas after-treatment device described with reference to FIG. 3 is different because one resistance unit 140 is commonly connected in parallel to a plurality of loads 120-1,..., 120-n. That is, the exhaust gas after-treatment device described with reference to FIG. 3 does not turn on each bypass switch (150-1,..., 150-n) at the same time.

FIG. 5 is a timing diagram of one embodiment of the exhaust gas after-treatment device of FIG. 3. Referring to FIG. 5, when receiving the High signal (signal 1 in FIG. 5), which is an on control signal for turning on the first load 120-1 from the ECU, the control unit 160 first turns on the first bypass switch 150-1. A switching signal (e.g., 12V voltage) is supplied to the gate of 1) to turn on the first bypass switch 150-1. Therefore, the current supplied from the power source 110 flows through the path of the first bypass switch 150-1 and the resistance unit 140, that is, the bypass path, rather than the path of the first main switch 130-1, and flows through the resistance unit ( It decreases in proportion to the resistance value of 140) and flows to the first load (120-1).

And after time t1 has elapsed, the control unit 160 supplies a switching signal (e.g., 12V voltage) to the gate of the first main switch 130-1 to turn on the first main switch 130-1. Turn it on. After turning on the first main switch (130-1), the current flowing through the first main switch (130-1) and the first load (120-1) increases for t2 time, and when t2 time elapses, the first main switch ( The maximum available current flows through 130-1) and the first load 120-1.

After t3 time has elapsed, the control unit 160 turns off the first bypass switch 150-1. Accordingly, the current flowing through the first bypass switch 150-1 decreases. And when receiving a Low signal from the ECU, the control unit 160 turns off the first main switch 130-1. Accordingly, the current flowing through the first main switch 130-1 and the first load 120-1 gradually decreases and turns off.

Meanwhile, during time t3, the control unit 160 may receive a High signal (signal n in FIG. 5), which is an on control signal for turning on the nth load 120-n, from the ECU. In this case, the control unit 160 does not immediately turn on the n-th bypass switch 150-n, but at the point when the current flowing through the first bypass switch 150-1 becomes zero, the n-th bypass switch (150-n) A switching signal (e.g., 12V voltage) is supplied to the gate of 150-n to turn on the nth bypass switch 150-n. Therefore, the current supplied from the power source 110 flows not through the path of the n-th main switch 130-n, but through the path of the n-th bypass switch 150-n and the resistance unit 140, that is, the bypass path, and flows through the resistance unit ( It decreases in proportion to the resistance value of 140) and flows to the nth load (120-n).

And after time t4 has elapsed, the control unit 160 supplies a switching signal (e.g., 12V voltage) to the gate of the nth main switch 130-n to turn on the nth main switch 130-n. Turn it on. After turning on the n-th main switch (130-n), the current flowing through the n-th main switch (130-n) and the n-th load (120-n) increases for t5 time, and when t5 time elapses, the n-th main switch ( 130-n) and the first load (120-n), the maximum available current flows.

After t6 time has elapsed, the control unit 160 turns off the nth bypass switch 150-n. Accordingly, the current flowing to the nth bypass switch 150-n decreases. And when receiving a Low signal from the ECU, the control unit 160 turns off the nth main switch (130-n). Accordingly, the current flowing through the n-th main switch (130-n) and the n-th load (120-n) gradually decreases and turns off.

As described with reference to FIG. 5, the control unit 160 does not turn on two or more bypass switches 150-1,..., 150-n at the same time. When two or more bypass switches 150-1,..., 150-n are turned on at the same time, a large voltage is applied to the commonly used resistor 140, which may damage the resistor 140. Therefore, as described with reference to FIG. 5, the control unit 160 does not turn on two or more bypass switches 150-1,..., 150-n at the same time, but turns on the bypass switches 150-1, When the current flowing through (..., 150-n) becomes zero, it is controlled by turning on the next bypass switch (150-1,..., 150-n) at the same time or after a certain period of time.

While this specification includes many features, such features should not be construed as limiting the scope of the invention or the scope of the claims. Additionally, features described in individual embodiments herein may be combined and implemented in a single embodiment. Conversely, various features described in a single embodiment herein may be implemented individually or in combination as appropriate in various embodiments.

The present invention described above is capable of various substitutions, modifications and changes without departing from the technical spirit of the present invention to those of ordinary skill in the technical field to which the present invention pertains. It is not limited by the drawings.

110: power
120: load
130: main switch
140: resistance
150: bypass switch
160: control unit

Claims (8)

In the exhaust gas post-treatment device that post-processes exhaust gas using a load,
a main switch connecting the power source and the load in series;
a resistor connected in parallel with the main switch between the power source and the load;
a bypass switch connected in series with the resistor between the power source and the load and connected in parallel with the main switch; and
An exhaust gas after-treatment device including a control unit that selectively controls the main switch and the bypass switch. According to paragraph 1,
The control unit,
An exhaust gas after-treatment device, characterized in that it performs a control operation of first turning on the bypass switch, turning on the main switch after a predetermined time, and turning off the bypass switch. According to paragraph 1,
There are a plurality of pairs of the load and the main switch, and each pair is connected in parallel,
There are a plurality of pairs of the resistor unit and the bypass switch, and each pair is connected in parallel to each main switch,
The control unit,
An exhaust gas after-treatment device characterized by selectively controlling the main switch and bypass switch connected to each load for each load. According to paragraph 3,
The control unit,
For each load, a control operation is performed to first turn on the bypass switch connected to the load, turn on the main switch connected to the load after a predetermined time, and turn off the bypass switch connected to the load. processing unit. According to paragraph 4,
The control unit,
An exhaust gas post-treatment device characterized in that the control operation is performed for each load with a time difference between each load. According to paragraph 1,
There are a plurality of pairs of the load and the main switch, and each pair is connected in parallel,
The resistor unit is commonly connected in parallel to the main switches,
The bypass switches are plural, each connected in series to the resistor and connected in parallel to each main switch,
The control unit,
An exhaust gas after-treatment device characterized by selectively controlling the main switch and bypass switch connected to each load for each load. According to clause 6,
The control unit,
For each load, a control operation is performed to first turn on the bypass switch connected to the load, turn on the main switch connected to the load after a predetermined time, and turn off the bypass switch connected to the load. processing unit. In clause 7,
The control unit,
An exhaust gas post-treatment device characterized in that the control operation is performed for each load with a time difference between each load.