JP2009228779A - Control device for vehicle driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a vehicle driving device, provided with a variable capacity torque converter, increasing a torque ratio, lowering a capacity coefficient, and sufficiently improving power performance of a vehicle. <P>SOLUTION: This control device includes a capacity coefficient control means 140 changing the capacity coefficient C of the torque converter 6 according to the gear ratio of an automatic transmission 8 in order to acquire necessary driving force. Therefore, an engine 8 is operated within the optimum operation area. That is, the capacity coefficient C of the torque converter 6 is changed with respect to the necessary driving force, thereby changing the operation area of the engine 9. Accordingly, for example, for aiming at fuel economy-oriented travelling, the operation area of the engine 9 can be operated in an area having excellent fuel economy characteristics. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle drive device including a torque converter capable of amplifying torque via a fluid, and more particularly, to a vehicle drive device including a variable capacity torque converter capable of changing a capacity coefficient of the torque converter by an electric motor. The present invention relates to a control device.

  A torque converter having a pump impeller, a turbine impeller, and a stator impeller rotatably disposed between the turbine impeller and the pump impeller is well known. In such a conventional torque converter, the stator wheel is connected to the non-rotating member via the one-way clutch, and does not have variable capacity characteristics. Generally, the fluid characteristics of a torque converter are desired to have a high capacity (capacity coefficient) when fuel-oriented, but in the above conventional structure, depending on the shape of the pump impeller, turbine impeller, and stator impeller Since they are uniquely determined, the same fluid characteristics are obtained regardless of the running pattern, and there is a limit to improving the fuel efficiency and power performance at the same time.

  For example, when the capacity coefficient of the torque converter is high, the rotational speed of the pump impeller, that is, the rotational speed difference between the rotational speed of the driving source and the rotational speed of the turbine impeller is small. For example, the driver depresses the accelerator pedal from a steady state. When acceleration is attempted, if the downshift is not performed, the rotational speed of the turbine impeller is not increased, so that the driving force cannot be generated quickly. Thus, when a high-capacity torque converter is employed, it is necessary to operate the drive source in a region of high rotation and low load even during steady running so that torque is easily generated when depressed. On the other hand, when the capacity coefficient of the torque converter is low, the rotational speed difference between the rotational speed of the pump impeller and the rotational speed of the turbine impeller is large, so that the response when the accelerator pedal is depressed is improved. However, since the rotational speed difference between the rotational speed of the pump impeller and the rotational speed of the turbine impeller increases even during steady running, the internal loss of the torque converter increases.

  On the other hand, as disclosed in Patent Document 1, a brake means is provided between the stator impeller and the non-rotating member, and a variable capacity torque in which the capacity is made variable by adjusting the braking torque of the brake means. Converters have been proposed. According to this, it becomes possible to change the torque ratio and capacity coefficient of the torque converter steplessly or in multiple steps by adjusting the braking torque by the brake means, and the optimum torque ratio and The capacity coefficient can be set, and the running performance of the vehicle can be improved.

JP-A-1-169170

  However, in the conventional variable displacement torque converter, the rotation of the stator impeller is only controlled in the negative rotation direction opposite to the rotation direction of the pump impeller, and the torque ratio obtained thereby is reduced. There is a limit to the upper limit and the lower limit of the capacity coefficient, and the torque ratio of the torque converter cannot be increased sufficiently according to the driving conditions and driving conditions, and the capacity coefficient cannot be changed low, so that the power performance of the vehicle is sufficiently I could not increase it.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to increase the torque ratio and change the capacity coefficient to a low level, thereby sufficiently improving the power performance of the vehicle. An object of the present invention is to provide a control device for a vehicle drive device provided with a variable capacity type torque converter.

  Thus, as a result of various studies conducted by the inventors against the background described above, the stator impeller is rotated in the positive direction, which is the rotational direction of the pump impeller, using an electric motor that is a power source separate from the drive source of the vehicle. It was found that a high torque ratio and a low capacity coefficient can be obtained when driven actively in the direction. Thus, the stator impeller is rotated (driven) in the positive rotation direction, which is the rotation direction of the pump impeller, and rotated in the negative rotation direction opposite to the rotation direction of the pump impeller (braking, regeneration) using an electric motor. As a result, the change range of the torque ratio and the capacity coefficient becomes wider as compared with the conventional case, so that the fuel efficiency and power performance of the vehicle can be greatly improved. Further, the inventors have found a control method that enables the drive source to operate in a region having excellent fuel consumption characteristics by controlling the capacity coefficient of the torque converter.

  That is, in order to achieve the above object, the gist of the invention according to claim 1 is that (a) the pump impeller, the turbine impeller, and the turbine impeller can be rotated between the turbine impeller and the pump impeller. A vehicle drive device that includes a torque converter having a stator impeller disposed on the vehicle and an automatic transmission whose gear ratio is automatically changed, and transmits power output from a drive source to drive wheels. (B) an electric motor capable of changing the capacity coefficient of the torque converter by driving or braking the stator impeller, and (c) a gear ratio of the automatic transmission so as to obtain a required driving force. And a capacity coefficient control means for changing the capacity coefficient of the torque converter in response.

  According to a second aspect of the present invention, there is provided a control device for a vehicle drive device according to the first aspect, wherein: (a) the drive source is an internal combustion engine; and (b) a preset shift diagram. Shift control means for stepwise switching the gear ratio of the automatic transmission based on the vehicle speed and the accelerator opening for manipulating the output of the internal combustion engine, and (c) the capacity coefficient control means includes the necessary driving force and When the sum of the marginal driving force set in advance exceeds the maximum driving force obtained at the gear ratio determined by the shift diagram, the capacity coefficient of the torque converter is set in advance as the required driving force. It is characterized in that the sum of the marginal driving force and the marginal driving force is reduced as compared with the case where the sum does not exceed the maximum driving force obtained at the gear ratio determined by the shift diagram.

  According to a third aspect of the present invention, there is provided a control device for a vehicle drive device according to the first aspect, wherein the capacity coefficient control means is configured so that the drive force of the vehicle becomes a required drive force. The capacity coefficient of the converter is adjusted.

  According to a fourth aspect of the present invention, there is provided the control device for a vehicle drive device according to the second or third aspect, wherein (a) the sum of the necessary drive force and the margin drive force is the maximum drive. When the maximum driving force after assistance assisted by an increase in the torque ratio of the torque converter, that is, the sum of the maximum driving force before assistance and the auxiliary driving force due to an increase in the torque ratio of the torque converter is not exceeded. A first fuel consumption amount calculating means for calculating a fuel consumption amount when the capacity coefficient is controlled by the capacity coefficient control means when the transmission gear ratio is set, and (b) a turbine impeller and a pump of the torque converter A second fuel consumption amount is calculated when the minimum gear ratio is selected from among the gear ratios capable of obtaining the required driving force when the impeller is directly connected to the impeller by a lock-up clutch. And (c) based on a comparison result between the fuel consumption calculated by the first fuel consumption calculation means and the fuel consumption calculated by the second fuel consumption calculation means, And a lockup clutch operating state selection unit that selects whether the torque coefficient is controlled by the capacity coefficient control unit or the direct coupling state by the lockup clutch.

  A gist of the invention according to claim 5 is that, in the control device for a vehicle drive device according to any one of claims 1 to 4, the sum of the required drive force and the margin drive force is a current gear ratio. And the maximum driving force after assistance that is assisted by an increase in the torque ratio of the torque converter, that is, the maximum driving force before assistance and the auxiliary driving force that results from an increase in the torque ratio of the torque converter, Driving force determining means for determining whether or not the sum does not exceed the sum, the shift control means is configured so that the sum of the required driving force and the marginal driving force is determined by the driving force determining means at the maximum speed at the current gear ratio. When it is determined that the driving force is exceeded and the maximum driving force after assistance assisted by the torque ratio increase of the torque converter is exceeded, a downshift that increases the speed ratio from the current speed ratio is performed. And characterized in that.

  According to a sixth aspect of the present invention, in the control device for a vehicle drive device according to any one of the first to fifth aspects, it is determined whether or not the vehicle is directed to fuel-efficient traveling. Fuel capacity-oriented travel determination means, and the capacity coefficient control means determines the capacity coefficient of the torque converter so that the required driving force can be obtained when the fuel efficiency-oriented travel determination means determines that the fuel efficiency-oriented travel is being performed. It is a thing to change.

  The gist of the invention according to claim 7 is that, in the control device for a vehicle drive device according to claim 6, when the shift control means is determined not to be fuel mileage oriented by the fuel consumption oriented travel judging means. Is a shift diagram in which the shift line is located on the higher vehicle speed side than that of the shift diagram, and based on the vehicle speed and the accelerator opening for operating the output of the internal combustion engine, the gear ratio of the automatic transmission Is characterized in that it is switched step by step.

  According to the control device for a vehicle drive device of the first aspect of the present invention, the pump impeller, the turbine impeller, and the stator impeller that is rotatably disposed between the turbine impeller and the pump impeller. And a motor for driving the stator impeller, the stator impeller is rotated using the electric motor in the positive rotation direction that is the rotation direction of the pump impeller and the negative direction opposite to the rotation direction of the pump impeller. By rotating in the rotational direction, the change range of the torque ratio and the capacity coefficient becomes wider compared to the conventional case, so that the fuel efficiency and power performance of the vehicle can be greatly improved.

  In addition, since the capacity coefficient control means for changing the capacity coefficient of the torque converter according to the gear ratio of the automatic transmission is provided so as to obtain the required driving force, the drive source can be operated in the optimum operating region. . That is, it is possible to change the operating region of the drive source by changing the capacity coefficient of the torque converter with respect to the required driving force. Thereby, for example, if fuel efficiency-oriented running is performed, the drive source can be operated in a driving region with excellent fuel consumption characteristics.

  According to the control device for a vehicle drive device of the invention according to claim 2, the capacity coefficient control means is a gear shift in which a sum of the required drive force and a preset margin drive force is determined by the shift diagram. When the maximum driving force obtained by the ratio is exceeded, the capacity coefficient of the torque converter is obtained at the gear ratio determined by the shift diagram in which the sum of the required driving force and a preset margin driving force is obtained. This is lower than when the maximum driving force is not exceeded. In this way, since the torque ratio is increased, it is possible to obtain a driving force exceeding the maximum driving force even in a driving source operating region where it is difficult to obtain a driving force exceeding the maximum driving force. it can. Thereby, the area width of the operation region of the drive source can be widened, and the drive source can be operated in an operation region with excellent fuel consumption characteristics, for example.

  According to the control device for a vehicle drive device of the invention of claim 3, the capacity coefficient control means adjusts the capacity coefficient of the torque converter so that the drive force of the vehicle becomes the required drive force. The necessary driving force can be obtained even when the driving source is operated in an operating region having excellent fuel consumption characteristics.

  According to the control apparatus for a vehicle drive device of the invention according to claim 4, the fuel consumption calculated by the first fuel consumption calculation means and the fuel consumption calculated by the second fuel consumption calculation means. Lockup clutch operating state selection means for selecting whether the torque converter is in a state in which the capacity coefficient is controlled by the capacity coefficient control means or in a directly connected state by the lockup clutch based on the comparison result with the amount Therefore, the fuel consumption characteristic can be improved by switching to the control with the smaller fuel consumption.

  According to the control device for a vehicle drive device of the invention according to claim 5, the shift control means is configured such that the sum of the required drive force and the margin drive force is the current gear ratio by the drive force determining means. When it is judged that the maximum driving force is exceeded and the maximum driving force after assistance that is assisted by the torque ratio increase of the torque converter is exceeded, a downshift that increases the gear ratio from the current gear ratio is performed. Therefore, a driving force that cannot be obtained by increasing the torque ratio of the torque converter can be obtained.

  According to a control device for a vehicle drive device of a sixth aspect of the present invention, the vehicle includes fuel efficiency-oriented travel determination means for determining whether or not the vehicle is oriented for fuel efficiency-oriented travel, the capacity coefficient control means being When the fuel efficiency-oriented travel determination means determines that the fuel efficiency-oriented travel is being performed, the capacity coefficient of the torque converter is changed so that the required driving force is obtained, so that the fuel efficiency-oriented travel is selected. In addition, the necessary driving force can be generated in a state where the driving source is operated in an operating region having excellent fuel consumption characteristics.

  According to the control device for a vehicle drive device of the invention of claim 7, when the shift control means determines that the fuel consumption direction is not fuel-oriented by the fuel consumption-oriented travel determination means, the shift line is changed to the speed change gear. The shift ratio of the automatic transmission is switched stepwise based on the vehicle speed and the accelerator opening for manipulating the output of the internal combustion engine, using a shift diagram positioned on the higher vehicle speed side than that of the diagram. Therefore, it is possible to carry out traveling with emphasis on power performance.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a skeleton diagram of a vehicle drive device 7 to which a torque converter 6 (variable capacity type torque converter) according to an embodiment of the present invention is applied. This vehicle drive device 7 has a vertical-type automatic transmission 8 and is suitably employed in an FR (front engine / rear drive) type vehicle, and an engine as a driving force source for traveling. 9 is provided. The output of the engine 9 composed of an internal combustion engine is driven right and left via a torque converter 6 that functions as a fluid transmission device, an automatic transmission 8, a differential gear device (final reduction gear) (not shown), a pair of axles, and the like. It is transmitted to the wheel 13 (see FIG. 8). The engine 9 corresponds to the drive source of the present invention.

  The torque converter 6 is connected to a crankshaft of the engine 9 and is driven to rotate from the engine 9 to generate a fluid flow due to the flow of hydraulic oil in the torque converter 6, and the automatic transmission 8. A turbine impeller 6t connected to the input shaft 22 and rotated by receiving a fluid flow from the pump impeller 6p, and a stator rotatably arranged in the fluid flow from the turbine impeller 6t to the pump impeller 6p. The impeller 6s is provided to transmit power through hydraulic oil (fluid).

  Further, a lockup clutch L / C is provided between the pump impeller 6p and the turbine impeller 6t. The lockup clutch L / C is engaged and slipped by a hydraulic control circuit 30 described later. Alternatively, the disengaged state is controlled, and the pump impeller 6p and the turbine impeller 6t are integrally rotated by being in a fully engaged state, that is, the crankshaft of the engine 9 and the input shaft 22 are mutually connected. It is supposed to be directly connected.

  The vehicle drive device 7 selectively connects (intermittently) the electric motor (electric motor) 10 for rotationally driving the stator impeller 6s of the torque converter 6 and the electric motor 10 and the stator impeller 6s. ), And a brake Bs that selectively connects (intermitts) between the stator impeller 6s and a transmission case (hereinafter referred to as a case) 11 that is a non-rotating member. The electric motor 10 corresponds to the electric motor of the present invention.

The electric motor 10 is configured to control the rotational speed in the positive rotational direction, which is the rotational direction of the pump impeller 6p of the stator impeller 6s, by driving. At this time, for example, as shown in FIG. 2A, the stator impeller 6s is proportional to the magnitude of the drive current I _D supplied to the electric motor 10 for rotational driving from an electronic control device 78 described later. drive torque T _D of the positive rotation direction is provided. The electric motor 10 controls the rotational speed of the stator impeller 6s in the negative rotation direction by driving. At this time, the stator wheel 6s, for example, drive torque T _D of the negative rotation direction is applied which is proportional to the magnitude of the drive current I _D supplied to the electric motor 10.

The electric motor 10 also controls the rotational speed in the negative rotational direction opposite to the rotational direction of the pump impeller 6p of the stator impeller 6s by braking (regeneration). At this time, the stator wheel 6s, for example, the negative rotation which is proportional to the magnitude of the generated current I _G to be supplied i.e. accumulated in such a power storage device 50, for example, provided in the vehicle as shown in FIG. 2 (b) direction of the load torque i.e. braking (regenerative) torque T _B is given.

The clutch Cs and the brake Bs are hydraulic friction engagement devices including a hydraulic actuator and a multi-plate clutch or brake that is frictionally engaged or released by the hydraulic pressure supplied to the hydraulic actuator. The stator impeller 6s is fixed to the case 11 and made non-rotatable by the engagement of the brake Bs. Further, the stator impeller 6 s is relatively positive with respect to the pump impeller 6 p that rotates in the positive rotation direction even by slip generated by adjusting the degree of engagement of the brake Bs, that is, the engagement pressure. It can be rotated in the negative rotation direction opposite to the rotation direction. At this time, the stator wheel 6s, the negative direction of rotation of the load torque i.e. brake torque T _B is given, for example increasing with the engaging pressure is increased. In addition, the stator wheel 6s, has become by clutch Cs is engaged to the drive torque T _D or brake torque T _B by the electric motor 10 is transmitted as it is, also, the engagement of the clutch Cs the slip degree i.e. engagement pressure is generated by being adjusted according to the size of the engaging pressure so that the transmission ratio of the drive torque T _D or brake torque T _B is changed.

  The automatic transmission 8 includes a first transmission portion 14 mainly composed of a double pinion type first planetary gear device 12 and a single pinion type second in a case 11 as a non-rotating member attached to a vehicle body. The planetary gear unit 16 and the second pinion type third planetary gear unit 18 and the second transmission unit 20 mainly composed of the planetary gear unit 16 and a second pinion type third planetary gear unit 18 are arranged on a common axis, and the output shaft 24 is shifted by rotating the input shaft 22. Output from. The input shaft 22 is also a turbine shaft of the torque converter 6 that is rotationally driven by power from the engine 9 that is a power source for traveling. The torque converter 6 and the automatic transmission 8 are configured substantially symmetrically with respect to their axis, and the lower half of these axes is omitted in the skeleton diagram of FIG.

  The first planetary gear unit 12 includes a sun gear S1, a plurality of pairs of pinion gears P1 that mesh with each other, a carrier CA1 that supports the pinion gears P1 so as to rotate and revolve, and a ring gear R1 that meshes with the sun gear S1 via the pinion gears P1. The second planetary gear device 16 includes a sun gear S2, a pinion gear P2, a carrier CA2 that supports the pinion gear P2 so as to be capable of rotating and revolving, and a ring gear R2 that meshes with the sun gear S2 via the pinion gear P2. The third planetary gear unit 18 meshes with the sun gear S3 via the sun gear S3, a plurality of pairs of pinion gears P2 and P3 that mesh with each other, a carrier CA3 that supports the pinion gears P2 and P3 so as to rotate and revolve, and pinion gears P2 and P3. A ring gear R3 is provided.

  In FIG. 1, the clutches C1 to C4 and the brakes B1 and B2 include a hydraulic actuator and a multi-plate clutch or brake that is engaged or released by the hydraulic pressure supplied to the hydraulic actuator, similarly to the clutch Cs and the brake Bs. In the hydraulic friction engagement device, the first rotation element RM1 (sun gear S2) is selectively connected to the case 11 via the first brake B1 and stopped rotating, and the intermediate output is output via the third clutch C3. It is selectively connected to the ring gear R1 (that is, the second intermediate output path PA2) of the first planetary gear device 12 that is a member, and further, the carrier CA1 (that is, the first intermediate gear) of the first planetary gear device 12 via the fourth clutch C4. It is selectively connected to the indirect path PA1b) of the output path PA1.

  The second rotating element RM2 (carriers CA2 and CA3) is selectively connected to the case 11 via the second brake B2 and stopped rotating, and the input shaft 22 (that is, the first intermediate) via the second clutch C2. A direct connection path PA1a) of the output path PA1 is selectively connected. The third rotating element RM3 (ring gears R2 and R3) is integrally connected to the output shaft 24 to output rotation. The fourth rotation element RM4 (sun gear S3) is connected to the ring gear R1 via the first clutch C1. A one-way clutch F1 that prevents the reverse rotation while allowing the second rotation element RM2 to rotate forward (the same rotation direction as the input shaft 22) is provided between the second rotation element RM2 and the case 11. It is provided in parallel with B2.

FIG. 3 is a chart for explaining the operating state of each engaging element when each gear position is established in the automatic transmission 8. “◯” indicates the engaged state, and “(○)” indicates only when the engine is braked. The engaged state and the blank indicate the released state. As shown in FIG. 3, in the automatic transmission 8 of the present embodiment, each of the engagement devices, that is, a plurality of hydraulic friction engagement devices (clutch C1 to C4, brakes B1 and B2) are selectively engaged. As a result, a plurality of shift stages including eight forward speeds with different speed ratios (= input shaft rotational speed N _{IN of the} automatic transmission 8 / output shaft rotational speed N _{OUT of the} automatic transmission 8) are established. Note that the gear ratio of each gear stage is appropriately determined by the gear ratios ρ1, ρ2, and ρ3 of the first planetary gear device 12, the second planetary gear device 16, and the third planetary gear device 18.

FIG. 4 is a block diagram illustrating a control system provided in the vehicle for controlling the engine 9, the automatic transmission 8, the torque converter 6 and the like of FIG. The electronic control unit 78, an engine signal indicative of the engine rotational speed N _E from the rotational speed sensor 80, a turbine rotational speed N _T that is, the signal indicating the input shaft speed N _IN of the turbine speed sensor 82, a stator rotation speed sensor signal of the stator rotational speed N _S of the 83, a signal indicating the intake air amount Q _a from the intake air amount sensor 84, a signal indicating the intake air temperature T _a from the intake air temperature sensor 86, a vehicle speed from the vehicle speed sensor 88 V that is, the signal indicating the output shaft rotational speed N _OUT, a signal indicating a throttle valve opening theta _TH from a throttle sensor 90, a signal indicating the cooling water temperature T _W from the cooling water temperature sensor 92, the hydraulic control circuit from the oil temperature sensor 94 signal indicating the 30 working oil temperature T _oIL, and indicating the operation amount a _CC of the accelerator operation member such as an accelerator pedal 98 from an accelerator operation amount sensor 96 No., so that the signal indicating the presence or absence of the operation of the foot brake 102 is a service brake from the foot brake switch 100, such as a signal indicative of the lever position (operating position) P _SH of the shift lever 106 from the lever position sensor 104 is supplied It has become.

  The electronic control unit 78 includes a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and follows a program stored in the ROM in advance. Each input signal is processed, and a signal, that is, an output signal is output to the electronic throttle valve 108, the fuel injection device 110, the ignition device 112, the linear solenoid valve of the hydraulic control circuit 30, or the electric motor 10, etc. Yes. The electronic control device 78 performs output control of the engine 9 and rotation control of the stator 6s of the torque converter 6 by performing such input / output signal processing. And for shift control.

  In this embodiment, the output control of the engine 9 is performed by the electronic throttle valve 108, the fuel injection device 110, the ignition device 112, and the like.

The shift control of the automatic transmission 8 is performed by the hydraulic control circuit 30, for example, based on the actual throttle valve opening θ _TH and the vehicle speed V from the shift map (shift map) stored in advance, the shift of the automatic transmission 8. The gear stage to be determined is determined, and the clutches C1 to C4 and the brakes B1 and B2 are disengaged in accordance with the operation table shown in FIG. 3 so as to establish the determined gear stage.

The rotation control of the stator impeller 6 s of the torque converter 6 is performed by the clutch Cs and the brake Bs of the hydraulic control circuit 30 or the electric motor 10. Specifically, the rotation of the stator impeller 6s is controlled by the magnitude of the drive current _ID supplied from the inverter (not shown) to the electric motor 10 in accordance with a command from the electronic control device 78 in a state where the clutch Cs is engaged. This is executed by appropriately adjusting the driving torque T _D proportional to the driving torque T _D or, for example, the braking torque T _B proportional to the magnitude of the generated current I _G output from the electric motor 10.

  Here, in the torque converter 6 of the present embodiment, the hydraulic oil that sticks to the outer peripheral side due to the centrifugal force is pump impeller 6p, turbine impeller 6t, starter along the streamline FL in FIG. It circulates in order of the impeller 6s. As shown in FIG. 5, the pump impeller 6p, the turbine impeller 6t, and the stator impeller 6s include a plurality of blades that are spaced apart from each other in the circumferential direction. FIG. 5 shows the shape of the blades along the flow line FL of hydraulic oil in the torque converter 6 in each impeller. The hydraulic fluid that is made to flow by being given energy by the blades of the pump impeller 6p acts on the blades of the turbine impeller 6t to rotate the turbine impeller 6t. In the converter region, the hydraulic oil that has passed through the turbine impeller 6t hits the blades of the stator impeller 6s and is redirected to the pump impeller 6p. When hydraulic oil hits the blades of the stator impeller 6s to change the direction, reaction torque is generated in the stator impeller 6s. The reaction torque corresponds to the direction change amount (angle) of the hydraulic oil and corresponds to the magnitude of a torque ratio t described later.

  According to the definition of angular momentum, the torque T [N · m] that each impeller (pump impeller 6p, turbine impeller 6t, and stator impeller 6s) gives to the hydraulic fluid (fluid) is expressed by the following equation (1). It is expressed as follows.

T = (γ / g) × Q × Δ (r × v _U ) (1)

In equation (1), γ is the specific weight of the hydraulic oil in the torque converter 6 [kg / m ³ ], g is the acceleration of gravity [m / s ² ], and Q is the volume flow rate of the hydraulic oil [m ³ / s]. , Δ (r × v _U ) is the difference between the moments r × v _U [m ² / s] of the absolute speeds of the hydraulic oil at the outlet and inlet of the fluid flow in each impeller.

From the above equation (1), the torque T ₁ [N · m] given to the hydraulic oil by the pump impeller 6p, the torque T ₂ [N · m] given to the hydraulic oil by the turbine impeller 6t, and the stator impeller 6s are actuated. Torque T ₃ [N · m] applied to the oil is expressed by the following equations (2) to (4). In the formula (2) to (4), T _P is pump torque [N · m], ie, the engine torque, T _T is turbine torque [N · m] that is, the output torque, T _S is the reaction torque of the stator wheel 6s When the direction of the hydraulic oil flow is changed by the stator impeller 6s, that is, the stator impeller 6s, the stator impeller 6s acts in the positive rotation direction that is the rotational direction of the pump impeller 6p. Torque.

T ₁ = _TP = (γ / g) × Q × (V _UP × r ₂ −V _US × r ₁ ) (2)
T ₂ = −T _T = (γ / g) × Q × (V _UT × r ₃ −V _UP × r ₂ ) (3)
T ₃ = T _S = (γ / g) × Q × (V _US × r ₁ −V _UT × r ₃ ) (4)

In equations (2) to (4), r ₁ is the rotational axis at the fluid flow outlet bp of the pump impeller 6 p and the fluid flow inlet at of the turbine impeller 6 t, that is, the input shaft (turbine shaft) of the automatic transmission 8. distance from 22 [m], r ₂ is a distance from the axis of rotation at the inlet as the fluid flow outlet bt and stator wheel 6s of fluid flow turbine wheel 6t [m], r ₃ is the stator wheel 6s The distance [m] from the rotation axis at the fluid flow outlet bs and the fluid flow inlet ap of the pump impeller 6p. In the equations (2) to (4), V _UP is the circumferential speed [m / s] of the absolute speed of the pump impeller 6p, and V _UT is the circumferential speed of the absolute speed of the turbine impeller 6t [ m / s], V _US is the circumferential speed [m / s] of the absolute speed of the stator impeller 6s.

Since T ₁ + T ₂ + T ₃ = 0 (zero) holds from the equations (2) to (4), the pump torque T _P , the turbine torque T _T , and the stator torque T _S are expressed as the following equation (5). Is done. In other words, the torque increase of the turbine torque T _T with respect to the pump torque T _P in the torque converter 6 corresponds to the stator torque T _S.

T _T = T _P + T _S (5)

Here, the torque converter 6 of the present embodiment, since the reaction force of the stator wheel 6s is increased or decreased by the driving torque T _D or brake torque T _B is adjusted by the rotation control of the electric motor 10 described above, the turbine blade The output torque output from the vehicle can be increased or decreased with respect to the output torque obtained by a conventional constant capacity torque converter.

6 and 7 are diagrams showing the characteristics of the torque converter 6 of the present embodiment showing the above-described contents. FIG. 6 shows the rotational speed ratio between the turbine rotational speed N _T [rpm] of the turbine impeller 6t and the pump rotational speed N _P [rpm] of the pump impeller 6p, that is, the speed ratio e (= N _T / N _P ). FIG. 7 is a diagram showing a torque ratio (torque amplification factor) t (= T _T / T _P ) between the turbine torque T _T and the pump torque T _P, and FIG. 7 shows the speed ratio e (= N _T / N _P ). FIG. 4 is a diagram showing a capacity coefficient C (= T _P / N _P ² ) [N · m / rpm ² ].

6 and 7, the braking torque T _B is by or brake Bs is adjusted to a predetermined value are engaged, the stator wheel 6s is fixed to the case 11, the base line shown in solid line in FIG. 6 As indicated by Bt, torque is transmitted at a predetermined torque ratio t determined by design as in a conventional constant-capacity torque converter. Note that the capacity coefficient C of the torque converter 6 at this time is as indicated by a baseline BC shown by a solid line in FIG.

Further, when the clutch Cs is rotated drive torque T _D by the electric motor 10 is adjusted to a predetermined value the stator wheel 6s in the same rotational direction as the pump impeller 6p while being engaged properly engaged, the stator torque T _{As S} increases, torque is transmitted at a torque ratio t larger than that obtained with a conventional constant-capacity torque converter as shown by the long chain line in FIG. 6 indicating normal rotation of the stator. The capacity coefficient C of the torque converter 6 at this time is like a long chain line indicating the normal rotation of the stator in FIG. The torque ratio t and the capacity coefficient C may be the same speed ratio e, Figure as indicated by the arrow a, d of FIG. 6 and FIG. 7 by the drive torque T _D is further increased or decreased by the electric motor 10 It is appropriately set within the range from the base line Bt of 6 to the long chain line indicating the normal rotation of the stator or from the base line BC of FIG.

Further, when the stator torque T _S is made zero by the clutch Cs and the brake Bs is released in increased is not torque ratio t = 1 made of the torque as shown by a chain line of the stator free 6 Torque is transmitted. As a result, the torque converter 6 operates as a fluid coupling. The capacity coefficient C of the torque converter 6 at this time is as indicated by a chain line indicating stator free in FIG.

Further, braking (regenerative) When the torque T _B is the brake Bs engagement pressure for or brake Bs is adjusted to a predetermined value is adjusted to a predetermined value is caused to slip, the stator torque T _S is the stator wheel 6s As shown by the short chain line shown by the stator motor regeneration in FIG. 6, torque is transmitted at a torque ratio t smaller than that obtained by a conventional constant-capacity torque converter. The capacity coefficient C of the torque converter 6 at this time is as shown by a short chain line shown by stator motor regeneration in FIG. The torque ratio t and the capacity coefficient C may be the same speed ratio e, braking (regenerative) torque T _B or arrow b in FIG. 6 and FIG. 7 by the engagement pressure of the brake Bs is further increased or decreased, As shown in c, it is appropriately set in the range from the base line Bt or BC to the one-dot chain line shown in a stator-free manner.

  That is, the electric motor 10 in this embodiment increases the torque ratio t by controlling the rotation of the stator impeller 6s in the positive rotation direction that is the rotation direction of the pump impeller 6p. Further, the electric motor 10 in this embodiment reduces the torque ratio t by controlling the rotation of the stator impeller 6s in the negative rotation direction opposite to the rotation direction of the pump impeller 6p by braking (regeneration). is there. Furthermore, the brake Bs in the present embodiment reduces the torque ratio t by controlling the rotation of the stator impeller 6s in the negative rotation direction opposite to the rotation direction of the pump impeller 6p by the slip.

  FIG. 8 is a functional block diagram for explaining a main part of the control function by the electronic control unit 78. In FIG. 8, the shift control means 118 functions as a shift control means for shifting the automatic transmission 8. The shift control means 118 switches the gear ratio of the automatic transmission 8 step by step based on the accelerator speed Acc for operating the vehicle speed V and the output of the engine 9 from the shift diagram stored in the storage means 119 in advance.

  The engine drive state determination means 120 determines whether or not the engine 9 is driven based on, for example, an output signal from the engine output control device 121. When it is determined by the engine drive state determination means 120 that the engine 9 is being driven, the fuel efficiency-oriented travel determination means 122 determines whether the low fuel consumption mode switch provided in the driver's seat has been selected by the driver, for example. Based on the above, it is determined whether or not the driver is aiming at fuel-efficient driving. Note that the fuel economy-oriented running may be automatically determined based not only on the selection of the low fuel consumption mode switch but also based on, for example, the operation frequency of the accelerator pedal or the depression speed of the driver. Here, when it is determined by the fuel consumption oriented travel determination means 122 that the fuel consumption direction is not oriented, a shift diagram in which the shift line is located on the higher vehicle speed side than that of the shift diagram applied at the time of fuel efficiency orientation is applied, and the vehicle speed V And the gear ratio of the automatic transmission 8 are switched stepwise based on the accelerator opening Acc.

  The required driving force calculation means 124 calculates the required driving force required for driving the vehicle based on a driving force map composed of the accelerator opening Acc and the vehicle speed V or an arithmetic expression. Further, the margin driving force calculation unit 125 calculates the margin driving force based on a margin driving force map that is preliminarily stored in the storage unit 119 and configured from the accelerator opening Acc and the vehicle speed V, for example. The marginal driving force is the difference between the driving force that exceeds the driving force necessary for maintaining the vehicle at a constant speed, that is, the maximum driving force and the running resistance (required driving force). The larger the value, the stronger the acceleration.

  The driving force determination means 126 is configured such that the sum of the required driving force calculated by the required driving force calculation means 124 and the margin driving force calculated by the margin driving force calculation means 125 is the maximum in the current gear ratio of the automatic transmission 8. It exceeds the driving force and does not exceed the sum of the maximum driving force after assistance assisted by the torque ratio increase of the torque converter 6, that is, the sum of the maximum driving force before assistance and the auxiliary driving force due to the torque ratio increase of the torque converter 6. It is determined whether or not. The maximum driving force is experimentally determined in advance according to the gear ratio of the automatic transmission 8, and the maximum driving force after assistance is also experimentally determined in advance.

  Here, the sum of the required driving force and the marginal driving force exceeds the maximum driving force at the current gear ratio by the driving force determining means 126 and the auxiliary force that is assisted by the torque ratio increase of the torque converter 6 is added. If it is determined that the maximum driving force is exceeded, the shift control means 118 performs a downshift that increases the gear ratio from the current gear ratio.

  The sum of the necessary driving force and the marginal driving force exceeds the maximum driving force at the current gear ratio by the driving force determining means 126, and the maximum driving force after assistance that is assisted by the increase in the torque ratio of the torque converter 6 When the variable capacity maximum gear stage calculating means 130 is determined to exceed, the sum of the required driving force and the marginal driving force exceeds the maximum driving force, but is assisted by an increase in the torque ratio t of the torque converter 6. The automatic transmission 8 has a minimum speed ratio within a range that does not exceed the maximum driving force after assistance, that is, the sum of the maximum driving force before assistance and the auxiliary driving force due to the increase in the torque ratio of the torque converter 6. Calculate the maximum gear (high-speed gear). The auxiliary driving force due to the increase in the torque ratio of the torque converter 6 is experimentally obtained in advance for each gear stage (speed ratio) of the automatic transmission 8 and stored in the storage means 119.

  The first fuel consumption amount calculating means 132 is a variable of the torque converter 6 by the capacity coefficient control means 140 described later when the automatic transmission 8 is set to the highest gear stage calculated by the variable capacity maximum gear stage calculating means 130. A fuel consumption amount FA of the engine 9 at the time of capacity control is calculated. The fuel consumption amount FA is a consumption amount necessary for generating the necessary driving force when the automatic transmission 8 is at the maximum gear position, and the driving state of the engine 9 for generating the necessary driving force is calculated. Then, the fuel consumption amount FA is calculated based on the fuel consumption map of the engine 9 using the accelerator opening degree Acc and the engine rotational speed NE, which are experimentally obtained in advance, as parameters.

  Further, the sum of the required driving force and the marginal driving force exceeds the maximum driving force at the current gear ratio by the driving force determination means 126, and the maximum after assistance that is assisted by the increase in the torque ratio of the torque converter 6 When it is determined that the driving force is exceeded, the maximum gear stage calculating means 134 at the time of lockup is when the turbine impeller 6t of the torque converter 6 and the pump impeller 6p are directly connected by the lockup clutch L / C. Then, the maximum gear (high-speed gear) when the minimum value of the gear ratio of the automatic transmission 8 capable of obtaining the necessary driving force is calculated. Here, even when the lockup clutch L / C is engaged, the maximum gear position of the automatic transmission 8 is calculated within a range in which the sum of the required driving force and the marginal driving force does not exceed the maximum driving force.

  The second fuel consumption amount calculating means 136 calculates the fuel consumption amount FB of the engine 9 when the automatic transmission 8 is set to the highest gear stage calculated by the maximum gear stage calculating means 134 at the time of lockup. The fuel consumption amount FB is a consumption amount necessary for generating the necessary driving force when the automatic transmission 8 is set to the highest gear (high speed gear), and the engine 9 for generating the necessary driving force. The fuel consumption amount FB is calculated on the basis of the fuel consumption map of the engine 9 using the accelerator opening degree Acc and the engine rotation speed NE of the engine 9 as parameters.

  The lockup clutch operating state selection means 138 is based on the comparison result between the fuel consumption FA calculated by the first fuel consumption calculation means and the fuel consumption FB calculated by the second fuel consumption calculation means 136. It is selected whether the torque converter 6 is in a state in which the capacity coefficient C is controlled by a capacity coefficient control means 140 described later or in a directly connected state by the lockup clutch L / C.

  When the lockup clutch operation state selection means 138 determines that the fuel consumption amount FA is less than the fuel consumption amount FB, the capacity coefficient control means 140 is implemented. The capacity coefficient control means 140 first determines whether or not the variable capacity control of the torque converter 6 is possible based on the storage state SOC of the power storage device 50 that supplies power to the electric motor 10 that drives the stator impeller 6s. To do. Then, the capacity coefficient control means 140 generates torque so that a required driving force can be obtained according to the gear ratio of the automatic transmission 8 (the gear ratio of the highest gear stage) calculated by the variable capacity maximum gear stage calculation means 130. The capacity coefficient C of the converter 6 is changed. Specifically, the capacity coefficient control control unit 140 determines that the torque is increased when the sum of the required driving force and a preset margin driving force exceeds the maximum driving force obtained at the gear ratio determined by the shift diagram. The capacity coefficient C of the converter 6 is reduced as compared with the case where the sum of the necessary driving force and the marginal driving force does not exceed the maximum driving force obtained by the gear ratio determined by the shift diagram.

FIG. 9 shows one mode when the capacity coefficient C is lowered by the capacity coefficient control means 140. If the accelerator pedal is depressed at time t1 during steady running, the accelerator opening Acc increases. At this time, the capacity coefficient control means 140 reduces the capacity coefficient C by driving the stator impeller 6s to rotate in the forward rotation direction. As a result, the load on the engine 9 is reduced, and the engine speed NE is quickly raised to the target speed as shown by the solid line. Along with this, the turbine rotational speed _NT is also quickly raised in the same manner. The broken lines show the engine speed NE and the turbine speed _NT when the capacity coefficient of the torque converter 6 is constant. The capacity coefficient C is controlled by the capacity coefficient control means 140 by, for example, feedback control based on the speed ratio e, feedforward control that is controlled so as to follow a preset capacity coefficient C, or timer control. The

  Here, since the torque ratio t is increased as the capacity coefficient C is decreased, the maximum driving force output from the torque converter 6 is increased as compared with the case where the capacity coefficient C is not decreased. That is, by generating the auxiliary driving force accompanying the increase in the torque ratio of the torque converter 6, the operation can be performed even in the operation region of the engine 9 that is not normally operated.

  Returning to FIG. 8, the lock-up control unit 142 determines that the lock-up clutch operation state selection unit 138 determines that the fuel consumption amount FB is smaller than the fuel consumption amount FA, or the vehicle state is locked in advance. When it is determined that it is in the up region, the lockup clutch L / C is controlled. When the lockup clutch L / C is completely engaged, the difference in rotational speed between the pump impeller 6p and the turbine impeller 6t becomes zero and the torque ratio t of the torque converter 6 becomes 1.

  FIG. 10 is a flowchart for explaining a main part of the control operation of the electronic control unit 78, that is, a control operation for driving the engine 9 in an area where the fuel consumption characteristic is excellent, and is extremely short, for example, about several msec to several tens msec. It is executed repeatedly at cycle time.

  First, in step SA1 (hereinafter, step is omitted) corresponding to the engine drive state determination means 120, it is determined whether or not the engine 9 is driven. If SA1 is negative, this routine is terminated. If SA1 is affirmed, it is determined in SA2 corresponding to the fuel efficiency-oriented travel determination means 122 whether or not the driver is directed to fuel efficiency-oriented travel. If SA2 is negative, normal shift traveling control based on the shift diagram is performed in SA13 corresponding to the shift control means 118.

  When SA2 is affirmed, the required driving force required for driving the vehicle is calculated in SA3 corresponding to the required driving force calculating means 124. Then, in SA4 corresponding to the capacity coefficient control means 140, it is determined whether or not the variable capacity control of the torque converter 6 is possible. When SA4 is affirmed, in SA5 corresponding to the driving force determining means 126 and the variable capacity maximum gear stage calculating means 130, the sum of the necessary driving force and the marginal driving force indicates the maximum driving force at the current gear ratio. And the sum of the necessary driving force and the marginal driving force is determined to be greater than the torque ratio of the torque converter 6. Among the gear stages of the automatic transmission 8 that do not exceed the maximum driving force after assistance assisted by the increase in t, the highest gear stage is calculated. The maximum gear stage is a gear stage for obtaining the required driving force, and is an optimum gear stage that can secure a preset margin driving force by reducing the capacity coefficient. Further, in SA6 corresponding to the maximum gear stage calculation means 134 at the time of lock-up, the highest gear stage is calculated among the gear stages of the automatic transmission 8 that can secure a marginal driving force when the lock-up clutch L / C is engaged. Is done. This maximum gear stage is a gear stage for obtaining the required driving force, and is an optimum that can secure a preset margin driving force when the lockup clutch L / C is engaged (torque ratio t = 1). It becomes a gear stage. Then, in SA7 corresponding to the first fuel consumption calculating means 132, when the automatic transmission 8 is set to the highest gear stage calculated by the variable capacity maximum gear stage calculating means 130, the torque by the capacity coefficient control means 140 is set. A fuel consumption amount FA of the engine 9 at the time of variable displacement control of the converter 6 is calculated. Similarly, in SA7 corresponding to the second fuel consumption calculation means 136, the fuel consumption FB of the engine 9 when the automatic transmission 8 is set to the highest gear stage calculated by the maximum gear stage calculation means 134 at the time of lockup. Is calculated.

  Then, in SA8 corresponding to the lockup clutch operating state selection means 138, the fuel consumption FA calculated by the first fuel consumption calculation means 132 and the fuel consumption FB calculated by the second fuel consumption calculation means 136 and On the basis of the comparison result, it is selected whether the torque converter 6 is in a state in which the capacity coefficient C is controlled by the capacity coefficient control means 140 or in a directly connected state by the lockup clutch L / C. Here, when it is determined that the fuel consumption amount FB is smaller than the fuel consumption amount FA and is in a lockup possible region, in SA9 corresponding to the lockup control means 142, the lockup in a state in which a marginal driving force is secured. Control is implemented. On the other hand, when it is determined that the fuel consumption amount FA is smaller than the fuel consumption amount FB, the variable capacity control of the torque converter 6 is performed in SA10 corresponding to the capacity coefficient control means 140.

  If SA4 is negative, it is determined in SA11 corresponding to the lockup control means 142 whether the vehicle state is within a preset lockup region. If SA11 is negative, normal shift traveling control based on the shift diagram is performed in SA13 corresponding to the shift control means 118. On the other hand, when SA11 is affirmed, lockup traveling is performed in SA12 corresponding to the lockup control means 142.

  FIG. 11 and FIG. 12 are area maps showing the use area of the engine 9. Here, the horizontal axis indicates the rotational speed NE of the engine 9, and the vertical axis indicates the engine torque TE. Moreover, the broken line in the area map indicates the equal fuel consumption consumption curve, and as shown in FIGS. 11 and 12, the closer to the ellipse indicated by the broken line in the relatively high torque area, the better the fuel consumption. Further, the solid line, the alternate long and short dash line, and the alternate long and two short dashes line indicate an equal output curve (equal power curve). As shown in FIGS. 11 and 12, when the engine 9 is driven in this high torque region, the fuel consumption characteristics are improved. Therefore, in the present embodiment, by utilizing the fact that the operating point of the engine 9 can be changed by controlling the capacity coefficient C by the capacity coefficient control means 140, high torque and low rotation (low speed) with the same power in steady running. When the engine 9 is operated in the (fuel consumption) region and the accelerator pedal is depressed, the capacity coefficient is changed to ensure that the vehicle can travel at high torque.

  For example, until now, due to the necessity of securing a sufficient driving force, it has been necessary to set the gear ratio of the automatic transmission 8 to the low gear side and to increase the engine rotation speed NE. That is, if the predetermined rotational speed is not maintained, the driving force is not generated when the accelerator pedal is depressed, and thus the automatic transmission 8 is in a low gear. This state corresponds to FIG. 12, and the steady running region is set to the low torque high rotation region. On the other hand, by changing the capacity coefficient C by the capacity coefficient control means 140, the automatic transmission 8 can be made high gear. That is, even in an operation region in which the marginal driving force cannot normally be secured, the marginal driving force can be secured by reducing the capacity coefficient C. Thus, as shown in FIG. 11, the steady running region of the engine 9 can be set to the high torque low rotation region, and the fuel consumption characteristics are improved.

  Thus, the capacity coefficient control means 140 can be controlled to operate in an area where the fuel consumption characteristics of the engine 9 are excellent by appropriately changing the capacity coefficient of the torque converter 6. Specifically, the engine is operated in a high torque and low rotation region by setting the gear of the automatic transmission 8 to the gear calculated by the variable capacity maximum gear calculating means 130. As a result, the engine 9 is driven in a region having excellent fuel consumption characteristics. Here, when the accelerator pedal is depressed in this state, the capacity coefficient control means 140 further reduces the capacity coefficient C of the torque converter 6 to further generate a marginal driving force, thereby enabling quick acceleration.

  Further, the variable capacity control of the torque converter 6 is also changed in the control mode depending on whether the torque converter 6 serving as a base has a high capacity coefficient or a low capacity coefficient. The torque converter 6 as a base is set according to the shape of the torque converter such as the pump impeller 6p, the turbine impeller 6t, the stator impeller 6s, etc. of the torque converter 6. For example, when the capacity coefficient of the torque converter 6 serving as a base is high, when the engine 9 is driven in a low rotation region as shown in FIG. 11 during steady running, the electric motor 10 is idled as shown in FIG. It becomes a state. When the accelerator pedal is depressed in this state, the capacity coefficient C of the torque converter 6 is reduced by driving the electric motor 10 in the forward rotation direction. On the other hand, when the capacity coefficient C of the torque converter serving as a base is low, when the engine 9 is driven in a low rotation region as shown in FIG. 11 during steady running, the electric motor 10 is driven in reverse rotation as shown in FIG. Braking). As a result, the capacity coefficient C of the torque converter 6 is higher than the torque converter 6 serving as a base. When the accelerator pedal is depressed in this state, the capacity coefficient C of the torque converter 6 is lowered by causing the electric motor 10 to idle.

  As described above, according to the present embodiment, the pump impeller 6p, the turbine impeller 6t, and the stator impeller 6s rotatably disposed between the turbine impeller 6t and the pump impeller 6p. Since the electric motor 10 for driving the torque converter 6 and the stator impeller 6s is provided, the stator impeller 6s is rotated by using the electric motor 10 in the positive rotation direction that is the rotation direction of the pump impeller 6p and the pump impeller 6p. By rotating in the negative rotation direction opposite to the rotation direction, the change range of the torque ratio t and the capacity coefficient C becomes wider than before, so that the fuel consumption performance and power performance of the vehicle can be greatly improved. it can.

  Further, according to the present embodiment, the engine 8 is optimally provided with the capacity coefficient control means 140 that changes the capacity coefficient C of the torque converter 6 in accordance with the gear ratio of the automatic transmission 8 so that the required driving force can be obtained. Can be operated in various operating areas. That is, the operating region of the engine 9 can be changed by changing the capacity coefficient C of the torque converter 6 with respect to the required driving force. As a result, for example, if the vehicle is directed to fuel efficiency-oriented travel, the operating region of the engine 9 can be operated in a region with excellent fuel consumption characteristics.

  Further, according to the present embodiment, the capacity coefficient control unit 140 is configured such that the sum of the required driving force and the preset margin driving force exceeds the maximum driving force obtained at the speed ratio determined by the shift diagram. The capacity coefficient C of the torque converter 6 is lower than when the sum of the required driving force and the preset margin driving force does not exceed the maximum driving force obtained at the gear ratio determined by the shift diagram. It is something to be made. In this way, since the torque ratio t increases, a driving force exceeding the maximum driving force can be obtained even in the operating region of the engine 9 where it is difficult to obtain a driving force exceeding the maximum driving force in the prior art. Can do. Thereby, the area width of the operation region of the engine 9 can be widened, and the engine 9 can be operated in the optimum operation region.

  Further, according to the present embodiment, the capacity coefficient control means 140 adjusts the capacity coefficient C of the torque converter 6 so that the driving force of the vehicle becomes the required driving force, so that the engine 9 has excellent fuel consumption characteristics. The required driving force can be obtained even in the operating state in the operating region.

  Further, according to the present embodiment, based on the comparison result between the fuel consumption amount FA calculated by the first fuel consumption amount calculation means 132 and the fuel consumption amount FB calculated by the second fuel consumption amount calculation means 136, Since the torque converter 6 has the lockup clutch operation state selection means 138 for selecting whether the capacity coefficient C is controlled by the capacity coefficient control means 140 or the direct connection state by the lockup clutch L / C. By switching to the control with the smaller consumption amount, the fuel consumption characteristic can be improved.

  In addition, according to the present embodiment, the shift control means 118 determines that the sum of the required driving force and the marginal driving force exceeds the maximum driving force at the current gear ratio by the driving force determining means 126 and the torque converter 6 When it is determined that the maximum driving force after assistance assisted by the increase in the torque ratio is exceeded, the downshift that increases the speed ratio from the current speed ratio is performed. Unobtainable driving force can be obtained.

  In addition, according to the present embodiment, the vehicle includes fuel efficiency-oriented travel determination means 122 that determines whether or not the vehicle is directed to fuel efficiency-oriented travel, and the capacity coefficient control means 140 uses the fuel efficiency-oriented travel determination means 140 to determine fuel efficiency. Since the capacity coefficient C of the torque converter 6 is changed so that the required driving force can be obtained when it is determined that the vehicle is traveling, the capacity coefficient C of the torque converter 6 is set according to the directivity state of the fuel economy-oriented traveling. It can be changed as appropriate. In other words, if traveling with emphasis on power performance, the engine 9 can be operated in an operation region where power performance is important.

  Further, according to the present embodiment, the shift control means 118 is located on the higher vehicle speed side than the shift diagram when the fuel consumption direction travel determining means 122 determines that the shift direction is not fuel efficiency oriented. The gear ratio of the automatic transmission 8 is switched stepwise based on the vehicle speed V and the accelerator opening Acc that manipulates the output of the engine 9 using a shift diagram to perform driving that emphasizes power performance can do.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, the stepped automatic transmission 8 is provided at the rear stage of the vehicle drive device 7, but the automatic transmission 8 is limited to the stepped transmission. Alternatively, for example, a continuously variable transmission such as a belt type continuously variable transmission may be used. That is, the structure of the transmission can be freely changed in the present invention within a consistent range.

In the illustrated embodiment, the required driving force is calculated based on the accelerator opening Acc and the vehicle speed V, the may be calculated based on the throttle valve opening theta _TH instead of the accelerator opening Acc.

  In the above-described embodiment, the clutch Cs that selectively connects the electric motor 10 and the stator impeller 6s and the brake Bs that selectively connects the case 11 and the stator impeller 6s are provided. Furthermore, the structure etc. which provided the clutch which selectively connects the electric motor 10 and the input shaft 22 may be sufficient. That is, by connecting the electric motor 10 and the input shaft 22, the electric motor 10 can also be used as a hybrid electric motor.

  In the above-described embodiment, the electric motor 10 and the stator impeller 6s are directly connected via the clutch Cs. For example, a planetary gear device is interposed between the planetary gear device and the planetary gear device. A configuration that enables torque conversion by a gear device may be used.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

1 is a skeleton diagram of a vehicle drive device to which a torque converter (variable capacity type torque converter) according to an embodiment of the present invention is applied. It is a figure which shows the relationship between an electric motor, a drive current, and a generated current. It is a table | surface explaining the operating state of each engagement element at the time of establishing each gear stage in an automatic transmission. FIG. 2 is a block diagram illustrating a control system provided in the vehicle for controlling the engine, the automatic transmission, the torque converter, or the like of FIG. 1. It is a figure which shows the shape of the blade | wing along the flow line of the hydraulic oil in the torque converter in each impeller, respectively. It is a figure which shows the torque ratio (torque amplification factor) of a turbine torque and a pump torque with respect to the rotational speed ratio of the turbine rotational speed of a turbine impeller, and the pump rotational speed of a pump impeller, ie, speed ratio. It is a figure which shows the relationship of the capacity | capacitance coefficient with respect to speed ratio. It is a functional block diagram explaining the principal part of the control action by an electronic control unit. This shows one mode when the capacity coefficient is lowered by the capacity coefficient control means. It is a flowchart explaining the principal part of the control action of an electronic controller, ie, the control action for driving an engine in the field where fuel consumption characteristics were excellent. It is an area | region map which shows the use area | region of an engine at the time of implementing variable capacity control of a torque converter. It is an area | region map which shows the use area | region of an engine in case the capacity | capacitance coefficient of a torque converter is constant. It is a figure which shows a control aspect when the capacity | capacitance coefficient of the torque converter used as a base is high. It is a figure which shows a control aspect when the capacity | capacitance coefficient of the torque converter used as a base is low.

Explanation of symbols

  6: Torque converter 6p: Pump impeller 6t: Turbine impeller 6s: Stator impeller 7: Vehicle drive device 8: Automatic transmission 9: Engine (drive source) 10: Electric motor (electric motor) 13: Drive wheel 118: Shift control means 122: Fuel consumption-oriented travel determination means 126: Driving force determination means 132: First fuel consumption amount calculation means 136: Second fuel consumption amount calculation means 138: Lockup clutch operating state selection means 140: Capacity coefficient control means Acc : Accelerator opening C: Capacity coefficient V: Vehicle speed

Claims (7)

A torque converter having a pump impeller, a turbine impeller, and a stator impeller rotatably disposed between the turbine impeller and the pump impeller, and an automatic change in gear ratio A control device for a vehicle drive device that includes a transmission and transmits power output from a drive source to drive wheels,
An electric motor capable of changing the capacity coefficient of the torque converter by driving or braking the stator impeller;
And a capacity coefficient control means for changing a capacity coefficient of the torque converter in accordance with a gear ratio of the automatic transmission so as to obtain a required driving force. The drive source is an internal combustion engine;
Shift control means for stepwise switching the gear ratio of the automatic transmission based on a vehicle speed and an accelerator opening for manipulating the output of the internal combustion engine from a preset shift diagram;
The capacity coefficient control means determines the capacity of the torque converter when the sum of the necessary driving force and a preset margin driving force exceeds a maximum driving force obtained at a gear ratio determined by the shift diagram. The coefficient is reduced as compared with a case where the sum of the necessary driving force and a preset margin driving force does not exceed the maximum driving force obtained at a gear ratio determined by the shift diagram. The control device for a vehicle drive device according to claim 1.   2. The control device for a vehicle drive device according to claim 1, wherein the capacity coefficient control means adjusts the capacity coefficient of the torque converter so that the drive force of the vehicle becomes a necessary drive force. Although the sum of the required driving force and the marginal driving force exceeds the maximum driving force, the maximum driving force after assistance assisted by an increase in the torque ratio of the torque converter, that is, the maximum driving force before assistance and the A first fuel consumption for calculating a fuel consumption amount when the capacity coefficient is controlled by the capacity coefficient control means when the speed ratio is set so as not to exceed the sum of the auxiliary driving force due to the torque ratio increase of the torque converter. A quantity calculating means;
Calculates fuel consumption when the minimum gear ratio among the gear ratios that can obtain the required driving force when the turbine wheel of the torque converter and the pump wheel are directly connected by a lock-up clutch. Second fuel consumption calculating means for
Based on the comparison result between the fuel consumption calculated by the first fuel consumption calculation means and the fuel consumption calculated by the second fuel consumption calculation means, the torque converter is controlled by the capacity coefficient control means. 4. The vehicle drive device according to claim 2, further comprising: a lockup clutch operation state selection unit that selects whether a capacity coefficient is controlled or a direct connection state by the lockup clutch. Control device. The sum of the necessary driving force and the marginal driving force exceeds the maximum driving force at the current gear ratio, and the maximum driving force after assistance assisted by an increase in the torque ratio of the torque converter, that is, before assistance. A driving force determining means for determining whether or not a sum of a maximum driving force and an auxiliary driving force due to an increase in the torque ratio of the torque converter is not exceeded;
The shift control means is assisted by the driving force determination means by the sum of the required driving force and the marginal driving force exceeding the maximum driving force at the current gear ratio and an increase in the torque ratio of the torque converter. 5. The vehicle according to any one of claims 1 to 4, wherein when it is determined that the maximum driving force after assistance is exceeded, a downshift that increases the speed ratio from the current speed ratio is performed. Control device for driving device. The vehicle includes a fuel consumption-oriented traveling determination unit that determines whether or not the vehicle is oriented to fuel-efficient traveling;
The capacity coefficient control means is configured to change a capacity coefficient of the torque converter so that the required driving force is obtained when the fuel efficiency oriented travel determination means determines that the fuel efficiency oriented travel is being performed. A control device for a vehicle drive device according to any one of claims 1 to 5.   When the shift control means determines that the fuel consumption direction travel determination means does not indicate fuel efficiency, the shift control means uses a shift diagram in which the shift line is located on the higher vehicle speed side than that of the shift diagram, 7. The control device for a vehicle drive device according to claim 6, wherein the gear ratio of the automatic transmission is switched in a stepwise manner based on an accelerator opening for manipulating the output of the internal combustion engine.

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