Exhaust gas aftertreatment device

Abstract

An exhaust gas aftertreatment device is disclosed that controls at least two or more switches in a single control unit and can monitor the state of its constituent elements. [Solution] The exhaust gas aftertreatment device of the present invention includes at least two switches: a switching unit that supplies current from a first power supply to a resistor; a switching signal supply unit that supplies a switching signal to the switching unit to selectively control the operation of the switching unit; a switching power supply unit that supplies a second power supply to the switching signal supply unit; a control unit that controls the on / off state of the switching signal supply unit; and an interface unit that activates 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 by 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 all of the content disclosed in the specification and drawings of the application is incorporated into this application.

Background Art

[0003] When the engine of a parked vehicle is immediately started, a large amount of exhaust gas is discharged from the internal combustion engine of the vehicle. Such exhaust gas contains harmful components. An exhaust gas aftertreatment device is provided in the vehicle to remove the harmful components of the exhaust gas. The exhaust gas aftertreatment device supplies current to a resistance part for a certain period of time in response to a signal received from a control device of the vehicle to heat the resistance part to a temperature of about 400° C or higher, and when the engine is started and exhaust gas is discharged from the internal combustion engine, it burns the exhaust gas to prevent the discharge of harmful components into the atmosphere.

[0004] Patent Document 1 is cited as a representative exhaust gas aftertreatment device. However, the exhaust gas aftertreatment device of Patent Document 1 has a structure in which a control part is connected for each of a plurality of switches to transmit an external voltage to the resistance part. That is, as the number of switches increases, the number of control parts also increases. Therefore, various states cannot be integrally monitored, the cost increases, and furthermore, safety problems occur.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

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

[0007] An exhaust gas aftertreatment device according to one aspect of the present invention includes at least two switches: a switching unit that supplies current from a first power supply to a resistor; a switching signal supply unit that supplies a switching signal to the switching unit to selectively control the operation of the switching unit; a switching power supply unit that supplies a second power supply to the switching signal supply unit; a control unit that controls the on / off state of the switching signal supply unit; and an interface unit that activates the control unit in response to a control signal received from a master control unit.

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

[0009] The temperature monitoring unit is a negative temperature coefficient thermistor, and the control unit can control the on / off state of the switching signal supply unit based on the voltage due to the 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 for sensing 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, in response to the off signal received from the current monitoring unit, asks the master control unit whether to turn the switching unit on or off. Upon receiving an on signal from the master control unit, the control unit can transmit an on signal to the switching signal supply unit.

[0012] The exhaust gas aftertreatment device further includes a second current sensor provided on the ground side corresponding to the first power supply and sensing a current value, and the control unit may transmit an off signal to the switching signal supply unit if the current value sensed by the second current sensor does not match the current value sensed 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 supply and the second power supply and transmits them to the control unit, and the control unit may transmit an off signal to the switching signal supply unit if the voltage value falls 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 and the voltage output from the resistor and transmits this information 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 can activate the control unit by adjusting the voltage of the second power supply to a lower voltage and supplying it to 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 a single control unit, and various conditions can be comprehensively monitored by an input voltage monitoring unit, a temperature monitoring unit, a current monitoring unit, and an output voltage monitoring unit, thereby enabling cost reduction and stable control. [Brief explanation of the drawing]

[0017] [Figure 1] This figure shows the configuration of an exhaust gas aftertreatment device according to one embodiment of the present invention. [Modes for carrying out the invention]

[0018] The embodiments disclosed herein will now be described in detail with reference to the attached drawings. However, regardless of the reference numerals in the drawings, identical or similar components will be assigned the same reference numeral, and redundant descriptions will be omitted. The suffix "part" used in the following description of components is added or mixed in solely for the sake of ease of specification preparation and does not have a meaning or role that distinguishes them from one another. Furthermore, in describing the embodiments disclosed herein, if it is determined that a specific description of related prior art would unnecessarily obscure the gist of the embodiments disclosed herein, such detailed description will be omitted. In addition, the attached drawings are intended to facilitate understanding of the embodiments disclosed herein, and it should be understood that the attached drawings do not limit the technical ideas disclosed herein and may include all modifications, equivalents, or substitutes that fall within the concept and technical scope of the present invention.

[0019] Unless otherwise specified in the context, singular expressions include plural expressions. Furthermore, in this specification, terms such as “includes” or “having” are used to identify the presence of features, figures, stages, operations, components, parts, or combinations thereof described in the specification, and do not preclude the presence or addition of one or more other features, figures, stages, operations, components, parts, or combinations thereof.

[0020] For the sake of explanation, the components of the present invention may be subdivided and described in detail, but these components may be implemented in a single device or module, or a single component may be implemented by dividing it into multiple devices or modules.

[0021] 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 Figure 1, the exhaust gas post-treatment 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, 112, and a resistance unit 113.

[0022] The interface unit 101 performs CAN communication with the master control unit of the vehicle via CAN (Controller Area Network) terminals (CAN high H / low L), transmits the CAN signal (for example, the on / off signal of the resistance unit 113) received from the master control unit to the control unit 103 (RxD), and transmits the response signal TxD received from the control unit 103 to the master control unit. Also, the interface unit 101 receives power from the 12V second power supply KL30 and supplies voltage to the components for operating the exhaust gas post-treatment device including the control unit 103. In Figure 1, the KL31GND terminal is the ground of the second power supply KL30. Here, the second power supply KL30 is the 12V battery of a mild hybrid vehicle, which can be a normal lead-acid battery and supplies voltage to the general electrical load of the vehicle.

[0023] The interface unit 101 controls the supply of 12V power to the components that require 12V power by the power switch 102. That is, the components that require 12V power are directly connected to the second power supply KL30 via the power switch 102 to receive power. At this time, the interface unit 101 controls the on / off of the power switch 102 to control the supply of 12V power. The interface unit 101 adjusts the 12V voltage to 5V by a regulator and supplies it to the components that require 5V power.

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

[0025] Also, 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 can use the watchdog function to monitor the status of the control unit 103, determine whether there is a failure in the control unit 103, reset the control unit 103, or transmit status information to the master control unit through CAN communication.

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

[0027] The control unit 103 is activated by receiving a 5V power supply 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 (for example, a pulse width modulation (PWM) signal) to the switching power supply unit 106 so that the switching power supply unit 106 supplies the 12V power supply 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 supply to the switching unit 110 as a switching signal. The switching signal supply unit 107 may be a gate driver.

[0028] The control unit 103 can 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 can warn the driver or transmit an off signal to the switching signal supply unit 107 to turn off the switching unit 110. When the temperature falls below the certain temperature, it can transmit an on signal to the switching signal supply unit 107 to turn on the switching unit 110. For example, when the temperature reaches 130°, the control unit 103 can warn the driver, and when it reaches 145° or higher, it can transmit an off signal to the switching signal supply unit 107 to turn off the switching unit 110. Later, when the temperature drops below 130°, it can transmit an on signal to the switching signal supply unit 107 to turn on the switching unit 110. In other words, the control unit 103 can prevent the temperature of 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 the characteristic that its resistance decreases as the temperature rises. When the temperature of the switching unit 110 rises above a certain temperature, the resistance of the temperature monitoring unit 105 decreases, causing the ADC (Analog-Digital Converter) voltage applied to the control unit 103 to increase. 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 the 48V battery of the mild hybrid vehicle and is used to drive the vehicle's motor generator. Preferably, the switching unit 110 is composed of at least two switches, and the switches are, for example, FETs (Field Effect Transistors). The reason for being composed of at least two switches is to accommodate the case where one switch shorts out. For example, if the switching unit 110 is composed of one switch, if that switch shorts out, a large amount of current flowing into that switch may flow to the resistor unit 113 and induce a failure of the resistor unit 113. If the switching unit 110 is composed of two or more switches, even if one switch shorts out, the other switches can be controlled to prevent a large amount of current from flowing to the resistor unit 113.

[0031] If the switch constituting the switching section 110 is an FET, a 12V voltage is supplied as a switching signal from the switching signal supply section 107 to the gate of the FET. Due to the characteristics of the FET, no current flows when the voltage between the gate and drain and the voltage between the gate and source are the same. Therefore, when a 12V voltage is supplied to the gate of the FET to create a difference between the voltage between the gate and drain and the voltage between the gate and source, the voltage between the gate and drain is 48V, but the voltage between the gate and source is 60V, creating a voltage difference between the gate and drain and the gate and source, which allows current to flow to the resistor section 113.

[0032] Furthermore, the control unit 103 can 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 senses the voltage values ​​of the input power supplies, the second power supply KL30 and the first power supply KL40, and transmits this information to the control unit 103. If the voltage value of the second power supply KL30 or the first power supply KL40 falls outside the reference range, the control unit 103 transmits an off signal to the switching signal supply unit 107 to turn off the switching unit 110. At this time, the control unit 103 uses CAN communication to transmit status information of the switching unit 110 to the master control unit and asks whether to maintain the state of 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 supply unit 107, then transmits an on signal to the switching signal supply unit 107 to turn on the switching unit 110.

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

[0035] In this case, after the switching unit 110 is turned off, or when the control unit 103 receives an off signal from the current monitoring unit 108 as described above, it transmits the status 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, it resets the switching signal supply unit 107 and then transmits the 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 ground KL41 side corresponding to the first power supply KL40. This current sensor 112 is used to confirm the normal operation of the loop connecting the first power supply KL40 to the resistor 113 and then to the ground KL41. The control unit 103 receives a current value from the current sensor 112 and compares it with the current value sensed by the current sensor 110. If they do not match (for example, if the ground KL41 is short-circuited), the control unit 103 transmits an off signal to the switching signal supply unit 107 to turn off the switching unit 110.

[0037] Next, the output voltage monitoring unit 109 monitors the voltage input to the resistor unit 113 and the voltage output from the resistor unit 113, and transmits the monitored voltage values ​​to the control unit 103. The voltage value input to the resistor unit 113 is the voltage between the + 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 the resistor unit 113 and the voltage value output from the resistor unit 113 to the master control unit. Furthermore, if the voltage value input to the resistor unit 113 and the voltage value output from the resistor unit 113 fall outside the reference range, the control unit 103 may transmit an off signal to the switching signal supply unit 107 to turn off the switching unit 110.

[0038] In this case, the control unit 103 turns off the switching unit 110, then uses CAN communication to transmit status information of the switching unit 110 to the master control unit and asks whether to keep 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 supply unit 107, 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 a switching unit 110 consisting of at least two switches with a single control unit 103, and integrates the monitoring of various states of the exhaust gas aftertreatment device with an input voltage monitoring unit 104, a temperature monitoring unit 105, a current monitoring unit 108, and an output voltage monitoring unit 109, thereby enabling cost reduction and stable control.

[0040] While this specification contains many features, such features should be interpreted as limiting the scope of the invention or the claims. Furthermore, features described in this specification as individual embodiments may be embodied in combination as a single embodiment. Conversely, diverse features described in this specification as a single embodiment may be embodied individually as diverse embodiments or in appropriate combinations.

[0041] As described above, the present invention is not limited by the embodiments and accompanying drawings, as it can be modified and altered in various ways by a person with ordinary skill in the art to which the present invention belongs, without departing from the technical concept of the invention. (Different aspects of this disclosure) [Item 1] An exhaust gas aftertreatment device, A switching section including at least two switches connected in series, which supplies current from a first power supply to a resistor, A switching signal supply unit that supplies switching signals to the switching unit to selectively control the operation of the switching unit, A switching power supply unit that supplies a second power supply to the switching signal supply unit, A control unit that controls the on / off state of the switching signal supply unit, An interface unit that activates the control unit in response to a control signal received from the master control unit, A first current sensor is located between the switching unit and the resistor unit and senses the current value. The current monitoring unit includes 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. The control unit, An exhaust gas aftertreatment device characterized by prompting the master control unit to turn on or off the switching unit in response to an off signal received from the current monitoring unit, and transmitting an on signal to the switching signal supply unit upon receiving an on signal from the master control unit. [Item 2] The system further includes a temperature monitoring unit that monitors the temperature of the switching unit, The control unit, The exhaust gas aftertreatment device according to item 1, characterized in that it controls the on / off state of the switching signal supply unit based on information received from the temperature monitoring unit. [Item 3] The temperature monitoring unit is a negative temperature coefficient thermistor, The exhaust gas aftertreatment device according to item 2, characterized in that the control unit controls the on / off state of the switching signal supply unit based on the voltage determined by the resistance value of the negative temperature coefficient thermistor. [Item 4] The system further includes a second current sensor provided on the ground side corresponding to the first power supply and sensing a current value, The exhaust gas aftertreatment device according to item 1, characterized in that the control unit transmits an off signal to the switching signal supply unit when the current value sensed by the second current sensor does not match the current value sensed by the first current sensor. [Item 5] The system further includes an input voltage monitoring unit that monitors the voltage values ​​of the first power supply and the second power supply and transmits them to the control unit. The control unit, The exhaust gas aftertreatment device according to item 1, characterized in that an off signal is transmitted to the switching signal supply unit when the voltage value falls outside the reference range. [Item 6] An exhaust gas aftertreatment device, A switching section including at least two switches connected in series, which supplies current from a first power supply to a resistor, A switching signal supply unit that supplies switching signals to the switching unit to selectively control the operation of the switching unit, A switching power supply unit that supplies a second power supply to the switching signal supply unit, A control unit that controls the on / off state of the switching signal supply unit, An interface unit that activates the control unit in response to a control signal received from the master control unit, It includes an output voltage monitoring unit that monitors the voltage input to the resistor and the voltage output from the resistor and transmits this information to the control unit, The control unit, An exhaust gas aftertreatment device characterized in that, when the voltage value monitored by the output voltage monitoring unit falls outside the reference range, an off signal is transmitted to the switching signal supply unit. [Item 7] The interface unit is The exhaust gas aftertreatment device according to item 1, characterized in that the voltage of the second power supply is adjusted to a lower voltage and supplied to the control unit to activate the control unit.

Claims

1. An exhaust gas aftertreatment device, A switching unit that supplies current from the first power supply to the resistor, A switching signal supply unit that supplies switching signals to the switching unit to selectively control the operation of the switching unit, A control unit that controls the on / off state of the switching signal supply unit, An interface unit that activates the control unit in response to a control signal received from the master control unit, It includes an output voltage monitoring unit that monitors the voltage input to the resistor and the voltage output from the resistor and transmits this information to the control unit, The control unit, An exhaust gas aftertreatment device characterized in that, when the voltage value monitored by the output voltage monitoring unit falls outside the reference range, an off signal is transmitted to the switching signal supply unit.

2. The exhaust gas aftertreatment device according to claim 1, wherein the switching unit includes at least two switches connected in series.

3. The exhaust gas aftertreatment device according to claim 1, further comprising a switching power supply unit that supplies a second power supply to the switching signal supply unit.

4. The system further includes an input voltage monitoring unit that monitors the voltage values ​​of the first power supply and the second power supply and transmits them to the control unit, The control unit, The exhaust gas aftertreatment device according to claim 3, characterized in that an off signal is transmitted to the switching signal supply unit when the voltage value falls outside the reference range.

5. The interface unit is The exhaust gas aftertreatment device according to claim 3, characterized in that the voltage of the second power supply is adjusted to a lower voltage and supplied to the control unit to activate the control unit.

6. The system further includes a temperature monitoring unit that monitors the temperature of the switching unit, The control unit, The exhaust gas aftertreatment device according to claim 1, characterized in that it controls the on / off state of the switching signal supply unit based on information received from the temperature monitoring unit.

7. The temperature monitoring unit is a negative temperature coefficient thermistor, The exhaust gas aftertreatment device according to claim 6, characterized in that the control unit controls the on / off state of the switching signal supply unit based on the voltage determined by the resistance value of the negative temperature coefficient thermistor.

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