JP2019120290A - Drive unit for vehicle - Google Patents

Abstract

To provide a drive unit for a vehicle which makes an overshoot of engagement pressure hardly occur when boosting the engagement pressure up to hydraulic pressure for maintaining an engagement element in a complete engagement state, and can suppress the lowering of original pressure resulting from the overshoot.SOLUTION: When bringing an engagement element into a complete engagement state from a release state, an ECU performs engagement processing for boosting engagement pressure so that differential rotation at an input side of the engagement element and differential rotation at an output side are eliminated (t1 to t2), performs first processing (t2) for boosting the engagement pressure at a first boosting speed up to torque capacity pressure Pt which is higher than first hydraulic pressure P1 being the engagement pressure which has been supplied to the engagement element at a finish (t2) of the engagement processing, and lower than the upper-limit pressure Pim of the engagement pressure which can be supplied to the engagement element, and after a finish of the first processing, performs second processing (t2 to t3) for boosting the engagement pressure up to the upper-limit pressure Pim at a second boosting speed which is lower than the first boosting speed.SELECTED DRAWING: Figure 4

Description

  The present disclosure relates to a drive device for a vehicle mounted on a vehicle such as a car.

  Conventionally, for example, as a vehicle drive device suitable for use in a vehicle, a vehicle drive device using a belt-type continuously variable transmission mechanism provided with a primary pulley and a secondary pulley and a metal belt wound around these pulleys has become widespread doing. In a vehicle drive device equipped with such a continuously variable transmission mechanism, a forward-reverse switching device is mounted to switch the rotational direction of the driving force of the internal combustion engine according to the traveling direction of the vehicle and transmit it to the continuously variable transmission mechanism. There is something to be done. The forward / backward switching device includes, for example, a forward clutch that forms a transmission path of driving force in the rotational direction for advancing the vehicle when engaged, and a transmission path of driving force in the rotational direction for moving the vehicle backward when engaged. There is known a brake having a reverse brake (see Patent Document 1).

  In this vehicle drive device, for example, when one of the forward clutch or the reverse brake (hereinafter referred to as a start clutch) is switched from the release state to the full engagement state when the garage control is performed, the following Execute in the procedure. First, the hydraulic pressure output from the linear solenoid valve is supplied as the engagement pressure to the hydraulic servo of the start clutch, and the engagement pressure is gradually increased. Then, when the start clutch is completely engaged, the switching valve is switched to switch the engagement pressure supplied to the hydraulic servo from the output pressure of the linear solenoid valve to the modulator pressure. Thereby, the modulator pressure is directly supplied to the fully engaged start clutch, and the fully engaged state is maintained.

JP, 2011-247370, A

  However, in the vehicle drive device described in Patent Document 1, the engagement pressure supplied to the hydraulic servo is switched from the output pressure of the linear solenoid valve to the modulator pressure when the start clutch is completely engaged. The combined pressure will rise sharply. The sudden pressure increase of the engagement pressure may cause the engagement pressure to overshoot in the hydraulic servo, in which case the clutch is temporarily deformed by an excessive pressing force and operated by the overstroke of the piston The expansion of the oil chamber and the flow of the hydraulic oil exceeding the set amount into the hydraulic oil chamber may cause a temporary decrease in line pressure. When the belt clamping pressure of the continuously variable transmission mechanism is reduced due to the reduction of the line pressure, there is a possibility that belt slippage may occur.

  Therefore, when the engagement pressure is increased to a hydraulic pressure that maintains the engagement element in a completely engaged state, overshoot of the engagement pressure is less likely to occur, and a pressure drop of the original pressure due to the overshoot can be suppressed. It aims at providing a drive for vehicles.

  A vehicle drive device according to the present disclosure includes an input member drivingly connected to a drive source, an output member drivingly connected to a wheel, and an engagement element engaged and disengaged by supply and discharge of an engagement pressure, A transmission capable of transmitting power of the drive source to the wheel by forming a power transmission path by engagement of the engagement element, a hydraulic control device capable of supplying and discharging the engagement pressure, and the hydraulic control device A control unit controlled by an electrical signal, wherein the control unit eliminates differential rotation on the input side and the output side of the engagement element when the engagement element is completely engaged from the release state Engaging process for increasing the engaging pressure, and the engaging element being larger than the first hydraulic pressure, which is the engaging pressure supplied to the engaging element at the end of the engaging process, and the engaging element The engagement pressure to a second hydraulic pressure smaller than the upper limit pressure of the engagement pressure that can be supplied to the A first process of boosting at pressure speed is executed, and after the first process is completed, the engagement pressure is boosted to the upper limit pressure at a second pressure boosting speed that is slower than the first pressure boosting speed. Execute the process of

  According to the vehicle drive device, the control unit executes the first process to raise the engagement pressure at the first pressure increase speed when the engagement element is brought into the full engagement state from the release state. By executing the second process, the engagement pressure is boosted to the upper limit pressure at a second boosting speed that is slower than the first boosting speed. As a result, since the engagement pressure can be increased at a low speed when the pressure is increased to the upper limit pressure, overshooting of the engagement pressure can be achieved when the engagement pressure is increased to the hydraulic pressure that maintains the engagement element fully engaged. It can be made difficult to generate, and the pressure drop of the primary pressure caused by the overshoot can be suppressed.

FIG. 1 is a schematic view showing a skeleton of an automatic transmission according to a first embodiment. FIG. 1 is a hydraulic circuit diagram showing a hydraulic control device of an automatic transmission according to a first embodiment. It is a flow chart which shows the processing procedure of the automatic transmission concerning a 1st embodiment. It is a time chart which shows the processing procedure of the automatic transmission which concerns on each embodiment, (a) is 1st Embodiment, (b) is 2nd Embodiment. It is a flowchart which shows the process sequence of the automatic transmission which concerns on 2nd Embodiment.

First Embodiment
Hereinafter, the vehicle drive device according to the first embodiment will be described with reference to FIGS. 1 to 4A. In this embodiment, the case where the vehicle drive device is applied to, for example, an automatic transmission 3 mounted on the vehicle 1 and having the internal combustion engine 2 as a drive source is described. Further, in the present embodiment, the automatic transmission 3 is a so-called FF (front engine / front drive) type. However, the automatic transmission 3 is not limited to the FF type, and may be an FR (front engine rear drive) type.

  The vehicle 1 includes an internal combustion engine (drive source) 2, an automatic transmission 3, an ECU (control unit) 4 for controlling the automatic transmission 3, a hydraulic control device 5, wheels 8 (8L, 8R) and the like. Have. The internal combustion engine 2 is an internal combustion engine such as a gasoline engine or a diesel engine, for example, and is connected to the automatic transmission 3.

  The automatic transmission 3 includes an input shaft (input member) 31 of the automatic transmission 3, a starting device 10, an intermediate shaft 32, a forward / reverse switching device 20, a continuously variable transmission mechanism (transmission) 60 and a continuously variable transmission. An input shaft 33 of the transmission mechanism 60, a counter shaft (output member) 70, and a differential device 80 are provided. The input shaft 31, the starting device 10, the intermediate shaft 32, the forward / reverse switching device 20, the input shaft 33, and the primary pulley 61 of the continuously variable transmission mechanism 60 are coaxially arranged in order. The input shaft 31 of the automatic transmission 3 is drivingly connected to the internal combustion engine 2.

  The launch device 10 includes a torque converter (fluid transmission device) 11 and a lockup clutch 12 that can lock it up. The torque converter 11 is disposed coaxially with the input shaft 31 and can be drivably coupled to the continuously variable transmission mechanism 60. The torque converter 11 is disposed between a pump impeller 11a connected to the input shaft 31 of the automatic transmission 3, a turbine runner 11b to which the rotation of the pump impeller 11a is transmitted via oil which is a working fluid, and the like. And a stator 11 c whose rotation is restricted in one direction by a one-way clutch 11 d fixed to the case 30. The turbine runner 11 b is connected to the intermediate shaft 32. The lockup clutch 12 directly engages the front cover 12a and the intermediate shaft 32 by engagement to lock up the torque converter 11.

  The forward / reverse switching device 20 is coaxially disposed on the power transmission path in series with the torque converter 11 via the intermediate shaft 32 in series with the torque converter 11 and has one simple planetary gear SP. The sun gear 20s of the simple planetary gear SP is intermediate The ring gear 20r is fixed to the shaft 32, and is connected to the input shaft 33 of the continuously variable transmission mechanism 60. The forward / reverse switching device 20 further includes a forward clutch C1 interposed between the carrier 20c supporting the pinion 20p and the intermediate shaft 32, and a reverse brake B1 coupled with the carrier 20c. Therefore, the forward clutch C1 and the reverse brake B1 are disposed in series with the torque converter 11 in the power transmission path. The forward clutch C1 and the reverse brake B1 are respectively composed of engagement elements engaged and disengaged by supply and discharge of an engagement pressure.

  In a state in which the forward clutch C1 is engaged, the input rotation of the intermediate shaft 32 is input to the sun gear 20s and the carrier 20c, the simple planetary gear SP is integrally connected in a directly coupled state, and the input rotation is continuously variable from the ring gear 20r. It is transmitted to the mechanism 60. When the reverse brake B1 is engaged, the input rotation of the intermediate shaft 32 is input to the sun gear 20s and the rotation of the carrier 20c is fixed, and the reverse rotation reversed via the carrier 20c is the ring gear 20r. It is transmitted to the continuously variable transmission mechanism 60 more. That is, the automatic transmission 3 can transmit the power of the internal combustion engine 2 to the wheels 8 by forming a power transmission path by engagement of one of the forward clutch C1 and the reverse brake B1.

  The continuously variable transmission mechanism 60 is wound around a primary pulley 61 drivingly connected to the input shaft 33, a secondary pulley 62 drivingly connected to the output shaft 34 parallel to the input shaft 33, and both pulleys 61 and 62. A belt type continuously variable transmission having an endless belt (for example, any endless belt such as a metal push type belt, a metal pull type belt, and a metal ring) 63 and capable of continuously changing the transmission ratio It is configured.

  The primary pulley 61 has wall surfaces formed in a conical shape facing each other, and can be axially moved relative to the input shaft 33 with respect to the fixed sheave 61 a which is axially immovably fixed relative to the input shaft 33 The belt 63 is held by a groove having a V-shaped cross section formed by the fixed sheave 61a and the movable sheave 61b. On the back side of the movable sheave 61b of the primary pulley 61, a hydraulic servo 65 having a primary side hydraulic fluid chamber 65a is disposed. The primary pulley pressure Pa is supplied as a hydraulic pressure from the primary pulley pressure adjusting valve 53 of the hydraulic control device 5 to the primary side hydraulic fluid chamber 65a (see FIG. 2), and the movable sheave 61b of the primary pulley 61 is controlled by supply. And set the gear ratio.

  The secondary pulley 62 has wall surfaces formed in a conical shape facing each other, and can be axially moved relative to the output shaft 34 with respect to the fixed sheave 62 a which is axially immovably fixed relative to the output shaft 34 The belt 63 is held by a groove having a V-shaped cross section formed by the fixed sheave 62a and the movable sheave 62b. On the back side of the movable sheave 62b of the secondary pulley 62, a hydraulic servo 66 having a secondary hydraulic fluid chamber 66a is disposed. The secondary pulley pressure Pb is supplied as a hydraulic pressure from the secondary pulley pressure adjusting valve 54 of the hydraulic control device 5 to the secondary side hydraulic fluid chamber 66a (see FIG. 2), and the movable sheave 62b of the secondary pulley 62 is controlled by supply. Set the belt clamping pressure.

  In the present specification, to supply the hydraulic pressure to the hydraulic servo 65 of the movable sheave 61b of the primary pulley 61 is simply expressed as supplying the hydraulic pressure to the movable sheave 61b of the primary pulley 61. Supplying the hydraulic pressure to the hydraulic servo 66 of the movable sheave 62b is simply expressed as supplying the hydraulic pressure to the movable sheave 62b of the secondary pulley 62.

  The output gear 35 connected to the secondary pulley 62 by the output shaft 34 meshes with the driven gear 71 at one end of the counter shaft 70, and the drive gear 72 at the other end of the counter shaft 70 meshes with the ring gear 81 of the differential gear 80. It is done. Therefore, the output rotation that is continuously changed by the continuously variable transmission mechanism 60 is transmitted to the differential device 80 through the counter shaft 70, and the differential rotation of the left and right drive shafts 82L and 82R is absorbed by the differential device 80. It is outputted to the wheels 8L, 8R connected to the drive shafts 82L, 82R. Therefore, the continuously variable transmission mechanism 60 is capable of continuously variable transmission while drivingly connecting the internal combustion engine 2 and the wheels 8L and 8R.

  The automatic transmission 3 is provided with an oil pump (not shown) driven in conjunction with the internal combustion engine 2. The hydraulic pressure generated by the oil pump is regulated to the line pressure PL and the modulator pressure PLPM by a primary regulator valve and a modulator valve (not shown) provided in the hydraulic control device 5, respectively. Further, the hydraulic control device 5 is provided with a plurality of solenoid valves (not shown) and the like, and controls switching of the forward / backward switching device 20 and engagement / disengagement of the lockup clutch 12 using hydraulic pressure etc. Besides, the transmission gear ratio of the continuously variable transmission mechanism 60 is controlled as described later.

  The ECU 4 includes, for example, a CPU, a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port, and various control signals to the hydraulic control device 5, etc. Output the electrical signal of from the output port. The ECU 4 includes, for example, an accelerator opening sensor 41, an input-side rotational speed sensor 42 for detecting the rotational speed of the intermediate shaft 32, an output-side rotational speed sensor 43 for detecting the rotational speed of the countershaft 70, and a secondary pulley pressure. A secondary pulley pressure sensor 44 for detecting Pb is connected via an input port.

  The ECU 4 sets the target gear ratio of the continuously variable transmission mechanism 60 based on the accelerator opening detected by the accelerator opening sensor 41 and the vehicle speed calculated from the rotational speed detected by the output side rotational speed sensor 43. Then, in order to form a target gear ratio, the primary control pressure PSLP from the primary control pressure solenoid valve SLP is adjusted, and the rotational speed and output side of the intermediate shaft 32 and the input shaft 33 detected by the input side rotational speed sensor 42 The actual gear ratio is calculated from the ratio to the rotational speed of the output shaft 34 calculated from the rotational speed of the counter shaft 70 detected by the rotational speed sensor 43.

  Next, the hydraulic control device 5 of the automatic transmission 3 according to the present embodiment will be described with reference to FIG. In the present embodiment, there is only one actual spool in each valve, but in order to explain the switching position or control position of the spool position, the state of the right half shown in FIG. The left half state "left half position".

  The hydraulic control device 5 is constituted of, for example, a valve body, and adjusts the hydraulic pressure generated by an oil pump (not shown) to the line pressure PL based on the throttle opening degree by the primary regulator valve. The hydraulic control device 5 includes a line pressure modulator valve 50, a manual valve 51, a primary control pressure solenoid valve SLP, a primary pulley pressure regulation valve 53, a secondary control pressure solenoid valve SLS, and a secondary pulley pressure regulation valve 54. And a linear solenoid valve SLC. The hydraulic control device 5 includes a hydraulic servo 55 operated hydraulically and capable of engaging and disengaging the forward clutch C1, a hydraulic servo 56 operated hydraulically and capable of engaging and disengaging the reverse brake B1, and a hydraulic servo 65 for the primary pulley 61. , And hydraulic servo 66 of the secondary pulley 62.

  The line pressure modulator valve 50 regulates the line pressure PL to generate a modulator pressure (source pressure) PLPM which is a constant pressure lower than the line pressure PL.

  The manual valve 51 includes a spool 51p mechanically or electrically moved by operation of a shift lever (not shown), an input port 51a to which the hydraulic pressure PSLC is supplied from the linear solenoid valve SLC, and the spool 51p has a D (drive) range The output port 51b outputs the hydraulic pressure PSLC as the forward range pressure PD in the position, and the output port 51c outputs the hydraulic pressure PSLC as the reverse range pressure PR when the spool 51p is in the R (reverse) range position. .

  The primary control pressure solenoid valve SLP has an input port SLPa to which the modulator pressure PLPM is input, and an output port SLPb communicated with the first hydraulic fluid chamber 53a of the primary pulley pressure regulating valve 53. The primary control pressure solenoid valve SLP supplies the primary control pressure PSLP to the primary pulley pressure regulating valve 53, whereby the primary pulley pressure supplied from the primary pulley pressure regulating valve 53 to the hydraulic servo 65 of the continuously variable transmission mechanism 60 Adjust the pressure of Pa.

  The primary pulley pressure adjusting valve 53 has a first hydraulic fluid chamber 53a for inputting the primary control pressure PSLP in a direction to press the spool 53p to the left half position, and the spool 53p in the right half position against the pressing spring 53s. The second hydraulic fluid chamber 53b inputs the primary pulley pressure Pa in the direction of pressing, the input port 53c inputs the line pressure PL, and the hydraulic pressure servo 65 of the primary pulley 61 and the primary pulley pressure Pa after pressure adjustment. And an output port 53d for supplying the second hydraulic oil chamber 53b. The primary pulley pressure adjusting valve 53 adjusts the magnitude of the primary pulley pressure Pa, which is regulated based on the line pressure PL, according to the magnitude of the primary control pressure PSLP.

  The secondary control pressure solenoid valve SLS has an input port SLSa to which the modulator pressure PLPM is input, and an output port SLSb communicated with the first hydraulic fluid chamber 54a of the secondary pulley pressure regulating valve 54. The secondary control pressure solenoid valve SLS supplies the secondary control pressure PSLS to the secondary pulley pressure adjusting valve 54, whereby the secondary pulley pressure supplied from the secondary pulley pressure adjusting valve 54 to the hydraulic servo 66 of the continuously variable transmission mechanism 60 Pressure regulation of Pb.

  The secondary pulley pressure adjusting valve 54 has a first hydraulic fluid chamber 54a for inputting the secondary control pressure PSLS in the direction of pressing the spool 54p to the left half position, and the spool 54p in the right half position against the pressing spring 54s. The hydraulic oil servo 66 of the secondary pulley 62 and the second hydraulic oil chamber 54b for inputting the secondary pulley pressure Pb in the direction of pressing action, the input port 54c for inputting the line pressure PL, and the secondary pulley pressure Pb after pressure adjustment. And an output port 54d for supplying the second hydraulic oil chamber 54b. The secondary pulley pressure regulating valve 54 adjusts the magnitude of the secondary pulley pressure Pb that is regulated based on the line pressure PL, based on the magnitude of the secondary control pressure PSLS.

  The linear solenoid valve SLC has an input port SLCa to which the modulator pressure PLPM is input, and an output port SLCb communicated with the input port 51 a of the manual valve 51. The linear solenoid valve SLC freely regulates and controls the modulator pressure PLPM input from the input port SLCa and outputs it from the output port SLCb, and the forward range pressure PD or the reverse range pressure PR is advanced clutch via the manual valve 51 It is generated as the engagement pressure of C1 or the reverse brake B1. Therefore, in the present embodiment, the hydraulic control device 5 regulates the forward range pressure PD, the reverse range pressure PR, the primary pulley pressure Pa, and the secondary pulley pressure Pb from the modulator pressure PLPM, which is a common source pressure.

  Next, an outline of the operation of the ECU 4 of the present embodiment will be described. The ECU 4 controls the speed of the continuously variable transmission 60 by transmitting control signals to the primary control pressure solenoid valve SLP and the secondary control pressure solenoid valve SLS. The ECU 4 transmits and receives a control signal to the linear solenoid valve SLC in response to the operation of the shift lever and the accelerator pedal (not shown), thereby engaging and disengaging the forward clutch C1 or the reverse brake B1 of the forward / reverse switching device 20. , Switches the forward and backward movement of the vehicle 1.

  The ECU 4 performs an engagement process, a capacity securing process (first process), and a gradual increase process (second process) when the forward clutch C1 or the reverse brake B1 is completely engaged from the release state. And in order. In the engagement processing, the ECU 4 gradually raises the forward range pressure PD or the reverse range pressure PR by sweep control, and engages so that the differential rotation on the input side and the output side of the forward clutch C1 or the reverse brake B1 disappears. Boost the pressure. The ECU 4 determines that the differential rotation on the input side and the output side of the forward clutch C1 or the reverse brake B1 is less than or equal to a predetermined value and is substantially eliminated, for example, or a predetermined time after the start of the engagement process. The engagement process is ended at timings such as when e. The engagement pressure supplied to the forward clutch C1 or the reverse brake B1 at the end of the engagement process is taken as a first hydraulic pressure P1 (see FIG. 4A).

  When the ECU 4 determines that it is time to finish the engagement process, the ECU 4 executes the capacity securing process, and the torque range pressure PD (second oil pressure) at the first boost speed of the forward range pressure PD or the reverse range pressure PR. Boost rapidly to Pt. The torque capacity pressure Pt here is larger than the first hydraulic pressure P1 and smaller than an upper limit pressure Plim to be described later. The torque capacity pressure Pt is a hydraulic pressure that can always ensure the torque capacity required of the forward clutch C1 or the reverse brake B1. The torque capacity is a torque capacity required for the forward clutch C1 or the reverse brake B1 at a certain point, and in the present embodiment, the safety factor (a margin (a margin And is varied based on, for example, an accelerator opening degree, an engine rotational speed, a vehicle speed, and the like. Therefore, the torque capacity pressure Pt supplied to the hydraulic servos 65 and 66 of the forward clutch C1 or the reverse brake B1 to obtain the torque capacity required for the forward clutch C1 or the reverse brake B1 is also due to the fluctuation of the torque capacity. It fluctuates with it.

  The ECU 4 boosts the pressure to the upper limit pressure Plim by the sweep control of the second boosting speed at which the forward range pressure PD or the reverse range pressure PR is slower than the first boosting speed in the slow rising process. The upper limit pressure Plim here is a hydraulic pressure that is larger than the maximum torque capacity pressure Pt, and is a hydraulic pressure that can be supplied to the forward clutch C1 or the reverse brake B1, and is a preset fixed pressure unique to the vehicle 1 And In addition, the second pressure increase speed is appropriately set based on, for example, the clutch stiffness of the forward clutch C1 or the reverse brake B1, the pump capacity for generating the source pressure of the hydraulic pressure, the engine rotational speed, the oil temperature, etc. Ru.

  Next, the specific processing procedure of the ECU 4 will be described in detail along the flowchart shown in FIG. 3 and the time chart shown in FIG. 4 (a). Here, a case will be described where the vehicle 1 equipped with the automatic transmission 3 is garage-controlled, the shift range is switched from the N (neutral) range to the D range, and the garage control is ended. In FIG. 4A, the engagement pressure indicates a command value output from the ECU 4 to the linear solenoid valve SLC. Further, although the engagement pressure supplied to the hydraulic servo 55 of the forward clutch C1 is the forward range pressure PD, that is, the hydraulic pressure PSLC output from the linear solenoid valve SLC, it is simply engaged in the drawings and the following description. It is written as combined pressure. In addition, although the case where the N range is switched to the D range is described below, the processing procedure is the same except that the traveling direction of the vehicle 1 is different also in the case where the N range is switched to the R range. .

  First, during garage control, a shift operation is performed, and the shift range is switched from the N range to the D range (t0 in FIG. 4A). When the shift range is switched, the manual valve 51 is switched to the D range, the linear solenoid valve SLC communicates with the hydraulic servo 55 of the forward clutch C1, and the hydraulic pressure PSLC output from the linear solenoid valve SLC is the forward range pressure PD. As the hydraulic servo 55 can be supplied. At this time, the hydraulic pressure PSLC (engagement pressure) supplied from the linear solenoid valve SLC is a predetermined release hydraulic pressure P0, and the ECU 4 executes the fast fill control to engage the forward clutch C1. Then, the hydraulic pressure PSLC is boosted, and after the standby hydraulic pressure (t0 to t1 in FIG. 4A), the pressure is gradually boosted by the sweep control (engagement processing, step S1 in FIG. 3, t1 in FIG. 4A). t2).

  The ECU 4 determines whether the differential rotation on the input side and the output side of the forward clutch C1 has disappeared, that is, whether the differential rotation is equal to or less than a predetermined value (step S2 in FIG. 3). In this embodiment, when the differential rotation on the input side and the output side of the forward clutch C1 is equal to or less than a predetermined value, it is determined that the differential rotation is substantially eliminated. The ECU 4 determines, based on the rotational speed detected by the input side rotational speed sensor 42 and the rotational speed detected by the output side rotational speed sensor 43, whether the differential rotation is equal to or less than a predetermined value. When the ECU 4 determines that the differential rotation is not equal to or less than the predetermined value, the sweep control is continued (step S1 in FIG. 3). If the ECU 4 determines that the differential rotation is equal to or less than the predetermined value, it determines that the forward clutch C1 is almost completely engaged, and ends the garage control (step S3 in FIG. 3, step (a) in FIG. 4). t2). The ECU 4 sets the engagement pressure at the time when it is determined that the differential rotation is equal to or less than the predetermined value as the first hydraulic pressure P1. After this, the ECU 4 executes processing as normal control, not garage control.

  The ECU 4 determines whether the engagement pressure at that time is less than the torque capacity pressure Pt at that time (step S4 in FIG. 3, t2 in FIG. 4A). The engagement pressure at that time is initially the first hydraulic pressure P1. When the ECU 4 determines that the engagement pressure is less than the torque capacity pressure Pt, it boosts the engagement pressure to the torque capacity pressure Pt (capacity securing process, step S5 in FIG. 3, t2 in FIG. 4A). . At this time, the speed at which the engagement pressure is increased to the torque capacity pressure Pt is the first pressure increase speed, for example, a step-like rapid pressure increase.

  Here, for example, it is assumed that the engagement pressure is rapidly increased to the upper limit pressure Plim at t2 in FIG. 4A (thick dotted line in FIG. 4A). In this case, there is a possibility that the engagement pressure may overshoot in the hydraulic servo 55 by rapidly increasing the engagement pressure to the upper limit pressure Plim, and then the advancing clutch C1 is temporarily pushed by an excessive pressing force. As a result, the hydraulic pressure chamber expands due to the overstroke of the piston, and the hydraulic pressure exceeding the set amount flows into the hydraulic pressure chamber, which may temporarily reduce the modulator pressure PLPM or the line pressure PL. . As the modulator pressure PLPM decreases, the original pressure of the secondary control pressure solenoid valve SLS decreases, the secondary control pressure PSLS decreases, and the secondary pulley pressure Pb adjusted by the secondary pulley pressure adjustment valve 54 decreases. Alternatively, there is a possibility that the secondary pulley pressure Pb after pressure adjustment may decrease by the decrease of the line pressure PL. Therefore, the belt clamping pressure of the continuously variable transmission mechanism 60 may be reduced, which may cause belt slippage.

  In order to solve this, in the automatic transmission 3 of the present embodiment, the engagement pressure overshoots by preventing the engagement pressure from being rapidly increased to the upper limit pressure Plim after the forward clutch C1 is completely engaged. It is hard to occur. Therefore, the ECU 4 determines whether the engagement pressure boosted by the capacity securing process is equal to or higher than the upper limit pressure Plim (step S6 in FIG. 3, t2 in FIG. 4A). If the ECU 4 determines that the engagement pressure boosted by the capacity securing process is not the upper limit pressure Plim or more, or if the engagement pressure is not less than the torque capacity pressure Pt in step S4 of FIG. The pressure is gradually increased by sweep control (slow pressure increase processing, step S7 in FIG. 3, t2 to t3 in FIG. 4A). The sweep control here is processed at a second boosting speed that is slower than the first boosting speed. As a result, since the engagement pressure can be increased at a low speed when the pressure is increased to the upper limit pressure Plim, the engagement pressure is increased when the engagement pressure is increased to the oil pressure that maintains the forward clutch C1 in the completely engaged state. It is possible to make it difficult to generate a chute and to suppress a pressure drop of the modulator pressure PLPM or the line pressure PL caused by the overshoot. In the present embodiment, the ECU 4 sets a pressure increase gradient in the gradual increase process, and increases the engagement pressure to the upper limit pressure Plim by the pressure increase gradient.

  The ECU 4 determines whether the engagement pressure is equal to or higher than the upper limit pressure Plim as the engagement pressure increases due to the gradual increase processing (step S8 in FIG. 3 and t2 to t3 in FIG. 4A). If the ECU 4 determines that the engagement pressure is equal to or higher than the upper limit pressure Plim, or if it determines that the engagement pressure is equal to or higher than the upper limit pressure Plim in step S6 of FIG. The engagement pressure is maintained at the upper limit pressure Plim to execute steady-state pressure control (step S9 in FIG. 3, t3 in FIG. 4A). If the ECU 4 determines in step S8 of FIG. 3 that the engagement pressure is not the upper limit pressure Plim or more, it determines again whether the engagement pressure is less than the torque capacity pressure Pt (FIG. 3). Step S4).

  As described above, according to the automatic transmission 3 of the present embodiment, the ECU 4 executes the capacity securing process to set the engagement pressure to the first when the forward clutch C1 is brought into the full engagement state from the release state. After boosting at the boosting speed, the engagement pressure is boosted to the upper limit pressure Plim at the second boosting speed that is slower than the first boosting speed by executing the gentle rising process. As a result, since the engagement pressure can be increased at a low speed when the pressure is increased to the upper limit pressure Plim, an overshoot of the engagement pressure is unlikely to occur when the engagement pressure is increased to the upper limit pressure Plim. Thus, it is possible to suppress the pressure drop of the modulator pressure PLPM and the line pressure PL caused by the overshoot.

  Further, according to the automatic transmission 3 of the present embodiment, the ECU 4 sets a pressure rising gradient in the gradual rising process, and boosts the engagement pressure by the pressure rising gradient until reaching the upper limit pressure Plim. For this reason, since the boosting process can be easily performed, an increase in load on the ECU 4 can be suppressed.

  In the automatic transmission 3 of the present embodiment described above, the engagement of the forward clutch C1 in the garage control has been described, but the present invention is not limited thereto. For example, the present invention can be applied to the engagement of a clutch or a brake other than garage control. Further, in the present embodiment, although the processing procedure in which the comparison determination between the engagement pressure and the torque capacity is not performed in the engagement processing has been described, the present invention is not limited thereto. For example, the ECU 4 engages in the engagement processing. When the pressure becomes equal to or higher than the torque capacity pressure Pt, the execution of the capacity securing process may be stopped to execute the gradual increase process.

  Further, in the automatic transmission 3 of the present embodiment, the ECU 4 sets the pressure increase gradient for increasing the engagement pressure in the gradual increase process, but the invention is not limited thereto. For example, the pressure may be increased in a curved shape or may be increased stepwise in steps.

Second Embodiment
Next, a second embodiment will be described in detail with reference to FIGS. 4 (b) and 5. This embodiment differs from the first embodiment in that the ECU 4 executes the capacity securing process and the slow increase process when the torque capacity pressure Pt exceeds the engagement pressure in the slow increase process. There is. However, since the other configuration is the same as that of the first embodiment, the reference numerals are the same, and the detailed description will be omitted.

  A specific processing procedure of the ECU 4 in the present embodiment will be described in detail along the flowchart shown in FIG. 5 and the time chart shown in FIG. 4 (b). Note that steps S1 to S7 of the flowchart shown in FIG. 5 and t2 of the time chart shown in FIG. 4B are the same as in the first embodiment, and thus the description thereof is omitted.

  The ECU 4 determines whether the engagement pressure at that time is less than the torque capacity pressure Pt at that time after execution of the gradual pressure increase processing (step S7 in FIG. 5) (step S10 in FIG. 5, FIG. 4 (b) after t2). That is, the ECU 4 constantly calculates the torque capacity pressure and compares the engagement pressure. Here, for example, the torque capacity pressure Pt may increase from the initial torque capacity pressure Pt1 to the torque capacity pressure Pt2 exceeding the engagement pressure because the accelerator opening degree becomes large during execution of the gradual pressure increase processing. In this case, when the torque capacity pressure Pt2 exceeds the engagement pressure, that is, when it is determined that the engagement pressure is less than the torque capacity pressure Pt2, the ECU 4 cancels the execution of the gradual pressure increase processing and secures the capacity again The process is executed to boost the engagement pressure to the torque capacity pressure Pt2 (capacity securing process, step S11 in FIG. 5, thick solid line t21 in FIG. 4B). At this time, the speed at which the engagement pressure is increased to the torque capacity pressure Pt2 is the first pressure increase speed, for example, a step-like rapid pressure increase.

  Then, the ECU 4 determines whether the engagement pressure at that time is equal to or greater than the upper limit pressure Plim (step S12 in FIG. 5, thick solid line after t21 in FIG. 4B). Similarly, when the ECU 4 determines in step S10 of FIG. 5 that the engagement pressure is not less than the torque capacity pressure Pt2, the ECU 4 determines whether the engagement pressure is equal to or higher than the upper limit pressure Plim (step S12 in FIG. 5). , Bold dotted line after t21 in FIG. If the ECU 4 determines that the engagement pressure is equal to or higher than the upper limit pressure Plim, the ECU 4 ends the pressure increase of the engagement pressure and maintains the engagement pressure at the upper limit pressure Plim (step S9 in FIG. 5, FIG. 4B). Thick solid line t22, thick dotted line t3). When the ECU 4 determines in step S12 of FIG. 5 that the engagement pressure is not the upper limit pressure Plim or more, the ECU 4 executes a gradual pressure increase process (step S7 of FIG. 5).

  As described above, the automatic transmission 3 of this embodiment can also increase the engagement pressure at a low speed when the engagement pressure is increased to the upper limit pressure Plim. Therefore, the engagement pressure is increased to the upper limit pressure Plim for the forward clutch C1. In this case, overshooting of the engagement pressure is less likely to occur, and pressure drops in the modulator pressure PLPM and the line pressure PL due to the overshoot can be suppressed.

  Further, according to the automatic transmission 3 of the present embodiment, when the torque capacity pressure Pt exceeds the engagement pressure in the gradual increase process, the ECU 4 executes the capacity securing process to execute the gradual increase process. It is possible to cope with the fluctuation of the torque capacity during the rising process. As a result, for example, the overshoot of the engagement pressure can be made less likely to occur even when the accelerator pedal is depressed during the gradual increase processing.

  The present embodiment at least includes the following configuration. The vehicle drive device (1) of the present embodiment includes an input member (31) drivingly connected to the driving source (2), an output member (70) drivingly connected to the wheel (8), and an engaging pressure An engagement element (C1, B1) engaged and disengaged by supply and discharge, and a power transmission path is formed by engagement of the engagement element (C1, B1) to motive power of the drive source (2) A transmission (60) that can be transmitted to the wheel (8), a hydraulic control unit (5) that can supply and discharge the engagement pressure, and a control unit (4) that controls the hydraulic control unit (5) by electrical signals And the control unit (4) sets the input side and the output side of the engagement element (C1, B1) when bringing the engagement element (C1, B1) from the release state into the full engagement state. Engagement processing for increasing the engagement pressure so as to eliminate the differential rotation, and at the end of the engagement processing 1) is larger than the first oil pressure (P1) which is the engagement pressure supplied to the above, and is higher than the upper limit pressure (Plim) of the engagement pressure which can be supplied to the engagement element (C1, B1) A first process of boosting the engagement pressure at a first boosting speed is executed to a small second hydraulic pressure (Pt, Pt1, Pt2), and after the first process is completed, the first boosting speed is set to be higher than the first boosting speed. A second process of boosting the engagement pressure to the upper limit pressure (Plim) at a slow second boosting speed is executed.

  According to this configuration, the control unit (4) executes the first process (capacity securing process) when the engaging element (C1, B1) is brought into the full engagement state from the release state, and the engagement pressure is achieved. By boosting the pressure at a first boosting speed and then performing a second process (slow rise process), the engagement pressure is increased to the upper limit pressure (Plim) at a second boosting speed that is slower than the first boosting speed. Boost. As a result, the engagement pressure can be increased at a low speed when the engagement pressure is increased to the upper limit pressure (Plim). Therefore, when the engagement pressure is increased to the oil pressure that maintains the engagement elements (C1, B1) in the full engagement state. The overshoot of the engagement pressure is less likely to occur, and the pressure drop of the original pressure caused by the overshoot can be suppressed.

  In the vehicle drive device (1) of the present embodiment, the second hydraulic pressure (Pt, Pt1, Pt2) is a hydraulic pressure in which a margin is added to the torque capacity pressure required for the engagement element (C1, B1). And the control unit (4) increases the torque capacity pressure required of the engagement element (C1, B1) during execution of the second process to boost the second hydraulic pressure (Pt1). When the engagement pressure being boosted toward the upper limit pressure (Plim) is exceeded, the execution of the second process is stopped and the first process is executed again, and the engagement during the boost is performed. After the combined pressure reaches the boosted second hydraulic pressure (Pt2), the second process is performed again. According to this configuration, it is possible to cope with the fluctuation of the torque capacity during the gradual increase processing. As a result, for example, the overshoot of the engagement pressure can be made less likely to occur even when the accelerator pedal is depressed during the gradual increase processing.

  Further, in the vehicle drive device (1) of the present embodiment, the control unit (4) performs the engagement process when the engagement pressure becomes equal to or higher than the second hydraulic pressure (Pt, Pt1, Pt2). Stops the execution of the first process and executes the second process. According to this configuration, even when the engagement pressure becomes equal to or higher than the torque capacity pressure in the engagement process, overshoot of the engagement pressure is less likely to occur, and the pressure drop of the original pressure caused by the overshoot is reduced. It can be suppressed.

  Further, in the vehicle drive device (1) of the present embodiment, the control unit (4) sets a boosting gradient in the second process, and boosts the voltage until the boosting gradient reaches the upper limit pressure (Plim). Do. According to this configuration, since the boosting process can be easily performed, an increase in the load of the control unit (4) can be suppressed.

  In the vehicle drive device (1) of the present embodiment, the transmission (60) includes a primary pulley (61) drivingly connected to the input member (31) and a driving connection to the output member (70). Secondary pulley (62), a belt (32) wound around the primary pulley (61) and the secondary pulley (62), and the primary pulley (61) by supplying a primary pulley pressure (Pa) Primary hydraulic fluid chamber (65a) for setting the gear ratio by pressing and controlling the movable sheave (61b) and the movable sheave (62b) of the secondary pulley (62) by supplying the secondary pulley pressure (Pb) A hydraulic pressure control device (60) having a secondary side hydraulic fluid chamber (66a) for pressing and controlling the belt to set the belt clamping pressure; (5), pressure regulating the engagement pressure and the secondary pulley pressure the (Pb) from a common source pressure (PLPM). According to this configuration, the occurrence of the belt slippage of the continuously variable transmission mechanism (60) due to the pressure drop of the primary pressure (PLPM) due to the overshoot is effectively prevented by making the overshoot of the engagement pressure difficult to occur. It can be suppressed.

2 Internal combustion engine (drive source)
3 Automatic transmission (drive for vehicle)
4 ECU (control unit)
5 hydraulic control unit 8 wheels 31 input shaft (input member)
60 Continuously variable transmission mechanism (transmission)
61 Primary pulley 61b Movable sheave 62 Secondary pulley 62b Movable sheave 63 Belt 65a Primary side hydraulic fluid chamber 66a Secondary side hydraulic fluid chamber 70 Counter shaft (output member)
B1 Reverse brake (engagement element)
C1 Forward clutch (engagement element)
P1 1st oil pressure Pa Primary pulley pressure Pb Secondary pulley pressure Plim Upper limit pressure PLPM Modulator pressure (source pressure)
Pt torque capacity pressure (second oil pressure)

Claims (5)

It has an input member drivingly connected to a drive source, an output member drivingly connected to a wheel, and an engagement element engaged and disengaged by supply and discharge of an engagement pressure, and power transmission by engagement of the engagement element A transmission capable of transmitting the power of the drive source to the wheels by forming a path;
A hydraulic control device capable of supplying and discharging the engagement pressure;
A control unit that controls the hydraulic control device by an electrical signal;
The control unit is configured to increase the engagement pressure so that the differential rotation on the input side and the output side of the engagement element is eliminated when the engagement element is completely released from the release state. And an upper limit pressure of the engagement pressure capable of being supplied to the engagement element, which is larger than the first oil pressure which is the engagement pressure supplied to the engagement element at the end of the engagement process A second processing step of boosting the engagement pressure at a first boosting speed to a second hydraulic pressure which is also smaller than the first hydraulic pressure, and after the first processing is completed, the second boosting processing is slower than the first boosting speed A vehicle drive device that executes a second process of increasing the engagement pressure to the upper limit pressure at a speed. The second hydraulic pressure is a hydraulic pressure obtained by adding a margin to the torque capacity pressure required for the engagement element,
The control unit is configured to increase the torque capacity pressure required of the engagement element during execution of the second process to increase the second hydraulic pressure and to increase the engagement pressure toward the upper limit pressure. If the pressure is exceeded, the execution of the second process is stopped and the first process is executed again, and the engagement pressure being boosted reaches the second hydraulic pressure after boosting, and then the second process is resumed. The vehicle drive device according to claim 1, wherein the second process is performed.   The control unit suspends the execution of the first process and executes the second process when the engagement pressure becomes equal to or higher than the second hydraulic pressure in the engagement process. Or 2. The vehicle drive device according to 2.   The vehicle drive device according to any one of claims 1 to 3, wherein the control unit sets a boosting gradient in the second process and boosts the pressure by the boosting gradient until the upper limit pressure is reached. The transmission is supplied with a primary pulley drivingly connected to the input member, a secondary pulley drivingly connected to the output member, a belt wound around the primary pulley and the secondary pulley, and a primary pulley pressure. The primary side hydraulic fluid chamber that controls the pressure on the movable sheave of the primary pulley to set the gear ratio, and the secondary pulley pressure is supplied to the belt to control the belt clamping pressure on the movable sheave of the secondary pulley. A continuously variable transmission mechanism having a secondary side hydraulic fluid chamber to be set;
The vehicle hydraulic drive system according to any one of claims 1 to 4, wherein the hydraulic pressure control device regulates the engagement pressure and the secondary pulley pressure from a common source pressure.

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