JP6292543B2 - Engine controller for range extender - Google Patents

Description

  The present invention relates to a range extender engine control device, and more particularly, to a range extender engine control device that controls an engine for driving a generator mounted on an electric vehicle according to a power generation request.

In recent years, in order to extend the cruising range of an electric vehicle, a range extender that generates power with an engine as required has been proposed.
The range extender generates power with the engine when necessary, such as when the remaining capacity of the battery is low or during acceleration or heating when relatively large power is required, and stops the engine when there is no need for power generation Let That is, the range extender engine frequently repeats short-time operation and stoppage (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2015-168379

  If the above operation is stopped for a short time when it is cold, moisture generated by the combustion of the air-fuel mixture will condense on the wall of the combustion chamber and remain on the wall without being discharged as water vapor even after the engine is stopped. There is. In particular, if dew condensation that occurs near the spark plug remains, moisture may permeate between the center electrode of the spark plug and the insulator. In this case, the penetrated moisture is thermally expanded due to a temperature rise during engine operation, and a high stress is applied to the insulator, and the insulator is cracked.

  The present invention has been made to solve the above-described problems of the prior art, and prevents the dew condensation that has occurred near the spark plug from remaining even when the engine is operated and stopped for a short time. Another object of the present invention is to provide a range extender engine control device capable of preventing the spark plug from being damaged.

In order to achieve the above object, a range extender engine control apparatus according to the present invention controls a range extender engine that controls an engine for driving a generator mounted on an electric vehicle according to a power generation request. A cooling water temperature acquiring means for acquiring the temperature of the engine cooling water, an actual operating time acquiring means for acquiring the actual operating time of the engine from the generation to the end of the power generation request, and the cooling water temperature The required operation time acquisition means for acquiring the required operation time of the engine set based on the required spark time acquisition means for acquiring the required spark time of the ignition plug of the engine set based on the coolant temperature, and the power generation request is completed If the engine is stopped and the actual operation time is less than the required operation time, the spark plug is required for the required spark time. And having a, an engine control means for performing a spark caused.
In the present invention configured as described above, the engine control means stops the engine when the power generation request is completed, and the required spark time set based on the engine water temperature when the actual operation time is less than the required operation time. During the cold, the spark plug is used for the required spark time according to the engine water temperature even when condensation occurs in the combustion chamber of the engine when the engine is operated and stopped for a short time when it is cold. By raising the temperature in the vicinity of the spark plug by evaporating, the water condensed in the vicinity of the spark plug can be evaporated and exhausted, so that even if the engine is started and stopped for a short time, extra Prevent condensation from occurring in the vicinity of the spark plug without consuming excessive fuel and damaging the spark plug. It is possible to stop.

In the present invention, the required spark time is preferably set to be shorter as the temperature of the cooling water increases.
In the present invention configured as described above, when the cooling water temperature is relatively high and the time required to evaporate the moisture condensed in the combustion chamber is short, the required spark time is shortened and the cooling water temperature is relatively low. If the time required to evaporate the moisture condensed in the combustion chamber is long, the required spark time can be extended, so that the moisture condensed in the combustion chamber is evaporated after the power generation request is completed. Sparking by the spark plug can be performed only for the time required to make it happen. Therefore, it is possible to prevent dew condensation that has occurred in the vicinity of the spark plug and to prevent the spark plug from being damaged while suppressing power consumption for the spark.

In the present invention, preferably, the required spark time acquisition means acquires the required spark time of the spark plug set based on the temperature of the cooling water and the outside air temperature, and the required spark time becomes shorter as the outside air temperature becomes higher. Is set to be
In the present invention configured as described above, when the outside air temperature is relatively high and the time required to evaporate the moisture condensed in the combustion chamber is short, the required spark time is shortened, and the outside air temperature is relatively If the time required to evaporate the moisture condensed in the combustion chamber is low, the required spark time can be extended, so that the moisture condensed in the combustion chamber can be evaporated after the power generation request is completed. Sparking with the spark plug can be performed only for the time required for this. Therefore, it is possible to prevent dew condensation that has occurred in the vicinity of the spark plug and to prevent the spark plug from being damaged while suppressing power consumption for the spark.

  According to the range extender engine control apparatus of the present invention, even when the engine is operated and stopped for a short time, the dew condensation generated in the vicinity of the spark plug is prevented, and the spark plug is prevented from being damaged. be able to.

1 is a schematic configuration diagram of an electric vehicle according to an embodiment of the present invention. It is a block diagram which shows the system configuration | structure of the range extender by embodiment of this invention. It is a flowchart of the engine control process which the control apparatus of the engine for range extenders by embodiment of this invention controls an engine. It is a diagram which shows the relationship between engine water temperature and the required operation time of an engine. It is a diagram which shows the relationship between engine water temperature and the required spark time of a spark plug.

  Hereinafter, a control device for a range extender engine according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  First, an electric vehicle to which a control device for a range extender engine according to an embodiment of the present invention is applied will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of an electric vehicle according to an embodiment of the present invention.

  As shown in FIG. 1, reference numeral 1 denotes an electric vehicle according to an embodiment of the present invention. This electric vehicle 1 is driven by the engine 3 and the engine 3 to generate electric power, and also serves as a starter when the engine 3 is started. An operable motor generator 5, a battery 7 that is charged by the electric power generated by the motor generator 5, and a traveling motor 11 that drives the drive wheels 9 by at least one of the electric power generated by the motor generator 5 or the electric power from the battery 7; It has.

  An inverter 13 is provided between the motor generator 5, the battery 7 and the traveling motor 11. The electric power generated by the motor generator 5 is supplied to the battery 7 and / or the traveling motor 11 via the inverter 13, and the electric power from the battery 7 is supplied to the motor generator 5 and / or the traveling motor 11. The

  The engine 3 is used only for power generation by the motor generator 5. In the present embodiment, the engine 3 is a hydrogen engine that uses hydrogen gas stored in the hydrogen tank 15 as fuel. The range extender includes these engine 3, motor generator 5, and hydrogen tank 15.

Next, the configuration of the range extender according to the embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block diagram showing a system configuration of the range extender according to the embodiment of the present invention.
As shown in FIG. 2, the engine 3 of the present embodiment is a rotary piston engine. Of the three working chambers (combustion chambers) defined between the rotor of the engine 3 and the rotor housing, an intake passage 17 is connected so as to communicate with the working chamber in the intake stroke, and the operation in the exhaust stroke An exhaust passage 19 is connected to communicate with the chamber.
A throttle valve 21 driven by an actuator such as a stepping motor is disposed in the intake passage 17. A premixing injector 23 for injecting hydrogen supplied from the hydrogen tank 15 into the intake passage 17 is disposed in the intake passage 17. The hydrogen injected by the premixing injector 23 is supplied to the working chamber in the intake stroke in a state of being mixed with air (premixed state).

  Further, the engine 3 is provided with a direct injection injector 25 that directly injects hydrogen supplied from the hydrogen tank 15 into the working chamber, and an ignition plug that ignites the air-fuel mixture in the working chamber.

  In addition, the electric vehicle 1 is provided with sensors 101 to 109 that detect various states. Specifically, these sensors 101 to 109 are as follows. The accelerator opening sensor 101 detects an accelerator opening that is an accelerator pedal opening (corresponding to an amount by which the driver has depressed the accelerator pedal). The vehicle speed sensor 103 detects the speed (vehicle speed) of the electric vehicle 1. The rotation angle sensor 105 detects the rotation angle position of the eccentric shaft of the engine 3. The outside air temperature sensor 107 detects the outside air temperature. The engine water temperature sensor 109 detects the temperature of the cooling water of the engine 3 (engine water temperature). Each of these various sensors 101 to 109 outputs a detection signal corresponding to the detected parameter to a PCM (Power-train Control Module) 29.

  The PCM 29 is a controller based on a well-known microcomputer. The PCM 29 is a central processing unit (CPU) that executes a program, for example, a memory configured to include a RAM and a ROM, and stores a program and data, and an input / output of an electrical signal ( I / O) bus and the like. The PCM 29 outputs control signals to the throttle valve 21, the premixing injector 23, the direct injection injector 25, and the spark plug 27 based on signals input from the various sensors 101 to 109, and controls the engine 3, A control signal is output to the inverter 13 to control the motor generator 5 and the traveling motor 11.

  The PCM 29 controls the inverter 13 to change the operating state of the motor generator 5 into a state in which the engine 3 is started with power from the battery 7 and power generated by the power of the engine 3 to generate electric power for the battery 7 and the traveling motor 11. Switch to the state to supply to.

Further, the PCM 29 controls the inverter 13 according to the remaining capacity (SOC) of the battery 7 and the remaining amount of hydrogen in the hydrogen tank 15, thereby driving the traveling motor 11 with only the electric power from the battery 7. The state is switched between the state driven by only the electric power from the motor generator 5 and the state driven by the electric power from both the battery 7 and the motor generator 5.
The PCM 29 corresponds to the “range extender engine control device” according to the present invention, and functions as the “actual operation time acquisition means”, “required operation time acquisition means”, and “engine control means” according to the present invention.

Next, an engine control process performed by the range extender engine control device will be described with reference to FIGS.
FIG. 3 is a flowchart of an engine control process in which the control device for the range extender engine according to the embodiment of the present invention controls the engine 3. FIG. 4 is a line showing the relationship between the engine water temperature and the required operation time of the engine 3. FIG. 5 is a diagram showing the relationship between the engine water temperature and the required spark time of the spark plug 27.

The engine control process of FIG. 3 is started and executed repeatedly when the ignition of the electric vehicle 1 is turned on and the PCM 29 is powered on.
When the engine control process is started, as shown in FIG. 3, in step S <b> 1, the PCM 29 acquires the detection signals output from the various sensors 101 to 109 as various information related to the driving state of the electric vehicle 1.

  Next, in step S2, the PCM 29 determines whether a power generation request for the motor generator 5 is generated based on the information acquired in step S1. Specifically, the PCM 29 determines that the remaining capacity (SOC) of the battery 7 has decreased below a predetermined lower limit value based on the current or voltage of the battery 7, or the current vehicle speed, engine speed, accelerator opening. When it is determined that the acceleration request level of the driver is equal to or higher than a predetermined level based on the above, or when the power generation by the motor generator 5 is necessary, such as when heating is turned on, judge.

As a result, if no power generation request has occurred, the PCM 29 ends the engine control process because there is no need to operate the engine 3.
On the other hand, when the power generation request is generated, the process proceeds to step S <b> 3, and the PCM 29 starts the engine 3 by driving the motor generator 5 with the electric power from the battery 7 and starts the operation of the engine 3.

  Next, in step S4, the PCM 29 stands by until the power generation request to the motor generator 5 is completed. Specifically, the PCM 29 determines that the remaining capacity of the battery 7 is equal to or higher than the lower limit value of the predetermined value, determines that the driver's acceleration request level is lower than the predetermined level, or heating is turned off. When the power generation by the motor generator 5 is no longer necessary, it is determined that the power generation request has been completed.

  When the power generation request is completed, the process proceeds to step S5, and the PCM 29 acquires the operation time (actual operation time) Tr of the engine 3 from the generation to the end of the power generation request. For example, the PCM 29 acquires the time from when the power generation request is generated in step S2 to the time when the power generation request is completed in step S4 until the time when the power generation request is completed in step S4.

  Subsequently, in step S6, the PCM 29 obtains an operation time (required operation time) Tn of the engine 3 necessary for evaporating the moisture condensed in the working chamber when it is cold. Specifically, the PCM 29 obtains the current acquired in step S1 from a map (created in advance and stored in a memory or the like) that defines the relationship between the engine water temperature and the required operating time for various outside air temperatures. The required operating time Tn corresponding to the current engine water temperature acquired in step S1 is acquired with reference to the map corresponding to the outside air temperature.

As shown in the map of FIG. 4, when the outside air temperature is the same, the required operation time is set shorter as the engine water temperature is higher. This is because the higher the engine water temperature, that is, the higher the temperature of the wall surface of the working chamber, the easier the water on the wall surface evaporates, and the shorter the time required to evaporate the condensed water in the working chamber.
Further, when the engine water temperature is the same, the required operation time is set shorter as the outside air temperature is higher. This is because as the outside air temperature is higher, the engine 3 is less likely to be cooled after the operation is stopped, and the time required to evaporate the moisture condensed in the working chamber is shortened.

Returning to FIG. 3, in step S7, the PCM 29 determines whether or not the actual operation time Tr acquired in step S5 is equal to or longer than the required operation time Tn acquired in step S6.
As a result, when the actual operation time Tr is equal to or longer than the required operation time Tn, it is considered that the moisture condensed in the working chamber at the time of cold has evaporated and exhausted, so the process proceeds to step S8, and the PCM 29 stops the engine 3. Thereafter, the PCM 29 ends the engine control process.

  On the other hand, when the actual operation time Tr is not longer than the required operation time Tn (the actual operation time Tr is less than the required operation time Tn), moisture condensed in the working chamber remains on the wall surface of the working chamber when it is cold. there is a possibility. Therefore, the process proceeds to step S9, and the PCM 29 determines whether or not the operation of the engine 3 can be continued. Specifically, the PCM 29 can charge the battery 7 when the remaining capacity of the battery 7 is less than a predetermined upper limit value, and the remaining amount of hydrogen in the hydrogen tank 15 is equal to or higher than a predetermined lower limit value. It is determined that the operation can be continued.

  As a result, when the operation of the engine 3 can be continued, the process proceeds to step S10, and the PCM 29 continues the operation of the engine 3 until the elapsed time from the generation of the power generation request reaches the required operation time Tn. . Then, after the elapsed time from the generation of the power generation request reaches the required operation time Tn, the process proceeds to step S8, and the PCM 29 stops the engine 3.

  On the other hand, when it is impossible to continue the operation of the engine 3 in step S9, that is, when the remaining capacity of the battery 7 is not less than a predetermined upper limit value and the battery 7 cannot be charged or the hydrogen tank 15 When the remaining hydrogen amount is less than the predetermined lower limit value, the process proceeds to step S11, and the PCM 29 stops the engine 3.

Next, in step S12, the PCM 29 obtains the spark time (necessary spark time) Ts of the spark plug 27 necessary for evaporating the moisture condensed in the vicinity of the spark plug 27 in the working chamber when cold, and the necessity Sparking by the spark plug 27 is performed during the spark time Ts. Here, the “sparking time” is a time for which the spark plug 27 continues to spark repeatedly by intermittently supplying a high voltage for sparking from the ignition coil to the spark plug 27.
Specifically, the PCM 29 obtains the current acquired in step S1 from a map (created in advance and stored in a memory or the like) that defines the relationship between the engine water temperature and the required spark time for various outside air temperatures. The required spark time Ts corresponding to the current engine water temperature acquired in step S1 is acquired with reference to the map corresponding to the outside air temperature. Then, sparking by the spark plug 27 is performed during the necessary spark time Ts.

As shown in the map of FIG. 5, when the outside air temperature is the same, the required spark time is set shorter as the engine water temperature is higher. This is because the higher the engine water temperature, that is, the higher the temperature of the wall surface of the working chamber, the easier the water on the wall surface evaporates, and the shorter the time required to evaporate the condensed water in the working chamber.
Further, when the engine water temperature is the same, the required spark time is set shorter as the outside air temperature is higher. This is because as the outside air temperature is higher, the engine 3 is less likely to be cooled after the operation is stopped, and the time required to evaporate the moisture condensed in the working chamber is shortened.

  Returning to FIG. 3, after step S12, the PCM 29 ends the engine control process.

Next, further modifications of the embodiment of the present invention will be described.
In the above-described embodiment, the PCM 29 operates the engine 3 when it is possible to continue the operation of the engine 3 when the actual operation time Tr is less than the required operation time Tn when the power generation request is completed. It has been described that when it is impossible to continue the operation of the engine 3 and the engine 3 is stopped and the spark plug 27 performs a spark, the actual operation time Tr is required when the power generation request is completed. If the time is less than the time Tn, the engine 3 may be stopped regardless of whether the operation is continued or not, and sparking by the spark plug 27 may be performed for the required spark time Ts.

  In the above-described embodiment, the engine 3 is described as a rotary piston engine using hydrogen gas as a fuel. However, the engine 3 may be an engine using other fuel such as gasoline or biomethanol, or a reciprocating engine.

  Next, effects of the control device for the range extender engine according to the above-described embodiment of the present invention and the modification of the embodiment of the present invention will be described.

  First, the PCM 29 sets the actual operation time Tr of the engine 3 between the generation of the power generation request and the end based on the engine water temperature when the power generation request is completed while the engine 3 is operating in response to the power generation request. When the required operation time Tn is longer than the required operation time Tn, the engine 3 is stopped. When the actual operation time Tr is less than the required operation time Tn, the operation of the engine 3 is continued until the elapsed time from the generation of the power generation request reaches the required operation time Tn. Therefore, even when condensation occurs in the working chamber of the engine 3 by operating and stopping the engine 3 for a short time when it is cold, the engine 3 is kept until the required operating time Tn corresponding to the engine water temperature has elapsed. The operation of the engine 3 can be continued to evaporate and exhaust the water in the working chamber. But, to prevent the condensation occurring in the vicinity of the spark plug 27 remains, it is possible to prevent damage to the spark plug 27.

  In particular, since the required operation time Tn is set to be shorter as the engine water temperature becomes higher, the required operation time Tn is required when the engine water temperature is relatively high and the time required for evaporating moisture condensed in the working chamber is short. If the time Tn is shortened, the engine water temperature is relatively low, and the time required to evaporate the moisture condensed in the working chamber is long, the required operation time Tn can be extended, and the power generation request is thereby completed. After that, the operation of the engine 3 can be continued for the time necessary to evaporate the moisture condensed in the working chamber. Therefore, it is possible to prevent dew condensation that has occurred in the vicinity of the spark plug 27 and prevent damage to the spark plug 27 while suppressing deterioration in fuel consumption.

  Further, since the required operating time Tn is set to be shorter as the outside air temperature becomes higher, the required operation time Tn is required when the outside air temperature is relatively high and the time required to evaporate the moisture condensed in the working chamber is short. If the time Tn is shortened, the outside air temperature is relatively low, and the time required to evaporate the moisture condensed in the working chamber is long, the required operation time Tn can be extended, thereby completing the power generation request. After that, the operation of the engine 3 can be continued for the time necessary to evaporate the moisture condensed in the working chamber. Therefore, it is possible to prevent dew condensation that has occurred in the vicinity of the spark plug 27 and prevent damage to the spark plug 27 while suppressing deterioration in fuel consumption.

  Further, the PCM 29 stops the engine 3 when the power generation request is completed and the actual operation time Tr is less than the required operation time Tn and the operation of the engine 3 cannot be continued. Since sparks are generated by the spark plug 27 during the necessary spark time Ts set based on the water temperature, when condensation occurs in the working chamber of the engine 3 by performing a short-time operation and stop of the engine 3 when cold, Even in a situation where the engine 3 cannot be operated without a power generation request, the spark plug 27 raises the temperature in the vicinity of the spark plug 27 by sparking by the spark plug 27 for the required spark time Ts according to the engine water temperature. The moisture condensed in the vicinity of the engine can be evaporated and exhausted, so that the engine 3 can be operated and stopped for a short time. Even if cormorants, prevents condensation occurring in the vicinity of the spark plug 27 remains, it is possible to prevent damage to the spark plug 27.

  In particular, the required spark time Ts is set to be shorter as the engine water temperature becomes higher. Therefore, when the engine water temperature is relatively high and the time required for evaporating the moisture condensed in the working chamber is short, the necessary spark time is required. If the time Ts is shortened, the engine water temperature is relatively low, and the time required to evaporate the water condensed in the working chamber is long, the required spark time Ts can be extended, thereby completing the power generation request. After that, the spark plug 27 can perform the spark for the time necessary for evaporating the moisture condensed in the working chamber. Therefore, it is possible to prevent dew condensation that has occurred in the vicinity of the spark plug 27 and to prevent the spark plug 27 from being damaged while suppressing power consumption for sparks.

  Further, the necessary spark time Ts is set to be shorter as the outside air temperature becomes higher. Therefore, when the outside air temperature is relatively high and the time required for evaporating moisture condensed in the working chamber is short, the necessary spark time is set. If the time Ts is shortened, the outside air temperature is relatively low, and the time required to evaporate the moisture condensed in the working chamber is long, the required spark time Ts can be extended, and the power generation request is thereby completed. After that, the spark plug 27 can perform the spark for the time necessary for evaporating the moisture condensed in the working chamber. Therefore, it is possible to prevent dew condensation that has occurred in the vicinity of the spark plug 27 and to prevent the spark plug 27 from being damaged while suppressing power consumption for sparks.

  Further, the PCM 29 stops the engine 3 when the power generation request is completed, and sparks by the spark plug 27 during the required spark time Ts set based on the engine water temperature when the actual operation time Tr is less than the required operation time Tn. Therefore, even when condensation occurs in the working chamber of the engine 3 by performing a short-time operation and stop of the engine 3 when cold, the spark by the spark plug 27 during the required spark time Ts according to the engine water temperature. To increase the temperature in the vicinity of the spark plug 27 and to evaporate the moisture condensed in the vicinity of the spark plug 27 and exhaust the exhaust gas. Thus, even when the engine 3 is operated and stopped for a short time, It is possible to prevent dew condensation that has occurred in the vicinity of the spark plug 27 without consuming excess fuel and to prevent the spark plug 2 from remaining. It is possible to prevent the damage.

DESCRIPTION OF SYMBOLS 1 Electric vehicle 3 Engine 5 Motor generator 15 Hydrogen tank 17 Intake passage 19 Exhaust passage 21 Throttle valve 23 Premixing injector 25 Direct injection injector 27 Spark plug 29 PCM
107 Outside air temperature sensor 109 Engine water temperature sensor

Claims (3)

A control device for a range extender engine that controls an engine for driving a generator mounted on an electric vehicle according to a power generation request,
Cooling water temperature acquisition means for acquiring the temperature of the cooling water of the engine;
Actual operation time acquisition means for acquiring the actual operation time of the engine from the generation to the end of the power generation request;
Required operating time acquisition means for acquiring the required operating time of the engine set based on the cooling water temperature;
Required spark time acquisition means for acquiring the required spark time of the ignition plug of the engine set based on the cooling water temperature;
Engine control means for stopping the engine when the power generation request is completed and performing sparking by the spark plug during the required spark time when the actual operation time is less than the required operation time. A control device for a range extender engine.   The range extender engine control device according to claim 1, wherein the required spark time is set to be shorter as the temperature of the cooling water is higher. The necessary spark time acquisition means acquires the required spark time of the spark plug set based on the temperature of the cooling water and the outside air temperature,
The range extender engine control device according to claim 2, wherein the required spark time is set to be shorter as the outside air temperature becomes higher.

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