JP5858775B2 - Control device - Google Patents

Description

  The present invention relates to an internal combustion engine mounted on a vehicle or the like and a control device that controls a plurality of external loads that operate using the output of the internal combustion engine.

  Various external loads that operate using the output of an internal combustion engine that generates the driving force for driving are mounted on the automobile (see, for example, the following patent document).

  More specifically, the compressor of the air conditioner receives a rotational torque from the crankshaft of the engine, performs a refrigerant compression operation, and contributes to cooling of the interior of the vehicle. The blower (or fan) attached to the air conditioner and the defogger that removes the fog on the rear glass operate with power supplied from the on-board battery or alternator (generator), but generate that power. The alternator also generates electric power by receiving rotational torque from the crankshaft. That is, the compressor directly uses the output of the internal combustion engine, and the blower and the defogger indirectly use the output of the internal combustion engine (via conversion from mechanical energy to electrical energy by the alternator).

  When multiple external loads are activated simultaneously at the time of deceleration when the engine speed drops or when the engine speed is lower than the original (when idling, etc.), in order to ensure the output necessary for the operation of these external loads, It is customary to execute correction control for increasing the intake air amount and the fuel injection amount charged in the cylinders of the internal combustion engine. However, this correction may not be in time for the sudden increase in load on the internal combustion engine, and the engine speed may drop significantly. In the worst case, engine stall may occur.

JP 2010-138877 A

  An object of the present invention is to avoid the problem that the engine rotational speed greatly drops when the operation of a plurality of external loads is requested at the same time.

In the present invention, the internal combustion engine and a plurality of external loads that operate using the output of the internal combustion engine are controlled, and the engine speed is equal to or less than a predetermined value, or the amount of decrease in the engine speed per unit time is In a case where at least one of the conditions of being equal to or greater than a predetermined condition is satisfied, when the operation requests for a plurality of external loads are generated substantially simultaneously or continuously within a predetermined time, the external loads are activated according to a predetermined priority order. And detecting a charge amount of a battery that supplies electric power necessary for at least one operation of the external load or a power generation amount of an alternator, and a state in which the charge amount is relatively high or the power generation amount is relatively low, The priority is made different depending on whether the charge amount is relatively low or the power generation amount is relatively high, and the charge amount is relatively high. When the power generation amount is relatively low, the external load is activated in a priority order that does not depend on the power consumption, and when the charge amount is relatively low or the power generation amount is relatively high, the power consumption is A control device for starting the external load in ascending order was configured.

  According to the present invention, it is possible to avoid the problem that the engine speed greatly drops when the operation of a plurality of external loads is requested at the same time.

The figure which shows the whole structure of the internal combustion engine in one Embodiment of this invention. The figure which shows the electric circuit for the control apparatus in the same embodiment to operate the compressor of an air conditioner, and various electric loads. The figure which shows the procedure of the process which the control apparatus in the embodiment performs.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of an internal combustion engine for a vehicle in the present embodiment. This internal combustion engine is of a direct injection type, and includes a plurality of cylinders 1 (one of which is shown in FIG. 1), an injector 11 for injecting fuel into each cylinder 1, An intake passage 3 for supplying intake air to the cylinder 1, an exhaust passage 4 for discharging exhaust from each cylinder 1, an exhaust turbocharger 5 for supercharging intake air flowing through the intake passage 3, and an exhaust passage And an external EGR device 2 that recirculates EGR (Exhaust Gas Recirculation) gas from 4 to the intake passage 3.

  The intake passage 3 takes in air from the outside and guides it to the intake port of the cylinder 1. On the intake passage 3, an air cleaner 31, a compressor 51 of the supercharger 5, an intercooler 32, an electronic throttle valve 33, a surge tank 34, and an intake manifold 35 are arranged in this order from the upstream side.

  The exhaust passage 4 guides exhaust generated as a result of burning fuel in the cylinder 1 from the exhaust port of the cylinder 1 to the outside. An exhaust manifold 42, a drive turbine 52 for the supercharger 5, and a three-way catalyst 41 are disposed on the exhaust passage 4. In addition, an exhaust bypass passage 43 that bypasses the turbine 52 and a waste gate valve 44 that is a bypass valve that opens and closes the inlet of the bypass passage 43 are provided. The waste gate valve 44 is an electric waste gate valve that can be opened and closed by inputting a control signal l to the actuator, and a DC servo motor is used as the actuator.

  The exhaust turbocharger 5 is configured such that the drive turbine 52 and the compressor 51 are connected and linked in a coaxial manner. Then, the driving turbine 52 is rotationally driven by using the energy of the exhaust gas, and the compressor 51 is pumped by using the rotational force, whereby the intake air is pressurized and compressed (supercharged) and sent to the cylinder 1.

  The external EGR device 2 realizes a so-called high-pressure loop EGR. The inlet of the external EGR passage is connected to a predetermined location upstream of the turbine 52 in the exhaust passage 4. The outlet of the external EGR passage is connected to a predetermined location downstream of the throttle valve 33 in the intake passage 3, specifically to a surge tank 34. An EGR cooler 21 and an EGR valve 22 are also provided on the external EGR passage.

  A vehicle equipped with an internal combustion engine is accompanied by a plurality of external loads. Specific examples of external loads include air conditioner refrigerant compression compressors, various electrical loads such as air conditioner blowers, rear glass defoggers, audio equipment, car navigation systems, lighting (heads) Lamps, tail lamps, fog lamps, turn signals (turn signal lamps, etc.), radiator fans for cooling cooling water, electric power steering devices, and the like.

  The compressor receives rotational torque from the crankshaft of the internal combustion engine and is rotationally driven to compress the refrigerant. As shown in FIG. 2, a magnet clutch 61 that can be connected and disconnected is interposed between the compressor and the crankshaft. When operating the air conditioner, the magnet clutch 61 is energized with current from the in-vehicle battery 62 and / or the alternator 63 and the magnet clutch 61 is engaged. On the contrary, when the air conditioner is not operated, the magnet clutch 61 is not energized and the clutch 61 is disconnected. Energization and disconnection of the magnet clutch 61 is performed by turning ON / OFF the relay switch 64.

  A motor 66 that rotationally drives the blower for blower and a heating wire heater 68 laid on the rear glass as a defogger operate by receiving power supply from the battery 62 and / or the alternator 63. Energization and interruption of the motor 66 and the heater 68 are performed by turning on / off the relay switch 67 or starting / extinguishing a semiconductor switching element (power device represented by a power transistor, power MOSFET, etc.) 69.

  Audio devices, car navigation systems, illumination lights, motors for rotating the radiator fan, and other electrical loads are the same as described above.

  An alternator 63, which is a source of power supply to the electric load, is rotationally driven in response to transmission of rotational torque from the crankshaft of the internal combustion engine to generate electric power. The alternator 63 is connected to the crankshaft via a winding transmission mechanism having a belt and a pulley as elements. The magnitude of the voltage generated and output by the alternator 63 can be controlled via the regulator 65. The regulator 65 is a known IC type attached to the alternator 63 and performs a switching operation for switching ON / OFF the energization of the field coil of the alternator 63.

  The output voltage of the alternator 63, that is, the voltage induced in the stator coil of the alternator 63 increases in proportion to fDUTY which is the DUTY ratio of the field current flowing through the field coil. The regulator 65 receives a signal r for instructing an output voltage of an alternator from an ECU (Electronic Control Unit) 0, and performs PWM control for adjusting fDUTY so as to realize the instructed output voltage. With this PWM control, the power generated by the alternator 63 can be increased or decreased. The amount of power generated by the alternator 63, in other words, the amount of charge to the battery 62 and / or the amount of power supplied to the electrical load increases as fDUTY increases and decreases as fDUTY decreases.

  In the regulator 65 of the vehicular alternator 63 that is widely used, the output voltage of the alternator 63 can be switched to two stages, for example, 14.5V or 12.8V. In this case, the ECU 0 inputs to the regulator 65 a signal r that instructs whether the output voltage of the alternator 63 is HI potential = 14.5V or LO potential = 12.8V.

  Incidentally, as the regulator 65, a linear regulator capable of continuously changing the output voltage of the alternator 63 within a predetermined range, for example, between 12V and 15.5V can be adopted. In this case, the ECU 0 inputs a signal r that instructs the regulator 65 to set the output voltage of the alternator 63 to any value within the range.

  The LO potential or minimum output voltage of the alternator 63 is preferably set to a voltage lower than the voltage of the battery 62 or a low voltage close to the voltage of the battery 62. Although the battery voltage varies depending on the state of charge of the battery 62 and the like, it is usually a predetermined voltage, for example, 12 V or more.

  The alternator 63 becomes a mechanical load when viewed from the internal combustion engine. When the output voltage of the alternator 63 exceeds the voltage of the battery 62, the battery 62 is charged and power is supplied from the alternator 63 to the electric load. That is, the alternator 63 performs the work of generating electric energy by consuming energy of rotation of the crankshaft. The amount of charge to the battery 62 and the amount of power supplied to the electrical load depend on the potential difference between the output voltage of the alternator 63 and the battery voltage.

  Conversely, when the output voltage of the alternator 63 is less than or close to the battery voltage, the battery 62 is not charged, and no power is supplied from the alternator 63 to the electric load (power supply from the battery 62 to the electric load). Sometimes). That is, the alternator 63 does not perform work that consumes the energy of rotation of the crankshaft, or the work is reduced.

  In short, when a high output voltage is commanded from the ECU 0 to the regulator 65, the mechanical load of the alternator 63 with respect to engine rotation increases, and when a low output voltage is commanded, the mechanical load of the alternator 63 with respect to engine rotation decreases.

  The ECU 0 as an internal combustion engine and external load control device is a microcomputer system having a processor, a memory, an input interface, an output interface, and the like.

  The input interface includes a vehicle speed signal a output from a vehicle speed sensor that detects the actual vehicle speed of the vehicle, an engine rotation signal b output from an engine rotation sensor that detects the rotation angle and engine speed of the crankshaft, and depression of an accelerator pedal. The accelerator opening signal c output from an accelerator opening sensor that detects the amount or the opening of the throttle valve 33 as an accelerator opening (so-called required output), the intake air temperature in the intake passage 3 (in particular, the surge tank 34), and An intake air temperature / intake pressure signal d output from a temperature / pressure sensor that detects intake pressure (or supercharging pressure), and an indicator (battery current, battery voltage, and / or battery) that indicates the state of charge of the in-vehicle battery 62 Battery status signal e output from the sensor detecting the temperature), each of the air conditioner and various electric loads , The operation request signal f regarding whether or not to operate this, the refrigerant pressure signal g output from the pressure sensor that detects the refrigerant pressure of the air conditioner, and the water temperature sensor that detects the cooling water temperature of the engine. A coolant temperature signal h or the like is input. The operation request signal f is a signal issued from an operation switch (or control panel) for each air conditioner or electric load, which is manually operated by a driver or passenger who desires to operate the air conditioner and various electric loads. Or a signal issued from an auto air conditioner ECU or the like that controls the auto air conditioner system.

  From the output interface, the ignition signal i for the spark plug (ignition coil), the opening operation signal j for the EGR valve 22, the opening operation signal k for the throttle valve 33, and the waste gate valve 44 An opening operation signal l, a fuel injection signal m for the injector 11, an electric circuit for energizing a clutch fastening signal o, a motor 66, a heater 68 and other electric loads for a switch 64 on the electric circuit for energizing the magnet clutch 61 The switch ON signals o, p, q are output to the upper switches 67, 69, and the voltage instruction signal r is output to the voltage regulator 65 that controls the voltage generated by the alternator 63.

  The processor of the ECU 0 interprets and executes a program stored in the memory in advance, calculates operation parameters, and controls the operation of the internal combustion engine. The ECU 0 acquires various information a, b, c, d, e, f, g, and h necessary for operation control of the internal combustion engine via the input interface, knows the engine speed, and is filled in the cylinder 1. Estimate the intake volume. Based on the engine speed and intake air amount, the required fuel injection amount, fuel injection timing (including the number of times of fuel injection for one combustion), fuel injection pressure, ignition timing, EGR amount (or EGR rate) In addition, various operating parameters such as ON / OFF of the EGR valve 22, the compressor of the air conditioner, ON / OFF of the blower, ON / OFF of the defogger, ON / OFF of various electric loads, output voltage by the alternator 63, and the like are determined. Thus, various control signals i, j, k, l, m, o, p, q, r corresponding to the operation parameters are applied through the output interface.

  The ECU 0 of the present embodiment is configured such that when the engine speed is equal to or lower than the predetermined value and / or when the amount of decrease in the engine speed per unit time is equal to or higher than the predetermined value, the operation requests for a plurality of external loads are simultaneous When they occur continuously in time, these external loads are activated according to a predetermined priority order.

  For example, when the driver or passenger operates the operation switch to operate the air conditioner, or when the auto air conditioner ECU determines that the air conditioner should be operated and issues a signal to that effect It is required to start the compressor that compresses the refrigerant and the blower that blows air at the same time. In addition, when the driver or passenger operates the operation switch to operate both the air conditioner and the defogger, the defogger must be activated at the same time in addition to the compressor and the blower. In addition, if the cooling water temperature of the internal combustion engine is high, it is also required to cool the cooling water by rotationally driving the radiator fan. If the electrical load increases, the amount of power generated by the alternator 63 must be increased.

  In this way, it is required to operate a plurality of external loads at the same time, and as a result of simultaneously starting the plurality of external loads in response to the request, the mechanical load on the internal combustion engine (by the compressor and alternator 63) increases rapidly. As a result, the engine speed is reduced. A large drop in engine speed adversely affects drivability and drive feeling, and the possibility of engine stall cannot be denied.

  Therefore, in the present embodiment, in a situation where the problem of engine speed drop becomes apparent, that is, in a deceleration period where the engine speed is already below a predetermined value or the amount of decrease in the engine speed per unit time is a predetermined value or more. The external loads requested to be activated are sequentially activated at time intervals in accordance with the set priority order.

  As already mentioned, there are various external loads on the internal combustion engine. Among them, lighting lamps such as headlamps and blinkers, radiator fans that cool cooling water, and electric power steering devices operate immediately when there is a request to activate them for the safety of vehicle operation. Because it is a property that must be made to operate, it is operated with the highest priority (immediately upon request).

  Compared to this, it can be said that air conditioners, defoggers, audio devices, car navigation systems, etc. do not have a high priority for operation. Furthermore, the compressor, defogger, and the like of the air conditioner are low in priority because they are not easily noticed by the driver or passenger even if they are not immediately activated in response to the operation request.

Hereinafter, in order to simplify the description, among the external loads, the refrigerant compression compressor of the air conditioner, the blower for the air conditioner, and the defogger will be described in detail. The order in which it is difficult for the driver or occupant to notice without starting immediately in response to an activation request is
(First place) Compressor; if the blower is operating, the driver or passenger will recognize that the air conditioner is working for the time being (second place) Defogger; Blower that does not disappear (third place); if the blower does not operate, it is considered that the driver or passenger misunderstands that the air conditioner has failed. On the other hand, in order of increasing load on the internal combustion engine,
(1st) Compressor (2nd) Defogger (3rd) Blower.

In principle, it is preferable to set the priority when there is a request to activate a plurality of external loads in the order that the driver or the passenger is easily noticed (provides a sense of incongruity) if not activated. Further, in view of the purpose of avoiding a large drop in the engine speed, and hence engine stall, those with a smaller load on the internal combustion engine can be given higher priority. According to this principle, the priority of starting the above external load is
(1st) Blower (2nd) Defogger (3rd) Compressor.

  However, the priority of the operation of the external load is not always constant. The ECU 0 may change the priority of the operation of the external load in accordance with the amount of charge currently stored in the battery 62 or the current power generation amount of the alternator 63.

  In particular, in a situation where the charge amount of the battery 62 is relatively high or the power generation amount of the alternator 63 is relatively low, there is still room for power supply capacity, so that it is not operated regardless of the amount of power consumption. It is preferable to activate the external load in order from the one that is easily noticed by the passenger or passenger. On the other hand, in a situation where the charge amount of the battery 62 is relatively low or the power generation amount of the alternator 63 is relatively high, it is already known that the driver or the passenger feels uncomfortable because the power supply capacity is already insufficient. Thus, it is preferable to start up the external load in order of increasing power consumption.

  As a specific example, assuming that the power consumption of the audio device or the car navigation system is lower than that of the blower, and the charge amount of the battery 62 is less than a predetermined value or the power generation amount of the alternator 63 is more than a predetermined value, The audio device or the car navigation system is activated with priority, and the blower blower is activated after a while. Conversely, when the charge amount of the battery 62 is equal to or greater than the predetermined value or the power generation amount of the alternator 63 is equal to or less than the predetermined value, the blower for blower is preferentially activated, and thereafter the audio device or the car navigation system is activated.

  Note that an external load with a low priority of activation may not be activated even if there is a request to activate the external load.

  FIG. 3 shows a procedure example of processing executed by the ECU 0 when starting a plurality of external loads. When requests for operating a plurality of external loads are generated substantially simultaneously or continuously within a predetermined time (step S1), the ECU 0 determines that the engine speed at that time is less than a predetermined value and / or the engine It is determined whether or not the amount of decrease in the number of revolutions per unit time is greater than or equal to a predetermined value (step S2).

  If the current engine speed is greater than or equal to a predetermined value, or the amount of decrease in engine speed per unit time is not greater than or equal to a predetermined value (not in an apparent deceleration period), a plurality of external loads are activated as required (step S3). ).

  On the other hand, if the current engine speed is less than a predetermined value and / or the amount of decrease in the engine speed per unit time is greater than or equal to a predetermined value (in an apparent deceleration period), the battery at that time The order of priority of the operation of the plurality of external loads is determined according to the remaining amount of electricity stored 62 or the amount of power generated by the alternator 63 (step S4). However, if the priority of the operation of the external load is always constant, the step S4 is omitted.

  Then, the requested plurality of external loads are sequentially activated in accordance with the priority order determined in step S4 (step S5). In step S5, at least one external load having a low priority is reduced until the engine speed recovers to a predetermined level or more, or the amount of decrease in the engine speed per unit time is equal to or less than a predetermined value (from an apparent deceleration period). May not start up.

  In the present embodiment, the internal combustion engine and a plurality of external loads that operate using the output of the internal combustion engine are controlled, and the engine speed is equal to or lower than a predetermined value, or the amount of decrease in the engine speed per unit time. When at least one of the conditions that is equal to or greater than a predetermined condition is satisfied, when a plurality of external load operation requests are generated substantially simultaneously or continuously within a predetermined time, the external loads are activated according to a predetermined priority order. The control device 0 is characterized by the above.

  According to the present embodiment, it is possible to avoid the problem that the engine speed greatly drops when the operation of a plurality of external loads is requested at the same time. In other words, in a situation where the engine speed is low or in the deceleration period, a plurality of external loads are not activated at the same time or within a short period of time, but are sequentially activated in accordance with the priority order. Correction control (increase in intake air amount and fuel injection amount) that increases the output of the internal combustion engine in response to the operation of the load is in time, and it is possible to prevent a drop in engine speed that would cause an engine stall.

  In addition, safety is ensured by always operating external loads, such as illumination lamps and electric power steering devices, which are indispensable for the safety of vehicle driving, by operating them with the highest priority.

  In addition, the amount of charge of the battery that supplies power necessary for the operation of at least one of the external loads or the amount of power generated by the alternator is detected, and the amount of charge or the amount of power generated and the engine speed or a decrease per unit time thereof are detected. The priority order may be changed according to the amount. In other words, when there is still a margin in the power supply capacity, start the external load in order from the one that the driver or passenger is likely to notice that it is not operating, and if the power supply capacity is already insufficient, It is possible to switch control such that the external load is activated in the order of power consumption.

  The present invention is not limited to the embodiment described in detail above. The specific configuration of each part, the specific processing procedure, and the like can be variously modified without departing from the spirit of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used for controlling an internal combustion engine and auxiliary equipment mounted on a vehicle and an external load.

0 ... Control unit (ECU)
62 ... Battery 63 ... Alternator

Claims (1)

A plurality of external loads that operate using an internal combustion engine and an output of the internal combustion engine,
In the case where at least one of the conditions that the engine speed is equal to or lower than the predetermined value or the amount of decrease in the engine speed per unit time is equal to or higher than the predetermined value is satisfied,
When the operation requests of a plurality of external loads are generated substantially simultaneously or continuously within a predetermined time, the external loads are activated according to a predetermined priority order .
Detecting the amount of charge of a battery or the amount of power generated by an alternator that supplies power necessary for at least one operation of the external load;
The priority is different between a situation where the charge amount is relatively high or the power generation amount is relatively low, and a situation where the charge amount is relatively low or the power generation amount is relatively high,
When the amount of charge is relatively high or the amount of power generation is relatively low, the external load is activated in a priority order that does not depend on the magnitude of power consumption,
A control device that activates an external load in ascending order of power consumption when the charge amount is relatively low or the power generation amount is relatively high .

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