Vehicle drive device control device

Abstract

To provide a vehicle drive system control device capable of achieving a smooth gear change through smoothly engaging a clutch without impairing drivability even when a lock-up clutch is not engaged.SOLUTION: A vehicle drive system control device comprises: a torque converter with a lock-up clutch connected to an engine; a transmission mechanism which outputs engine rotation by changing a rotation speed; a transmission clutch arranged between the torque converter and the transmission mechanism; and a clutch actuator which automatically perform a clutch operation. When a gear is changed with the lock-up clutch released, the clutch control section calculates engine demand torque Ter on the basis of a target turbine rotation speed Nt*. The engine is controlled on the basis of the engine demand torque Ter when the gear is changed with the lock-up clutch released.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a control device for a vehicle drive device. [Background technology]

[0002] Patent Document 1 discloses a power transmission device that includes a fluid coupling that transmits engine power to the transmission side, a lock-up clutch for mechanically connecting and disconnecting the fluid coupling, and a speed change clutch that is provided between the fluid coupling and the transmission and that is connected and disconnected in response to a gear change operation of the transmission, and that connects the lock-up clutch before the speed change clutch when a peculiar starting operation is performed by the driver. The power transmission device described in Patent Document 1 can prevent poor connection of the lock-up clutch. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-76667 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the power transmission device described in Patent Document 1, the control related to the engagement of the shift clutch cannot be performed until the lock-up clutch is engaged, which lengthens the time required for shifting. If the time required for shifting becomes too long, for example, during acceleration when starting from a standstill, acceleration may become sluggish, which may deteriorate drivability.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a control device for a vehicle drive device that can smoothly engage the shift clutch and perform smooth gear changes without compromising drivability, even when the lock-up clutch is not engaged. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the present invention provides a control device for a vehicle drive device including a torque converter with a lock-up clutch connected to an engine, a transmission mechanism that changes the rotation of the engine at a gear ratio corresponding to the gear stage and outputs the rotation, a transmission clutch that is provided between the torque converter and the transmission mechanism and can be switched to an engaged state in which power is transmitted or a disconnected state in which power is disconnected, and a clutch actuator that automatically operates the transmission clutch, the control device including a control unit that controls the drive of the clutch actuator, and when a transmission is performed to switch the gear stage with the lock-up clutch released, the control unit calculates an engine required torque, which is a required value of the torque output from the engine, based on a target turbine rotation speed that is a target rotation speed of a turbine shaft connected to the torque converter and the transmission clutch, and when the transmission is performed, the engine is controlled based on the engine required torque. Effect of the Invention

[0007] According to the present invention, a control device for a vehicle drive device can be provided that can smoothly engage the shift clutch to perform smooth gear changes without compromising drivability, even when the lock-up clutch is not engaged. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of a vehicle equipped with a control device for a vehicle drive device according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a conceptual diagram of a power transmission system of a vehicle equipped with a control device for a vehicle drive device according to one embodiment of the present invention. [Diagram 3] FIG. 3 is a block diagram showing a flow of calculation of engine required torque in the control device for a vehicle drive device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A control device for a vehicle drive device according to one embodiment of the present invention includes a torque converter with a lock-up clutch connected to an engine, a speed change mechanism that changes the speed of the engine at a speed ratio corresponding to a gear shift and outputs the changed speed, a speed change clutch that is provided between the torque converter and the speed change mechanism and can be switched between an engaged state for transmitting power and a disconnected state for disconnecting the power, and a clutch actuator that automatically operates the speed change clutch, and includes a control unit that controls the drive of the clutch actuator, and when a speed change is performed to switch the gear shift while the lock-up clutch is released, the control unit calculates an engine required torque that is a required value of the torque output from the engine based on a target turbine rotation speed that is a target rotation speed of a turbine shaft connected to the torque converter and the speed change clutch, and when a speed change is performed, the engine is controlled based on the engine required torque. As a result, the control device for a vehicle drive device according to one embodiment of the present invention can smoothly engage the speed change clutch without impairing drivability and perform a smooth speed change even when the lock-up clutch is not engaged. EXAMPLES

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle equipped with a control device for a vehicle drive device according to an embodiment of the present invention will now be described with reference to the drawings.

[0011] As shown in FIG. 1, a vehicle 1 includes an engine 2 as an internal combustion engine, an automatic transmission 3 as a vehicle drive device, drive wheels 4, a control device 10, and an engine controller 20.

[0012] The engine 2 is formed with a plurality of cylinders. In this embodiment, the engine 2 is configured to perform a series of four strokes, which are an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke, for each cylinder. The engine 2 is a power source for the vehicle 1.

[0013] The automatic transmission 3 is provided in a power transmission path between the engine 2 and drive wheels 4. The automatic transmission 3 has a torque converter 30, a speed change mechanism 31, a speed change clutch 32, and a clutch actuator 33.

[0014] The torque converter 30 is a so-called torque converter with a lock-up clutch, which has a lock-up clutch 35. The torque converter 30 is provided in a power transmission path between the engine 2 and the variable speed clutch 32, and transmits power via a fluid to output the power to a turbine shaft 36.

[0015] A variable speed clutch 32 is connected to the turbine shaft 36. The torque converter 30 amplifies the torque (driving force) input from the crankshaft 21 of the engine 2 by a rotation difference through a fluid, and outputs the amplified torque to the turbine shaft 36 and the variable speed clutch 32. The output of the torque converter 30 is then transmitted to the transmission mechanism 31 via the turbine shaft 36 and the variable speed clutch 32.

[0016] The inside of the torque converter 30 is divided into an apply chamber and a release chamber (not shown) by the lock-up clutch 35. Hydraulic oil is supplied to the apply chamber or the release chamber, and the operating state of the lock-up clutch 35 is switched depending on the hydraulic pressure (hydraulic oil pressure) of the supplied hydraulic oil.

[0017] The lock-up clutch 35 is provided within the torque converter 30, and its operating state can be switched between a connected state (hereinafter referred to as "direct connection") in which the crankshaft 21 and turbine shaft 36 of the engine 2 rotate integrally to transmit power, and a released state in which the direct connection between the crankshaft 21 and the turbine shaft 36 is released and the crankshaft 21 and the turbine shaft 36 transmit power via a fluid (hydraulic oil).

[0018] The lock-up clutch 35 is switched to the engaged state by supplying hydraulic pressure (hereinafter, this hydraulic pressure is referred to as "engagement hydraulic pressure") to the apply chamber and discharging hydraulic oil from the release chamber. Conversely, the lock-up clutch 35 is switched to the released state by supplying hydraulic pressure (hereinafter, this hydraulic pressure is referred to as "release hydraulic pressure") to the release chamber and discharging hydraulic oil from the apply chamber.

[0019] The transmission mechanism 31 is provided in a power transmission path between the transmission clutch 32 and the drive wheels 4, and has an input shaft 37 connected to the transmission clutch 32, and an output shaft 38 connected to the drive wheels 4 via a differential (not shown). The transmission mechanism 31 converts the driving force input from the transmission clutch 32 to the input shaft 37, changes the rotational speed, and outputs it from the output shaft 38.

[0020] The transmission mechanism 31 changes the rotation of the engine 2, which is output from the engine 2 and transmitted to an input shaft 37, at a gear ratio corresponding to one of a plurality of gears, which will be described later, selected, and outputs the changed rotation to an output shaft 38. The rotation and driving force output to the output shaft 38 are transmitted to the drive wheels 4 via a differential, not shown.

[0021] The transmission mechanism 31 is configured to be capable of forming a plurality of gear stages with different gear ratios by a plurality of gear pairs with different gear ratios. The gear stages in the transmission mechanism 31 are automatically switched by a shift actuator (not shown). In detail, the control device 10 judges whether a gear shift is necessary by referring to a gear shift map based on the vehicle speed and the depression amount of the accelerator pedal, and outputs a gear shift command to the shift actuator. Then, the shift actuator that receives the gear shift command operates to perform the gear shift.

[0022] The variable speed clutch 32 is provided in a power transmission path between the torque converter 30 and the transmission mechanism 31. The variable speed clutch 32 has a clutch wheel disc 32a connected to the turbine shaft 36 so as to rotate integrally therewith, and a clutch disc 32b connected to the input shaft 37 of the transmission mechanism 31 so as to rotate integrally therewith.

[0023] The variable speed clutch 32 is a dry single-plate clutch that can be switched between an engaged state in which the clutch disc 32b is pressed against the clutch wheel disc 32a to rotate together with the clutch wheel disc 32a to transmit power, and a disconnected state in which the clutch disc 32b is separated from the clutch wheel disc 32a to disconnect the power transmission between the clutch wheel disc 32a and the clutch disc 32b. In other words, the variable speed clutch 32 transmits power between the turbine shaft 36 and the input shaft 37 in the engaged state, and disconnects the power transmission between the turbine shaft 36 and the input shaft 37 in the disconnected state.

[0024] The operation of switching the speed-change clutch 32 between an engaged state and a disengaged state (hereinafter referred to as “clutch operation”) is performed automatically by a clutch actuator 33.

[0025] The clutch actuator 33 is electrically connected to the control device 10, and performs clutch operation of the speed change clutch 32 based on a command from the control device 10. Specifically, the clutch actuator 33 moves a release bearing (neither of which is shown) in the axial direction of the input shaft 37 using a release fork or the like, and causes the release bearing to elastically deform a diaphragm spring of the clutch wheel disc 32a, thereby disengaging the speed change clutch 32. The clutch actuator 33 also moves the release bearing from the disengaged position in the opposite direction to that used for disengaging the clutch, thereby releasing the diaphragm spring from elastic deformation, thereby disengaging the speed change clutch 32.

[0026] The control device 10 and the engine controller 20 are each composed of a computer unit equipped with a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory for storing backup data, etc., an input port, and an output port.

[0027] The ROM of these computer units stores various constants, various maps, and the like, as well as programs for causing these computer units to function as the control device 10 and the engine controller 20. That is, the CPU executes the programs stored in the ROM using the RAM as a working area, causing these computer units to function as the control device 10 and the engine controller 20 in this embodiment.

[0028] The control device 10 is connected to various devices such as the shift actuator, clutch actuator 33, and hydraulic control device 40 described above (not shown), as well as various sensors such as a crank angle sensor 50, a turbine rotation speed sensor 51, a clutch rotation speed sensor 52, a clutch position detection sensor 53, a lock-up hydraulic sensor 54, a vehicle speed sensor 55, and an accelerator sensor 56.

[0029] The hydraulic control device 40 controls the hydraulic pressure supplied to the lock-up clutch 35 and the clutch actuator 33 of the torque converter 30. The hydraulic control device 40 switches the lock-up clutch 35 between an engaged state and a released state by adjusting the magnitude of the hydraulic pressure supplied to the lock-up clutch 35 based on a command from the control device 10. The hydraulic control device 40 switches the variable speed clutch 32 between an engaged state and a released state by adjusting the magnitude of the hydraulic pressure supplied to the clutch actuator 33 based on a command from the control device 10.

[0030] The crank angle sensor 50 detects the rotation angle (hereinafter referred to as the "crank angle") of the crankshaft 21. The control device 10 calculates the engine rotation speed, which is the rotation speed of the engine 2 (the rotation speed of the crankshaft 21), based on the information indicating the crank angle input from the crank angle sensor 50.

[0031] The turbine rotation speed sensor 51 detects the rotation speed (hereinafter referred to as "turbine rotation speed") of the turbine shaft 36. The clutch rotation speed sensor 52 detects the rotation speed (hereinafter referred to as "clutch rotation speed") of the clutch disc 32b and the input shaft 37.

[0032] The clutch position detection sensor 53 detects the position of the release bearing in the transmission clutch 32 or the position of a part such as a release fork that moves in relation to the moving state of the release bearing (hereinafter referred to as the "clutch position"). The clutch position indicates the state of the transmission clutch 32 (disengaged state / half-clutch state / engaged state), and can also be considered to indicate the magnitude of the torque transmitted by the transmission clutch 32. The lock-up oil pressure sensor 54 detects the hydraulic oil pressure supplied to the lock-up clutch 35. In this embodiment, an example has been described in which the engaging oil pressure acting on the apply chamber is detected, but the oil pressure acting on the apply chamber may be estimated or detected based on the release oil pressure acting on the release chamber. The vehicle speed sensor 55 detects the vehicle speed, which is the speed of the vehicle 1. The accelerator sensor 56 detects the amount of depression of an accelerator pedal (not shown) by the driver. The accelerator sensor 56 may also detect the movement of a throttle valve that changes in conjunction with the amount of depression of the accelerator pedal.

[0033] The control device 10 has a function as a clutch control unit 101 that controls the shift clutch 32 by referring to a map (not shown) that defines the relationship between the clutch position and the clutch transmission torque (hereinafter also referred to as "clutch torque") based on the clutch position detected by the clutch position detection sensor 53, specifically, that controls the clutch actuator 33 so as to perform the clutch operation of the shift clutch 32. The clutch control unit 101 in this embodiment constitutes a control unit.

[0034] When changing gears, the control device 10 automatically performs clutch operation and shift operation by controlling the clutch actuator 33 and the shift actuator so as to switch the gear change clutch 32 from an engaged state to a disengaged state, then switch the gear in the transmission mechanism 31, and then switch the gear change clutch 32 from a disengaged state to an engaged state.

[0035] To perform the above-mentioned gear shift smoothly and without discomfort (without impairing drivability), it is desirable to control the turbine rotation speed of turbine shaft 36, which is the input member to gear shift clutch 32, so that it can be synchronized with the clutch rotation speed without shock when the clutch is engaged. Also, it is desirable to prevent the turbine rotation speed and engine rotation speed from revving up by controlling the turbine rotation speed to an ideal turbine rotation speed while gear shift clutch 32 is released, thereby preventing an increase in the time required for gear shifting and sluggish acceleration.

[0036] If the torque (turbine torque) input to the transmission clutch 32 is greater than the clutch torque, the transmission clutch 32 will slip excessively, causing the engine rotation speed to increase. Conversely, if the torque input to the transmission clutch 32 is smaller than the clutch torque, the transmission clutch 32 will not slip but will suddenly engage, causing a shock due to the action of the inertia (inertial force) on the engine 2 side.

[0037] Therefore, when engaging the variable speed clutch 32 in conjunction with a gear shift, it is preferable that the control device 10 determines the engine required torque, which is the torque required of the engine 2, according to the clutch torque and the target turbine rotation speed, which is a target value of the ideal turbine rotation speed. Also, it is preferable that there is no significant difference in the behavior of the vehicle between a gear shift with the lock-up clutch 35 engaged and a gear shift with the lock-up clutch 35 not engaged, so that the driver does not feel uncomfortable.

[0038] Here, when the lock-up clutch 35 is engaged, the crankshaft 21 and the turbine shaft 36 are directly connected, so the engine rotation speed and the above-mentioned turbine rotation speed match. Therefore, when performing a gear shift with the lock-up clutch 35 engaged, the control device 10 only needs to determine the engine required torque based on the target engine rotation speed, and can control the gear shift clutch 32 with the engine required torque as the "torque input to the gear shift clutch 32."

[0039] On the other hand, when the lock-up clutch 35 is released, the crankshaft 21 and the turbine shaft 36 transmit power through the fluid of the torque converter 30, so that the engine rotation speed and the turbine rotation speed do not match. For this reason, if the engine request torque is determined based on the target engine rotation speed as described above when the lock-up clutch 35 is released and the gear shift is performed, the turbine rotation speed, which is the rotation speed of the turbine shaft 36, which is the input member to the gear shift clutch 32, cannot be smoothly synchronized with the clutch rotation speed. In this case, the engine rotation speed may increase or a shock may occur as described above, which may impair drivability. In addition, since the driving force is significantly different, a large difference may occur in the acceleration of the vehicle, which may cause a sense of discomfort to the driver.

[0040] In this embodiment, when a gear shift is performed with the lock-up clutch 35 released, attention is focused on the turbine shaft 36, which is an input member to the gear shift clutch 32, and the turbine rotation speed is set as a control target, and the engine required torque is determined based on the turbine rotation speed. Specifically, when a gear shift is performed with the lock-up clutch 35 released, the control device 10 calculates a required value (input required torque) of the input torque of the torque converter 30 to be input to the torque converter 30 required to output the torque based on the target rotation speed of the turbine shaft 36, i.e., the target turbine rotation speed which is a target value of the turbine rotation speed, and the turbine required torque which is a required value of the torque (input torque of the gear shift clutch 32) transmitted from the turbine shaft 36 to the gear shift clutch 32, and calculates an engine torque corresponding to the input required torque of the torque converter 30 as the engine required torque. When the gear shift is performed, the engine 2 is controlled based on the engine required torque calculated above, and outputs the required engine torque. A method of calculating the engine required torque will be described later.

[0041] The control device 10 has a function as a lock-up clutch control unit 102 that controls the engagement or release of the lock-up clutch 35. For example, when a predetermined lock-up condition is established, the control device 10 executes lock-up control that controls the hydraulic control device 40 so as to switch the lock-up clutch 35 from a released state to an engaged state.

[0042] In this embodiment, the predetermined lock-up condition is, for example, when the vehicle speed is equal to or greater than a predetermined vehicle speed. The predetermined lock-up condition is not limited to this, and may be other conditions, or the state of the gear position and the vehicle speed may be the predetermined lock-up condition.

[0043] The engine controller 20 is connected to the control device 10 so as to exchange information with the control device 10, and controls the engine 2 based on the engine required torque calculated by the control device 10 as described above.

[0044] (Calculation method of engine required torque) Next, a method of calculating the engine required torque when a gear shift is performed in the control device 10 of this embodiment with the lock-up clutch 35 released will be described with reference to Figs.

[0045] In explaining the method of calculating the engine required torque, various parameters in the power transmission system of the vehicle 1 of this embodiment are specifically defined as follows, as shown in Fig. 2. In the following, parameters marked with "*" indicate target values ​​of parameters not marked with "*", and parameters marked with "r" indicate required values ​​of parameters not marked with "r".

[0046] Ne: Engine speed Ne*: Target engine speed Nt: Turbine rotation speed Nt*: Target turbine rotation speed Nc: Clutch rotation speed Te: Engine torque Ter: Engine torque requirement Ti: Impeller torque (input torque) Tir: Input torque requirement Tt: Turbine torque Ttr: Turbine required torque Tc: Clutch torque Tc*: Target clutch torque Ie: Engine inertia Ii: Imperial liner It: Turbine inertia Ic: Clutch inertia

[0047] Moreover, other parameters not explicitly shown in FIG. 2 are defined as follows. C: Capacity coefficient of the torque converter 30 SR: Speed ​​ratio τ: Torque ratio dNe / dt*: Target engine speed change amount ∂ωt / ∂t*: Target turbine rotation change amount

[0048] The speed ratio SR is the ratio (Nt* / Ne*) between the target engine speed Ne*, which is the input rotation speed to the torque converter 30, and the target turbine speed Nt*. The torque ratio τ is the ratio between the input torque and the output torque of the torque converter 30 (output torque / input torque). The target engine rotation change amount dNe / dt* is a value obtained by time-differentiating the target engine speed Ne*. The target turbine rotation change amount ∂ωt / ∂t* is a value obtained by partially differentiating the angular speed corresponding to the target turbine speed Nt*.

[0049] First, upon receiving outputs from various sensors such as the vehicle speed sensor 55 and the accelerator sensor 56, the control device 10 refers to a shift map based on the vehicle speed and the amount of depression of the accelerator pedal to determine whether a shift is necessary, and when it is determined that a shift is necessary, outputs a shift instruction to the clutch actuator 33. Then, the clutch actuator 33 that has received the shift instruction operates to switch the shift clutch 32 from "engaged state" to "disengaged state" to "engaged state." At this time, the driver's required acceleration level is estimated based on the vehicle speed and the amount of depression of the accelerator pedal, or the accelerator pedal depression speed, and the speed of the engagement operation ("disengaged state" to "engaged state") of the shift clutch 32 after the shift stage of the transmission mechanism 31 is changed and the magnitude of the driving force at the time of completion of engagement is determined. In addition, a target turbine rotation speed Nt* is calculated so that the turbine rotation speed Nt, which is the rotation speed of the turbine shaft 36 that is the input member to the variable speed clutch 32, can be synchronized with the clutch rotation speed Nc without shock when the clutch is engaged, and the turbine required torque Ttr is determined based on the calculated target turbine rotation speed Nt*.

[0050] Specifically, the turbine required torque Ttr is calculated by the control device 10 using the following equation. Ttr = Tc* + It(∂ωt / ∂t*)

[0051] The target clutch torque Tc* in the above formula is obtained from an acceleration request of the vehicle 1. For example, the control device 10 can obtain the target clutch torque Tc* from the accelerator opening by referring to a map in which the relationship between the accelerator opening and the target clutch torque Tc* is experimentally obtained in advance and stored in ROM. Note that the inertia It, which is the moment of inertia of the turbine shaft 36, can be obtained in advance from design data.

[0052] 3, the control device 10 calculates the impeller torque, i.e., the input torque Tir required to the torque converter 30, from the target turbine rotation speed Nt* and the turbine torque Ttr (step S1). Specifically, the control device 10 calculates the input torque Tir required to the torque converter 30 by referring to a first conversion map that has been previously calculated to determine the relationship between the turbine rotation speed Nt, the turbine torque Tt, and the input torque Ti of the torque converter 30. The first conversion map is stored in the ROM of the control device 10.

[0053] The first conversion map for calculating the input torque requirement Tir of the torque converter 30 can be created, for example, by the following procedure. In this embodiment, the input rotation speed to the torque converter 30 is the engine rotation speed Ne, and therefore, hereinafter, the input rotation speed to the torque converter 30 is referred to as the "engine rotation speed Ne."

[0054] For any input torque (impeller torque Ti) and any turbine rotation speed, 2 The engine speed Ne at the equilibrium point where the theoretical input torque calculated by "Nt / Ne" is equal to an arbitrary input torque is determined to be a single value. When the speed ratio SR is calculated from "Nt / Ne" at that time, the capacity coefficient C and torque ratio τ of the torque converter 30 are also determined from the torque converter characteristics. The torque converter characteristics are determined based on the specifications of the torque converter 30, such as the transmission torque capacity.

[0055] Here, the turbine torque Tt can be calculated by "Tt=Ti×τ". Therefore, the turbine torque Tt can be calculated from any input torque and turbine rotation speed. Therefore, by performing such calculations in advance and mapping the calculation results, the above-mentioned first conversion map is created, which can calculate the input required torque Tir to the torque converter 30 from the target turbine rotation speed Nt* and the turbine required torque Ttr.

[0056] The torque converter 30 qualitatively operates only at the balance point. Specifically, since the theoretical input torque is regarded as a load torque relative to the input torque of the torque converter 30, when the theoretical input torque exceeds the input torque, the input rotation speed (engine rotation speed Ne) of the torque converter decreases, and the theoretical input torque decreases. On the other hand, when the theoretical input torque is lower than the input torque, the input rotation speed (engine rotation speed Ne) of the torque converter increases, and the theoretical input torque increases, resulting in a qualitative operation only at the balance point.

[0057] The control device 10 calculates the target engine speed Ne* from the target turbine speed Nt* and the input torque request Tir to the torque converter 30 calculated in step S1 (step S2). Specifically, the control device 10 calculates the target engine speed Ne* by referring to a second conversion map that has been calculated in advance to determine the relationship between the turbine speed Nt, the input torque Ti to the torque converter 30, and the engine speed Ne. The second conversion map is stored in the ROM of the control device 10.

[0058] The second conversion map for calculating the target engine rotation speed Ne* can be created, for example, by the following procedure. As described above, for any input torque (impeller torque Ti) and turbine rotation speed, "C×Ne 2The engine speed Ne at which the theoretical input torque calculated by " is equal to an arbitrary input torque is determined to be one value. By mapping this determination result (calculation result), the above-mentioned second conversion map is created, which can calculate the target engine speed Ne* from the target turbine speed Nt* and the input torque requirement Tir to the torque converter 30. Note that the first and second conversion maps may be changed depending on environmental factors. For example, they may be switched according to the oil temperature in the torque converter, which changes the characteristics (capacity coefficient, torque ratio) of the torque converter 30.

[0059] In this embodiment, the control is established using two conversion maps, the first conversion map and the second conversion map, but calculation may be performed using one conversion map. Specifically, the above calculation may be performed in a similar manner, the engine speed Ne at the balance point between an arbitrary turbine torque Tt and an arbitrary turbine speed Nt may be calculated in advance and stored as a conversion map, and the target engine speed Ne* may be calculated directly from the target turbine speed Nt* and the input required torque Tir.

[0060] Next, the control device 10 calculates the target engine rotation change amount dNe / dt* by time-differentiating the target engine rotation speed Ne* calculated in step S2 (step S3).

[0061] Next, the control device 10 calculates the engine inertia torque "(dNe / dt*) x Ie" by multiplying the target engine rotation change amount dNe / dt* calculated in step S3 by the engine inertia Ie (step S4).

[0062] Next, the control device 10 calculates a feedforward term Te_FF of the engine required torque by adding the engine inertia torque "(dNe / dt*) x Ie" to the input required torque Tir to the torque converter 30 calculated in step S1 (step S5).

[0063] The control device 10 calculates the difference between the actual turbine rotation speed (hereinafter referred to as "actual turbine rotation speed") and the target turbine rotation speed Nt* used in the calculation in step S1, and corrects the engine required torque by feedback control (step S6). That is, the control device 10 calculates the feedback term Te_FB of the engine required torque. By performing the feedback control as described above, the control device 10 can suppress deterioration of the gear shift feeling even when deviations in the vehicle characteristics occur.

[0064] The control device 10 calculates the engine required torque Ter by adding up the feedforward term Te_FF calculated in step S5 and the feedback term Te_FB calculated in step S6 (step S7).

[0065] When a gear shift is performed with the lock-up clutch 35 disengaged, the control device 10 controls the engine 2 based on the engine required torque Ter calculated in step S7. As a result, even when a gear shift is performed with the lock-up clutch 35 disengaged, the engine torque can be controlled so that the turbine rotation speed, which is the rotation speed of the turbine shaft 36, which is the input member to the gear shift clutch 32, becomes an ideal target turbine rotation speed, and smooth synchronization can be achieved when the clutch is engaged.

[0066] As described above, the control device for a vehicle drive device according to this embodiment is configured to calculate the engine required torque Ter based on the target turbine rotation speed Nt* when a gear shift is performed with the lock-up clutch 35 disengaged. Also, the engine 2 is configured to be controlled based on the calculated engine required torque Ter when a gear shift is performed with the lock-up clutch 35 disengaged.

[0067] This makes it possible to prevent the variable speed clutch 32 from suddenly engaging without slipping, which would cause a shock due to the action of inertia (inertial force) on the engine 2 side. It is also possible to prevent the engine rotation speed from increasing and the occurrence of a shock.

[0068] Furthermore, since the above-mentioned shock and the increase in the turbine rotation speed and the engine rotation speed during the release of the shift clutch 32 can be prevented during the shift when the lock-up clutch 35 is not engaged, a smooth shift can be performed even when the lock-up clutch 35 is not engaged. This prevents the time required for the shift from being lengthened and prevents the occurrence of sluggish acceleration. Furthermore, since the control of this configuration can be used continuously regardless of whether the shift clutch 32 is being released or engaged, continuous control can be realized, and a step change in the engine required torque due to control switching or the like does not occur, so a smooth shift feeling can be obtained. By performing the above-mentioned feedback control, the control device 10 of this embodiment can suppress the deterioration of the shift feeling even when a deviation in the vehicle characteristics occurs.

[0069] In this way, the control device for a vehicle drive device in this embodiment can smoothly engage the shift clutch 32 and perform smooth gear changes without compromising drivability, even when the lock-up clutch 35 is not engaged.

[0070] In addition, the control device of the vehicle drive device in this embodiment is configured to calculate an input required torque Tir, which is a required value of the input torque input from the engine 2 to the torque converter 30, based on the target turbine rotation speed Nt* and the turbine required torque Ttr, and to calculate an engine torque corresponding to the input required torque Tir as the engine required torque Ter.

[0071] In addition, the control device for a vehicle drive device according to this embodiment calculates the input required torque Tir by referring to a first conversion map that defines the relationship between the turbine rotation speed Nt and the turbine torque Tt and the input torque Ti, and therefore can easily determine the optimal input required torque Tir.

[0072] Moreover, the control device for the vehicle drive device according to this embodiment is configured to calculate the target engine rotation speed Ne* based on the target turbine rotation speed Nt* and the required input torque Tir.

[0073] Although an embodiment of the invention has been disclosed, it will be apparent to one of ordinary skill in the art that modifications may be made thereto without departing from the scope of the invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0074] 1 vehicle 2 Engine 3 Automatic transmission (vehicle drive system) 4 Drive wheels 10 Control device 20 Engine Controller 21 Crankshaft 30 Torque converter 31 Transmission mechanism 32 Shift clutch 32a clutch wheel disc 32b clutch disc 33 Clutch actuator 35 Lock-up clutch 36 Turbine shaft 37 Input shaft 38 Output shaft 40 Hydraulic control device 50 Crank angle sensor 51 Turbine rotation speed sensor 52 Clutch rotation speed sensor 53 Clutch position detection sensor 54 Lockup oil pressure sensor 55 Vehicle speed sensor 56 Accelerator Sensor 101 Clutch control unit (control unit) 102 Lock-up clutch control unit Ter Engine torque requirement Ttr Turbine required torque Ti Input Torque Tir Input torque requirement Tc* Target clutch torque Ne* Target engine speed Nt* Target turbine speed

Claims

1. a torque converter with a lock-up clutch connected to the engine; a speed change mechanism that changes the rotation of the engine at a speed ratio corresponding to a gear position and outputs the changed rotation; a variable speed clutch that is provided between the torque converter and the speed change mechanism and that can be switched between an engaged state in which power is transmitted and a disconnected state in which power is disconnected; A clutch actuator that automatically operates the speed change clutch; A control device for a vehicle drive device comprising: A control unit is provided for controlling the driving of the clutch actuator, when performing a gear shift to switch the gear position while the lock-up clutch is released, the control unit calculates an engine required torque that is a required value of torque output from the engine based on a target turbine rotation speed that is a target rotation speed of a turbine shaft connected to the torque converter and the gear shift clutch; 2. The control device for a vehicle drive device, wherein the engine is controlled based on the engine required torque when the gear shift is performed.

2. 2. The control device for a vehicle drive device according to claim 1, wherein the control unit calculates an input required torque, which is a required value of an input torque input from the engine to the torque converter, based on the target turbine rotation speed and a turbine required torque, which is a required value of a turbine torque transmitted from the turbine shaft to the variable speed clutch, and calculates an engine torque corresponding to the input required torque as the engine required torque.

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