JP2015143478A - control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress or avoid the generation of a shock in a delay time after the establishment of a fuel cut condition until a start of a fuel cut or at timing immediately after the start of the fuel cut.SOLUTION: When a fuel cut condition is established, the execution of a fuel cut for stopping fuel supply to a cylinder of an internal combustion engine after the lapse of a delay time is started, and when a clutch which is interposed between the internal combustion engine and a refrigerant compressing compressor of an air conditioner is disconnected during the delay time or at the timing immediately after the start of the fuel cut, the fastening of the clutch is prohibited when a temperature of an evaporator is not higher than a prescribed temperature from a reference temperature, or the fastening of the clutch is prohibited when the temperature of the evaporator is lower than the prescribed temperature.

Description

  The present invention relates to a control device that controls a vehicle equipped with an internal combustion engine and an air conditioner for air conditioning in a vehicle interior.

  In an internal combustion engine mounted on a vehicle, it is known to perform a fuel cut that temporarily stops fuel injection in accordance with the driving situation. Normally, when the accelerator pedal depression amount is 0 or less than a threshold value close to 0 and the engine speed is equal to or higher than the fuel cut permission speed, the fuel cut is started assuming that the fuel cut condition is satisfied. Then, when any fuel cut end condition is satisfied, such as when the accelerator pedal depression amount exceeds the threshold value, or the engine speed decreases to the fuel cut return speed, the fuel cut ends and the fuel injection resumes. .

  If the fuel supply is cut off suddenly when the engine torque is relatively large, a torque shock that causes the engine speed and the vehicle speed to drop stepwise occurs, causing the passengers including the driver to feel the shock. In order to reduce this torque shock, conventionally, even if the fuel cut condition is satisfied, the fuel injection is not stopped immediately, but the fuel injection is stopped after waiting for a certain delay time (for example, (See the following patent document).

Japanese Patent Laid-Open No. 10-030477

  The internal combustion engine includes various auxiliary machines that are driven by the supply of rotational torque from the crankshaft as its output shaft, such as a generator, a cooling water pump, a lubricating oil pump, and a compressor for compressing refrigerant in an air conditioner. Accompanying.

  In general, a magnet clutch that can be connected and disconnected is interposed between a crankshaft of an internal combustion engine and a compressor. An electronic control unit that controls the operation of the internal combustion engine and the auxiliary machine engages a magnetic clutch when the air conditioner is operated, and starts compression of the refrigerant by the compressor.

  When the clutch is engaged during the delay time from when the fuel cut condition is established to when the fuel cut is started, or at the time immediately after the start of the fuel cut, a mechanical load from the compressor is applied to the internal combustion engine. As a result, the torque transmitted from the internal combustion engine to the drive system and the axle (drive wheel) is reduced, and a shock is rarely generated in the vehicle.

  The present invention has been made by paying attention to the above problems for the first time, and is intended to suppress or avoid the occurrence of shock during the delay time from the establishment of the fuel cut condition to the start of the fuel cut, or at the time immediately after the start of the fuel cut. The intended purpose.

  The present invention is a control device for controlling a vehicle equipped with an internal combustion engine and an air conditioner for vehicle interior air conditioning, and when a fuel cut condition is satisfied, after waiting for the delay time to elapse, the control device controls the vehicle. And a clutch interposed between the internal combustion engine and the refrigerant compression compressor of the air conditioner during the delay time or immediately after the start of the fuel cut. If the temperature of the evaporator or the vicinity thereof is not higher than a reference value by a predetermined value or more, the clutch is prohibited from being engaged, or if the temperature of the evaporator or the vicinity thereof is not a predetermined temperature or more, A control device for prohibiting the engagement of the clutch was configured.

  According to the present invention, it is possible to suppress or avoid the occurrence of a shock during the delay time from the establishment of the fuel cut condition to the start of the fuel cut, or at the time immediately after the start of the fuel cut.

The figure which shows schematic structure of the internal combustion engine and control apparatus in one Embodiment of this invention. The figure which shows the structure of the vehicle air conditioner in the embodiment. The figure which shows the electric circuit for controlling the various electric loads mounted in the vehicle. The timing diagram which shows the pattern of the control which the control apparatus of the embodiment performs. The timing diagram which shows the pattern of the control which the control apparatus of 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. The internal combustion engine in the present embodiment is a spark ignition type 4-stroke gasoline engine, and includes a plurality of cylinders 1 (one of which is shown in FIG. 1). In the vicinity of the intake port of each cylinder 1, an injector 11 for injecting fuel is provided. A spark plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1. The spark plug 12 receives spark voltage generated by the ignition coil and causes spark discharge between the center electrode and the ground electrode. The ignition coil is integrally incorporated in a coil case together with an igniter that is a semiconductor switching element.

  The intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1. On the intake passage 3, an air cleaner 31, an electronic throttle valve 32, a surge tank 33, and an intake manifold 34 are arranged in this order from the upstream.

  The exhaust passage 4 for discharging the exhaust guides the exhaust generated as a result of burning the fuel in the cylinder 1 from the exhaust port of each cylinder 1 to the outside. An exhaust manifold 42 and an exhaust purification three-way catalyst 41 are disposed on the exhaust passage 4.

  FIG. 2 shows a configuration of an air conditioner 5 that performs air conditioning in a vehicle interior. The air conditioner 5 includes a compressor 51 for compressing and increasing the pressure of the refrigerant, a capacitor 52 for dissipating and liquefying the compressed high-pressure refrigerant, a capacitor fan 53 for forcibly cooling the capacitor 52, and no liquefaction. Receiver 54 for separating the gaseous refrigerant from the liquefied refrigerant, an expansion valve 55 for ejecting the liquefied refrigerant, an evaporator 56 for receiving the ejected and vaporized refrigerant and exchanging heat with the air in the room, and a high-temperature internal combustion engine The heater core 59 that receives the cooling water from the interior and exchanges heat with the indoor air, the blower fan 57 that sucks the indoor air, discharges it toward the evaporator 56, and sends the air into the room again, and the evaporator 56 discharged from the blower fan 57 To adjust how much air passed through the heater core 59 is blown And a mix damper 50 as an element. The compressor 51, the condenser 52, the receiver 54, the expansion valve 55, and the evaporator 56 are connected by a refrigerant flow path that loops.

  The compressor 51 is a kind of auxiliary equipment that accompanies the internal combustion engine. The compressor 51 receives rotational torque from the crankshaft of the internal combustion engine and is rotationally driven to compress the refrigerant. Between the crankshaft and the compressor 51, there is a magnet clutch 61 capable of switching between connection and disconnection.

  The condenser 52 is disposed at a portion where the traveling wind hits in the engine room of the vehicle, and is cooled by the traveling wind blown into the engine room during traveling of the vehicle regardless of whether the condenser fan 53 is rotated. Behind the condenser 52 is a radiator 7 for radiating the cooling water of the internal combustion engine. The radiator 7 is also cooled by the traveling wind.

  The condenser fan 53 also serves as a radiator fan for forcibly cooling the radiator 7 for radiating the cooling water of the internal combustion engine. The condenser fan / radiator fan 53 is located behind the radiator 7 and cools both the condenser 52 and the radiator 7 by sucking air from the front and discharging it to the rear.

  When the air discharged from the blower fan 57 passes through the evaporator 56, it obtains cold heat from the refrigerant (heat is taken away by the refrigerant) and decreases in temperature. At the same time, the water vapor contained in the air condenses and adheres to the evaporator 56, and the humidity decreases. The evaporator 56 plays a role not only for cooling the room temperature in the summer but also for reducing the fog on the window glass of the vehicle by reducing the room humidity in the winter.

  The air mix damper 50 adjusts the ratio of the amount of air that passes through the heater core 59 and goes into the room, and the amount of air that goes around the heater core 59 and goes into the room among the air that has passed through the evaporator 56. The air mix damper 50 can adjust the temperature of the air blown into the room.

  A fan motor 531 serving as a drive source for the condenser fan / radiator fan 53, a fan motor 571 serving as a drive source for the blower fan 57, a magnet clutch 61 for fastening the crankshaft of the internal combustion engine and the compressor 51, and other electric loads. The power source for operating is a vehicle-mounted battery 62 and a generator (alternator or motor generator) 63.

  FIG. 3 shows an electric circuit for controlling various electric loads mounted on the vehicle. When the compressor 51 of the air conditioner 5 is operated, the magnet clutch 61 is energized with current from the on-board battery 62 and / or the generator 63 and the magnet clutch 61 is fastened. On the contrary, when the compressor 51 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 blower fan 57 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 generator 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.

  A generator 63, which is a source of power supply to the electric load, is rotationally driven in response to transmission of rotational driving force from the crankshaft of the internal combustion engine to generate electric power. The generator 63 is connected to the crankshaft via a winding transmission mechanism having a belt and a pulley as elements. The generator 63 may perform regenerative power generation. In other words, when the driver does not step on the accelerator pedal and does not require acceleration of the vehicle (accepts deceleration), the energy of rotation of the crankshaft and axle is converted into electric energy and recovered. , Decelerate the internal combustion engine and the vehicle.

  The magnitude of the voltage generated and output by the generator 63 can be controlled via the regulator 65. The regulator 65 is a known IC type attached to the generator 63, and performs a switching operation for switching ON / OFF the energization of the field coil of the generator 63.

  The output voltage of the generator 63, that is, the voltage induced in the stator coil of the generator 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 the output voltage of the generator 63 from the ECU 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 generator 63 can be increased or decreased. The amount of power generated by the generator 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.

  The ECU 0 as the control device for the internal combustion engine of the present embodiment 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, a crank angle 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 a sensor that detects the amount or the opening of the throttle valve 32 as an accelerator opening (so-called required load), the intake air temperature and the intake pressure in the intake passage 3 (particularly, the surge tank 33). The intake air temperature / intake pressure signal d output from the temperature / pressure sensor to be detected, the outside air temperature signal e output from the outside air temperature sensor that detects the outside air temperature, and the water temperature output from the water temperature sensor that detects the cooling water temperature of the internal combustion engine. Refrigerant pressure output from a refrigerant pressure sensor that detects the signal f, the pressure of the refrigerant flowing down from the condenser 52 of the air conditioner 5 No. g, the evaporator 56 or the evaporator temperature signal h or the like to be outputted from the temperature sensor to detect the proximity or the temperature of the downstream is input.

  From the output interface, an ignition signal i for the igniter of the spark plug 12, a fuel injection signal j for the injector 11, an opening operation signal k for the throttle valve 32, and an electric circuit switch for energizing the magnet clutch 61 64, the clutch engagement signal o, the motor 66, the heater 68, and other switches 67, 69 on the electric circuit for energizing the electric load, the switch ON signals p, q, the voltage for controlling the voltage generated by the generator 63. A voltage instruction signal r or the like is output to the regulator 65.

  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 the 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, the compressor 51 of the air conditioner 5 Various operation parameters such as ON / OFF, output voltage (power generation amount) of the generator 63, and the like are determined. The ECU 0 applies various control signals i, j, k, o, p, q, r corresponding to the operation parameters via the output interface.

  In the present embodiment, the ECU 0 receives a command to activate the air conditioner 5 by the driver, and in a situation where the compressor 51 is to be operated and the refrigerant is to be compressed, the magnet clutch 61 is engaged and the internal combustion engine The crankshaft and the compressor 51 are connected. The situation in which the compressor 51 should be operated is, for example, when the evaporator temperature obtained by referring to the evaporator temperature signal h is higher than a predetermined operating condition temperature.

  In turn, in a situation where the compressor 51 should be stopped, the engagement of the magnet clutch 61 is released and the crankshaft of the internal combustion engine and the compressor 51 are disconnected. The situation where the compressor 51 should be stopped is, for example, when the evaporator temperature is higher than a predetermined stop condition temperature. The value of the stop condition temperature is slightly lower (for example, about 1 ° C. to 2 ° C.) than the value of the operating condition temperature.

  Moreover, ECU0 of this embodiment performs the fuel cut which stops fuel injection from the injector 11 temporarily according to a driving | running state. Normally, it is assumed that the fuel cut condition is satisfied when the accelerator pedal depression amount is 0 or less than a threshold value close to 0 and the engine speed is equal to or higher than the fuel cut permission speed.

  However, even if the combustion cut condition is satisfied, the fuel cut is not started immediately. When the fuel cut condition is satisfied, the ECU 0 stops the fuel injection only after waiting for the delay time to reduce the engine torque to the target torque. During this delay time, the opening degree of the throttle valve 32 is close to 0, and the intake air amount and the fuel injection amount charged into the cylinder 1 are small. In addition, during the delay time, the spark ignition timing in the spark plug 12 is positively retarded to promote a decrease in engine torque.

  The current engine torque can be estimated based on the engine speed, the intake pressure in the surge tank 33 and the intake air temperature (or the intake air amount filled in the cylinder 1), the ignition timing, and the like. In the memory of the ECU 0, map data that defines the relationship between the engine speed, the intake pressure and intake temperature, the ignition timing, and the engine torque is stored in advance. The ECU 0 searches the map using the current engine speed, intake pressure and intake temperature, ignition timing, etc. as keys, and obtains the current estimated engine torque.

The target torque is the amount of torque reduction corresponding to the deceleration of the vehicle speed that does not cause the driver or passenger to feel an impact;
Torque reduction amount = allowable deceleration × (vehicle weight + passenger weight) ÷ transmission efficiency × wheel (tire) diameter ÷ transmission gear ratio ÷ differential ratio. The allowable deceleration is 0.08G, for example. The crew weight is, for example, 60 kg multiplied by the assumed number of people. If mainly two passengers are assumed, the crew weight is 120 kg. The transmission efficiency is the overall transmission efficiency of a drive system (for example, a torque converter, a forward / reverse switching device, a transmission, and a differential device) and wheels, for example, 0.9. The gear ratio of the transmission is a value corresponding to the gear ratio and shift position when the fuel cut condition is satisfied.

The target torque is the maximum value allowed for a decrease in engine torque due to fuel cut, that is, stop of fuel injection;
Target torque = torque reduction amount−defined by the mechanical loss of the internal combustion engine and auxiliary equipment after the fuel cut condition is satisfied. The term of mechanical loss in the decrease in engine torque due to the fuel cut includes the engine speed and engine cooling temperature after the fuel cut condition is satisfied, the operating status of the refrigerant compression compressor 51, and the generator 63 The value depends on the amount of power generation. The term of mechanical loss increases as the engine speed increases, and increases as the cooling water temperature decreases. In particular, the cooling water temperature suggests friction in various parts of the engine. The lower the coolant temperature, the lower the engine temperature, the higher the viscosity of the lubricating oil, and the greater the friction.

  Therefore, in the present embodiment, when the clutch 61 is disengaged at the time when the fuel cut condition is satisfied and the compressor 51 is not operating, the compressor 51 during the subsequent delay time or immediately after the start of the fuel cut. Even if it is the situation which should operate | move, it is supposed that the fastening of the clutch 61 will be restrict | limited.

  Specifically, if the evaporator temperature is not higher than a predetermined value from the reference temperature during the delay time or immediately after the start of fuel cut execution, even if the evaporator temperature is higher than the above operating condition temperature, the clutch The fastening of 61 is prohibited. The reference temperature mentioned here is the evaporator temperature at the time when the compressor 51 is stopped most recently. The reference temperature is basically equal to the above stop temperature condition, but may be a different temperature. The predetermined value is set to a value (for example, 4 ° C.) larger than the difference between the operating condition temperature and the stop condition temperature. That is, the temperature obtained by adding a predetermined value to the reference temperature is higher than the normal operating condition temperature.

  The reason why the clutch 61 is not engaged when the evaporator temperature is not higher than the reference temperature is that the evaporator temperature is still low, and if the evaporator temperature is short, the necessary and sufficient air conditioning (cooling) performance can be provided without operating the refrigerant circuit. It depends on what is considered.

FIG. 4 shows a control pattern by the ECU 0 of the present embodiment. If the clutch 61 is not engaged at the time point t ₀ when the fuel cut condition is satisfied, the clutch 61 is not re-engaged even if the evaporator temperature becomes equal to or higher than the operating condition temperature. The clutch 61 is engaged for a certain period of time from the time t ₃ (represented by a broken line in FIG. 4) when the evaporator temperature becomes higher than a predetermined value from the reference temperature (stop condition temperature) or from the time t ₁ when the fuel cut is started. there is the time t ₂ later elapsed (in FIG. 4, represented by the solid line. of course, it is assumed the evaporator temperature is operating conditions temperature or higher). From time t ₀ to time t ₁ is a delay time before the start of fuel cut, and from time t ₀ to time t ₂ is a time limit for restricting engagement of the clutch 61.

  In addition, when the clutch 61 is engaged and the compressor 51 is operating when the fuel cut condition is satisfied, the compressor 51 should be stopped during the subsequent delay time or immediately after the start of the fuel cut. Even if there is, the disconnection of the clutch 61 is limited.

FIG. 5 shows a pattern of control by the ECU 0 of the present embodiment. When the clutch 61 is engaged at the time point t ₀ when the fuel cut condition is satisfied, the clutch 61 is not disconnected even if the evaporator temperature becomes equal to or lower than the stop condition temperature. The clutch 61 is disengaged after a time t ₄ when a predetermined time has elapsed from the time t ₁ when the fuel cut is started. The time from the time point t ₀ to the time point t ₄ is a time limit for limiting the disengagement of the clutch 61. Note that the time point t ₄ may be the same time point as the time point t ₂ shown in FIG. 4 or a different time point.

  In this embodiment, the control device 0 controls a vehicle equipped with an internal combustion engine and an air conditioner 5 for air conditioning in the vehicle interior, and when the fuel cut condition is satisfied, the internal combustion engine waits for the delay time to elapse. The fuel cut for stopping the fuel supply to the cylinder 1 is started. During the delay time or immediately after the start of the fuel cut, the refrigerant compression compressor 51 of the internal combustion engine and the air conditioner 5 When the clutch 61 interposed therebetween is disengaged, the control device 0 is configured to prohibit the engagement of the clutch 61 when the temperature of the evaporator 56 or the vicinity thereof is not higher than the reference temperature by a predetermined value or more.

  According to this embodiment, the torque transmitted from the internal combustion engine to the drive system and the axle is reduced due to the compressor 51 starting to operate during the delay time before the start of the fuel cut condition or immediately after the start of the fuel cut. The problem of shock in the vehicle can be suppressed or avoided.

  In the present embodiment, when the clutch 61 interposed between the internal combustion engine and the refrigerant compression compressor 51 of the air conditioner 5 is engaged during the delay time or immediately after the start of the fuel cut. The clutch 61 is prohibited from being disconnected. As a result, the torque transmitted from the internal combustion engine to the drive system and the axle due to the stop of the compressor 51 during the delay time or immediately after the start of fuel cut increases, and the vehicle feels as if it jumps forward. Can be suppressed or avoided for the driver and the passenger.

  The present invention is not limited to the embodiment described in detail above. For example, in the above-described embodiment, the clutch that has been disconnected when the temperature of the evaporator 56 or its vicinity is not higher than a predetermined value from the reference temperature during the delay time before the start of the fuel cut or immediately after the start of the fuel cut execution. Although the fastening of 61 is prohibited, the fastening of the clutch 61 may be prohibited when the temperature of the evaporator 56 or the vicinity thereof is not higher than a predetermined temperature. The predetermined temperature mentioned here is a temperature value higher than the above operating condition temperature.

  Other specific configurations of each part can be variously modified without departing from the spirit of the present invention.

  The present invention can be applied to control of an internal combustion engine and an air conditioner mounted on a vehicle.

0 ... Control unit (ECU)
DESCRIPTION OF SYMBOLS 1 ... Cylinder 11 ... Injector 5 ... Air conditioner 51 ... Refrigerant compression compressor 56 ... Evaporator 61 ... Clutch

Claims (1)

A control device for controlling a vehicle equipped with an internal combustion engine and an air conditioner for air conditioning in a vehicle interior,
When the fuel cut condition is satisfied, the execution of the fuel cut for stopping the fuel supply to the cylinder of the internal combustion engine is started after waiting for the delay time to elapse.
When the clutch interposed between the internal combustion engine and the refrigerant compression compressor of the air conditioner is disengaged during the delay time or immediately after the start of the fuel cut, the temperature of the evaporator or the vicinity thereof is the reference temperature. A control device that prohibits the engagement of the clutch if it is not higher than a predetermined value from the above, or prohibits the engagement of the clutch if the temperature of the evaporator or its vicinity is not higher than the predetermined temperature.

Images