JP2009250380A - Controller of torque converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller of a torque converter capable of increasing a torque ratio and changing a capacity coefficient at a low level, sufficiently increasing the power performance of a vehicle, and reducing shock at the time of lock-up clutch shifting. <P>SOLUTION: A capacity coefficient controlling means 123 can reduce the shock at the time of lock-up clutch L/U shifting since both a rotational speed difference ΔN and a driving force difference ΔT (torque difference ΔT) between a pump impeller 6p and a turbine 6t at the time of lock-up clutch L/U shifting are reduced as the capacity coefficient C of a torque converter 6 is increased compared to the case where the lock-up clutch L/U is not being shifted when the lock-up clutch L/U is being shifted. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a torque converter control device provided in a vehicle, and more particularly to a variable capacity torque converter control device capable of changing the capacity of a torque converter.

  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.

  In general, a lock-up clutch that directly connects the pump impeller of the torque converter and the turbine impeller according to the traveling condition of the vehicle is provided. In such a lock-up clutch, if the rotational speed difference and the driving force difference (torque difference) between the pump impeller and the turbine impeller are large, a switching shock is likely to occur when the lock-up clutch is switched. In contrast, by controlling the slip-up of the lock-up clutch from the start to the end of the switch-up of the lock-up clutch, shock can be reduced. Since there is a limit to the performance, it is necessary to finish the control within a predetermined time, and it is difficult to say that the shock is sufficiently reduced.

  The present invention has been made against the background of the above circumstances. 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. And it is providing the control apparatus of the torque converter which can reduce the shock at the time of lockup clutch switching.

  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. Accordingly, the stator impeller is rotated (driven) in the positive rotation direction, which is the rotation direction of the pump impeller, and is rotated (driven, braked) in the negative rotation direction opposite to the rotation direction of the pump impeller using the 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. In addition, since the inventors can suppress slippage of the pump impeller and the turbine impeller by increasing the capacity coefficient of the torque converter, the inventors can increase the capacity coefficient when switching the lockup clutch. Found to reduce switching shock.

  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. And a torque converter control device comprising a torque converter having a stator impeller disposed on the shaft and a lockup clutch capable of directly connecting the pump impeller and the turbine impeller. And (c) capacity coefficient control means for controlling the capacity coefficient of the torque converter by controlling the motor, and (d) the capacity coefficient control means includes the lockup When the clutch is being switched, the capacity coefficient of the torque converter is increased compared to when the clutch is not being switched.

  According to a second aspect of the present invention, in the torque converter control device according to the first aspect, when the lock-up clutch is switched from the non-operating state to the operating state, the capacity coefficient control means includes: The capacity coefficient is increased from the time of determining the switching of the lockup clutch.

  The gist of the invention according to claim 3 is that, in the torque converter control device according to claim 1, when the lockup clutch is switched from the operating state to the non-operating state, the capacity coefficient control means is The capacity coefficient is increased from the start of actual switching of the lockup clutch.

  According to a fourth aspect of the present invention, there is provided the torque converter control device according to the second or third aspect, wherein the capacity coefficient control means has a predetermined rotational speed difference between the pump impeller and the turbine impeller. The capacity coefficient is controlled to be equal to or less than the value.

  According to a fifth aspect of the present invention, in the torque converter control device according to the second or third aspect, the capacity coefficient control means is configured so that the rotational speed of the turbine impeller changes at a predetermined gradient. It is characterized by controlling the capacity coefficient.

  According to the torque converter control device of the first aspect of the present invention, the torque having the pump impeller, the turbine impeller, and the stator impeller rotatably disposed between the turbine impeller and the pump impeller. Since the converter and the electric motor that drives the stator impeller are provided, the stator impeller is rotated using the electric motor in the positive rotational direction that is the rotational direction of the pump impeller and the negative rotational direction that is opposite to the rotational direction of the pump impeller. Since the torque ratio and the capacity coefficient change range becomes wider than in the past, the fuel efficiency and power performance of the vehicle can be greatly improved.

  In addition, the capacity coefficient control means increases the capacity coefficient of the torque converter when the lockup clutch is being switched compared to when the lockup clutch is not being switched. The rotational speed difference and the driving force difference (torque difference) between the impeller and the turbine impeller are reduced, and the shock at the time of switching the lockup clutch can be reduced.

  According to the torque converter control device of a second aspect of the present invention, when the lockup clutch is switched from the non-operating state to the operating state, the capacity coefficient control means is configured to determine whether the lockup clutch is to be switched. In order to increase the capacity coefficient, the rotational speed difference and the torque difference between the pump impeller and the turbine impeller can be reduced in advance until the actual lockup clutch switching start (at the start of engagement). It is possible to effectively reduce the switching shock when the actual lockup clutch is switched (engaged).

  According to the torque converter control device of a third aspect of the present invention, when the lockup clutch is switched from the operating state to the non-operating state, the capacity coefficient control means starts the actual switching of the lockup clutch. Since the capacity coefficient is increased from time to time, a sudden increase in the rotational speed difference and torque difference between the pump impeller and the turbine impeller can be suppressed from the start of switching of the lockup clutch (at the start of opening). The switching shock after the start of switching can be effectively reduced.

  According to the torque converter control device of the invention according to claim 4, the capacity coefficient control means sets the capacity coefficient so that a rotational speed difference between the pump impeller and the turbine impeller is equal to or less than a predetermined value. In order to control, the increase of the rotational speed difference and torque difference of a pump impeller and a turbine impeller can be suppressed.

  According to the torque converter control device of the present invention, the capacity coefficient control means controls the capacity coefficient so that the rotational speed of the turbine impeller changes with a predetermined gradient. An increase in rotational speed difference and torque difference between the vehicle and the turbine impeller can be suppressed.

  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 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 / U is provided between the pump impeller 6p and the turbine impeller 6t, and the hydraulic control circuit 30 is engaged with the lockup clutch L / U, slipped, or The disengaged state is controlled, and the pump impeller 6p and the turbine impeller 6t are integrally rotated by being brought into the complete engagement state, that is, the crankshaft of the engine 9 and the input shaft 22 are directly connected to each other. It is supposed to be in a state.

  Further, the vehicle drive device 7 is connected to the stator impeller 6s of the torque converter 6 so as to be able to transmit power, and is capable of rotational control, and between the electric motor 10 and the stator impeller 6s. And a brake Bs capable of intermittently connecting between the stator impeller 6s and a transmission case (hereinafter referred to as a case) 11 which 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 of accession is an operation amount of the accelerator operating member such as an accelerator pedal 98 from an accelerator operation amount sensor 96 Indicating signal indicating Le opening A _CC, 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, a lever position (operating position) P _SH of the shift lever 106 from the lever position sensor 104 Signals are supplied.

  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 an electronic throttle valve 108, a fuel injection device 110, an ignition device 112, etc., which are part of the engine output control device.

  The shift control of the automatic transmission 8 is performed by the hydraulic control circuit 30. For example, the gear stage to be shifted of the automatic transmission 8 based on the accelerator opening Acc and the vehicle speed V from a previously stored shift diagram (shift map). And the engagement / release states of the clutches C1 to C4 and the brakes B1 and B2 are switched according to the operation table shown in FIG. 3 so as to establish the determined gear.

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 and the electric motor 10. Specifically, the rotation control of the stator impeller 6s is performed by a drive torque T _D proportional to the magnitude of the drive current I _D supplied from the inverter to the electric motor 10 in accordance with a command from the electronic control device 78, or for example, its electric drive. braking torque T _B is executed by being appropriately adjusted in proportion to the magnitude of the generated current I _G to be output from the 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, stator 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 ) Equation (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 by the clutch Cs and the brake Bs is released is made zero, the increase in the torque is not performed as indicated by a chain line of the stator free 6, torque ratio t = 1 Torque is transmitted at. 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. Furthermore, 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 driving or braking (regeneration). It is. 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 operation by the electronic control unit 78. The shift control means 120 functions as a control means for shifting the automatic transmission 8. The shift control means 120 switches the gear ratio of the automatic transmission 8 in a stepwise manner based on, for example, a preset shift diagram (not shown) based on the vehicle speed V and the accelerator opening Acc for operating the output of the engine 9.

  The lock-up control means 122 controls the engagement hydraulic pressure of the lock-up clutch L / U serving as a drive source for engaging the lock-up clutch L / U in the torque converter 6, thereby engaging the lock-up clutch L / U. The combined state is preferably controlled. Specifically, for example, when the state of the vehicle is within a lockup operation region in a preset lockup region diagram (not shown), the lockup control means 122 increases the engagement hydraulic pressure to increase the lockup clutch L. / U is completely engaged, that is, the pump impeller 6p and the turbine impeller 6t are directly connected. On the other hand, when the vehicle state is out of the lock-up operation region, the lock-up control means 122 releases the lock-up clutch L / U by reducing the engagement hydraulic pressure. Further, the lockup control means 122 absorbs torque fluctuations of the engine 9 by giving a slight slip to the lockup clutch L / U even in the lockup operation region.

  The capacity coefficient control means 123 controls the rotational speed by rotating, reversing, or braking (regenerating) the stator impeller 6s, or changing the engagement pressure of the brake Bs to thereby change the capacity coefficient of the torque converter 6. C is suitably controlled according to the state of the vehicle. Note that the capacity coefficient control of the torque converter 6 by the capacity coefficient control means 123 is substantially the same as the rotational speed control of the stator impeller 6 s by the electric motor 10.

  Specifically, the capacity coefficient control means 123 engages the clutch Cs, for example, when the vehicle starts or accelerates, and causes the electric impeller 10 to rotate the stator impeller 6s in the same rotational direction as the pump impeller 6p. Take control. As a result, the torque ratio t of the torque converter 6 is increased and the capacity coefficient C is decreased as described above. The increase of the torque ratio t increases the starting torque or the acceleration torque, and the reduction of the capacity coefficient C makes it possible to smoothly increase the engine speed. Such control is effective during acceleration (power performance) oriented traveling such as a high accelerator opening, and is particularly effective when executed in a turbocharger engine or the like that requires a smoother increase in engine rotation. .

  Further, the capacity coefficient control means 123 performs control such that the clutch Cs is engaged and the electric motor 10 is rotated by torque acting on the stator impeller 6s, for example, when the vehicle starts or accelerates. Thereby, when the torque converter 6 amplifies the torque when the vehicle starts or accelerates, the rotation direction of the pump impeller 6p is caused by the torque that the stator impeller 6s receives from the fluid flow, that is, the reaction torque, as described above. The amount of regeneration of the electric motor 10 is controlled as it is rotated in the negative rotation direction opposite to. As a result, the torque ratio t of the torque converter 6 is reduced and the capacity coefficient C is increased. Such control is effective during low fuel consumption oriented traveling such as low accelerator opening. Further, fuel efficiency can be improved by regeneration of the electric motor 10.

  Further, the capacity coefficient control means 123 can change the operating area of the engine 9 to an area having excellent fuel consumption characteristics by controlling the capacity coefficient C. Specifically, since the load applied to the engine 9 can be changed by changing the capacity coefficient C, the operating range of the engine 9 is set to an area with excellent fuel consumption characteristics (for example, for the same required driving force). It is controlled so as to be operated in a low rotation high torque region).

  Further, the capacity coefficient control means 123 controls the capacity coefficient C by controlling the engagement pressure of the brake Bs. For example, the capacity coefficient control unit 126 stops the rotation of the stator impeller 6s by increasing the engagement pressure of the brake Bs to a level at which the brake Bs is completely engaged in the torque converter range. Thus, the capacity coefficient C of the torque converter 6 is controlled so as to become the baseline BC shown in FIG. Further, when the torque converter 6 is in the coupling range, the brake Bs is released to cause the stator impeller 6s to idle. Further, the capacity coefficient control means 123 controls the engagement pressure of the brake Bs and slips the brake Bs to control the capacity coefficient C when, for example, it is necessary to reduce the driving torque during traveling. Increase.

  Further, the capacity coefficient control means 123 is when the lock-up clutch L / U provided in the torque converter 6 is switching, that is, during switching control from the operating state to the non-operating state or from the non-operating state to the operating state. The capacity coefficient C of the torque converter 6 is increased as compared to when not switching. In the present embodiment, the term “during switching” includes the period from when the lockup clutch L / U is switched to when the switching is completed. Hereinafter, this control will be described in detail.

  The lockup control execution request determination unit 124 determines whether or not the state of the lockup clutch L / U is switched, specifically, the lockup clutch L / U is in an inoperative state (released) from an operating state (engaged state). State) or inactive state (released state) to operating state (engaged state). The lock-up control execution request determination means 124 moves the vehicle state from the lock-up operation region to the lock-up non-operation region based on, for example, a lock-up region diagram including a preset accelerator opening Acc and vehicle speed V. Whether or not it has moved from the lock-up non-operating area to the lock-up operating area.

The rotational speed difference determining means 126 detects the pump rotational speed N _P of the torque converter 6 (that is, the engine rotational speed NE) and the turbine rotational speed _NT, and the rotational speed difference ΔN (= N _P −N _T = NE−). It is determined whether or not (N _T ) exceeds a predetermined rotational speed difference ΔN1 (predetermined value ΔN1). Note that the predetermined rotational speed difference ΔN1 is experimentally obtained in advance, for example, set to a relatively low value or a time from the start of actual switching of the lockup clutch L / U. Alternatively, it may be changed according to the time from the determination of switching the lockup clutch.

Instead of the rotational speed difference ΔN, for example, the pump torque T _P (that is, the engine torque TE) and the turbine torque T _T are detected, and the torque difference ΔT (= T _P −T _T ) becomes a predetermined torque difference ΔT1. Even if it is determined whether or not the difference is exceeded, the same effect as the rotational speed difference determining means 126 can be provided.

  The capacity control availability determination means 128 determines whether or not the capacity coefficient control means 123 can be implemented. Specifically, for example, whether or not the electric motor 10 is operable, whether or not the clutch Cs that connects and disconnects the electric motor 10 and the stator impeller 6 s is operable, or the power storage device 50 that supplies electric power to the electric motor 10 It is determined whether or not the capacity coefficient control means 123 can be implemented based on whether or not the charge capacity SOC of the battery is below a controllable lower limit value. If this determination is affirmed, the capacity coefficient control means 123 can be implemented.

The capacity coefficient control means 123 is implemented based on the determination results of the above means. First, it is determined by the lockup control execution request determination means 124 that the state of the lockup clutch L / U is switched. Specifically, it is determined that the lockup control L / U is switched from the operating state to the non-operating state. that the capacity coefficient control unit 123, with respect to the rotational speed difference determining means 126, together to calculate the rotational speed difference ΔN of the pump rotational speed N _P and the turbine rotational speed N _T, the rotation the rotational speed difference ΔN is given It is determined whether or not the speed difference ΔN1 is exceeded. Then, according to the determination result of the rotational speed difference determination means 126, the capacity coefficient control means 123 engages the clutch Cs and performs an increase control of the capacity coefficient C of the torque converter 6.

  FIG. 9 is a time chart for explaining a control method for increasing control of the capacity coefficient C by the capacity coefficient control means 123. FIG. 10 shows the state of the torque converter 6 when the capacity coefficient control is not performed as a comparison target. Here, FIGS. 9 and 10 show that, for example, the lockup clutch L / U operates during deceleration traveling with the accelerator pedal 98 slightly depressed while the lockup clutch L / U is in an activated state (engaged state). A state when the state (engaged state) is switched to the non-operating state (released state) (release control) is shown as an example.

If it is determined by the lockup control execution request determination means 124 that the lockup clutch L / U is to be released at time t1 in FIG. 9, the lockup clutch L / U is unlocked by the lockup control means 122 at time t2. Open control (switching control) is started. At the same time, the capacity coefficient control means 123 starts increasing control of the capacity coefficient C of the torque converter 6. That is, in the case of switching from the operating state of the lockup clutch L / U to the non-operating state, the increase control of the capacity coefficient C is started from the start of actual switching of the lockup clutch L / U. The capacity when the coefficient C increases, the slip of the pump impeller 6p and turbine wheel 6t is suppressed, the rotation speed difference ΔN between the pump rotational speed N _P and the turbine rotational speed N _T is reduced, the pump torque A torque difference ΔT between T _P (= engine torque TE) and turbine torque T _T becomes small. The control method of the capacity coefficient C, for example, constantly calculates a rotation speed difference .DELTA.N the pump rotational speed N _P and the turbine rotational speed N _T, to implement the feedback control based on the rotational speed difference .DELTA.N. For example, in FIG. 9, it is assumed that the predetermined rotational speed difference ΔN1 is set so as to increase at a predetermined gradient with reference to the time t2 when the actual switching (release) of the lockup clutch L / U is started. The capacity coefficient control means 123 performs feedback control so that the rotational speed difference ΔN is equal to or less than the set predetermined rotational speed difference ΔN1. Note that the predetermined rotation speed difference ΔN1 is set to a low value so that the rotation speed difference ΔN does not rapidly spread, and thus the capacity coefficient C is increased. Note that the pump torque T _P (that is, the engine torque TE) and the turbine torque T _T are detected instead of the feedback control of the rotational speed difference ΔN, and the feedback control based on the torque difference ΔT is performed similarly. An effect can be obtained.

Further, the capacity coefficient control means 123 can also perform feedback control of the capacity coefficient C so that the turbine rotational speed _NT of the turbine impeller 6t changes at a predetermined gradient θ1 obtained experimentally in advance. Similarly, the predetermined gradient θ1 at this time is set to a low value so that the turbine rotational speed NT does not change suddenly, so that the capacity coefficient C is increased. This, at time t2 to t3 point, the capacity coefficient C is increased, the spread of the rotation speed difference ΔN of the pump rotational speed N _P and the turbine rotational speed N _T is reduced.

When the release of the lockup clutch L / U by the lockup control means 123 is completed at time t3, the capacity coefficient control means 123 returns the capacity coefficient C to the normal capacity coefficient C from time t3 to time t4. The return control of the capacity coefficient C to be performed is performed. Here, the normal capacity coefficient C is set to, for example, the capacity coefficient C when the capacity coefficient control is not performed, that is, the capacity coefficient C of the baseline BC in FIG. Again, as the rotational speed difference .DELTA.N the pump rotational speed N _P and the turbine rotational speed N _T is not spread rapidly, to implement the feedback control based on the rotational speed difference .DELTA.N. Alternatively, feedback control of the capacity coefficient C is performed so that the capacity coefficient C is returned with a predetermined gradient.

  In this way, by performing the increase control of the capacity coefficient C of the capacity coefficient control means 123, as shown in FIG. 9, the pump impeller 6p and the turbine are in operation while the lockup clutch L / U is being opened (switching). The rotational speed difference ΔN and the torque difference ΔT of the impeller 6t do not change abruptly, and the switching shock of the lockup clutch L / U is reduced. If the increase control of the capacity coefficient C by the capacity coefficient control means 123 is not performed, as shown in FIG. 10, the change gradients of the rotational speed difference ΔN and the torque difference ΔT between the pump impeller 6p and the turbine impeller 6t become large. The switching shock of the lockup clutch L / U becomes large.

  Next, increase control of the capacity coefficient C by the capacity coefficient control means 123 when the lockup clutch L / U is switched from the non-operating state (released state) to the operating state (engaged state) (engagement control) will be described. . FIG. 11 shows a state in which it is determined that the lockup clutch L / U is engaged (actuated) when the vehicle speed V increases, for example, in a state where the lockup clutch L / U is released (non-actuated state). It is a time chart which shows operation control (engagement control).

At time t1, when the lockup clutch L / U switching signal is output based on the lockup control execution request determination means 124, that is, when it is determined that the lockup clutch L / U is to be engaged, the capacity coefficient The control means 123 starts increasing control of the capacity coefficient C. That is, when the lockup clutch L / U is switched from the non-operating state to the operating state, the capacity coefficient control means 123 increases the capacity coefficient C from the time of switching determination of the lockup clutch L / U. Here, the capacity coefficient C of the torque converter 6 is increased, the slip of the pump wheel 6p and turbine wheel 6t is reduced, the rotational speed difference ΔN of the pump rotational speed N _P and the turbine rotational speed N _T is reduced Therefore, the capacity coefficient C is preferably controlled to increase. More specifically, for example, to detect the pump rotation speed N _P and the turbine rotational speed N _T, given until time t2 that these rotational speed difference ΔN is the engagement control of the lock-up clutch L / U is started The feedback control of the capacity coefficient C is performed so that the rotational speed difference ΔN2 is obtained. The predetermined rotational speed difference ΔN2 is set in advance and is set to a value close to zero. That is, at the time point t2 when the engagement control of the lockup clutch L / U is started, the rotational speed difference ΔN between the pump impeller 6p and the turbine impeller 6t is set to be almost eliminated. By doing so, the rotational speed difference ΔN and the torque difference ΔT between the pump impeller 6p and the turbine impeller 6t when starting the engagement control of the lockup clutch L / U at the time t2 are reduced, and the lockup clutch L Shock when / U is engaged is reduced.

  FIG. 12 is a flow chart for explaining the control operation of the electronic control device 78, that is, the control operation for reducing the switching shock when the switching control of the lock-up clutch L / U is performed, for example, several msec to several tens msec. It is repeatedly executed with an extremely short cycle time. In addition, this flowchart has shown the control action at the time of engagement control of the lockup clutch L / U as an example.

First, in step SA1 (hereinafter, step is omitted) corresponding to the lockup control execution request determination means 124, it is determined whether or not the lockup clutch L / U switching control is started. If SA1 is negative, this routine is terminated. When SA1 is positive, in SA2 corresponding to the rotation speed difference determining unit 126, the pump rotational speed _{N P} and the turbine rotational speed _{N T} is detected. Also, when the increase control of the capacity coefficient C is performed based on the pump torque T _P and the turbine torque T _T, the pump torque T _{P (that} is, the engine torque TE) and the turbine torque T _T is detected. Then, further in SA3 corresponding to the rotational speed difference judging means 126 calculates a rotation speed difference ΔN between the detected pump rotational speed N _P and the turbine rotational speed N _T, calculated rotation speed difference ΔN is set in advance It is determined whether or not it is greater than a predetermined rotational speed difference ΔN2. If SA3 is negative, lockup switching control is performed in SA6 corresponding to the lockup control means 122. If SA3 is affirmed, it is determined in SA4 corresponding to the capacity control availability determination means 128 whether or not the increase control of the capacity coefficient C is feasible. If SA4 is negative, normal lockup switching control is performed in SA6. When SA4 is affirmed, increase control of the capacity coefficient C is performed in SA5 corresponding to the capacity coefficient control means 123. Then, again in SA3, the rotational speed difference ΔN changed as the capacity coefficient C increases is calculated, and it is determined whether or not the newly calculated rotational speed difference ΔN is larger than a predetermined rotational speed difference ΔN2. . That is, in SA3, the increase control of the capacity coefficient C is repeatedly performed in SA5 until the rotational speed difference ΔN does not exceed the predetermined rotational speed difference ΔN2. When the rotational speed difference ΔN falls within the predetermined rotational speed difference range, lockup switching control is performed in SA6.

  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 that drives the torque converter 6 and the stator impeller 6s is provided, the stator impeller 6s is rotated in the positive rotation direction that is the rotation direction of the pump impeller 6p using the electric motor 10, 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 efficiency and power performance of the vehicle are greatly improved. Can do.

  Further, according to the present embodiment, the capacity coefficient control means 123 increases the capacity coefficient C of the torque converter 6 when the lockup clutch L / U is being switched compared to when the lockup clutch L / U is not being switched. Therefore, the rotational speed difference ΔN and the driving force difference ΔT (torque difference ΔT) between the pump impeller 6p and the turbine impeller 6t when the lockup clutch L / U is switched are reduced, and the lockup clutch L / U is switched. The shock at the time can be reduced.

  Further, according to this embodiment, when the lockup clutch L / U is switched from the non-operating state to the operating state, the capacity coefficient control means 123 sets the capacity coefficient C from the time of switching determination of the lockup clutch L / U. In order to increase the rotational speed difference ΔN and torque difference ΔT between the pump impeller 6p and the turbine impeller 6t before the actual switching of the lockup clutch L / U is started (at the start of engagement). Thus, the switching shock at the time of switching (engagement) of the actual lockup clutch L / U can be effectively reduced.

  Further, according to the present embodiment, when the lockup clutch L / U is switched from the operating state to the non-operating state, the capacity coefficient control means 123 has the capacity coefficient C from the start of the actual switching of the lockup clutch L / U. Therefore, a sudden increase in the rotational speed difference ΔN and the torque difference ΔT between the pump impeller 6p and the turbine impeller 6t can be suppressed from the start of switching of the lockup clutch L / U (at the start of opening). The switching shock after the start of switching of the up clutch L / U can be effectively reduced.

  Further, according to the present embodiment, the capacity coefficient control means 123 controls the capacity coefficient C so that the rotational speed difference ΔN between the pump impeller 6p and the turbine impeller 6t is equal to or less than a predetermined value. An increase in the rotational speed difference ΔN and the torque difference ΔT between 6p and the turbine impeller 6t can be suppressed.

Further, according to the present embodiment, the capacity coefficient control means 123 controls the capacity coefficient C so that the rotational speed _NT of the turbine impeller 6t changes with a predetermined gradient θ1, so that the pump impeller 6p and the turbine impeller An increase in the rotational speed difference ΔN and torque difference ΔT of the 6t vehicle can be suppressed.

  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, increased control of the capacity coefficient C has been carried out feedback control based on the rotational speed difference ΔN between the pump rotational speed N _P and the turbine rotational speed N _T, increased control of the capacity coefficient C is limited to the control Sarezu, for example, may be performed experimentally determined in advance was feedforward control based on the rotational speed N _S of the stator wheel 6s, or a timer control.

  In the above-described embodiment, the stepped automatic transmission 8 is provided at the rear stage of the vehicle drive device 7. However, 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 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.

  In the above-described embodiment, when the lockup clutch L / U is switched from the operating state to the non-operating state (release control), the capacity coefficient C is increased when the release control of the lockup clutch L / U is actually started. However, the present invention is not necessarily limited to the time when the actual release control of the lockup clutch L / U is started. Even if the increase control of the capacity coefficient C is performed in advance from the time when the release control execution of the lockup clutch is determined. I do not care. Similarly, even when the lockup clutch L / U is switched from the non-operating state to the operating state (engagement control), the increase control of the capacity coefficient C needs to be started immediately after the determination of the switching of the lockup clutch L / U. No, the increase control of the capacity coefficient C may be performed after a predetermined time has elapsed.

  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. It is a time chart explaining the control method of the increase control of a capacity coefficient by a capacity coefficient control means. It is a time chart which shows the rotational speed change and torque change of a pump impeller and a turbine impeller when not performing capacity coefficient control. It is another time chart explaining the control method of the increase control of a capacity coefficient by a capacity coefficient control means. It is a flowchart explaining the control operation | movement which reduces the switching shock when implementing the principal part of the control action of an electronic controller, ie, the switching control of a lockup clutch.

Explanation of symbols

  6: Torque converter 6p: Pump impeller 6t: Turbine impeller 6s: Stator impeller 10: Electric motor (electric motor) 123: Capacity coefficient control means C: Capacity coefficient L / U: Lock-up clutch ΔN: Rotational speed difference ΔN1, ΔN2: Predetermined rotational speed difference (predetermined value) θ1: Predetermined gradient

Claims (5)

A pump impeller, a turbine impeller, a stator impeller rotatably disposed between the turbine impeller and the pump impeller, and a lock-up clutch capable of directly connecting the pump impeller and the turbine impeller A torque converter control device comprising a torque converter having
An electric motor coupled to the stator impeller so as to be capable of transmitting power;
Capacity coefficient control means for controlling the capacity coefficient of the torque converter by controlling the electric motor,
The torque coefficient control means increases the capacity coefficient of the torque converter when the lockup clutch is being switched compared to when the lockup clutch is not being switched.   2. The torque converter according to claim 1, wherein, when the lockup clutch is switched from an inoperative state to an activated state, the capacity coefficient control means increases the capacity coefficient from the time of switching determination of the lockup clutch. 3. Control device.   2. The torque according to claim 1, wherein when the lockup clutch is switched from an operating state to a non-operating state, the capacity coefficient control means increases the capacity coefficient from the start of actual switching of the lockup clutch. Converter control device.   4. The torque converter control device according to claim 2, wherein the capacity coefficient control means controls the capacity coefficient so that a difference in rotational speed between the pump impeller and the turbine impeller is a predetermined value or less. .   4. The torque converter control device according to claim 2, wherein the capacity coefficient control means controls the capacity coefficient so that the rotational speed of the turbine impeller changes with a predetermined gradient.

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