JP2013014155A - Clutch protection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clutch protection device capable of suppressing an increase of clutch capacity.SOLUTION: In a state that power is transmitted between a crankshaft 30 and a motor generator 14 for an auxiliary machinery via a clutch 38 and the motor generator 14 for the auxiliary machinery is driven by power supplied from an engine 16, when it is determined that a sum of torques of the motor generator 14 for the auxiliary machinery and a compressor 42 (a sum of load torques) exceeds an upper limit torque, a torque limiting process is performed. In particular, as the torque limiting process, a load torque of the motor generator 14 for the auxiliary machinery is limited by energization operation of an inverter 40 for an auxiliary machinery so that the sum of the load torques is limited to the upper limit torque or less.

Description

  The present invention relates to a clutch protection device applied to a system including an engine, a device driven by using the engine as a power supply source, and a clutch capable of adjusting a power transmission state between the engine and the device.

  2. Description of the Related Art Conventionally, a system including an engine, a device driven by using the engine as a power supply source, and a clutch capable of adjusting a power transmission state between the engine and the device is known. Here, with the start of engine combustion control, it is known that engine torque fluctuations occur due to changes in the pressure of the combustion chamber of the engine due to intake, compression, expansion, and exhaust (for example, the following patent document) 1).

Japanese Patent No. 4573298

  By the way, when the power between the device and the engine is transmitted by the clutch, when the load torque of the device increases for some reason and the engine operating point shifts to an operating point where the engine torque fluctuation is large, it is input to the clutch. Torque may exceed the maximum torque (clutch capacity) that can be transmitted by the clutch. In this case, there is a possibility that the reliability of the clutch may be lowered, for example, a seizure of the clutch may occur due to a phenomenon (slip phenomenon) in which the rotational speed on the input side of the clutch exceeds the rotational speed on the output side.

  As a method for solving such a problem, for example, increasing the clutch capacity can be cited. However, in this case, there is a concern that the size and cost of the clutch will increase.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a clutch protection device capable of suppressing an increase in clutch capacity.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  The invention according to claim 1 is an electronically controlled device capable of adjusting its own load torque, an engine mechanically connected to the device and serving as a power supply source for the device, the engine and the device. The present invention is applied to a system including a clutch that transmits or interrupts power between the engine and the power between the engine and the device is transmitted by the clutch, and the device is driven by using the engine as a power supply source. Therefore, based on the fact that the torque input to the clutch exceeds the specified torque, the load torque of the device is reduced by energizing the device to limit the torque input to the clutch below the specified torque. Torque limiting means for performing a limiting process is provided.

  In the above invention, in a situation where the load torque of the device increases due to some factor, the device is energized to limit the torque input to the clutch below the specified torque based on the fact that the torque input to the clutch exceeds the specified torque. Operate to limit the load torque of the equipment. As a result, an increase in input torque to the clutch can be suppressed, and as a result, an increase in clutch capacity can be suppressed.

  In addition, in the said invention, when the said apparatus is provided with two or more in the said system, the load torque of an apparatus means the total value of the load torque of the apparatus actually driven by using an engine as a power supply source, for example.

  According to a second aspect of the present invention, in the first aspect of the present invention, the combustion control means for controlling the combustion of the engine so that the engine generates the power required for driving the device, and the combustion control means In a situation where combustion control is performed, load torque adjusting means for adjusting the load torque of the device is further provided to control the engine speed to the target value, and during one engine combustion cycle for each engine speed. The maximum value of all the generated speeds of all the rotational speeds is defined as the maximum generated torque, and the target value is set on the higher rotation side than the engine speed corresponding to the maximum generated torque. The torque is set to a value smaller than the maximum generated torque.

  In the above invention, from the viewpoint of securing the power required for driving the device and avoiding an increase in clutch capacity, the engine speed is set higher than the engine speed corresponding to the maximum generated torque. The target value is set. In a situation where engine combustion control is performed, the load torque of the device is adjusted to control the engine speed to the target value.

  In such a configuration, when the load torque of the device increases due to some factor, the rotational speed of the engine mechanically connected to the device decreases toward the engine rotational speed side corresponding to the maximum generated torque, and the generated torque of the engine decreases. Will increase. That is, when the engine rotation speed is shifted to a rotation speed region where the engine torque fluctuation is large, the input torque to the clutch increases.

  Here, in the said invention, the said prescription | regulation torque is set to the value smaller than the maximum production | generation torque. For this reason, it is possible for the torque limiting means to suppress the load torque of the device from increasing due to some factor and shifting the engine rotational speed to the rotational speed region where the engine torque fluctuation is large. Thereby, the increase in the input torque to the clutch can be suitably suppressed.

  According to a third aspect of the present invention, there is provided an engine, a device mechanically coupled to the engine and driven by the engine as a power supply source, and an energization operation for adjusting a transmission torque between the engine and the device. And a combustion control means for controlling the combustion of the engine so as to cause the engine to generate the power required for driving the device, and between the engine and the device by the clutch. Load torque adjusting means for adjusting the load torque of the device so as to control the engine rotation speed to the target value in a state where power is transmitted and the combustion control is performed by the combustion control means; Under the situation where the load torque of the device is adjusted by the load torque adjusting means, the torque input to the clutch is a specified torque. A torque limiting means for performing a process of reducing the transmission torque by energizing the clutch so that the transmission torque of the clutch is less than or equal to the specified torque. The maximum value of all the rotational speeds among the maximum values of the generated torque during one combustion cycle is defined as the maximum generated torque, and the target value is set on the higher rotation side than the engine speed corresponding to the maximum generated torque. The prescribed torque is set to a value smaller than the maximum generated torque.

  In the above invention, from the viewpoint of securing the power required for driving the device and avoiding an increase in clutch capacity, the engine speed is set higher than the engine speed corresponding to the maximum generated torque. The target value is set. In a situation where engine combustion control is performed, the load torque of the device is adjusted to control the engine speed to the target value.

  In such a configuration, when the load torque of the device increases due to some factor, the rotational speed of the engine mechanically connected to the device decreases toward the engine rotational speed side corresponding to the maximum generated torque, and the generated torque of the engine decreases. Will increase. That is, when the engine rotation speed is shifted to a rotation speed region where the engine torque fluctuation is large, the input torque to the clutch increases.

  Here, in the above invention, based on the fact that the torque input to the clutch exceeds the specified torque smaller than the maximum generated torque, the clutch transmission torque is reduced by energizing the clutch so that the clutch transmission torque is less than the specified torque. Process to reduce. According to this process, the engine rotation speed is increased toward the target value, and the generated torque of the engine is decreased. That is, an increase in input torque to the clutch can be suitably suppressed.

  In addition, in the said invention, when the said apparatus is provided with two or more in the said system, the load torque of an apparatus means the total value of the load torque of the apparatus actually driven by using an engine as a power supply source, for example.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the device includes a rotating machine having a function of giving an initial rotation to an output shaft of the engine. When it is determined that an engine start instruction has been issued, the output of the output by the clutch is performed with the rotation of both the rotating machine and the output shaft stopped before the initial rotation is applied to the output shaft by the rotating machine. It is further characterized by further comprising a start time processing means for causing the power between the shaft and the rotating machine to be in a transmission state.

  When the initial rotation is applied to the output shaft to start the engine, the higher the rotational speed of the rotating machine with respect to the engine rotational speed (the rotational speed of the output shaft), the more power is transmitted between the output shaft and the rotating machine by the clutch. There is a tendency for the degree of increase in the input torque to the clutch to increase in the state.

  In this regard, in the above invention, the power between the rotating machine and the output shaft is transmitted by the clutch while the rotation of both the rotating machine and the output shaft is stopped. For this reason, it is possible to avoid an increase in the input torque to the clutch when the engine is started.

  According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the maximum value of all the rotational speeds among the maximum values of the generated torque during one combustion cycle of the engine at each engine rotational speed is defined as the maximum generated torque. The start time processing means increases the engine rotation speed by applying the initial rotation to a rotation speed higher than the engine rotation speed corresponding to the maximum generated torque, and then starts combustion control of the engine. And

  As engine characteristics, the engine torque fluctuation generally tends to decrease as the engine rotation speed increases at a higher rotation speed than the rotation speed corresponding to the maximum generated torque. Here, in the said invention, combustion control of an engine is started in the high rotation side rather than the said maximum production | generation torque. That is, the engine is driven while avoiding a rotation region where the torque fluctuation of the engine is large. For this reason, the increase in the vibration accompanying the drive of an engine can be suppressed suitably.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the device includes a rotating machine, and the torque limiting means is based on a current flowing through the rotating machine. It is determined whether the torque input to the clutch exceeds the specified torque.

  In the said invention, it can be determined appropriately whether the torque input into a clutch from an apparatus becomes more than specified torque based on the electric current which flows into a rotary machine.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, characterized in that the device includes a rotating machine and a compressor for air conditioning.

  In the above invention, the system is provided with the rotating machine and the compressor for the purpose of power generation and air conditioning. Here, in the above system, for example, the load torque of the compressor may change due to the change of the heat exchange state in the heat exchanger of the refrigeration cycle, and the input torque to the clutch may increase.

  The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein the engine is a single cylinder engine.

1 is a system configuration diagram according to a first embodiment. FIG. The figure which shows the structure of a power generation air conditioning unit. The figure which shows the outline | summary of the auxiliary machine drive control processing concerning 1st Embodiment. The figure which shows the calculation result of the engine torque characteristic concerning the embodiment. The figure which shows the outline | summary of the calculation method of the average torque concerning the embodiment. The flowchart which shows the procedure of the torque limitation process concerning the embodiment. The flowchart which shows the procedure of the torque limitation process concerning 2nd Embodiment.

(First embodiment)
Hereinafter, a first embodiment in which a clutch protection device according to the present invention is applied to a series hybrid vehicle (range extender vehicle) including only a rotating machine as an in-vehicle main machine will be described with reference to the drawings.

  FIG. 1 shows a system configuration diagram according to the present embodiment.

  As shown in the figure, the vehicle includes a high-voltage battery 10, a multi-phase rotating machine (hereinafter referred to as a traveling motor generator 12) as an in-vehicle main machine, a multi-phase rotating machine for driving and generating power (hereinafter referred to as an auxiliary machine). A motor generator 14), an engine 16, an air conditioner (air conditioner), and the like are provided. Incidentally, the motor generator is specifically a three-phase permanent magnet synchronous motor (for example, an embedded magnet synchronous motor).

  The high-voltage battery 10 stores stored energy for driving the traveling motor generator 12 and the auxiliary motor generator 14. Further, the high voltage battery 10 is charged by power generation of the auxiliary motor generator 14 or by external charging equipment (for example, a quick charger or a household power source) via a plug (not shown) provided in the high voltage battery 10 or the like. The high voltage battery 10 supplies power to a low voltage battery (not shown) via a DC-DC converter (not shown). Moreover, as the high voltage battery 10, for example, a nickel metal hydride storage battery or a lithium ion storage battery can be employed.

  The traveling motor generator 12 is driven by supplying the stored energy of the high-voltage battery 10 via an inverter (traveling inverter 18) for controlling this. The drive energy generated by the travel motor generator 12 is transmitted to the drive wheels 22 via the speed change mechanism 20 or the like. The traveling motor generator 12 has a function of generating regenerative power when the vehicle is decelerated so as to charge the high voltage battery 10.

  The engine 16 is a four-stroke reciprocating engine with intake / compression / expansion / exhaust strokes as one combustion cycle (720 ° C. A), more specifically, a single-cylinder spark ignition engine. In the present embodiment, a single cylinder is adopted as the engine 16 for the purpose of simplifying the structure of the engine 16 and reducing the cost.

  The intake passage 24 of the engine 16 has an opening (throttle throttle) by an air flow meter 26 that detects the amount of intake air flowing through the intake passage 24 and an actuator such as a DC motor to adjust the flow area of the intake passage 24 in order from the upstream side. And a throttle valve 28 whose opening degree is adjusted.

  The engine 16 is provided with an electromagnetically driven fuel injection valve 16a that supplies fuel (gasoline) to the combustion chamber of the engine 16, and an ignition plug 16b that generates a discharge spark in the combustion chamber. The mixture of fuel and intake air supplied from the fuel injection valve 16a is used for combustion in the combustion chamber. The energy generated by the combustion of the air-fuel mixture is taken out as rotational energy of the output shaft (crankshaft 30) of the engine 16. Note that the air-fuel mixture subjected to combustion is discharged into the exhaust passage 32 as exhaust.

  The exhaust passage 32 is provided with an A / F sensor 34 and a catalyst 36 for purifying harmful components in the exhaust in order from the upstream side. Specifically, the A / F sensor 34 outputs a linear electric signal according to the oxygen concentration in the exhaust gas and unburned components (CO, HC, H2, etc.), and can detect a wide range of the air-fuel ratio of the air-fuel mixture. This is a full range air-fuel ratio sensor. The catalyst 36 is a three-way catalyst that purifies NOx, HC, and CO in the exhaust gas. The temperature of the catalyst 36 is within a predetermined activation temperature range (for example, 350 ° C. to 900 ° C.), and the air-fuel ratio of the air-fuel mixture is theoretically determined. The exhaust purification capacity can be maintained high in a state where the air-fuel ratio is close.

  The crankshaft 30 and the auxiliary motor generator 14 are mechanically coupled via a clutch 38. The clutch 38 is of an electromagnetic drive type that transmits or cuts power between the crankshaft 30 and the auxiliary motor / generator 14. More specifically, the clutch 38 includes a pair of disk-shaped members (such as a clutch disk). A friction clutch (for example, a multi-plate clutch).

  In the present embodiment, it is assumed that the clutch 38 can adjust the transmission torque between the crankshaft 30 and the auxiliary motor generator 14. In order to employ such a clutch, in this embodiment, a state where the transmission efficiency of the clutch 38 is greater than “0” and equal to or less than “1” is referred to as a transmission state of the clutch 38. The state set to “1” will be referred to as the engaged state of the clutch 38. That is, the engaged state refers to a state where the input torque and output torque of the clutch 38 are the same and the input side rotational speed and the output side rotational speed of the clutch 38 are the same. On the other hand, a state in which the transmission efficiency (transmission torque) of the clutch 38 is “0” is referred to as a disconnected state of the clutch 38.

  The auxiliary motor generator 14 has a function of generating power by being driven by the rotational energy of the crankshaft 30 to charge the high voltage battery 10. Specifically, the high-voltage battery 10 is charged by the generated energy of the auxiliary motor generator 14 by operating the inverter for the motor generator (auxiliary inverter 40) in a state where the clutch 38 is in the transmission state. The

  Further, the auxiliary motor generator 14 is mechanically connected to a compressor 42 provided in the air conditioner, and is driven by the supply of stored energy from the high voltage battery 10 via the auxiliary inverter 40, whereby the compressor 42 is driven. The auxiliary motor generator 14 also has a starter function for applying initial rotation (cranking) to the crankshaft 30 in a state where the clutch 38 is in a transmission state.

  Incidentally, the vehicle is provided with a cooling water circuit 44 for cooling various in-vehicle devices. Specifically, the cooling water circuit 44 includes a radiator 48 that cools the cooling water that flows through the cooling water circuit 44 by wind from a conde fan 46 that will be described later, or wind that is blown as the vehicle travels (running wind), an electric pump 50, and the like. It is configured with. The cooling water cooled by the radiator 48 by driving the electric pump 50 passes through the cooling water circuit 44 through the traveling motor generator 12, the traveling inverter 18, the auxiliary inverter 40, the auxiliary motor generator 14, and the engine 16. By flowing in sequence, the plurality of devices are cooled, or these temperatures are kept at appropriate temperatures.

  The air conditioner apparatus includes an air passage 52 that supplies warm air or cold air into the passenger compartment, and a refrigeration device for cooling the air flowing through the passage.

  The refrigeration apparatus includes the compressor 42 that sucks and discharges refrigerant to circulate the refrigerant in the refrigeration cycle, a condenser 54, an evaporator 56 (evaporator), and the like.

  Specifically, the compressor 42 is a variable capacity type capable of variably setting the refrigerant discharge amount by an energization operation of an electromagnetically driven actuator provided in the compressor 42. Note that the power required to drive the compressor 42 increases as the refrigerant discharge amount of the compressor 42 increases.

  The condenser 54 is a member that exchanges heat between air or traveling air blown from a fan (conde fan 46) or the like that is rotationally driven by a DC motor or the like, and refrigerant discharged from the compressor 42. The refrigerant flowing out of the condenser 54 is rapidly expanded / misted by an expansion valve (not shown), and the atomized refrigerant is supplied to an evaporator 56 provided in the air passage 52. In the evaporator 56, the air flowing through the air passage 52 is cooled by heat exchange between the air flowing through the air passage 52 and the mist refrigerant. The refrigeration cycle is provided with a refrigerant pressure sensor 57 that detects the refrigerant pressure on the discharge side of the compressor 42. Further, the refrigerant vaporized by the evaporator 56 is sucked into the suction port of the compressor 42.

  On the other hand, in addition to the evaporator 56, the air passage 52 is provided with a blower 58 that generates an air flow in the air passage 52, a heater (not shown) that heats the air flowing through the air passage 52, and the like. An evaporator temperature sensor 59 that detects the temperature (actual evaporator temperature) of the air heat-exchanged by the evaporator 56 is provided near the air-side outlet of the evaporator 56. Further, the blower 58 and the condenser fan 46 are connected to the low-voltage battery and are driven by using the battery as a power supply source.

  In such a configuration, the air blown by the blower 58 passes through the evaporator 56 and the like and is subjected to heat exchange so as to reach a desired temperature. The heat-exchanged air is supplied to the vehicle interior from an air outlet (not shown) formed in the air passage 52, thereby cooling or heating the vehicle interior.

  In the present embodiment, the clutch 38, the auxiliary motor generator 14 and the compressor 42 are unitized to form the power generation air conditioning unit 60. Hereinafter, this unit will be described with reference to FIG.

  FIG. 2 is a cross-sectional view of the power generation air conditioning unit 60. In the figure, only the auxiliary motor generator 14 and the clutch 38 are shown in cross-section.

  As illustrated, the clutch 38 and the auxiliary motor generator 14 are accommodated in a housing. The clutch 38 includes a rotor 38a, a stator 38b, and an armature 38c. Specifically, the rotor 38 a is mechanically connected to the crankshaft 30. An armature 38c is disposed at a position facing the rotor 38a.

  The auxiliary motor generator 14 includes a rotor 14a and a stator 14b. The compressor 42 is attached to the housing via a bracket 62.

  The armature 38c is connected to the rotor 14a via the leaf spring 64. The rotor 14a is connected to the drive shaft of the compressor 42 through a rubber damper baked on the inner periphery thereof.

  In such a configuration, the armature 38c is attracted to the stator 38b side by energizing the stator 38b, and the rotor 38a and the armature 38c are connected. As a result, the rotational energy of the crankshaft 30 is transmitted to the auxiliary motor generator 14 and the compressor 42. Then, the load torque of the auxiliary motor generator 14 and the compressor 42 is adjusted by energizing the stator 14b and the compressor 42. Since the crankshaft 30 and the rotors 14a and 38a are arranged coaxially, the rotation speeds of the crankshaft 30 and the rotors 14a and 38a are the same. The crankshaft 30 is connected to a disk-like flywheel 66 that suppresses rotational fluctuations in the low rotation range of the engine 16.

  Returning to the description of FIG. 1, the vehicle is provided with a rotation angle sensor 68 that detects the rotation angle position of the crankshaft 30 (the electrical angle of the auxiliary motor generator 14). Here, as the rotation angle sensor 68, for example, a resolver or an encoder can be employed.

  An electronic control unit (hereinafter referred to as ECU 70) is a microcomputer composed of a well-known CPU, ROM, RAM, and the like, each of which is a target of operation, such as the motor generator 12 for traveling, the motor generator 14 for auxiliary equipment, the engine 16 and the air conditioner. It is configured as. The ECU 70 includes output signals from a current sensor 72 that detects currents iv and iw flowing through the V-phase and W-phase of the auxiliary motor generator 14, the air flow meter 26, the A / F sensor 34, and the rotation angle sensor 68. Is entered. Based on these input signals, the ECU 70 performs an air conditioning control process for the vehicle interior by the air conditioner, a combustion control process for the engine 16, a drive control process for the traveling motor generator 12, and the like.

  The air conditioning control process is a process for energizing the compressor 42 to control the actual temperature detected by the temperature sensor 59 to the target value (target temperature). Here, the higher the actual evaporator temperature with respect to the target evaporator temperature, the greater the load torque of the compressor 42 in order to increase the refrigerant circulation amount of the refrigeration cycle.

  The combustion control process of the engine 16 is a process of energizing the fuel injection valve 16a to feedback control the air-fuel ratio of the air-fuel mixture detected by the A / F sensor 34 to a target air-fuel ratio (for example, near the theoretical air-fuel ratio). . Specifically, first, based on the intake air amount detected by the air flow meter 26, a base value of the fuel injection amount from the fuel injection valve 16a required to set the air-fuel ratio of the air-fuel mixture to the target air-fuel ratio is set. Then, the base value is corrected based on the deviation between the actual air-fuel ratio of the air-fuel mixture and the target air-fuel ratio. As a result, the corrected base value is set to be larger as the intake air amount is larger. Based on the corrected base value, the fuel injection valve 16a is energized. As a result, fuel corresponding to the corrected base value is injected from the fuel injection valve 16a.

  In the present embodiment, the ECU 70 performs a process of calculating the load torque of the compressor 42 based on the detection value of the refrigerant pressure sensor 57 and the like. Furthermore, each of the motor generator, the air conditioner device, the engine 16 and the like is actually operated by each of different electronic control devices, but these electronic control devices are represented as ECU 70 here.

  In particular, the ECU 70 performs auxiliary machine drive control processing. In this process, when it is determined that there is a power generation request for the auxiliary machine motor generator 14, a process for causing the auxiliary motor generator 14 to generate power using the engine 16 as a power supply source, or a drive request for the compressor 42 together with the power generation request. If it is determined that there is, this is a process of causing the auxiliary motor generator 14 to generate power and driving the compressor 42 using the engine 16 as a power supply source. More specifically, the engine rotational speed is feedback controlled to the target engine rotational speed (rotational speed FB control) by adjusting the load torque of the auxiliary motor generator 14 in a situation where the engine 16 is driven. Here, whether or not there is a power generation request may be determined based on, for example, whether or not the SOC of the high-voltage battery 10 is equal to or less than a specified value. Whether there is a request for driving the compressor 42 may be determined based on, for example, whether the required cooling load in the passenger compartment is greater than zero. If it is determined that there is no request for driving the compressor 42, the discharge capacity of the compressor 42 is set to “0”.

  Next, the accessory drive control processing according to the present embodiment will be described in detail with reference to FIG. FIG. 3 is a functional block diagram of auxiliary machine drive control processing according to the present embodiment.

  As shown in the figure, the setting unit B1 generates power corresponding to the auxiliary machine required power that is the total value of the required generated power of the auxiliary motor generator 14 and the required cooling load for air conditioning the vehicle interior. The target throttle opening Stgt and the target engine rotation speed Ntgt are set so as to be generated.

  In this embodiment, when it is determined that the auxiliary machine required power is at a predetermined low level (small required power mode), the target throttle opening Stgt is set to the first specified opening (Lo) and the target The engine speed Ntgt is set to a first specified speed Nt1 (for example, 2500 rpm). On the other hand, when it is determined that the auxiliary machine required power is a predetermined high level (large required power mode), the target throttle opening Stgt is set to a second specified opening (Hi) that is larger than the first specified opening. Then, the target engine speed Ntgt is set to a second specified speed Nt2 (eg, 3000 rpm) higher than the first specified speed Nt1. Incidentally, whether the mode is the low required power mode or the high required power mode may be determined based on, for example, whether or not the auxiliary required power is equal to or less than a predetermined value. In the present embodiment, from the viewpoint of reducing the pumping loss of the engine 16, the second specified opening is set to the maximum value (WOT) of the throttle opening.

  Here, in this embodiment, as shown in FIG. 4, the maximum value of the generated torque during one combustion cycle of the engine 16 for each engine rotation speed is set to the maximum torque Trmax for each speed, and the target engine rotation speed Ntgt is set to all the engines. Higher rotation speed than the engine rotation speed Nα corresponding to the maximum generated torque (indicated by “x” in the figure; see FIG. 5) that is the maximum value of the maximum torque Trmax for each speed during the rotation speed (for example, an area of 2000 rpm or more) Set to. This setting reduces the maximum torque (clutch capacity) that can be transmitted by the clutch 38 by setting the use rotation speed region of the engine 16 while avoiding the region near the engine rotation speed Nα where the torque fluctuation of the engine 16 is large. This is to reduce the size and cost of the clutch 38.

  Incidentally, when the target throttle opening degree Stgt is set in the setting unit B1, processing for controlling the opening degree of the throttle valve 28 to the target throttle opening degree Stgt is performed. If it is determined that the auxiliary machine required power is “0”, for example, the engine 16 is not instructed to start, and the target engine speed Ntgt is set to “0”.

  Returning to the description of FIG. 3, the speed calculation unit B <b> 2 calculates the engine rotation speed Nr based on the detection value θ of the rotation angle sensor 68.

  The rotational speed control unit B3 is a command voltage of a three-phase fixed coordinate system based on, for example, proportional integral control of the deviation ΔNr so that the deviation ΔNr of the engine rotational speed Nr and the target engine rotational speed Ntgt is zero. Command voltage Vu, V-phase command voltage Vv, and W-phase command voltage Vw. The command voltages Vu, Vv, Vw can be specifically set by, for example, current feedback control on condition that the deviation ΔNr is zero. In the present embodiment, the specified voltage is calculated by setting the command value of the actual current on the d axis, which is the actual current of the rotating two-phase coordinate system, to 0.

  The PWM modulation unit B4 is a PWM signal for operating the three-phase output voltage of the auxiliary machine inverter 40 as a voltage simulating the command voltages Vu, Vv, Vw (an operation signal for operating a switching element included in the auxiliary machine inverter 40). ) Is generated. Here, for example, a result of comparing the command voltages Vu, Vv, and Vw with the input voltage VINV of the auxiliary inverter 40 and a triangular wave carrier may be used as the PWM signal. Then, the generated PWM signal is output to the auxiliary machine inverter 40.

  By the way, the total load torque (loads of the auxiliary motor generator 14 and the compressor 42) input to the clutch 38 in a situation where the auxiliary motor generator 14 is driven by the auxiliary drive control process using the engine 16 as a power supply source. The engine speed may decrease due to a change in the total torque. As this factor, for example, there is a sudden decrease in the amount of traveling air blown to the condenser 54. Specifically, when the traveling wind rapidly decreases, the refrigerant pressure on the discharge side of the compressor 42 increases due to a decrease in the degree of heat dissipation in the condenser 54, and the load torque of the compressor 42 increases. When the load torque of the compressor 42 increases, the engine speed decreases. Here, the total load torque can be increased by increasing the load torque of the compressor 42 described above until the load torque of the auxiliary motor generator 14 is reduced to some extent by the rotational speed FB control.

  Another example of the factor is a sudden decrease in the load torque of the compressor 42. Specifically, the required cooling load may be reduced due to switching from the outside air mode that introduces outside air into the vehicle interior to the inside air mode that introduces inside air, or when the target set temperature in the vehicle interior is increased. is there. When the required cooling load is reduced, the load torque of the compressor 42 is rapidly reduced due to the rapid increase in the target evaporator temperature, and the engine speed is increased. Here, the total load torque can be increased due to the increase in the load torque of the auxiliary motor generator 14 in order to decrease the rotation speed of the crankshaft 30 with the flywheel 66 by the rotation speed FB control. Note that the total load torque can also be increased by increasing the power generated by the auxiliary motor generator 14 for some reason.

  When the total load torque input to the clutch 38 increases due to the above-described factors, the engine 16 is driven at an operating point corresponding to the total load torque. That is, the engine rotation speed decreases and the generated torque of the engine 16 increases. In particular, when the increase degree of the total load torque is large and the decrease degree of the engine rotation speed is large, the engine rotation speed decreases to the vicinity of the engine rotation speed Nα corresponding to the maximum generated torque, so that the torque fluctuation of the engine 16 is large. Therefore, the maximum torque Trmax for each speed may increase. Even under such circumstances, in order to ensure the reliability of the clutch 38, for example, as indicated by a two-dot chain line in FIG. 4, the clutch 38 having a clutch capacity larger than the maximum generated torque is employed. There is a concern that the clutch 38 cannot be downsized.

  In order to solve such a problem, in the present embodiment, when the total load torque exceeds the upper limit torque, a torque limiting process for limiting the total load torque to the upper limit torque or less is performed, whereby the total load torque input to the clutch is reduced. Reduce.

  In the present embodiment, the upper limit torque is set as a value that is equal to or greater than the maximum average torque of the engine 16 and less than the maximum generated torque of the engine 16, as indicated by a broken line in FIG. Here, as shown in FIG. 5, the maximum average torque is the maximum value among all engine rotation speeds among the average value Travel of the generated torque during one combustion cycle (720 ° C.) of the engine 16 at each engine rotation speed. That's it.

  In the figure, the minimum value of the generated torque during one combustion cycle of the engine 16 at each engine speed is indicated as Trmin. Here, the engine speed region where the difference between Trmax and Trmin is large indicates that the engine 16 has a large torque fluctuation (see FIG. 4 above).

  FIG. 6 shows the procedure of the torque limiting process according to this embodiment. This process is repeatedly executed by the ECU 70 at a predetermined cycle, for example.

  In this series of processing, first, in step S10, it is determined whether or not there is an instruction to start the engine 16. Here, whether or not there is an instruction to start the engine 16 may be determined based on whether or not there is a power generation request to the auxiliary motor generator 14.

  If an affirmative determination is made in step S10, the process proceeds to step S12 to determine whether or not the start completion flag F is “0”. Here, the start completion flag F indicates that the start of the engine 16 is not completed by “0”, and indicates that the start of the engine 16 is completed by “1”.

  If it is determined in step S12 that the start completion flag F is “0”, it is determined that the start of the engine 16 has not yet been completed. In steps S14 to S20, the engine 16 is started.

  Specifically, first, in step S14, a process of energizing the stator 38b is performed so that the clutch 38 is in an engaged state in a state where the rotation of both the crankshaft 30 and the auxiliary motor generator 14 is stopped. This process is a process for avoiding an increase in input torque to the clutch 38.

  That is, when the rotation of the crankshaft 30 is stopped and the clutch motor 38 is engaged while the accessory motor generator 14 is driven, the rotation speed of the crankshaft 30 is increased by the accessory motor generator 14. Due to the rapid increase, the input torque to the clutch 38 increases. In particular, in the present embodiment, since the flywheel 66 is connected to the crankshaft 30, there is a possibility that the degree of increase in input torque to the clutch 38 due to the clutch 38 being brought into the engaged state may become significant. In order to deal with such a problem, for example, the clutch 38 having a large clutch capacity is employed, and there is a concern that the clutch 38 cannot be downsized. For this reason, by providing the processing of this step, an increase in the input torque to the clutch 38 when the clutch 38 is engaged is avoided.

  In the subsequent step S16, cranking is started by the auxiliary motor generator 14, and the process waits until the engine speed Nr exceeds a threshold speed Nβ (for example, 2000 rpm). This process is a process for avoiding an increase in torque fluctuation of the engine 16 due to the start of the combustion control of the engine 16 when the engine 16 is started. Here, the threshold speed Nβ is set to a rotational speed higher than the engine rotational speed Nα corresponding to the maximum generated torque of the engine 16, for example.

  In the subsequent step S18, combustion control of the engine 16 including fuel injection control processing by the fuel injection valve 16a and ignition control processing by the spark plug 16b is started. Thereby, it is possible to drive the engine 16 while avoiding a region where the torque fluctuation of the engine 16 is large. Note that, when it is determined that the combustion control enables the self-driving of the engine 16 (complete explosion), the accessory drive control process is started.

  In the subsequent step S20, the start completion flag F is set to “1”.

  On the other hand, if it is determined in step S12 that the start completion flag F is “1”, it is determined that the engine 16 has already been started. In steps S22 and S24, torque limiting processing is performed.

  Specifically, first, in step S22, whether the total load torque, which is the total value of the load torque (MG torque Tmg) of the auxiliary motor generator 14 and the load torque of the compressor 42 (comp torque Tcmp), exceeds the upper limit torque. Judge whether or not. In the present embodiment, the MG torque Tmg is calculated based on the actual current Iq on the q axis, which is the actual current in the rotating two-phase coordinate system of the auxiliary motor generator 14. Here, the actual current Iq on the q axis may be calculated based on, for example, the detected value θ of the rotation angle sensor 68 and the detected values iv and iw of the V-phase and W-phase currents by the current sensor 72.

  Incidentally, when it is determined that there is no request for driving the compressor 42, it is determined whether or not the MG torque Tmg exceeds the upper limit torque. In this case, the current value on the q-axis required for the auxiliary motor generator 14 to generate the upper limit torque is set as the specified current value, and it is determined that the actual current Iq on the q-axis exceeds the specified current value. In this case, it may be determined that the MG torque Tmg exceeds the upper limit torque.

  When an affirmative determination is made in step S22, the process proceeds to step S24, and a process of limiting the total load torque with the upper limit torque is performed. Specifically, the increase in the MG torque Tmg is prohibited or the MG torque Tmg is decreased by energization operation of the auxiliary inverter 40, so that the total load torque is made lower than the upper limit torque. As a result, the total load torque is limited by the upper limit torque, and a decrease in the engine rotation speed is suppressed, and an increase in the maximum torque Trmax for each speed of the engine 16 can be suppressed. That is, it is possible to suppress the amount of decrease in the engine rotational speed toward the engine rotational speed Nα corresponding to the maximum generated torque, and it is possible to suppress the increase in the input torque to the clutch 38. Incidentally, when it is determined that there is no request for driving the compressor 42, a process may be performed in which the actual current Iq on the q-axis is made equal to or less than the specified current value.

  When a negative determination is made in steps S10 and S22, or when the processes in steps S20 and S24 are completed, this series of processes is temporarily ended.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) When it is determined that the total load torque exceeds the upper limit torque, a torque limiting process, such as a process of reducing the MG torque Tmg, to reduce the total load torque to the upper limit torque or less is performed. As a result, an increase in input torque to the clutch 38 can be suppressed, and the clutch capacity can be reduced, for example, by setting the clutch capacity to a value that is less than the maximum generated torque and greater than the MG upper limit torque. That is, the size of the clutch 38 can be reduced.

  (2) An auxiliary machine drive control process for adjusting the MG torque Tmg is performed so as to feedback-control the engine rotational speed Nr to the target engine rotational speed Ntgt while causing the engine 16 to generate power commensurate with the auxiliary machine required power. Here, the target engine speed Ntgt is set higher than the engine speed corresponding to the maximum generated torque. For this reason, even if the total load torque increases due to some factor, an increase in the input torque to the clutch 38 can be suitably suppressed by the torque limiting process.

  (3) When it is determined that the engine 16 has been instructed to start, prior to cranking, the clutch 38 is engaged with both the auxiliary motor generator 14 and the crankshaft 30 stopped rotating. Processed. Thereby, when the engine 16 is started, it is possible to avoid an increase in input torque to the clutch 38 due to the clutch 38 being engaged.

  (4) After cranking is started, the engine speed is increased by cranking to a rotational speed higher than the engine speed Nα corresponding to the maximum generated torque, and then combustion control of the engine 16 is started. Thereby, it is possible to drive the engine 16 while avoiding a region where the torque fluctuation of the engine 16 is large, and it is possible to suitably suppress an increase in vibration accompanying the driving of the engine 16.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, as the torque limiting process, when it is determined that the total load torque exceeds the upper limit torque, a process of reducing the transmission torque of the clutch 38 by the energization operation of the clutch 38 is performed.

  FIG. 7 shows the procedure of the torque limiting process according to this embodiment. This process is repeatedly executed by the ECU 70 at a predetermined cycle, for example. In FIG. 7, the same steps as those shown in FIG. 6 are given the same step numbers for the sake of convenience.

  In this series of processes, if an affirmative determination is made in step S22, the process proceeds to step S26. In step S26, a process of energizing the clutch 38 is performed in order to reduce the transmission torque of the clutch 38 (in order to place the clutch 38 in a half-clutch state). According to this process, since the torque input from the auxiliary motor generator 14 side to the engine 16 side is reduced, the engine rotation speed Nr becomes higher than the target engine rotation speed Ntgt. The maximum torque Trmax is reduced. Thereby, the increase in the input torque to the clutch 38 is suppressed.

  Incidentally, in order to avoid that the MG torque Tmg is excessively increased by the rotational speed FB control, a process for temporarily stopping the rotational speed FB control during a period in which the total load torque is assumed to exceed the upper limit torque is performed. Also good. After that, when the clutch 38 is in the engaged state, it is desirable to perform a process of gradually increasing the transmission efficiency of the clutch 38 toward “1”, for example, in order to avoid a sudden increase in input torque to the clutch 38.

  When a negative determination is made in steps S10 and S22, or when the processes in steps S20 and S26 are completed, the series of processes is temporarily ended.

  Thus, in the present embodiment, an increase in input torque to the clutch 38 can be suitably suppressed by performing a process of reducing the transmission torque of the clutch 38 as the torque limiting process.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  The auxiliary drive control processing method is not limited to the one exemplified in the first embodiment. For example, the power generation of the auxiliary motor generator 14 will be described. The auxiliary inverter 40 may be energized to feedback control the actual generated power of the auxiliary motor generator 14 to the target generated power. In this case, the target generated power may be set to one or several steps, and the target throttle opening Stgt and the target engine rotation speed Ntgt may be set so that the engine 16 generates power corresponding to the target generated power.

  In the first embodiment, when it is determined that the frequency at which the total load torque is determined to exceed the upper limit torque is high, a process for increasing the target engine speed Ntgt may be performed. According to this process, the engine speed Nr can be separated from the engine speed Nα corresponding to the maximum generated torque to the high speed side, and the input torque to the clutch 38 frequently tends to exceed the upper limit torque. Suppression of the occurrence can be expected.

  In the first embodiment, the actual current on the d-axis of the auxiliary motor generator 14 is set to “0”, but the present invention is not limited to this. For example, the absolute value of the actual current on the d-axis may be set to a value larger than 0 in order to use the reluctance torque of the auxiliary motor generator 14. In this case, the MG torque Tmg may be grasped using a map or the like in which the MG torque Tmg is associated with the actual current on the d-axis and the actual current on the q-axis.

  In each of the above embodiments, when a speed change mechanism is provided between the crankshaft 30 and the auxiliary motor generator 14, the torque obtained by converting the total load torque by the speed change ratio of the speed change mechanism can be grasped as the input torque to the clutch 38. That's fine.

  In the first embodiment, the control logic for changing the target engine rotation speed Ntgt according to the low required power mode and the high required power mode is adopted, but the present invention is not limited to this. For example, a control logic may be adopted in which the target engine speed Ntgt is set to one (for example, 3000 rpm) and only the target throttle opening degree Stgt is changed according to the small required power mode and the large required power mode. In addition, for example, a control logic that sets the target engine speed Ntgt to one and changes the ignition timing by the spark plug 16b to the advance side or the retard side according to the low required power mode and the high required power mode is adopted. May be.

  In the first embodiment, the power to be generated by the engine 16 according to the auxiliary machine required power is set in two stages. However, the present invention is not limited to this. For example, the power to be generated by the engine 16 according to the auxiliary machine required power. May be set in multiple stages of three or more stages.

  -The rotating machine is not limited to a synchronous rotating machine but may be an induction rotating machine.

  In the above embodiment, the engine speed is feedback-controlled to the target engine speed by adjusting the MG torque Tmg, but this is not limitative. For example, the feedback control may be performed by adjusting the comp torque Tcmp in addition to the MG torque Tmg.

  The electronically controlled device that can adjust its own load torque mounted on the vehicle is not limited to both the auxiliary motor generator 14 and the compressor 42, and may be any one of them. Further, the device is not limited to the auxiliary motor generator 14 and the compressor 42, and may be, for example, the electric pump 50 of the cooling water circuit 44. In this case, the process of reducing the load torque of the device may be a process of stopping the driving of the electric pump 50, for example.

  The engine is not limited to a spark ignition type internal combustion engine such as a gasoline engine, but may be a compression ignition type internal combustion engine such as a diesel engine. Further, the engine is not limited to a single cylinder, and may be a plurality of cylinders. Furthermore, the system to which the present invention is applied is not limited to the in-vehicle system.

  DESCRIPTION OF SYMBOLS 14 ... Motor generator for auxiliary machines, 16 ... Engine, 30 ... Crankshaft, 38 ... Clutch, 42 ... Compressor, 70 ... ECU (one Embodiment of the protection apparatus of a clutch).

Claims (8)

An electronically controlled device capable of adjusting its own load torque, an engine mechanically connected to the device and serving as a power supply source for the device, and a state of transmitting or interrupting power between the engine and the device Applied to a system comprising a clutch to be in a state,
Based on the fact that the power input between the engine and the device is transmitted by the clutch and the device is driven using the engine as a power supply source, the torque input to the clutch exceeds the specified torque. A clutch protection device comprising torque limiting means for performing a process of limiting a load torque of the device by energizing operation of the device so as to limit a torque input to the clutch to be equal to or less than the specified torque. Combustion control means for performing combustion control of the engine to cause the engine to generate power required for driving the device;
A load torque adjusting means for adjusting a load torque of the device so as to control the engine rotation speed to the target value under a situation where the combustion control is performed by the combustion control means;
The maximum value of all the rotational speeds among the maximum values of the generated torque during one combustion cycle of the engine at each engine speed is defined as the maximum generated torque
The target value is set on the higher rotation side than the engine rotation speed corresponding to the maximum generated torque,
The clutch protection device according to claim 1, wherein the specified torque is set to a value smaller than the maximum generated torque. A system comprising an engine, a device that is mechanically coupled to the engine and driven by the engine as a power supply source, and a clutch that is energized to adjust a transmission torque between the engine and the device. Applied,
Combustion control means for performing combustion control of the engine to cause the engine to generate power required for driving the device;
In a situation where the power between the engine and the device is in a transmission state by the clutch and the combustion control is performed by the combustion control means, the engine speed is controlled to the target value. Load torque adjusting means for adjusting the load torque;
In a situation where the load torque of the device is adjusted by the load torque adjusting means, the clutch input torque is set to be less than the specified torque based on the fact that the torque input to the clutch exceeds the specified torque. Torque limiting means for performing a process of reducing the transmission torque by an energization operation of
The maximum value of all the rotational speeds among the maximum values of the generated torque during one combustion cycle of the engine at each engine rotational speed is defined as the maximum generated torque.
The target value is set on the higher rotation side than the engine rotation speed corresponding to the maximum generated torque,
The protection device for a clutch, wherein the specified torque is set to a value smaller than the maximum generated torque. The equipment includes a rotating machine having a function of imparting initial rotation to the output shaft of the engine,
If it is determined that the engine has been instructed to start, prior to applying an initial rotation to the output shaft by the rotating machine, the clutch causes the clutch to rotate with both the rotating machine and the output shaft stopped. The clutch protection device according to any one of claims 1 to 3, further comprising start-up processing means for transmitting power between the output shaft and the rotating machine. The maximum value of all the rotational speeds among the maximum values of the generated torque during one combustion cycle of the engine at each engine rotational speed is defined as the maximum generated torque.
The start time processing means increases the engine rotation speed by applying the initial rotation to a rotation speed higher than the engine rotation speed corresponding to the maximum generated torque, and then starts combustion control of the engine. The clutch protection device according to claim 4. The equipment includes a rotating machine,
6. The torque limiting device according to claim 1, wherein the torque limiting unit determines whether or not a torque input to the clutch exceeds the specified torque based on a current flowing through the rotating machine. The clutch protection device as described.   The clutch protection device according to claim 1, wherein the device includes a rotating machine and a compressor for air conditioning.   The clutch protection device according to any one of claims 1 to 7, wherein the engine is a single cylinder engine.

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