Exhaust gas aftertreatment device

Abstract

An exhaust gas aftertreatment device capable of controlling at least two or more switches in one control unit and monitoring the state of components is disclosed. The exhaust gas aftertreatment device according to one aspect of the present invention includes a switching unit including at least two switches and supplying a current from a first power source to a resistor unit, a switching signal supply unit supplying a switching signal to the switching unit to selectively control an operation of the switching unit, a switching power supply unit supplying a second power source to the switching signal supply unit, a control unit controlling the on / off of the switching signal supply unit, and an interface unit activating the control unit in response to a control signal received from a master control unit.

Description

[Technical Field]

[0001] The present invention relates to an exhaust gas aftertreatment device, and more particularly to an exhaust gas aftertreatment device that treats exhaust gas generated in an internal combustion engine of a vehicle.

[0002] This application claims priority based on Korean Patent Application No. 10-2021-0136170, filed on October 13, 2021, and the entire contents disclosed in the specification and drawings of that application are incorporated herein by reference. [Background technology]

[0003] When a vehicle's engine is started immediately after being stopped, a large amount of exhaust gas is emitted from the vehicle's internal combustion engine. This exhaust gas contains harmful components. To remove the harmful components from the exhaust gas, an exhaust gas aftertreatment device is installed in the vehicle. The exhaust gas aftertreatment device supplies current to a resistor for a certain period of time in response to a signal received from the vehicle's control device, raising the resistor to a high temperature of approximately 400°C or more. When the engine is started and exhaust gas is emitted from the internal combustion engine, Burning the exhaust gas This prevents harmful substances from being released into the atmosphere.

[0004] A typical example of an exhaust gas aftertreatment device is Patent Document 1. However, the exhaust gas aftertreatment device in Patent Document 1 has a structure in which a control unit is connected to each of a plurality of switches in order to transmit an external voltage to a resistor. In other words, the number of control units increases as the number of switches increases. As a result, it is not possible to monitor various conditions in an integrated manner, which increases costs and raises safety concerns. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Korean Patent Publication No. 10-2021-0018496 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above problems, and aims to provide an exhaust gas aftertreatment device in which one control unit controls at least two or more switches and the state of the constituent elements can be monitored. [Means for solving the problem]

[0007] An exhaust gas aftertreatment device according to one aspect of the present invention includes a switching unit including at least two switches and supplying current from a first power source to a resistor unit, a switching signal supply unit supplying a switching signal to the switching unit to selectively control the operation of the switching unit, a switching power supply unit supplying a second power source to the switching signal supply unit, a control unit controlling the on / off of the switching signal supply unit, and an interface unit activating the control unit in response to a control signal received from a master control unit.

[0008] The exhaust gas aftertreatment device may further include a temperature monitoring unit that monitors the temperature of the switching unit, and the control unit may control the on / off of the switching signal supply unit based on information received from the temperature monitoring unit.

[0009] The temperature monitoring unit may be a negative temperature coefficient thermistor, and the control unit may control the on / off of the switching signal supply unit based on a voltage according to a resistance value of the negative temperature coefficient thermistor.

[0010] The exhaust gas aftertreatment device may further include a first current sensor located between the switching unit and the resistor unit to detect a current value, and a current monitoring unit that transmits an off signal to the switching signal supply unit when the current value is equal to or greater than a reference value.

[0011] The current monitoring unit transmits an off signal to the control unit, and the control unit asks the master control unit whether to turn the switching unit on or off in response to the off signal received from the current monitoring unit, and when receiving an on signal from the master control unit, transmits an on signal to the switching signal supply unit.

[0012] The exhaust gas aftertreatment device may further include a second current sensor provided on a ground side corresponding to the first power source and configured to detect a current value, and the control unit may transmit an off signal to the switching signal supply unit when the current value detected by the second current sensor does not match the current value detected by the first current sensor.

[0013] The exhaust gas aftertreatment device further includes an input voltage monitoring unit that monitors the voltage values ​​of the first power source and the second power source and transmits the voltage values ​​to the control unit, and the control unit may transmit an off signal to the switching signal supply unit if the voltage values ​​fall outside a reference range.

[0014] The exhaust gas aftertreatment device further includes an output voltage monitoring unit that monitors the voltage input to the resistor unit and the voltage output from the resistor unit and transmits the voltage to the control unit, and the control unit may transmit an off signal to the switching signal supply unit if the voltage value monitored by the output voltage monitoring unit falls outside a reference range.

[0015] The interface unit may adjust the voltage of the second power supply to a lower voltage and supply the lower voltage to the control unit, thereby activating the control unit. [Effects of the Invention]

[0016] The exhaust gas aftertreatment device according to the present invention controls a switching unit consisting of at least two switches with one control unit, and can monitor various conditions in an integrated manner with an input voltage monitoring unit, a temperature monitoring unit, a current monitoring unit, and an output voltage monitoring unit, thereby enabling cost savings and stable control. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram showing a configuration of an exhaust gas aftertreatment device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, regardless of the drawing number, identical or similar elements will be given the same reference numerals, and redundant description thereof will be omitted. The suffix "(part)" used in the following description of elements is added or used interchangeably solely for ease of description and does not have any distinguishing meaning or function. Furthermore, in describing the embodiments disclosed herein, if a detailed description of related prior art is deemed to unnecessarily obscure the gist of the embodiments disclosed herein, such a detailed description will be omitted. Furthermore, the accompanying drawings are intended to facilitate understanding of the embodiments disclosed herein, and it should be understood that the accompanying drawings do not limit the technical concept disclosed herein, and all modifications, equivalents, or alternatives within the concept and technical scope of the present invention are encompassed.

[0019] The singular includes the plural unless the context clearly dictates otherwise. Furthermore, in this specification, the terms "comprise" or "have" are intended to specify the presence of a stated feature, number, step, operation, component, part, or combination thereof, but do not exclude the possible presence or addition of one or more other features, number, step, operation, component, part, or combination thereof.

[0020] In implementing the present invention, for the convenience of explanation, the components may be divided and described, but these components may be implemented within a single device or module, or one component may be divided and implemented across multiple devices or modules.

[0021] 1 is a diagram showing the configuration of an exhaust gas aftertreatment device according to an embodiment of the present invention. Referring to FIG. 1, the exhaust gas aftertreatment device according to this embodiment includes an interface unit 101, a power switch 102, a control unit 103, an input voltage monitoring unit 104, a temperature monitoring unit 105, a switching power supply unit 106, a switching signal supply unit 107, a current monitoring unit 108, an output voltage monitoring unit 109, a switching unit 110, current sensors 111 and 112, and a resistor unit 113.

[0022] The interface unit 101 performs CAN (Controller Area Network) communication with the vehicle's master control unit via CAN terminals (CAN high H / low L), transmits CAN signals (e.g., on / off signals of the resistor unit 113) received from the master control unit to the control unit 103 (RxD), and transmits response signals TxD received from the control unit 103 to the master control unit. The interface unit 101 also receives power from a 12V second power supply KL30 and supplies voltage to components for operating the exhaust gas aftertreatment device, including the control unit 103. In FIG. 1, the KL31 GND terminal is the ground of the second power supply KL30. Here, the second power supply KL30 is a 12V battery of a mild hybrid vehicle, which may be a typical lead-acid battery, and supplies voltage to the vehicle's general electrical loads.

[0023] The interface unit 101 controls the supply of 12V power to components requiring 12V power using a power switch 102. That is, the components requiring 12V power are directly connected to the second power supply KL30 via the power switch 102 to receive power, and the interface unit 101 controls the supply of 12V power by turning on and off the power switch 102. For components requiring 5V power, the interface unit 101 adjusts the 12V voltage to 5V using a regulator and supplies the 5V power.

[0024] In one embodiment, when the interface unit 101 receives an on / off control signal from the master control unit via CAN communication, it controls the on / off of the power (5V, 12V) supplied to the components to turn on / off the entire exhaust gas aftertreatment device. For example, when the interface unit 101 receives a sleep mode control signal from the master control unit, it turns off the 5V voltage to keep the exhaust gas aftertreatment device in a sleep state. That is, it cuts off the supply of 5V power to all the components including the power switch 102. When the interface unit 101 receives a wake-up control signal from the master control unit, it turns on the 5V voltage to activate the entire exhaust gas aftertreatment device including the power switch 102.

[0025] In addition, the interface unit 101 transmits and receives status information to and from the control unit 103 through a serial interface (e.g., SPI (serial peripheral interface)) and performs a watchdog function to monitor the status of the control unit 103. The interface unit 101 monitors the status of the control unit 103 using the watchdog function, determines whether or not the control unit 103 is malfunctioning, and resets the control unit 103, or transmits the status information to the master control unit through CAN communication.

[0026] Preferably, the interface unit 101 can be implemented in the form of a system basis chip (SBC).

[0027] The control unit 103 is activated by receiving 5V power from the interface unit 101, and controls the switching unit 110 via the switching power supply unit 106 and the switching signal supply unit 107. Specifically, the control unit 103 transmits a control signal (e.g., a pulse width modulation (PWM) signal) to the switching power supply unit 106, causing the switching power supply unit 106 to supply the 12V power supplied from the second power supply KL30 to the switching signal supply unit 107. As a result, the switching signal supply unit 107 supplies the 12V power as a switching signal to the switching unit 110. The switching signal supply unit 107 may be a gate driver.

[0028] The control unit 103 may control the switching unit 110 using information received from the temperature monitoring unit 105, which monitors the temperature of the switching unit 110. When the temperature of the switching unit 110 exceeds a certain temperature, the control unit 103 may warn the driver or transmit an off signal to the switching signal supplying unit 107 to turn off the switching unit 110. When the temperature drops below the certain temperature, the control unit 103 may transmit an on signal to the switching signal supplying unit 107 to turn on the switching unit 110 again. For example, the control unit 103 may warn the driver when the temperature reaches 130°C, transmit an off signal to the switching signal supplying unit 107 to turn off the switching unit 110 when the temperature exceeds 145°C, and then transmit an on signal to the switching signal supplying unit 107 to turn on the switching unit 110 again when the temperature drops below 130°C. In other words, the control unit 103 may prevent the switching unit 110 from rising above a certain temperature.

[0029] In one embodiment, the temperature monitoring unit 105 may be a negative temperature coefficient (NTC) thermistor. A negative temperature coefficient thermistor has a characteristic that its resistance decreases as the temperature increases. When the temperature of the switching unit 110 exceeds a certain temperature, the resistance of the temperature monitoring unit 105 decreases, and an ADC (Analog-Digital Converter) voltage applied to the control unit 103 increases. As a result, the control unit 103 can measure the temperature of the switching unit 110 using the voltage received from the temperature monitoring unit 105.

[0030] The switching unit 110 is turned on by a switching signal received from the switching signal supply unit 107 and supplies current from the 48V first power supply KL40 to the resistor unit 113. Here, the first power supply KL40 is a 48V battery of a mild hybrid vehicle and is used to drive a motor generator of the vehicle. Preferably, the switching unit 110 is composed of at least two switches, for example, field effect transistors (FETs). The reason for comprising at least two switches is to prepare for the case where one switch is shorted. For example, if the switching unit 110 is composed of one switch, if the switch is shorted, a large amount of current flowing into the switch may flow to the resistor unit 113, causing a breakdown of the resistor unit 113. If the switching unit 110 is composed of two or more switches, even if one switch is shorted, the other switches may be controlled to be on or off to prevent a large amount of current from flowing to the resistor unit 113.

[0031] When the switch constituting the switching unit 110 is an FET, a 12V voltage is supplied as a switching signal from the switching signal supply unit 107 to the gate of the FET. Due to the characteristics of an FET, if the gate-drain voltage and the gate-source voltage are the same, no current flows. Therefore, when a 12V voltage is supplied 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. This creates a voltage difference between the gate-drain and gate-source, and current may flow to the resistor unit 113.

[0032] In addition, the control unit 103 may control the switching unit 110 using information received from the input voltage monitoring unit 104 , the current monitoring unit 108 and the output voltage monitoring unit 109 .

[0033] First, the input voltage monitoring unit 104 detects the voltage values ​​of the second power supply KL30 and the first power supply KL40, which are input power sources, and transmits the detected voltage values ​​to the control unit 103. If the voltage value of the second power supply KL30 or the first power supply KL0 is outside the reference range, the control unit 103 transmits an OFF signal to the switching signal supplying unit 107 to turn off the switching unit 110. At this time, the control unit 103 transmits status information of the switching unit 110 to the master control unit using CAN communication and asks whether to maintain the switching unit 110 in the OFF state or switch it to the ON state. If the control unit 103 receives an ON signal for the switching unit 110 from the master control unit, it resets the switching signal supplying unit 107 and then transmits an ON signal to the switching signal supplying unit 107 to turn on the switching unit 110.

[0034] The current monitoring unit 108 receives a current value sensed by a current sensor 111 located between the switching unit 110 and the resistor unit 113 and transmits the current value to the control unit 103. If the received current value is equal to or greater than a reference value, the control unit 103 may transmit an off signal to the switching signal supplying unit 107 to turn off the switching unit 110. Alternatively, if the current monitoring unit 108 receives an overcurrent value equal to or greater than the reference value from the current sensor 111, the current monitoring unit 108 transmits an off signal to the switching signal supplying unit 107 to immediately turn off the switching unit 110 without going through the control unit 103, and also transmits an off signal to the control unit 103. As a result, the switching signal supplying unit 107 may cut off power supplied to the switching unit 110 to immediately turn off the switching unit 110.

[0035] At this time, after turning off the switching unit 110 or when the control unit 103 receives an off signal from the current monitoring unit 108 as described above, the control unit 103 transmits state information of the switching unit 110 to the master control unit using CAN communication and asks whether to maintain the state of the switching unit 110 in the off state or switch it to the on state. When the control unit 103 receives an on signal for the switching unit 110 from the master control unit, the control unit 103 resets the switching signal supply unit 107 and then transmits an on signal for the switching unit 110 to the switching signal supply unit 107 to turn on the switching unit 110.

[0036] In addition to the current sensor 111, another current sensor 112 is provided on the side of the ground KL41 corresponding to the first power supply KL40. The current sensor 112 is used to check the normal operation of the loop connecting the first power supply KL40 to the resistor unit 113 and the ground KL41. The control unit 103 receives the current value from the current sensor 112 and checks the normal operation of the current sensor 112. 111 If they do not match (for example, if the ground KL41 is short-circuited), the switching unit 110 is turned off by transmitting an OFF signal to the switching signal supply unit 107.

[0037] Next, the output voltage monitoring unit 109 monitors the voltage input to and output from the resistor unit 113 and transmits the monitored voltage value to the control unit 103. The voltage value input to the resistor unit 113 is the voltage between the positive voltage of the switching unit 110 and the ground KL41 corresponding to the first power supply KL40. The control unit 103 transmits the voltage value input to and output from the resistor unit 113 to the master control unit. Furthermore, if the voltage value input to and output from the resistor unit 113 are outside a reference range, the control unit 103 may transmit an off signal to the switching signal supplying unit 107 to turn off the switching unit 110.

[0038] At this time, the control unit 103 turns off the switching unit 110 and then transmits state information of the switching unit 110 to the master control unit using CAN communication to inquire whether to maintain the state of the switching unit 110 in the off state or to switch it to the on state. When the control unit 103 receives an on signal for the switching unit 110 from the master control unit, it resets the switching signal supply unit 107 and then transmits an on signal to the switching signal supply unit 107 to turn on the switching unit 110.

[0039] The exhaust gas aftertreatment device according to the above embodiment controls the switching unit 110, which is composed of at least two switches, using one control unit 103, and can monitor various states of the exhaust gas aftertreatment device in an integrated manner using the input voltage monitoring unit 104, temperature monitoring unit 105, current monitoring unit 108, and output voltage monitoring unit 109, thereby enabling cost savings and stable control.

[0040] While the present specification includes many features, such features should not be construed as limiting the scope of the present invention or the claims. Also, features described herein as separate embodiments may be implemented in combination in a single embodiment. Conversely, various features described herein as a single embodiment may be implemented in multiple embodiments individually or in any suitable combination.

[0041] The present invention as described above is not limited to the above-described embodiments and the accompanying drawings, since various substitutions, modifications and changes can be made by a person having ordinary skill in the art to which the present invention pertains without departing from the technical spirit of the present invention.

Claims

1. An exhaust gas aftertreatment device, a switching section including at least two switches connected in series and configured to supply current from the first power supply to the resistor section; a switching signal supply unit that supplies a switching signal to the switching unit to selectively control an operation of the switching unit; a switching power supply unit that supplies a second power source to the switching signal supply unit; a control unit that controls the on / off of the switching signal supply unit; an interface unit that activates the control unit in response to a control signal received from a master control unit; a first current sensor located between the switching unit and the resistor unit and configured to sense a current value; a current monitoring unit that transmits an OFF signal to the switching signal supply unit without passing through the control unit and also transmits the OFF signal to the control unit when the current value is equal to or greater than a reference value in order to immediately turn off the switching unit without passing through the control unit, The control unit an exhaust gas aftertreatment device that inquires of the master control unit whether to turn on or off the switching unit in response to an off signal received from the current monitoring unit, and transmits an on signal to the switching signal supply unit when an on signal is received from the master control unit.

2. Further comprising a temperature monitoring unit that monitors the temperature of the switching unit; The control unit The exhaust gas aftertreatment device according to claim 1, wherein the switching signal supply unit is controlled to be turned on or off based on information received from the temperature monitoring unit.

3. the temperature monitoring unit is a negative temperature coefficient thermistor, 3. The exhaust gas aftertreatment device according to claim 2, wherein the control unit controls the on / off of the switching signal supply unit based on a voltage according to a resistance value of the negative temperature coefficient thermistor.

4. a second current sensor disposed on a ground side corresponding to the first power supply and configured to sense a current value; 2. The exhaust gas aftertreatment device according to claim 1, wherein the control unit transmits an off signal to the switching signal supply unit when a current value sensed by the second current sensor does not match a current value sensed by the first current sensor.

5. an input voltage monitoring unit that monitors voltage values ​​of the first power supply and the second power supply and transmits the voltage values ​​to the control unit; The control unit The exhaust gas aftertreatment device according to claim 1, wherein an OFF signal is transmitted to the switching signal supply unit when the voltage value is out of a reference range.

6. The interface unit 2. The exhaust gas aftertreatment device according to claim 1, wherein the voltage of the second power supply is adjusted to a lower voltage and supplied to the control unit, thereby activating the control unit.

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