JP2022036489A - Control device - Google Patents

Abstract

To provide a control device capable of properly controlling a temperature of an electric heating-type catalyst.SOLUTION: A control device 10 includes a power supply portion 11 for supplying electric power for heat generation to an electric heating-type catalyst 200, and an outside air temperature acquisition portion 12 for acquiring an air temperature around a vehicle MV. The power supply portion 11 determines a target power amount on the basis of a soak time which is a length of a period of stop of an internal combustion engine 100, and the air temperature acquired by the outside air temperature acquisition portion 12, and stops the supply of the electric power for heat generation, to the electric heating-type catalyst 200 when an integrated value of the electric power for heat generation supplied to the electric heating-type catalyst 200 reaches the target power amount.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a control device for an electrically heated catalyst.

The vehicle is provided with a catalyst device for purifying the exhaust gas. The catalyst device is a device that purifies harmful substances such as nitrogen oxides contained in exhaust gas by passing them through a high-temperature catalyst. In order for the catalyst device to function, it is necessary to keep the temperature of the catalyst above a predetermined active temperature.

In recent years, for example, for the purpose of purifying exhaust gas from an early stage at the time of cold start, studies have been made on mounting an electric heating type catalyst on a vehicle. In the electric heating type catalyst, the catalyst can be heated by the electric power for heat generation supplied from the outside, and the temperature of the catalyst can be quickly reached to the active temperature. Therefore, even at the time of cold start when the temperature of the exhaust gas is relatively low, it is possible to start the purification of the exhaust gas in a short time. The following Patent Document 1 describes the configuration and the like of such an electrically heated catalyst.

Japanese Unexamined Patent Publication No. 2020-33980

The target electric energy is set in advance as the target value of the electric energy for heat generation in order to bring the temperature of the electric heating type catalyst to the active temperature. When the amount of electric power for heat generation supplied to the electric heating type catalyst reaches the target electric energy, the supply of electric power for heat generation is stopped.

By the way, when the vehicle is cold-started, water may be attached to the inside of the electrically heated catalyst. Such moisture is, for example, condensation of the exhaust gas or the moisture contained in the air and adhering to the wall surface of the flow path through which the exhaust gas passes in the electric heating type catalyst.

When the supply of heat generation power to the electric heating type catalyst is started in the state where water is present inside the electric heating type catalyst, a part of the generated heat raises the temperature of the above water or evaporates. Will be used as heat for. As a result, even if the amount of electric power for heat generation supplied to the electric heating type catalyst reaches the above-mentioned target electric energy amount, the temperature of the electric heating type catalyst may not reach the active temperature yet.

It is an object of the present disclosure to provide a control device capable of appropriately controlling the temperature of an electrically heated catalyst.

The control device according to the present disclosure is the control device (10) of the electrically heated catalyst (200). The electrically heated catalyst to be controlled is mounted on a vehicle (MV) having an internal combustion engine (100). This control device includes a power supply unit (11) that supplies electric power for heat generation to the electric heating type catalyst, and an outside air temperature acquisition unit (12) that acquires the temperature around the vehicle. The power supply unit sets the target electric energy amount based on the length of the period during which the internal combustion engine was stopped, the soak time, and the temperature acquired by the outside temperature acquisition unit, and supplies it to the electric heating type catalyst. When the integrated value of the heat generation power to be generated reaches the target electric energy amount, the supply of the heat generation power to the electric heating type catalyst is stopped.

The amount of water adhering to the electrically heated catalyst is not always constant and changes depending on the soak time and the air temperature. Therefore, in the control device having the above configuration, the power supply unit sets the target electric energy amount based on the soak time and the temperature acquired by the outside air temperature acquisition unit. Since the target electric energy, which is the target value of the electric power for heat generation supplied to the electric heating catalyst, is appropriately set according to the amount of water presumed to have adhered to the electric heating catalyst, electricity is used. It is possible to appropriately control the temperature of the heating type catalyst and surely reach the active temperature.

According to the present disclosure, there is provided a control device capable of appropriately controlling the temperature of an electrically heated catalyst.

FIG. 1 is a diagram schematically showing a configuration of a control device according to the present embodiment and a configuration of a vehicle on which the control device is mounted. FIG. 2 is a cross-sectional view showing the configuration of the electrically heated catalyst shown in FIG. FIG. 3 is a cross-sectional view showing the configuration of the electrically heated catalyst shown in FIG. FIG. 4 is a diagram for explaining temperature control of the electrically heated catalyst. FIG. 5 is a diagram for explaining temperature control of the electrically heated catalyst. FIG. 6 is a flowchart showing a flow of processing executed by the control device shown in FIG.

Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components are designated by the same reference numerals as possible in the drawings, and duplicate description is omitted.

The control device 10 according to the present embodiment is a device for controlling the electric heating type catalyst 200, and is mounted on the vehicle MV together with the electric heating type catalyst 200. Prior to the description of the control device 10, the configuration of the vehicle MV will be described first with reference to FIG.

As shown in FIG. 1, the vehicle MV includes an internal combustion engine 100 and an exhaust pipe 20. The internal combustion engine 100 is a so-called engine, which is a device that generates a driving force for traveling of a vehicle MV by burning fuel. The exhaust pipe 20 is a pipe for guiding the exhaust gas generated by the internal combustion engine 100 to the outside of the vehicle MV and discharging it. Note that, in FIG. 1, only a part of the configuration of the vehicle MV is schematically shown, and the illustration of other configurations included in the vehicle MV, such as intake pipes and wheels, is omitted.

An electric heating type catalyst 200, which is a control target of the control device 10, is provided at a position in the middle of the exhaust pipe 20. The electric heating catalyst 200 is a device for purifying harmful substances such as nitrogen oxides contained in exhaust gas. The configuration of the electrically heated catalyst 200 will be described with reference to FIGS. 2 and 3. FIG. 2 schematically shows a cross section of the electrically heated catalyst 200 when it is cut in a plane parallel to the direction in which the exhaust gas flows. FIG. 3 schematically shows a cross section of the electrically heated catalyst 200 when it is cut in a plane perpendicular to the direction in which the exhaust gas flows. As shown in both figures, the electrically heated catalyst 200 includes an outer cylinder 210, a base material 220, an electrode 230, and a holding member 240.

The outer cylinder 210 is a member for accommodating and holding the base material 220 and the like, which will be described later, inside. The shape of the outer cylinder 210 is generally a cylindrical shape. As shown in FIG. 2, the portion of the exhaust pipe 20 in the vicinity of the outer cylinder 210 is expanded in diameter according to the inner diameter of the outer cylinder 210, and the exhaust pipe 20 having the diameter expanded in this way is the outer cylinder 210. Is connected to. Therefore, the outer cylinder 210 is a part of the exhaust pipe 20 that guides the exhaust gas to the outside.

The base material 220 is a cylindrical member made of conductive ceramics. A plurality of flow paths 221 are formed in a honeycomb shape on the base material 220. Each flow path 221 is formed so as to extend along a direction along the central axis of the base material 220. The direction is the left-right direction in FIG. 2 and the paper depth direction in FIG. A catalyst (not shown) is supported on the base material 220. With such a configuration, the conductivity of the base material 220 is ensured. When the exhaust gas flows through each flow path 221 of the base material 220, it flows while touching the catalyst exposed on the surface of the flow path 221. As the catalyst, various materials known as metal catalysts for purifying exhaust gas, such as a three-way catalyst, can be used.

The electrodes 230 are a pair of electrodes for supplying electric power from the outside to the base material 220 that functions as a catalyst. When a voltage is applied between the electrodes 230, a current flows through the base material 220 made of conductive ceramics, and the generated Joule heat raises the temperature of the base material 220. Therefore, when the temperature of the exhaust gas is relatively low, for example, at the time of cold start, the temperature of the base material 220 is raised by supplying electric power from the electrode 230, and the base material 220 is set to the active temperature in a short time. Can be reached. The "active temperature" is the temperature of the base material 220 that can sufficiently exert the purification performance of the exhaust gas.

Hereinafter, the temperature of the base material 220 is also referred to as “the temperature of the electrically heated catalyst 200”. Further, since the electric power supplied from the pair of electrodes 230 to the base material 220 is the electric power for causing the electric heating type catalyst 200 to generate heat and raising the temperature thereof, the electric power is referred to as "electric power for heat generation" below. It is also written as ".

As shown in FIG. 3, the electrode 230 has a surface electrode portion 231, a protruding portion 232, and a terminal portion 233. The surface electrode portion 231 is an electrode formed so as to cover a part of the surface of the base material 220. The surface electrode portions 231 are formed on the surface of the base material 220 at two locations facing each other with the central axis of the base material 220 interposed therebetween. As the material of the surface electrode portion 231, a metal having conductivity or the like is used.

The protruding portion 232 is a member formed so as to project outward from the surface of each surface electrode portion 231. As the material of the protrusion 232, a conductive metal or the like is used as in the surface electrode portion 231. One end of the protrusion 232 is joined to the surface electrode portion 231. One protrusion 232 is provided for each surface electrode portion 231.

The terminal portion 233 is a rod-shaped member formed so as to project further outward from the end portion of the protruding portion 232 on the side opposite to the surface electrode portion 231. As the material of the terminal portion 233, a metal member having conductivity is also used. One end of the terminal portion 233 is joined to the protruding portion 232. One terminal portion 233 is provided for each protruding portion 232.

The portion of the terminal portion 233 opposite to the protruding portion 232 projects to the outside of the outer cylinder 210 via the insulating holding member 211. Wiring for supplying heat generation power is connected to the outside of the outer cylinder 210 of the terminal portion 233. That is, each terminal portion 233 functions as an electrode terminal for receiving heat generation power from the outside.

As shown in FIG. 3, the entire surface of the conductive member including the surface electrode portion 231 and the protruding portion 232 and the base material 220 is covered with the insulating layer 250. As a result, electrical insulation between these conductive members and the outer cylinder 210 is ensured.

The holding member 240 is a member for holding the base material 220 inside the outer cylinder 210. As the holding member 240, for example, fibrous alumina is used. The holding member 240 is arranged so as to fill the entire gap formed between the inner peripheral surface of the outer cylinder 210 and the outer peripheral surface of the base material 220.

The configuration of the control device 10 will be described with reference to FIG. 1 again. As described above, the control device 10 is a device for controlling the electrically heated catalyst 200. The control device 10 is configured as a computer device having a CPU, ROM, RAM, and the like. The control device 10 includes a power supply unit 11, an outside air temperature acquisition unit 12, and a drive circuit 13 as block elements representing its functions.

The electric power supply unit 11 is a portion that performs a process of supplying electric power for heat generation to the electric heating type catalyst 200. The power supply unit 11 adjusts the magnitude of the heat generation power supplied to the electric heating type catalyst 200 by controlling the operation of the drive circuit 13 described later. The specific contents of the processing performed by the power supply unit 11 will be described later.

The outside air temperature acquisition unit 12 is a unit that performs a process of acquiring the ambient air temperature of the vehicle MV, that is, the outside air temperature. The outside air temperature acquisition unit 12 acquires the outside air temperature based on a signal from an outside air temperature sensor (not shown) provided in the vehicle MV. As such an outside air temperature sensor, for example, a thermistor provided in the middle of an intake pipe (not shown) for supplying air to the internal combustion engine 100 can be used. Instead of such an aspect, the outside air temperature acquisition unit 12 acquires, for example, weather information provided from an external server by wireless communication, and acquires the outside air temperature at the position of the vehicle MV based on the weather information. It may be that.

The drive circuit 13 is a circuit provided for supplying electric power for heat generation to the electric heating type catalyst 200. As shown in FIG. 2, the drive circuit 13 includes a cutoff circuit 131, a switching circuit 132, and a battery 133.

The cutoff circuit 131 is a circuit for cutting off the supply of heat generation electric power to the electric heating type catalyst 200. When the electric power for heat generation is supplied to the electric heating type catalyst 200, the cutoff circuit 131 is closed. The operation of the cutoff circuit 131 is controlled by the power supply unit 11.

The switching circuit 132 is a circuit configured by a switching element (not shown), and switches the opening and closing of the power path connecting the battery 133 and the electrically heated catalyst 200. The operation of the switching circuit 132 is controlled by the power supply unit 11. The power supply unit 11 adjusts the magnitude of the heat generation power supplied to the electric heating type catalyst 200 by adjusting the duty in the opening / closing operation of the switching circuit 132.

The battery 133 is a power storage device that is a source of heat generation power, and is, for example, a lithium ion battery. As the battery 133, an auxiliary battery mounted on the vehicle MV is used. Instead of such an embodiment, the battery 133 may be provided as a dedicated power storage device for supplying electric power for heat generation to the electric heating type catalyst 200.

The drive circuit 13 of this embodiment is built in the control device 10. Instead of such an embodiment, the drive circuit 13 may be configured as a device separate from the control device 10 and may be arranged outside the control device 10.

The outline of the temperature control of the electric heating type catalyst 200 performed by the control device 10 will be described. FIG. 4A shows an example of a time change of the voltage value of the heat generating power supplied to the electrically heated catalyst 200. As described above, the power supply unit 11 adjusts the duty in the opening / closing operation of the switching circuit 132, thereby adjusting the magnitude of the heat generation power. In the example shown by the line L20 of FIG. 4A, the switching operation of the switching circuit 132 is repeated during the period from time t10 to time t13, and the electric heating type catalyst 200 is supplied with heat generation power.

FIG. 4B shows an example of the time change of the temperature of the electrically heated catalyst 200. When the supply of the heating power to the electric heating type catalyst 200 is started at time t10, the temperature of the electric heating type catalyst 200 gradually rises as shown by the line L30 and the line L31. In the present embodiment, the target temperature T10 is set as a temperature equal to or higher than the active temperature of the electrically heated catalyst 200. The supply of heat generation power to the electric heating type catalyst 200 is basically continued until the temperature of the electric heating type catalyst 200 reaches the target temperature T10.

FIG. 4C shows an integrated value of the heat generation power supplied to the electrically heated catalyst 200, that is, an example of the time change of the electric energy. When the supply of heat-generating electric power to the electric heating catalyst 200 is started at time t10, the amount of electric power gradually increases as shown by the line L40 and the line L41. This amount of electric power can also be said to be an integrated value of the energy supplied to the electrically heated catalyst 200.

In the present embodiment, a target value for the amount of heat generation electric power supplied to the electrically heated catalyst 200 is set. The target value will also be referred to as "target electric energy" below. The target electric energy amount is preset as a value of energy required to bring the temperature of the electrically heated catalyst 200 to at least the above-mentioned target temperature T10. The line L40 in FIG. 4C is an example of the time change of the electric energy when E10 is set as the target electric energy. The line L41 in FIG. 4C is an example of the time change of the electric energy when E11 is set as the target electric energy. In the present embodiment, a constant value is not always set as the target electric energy, but a target electric energy having a different value is set each time depending on the situation.

By the way, at the time of cold start of the vehicle MV, moisture may be attached to the inside of the electric heating type catalyst 200. Such moisture is, for example, dew condensation of the exhaust gas or the moisture contained in the air and adheres to the inner wall surface of the flow path 221 through which the exhaust gas passes in the electric heating type catalyst 200. The amount of water adhering to the inside of the electrically heated catalyst 200 varies depending on the length of time (soak time) elapsed until the internal combustion engine 100 is started, the temperature and humidity at that time, and the like.

The line L30 shown in FIG. 4B is an example of the temperature change of the electric heating type catalyst 200 when the supply of the electric power for heat generation is started in the state where the water content inside the electric heating type catalyst 200 is 0. Is shown. In this case, almost all of the energy of the electric power for power generation supplied to the electrically heated catalyst 200 is used for raising the temperature of the base material 220. Therefore, as shown by the line L30, the temperature of the electrically heated catalyst 200 rises at a relatively high rate after the time t10 when the supply of the power for heat generation is started.

E10 shown in FIG. 4C should be set as a target electric energy amount in order to bring the temperature of the electric heating type catalyst 200 to T10 in a state where the water content inside the electric heating type catalyst 200 is 0. This is the ideal value. In the example shown by the line L40 of FIG. 4C, when the amount of electric power supplied to the electric heating type catalyst 200 reaches the target electric energy amount E10 at time t13, it is shown by the line L20 of FIG. 4A. At this point, the supply of power for power generation is stopped. As shown by the line L30 in FIG. 4B, the temperature of the electrically heated catalyst 200 reaches the target temperature T10 at a timing substantially equal to this time t13. It can also be said that E10 is the minimum amount of electric power for heat generation required to reach T10 at the temperature of the electric heating type catalyst 200 in a state where moisture is not attached.

The line L21 of FIG. 4A, the line L31 of FIG. 4B, and the line L41 of FIG. 4C all have a relatively large amount of water adhering to the inside of the electrically heated catalyst 200. An example is shown in the case where the heat generation power supply is started in the state.

In this case, a part of the energy of the electric power for power generation supplied to the electric heating type catalyst 200 is used for raising the temperature of the base material 220, while the other part is used for raising the temperature of the above-mentioned water and the temperature of the water. , Used as energy to evaporate water. Therefore, when the same E10 as in the previous example is set as the target electric energy, the temperature of the electrically heated catalyst 200 cannot reach the target temperature of T10.

E11 shown in FIG. 4C is set as a target electric energy amount in order to bring the temperature of the electric heating type catalyst 200 to T10 in a state where water is attached to the inside of the electric heating type catalyst 200. It is the ideal value of the power value.

In this case, as shown by line L31 in FIG. 4B, when the supply of power for power generation is started at time t10, the temperature of the electrically heated catalyst 200 starts to rise. At a time t11 thereafter, when the temperature of the electrically heated catalyst 200 rises to, for example, about 100 ° C., the water adhering to the electrically heated catalyst 200 begins to boil. For some time from time t11, most of the energy of the supplied power for power generation is consumed as latent heat for boiling water. Therefore, in the period from the time t11 to the time t12 when the water content is completely evaporated, the temperature of the electrically heated catalyst 200 hardly rises.

After time t12, there is no water inside the electrically heated catalyst 200. Therefore, almost all of the energy of the electric power for power generation supplied to the electrically heated catalyst 200 is used for raising the temperature of the base material 220.

The supply of electric power for power generation is continued until the time t14 when the amount of electric power supplied to the electric heating type catalyst 200 reaches the target electric energy of E11. When the amount of electric power supplied to the electric heating catalyst 200 reaches the target electric energy amount E11 at time t14, the supply of electric power for power generation is stopped at this point as shown by the line L21 in FIG. 4 (A). .. Further, as shown by the line L31 in FIG. 4B, the temperature of the electrically heated catalyst 200 reaches the target temperature T10 at a timing substantially equal to this time t14. It can also be said that E11 is the minimum amount of electric power for heat generation required to bring the temperature of the electric heating type catalyst 200 in a state where water is attached to reach T10.

FIG. 5A shows an example of the time change of the temperature of the electrically heated catalyst 200, as in FIG. 4B. Similar to FIG. 4C, FIG. 5B shows an integrated value of heat generation power supplied to the electrically heated catalyst 200, that is, an example of time change of the electric energy. The wire L50 and the wire L60 show an example in which the power generation for heat generation is started in a state where moisture does not adhere to the inside of the electric heating type catalyst 200. The wire L51 and the wire L61 show an example in which the power generation for heat generation is started in a state where a relatively small amount of water is attached to the inside of the electric heating type catalyst 200. The wire L52 and the wire L62 show an example in which the power generation for heat generation is started in a state where a relatively large amount of water is attached to the inside of the electric heating type catalyst 200.

As shown by the wire L60, when water does not adhere to the inside of the electrically heated catalyst 200, it is preferable to set a relatively small E20 as the target electric energy. In this case, at a relatively fast time t21, the integrated value of the electric power for power generation reaches E20, and the temperature of the electrically heated catalyst 200 reaches the target temperature T10.

As shown by the wire L61, when a relatively small amount of water is attached to the inside of the electrically heated catalyst 200, it is preferable to set E21, which is larger than E20, as the target electric energy. In this case, at time t22 after time t21, the integrated value of the power generation power reaches E21, and the temperature of the electrically heated catalyst 200 reaches the target temperature T10.

As shown by the wire L62, when a relatively large amount of water is attached to the inside of the electrically heated catalyst 200, it is preferable that E22, which is larger than E21, is set as the target electric energy. In this case, at time t23 after time t22, the integrated value of the power generation power reaches E22, and the temperature of the electrically heated catalyst 200 reaches the target temperature T10.

The above E20, E21, and E22 are ideal values of values that should be set as the target electric energy in order to bring the temperature of the electrically heated catalyst 200 to T10, respectively. If the target electric power amount is appropriately set according to the amount of water contained in the electric heating type catalyst 200, as shown in FIG. 5A, in any case, the electric heating type catalyst 200 The temperature can reach T10.

However, since it is difficult to accurately obtain the amount of water contained in the electrically heated catalyst 200, it is difficult to set an ideal target electric energy such as E20. Therefore, the power supply unit 11 of the control device 10 according to the present embodiment has a target power amount required to bring the temperature of the electrically heated catalyst 200 to at least T10 based on a parameter that can affect the amount of water. Is to be set. That is, the power supply unit 11 does not set the target electric energy for accurately matching the temperature of the electric heating type catalyst 200 with the target temperature T10, but sets the temperature of the electric heating type catalyst 200 to at least the target temperature T10 or higher. It is decided to set a target electric energy that can be increased to.

In order to realize such temperature control, the flow of processing executed by the control device 10 will be described with reference to FIG. The series of processes shown in FIG. 6 is mainly executed by the power supply unit 11 of the control device 10. The series of processes shown in FIG. 6 is started at an arbitrary timing during the period in which the internal combustion engine 100 is operating.

In the first step S01 of the process, it is determined whether or not the internal combustion engine 100 has stopped. The operating state of the internal combustion engine 100 can be acquired by communication from, for example, a higher-level ECU (not shown) that controls the internal combustion engine 100. When the internal combustion engine 100 is not stopped and is in operation, the process of step S01 is executed again. When the internal combustion engine 100 is stopped, the process proceeds to step S02.

In step S02, the soak time _ts is updated. The soak time t _s is the length of the period during which the internal combustion engine 100 has been stopped. At a time point before the processing of FIG. 6 is started, the initial value of ts is set to ₀ . In step _S02 , the value of the soak time ts is updated based on the following equation (1).
t _s = t _s + Δt ... (1)

The second term “Δt” on the left side of the equation (1) is the time elapsed from the time when the process of step S02 was performed last time to the time when the process is performed this time.

In step S03 following step S02, it is determined whether or not the electric heating type catalyst 200 is energized, that is, whether or not the supply of heat generation power is started. For example, when the power supply unit 11 starts supplying the heat generation power by a command from a higher-level ECU (not shown), it is determined as Yes in step S03. The control device 10 may start the supply of the heat generation power based on its own judgment without being based on the command from the host ECU.

If the electric heating catalyst 200 has not yet been energized in step S03, the processes after step S02 are executed again, and the value of the soak time _ts is updated. When the energization of the electrically heated catalyst 200 is started, the process proceeds to step S04. At the time of shifting to step _S04 , the value of the soak time ts is fixed. From this point in time, electric power for heat generation is supplied to the electric heating type catalyst 200, but the value of the target electric energy amount is undecided at this point.

In step S04, the process of acquiring the _Tamb , which is the outside air temperature, is performed by the outside air temperature acquisition unit 14. This _Tamb is the temperature around the vehicle MV at the time when the electric heating type catalyst 200 is started to be energized.

In step S05 following step S04, the power supply unit 11 performs a process of calculating E _max , which is a target electric energy amount, based on the outside air temperature _Tamb and the soak time _ts . Similar to E22 in the example of FIG. 5, this E _max sets the temperature of the electric heating catalyst 200 to a predetermined target temperature T10 when the amount of water adhering to the inside of the electric heating catalyst 200 is the largest. It is the target amount of power required to reach the target. "When the amount of water adhering to the inside of the electric heating catalyst 200 is the largest" is, for example, when the soak time _ts has elapsed while the humidity of the electric heating catalyst 200 is 100%. That is.

Specifically, in step S05, the humidity around the electrically heated catalyst 200 is 100%, and the temperature around the vehicle MV is _Tamb , and the soak time is t _s . Assuming that the amount of water expected to be accumulated in the electric heating catalyst 200 is present inside the electric heating type catalyst 200, it is necessary for the electric heating type catalyst 200 in such a state to reach the target temperature T10. The amount of electric power is set as the target electric energy E _max .

The correspondence between the combination of T _amb and _ts and the set E _max may be obtained in advance by an experiment or the like and stored in a storage device (not shown) included in the control device 10. Expressing the correspondence by a function called f (), E _max can be calculated based on the following equation (2).
E _max = f (T _amb , t _s ) ... (2)

After the value of the target electric energy E _max is set in step S05, the process proceeds to step S06. _In step S06, a process of updating the value of Ein, which is the electric energy of the heat generating electric power supplied to the electric heating type catalyst 200, is performed. Before the processing of FIG. 6 is started, the initial value of E _in is set to 0. _In step S06, the value of Ein is updated based on the following equation (3).
E _in = E _in + P _in Δt ... (3)

The second term “ _Pin ” on the left side of the equation (3) is the value of the heat generation power supplied to the electrically heated catalyst 200 at present. “Δt” in the same paragraph is the time elapsed from the time when the process of step S06 was performed last time to the time when the process is performed this time.

In step S07 following step S06, it is determined whether or not the value of E _in is equal to or greater than the value of the target electric energy E _max set in step S05. If the value of E _in is less than the value of E _max , the processing after step S06 is executed again. When the value of E _in is equal to or greater than the value of E _max , the process proceeds to step S08. In step S08, a process of stopping the supply of heat generation power to the electrically heated catalyst 200 is performed. As a result, the power supply process is completed.

At the time when the treatment of step S08 is executed, the temperature of the electrically heated catalyst 200 should be at least the target temperature T10 or higher. The reason is that the actual amount of water adhering to the inside of the electrically heated catalyst 200 is equal to or equal to the amount of water in a situation where the target power amount should be set to at least E _max (humidity 100% in this example). It should be less than that.

As described above, in the control device 10 according to the present embodiment, the power supply unit 11 has the soak time, which is the length of the period during which the internal combustion engine 100 has been stopped, and the temperature acquired by the outside temperature acquisition unit 12. The target power amount is set based on the above, and when the integrated value of the heat generation power supplied to the electric heating type catalyst 200 reaches the target power amount, the supply of the heat generation power to the electric heating type catalyst 200 is stopped. It is configured as follows.

The soak time and the outside air temperature are parameters that affect the amount of water adhering to the electrically heated catalyst 200. In the present embodiment, the target electric energy, which is the target value of the electric power for heat generation supplied to the electric heating type catalyst 200, is appropriate according to the amount of water presumed to have adhered to the electric heating type catalyst 200. Since it is set to, it is possible to appropriately control the temperature of the electric heating type catalyst 200 and surely reach the active temperature.

The electric power supply unit 11 of the control device 10 according to the present embodiment targets the electric heating catalyst 200 in a state of containing a predetermined amount of water as the amount of electric power required to reach a predetermined target temperature (T10). Set the electric energy (E _max ).

The above-mentioned "predetermined amount" is a value ( _Tamb ) in which the humidity around the electrically heated catalyst 200 is 100% and the air temperature around the vehicle MV is acquired by the outside air temperature acquisition unit 12. In the state, it is the amount of water accumulated inside the electrically heated catalyst 200 during the soak time ( _ts ).

The water content can be said to be the maximum amount of water that is expected to be accumulated inside the electrically heated catalyst 200 during the soak time _ts . Since the actual amount of water is less than that, when E _max is input as the target electric power amount, the temperature of the electrically heated catalyst 200 will surely rise to at least the target temperature T10 or more.

By the above method, the power supply unit 11 surely raises the temperature of the electrically heated catalyst 200 to the target temperature T10 or more without accurately calculating the water content by, for example, measuring the actual humidity. , It is possible to bring the purification performance of the electrically heated catalyst 200 into a state where it can be exhibited.

As described above, the above-mentioned "predetermined amount" when setting the target electric energy E _max means that the humidity around the electric heating catalyst 200 is 100% and the air temperature around the vehicle MV is 100%. , The amount of water accumulated inside the electrically heated catalyst 200 during the soak time ( _ts ) in the state of the value ( _Tamb ) acquired by the outside air temperature acquisition unit 14. That is, in the present embodiment, the amount of water stored in the electric heating catalyst 200 is set under the assumption that the humidity around the electric heating catalyst 200 is 100%, and the target electric power is set on the premise of the setting. The quantity E _max is set.

However, the above humidity may be a value different from 100%. For example, under the assumption that the humidity around the electric heating catalyst 200 is a predetermined value or more (for example, 95% or more), the amount of water accumulated in the electric heating catalyst 200 is set, and on the premise of the setting, the amount of water is set. The target electric energy E _max may be set. That is, the above-mentioned "predetermined amount" when setting the target electric energy E _max means that the humidity around the electric heating catalyst 200 is equal to or higher than a predetermined value, and the temperature around the vehicle MV is the outside air temperature acquisition. It may be the amount of water accumulated inside the electrically heated catalyst 200 during the soak time ( _ts ) in the state of the value ( _Tamb ) acquired in the part 14.

The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. These specific examples with appropriate design changes by those skilled in the art are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element provided in each of the above-mentioned specific examples, its arrangement, conditions, a shape, and the like are not limited to those exemplified, and can be appropriately changed. The combinations of the elements included in each of the above-mentioned specific examples can be appropriately changed as long as there is no technical contradiction.

The controls and methods described in this disclosure are dedicated to one or more provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. It may be realized by a computer. The control device and control method described in the present disclosure may be realized by a dedicated computer provided by configuring a processor including one or more dedicated hardware logic circuits. The control device and control method described in the present disclosure comprises a combination of a processor and memory programmed to perform one or more functions and a processor including one or more hardware logic circuits. It may be realized by one or more dedicated computers. The computer program may be stored on a computer-readable non-transitional tangible recording medium as an instruction executed by the computer. The dedicated hardware logic circuit and the hardware logic circuit may be realized by a digital circuit including a plurality of logic circuits or an analog circuit.

MV: Vehicle 10: Control device 11: Power supply unit 12: Outside air temperature acquisition unit 100: Internal combustion engine 200: Electric heating type catalyst

Claims (4)

It is a control device (10) of an electric heating type catalyst (200), and is
The electrically heated catalyst is mounted on a vehicle (MV) having an internal combustion engine (100).
A power supply unit (11) that supplies heat generation power to the electric heating type catalyst, and
It is equipped with an outside air temperature acquisition unit (12) that acquires the air temperature around the vehicle.
The power supply unit
The target electric energy is set based on the soak time, which is the length of the period during which the internal combustion engine has been stopped, and the temperature acquired by the outside air temperature acquisition unit.
A control device that stops the supply of heat generation power to the electric heating catalyst when the integrated value of the heat generation power supplied to the electric heating catalyst reaches the target electric energy. The power supply unit
The control device according to claim 1, wherein the target electric power amount is set as an electric power amount required for the electric heating type catalyst containing a predetermined amount of water to reach a predetermined target temperature. The predetermined amount is
The electric heating during the soak time in a state where the humidity around the electric heating catalyst is equal to or higher than a predetermined value and the temperature around the vehicle is a value acquired by the outside air temperature acquisition unit. The control device according to claim 2, which is the amount of water accumulated inside the catalyst. The control device according to claim 3, wherein the predetermined value is 100%.

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