Vehicle control devices

Abstract

To appropriately calculate a torque capacity factor of a torque converter.SOLUTION: A vehicle control device used for a hybrid vehicle comprises an engine connected to wheel through a power transmission passage and a motor generator installed in the power transmission passage. The vehicle control device has: a torque converter positioned between the engine and the motor generator; a clutch mechanism positioned between the motor generator and the wheels; and a control system provided with a processor and a memory. The control system: performs control to put the engine in an operation state with the clutch mechanism released and calculates power generation torque of the motor generator with the same controlled to be in a power generation state; and calculates a torque capacity factor of the torque converter on the basis of output torque thereof calculated from the power generation torque.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to a vehicle control device used in a hybrid vehicle.

Background Art

[0002] As a power train mounted on a hybrid vehicle, a power train including an engine and a torque converter has been developed (see Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, since there are individual differences in torque converters produced in large quantities, there is a risk that the torque capacity coefficient for each torque converter will vary. When the torque capacity coefficient of the torque converter is small, there is a risk that the output torque of the torque converter will be small, and when the torque capacity coefficient of the torque converter is large, there is a risk that the output torque of the torque converter will be large. That is, in order to appropriately control the power train of a hybrid vehicle, it is required to appropriately calculate the torque capacity coefficient of the torque converter.

[0005] An object of the present invention is to appropriately calculate the torque capacity coefficient of a torque converter.

Means for Solving the Problems

[0006] A vehicle control device according to one embodiment is a vehicle control device used in a hybrid vehicle, comprising: an engine connected to the wheels via a power transmission path; a motor generator provided in the power transmission path; a torque converter provided in the power transmission path and located between the engine and the motor generator; a clutch mechanism provided in the power transmission path and located between the motor generator and the wheels; and a control system comprising a processor and memory communicated with each other, which controls the engine, the motor generator, the torque converter and the clutch mechanism, wherein the control system releases the clutch mechanism, controls the engine to an operating state, and controls the motor generator to a power generation state, and calculates the power generation torque of the motor generator, and the control system calculates the torque capacity coefficient of the torque converter based on the output torque of the torque converter calculated from the power generation torque. [Effects of the Invention]

[0007] According to one aspect of the present invention, the control system calculates the generated torque of the motor generator while disengaging the clutch mechanism, controlling the engine to an operating state, and controlling the motor generator to a power generation state. The control system also calculates the torque capacity coefficient of the torque converter based on the output torque of the torque converter calculated from the generated torque. This makes it possible to appropriately calculate the torque capacity coefficient of the torque converter. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows an example of a hybrid vehicle in which a vehicle control device, according to one embodiment of the present invention, is used. [Figure 2] This figure shows an example of a vehicle control device. [Figure 3] This is a diagram showing an example of the basic structure of a control unit. [Figure 4] This figure shows an example of a torque converter performance curve. [Figure 5]This figure shows an example of a torque converter performance curve. [Figure 6] This flowchart shows an example of the execution procedure for calculating the capacity coefficient. [Figure 7] This flowchart shows an example of the execution procedure for calculating the capacity coefficient. [Figure 8] This flowchart shows an example of the execution procedure for calculating the capacity coefficient. [Figure 9] This timing chart shows an example of the execution status of the capacity coefficient calculation control. [Figure 10] This figure shows an example of the execution status of the capacity coefficient calculation control. [Figure 11] This flowchart shows an example of the procedure for executing target torque correction control. [Figure 12] This figure shows an example of a torque correction coefficient. [Figure 13] This figure shows an example of the changes in engine torque and turbine torque. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below with reference to the drawings. In the following description, identical or substantially identical components and elements will be denoted by the same reference numerals, and repeated descriptions will be omitted.

[0010] [Hybrid vehicles] Figure 1 shows an example of a hybrid vehicle 11 using a vehicle control device 10, which is one embodiment of the present invention. As shown in Figure 1, the hybrid vehicle 11 is equipped with a powertrain 14 consisting of an engine 12 and a transmission 13. The transmission 13 incorporates a torque converter 15, a motor generator 16, and a gear shift mechanism 17, etc. The gear shift output shaft 18 of the transmission 13 is connected to the wheels 22 via a propeller shaft 19, a differential mechanism 20, and a drive shaft 21. The powertrain 14 shown is a rear-wheel drive powertrain, but is not limited to this, and may also be a front-wheel drive or all-wheel drive powertrain.

[0011] Figure 2 shows an example of a vehicle control device 10. As shown in Figure 2, the transmission 13 of the powertrain 14 is equipped with a transmission mechanism 17 such as an automatic transmission or a continuously variable transmission. The transmission input shaft 23 of the transmission mechanism 17 is connected to the engine 12 via a forward clutch (clutch mechanism) 24, a motor generator 16, a separation clutch 25, and a torque converter 15. The transmission output shaft 18 of the transmission mechanism 17 is connected to the wheels 22 via a propeller shaft 19, a differential mechanism 20, and a drive shaft 21. The forward clutch 24 is a clutch mechanism that separates the engine 12 and motor generator 16, which are power sources, from the wheels 22, and is a clutch mechanism that constitutes part of a forward / reverse switching mechanism consisting of a planetary gear train or the like.

[0012] As shown in Fig. 2, the engine 12 and the wheels 22 are connected via a power transmission path 30 composed of a transmission mechanism 17 and the like. In the example shown in Fig. 2, the power transmission path 30 is composed of a crankshaft 31, a torque converter 15, a turbine shaft 32, a disconnect clutch 25, a motor generator 16, a forward clutch 24, a transmission mechanism 17, a propeller shaft 19, a differential mechanism 20, a drive shaft 21, and the like. Thus, the power transmission path 30 connecting the engine 12 and the wheels 22 is provided with a torque converter 15, a motor generator 16, and a forward clutch 24. Further, the torque converter 15 is located between the engine 12 and the motor generator 16, and the forward clutch 24 is located between the motor generator 16 and the wheels 22.

[0013] To control the torque converter 15, the disconnect clutch 25, the forward clutch 24, the transmission mechanism 17, and the like, the transmission 13 is provided with a valve body 33 composed of a plurality of solenoid valves, an oil passage, and the like. Further, an oil pump 34 driven by the engine 12 or an electric motor is connected to the valve body 33. The oil pumped from the oil pump 34 is controlled in terms of the supply destination, pressure, etc. via the valve body 33 and supplied to the torque converter 15, the forward clutch 24, and the like. Further, a transmission control unit 35 is connected to the valve body 33 to control the valve body 33.

[0014] The intake manifold 40 of the engine 12 is provided with a throttle valve 41 for adjusting the intake air amount. Further, the engine 12 is provided with an injector 42 for injecting fuel into the intake port and the cylinder, and an ignition device 43 composed of an ignition coil, an ignition plug, and the like. To control the engine torque and the engine speed, an engine control unit 44 is connected to the throttle valve 41, the injector 42, the ignition device 43, and the like. [[ID=X]]

[0015] [[ID=Y]] The motor generator 16 includes a stator 51 around which the stator coil 50 is wound, and a rotor 52 housed in the cylindrical stator 51. An inverter 54 is connected to the stator 51, and a battery pack 55 is connected to the inverter 54. A motor control unit 56 is also connected to the inverter 54 in order to control the motor generator 16 via the inverter 54. The motor control unit 56 controls the energization state of the stator coil 50 by controlling the inverter 54, which consists of multiple switching elements, and thereby controls the motor torque (actuation torque, generation torque) and motor speed of the motor generator 16.

[0016] [Control System] As shown in Figure 2, the vehicle control device 10 is equipped with a control system 60 consisting of multiple electronic control units for controlling the powertrain 14. The electronic control units constituting the control system 60 include the aforementioned transmission control unit 35, engine control unit 44, and motor control unit 56, as well as a vehicle control unit 61 that outputs control signals to these control units 35, 44, and 56. These control units 35, 44, 56, and 61 are connected to each other so as to be able to communicate via an in-vehicle network 62 such as CAN. The vehicle control unit 61 sets operating targets for the engine 12, motor generator 16, etc., based on input information from various control units and various sensors described later. It then generates control signals according to the operating targets for the engine 12, motor generator 16, etc., and outputs these control signals to the engine control unit 44, motor control unit 56, etc.

[0017] Sensors connected to the vehicle control unit 61 include an accelerator sensor 63 for detecting the amount of operation of the accelerator pedal and a brake sensor 64 for detecting the amount of operation of the brake pedal. Additionally, sensors connected to the vehicle control unit 61 include an engine speed sensor 65 for detecting the engine speed, which is the rotational speed of the crankshaft 31; a turbine speed sensor 66 for detecting the turbine speed, which is the rotational speed of the turbine shaft 32; and a vehicle speed sensor 67 for detecting the vehicle speed, which is the driving speed, from the rotational speed of the transmission output shaft 18. Furthermore, sensors connected to the vehicle control unit 61 include a motor speed sensor 68 for detecting the motor speed, which is the rotational speed of the rotor shaft 53 connected to the rotor 52; and a current sensor 69 for detecting the current supplied to the stator coil 50. The vehicle control unit 61 is also connected to a start switch 70, which is operated by the driver when the control system 60 is started, and a position switch 72 for detecting the driver's position of the select lever 71.

[0018] Figure 3 shows an example of the basic structure of control units 35, 44, 56, and 61. As shown in Figure 3, the electronic control units 35, 44, 56, and 61 have a microcontroller 82 that incorporates a processor 80 and main memory (memory) 81, etc. A predetermined program is stored in the main memory 81, and the program is executed by the processor 80. The processor 80 and the main memory 81 are connected to each other so as to be able to communicate with each other. Note that the microcontroller 82 may incorporate multiple processors 80, and the microcontroller 82 may also incorporate multiple main memory 81.

[0019] Furthermore, control units 35, 44, 56, and 61 are equipped with an input circuit 83, a drive circuit 84, a communication circuit 85, an external memory 86, and a power supply circuit 87, etc. The input circuit 83 converts signals input from various sensors into signals that can be input to the microcontroller 82. The drive circuit 84 generates drive signals for various devices such as the inverter 54 and valve body 33 based on signals output from the microcontroller 82. The communication circuit 85 converts signals output from the microcontroller 82 into communication signals for other control units. The communication circuit 85 also converts communication signals received from other control units into signals that can be input to the microcontroller 82. In addition, the power supply circuit 87 supplies a stable power supply voltage to the microcontroller 82, input circuit 83, drive circuit 84, communication circuit 85, and external memory 86, etc. Furthermore, the external memory 86, which consists of non-volatile memory, stores programs and various data.

[0020] [Torque converter] As shown in Figure 2, the torque converter 15 has a pump shell 90 connected to the crankshaft 31 of the engine 12. The torque converter 15 has a pump impeller 91 fixed to the pump shell 90 and a turbine runner 92 facing the pump impeller 91. The turbine shaft 32, which is the output shaft of the torque converter 15, is connected to the turbine runner 92. Furthermore, a clutch that directly connects the pump impeller 91 and the turbine runner 92, that is, a lock-up clutch 93 that directly connects the crankshaft 31 and the turbine shaft 32, is provided inside the pump shell 90.

[0021] By releasing the lock-up clutch 93, the crankshaft 31 and the turbine shaft 32 are disconnected, and torque is transmitted from the crankshaft 31 to the turbine shaft 32 via the torque converter 15, which is a sliding element. In other words, the torque input from the crankshaft 31 to the pump impeller 91 is transmitted from the pump impeller 91 to the turbine runner 92 via oil, and output from the turbine shaft 32 of the turbine runner 92. By engaging the lock-up clutch 93, the crankshaft 31 and the turbine shaft 32 can be directly connected, and torque can be directly transmitted from the crankshaft 31 to the turbine shaft 32.

[0022] Figures 4 and 5 show examples of performance curves for the torque converter 15. As shown in Figure 4, the horizontal axis represents the speed ratio e (e=N2 / N1), and the vertical axis represents the torque ratio t (t=T2 / T1), efficiency η (η=t×e), and torque capacity coefficient C (C=T1 / N1). 2 The following is shown. Thus, the characteristics of the torque converter 15 are expressed by the torque ratio t with respect to the speed ratio e, the efficiency η, and the torque capacity coefficient C. N1 is the input rotational speed of the torque converter 15, i.e., the engine rotational speed Ne, and N2 is the output rotational speed of the torque converter 15, i.e., the turbine rotational speed Nt. Also, T1 is the input torque of the torque converter 15, and T2 is the output torque of the torque converter 15.

[0023] Incidentally, in order to ensure the starting performance of the hybrid vehicle 11 equipped with a torque converter 15, it is important to accurately determine the torque capacity coefficient C of the torque converter 15. Since there are individual differences in the torque converters 15 that are mass-produced, there is a risk that the torque capacity coefficient C will vary from vehicle to vehicle. In other words, as shown by the dashed line Cb in Figure 5, if a torque converter 15 with a torque capacity coefficient C smaller than the reference coefficient Ca is installed, there is a risk that the output torque T2 of the torque converter 15 will be insufficient, reducing the vehicle's starting performance. On the other hand, as shown by the dashed line Cc in Figure 5, if a torque converter 15 with a torque capacity coefficient C larger than the reference coefficient Ca is installed, there is a risk that the output torque T2 of the torque converter 15 will be excessive, resulting in excessive torque being input to the forward clutch 24, etc. Therefore, the control system 60 performs the capacity coefficient calculation control described later in order to determine the torque capacity coefficient C of the torque converter 15 installed in its own vehicle.

[0024] [Capacity coefficient calculation control (flowchart)] Figures 6, 7, and 8 are flowcharts illustrating an example of the execution procedure for capacity coefficient calculation control. The flowcharts shown in Figures 6 to 8 are connected to each other at points labeled A and B. Each step of the capacity coefficient calculation control shown in Figures 6 to 8 represents a process executed by the processor 80 that constitutes the control system 60. Furthermore, the capacity coefficient calculation control shown in Figures 6 to 8 is a control that is executed by the control system 60 at predetermined intervals after the control system 60 is started up.

[0025] As shown in Figure 6, in step S10, it is determined whether or not the preconditions for the capacity coefficient calculation control are met. Here, the conditions under which the preconditions are met are, for example, when the forward range (D range) is selected by the driver's selector lever operation, the brake pedal is pressed by the driver, and the vehicle speed is maintained at 0 [km / h]. In step S10, if it is determined that the preconditions are not met, the routine is exited without performing the calculation process of the torque capacity coefficient C. On the other hand, if it is determined that the preconditions are met in step S10, the process proceeds to step S11.

[0026] In step S11, it is determined whether the execution flag FL1 is set to "1". Here, the situation in which the execution flag FL1 is set to "1" is, for example, a situation in a repair shop where a work terminal such as a personal computer is connected to the vehicle's control system 60, and the operation to start the capacity coefficient calculation control is performed on the work terminal. If it is determined in step S11 that the execution flag FL1 is set to "1", the process proceeds to each step from step S12 onward, and the process for calculating the torque capacity coefficient C is executed. On the other hand, if it is determined in step S11 that the execution flag FL1 is "0", the routine is exited without executing the torque capacity coefficient C calculation process.

[0027] In step S11, if it is determined that the execution flag FL1 is set to "1", the process proceeds to step S12, and the idling speed of the engine 12 is increased. Subsequently, in step S13, the forward clutch 24 is controlled to be in the disengaged state, and in the following step S14, the motor generator 16 is controlled to be in the power generation state. Once power generation by the motor generator 16 has started, the process proceeds to step S15, where the power generation current ig of the motor generator 16, the input rotational speed N1 of the motor generator 16, and the output rotational speed N2 of the motor generator 16 are read. As mentioned above, the input rotational speed N1 is the engine rotational speed Ne, and the output rotational speed N2 is the turbine rotational speed Nt.

[0028] As shown in Figure 7, in step S16, the generated torque Tm of the motor generator 16 is calculated based on the generated current ig of the stator coil 50. In step S16, the larger the generated current ig flowing through the stator coil 50, the larger the generated torque Tm calculated. Subsequently, in step S17, the output torque T2 of the torque converter 15 is calculated by multiplying the generated torque Tm by a predetermined coefficient k1, as shown in equation (1) below. Here, the predetermined coefficient k1 included in equation (1) is a coefficient for converting the generated torque Tm to the output torque T2, that is, a coefficient for converting the torque of the rotor shaft 53 to the torque of the turbine shaft 32. In the illustrated example, since a separation clutch 25 is provided between the turbine shaft 32 and the rotor shaft 53, the predetermined coefficient k1 is set based on the torque transmission efficiency of the engaged separation clutch 25. Also, for example, if a gear train is provided between the turbine shaft 32 and the rotor shaft 53, the predetermined coefficient k1 is set based on the gear ratio and torque transmission efficiency of the gear train. T2 = Tm × k1 ··(1)

[0029] In step S18, the speed ratio e of the torque converter 15 is calculated by dividing the output rotational speed N2 by the input rotational speed N1, as shown in equation (2) below. In step S19, the efficiency η of the torque converter 15 is calculated from the speed ratio e by referring to the performance curve diagram in Figure 4 using the speed ratio e. In the following step S20, the input torque T1 of the torque converter 15 is calculated based on the output torque T2, speed ratio e, and efficiency η, as shown in equation (3) below. In this way, the output torque T2 of the torque converter 15 is calculated from the generated torque Tm of the motor generator 16, and the input torque T1 of the torque converter 15 is calculated from this output torque T2. e = N² / N1 ··(2) T1 = T2 × e / η ··(3)

[0030] As shown in Figure 8, in step S21, the torque capacity coefficient C of the torque converter 15 is calculated based on the input torque T1 and input rotational speed N1, as shown in equation (4) below. In the following step S22, the difference Cs of the torque capacity coefficient C is calculated by subtracting the reference coefficient Ca from the torque capacity coefficient C, as shown in equation (5) below. Once the difference Cs is calculated, the process proceeds to step S23, where the forward clutch 24 is controlled to be engaged, then to step S24, where the motor generator 16 is controlled to stop generating electricity, and finally to step S25, where the idling speed of the engine 12 is reduced. C = T1 / N1 2 (4) Cs = C - Ca ··(5)

[0031] [Capacity coefficient calculation control (timing chart)] Next, the capacity coefficient calculation control described above will be explained using a timing chart. Figure 9 is a timing chart showing an example of the execution status of the capacity coefficient calculation control, and Figure 10 is a diagram showing an example of the execution status of the capacity coefficient calculation control.

[0032] As shown in Figure 9, at time t1, the D range flag is set to "1" due to the selection of the forward range (symbol a1), the brake flag is set to "1" due to the depression of the brake pedal (symbol b1), and the stop flag is set to "1" because the vehicle speed is 0 [km / h] (symbol c1). When the D range flag, brake flag, and stop flag are all set to "1" in this way, it is determined that the preconditions for the capacity coefficient calculation control described above are met. The control system 60 sets the D range flag based on the output signal of the position switch 72, the brake flag based on the output signal of the brake sensor 64, and the stop flag based on the output signal of the vehicle speed sensor 67.

[0033] Here, as shown in Figure 10, at time t1, the engine 12 is controlled to be in an idling state, i.e., in operation, and the forward clutch 24 is controlled to be in a engaged state by selecting the forward range. Furthermore, since the forward clutch 24 is engaged while the vehicle is stationary, the turbine shaft 32 and rotor shaft 53 are stopped, and the torque converter 15 driven by the engine 12 is in a slip state. Note that in the capacity coefficient calculation control, the lock-up clutch 93 of the torque converter 15 is held in a disengaged state.

[0034] As shown in Figure 9 at time t2, when the execution flag FL1 is set to "1" by the operator's terminal operation (symbol d1), the engine speed Ne is increased in preparation for the increase in engine load associated with subsequent power generation (symbol e1). Subsequently, as shown at time t3, when the engine speed Ne reaches a predetermined speed (symbol e2), the clutch hydraulic pressure Pc supplied to the forward clutch 24 is reduced (symbol f1), and the forward clutch 24 is controlled from the engaged state to the released state.

[0035] As shown above, when the forward clutch 24 is controlled to be released, the constraint on the rotor 52 by the forward clutch 24 is released, and as shown at time t4, the turbine speed Nt and motor speed Nm increase toward the engine speed Ne (symbol g1). In addition, as the forward clutch 24 is released, the motor generator 16 is controlled to be generating power, so the generated torque Tm of the motor generator 16 increases with the increase in motor speed Nm (symbol h1). Then, as shown at time t5, when the rate of change of the generated torque Tm stabilizes, the control system 60 acquires the generated torque Tm, engine speed Ne, and turbine speed Nt (symbols h2, e3, g2). In other words, the control system 60 calculates the generated torque Tm from the generated current ig and reads the input speed N1 and output speed N2.

[0036] Thus, once the control system 60 obtains the generated torque Tm, input rotational speed N1, and output rotational speed N2, the control system 60 calculates the output torque T2 from the generated torque Tm, as explained in the flowchart above. Here, as shown in Figure 10, at time t5, the transmission mechanism 17 and the like are disconnected from the motor generator 16 by the release of the forward clutch 24, and the motor generator 16 is rotated by the engine 12. Under these conditions, almost all of the output torque T2 of the torque converter 15 is consumed by the motor generator 16 in the power generation state, so the output torque T2 can be calculated accurately using the generated torque Tm. Once the output torque T2 is calculated accurately, the input torque T1 is calculated from the output torque T2 and efficiency η, and the torque capacity coefficient C is calculated from the input rotational speed N1 and input torque T1.

[0037] As explained above, the control system 60 calculates the generated torque Tm of the motor generator 16 while disengaging the forward clutch 24, controlling the engine 12 to the operating state, and controlling the motor generator 16 to the power generation state. Subsequently, the control system 60 calculates the torque capacity coefficient C of the torque converter 15 based on the output torque T2 of the torque converter 15 calculated from the generated torque Tm. In this way, the output torque T2 can be calculated accurately using the generated torque Tm, and the torque capacity coefficient C can be calculated accurately using this output torque T2. In other words, when calculating the torque capacity coefficient C of the torque converter 15, the output torque T2 calculated from the generated torque Tm is used instead of the engine torque, so the torque capacity coefficient C can be calculated accurately.

[0038] As shown in Figure 9 at time t6, once the torque capacity coefficient C of the torque converter 15 is calculated, the control system 60 sets the execution flag FL1 to "0" (symbol d2). Then, the clutch hydraulic pressure Pc supplied to the forward clutch 24 is increased (symbol f2), and the forward clutch 24 is controlled from the open state to the engaged state. Also, as shown at time t7, when the rotor 52 is restrained by the engagement of the forward clutch 24 and the turbine rotation speed Nt and motor rotation speed Nm decrease to 0 [rpm] (symbol g3), the engine rotation speed Ne is reduced (symbol e4). Note that in the capacity coefficient calculation control, the separation clutch 25 is held in the engaged state, and the lock-up clutch 93 is held in the open state.

[0039] [Target Torque Correction Control] Next, we will explain the target torque correction control that corrects the target torque of the engine 12 based on the torque capacity coefficient C. Figure 11 is a flowchart showing an example of the execution procedure for target torque correction control, and Figure 12 is a diagram showing an example of the torque correction coefficient k2. Note that each step of the target torque correction control shown in Figure 11 is a process executed by the processor 80 that constitutes the control system 60. Furthermore, the target torque correction control shown in Figure 11 is a control that is executed by the control system 60 at predetermined intervals after the control system 60 is started.

[0040] As shown by the dashed line Cb in Figure 5, if a torque converter 15 with a torque capacity coefficient C smaller than the reference coefficient Ca is installed, the output torque T2 of the torque converter 15 may be insufficient, potentially reducing the vehicle's starting performance. On the other hand, as shown by the dashed line Cc in Figure 5, if a torque converter 15 with a torque capacity coefficient C larger than the reference coefficient Ca is installed, the output torque T2 of the torque converter 15 may be excessive, potentially inputting excessive torque to the forward clutch 24, etc. Therefore, in order to appropriately control the turbine torque Tt without being affected by variations in the torque capacity coefficient C, the control system 60 performs target torque correction control to correct the target torque of the engine 12 based on the torque capacity coefficient C.

[0041] As shown in Figure 11, in step S30, the torque correction coefficient k2 is set based on the difference Cs of the torque capacity coefficients. That is, as shown in Figure 12, if the difference Cs of the torque capacity coefficients is negative, that is, if the torque capacity coefficient C is smaller than the reference coefficient Ca, the torque correction coefficient k2 is set to be greater than "1". Also, when the difference Cs of the torque capacity coefficients is negative, the torque correction coefficient k2 is set to be larger as the absolute value of the difference Cs increases. On the other hand, if the difference Cs of the torque capacity coefficients is positive, that is, if the torque capacity coefficient C is larger than the reference coefficient Ca, the torque correction coefficient k2 is set to be smaller than "1". Also, when the difference Cs of the torque capacity coefficients is positive, the torque correction coefficient k2 is set to be smaller as the absolute value of the difference Cs increases. Note that, as explained in step S22, the difference Cs of the torque capacity coefficients is the difference obtained by subtracting the reference coefficient Ca from the torque capacity coefficient C.

[0042] As shown in Figure 11, in step S31, the required driving force is set based on the accelerator opening and vehicle speed, and the reference target torque Te1 of the engine 12 is set based on this required driving force. In the following step S32, the corrected target torque Te2 of the engine 12 is calculated by multiplying the reference target torque Te1 by the torque correction coefficient k2. Then, proceeding to step S33, the control system 60 controls the throttle valve 41, injector 42, etc. of the engine 12 based on the corrected target torque Te2. This makes it possible to increase or decrease the engine torque Te according to the difference Cs of the torque capacity coefficient, and to appropriately control the turbine torque Tt output from the torque converter 15.

[0043] Figure 13 shows an example of the changes in engine torque Te and turbine torque Tt. The engine torque Te shown in Figure 13, that is, the engine torque Te output from the crankshaft 31, is the input torque T1 of the torque converter 15. The turbine torque Tt shown in Figure 13, that is, the turbine torque Tt output from the turbine shaft 32, is the output torque T2 of the torque converter 15.

[0044] First, as shown in Figure 12, if the difference Cs of the torque capacity coefficients is a negative value "Csa," that is, if the torque capacity coefficient C is smaller than the reference coefficient Ca, the torque correction coefficient k2 is set to "k2a," which is greater than "1." In this way, when the torque correction coefficient k2 is set to greater than "1," the correction target torque Te2 is set to greater than the reference target torque Te1, as shown by the dashed line La in Figure 13 (arrow α1). In other words, if the torque capacity coefficient C is smaller than the reference coefficient Ca, there is a risk that the turbine torque Tt output from the torque converter 15 will be insufficient, so the input engine torque Te is increased to compensate for the turbine torque Tt.

[0045] Thus, even when the torque capacity coefficient C is smaller than the reference coefficient Ca, the target torque of the engine 12 is corrected to increase it, which allows the turbine torque Tt of the torque converter 15 to be appropriately increased (arrow α2), and the starting performance of the hybrid vehicle 11 can be ensured. Furthermore, when the torque capacity coefficient C is smaller than the reference coefficient Ca, the torque correction coefficient k2 is set to be larger as the absolute value of the difference Cs increases. As a result, the torque difference between the reference target torque Te1 and the corrected target torque Te2 can be increased as the absolute value of the difference Cs increases, and the amount of correction for the target torque of the engine 12 can be increased.

[0046] Furthermore, as shown in Figure 12, if the difference Cs of the torque capacity coefficients is on the positive side, "Csb," that is, if the torque capacity coefficient C is greater than the reference coefficient Ca, the torque correction coefficient k2 is set to "k2b," which is less than "1." In this way, when the torque correction coefficient k2 is set to less than "1," the correction target torque Te2 is set to less than the reference target torque Te1, as shown by the dashed line Lb in Figure 13 (arrow β1). In other words, if the torque capacity coefficient C is greater than the reference coefficient Ca, there is a risk that the turbine torque Tt output from the torque converter 15 will be excessive, so the input engine torque Te is reduced to suppress the turbine torque Tt.

[0047] Thus, even when the torque capacity coefficient C is greater than the reference coefficient Ca, the target torque of the engine 12 is corrected to be lower, which allows the turbine torque Tt of the torque converter 15 to be appropriately reduced (arrow β2), thus avoiding excessive torque input to the forward clutch 24, etc. Furthermore, when the torque capacity coefficient C is greater than the reference coefficient Ca, the torque correction coefficient k2 is set to be larger as the absolute value of the difference Cs increases. As a result, the torque difference between the reference target torque Te1 and the corrected target torque Te2 can be increased as the absolute value of the difference Cs increases, and the amount of correction for the target torque of the engine 12 can be increased.

[0048] The present invention is not limited to the embodiments described above, and it goes without saying that various modifications are possible without departing from the spirit of the invention. For example, in the above description, the control system 60 is configured by four control units, but it is not limited to this. For example, the control system 60 may be configured by one control unit, or by multiple control units. Also, in the above description, the operation of a work terminal in a maintenance factory, etc. was given as an example of a situation in which the execution flag FL1 is set to "1", but it is not limited to this. For example, the control system 60 may set the execution flag FL1 to "1" when a predetermined period of time has elapsed since the previous calculation of the torque capacity coefficient C. In this case, for example, the torque capacity coefficient C can be calculated when the hybrid vehicle 11 is stopped at a traffic light, etc.

[0049] In the above description, the target torque of the engine 12 is corrected based on the torque capacity coefficient C, but this is not the only way. For example, the shift timing of the transmission mechanism 17 may be corrected based on the torque capacity coefficient C, or the target torque of the motor generator 16 may be corrected based on the torque capacity coefficient C. Also, in the above description, a torque correction coefficient k2 is used when correcting the target torque of the engine 12 based on the torque capacity coefficient C, but this is not the only way. For example, a corrected target torque Te2 may be set by adding or subtracting a correction amount to the reference target torque Te1. Also, in the above description, the generated torque Tm is calculated based on the generated current ig, but this is not the only way. For example, the generated torque Tm of the motor generator 16 may be calculated from the detection signal of a torque sensor that detects the torsion of the rotor shaft 53.

[0050] The above explanation states that the forward range is selected as a prerequisite for capacity coefficient calculation control, but it is not limited to this, and the driver may select the reverse range, neutral range, or parking range. Also, the clutch mechanism located between the motor generator 16 and the wheel 22 is described as a forward clutch 24, but it is not limited to this. For example, as the clutch mechanism located between the motor generator 16 and the wheel 22, a reverse clutch which is part of the forward / reverse switching mechanism may be used, or a gear shift clutch provided in the gear shift mechanism 17 may be used. Furthermore, in the illustrated example, a separation clutch 25 is provided between the torque converter 15 and the motor generator 16, but it is not limited to this, and the separation clutch 25 may be removed from the powertrain 14 and the turbine shaft 32 and rotor shaft 53 may be directly connected to each other. [Explanation of Symbols]

[0051] 10 Vehicle control devices 11 Hybrid Vehicles 12 Engines 15 Torque Converter 16 Motor Generator 22 wheels 24. Forward clutch (clutch mechanism) 30 Power transmission path 60 Control Systems 80 processors 81 Main memory (memory) 93 Lock-up clutch Tm (torque of power generation) T1 Input Torque T2 Output Torque N1 Input rotation speed η efficiency C Torque capacity coefficient Ca reference coefficient Cs difference Te1 Reference Target Torque (Target Torque) Te2 Correction Target Torque (Target Torque)

Claims

1. A vehicle control device used in hybrid vehicles, An engine connected to the wheels via a power transmission path, A motor generator provided in the power transmission path, A torque converter is provided in the power transmission path and is located between the engine and the motor generator, A clutch mechanism provided in the power transmission path and located between the motor generator and the wheel, A control system comprising a processor and memory connected to each other in a manner that enables communication between them, for controlling the engine, the motor generator, the torque converter, and the clutch mechanism, It has, The control system is With the clutch mechanism released, the engine controlled to be running, and the motor generator controlled to be generating power, the generated torque of the motor generator is calculated. The control system is Based on the output torque of the torque converter calculated from the generated torque, the torque capacity coefficient of the torque converter is calculated. Vehicle control device.

2. In the vehicle control device according to claim 1, The control system is Based on the efficiency and output torque of the torque converter, the input torque of the torque converter is calculated. The torque capacity coefficient is calculated based on the input rotational speed and input torque of the torque converter. Vehicle control device.

3. In the vehicle control device according to claim 1, The control system is If the torque capacity coefficient is greater than the reference coefficient, the target torque of the engine is corrected to be lower. If the torque capacity coefficient is smaller than the reference coefficient, the target torque of the engine is corrected to increase it. Vehicle control device.

4. In the vehicle control device according to claim 3, The control system is The larger the absolute value of the difference between the torque capacity coefficient and the reference coefficient, the larger the correction amount for the target torque is set. Vehicle control device.

5. In the vehicle control device according to claim 1, The control system is With the clutch mechanism released, the engine controlled to be running, the lock-up clutch of the torque converter released, and the motor generator controlled to be generating power, the generated torque of the motor generator is calculated. Vehicle control device.

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