JP5757846B2 - Control device - Google Patents

Description

  The present invention relates to rotation control of a fan that cools a condenser of a radiator or an air conditioner associated with an internal combustion engine.

  There are two types of cooling methods for internal combustion engines mounted on vehicles: air-cooled and water-cooled, but in the case of water-cooled, the cooling air radiates and heats the cooling water by applying airflow from the running wind or fan to the radiator through which the cooling water flows. I'm trying to descend. The radiator fan is activated, for example, when the cooling water temperature being sensed is equal to or higher than a predetermined threshold value. That is, the relay switch provided on the electric circuit connecting the battery and the generator (alternator) and the fan motor is turned on to energize the fan motor and drive the fan to rotate (for example, refer to the following patent document). . The radiator fan is also used for cooling the refrigerant flowing through the condenser of the air conditioner housed in the same engine room.

  When the relay is turned on and the fan motor is energized, the fan motor and the fan start to rotate rapidly. As the rotation of the fan starts, the noise may feel suddenly rising. In particular, when the vehicle is stopped and the running wind does not flow into the engine room and the cooling water temperature rises and the radiator fan starts up, a large fan drive sound may sound in a relatively quiet vehicle interior. It was inconvenient.

Japanese Patent Laid-Open No. 06-299852

  An object of the present invention is to effectively reduce the noise problem associated with starting a fan that cools a radiator or a condenser.

  In the present invention, in controlling the rotation of a fan for cooling a condenser of an internal combustion engine or a condenser of an air conditioner, power is supplied to the fan motor from both the battery and the generator to drive the fan. When starting the fan on the condition that a predetermined fan drive condition has been established, the power generation voltage of the generator is lowered and then the power is supplied to the fan motor to rotate the fan. It was decided to raise.

  Here, as a specific example of the fan driving condition, a magnet clutch interposed between the crankshaft of the internal combustion engine and the compressor of the air conditioner when the temperature of the fluid flowing through the radiator or the condenser exceeds a predetermined threshold value When the air conditioner is engaged (the air conditioner is turned on), the abnormality of the sensor is detected by the diagnosis of the cooling water temperature sensor, and the like.

  ADVANTAGE OF THE INVENTION According to this invention, the problem of the noise accompanying the starting of the fan which cools a radiator or a capacitor | condenser can be reduced effectively.

The figure which shows the whole structure of the internal combustion engine in one Embodiment of this invention. The circuit diagram which shows the electric power feeding circuit and control apparatus to a fan motor in the embodiment. The timing diagram which shows the example of control of the radiator fan in the embodiment. The timing diagram which shows the example of control of the radiator fan in the embodiment.

  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 gas from 4 toward 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.

  An ECU (Electronic Control Unit) 0 that is a control device for an internal combustion engine 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 for detecting the vehicle speed, an engine rotation signal b output from an engine rotation sensor for detecting the rotation angle and engine speed of the crankshaft, an accelerator pedal depression amount or a throttle. An accelerator opening signal c output from an accelerator opening sensor that detects the opening of the valve 33 as an accelerator opening (so-called required load), an intake air temperature and an intake pressure in the intake passage 3 (especially, the surge tank 34). An intake air temperature / intake pressure signal d output from a temperature / pressure sensor to be detected, a cooling water temperature signal e output from a water temperature sensor to detect a cooling water temperature of the internal combustion engine, and a cam angle sensor based on a plurality of cam angles of the intake camshaft The cam signal f output from the vehicle, the operation signal g regarding whether or not the air conditioner is operating, the vehicle-mounted battery 61 Battery state signal h or the like to be output from the sensor for detecting an index indicative of state of charge is input. The operation signal g of the air conditioner may be a signal issued from a switch manually operated by the driver to turn on the air conditioner or a signal issued from an auto air conditioner ECU that controls the auto air conditioner system. . The battery status signal h displays, for example, battery current, battery voltage, and battery temperature.

  From the output interface, the fuel injection signal h for the injector 11, the ignition signal i for the ignition plug (ignition coil thereof), the opening operation signal j for the EGR valve 22, and the opening operation for the throttle valve 33. The signal k, the opening operation signal l for the waste gate valve 44, the start signal m for the relay switch 63 on the electric circuit for energizing the fan motor 64 for rotating the radiator fan, and the generator (alternator) 62 generate power. A voltage instruction signal n or the like is output to a voltage regulator 621 that controls the voltage.

  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, and g necessary for operation control of the internal combustion engine via the input interface, knows the engine speed, and fills the cylinder 1 with the intake air amount. Is estimated. 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) And various operating parameters such as the opening degree of the EGR valve 22, ON / OFF of the radiator fan, and the generated voltage of the generator 62 are determined. As the operation parameter determination method itself, a known method can be adopted, and the description thereof will be omitted. Thus, various control signals h, i, j, k, l, m, and n corresponding to the operation parameters are applied through the output interface.

  A radiator (not shown) associated with the internal combustion engine and a condenser (not shown) of an air conditioner are housed in the engine room of the vehicle and can be air-cooled by running wind blown into the engine room. In addition, an electric radiator fan is installed near the radiator or condenser. When the temperature of engine coolant or air conditioner refrigerant rises, the fan is driven as necessary, and the air flow generated by the fan is It is sprayed on the condenser and the heat dissipation effect in the radiator and condenser is promoted.

  As shown in FIG. 2, the fan motor 64 that rotationally drives the radiator fan is electrically connected to both the battery 61 and the generator 62 and can receive power supply from both the battery 61 and the generator 62.

  The generator 62 generates electric power by receiving a rotational driving force from the crankshaft of the internal combustion engine. A magnet clutch (not shown) capable of switching between connection and disconnection is interposed between the crankshaft and the generator 62. The ECU 0 (or the automatic air conditioner ECU) energizes the magnet clutch when the amount of charge of the battery 61 decreases or when the power demand required by the air conditioner, the lighting lamp, or other auxiliary equipment increases, And the driving force is transmitted to the generator 62 from the crankshaft. Conversely, when the amount of charge of the battery 61 is sufficiently high and the power demand required by the auxiliary equipment is low, the magnet clutch is cut off and the clutch is disconnected to reduce the load on the internal combustion engine and reduce the fuel consumption. To improve.

  The generator 62 includes a voltage regulator (IC regulator) 621 similar to that known. The voltage regulator 621 is an element that adjusts the magnitude of the voltage generated by the generator 62. The ECU 0 transmits a signal n that commands the generated voltage to the voltage regulator 621. The voltage regulator 621 that has received this signal intermittently controls the current flowing through the rotor coil of the generator 62 so that the output voltage of the generator 62 matches the command value from the ECU 0. The output voltage of the generator 62 is determined according to the operating range (engine speed and / or required load) of the internal combustion engine and the charge amount of the battery 61.

The ECU 0 energizes the fan motor 64 and starts the radiator fan on condition that a predetermined fan driving condition is satisfied. The fan driving condition includes at least one of the following.
The engine speed is higher than a predetermined value and the cooling water temperature of the internal combustion engine is higher than a predetermined threshold value. The water temperature sensor for detecting the cooling water temperature is abnormal or malfunctioning. The air conditioner is operating. That is, the magnet clutch interposed between the crankshaft and the compressor is fastened. In this embodiment, however, when the fan motor 64 is energized to start the fan, the power generation voltage of the generator 62 is temporarily set. Control is performed to lower the voltage and then increase the power generation voltage again.

  FIG. 3 is an example of control by the ECU 0. In the example shown in FIG. 3, when the cooling water temperature becomes equal to or higher than the threshold value KFANON, the ECU 0 switches the relay switch 63 to ON to energize the fan motor 64, while when the cooling water temperature becomes lower than the threshold value KFANOFF, the ECU 0 The switch 63 is turned off to cut off the energization to the fan motor 64.

  Then, when the relay switch 63 is turned on, the value of the generated voltage commanded from the ECU 0 to the voltage regulator 621 is set to a value once lower than the value determined in accordance with the operating range of the internal combustion engine and the charge amount of the battery 61. To do. Thereafter, the value of the generated voltage commanded to the voltage regulator 621 is gradually brought closer to the original value determined in accordance with the operating range of the internal combustion engine and the charge amount of the battery 61.

  FIG. 4 is another example of control by the ECU 0. Also in the example shown in FIG. 4, when the coolant temperature becomes equal to or higher than the threshold value KFANON, the ECU 0 switches the relay switch 63 to ON to energize the fan motor 64, and when the coolant temperature becomes equal to or lower than the threshold value KFANOFF, the ECU 0 63 is switched off to cut off the energization of the fan motor 64.

  In the example shown in FIG. 4, when the cooling water temperature is equal to or lower than the threshold value KFANON, the fan motor 64 is not energized. The battery voltage indicates a value (for example, about 14 V) according to the amount of charge at that time. When the cooling water temperature rises and becomes equal to or higher than the threshold value KFANON, energization to the fan motor 64 is started and a battery voltage drop occurs (for example, about 13 V). At this time, the power generation voltage commanded from the ECU 0 to the voltage regulator 621 is intentionally set to a low value equal to or lower than the battery voltage. Thereby, the voltage applied to the fan motor 64 becomes a battery voltage, and the fan motor 64 and the fan rotate at a relatively low rotational speed. Since the rotation is gentle, noise generated from the fan motor 64 and the fan is also gentle.

  Thereafter, when the heat generation of the internal combustion engine is larger than the heat dissipation of the radiator, the cooling water temperature continues to rise. However, after starting to turn the radiator fan, the temperature rises more slowly than before.

  When the cooling water temperature becomes equal to or higher than the higher threshold value KFANON +, the power generation voltage commanded from the ECU 0 to the voltage regulator 621 is gradually raised toward a higher value (for example, about 14.5 V) exceeding the battery voltage. As a result, a voltage higher than the battery voltage is applied to the fan motor 64, and the fan motor 64 and the fan rotate at a relatively high rotational speed. Therefore, the heat dissipation effect in the radiator is further increased, and the cooling water temperature is increased. It is suppressed.

  When the magnet clutch that connects the crankshaft and the compressor of the air conditioner is engaged, the ECU 0 switches the relay switch 63 to ON to energize the fan motor 64, and the magnet clutch is disconnected (freezing prevention thermistor). ECU0 is connected to the relay switch when it is determined that the temperature of the refrigerant has sufficiently decreased (such as when a predetermined time has elapsed since the fan was started). 63 may be switched off to cut off the energization of the fan motor 64. Also in this case, when the relay switch 63 is turned ON, the value of the generated voltage commanded to the voltage regulator 621 is once set to a low value less than the battery voltage, and the magnet clutch is not disengaged even if a certain amount of time passes thereafter. If the temperature of the refrigerant does not decrease, the value of the power generation voltage commanded to the voltage regulator 621 is gradually raised toward a higher value exceeding the battery voltage.

  According to this embodiment, the control device 0 controls the rotation of a fan that cools a condenser of a radiator or an air conditioner associated with an internal combustion engine, and power is supplied to the fan motor 64 from both the battery 61 and the generator 62. In order to start the fan on condition that a predetermined fan driving condition is satisfied, the power generation voltage of the generator 62 is once lowered and power is supplied to the fan motor 64. Since the control device 0 is configured to rotate the fan and then increase the power generation voltage of the generator 62 again, the rise of noise accompanying the rotational drive of the fan becomes gentle, and the noise level felt by the driver and other passengers is effective. Is suppressed.

  The control of the present embodiment can be executed by using the ECU 0, the relay switch 63, and the voltage regulator 621 that are generally mounted in existing vehicles. Therefore, it is not necessary to incorporate a separate control circuit or the like, and can be realized at a low cost.

  The present invention is not limited to the embodiment described in detail above. If the fan being controlled blows airflow to the condenser of the air conditioner and the temperature of the refrigerant flowing through the condenser can be sensed, the fan is started when the refrigerant temperature exceeds the threshold. When starting up, it is possible to perform control to once lower the power generation voltage of the generator 62, supply power to the fan motor 64 to rotate the fan, and then increase the power generation voltage of the power generator 62 again.

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

  The present invention can be used for controlling a radiator fan attached to an internal combustion engine mounted on a vehicle or the like.

0 ... Control unit (ECU)
61 ... Battery 62 ... Generator 64 ... Fan motor

Claims (1)

A control device that controls the rotation of a fan that cools a condenser of a radiator or an air conditioner associated with an internal combustion engine,
Power is supplied to the fan motor from both the battery and the generator to drive the fan.
When starting the fan on the condition that a predetermined fan drive condition has been established, the power generation voltage of the generator is lowered and then the power is supplied to the fan motor to rotate the fan. A control device characterized by being raised.

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