JP5807590B2 - Control device for automatic transmission for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for an automatic transmission mounted on a hybrid vehicle or the like, and more specifically, an engagement / disengagement state of a first friction engagement element disposed between an internal combustion engine and an automatic transmission mechanism, and automatic The present invention relates to a control device for an automatic transmission for a hybrid vehicle that controls an engagement / disengagement state of a second friction engagement element disposed in a transmission mechanism.

  For example, the automatic transmission transmits the output of the internal combustion engine to an automatic transmission mechanism that forms a plurality of shift stages via a torque converter. In order to improve transmission efficiency, a configuration is also known in which a lockup clutch is provided between the internal combustion engine and the automatic transmission mechanism, and the internal combustion engine and the automatic transmission mechanism are directly connected depending on the running state.

  In the case of a structure having such a lockup clutch, the lockup clutch may remain locked (directly connected) for some reason. For this reason, an apparatus provided with means for detecting an abnormality of the lockup clutch has been proposed. In the case of this device, the difference in the rotational speed between the output shaft of the internal combustion engine and the input shaft of the automatic transmission mechanism to which the output shaft of the lockup clutch is connected in a state where an off signal for releasing the lockup clutch is output. Is detected. When the difference in rotational speed between the output shaft and the input shaft is small even though the lock-up clutch is turned off, it is detected that the lock-up clutch is abnormal (see Patent Document 1).

  In addition, when the internal combustion engine is stopped during traveling and EV traveling is performed by the motor, if the gear position of the automatic transmission mechanism is a low speed stage such as the first to third forward speeds, a start clutch is provided in preparation for the start of the internal combustion engine. A device for engaging is proposed (see Patent Document 2).

JP 2003-287123 A JP 2010-223399 A

  However, in the hybrid vehicle described in Patent Document 2 described above, when EV traveling is performed in which the internal combustion engine is stopped and the motor is traveling from the state in which the lockup clutch is on during traveling, the torque and the rotational speed of the internal combustion engine are performed. Therefore, the difference in rotational speed between the output shaft of the internal combustion engine and the input shaft of the automatic transmission mechanism may not open even if the lockup clutch is off. For this reason, the apparatus described in Patent Document 1 described above may not be able to detect abnormality of the lockup clutch.

  Here, as in the vehicle described in the above-mentioned Patent Document 2, in order to smoothly switch from the state in which the internal combustion engine is stopped to the travel by the internal combustion engine, even if the internal combustion engine is stopped, The clutch may be in an engaged state. In such a case, if the starter motor is started by the starter motor due to a decrease in the charge amount of the battery or the like while the vehicle is stopped while the lockup clutch is locked, the output of the starter motor is locked up. It may be transmitted to the wheels via the clutch and the engaged clutch in the automatic transmission mechanism, which may cause the driver to feel uncomfortable.

  Therefore, the present invention provides a friction engagement element that inputs a driving force to an automatic transmission mechanism in a state where it cannot be determined whether or not the friction engagement element that inputs a driving force to an automatic transmission mechanism such as a lockup clutch is normal. An object of the present invention is to provide a structure in which the output of the starting rotating electrical machine is not transmitted to the wheels even when the internal combustion engine is started by a starting rotating electrical machine such as a starter motor while being engaged.

The present invention (see, for example, FIGS. 1, 2, and 4) is arranged between an internal combustion engine (2) started by a starting rotating electrical machine (3A) and an automatic transmission mechanism (5) capable of shifting the rotation of the internal combustion engine. Generated by the electric hydraulic pressure generator (32) when the internal friction engine (2) is stopped, and is disposed in the automatic transmission mechanism (5). Engagement / disengagement state of the second friction engagement element (C-1) engaged based on hydraulic pressure and transmitting the power input to the automatic transmission mechanism (5) to the wheels (80fl, 80fr) at the time of engagement. In the control device (19) for the automatic transmission for a hybrid vehicle for controlling
Determination means (42) for determining that the first friction engagement element (7) is normal;
When the internal combustion engine is stopped and the determination means (42) does not determine that the first friction engagement element (7) is normal, the first friction engagement element (7) ) Is engaged, the engagement pressure of the second friction engagement element (C-1) is made to slide by the starting torque of the starting rotating electrical machine (3A) when the internal combustion engine is started. Control means (43) for controlling to the first engagement pressure ,
The determination means (42) outputs the output of the internal combustion engine (2) after the internal combustion engine (2) is started in a state where it is not determined that the first friction engagement element (7) is normal. It is determined whether or not the first friction engagement element (7) is normal by detecting a difference in rotational speed between the shaft (8) and the input shaft (10) of the automatic transmission mechanism (5). Perform post-start judgment
The control means (43) determines the second friction engagement element (C−) when the determination means (42) determines that the first friction engagement element (7) is not normal in the determination after starting. 1) is released, and when the determination means (42) determines that the first friction engagement element (7) is normal in the determination after starting, the second friction engagement element (C-1) ) Is controlled to a second engagement pressure larger than the first engagement pressure .

  Further, according to the present invention (see, for example, FIGS. 1, 2, and 4), the determination means (42) is configured so that the internal combustion engine (2) is stopped before the internal combustion engine (2) is stopped. It is characterized in that it is determined that the first friction engagement element (7) is normal by detecting a difference in rotational speed with respect to the input shaft (10) of the automatic transmission mechanism (5).

Further, the present invention (see, for example, FIGS. 1, 2, and 4) includes an accelerator detection means (45) for detecting an accelerator opening signal,
The control means (43) determines that the first friction engagement element (7) is normal when the determination means (42) is normal when the accelerator detection means (45) detects an ON signal. Even if not, the engagement pressure of the second friction engagement element (C-1) is controlled to be a third engagement pressure larger than the first engagement pressure.

  In addition, although the code | symbol in the said parenthesis is for contrast with drawing, this is for convenience for making an understanding of invention easy, and has no influence on the structure of a claim. It is not a thing.

According to the first aspect of the present invention, when the determination means does not determine that the first friction engagement element is normal, the control means increases the engagement pressure of the second friction engagement element to start rotation. In order to control the first engagement pressure to be slid by the starting torque of the electric machine, the first friction engagement element remains engaged in a state where it cannot be determined whether or not the first friction engagement element is normal. Even if it is attempted to start the internal combustion engine with the starting rotating electrical machine, the output of the starting rotating electrical machine is not transmitted to the wheels, and it is possible to prevent the driver from feeling uncomfortable. Further, after the internal combustion engine is started, the determination means determines whether or not the first friction engagement element is normal. If not normal, the engagement pressure of the second friction engagement element is reduced. The load on the internal combustion engine can be reduced, and if normal, the engagement pressure of the second friction engagement element can be increased to smoothly switch to running on the internal combustion engine.

  According to the second aspect of the present invention, since the determination by the determining means is performed before the internal combustion engine is stopped, there is no decrease in the torque and the rotational speed of the internal combustion engine due to the stop of the internal combustion engine. It is possible to determine that the first friction engagement element is normal by detecting the difference in the rotational speed from the input shaft of the speed change mechanism.

According to the third aspect of the present invention, when the driver intends to drive the vehicle, the engagement pressure of the second friction engagement element is increased regardless of the determination by the determination means, and the internal combustion engine is used. It can be made to run.

Schematic which shows the hybrid vehicle which can apply the control apparatus of the automatic transmission which concerns on embodiment of this invention. The skeleton figure which shows the automatic transmission of this embodiment. The engagement table of the automatic transmission of this embodiment. The block diagram which shows the control apparatus of the automatic transmission of this embodiment. In this embodiment, the state of vehicle speed, engine rotation, input rotation, and clutch pressure when it is known in advance whether or not the lockup clutch is normal is shown. B) is a time chart when normal. The time chart which shows the state of engine rotation, input rotation, and a clutch pressure when an engine restarts with the clutch C-1 being engaged in the state where a lockup clutch is not normal. In this embodiment, when it is not determined that the lock-up clutch is normal, the lock-up clutch indicating the state of the vehicle speed, the engine rotation, the input rotation, and the clutch pressure is when (A) is not normal. , (B) is a time chart when normal. In this embodiment, when it is not determined that the lock-up clutch is normal and the accelerator is turned on, the lock-up clutch indicating the state of the vehicle speed, the engine rotation, the input rotation, and the clutch pressure is (A ) Is a time chart when not normal, and (B) is a time chart when normal. The flowchart which shows an example of control of the control apparatus of the automatic transmission of this embodiment.

  Embodiments according to the present invention will be described below with reference to FIGS. First, an example of a hybrid vehicle to which the automatic transmission of this embodiment can be applied will be described with reference to FIG.

  A hybrid vehicle 100 according to the present embodiment is a rear motor type hybrid vehicle, and an internal combustion engine (E / G) 2 is mounted on the front side, and transmission between the internal combustion engine 2 and the left and right wheels 80fl and 80fr on the front side. A hybrid vehicle automatic transmission (hereinafter simply referred to as “automatic transmission”) 1 is mounted on a path L (see FIG. 2), and is configured as a so-called FF (front engine, front drive) type vehicle. And a rear motor (rotary electric machine) 20 that is drivingly connected to the left and right wheels 80rl and 80rr on the rear side, that is, front wheel drive during engine running, rear wheel drive during EV running, and four during hybrid running. It is configured so that wheel drive is possible.

  Specifically, the internal combustion engine 2 is connected to a belt-type integrated starter generator 3A that is a rotating electric machine for starting, and the internal combustion engine 2 is configured to be startable. The belt-type integrated starter / generator (BISG) 3A can start the internal combustion engine 2 at a high output by being supplied with electric power from a high voltage battery (Hi-V Battery) 24 via an inverter 23. At the same time, the high-voltage battery 24 can be charged while the internal combustion engine 2 is being started (driven).

  One starter (Starter) 3B is a starter that is driven by a general low-voltage battery (Lo-V Battery) 26 (so-called 12V type power supply). In this hybrid vehicle 100, after the rotational speed of the internal combustion engine 2 is increased to a rotational speed higher than the idle rotational speed using a belt-type integrated starter generator (BISG) 3 </ b> A at room temperature (for example, 0 degrees or more), the internal combustion engine 2 is ignited, and at a low temperature (for example, less than 0 degrees), the internal combustion engine 2 is normally started using the starter 3B.

  The internal combustion engine 2 is connected to an automatic transmission 1 described later in detail. The automatic transmission 1 roughly includes a torque converter (T / C) 4, an automatic transmission mechanism (T / M) 5 that can change the rotation of an internal combustion engine 2 described later, a hydraulic control device (V / B) 6, and the like. A torque converter 4 is drivingly connected to the internal combustion engine 2. An automatic transmission mechanism (T / M) 5 is drivingly connected to the torque converter 4, and the automatic transmission mechanism 5 is connected to the left and right axles 81l via a differential device D (see FIG. 2) as will be described in detail later. , 81r and drivingly coupled to the left and right wheels 80fl, 80fr on the front side. A mechanical oil pump is drivably coupled to a pump impeller 4a (see FIG. 2) described later of the torque converter 4.

  The automatic transmission mechanism 5 is provided with a hydraulic control device (V / B) 6 for hydraulically controlling a friction engagement element (clutch or brake) described later. A built-in solenoid valve or the like is electronically controlled based on an electronic command from a control unit (TCU: Transmission Control Unit) 19 which is a transmission control device. Further, as will be described in detail later, the hydraulic control device 6 is provided with an electric oil pump 32 that is an electric hydraulic pressure generator driven independently of the internal combustion engine 2. It is configured to be able to supply hydraulic pressure to the control device 6.

  The electric oil pump 32 and the control unit 19 are driven using the power of the low voltage battery 26. The low voltage battery 26 is connected to a high voltage battery 24 via a DC / DC converter (step-down circuit) 25 and is configured to be supplied with electric power from the high voltage battery 24.

  On the other hand, the rear motor 20 is connected to a high voltage battery 24 via an inverter 23, and is configured to be capable of power running and regeneration. The rear motor 20 is drivingly connected to a gear box (Gear Box) 21 via a motor disconnection clutch CM. The gear box 21 incorporates a reduction gear mechanism with a predetermined reduction ratio (not shown) and a differential device, and when the motor disconnection clutch CM is engaged, the rotation of the rear motor 20 is reduced to the reduction gear of the gear box 21. While decelerating by the mechanism and absorbing the differential rotation of the left and right axles 82l and 82r by the differential device, it is transmitted to the left and right wheels 80rl and 80rr on the rear side.

  Next, the configuration of the automatic transmission 1 will be described with reference to FIG. The automatic transmission 1 is arranged so as to constitute a transmission path L between the internal combustion engine 2 (see FIG. 1) and the left and right wheels 80fl and 80fr on the front side, and the automatic transmission 1 of the internal combustion engine 2 (see FIG. 1). An automatic transmission input shaft 8 that can be connected to the crankshaft is provided, and the torque converter 4 and the automatic transmission mechanism 5 described above are provided around the axial direction of the input shaft 8.

  The torque converter 4 includes a pump impeller 4a connected to the input shaft 8 of the automatic transmission 1, a turbine runner 4b to which rotation of the pump impeller 4a is transmitted via a working fluid, and the turbine runner 4b to the pump impeller 4a. The turbine runner 4b is connected to the input shaft 10 of the automatic transmission mechanism 5 disposed coaxially with the input shaft 8. It is connected. The torque converter 4 is provided with a lock-up clutch 7 that is a first friction engagement element. When the lock-up clutch 7 is engaged, the input shaft 8 of the automatic transmission 1 is The rotation is directly transmitted to the input shaft 10 of the automatic transmission mechanism 5. That is, the lock-up clutch 7 is disposed between the internal combustion engine 2 and the automatic transmission mechanism 5 and directly connects the internal combustion engine 2 and the automatic transmission mechanism 5 in the engaged state.

  The stator 4c is fixed by the one-way clutch F in a state where the rotation of the turbine runner 4b is lower than the rotation of the pump impeller 4a, receives the reaction force of the oil flow, and generates a torque increasing action. When the rotation of the runner 4b is exceeded, the engine runs idle and the oil flow does not act in the negative direction.

  Further, the pump impeller 4 a is driven and connected at its end on the automatic transmission mechanism 5 side to a mechanical oil pump 31 (not shown in FIG. 2), that is, the mechanical oil pump 31 is connected via an input shaft 8. Are connected to the internal combustion engine 2 so as to be linked.

  The automatic transmission mechanism 5 includes a planetary gear SP and a planetary gear unit PU on the input shaft 10. The planetary gear SP is a so-called single pinion planetary gear that includes a sun gear S1, a carrier CR1, and a ring gear R1, and has a pinion P1 that meshes with the sun gear S1 and the ring gear R1.

  The planetary gear unit PU has a sun gear S2, a sun gear S3, a carrier CR2, and a ring gear R2 as four rotating elements. The carrier CR2 has a long pinion PL that meshes with the sun gear S2 and the ring gear R2, and the sun gear S3. This is a so-called Ravigneaux type planetary gear that has meshing short pinions PS that mesh with each other.

  The sun gear S <b> 1 of the planetary gear SP is connected to a boss portion that is integrally fixed to the mission case 9, and the rotation is fixed. The ring gear R1 is in the same rotation as the rotation of the input shaft 10 (hereinafter referred to as “input rotation”). Further, the carrier CR1 is decelerated by decelerating the input rotation by the fixed sun gear S1 and the ring gear R1 that rotates, and the clutch C-1 and the clutch C, which are the second friction engagement elements. -3.

  The sun gear S2 of the planetary gear unit PU is connected to a brake B-1 formed of a band brake so as to be freely fixed to the transmission case, and is connected to the clutch C-3 via the clutch C-3. Thus, the decelerated rotation of the carrier CR1 can be input. The sun gear S3 is connected to the clutch C-1, so that the decelerated rotation of the carrier CR1 can be input.

  Further, the carrier CR2 is connected to a clutch C-2 to which the rotation of the input shaft 10 is input, and the input rotation can be freely input via the clutch C-2, and the one-way clutch F-1 and Connected to the brake B-2, rotation in one direction is restricted with respect to the transmission case via the one-way clutch F-1, and rotation can be fixed via the brake B-2. The ring gear R2 is connected to a counter gear 11. The counter gear 11 is connected to wheels 80fl and 80fr via a counter shaft 15 and a differential device D.

  In the hybrid vehicle 100 configured as described above, when the engine travels using the driving force of the internal combustion engine 2, the motor disconnection clutch CM shown in FIG. 1 is released, and the rear motor 20 has wheels 80rl and 80rr. It is made the state disconnected from. In the automatic transmission 1, the hydraulic control device 6 is electronically controlled by determining the optimum shift stage by the control unit 19 according to the vehicle speed and the accelerator opening, and the first forward speed formed based on the shift determination. The driving force of the internal combustion engine 2 is shifted between the first to sixth forward speeds and the reverse speed, and the driving force of the internal combustion engine 2 is transmitted to the wheels 80fl and 80fr. Note that the first forward speed to the sixth forward speed and the reverse speed of the automatic transmission 1 are the clutches C-1 to C-3, brakes B-1 to B-2, This is achieved by operating the one-way clutch F-1.

  When shifting from the engine running to the hybrid running, the motor disconnection clutch CM shown in FIG. 1 is engaged, and the rear motor 20 is drivingly connected to the wheels 80rl and 80rr. Thereby, in addition to the engine running, the driving force of the rear motor 20 is appropriately assisted or regenerated based on the accelerator opening (the driver's driving force request), that is, the driving force of the internal combustion engine 2 and the driving force of the rear motor 20 The hybrid vehicle 100 is driven using the.

  During acceleration of the engine running by the driving force of the internal combustion engine 2, the motor separating clutch CM is released, and the rear motor 20 is separated from the wheels 80rl and 80rr so as not to become running resistance. Good. Even when the engine is running, it is preferable to improve the fuel efficiency by engaging the motor separating clutch CM and executing the regenerative braking with the rear motor 20 during deceleration.

  In EV traveling, the motor disconnection clutch CM shown in FIG. 1 is engaged, the rear motor 20 is drivingly connected to the wheels 80rl and 80rr, the internal combustion engine 2 is stopped, and the automatic transmission 1 is stopped. The clutches C-2 to C-3 and the brakes B-1 to B-2 are released, and the automatic transmission 1 is allowed to idle. As a result, the driving force of the rear motor 20 is appropriately powered or regenerated based on the accelerator opening (the driver's request for driving force), that is, the hybrid vehicle 100 travels using only the driving force of the rear motor 20.

  During the EV traveling, members (for example, the differential device D, the counter shaft 15, the counter gear 11, the planetary gear unit PU, etc.) that are drivingly connected to the wheels 80fl and 80fr of the automatic transmission mechanism 5 are accompanied. At the same time, the mechanical oil pump is stopped by stopping the internal combustion engine 2. Therefore, when the internal combustion engine is stopped, it is necessary to supply the lubricating oil to the lubricating portion of the automatic transmission mechanism 5 by the electric oil pump 32.

  Further, during EV travel, as a preparation for transition from EV travel to hybrid travel, the clutch C-1 in the automatic transmission mechanism is in an engaged state. Even if the clutch C-1 is engaged during EV traveling, the automatic transmission mechanism 5 is in a towing state and is in a state similar to that during engine braking, and the one-way clutch F-1 idles. It will be controlled by. Thus, the hydraulic pressure for keeping the clutch C-1 in the engaged state needs to be generated by the electric oil pump 32 as well.

  Further, in the present embodiment, in order to detect whether or not the lock-up clutch 7 is normal, the rotational speed of the internal combustion engine 2 (engine rotation) and the rotational speed of the input shaft 10 of the automatic transmission mechanism 5 (input rotation). ) Are detected. For this purpose, an engine speed sensor 40 that detects the speed of the output shaft of the internal combustion engine 2 and an input shaft speed sensor 41 that detects the speed of the input shaft 10 of the automatic transmission mechanism 5 are provided. In the illustrated example, the engine speed sensor 40 is disposed on the input shaft 8 of the automatic transmission 1 that is directly coupled to the output shaft of the internal combustion engine 2, but may be disposed on the output shaft of the internal combustion engine 2. . Further, the input shaft rotation speed sensor 41 may be disposed in a portion that is directly connected to the input shaft 10 and rotates at the same speed. In the illustrated example, in the vicinity of the clutch C-2 in consideration of interference with other members. It is arranged on the outer peripheral side.

  In the case of the present embodiment, as shown in FIG. 4, the control unit 19, which is a control device for the automatic transmission, locks the clutch based on the signals from the engine speed sensor 40 and the input shaft speed sensor 41. 7 has a determination means 42 for determining whether or not 7 is normal. The determination means 42 is detected by the engine speed detected by the engine speed sensor 40 and the input shaft speed sensor 41 in a state in which the lockup control means 44 described later outputs a signal for releasing the engagement of the lockup clutch 7. When the difference between the rotational speed of the input shaft 10 of the automatic transmission mechanism and the automatic transmission mechanism is greater than a predetermined value, it is determined that the lockup clutch 7 is normal. When the difference is less than the predetermined value, the lockup clutch 7 is not normal. judge.

  For example, when the engine torque is input to the input shaft 8 of the automatic transmission 1 when the internal combustion engine 2 is started, if the engagement of the lockup clutch 7 is released, this torque is automatically changed via the torque converter 4. Input to the input shaft 10 of the mechanism 5. At this time, since torque is input via the torque converter 4, a difference in rotational speed occurs between the input shaft 8 of the automatic transmission 1 and the input shaft 10 of the automatic transmission mechanism 5. On the other hand, if the engagement of the lockup clutch 7 is not released, the engine torque is input to the input shaft 10 of the automatic transmission mechanism 5 via the lockup clutch 7. For this reason, there is almost no difference in rotational speed between the input shaft 8 of the automatic transmission 1 and the input shaft 10 of the automatic transmission mechanism 5. Therefore, it can be determined whether or not the lockup clutch 7 is normal from the difference in the rotational speeds.

  The control unit 19 is a control unit that controls the engagement pressure of the clutch C-1 in addition to the determination unit 42, and includes a clutch control unit 43 that controls the engagement / disengagement state of the clutch C-1, a lock-up clutch. 7 includes a lockup control means 44 for controlling the engagement / disengagement state 7 and an accelerator detection means 45 for detecting an accelerator on signal. The control unit 19 includes various control means other than these, and controls the hydraulic control device 6 and the lockup clutch 7.

The hydraulic control device 6 includes a plurality of linear solenoid valves for controlling the engagement pressure supplied to the hydraulic servos of the clutches C-1 to C-3 and the brakes B-1 to B-2. In particular, the hydraulic pressure control device 6 includes a linear solenoid valve SLC1 that can freely regulate the engagement pressure P _C1 supplied to the hydraulic servo 46 of the clutch C-1, for example, with the line pressure P _L as a source pressure, and a lock A linear solenoid valve SLU capable of adjusting and outputting the engagement pressure P _L-UP of the up clutch 7 (internal pressure of the torque converter 4), for example, with the secondary pressure P _SEC as a source pressure is provided. The linear solenoid valve SLC1 can be controlled by the clutch control means 43, and the linear solenoid valve SLU can be controlled by the lockup control means 44.

  The clutch control means 43 controls the linear solenoid valve SLC1 so that the clutch C-1 is engaged / disengaged based on a shift control map, a driver's shift operation, and the like. Further, as described above, during EV traveling, the linear solenoid valve SLC1 is controlled so that the clutch C-1 is engaged as preparation for transition from EV traveling to hybrid traveling. Further, as will be described later, the engagement pressure of the clutch C-1 is controlled in accordance with the determination by the determination means 42, or in the case where the determination is not made, and further in accordance with each detection result of the accelerator detection means 45. The linear solenoid valve SLC1 is controlled as described above.

  The lockup control means 44 controls the linear solenoid valve SLU so that the lockup clutch 7 is engaged and disengaged based on a lockup control map or the like. During EV travel, the lockup clutch 7 is normally disengaged.

  The accelerator detection means 45 detects a signal of an accelerator sensor 47 that detects on / off of the accelerator (and further, the accelerator opening). In other words, the accelerator detection means 45 detects the driver's intention to drive the vehicle.

  Here, even if the lockup control means 44 issues a signal for releasing the lockup clutch 7 due to, for example, an abnormality of the linear solenoid valve SLU, the engagement of the lockup clutch 7 is not released, that is, the locked state. An unhealthy (abnormal) condition may remain that remains. When the vehicle is running in EV in this state, there is no engine torque, so the engine speed sufficient to determine whether the lockup clutch 7 is normal and the rotation of the input shaft 10 of the automatic transmission mechanism are sufficient. Since there is no difference from the number, it is impossible to determine whether or not the lockup clutch 7 is normal as described above. Further, when the vehicle is traveling on EV, as described above, the clutch C-1 is in an engaged state.

  As described above, it is assumed that the vehicle stops in the EV traveling state without determining whether the lock-up clutch 7 is normal, and the lock-up clutch 7 is abnormal. In this case, since the engine is stopped and there is no hydraulic pressure from the mechanical oil pump 31, and the hydraulic pressure from the electric oil pump 32 cannot keep the lockup clutch 7 on, the lockup clutch is disengaged. Has been. In this state, if the clutch C-1 remains engaged, the battery charge amount decreases, and when the internal combustion engine 2 is started by the belt type integrated starter generator (BISG) 3A, the start is started. At this time, the mechanical oil pump 31 is driven to generate hydraulic pressure, whereby the lockup clutch 7 is engaged (locked), and the starting torque of the BISG 3A is transferred to the wheels via the lockup clutch 7 and the clutch C-1. Will be transmitted. In particular, since the starting torque of the BISG 3A is large, the starting torque that the vehicle is about to start is transmitted to the driver even though the vehicle is stopped by stepping on the brake, which may cause a sense of incongruity.

  Therefore, in the present embodiment, the control unit 19 controls the engagement pressure of the clutch C-1 as follows. That is, when the determination means 42 does not determine that the lockup clutch 7 is normal, the clutch C-1 is slipped by at least the starting torque of the BISG 3A while the lockup clutch 7 is engaged. The control means 43 controls the engagement pressure of the clutch C-1 to the first engagement pressure.

  Specifically, the engagement pressure of the clutch C-1 is made lower than the pressure (usually the line pressure) controlled as preparation for transition from EV traveling to hybrid traveling, and the lockup clutch 7 is engaged. Then, the clutch C-1 is made to slide by the starting torque of the BISG 3A. Although the starter 3B may start the engine, the starter torque of the starter 3B is smaller than the starter torque of the BISG 3A. Therefore, even if it is transmitted by the clutch C-1, there is little discomfort given to the driver. Of course, the first engagement pressure may be controlled to slide with the starting torque of the starter 3B.

  However, the first engagement pressure is preferably controlled so that the clutch C-1 transmits the creep torque after the engine is started. The creep torque is torque that is input to the automatic transmission mechanism 5 after the idling torque of the internal combustion engine 2 is amplified by the torque converter 4 while the lockup clutch 7 is released. That is, the first engagement pressure maintains the idling torque (creep torque) of the internal combustion engine 2 transmitted through the torque converter 4 when the lock-up clutch 7 is normal when the vehicle is stopped. The starter 3B or the BISG 3A starting torque transmitted when the lockup clutch 7 is locked is controlled to slide.

  In the present embodiment, the first engagement pressure is controlled so that the engine maximum creep torque can be maintained. For example, the idling speed of the internal combustion engine 2 may increase when the temperature is cold, and the creep torque may be larger than usual. For this reason, as the first engagement pressure, the creep torque (engine maximum creep torque) when the idling rotational speed of the internal combustion engine 2 becomes maximum can be held.

  Next, the determination means 42 performs a post-start determination that determines whether or not the lockup clutch 7 is normal after the internal combustion engine 2 is started in a state where it is not determined that the lockup clutch 7 is normal. To do. That is, after the internal combustion engine 2 is started, determination by the determination means 42 is possible based on the detection results of the engine speed sensor 40 and the input shaft speed sensor 41. When the determination means 42 determines that the lockup clutch 7 is not normal in the determination after starting, the clutch control means 43 releases the clutch C-1. This prevents the engine output from being transmitted to the wheels even when the lockup clutch 7 remains locked due to an abnormality.

  On the other hand, when the determination unit 42 determines that the lockup clutch 7 is normal in the post-startup determination, the clutch control unit 43 sets the engagement pressure of the clutch C-1 to the first engagement described above. The second engagement pressure is controlled to be larger than the pressure. Specifically, the pressure is returned to the pressure controlled as preparation for transition from EV traveling to hybrid traveling. In this case, since the lock-up clutch 7 is disengaged, the engine output is transmitted to the wheels via the torque converter 4 even when the clutch C-1 is engaged. When the person runs the vehicle, the hybrid running can be performed smoothly.

  On the other hand, when the accelerator detecting unit 45 detects that the accelerator is on, that is, the driver is about to start the vehicle, the clutch control unit 43 determines that the determination unit 42 determines that the lockup clutch 7 is normal. Even if it is not determined, the engagement pressure of the clutch C-1 is controlled to the third engagement pressure that is higher than the first engagement pressure described above. The third engagement pressure is the same as the second engagement pressure described above. However, considering that the lock-up clutch 7 remains locked, the pressure is lower than the second engagement pressure so as to reduce the shock at the start when the lock-up clutch 7 is locked. Anyway.

  Such control according to the present embodiment will be described more specifically with reference to FIGS. 5 to 8, the horizontal axis is the time axis, the vehicle speed is the vehicle speed (solid line), the clutch pressure is the engagement pressure of the clutch C-1 (broken line), and the engine speed is the rotational speed of the internal combustion engine 2 (one point). The chain rotation) and the input rotation are the rotation speed (two-dot chain line) of the input shaft 10 of the automatic transmission mechanism 5.

  First, in the present embodiment, the determination unit 42 determines whether or not the lockup clutch 7 is normal before the internal combustion engine 2 stops. Then, as shown in FIG. 5, when the determination means 42 can determine whether or not the lockup clutch 7 is normal before the internal combustion engine 2 stops, the determination result that the lockup clutch 7 is abnormal. Then, as shown in FIG. 5A, the clutch C-1 is released immediately before the vehicle stops. Thereby, even if the internal combustion engine 2 is restarted thereafter, the engine output is prevented from being transmitted to the wheels.

  On the other hand, if the determination result indicates that the lock-up clutch 7 is normal, as shown in FIG. 5B, preparation for transition from EV traveling to hybrid traveling is performed while maintaining the engagement pressure of the clutch C-1. The pressure is controlled as follows.

  On the other hand, if the determination means 42 cannot determine whether the lock-up clutch 7 is normal before the internal combustion engine 2 stops, if the engagement pressure of the clutch C-1 is maintained, As shown in FIG. 6, the engine rotation increases due to the engine restart, and the starting torque that the vehicle is about to start is transmitted even though the vehicle is stopped by stepping on the brake. There is.

  Therefore, in this embodiment, as shown in FIG. 7, when the determination means 42 cannot determine whether or not the lockup clutch 7 is normal, the engagement pressure of the clutch C-1 is set to the first level described above. Control to engagement pressure. Thereby, even if the lock-up clutch 7 is abnormal, as shown in FIG. 7A, it is possible to prevent the clutch C-1 from slipping due to the engine restart and causing a sense of incongruity due to the starting torque of the BISG 3A. Then, when the internal combustion engine 2 is started and the determination by the determination means 42 becomes possible, the determination after the start by the determination means 42 is performed again, it is determined that the lockup clutch 7 is abnormal, and the clutch C-1 is turned on. release.

  On the other hand, when the lock-up clutch 7 is normal, as shown in FIG. 7B, the lock-up clutch 7 is released even when the engine is restarted. Regardless, no torque is suddenly transmitted to the wheels. However, in this state, creep torque is input to the automatic transmission mechanism 5 via the torque converter 4. Since the first engagement pressure maintains the creep torque as described above, if the driver releases the brake, the vehicle tries to start with the creep torque. Since the brake is applied in FIG. 7B, the vehicle speed is zero.

  Then, when the internal combustion engine 2 is started and the determination by the determination means 42 is possible, the determination after the start by the determination means 42 is performed again, it is determined that the lockup clutch 7 is normal, and the clutch C-1 The engagement pressure is controlled to a second engagement pressure that is controlled as preparation for transition from EV traveling to hybrid traveling. That is, the normal engagement pressure is restored.

  Further, even if the determination means 42 cannot determine whether or not the lock-up clutch 7 is normal, if the driver intends to start, as shown in FIG. Is once lowered to the first engagement pressure and then raised again to the third engagement pressure by detecting the accelerator on signal. As a result, when the lock-up clutch 7 is abnormal, as shown in FIG. 8A, the clutch C-1 slips when the engine starts, but when the accelerator is turned on, the clutch C-1 The engagement pressure rises and the vehicle moves forward. Further, when the lock-up clutch 7 is normal, as shown in FIG. 8 (B), when the engine is started, the engagement pressure of the clutch C-1 is low, but the clutch is turned on when the accelerator is turned on. The engagement pressure of C-1 rises and the vehicle moves forward.

  One example of the control of this embodiment will be described with reference to FIG. 4 and FIG. When the control is started, the determination means 42 determines whether or not the lockup clutch 7 is normal when the internal combustion engine 2 is operated. If it is abnormal (S1), the clutch C-1 is released in a fail-safe manner. (S2). Next, if it is determined that the determination means 42 is not abnormal but normal (S3), the control for reducing the engagement of the clutch C-1 to the first engagement pressure during EV traveling is not performed (S4).

  On the other hand, when the determination unit 42 cannot determine abnormality in S1 and cannot determine normality in S3, the control unit 19 first determines the internal combustion engine from the signal of the engine speed sensor 40, for example. 2 is stopped (S5), and if it is stopped, it is determined from the vehicle speed sensor 48 (FIG. 4) whether the vehicle speed is zero, that is, whether the vehicle is stopped (S6). If the vehicle is stopped, the control unit 19 detects the accelerator off by the accelerator detecting unit 45 (S7), and if the vehicle is off, the clutch control unit 34 determines the engagement pressure of the clutch C-1. The engagement pressure is controlled to 1 (S8).

  Next, when the internal combustion engine 2 is restarted (S9), the control unit 19 detects the accelerator on by the accelerator detecting means 45 (S10), and the clutch control means 34 sets the engagement pressure of the clutch C-1 to the first. The normal engagement pressure (second engagement pressure) is returned from the engagement pressure (S11). On the other hand, if the determination means 42 determines that the lockup clutch 7 is normal after the engine is started in the accelerator off state (S12), the clutch control means 34 sets the engagement pressure of the clutch C-1 to the first engagement. The pressure is returned to the normal engagement pressure (second engagement pressure) (S11).

  On the other hand, if the determination means 42 determines that the lockup clutch 7 is abnormal after the engine is started in the accelerator-off state (S13), the clutch C-1 is released in a fail-safe manner (S14). On the other hand, if it is not possible to determine that it is normal in S12 and it is not possible to determine that it is abnormal in S13, the process returns to S10, and the engagement pressure of the clutch C-1 is kept at the first engagement pressure. , S10 and subsequent steps are executed.

  In the case of this embodiment configured as described above, even if it is not possible to determine whether or not the lock-up clutch 7 is normal, the first slipping of the engagement pressure of the clutch C-1 with the starting torque of the BISG 3A In order to control the engagement pressure, even if the internal combustion engine 2 is started with the BISG 3A while the lock-up clutch 7 is engaged, the output of the BISG 3A is not transmitted to the wheels, and it is possible to prevent the driver from feeling uncomfortable. On the other hand, since the creep torque is transmitted as the first engagement pressure, the creep torque can be transmitted to the wheel when the lockup clutch 7 is normal.

  In the present embodiment, since the determination by the determination means 42 is performed before the internal combustion engine 2 is stopped, by detecting the difference in the rotational speed between the output shaft of the internal combustion engine 2 and the input shaft of the automatic transmission mechanism 5, It can be determined that the lockup clutch 7 is normal.

  Further, after the internal combustion engine 2 is started, the determination means 42 determines whether or not the lockup clutch 7 is normal. If it is not normal (if it is abnormal), the engagement pressure of the clutch C-1 is reduced. Thus, the load on the internal combustion engine 2 can be reduced, and if normal, the engagement pressure of the clutch C-1 can be increased to smoothly switch from EV travel to travel on the internal combustion engine 2. .

  Further, when the driver intends to drive the vehicle, that is, when the accelerator detecting means 45 detects that the accelerator is on, the engagement pressure of the clutch C-1 is increased regardless of the determination by the determining means 42. The traveling by the internal combustion engine 2 can be performed. In other words, even if the engine torque is suddenly transmitted to the wheels via the clutch C-1 while the lockup clutch 7 remains locked, if the driver intends to drive the vehicle, the driver does not feel so uncomfortable. . In addition, even when the driver intends to drive the vehicle, if the engagement pressure of the clutch C-1 is reduced, for example, the repair shop of the lockup clutch 7 cannot be self-propelled for repair. Therefore, in this embodiment, even if the lock-up clutch 7 is abnormal, if the driver intends to drive the vehicle, the control for reducing the engagement pressure of the clutch C-1 is not executed.

  In the above-described embodiment, the case where the present invention is applied to the hybrid vehicle in which the front wheels are driven by the internal combustion engine 2 and the rear wheels are driven by the rear motor 20 has been described. However, the clutch that engages and disengages the engine, the motor, and the automatic transmission mechanism. The present invention can also be applied to a structure that switches between EV traveling and hybrid traveling by engaging and disengaging the clutch. In this case, this clutch becomes the first friction engagement element.

  In the present embodiment, the automatic transmission 1 is a multi-stage automatic transmission that achieves the sixth forward speed and the reverse speed. However, the present invention is not limited to this. For example, the seventh forward speed or the fifth forward speed is used. The present invention can also be applied to a multi-stage transmission having a number of stages or less, or a continuously variable transmission that performs a continuously variable transmission of a belt type, a toroidal type or a ring cone type.

  In the present embodiment, the clutch C-1 in the automatic transmission mechanism 5 is engaged during EV traveling, that is, the second friction engagement element is the clutch C-1. Depending on the vehicle model, the second friction engagement element may be another clutch or brake in the automatic transmission mechanism 5. For example, at the time of reverse driving the vehicle backward, the second friction engagement element is the clutch C-3, and the engagement pressure of the clutch C-3 is controlled in the same manner as the clutch C-1.

DESCRIPTION OF SYMBOLS 1 Automatic transmission for hybrid vehicles 2 Internal combustion engine 3A Belt type integrated starter generator (BISG, starting rotating electrical machine)
3B Starter (starting rotating electrical machine)
4 Torque converter 5 Automatic transmission mechanism 7 Lock-up clutch (first friction engagement element)
19 Control unit (automatic transmission control device)
20 Rear motor (rotary electric machine)
32 Electric oil pump (electric oil pressure generator)
40 engine speed sensor 41 input shaft speed sensor 42 determination means 43 clutch control means (control means)
44 Lock-up control means 45 Accelerator detecting means 47 Accelerator sensor 80fl, 80fr Wheel 100 Vehicle C-1 Clutch (second friction engagement element)

Claims (3)

An engagement / disengagement state of a first friction engagement element disposed between an internal combustion engine started by a starting rotating electrical machine and an automatic transmission mechanism capable of shifting the rotation of the internal combustion engine, and disposed in the automatic transmission mechanism. And engaging / disengaging a second friction engagement element that is engaged based on the hydraulic pressure generated by the electric hydraulic pressure generator when the internal combustion engine is stopped, and that transmits the power input to the automatic transmission mechanism to the wheel when engaged. In a control device for an automatic transmission for a hybrid vehicle that controls the state,
Determining means for determining that the first friction engagement element is normal;
When the internal combustion engine is stopped and the determination means does not determine that the first friction engagement element is normal, the first friction engagement element is engaged with the first friction engagement element. Control means for controlling the engagement pressure of the second friction engagement element to the first engagement pressure so as to slide by the starting torque of the starting rotating electrical machine when starting the internal combustion engine ,
The determination means rotates the output shaft of the internal combustion engine and the input shaft of the automatic transmission mechanism after the internal combustion engine is started in a state where it is not determined that the first friction engagement element is normal. Performing a post-startup determination to determine whether the first friction engagement element is normal by detecting a difference in number;
The control means releases the second friction engagement element when the determination means determines that the first friction engagement element is not normal in the determination after start-up, and the determination means determines the determination after the start-up. When it is determined that the first friction engagement element is normal, the engagement pressure of the second friction engagement element is controlled to be a second engagement pressure that is larger than the first engagement pressure. ,
A control device for an automatic transmission for a hybrid vehicle. The determination means detects the difference in rotational speed between the output shaft of the internal combustion engine and the input shaft of the automatic transmission mechanism before the internal combustion engine stops, so that the first friction engagement element is normal. Is determined,
The control device for an automatic transmission for a hybrid vehicle according to claim 1, characterized in that: Accelerator detecting means for detecting the accelerator opening signal,
When the accelerator detecting means detects an ON signal, the control means does not determine that the first friction engagement element is normal, but the second friction engagement is not detected. Controlling the engagement pressure of the element to a third engagement pressure larger than the first engagement pressure;
The control apparatus for an automatic transmission for a hybrid vehicle according to claim 1 or 2, wherein

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