JP2013028231A - Hybrid vehicle and method of controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compulsorily release a state where rotation of an electric motor is locked by the external force in the hybrid vehicle that includes a plurality of clutch type transmissions.SOLUTION: The gear position is changed from the gear position of a first transmission engaged when the electric motor is in a locked state to the gear position of a second transmission by releasing the gear position of the first transmission while engaging either one of the second transmission. The electric motor that exists mechanically in the locked state is rotated by changing the engaging state of at least either of a first clutch or a second clutch together with the change in the gear position. If the electric motor that exists in the locked state can be rotated, the occurrence of trouble by the heat of the switching element by the common mode energization can be prevented, since the current flow path can be switched from one certain switching element in the electric motor in which the energization current has continued to flow in the locked state to the other switching elements where the current does not flow.

Description

  The present invention relates to a vehicle (so-called hybrid vehicle) including an internal combustion engine and a motor as a drive source and a control method thereof, and particularly, in a hybrid vehicle including a multi-clutch transmission, the rotation of the motor is locked by an external force. The present invention relates to a control technique for forcibly releasing a state.

  Recently, a hybrid type vehicle further including an electric motor (motor) in addition to an internal combustion engine (engine) as a drive source is known. Hybrid vehicles generally drive DC motors by converting DC power from a DC power source (battery) into AC power using a power converter (typically an inverter). The vehicle can be driven by any one of a single traveling, a motor independent traveling that travels the vehicle with only an electric motor, and a hybrid traveling that travels the vehicle by combining an engine and an electric motor.

  In such a hybrid vehicle, when the motor runs alone, the vehicle stops when the vehicle does not move back and forth while standing still on the slope, or when the driver depresses the accelerator pedal and the brake pedal at the same time (so-called both steps). In some cases, the rotation of the electric motor is locked by an external force (also called a stall). In such a motor lock state, since a phenomenon called in-phase energization in which current concentrates on only one phase winding among a plurality of phase stator windings provided in the electric motor occurs, the motor lock state in particular. When a long period of time occurs, a switching element corresponding to the phase where the current is concentrated among a plurality of switching elements provided in the power converter (inverter) generates heat, and its temperature rises beyond an allowable range. As a result, the switching element may be damaged by heat.

  Thus, as a conventional technique for dealing with the above problem, for example, there is a driving force control apparatus described in Patent Document 1. In the device of this Patent Document 1, the switching force corresponding to a specific phase is switched by reducing or disconnecting the fastening force of the clutch that transmits the driving force of the traveling motor to the driving wheel and switching the energized phase of the traveling motor. The temperature is prevented from rising beyond an allowable range. Specifically, when the rotation speed of the traveling motor is equal to or lower than a predetermined value, if energization to the stator winding of any phase of the traveling motor continues for a predetermined time, the driving force of the traveling motor is changed to the driving wheel. The fastening force of the clutch transmitted to is temporarily reduced or disconnected.

Patent No. 3964446

  By the way, in recent years, a transmission for a vehicle (transmission) has an input shaft (hereinafter, referred to as an “input shaft”) of a first transmission mechanism configured with an odd number of shift stages in order to eliminate interruption of transmission of mechanical power at the time of shift. A first clutch capable of engaging an internal combustion engine output shaft (hereinafter referred to as an engine output shaft or an engine output shaft) and a second speed change mechanism comprising an even number of speed stages. A so-called dual clutch transmission that includes a second clutch capable of engaging an engine output shaft (hereinafter referred to as a second input shaft) and an engine output shaft, and that performs shifting by alternately switching the two clutches. It has been known. In this dual clutch transmission, for example, when shifting from an odd number to an even number, an even number of gear pairs are meshed in advance, and the first clutch that transmits mechanical power to the odd number is brought into a released state. At the same time, the second clutch that transmits the mechanical power to the even-numbered stages is set to the engaged state, thereby suppressing the interruption of the power transmission at the time of shifting.

  However, the conventional device shown in Patent Document 1 cannot be applied to a hybrid vehicle of the type including the above-described dual clutch transmission. This is because, in a hybrid vehicle including a dual clutch transmission, an input shaft that transmits power from the engine and an input shaft that transmits power from the electric motor are arranged coaxially. However, the device described in Patent Document 1 is applied to a vehicle in which the shaft for transmitting power from the engine and the shaft for transmitting power from the electric motor are not arranged coaxially. It was impossible to apply to a hybrid vehicle having a dual clutch transmission in which an input shaft for transmitting power and an input shaft for transmitting power from an electric motor are arranged coaxially.

  The present invention has been made in view of the above points, and in a hybrid vehicle having a dual clutch transmission, when the rotation of an electric motor is locked by an external force, the motor is kept in a state where driving wheels are stopped. It is an object of the present invention to provide a hybrid vehicle that can be temporarily released from a locked state and a control method thereof.

  The hybrid vehicle according to the present invention has an internal combustion engine (2) and an electric motor (3) as a drive source, and mechanical power from the internal combustion engine output shaft and the electric motor (3) is supplied to the electric motor (3). The first input shaft (100) connected to the first input shaft (100) is engaged, and any one of a plurality of shift stages is engaged to engage the first input shaft (100) and the drive wheels (7R, 7L). And a second input shaft (400) that receives mechanical power from the output shaft of the internal combustion engine, and engages any one of a plurality of shift speeds to the second input. The second transmission mechanism capable of engaging the shaft (400) and the drive wheels (7R, 7L), and the engagement and disengagement between the output shaft of the internal combustion engine and the first input shaft (100). Relationship between the switchable first connecting / disconnecting means (C1), the internal combustion engine output shaft and the second input shaft (400). And a second connection / disconnection means (C2) capable of switching between non-engagement, an engagement state of gear stages in the first transmission mechanism and the second transmission mechanism, and the first connection / disconnection means (C1) and the second connection / disconnection. In a hybrid vehicle including a control device (10) capable of controlling the engagement state of the contact means (C2), the control device (10) detects a lock state of the electric motor (3). S1), and when detecting the locked state by the lock detecting means (S1), while engaging one of the gears of the second transmission mechanism, releasing the gear of the first transmission mechanism, And a lock state releasing means (S2) for changing an engagement state of at least one of the first connecting / disconnecting means (C1) and the second connecting / disconnecting means (C2).

As a preferred embodiment of the present invention, the lock state releasing means (S2) determines the engagement state of the first connecting / disconnecting means (C1) with the output shaft of the internal combustion engine and the first input shaft (100). The engaged state of the second connecting / disconnecting means (C2) is changed to the engaged state in which the engine output shaft and the second input shaft (400) are engaged.
Furthermore, the locked state releasing means (S2) further reduces the fastening force of at least one of the first connecting / disconnecting means (C1) and the second connecting / disconnecting means (C2) in the engaged state.

  In the hybrid vehicle including the dual clutch transmission according to the present invention, by engaging any one shift stage of the second transmission mechanism while disengaging the shift stage of the first transmission mechanism, the electric motor ( 3) The gear position is changed from the gear position of the first transmission mechanism that was engaged when the gear is in the locked state to the gear position of the second transmission mechanism. In addition, by changing the engagement state of at least one of the first connecting / disconnecting means (C1) or the second connecting / disconnecting means (C2) along with the change of the gear position, the electric motor (mechanically locked) ( Rotate 3). If the motor (3) in the locked state can be rotated, the current flows from one switching element in the motor in which the energization current has continued to flow in the locked state to any one of the other switching elements in which no current flows. Therefore, the occurrence of a failure due to the heat of the switching element can be prevented. In particular, the engagement state of the first connection / disconnection means (C1) and the second connection / disconnection means (C2) is set to the fastening state, and further, the first connection / disconnection means (C1) and the second connection / disconnection in the fastening state are performed. By controlling such that the fastening force of at least one of the contact means (C2) is reduced, the electric motor (3) can be mechanically rotated. By rotating the electric motor (3) by such a mechanical operation, it takes very little time for torque to be released by the external force input from the drive wheels, and it is not necessary to start the internal combustion engine (2). This is advantageous because it does not waste fuel.

  Note that the reference numerals in the parentheses described above exemplify the corresponding constituent elements in the embodiments described later for reference.

  According to the present invention, when the locked state is detected, at least one of the engagement / disengagement control of the shift speed in the first transmission mechanism and the second transmission mechanism, and the first connection / disconnection device and the second connection / disconnection device. The electric motor in the locked state is rotated by a mechanical operation in the transmission caused by performing engagement control of both clutches that change the engagement state of the clutch. If the electric motor in the locked state can be rotated, in-phase energization can be avoided. In the present invention in which the electric motor is rotated by a mechanical operation in accordance with the control described above, the time for the torque to be released due to the external force input from the drive wheels is very small, and it is unnecessary to start the internal combustion engine. There is an effect that fuel is not consumed.

The schematic connection block diagram of the vehicle in one Embodiment of this invention. The circuit diagram which shows the motor and motor control means which are shown in FIG. The skeleton figure of the transmission shown in FIG. The flowchart which shows the outline of the motor lock state release control process performed by the electronic control unit shown in FIG. The flowchart which shows an example of the motor lock state detection process in FIG. The flowchart which shows an example of the motor lock state release process in FIG.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  First, the configuration of the vehicle in the present embodiment will be described. FIG. 1 is a schematic connection configuration diagram of a vehicle according to an embodiment of the present invention. The vehicle 1 of this embodiment is what is called a hybrid vehicle, and as shown in FIG. 1, the engine 2 and the electric motor 3 as a drive source, the electric motor control means 20 for controlling the electric motor 3, the battery 30, and transmission (Transmission) 4, a differential mechanism 5, left and right drive shafts 6R and 6L, and left and right drive wheels 7R and 7L. Here, the electric motor 3 is a motor and includes a motor generator, and the battery 30 is a capacitor and includes a capacitor. The internal combustion engine 2 is an engine and includes a diesel engine and a turbo engine. The rotational driving force of the internal combustion engine (hereinafter referred to as the engine) 2 and the electric motor (hereinafter referred to as the motor) 3 is transmitted to the left and right drive wheels 7R and 7L via the transmission 4, the differential mechanism 5 and the drive shafts 6R and 6L.

  The vehicle 1 also includes an electronic control unit (ECU) 10 for controlling the engine 2, the motor 3, the transmission 4, the differential mechanism 5, the electric motor (hereinafter referred to as motor) control means 20, and the battery 30, respectively. Prepare. The electronic control unit 10 is not only configured as one unit, but also controls, for example, an engine ECU for controlling the internal combustion engine 2, a motor generator ECU for controlling the motor 3 and the motor control means 20, and the battery 30. The battery ECU may be composed of a plurality of ECUs such as an AT ECU for controlling the transmission 4. The electronic control unit 10 shown in this embodiment controls the engine 2 and also controls the motor 3, the battery 30, and the transmission 4.

  The electronic control unit 10 performs control so that the motor alone travels (EV travel) using only the motor 3 as a power source according to various operating conditions, or performs the engine alone travel using only the engine 2 as a power source. Control is performed so as to perform cooperative traveling (HEV traveling) in which both the engine 2 and the motor 3 are used as power sources. In addition, the electronic control unit 10 performs a release control in a motor lock state (described later) (see FIG. 4) and other controls necessary for various operations according to various known control parameters. In this embodiment, as control parameters, for example, the accelerator pedal opening from the accelerator pedal sensor A1 that detects the depression amount of the accelerator pedal, the brake pedal opening from the brake pedal sensor A2 that detects the depression amount of the brake pedal, and the gear Switching element according to the shift position from the shift sensor A3 that detects the speed (shift speed), the motor speed from the speed sensor A4 that detects the speed of the motor 3, and each phase of the motor 3 in the motor control means 20 Various signals such as the inverter element temperature from the temperature sensor A5 that detects the temperature of the vehicle and the vehicle inclination angle from the inclination angle sensor A6 that detects the inclination are input. Of course, signals other than those described here may be input.

  The engine 2 is an internal combustion engine that generates driving force for running the vehicle 1 by mixing fuel with air and burning it. The motor 3 functions as a motor that generates a driving force for running the vehicle 1 using the electric energy of the battery 30 when the engine 2 and the motor 3 are collaboratively run or when the EV 3 is driven only by the motor 3. In addition, when the vehicle 1 decelerates, it also functions as a generator that generates electric power by regeneration of the motor 3. During regeneration of the motor 3, the battery 30 is charged with electric power (regenerative energy) generated by the motor 3.

  The motor 3 is connected to the motor control means 20. FIG. 2 is a circuit diagram showing the motor 3 and the motor control means 20 shown in FIG. As shown in FIG. 2, the motor control means 20 is an inverter (power converter) including a U-phase arm 21, a V-phase arm 22, and a W-phase arm 23, and supplies power from a battery 30. Is provided in parallel with the battery power line L for use. Each phase arm of the inverter 20 is composed of switching elements connected in series to the battery power supply line L. For example, the U-phase arm 21 includes switching elements Q11 and Q12, the V-phase arm 22 includes switching elements Q13 and Q14, and the W-phase arm 23 includes switching elements Q15 and Q16. The switching elements Q11 to Q16 are power semiconductor switching elements such as an IGBT (Insulated Gate Bipolar Transistor), a power MOS (Metal Oxide Semiconductor) transistor, or a power bipolar transistor. Anti-parallel diodes D11 to D16 are connected to these switching elements Q11 to Q16, respectively. On / off of the switching elements Q11 to Q16 is controlled by a switching control signal from the electronic control unit 10.

  The motor 3 is a brushless DC motor such as a permanent magnet type three-phase AC motor using a permanent magnet as a field, for example, and includes a U-phase coil winding U1, a V-phase coil winding V1, and a W-phase coil provided on the stator. Winding W1 and a rotor (not shown) are included. One end of U-phase coil winding U1, V-phase coil winding V1 and W-phase coil winding W1 are connected to each other at neutral point N1, and the other ends are connected to U-phase arm 21, V-phase arm 22 of inverter 20, and Each is connected to a W-phase arm 23. The inverter 20 performs bidirectional power conversion between the battery 30 and the motor 3 by on / off control (switching control) of the switching elements Q11 to Q16 in response to the switching control signal from the electronic control unit 10. Specifically, the inverter 20 converts a DC voltage received from the battery 30 via the battery power line 7 into a three-phase AC voltage according to switching control by the electronic control unit 10, and converts the converted three-phase AC voltage to the motor 3. Output to. As a result, the motor 3 is driven to generate a designated torque. The inverter 20 converts the three-phase AC voltage generated by the motor 3 in response to the output of the engine 2 into a DC voltage according to switching control by the electronic control unit 10, and the converted DC voltage is passed through the battery power line 7. It can also be output to the battery 30.

  Next, the configuration of the transmission 4 of the present embodiment will be described. FIG. 3 is a skeleton diagram of the transmission 4 shown in FIG. The transmission 4 shown here is a parallel shaft transmission of 7 forward speeds and 1 reverse speed, and is a dry dual clutch transmission (DCT).

  The transmission 4 includes a crankshaft (not shown) that forms the engine output shaft of the engine 2 and an inner main shaft 100 (first input shaft) that is connected to the motor 3, and an outer that forms the outer cylinder of the inner main shaft 100. A main shaft 101 (second input shaft), a secondary shaft 400 (second input shaft) parallel to the inner main shaft 100, an idle gear 300, a reverse shaft 500, and a counter shaft that is parallel to these shafts and forms an output shaft 200 is provided.

  Among these shafts, the outer main shaft 101 is always engaged with the reverse shaft 500 and the secondary shaft 400 via the idle gear 300, and the counter shaft 200 is further always engaged with the differential mechanism 5 (not shown in FIG. 3). Be placed.

  The transmission 4 also includes a first clutch C1 (first connecting / disconnecting device) for odd-numbered stages and a second clutch C2 (second connecting / disconnecting apparatus) for even-numbered stages. The first and second clutches C1 and C2 are dry clutches. The first clutch C1 is coupled to the inner main shaft 100 (first input shaft). The second clutch C2 is coupled to the outer main shaft 101 (a part of the second input shaft), and the reverse shaft 500 and the secondary shaft 400 (first shaft) from the gear 48 fixed on the outer main shaft 101 via the idle gear 300. 2 part of the input shaft).

  A planetary gear mechanism 70 is fixedly disposed at a predetermined position from the motor 3 of the inner main shaft 100 (first input shaft). The sun gear 71 of the planetary gear mechanism 70 is the rotor of the motor 3 and the carrier 73 is the third-speed drive gear 43. The ring gear 75 is connected to the inner main shaft 100 (first input shaft). On the outer periphery of the inner main shaft 100 (first input shaft), in order from the left side in FIG. 3, a carrier 73 of a planetary gear mechanism 70 serving as a first speed drive gear, a third speed drive gear 43, a seventh speed drive gear 47, A fifth speed drive gear 45 is arranged. The third speed drive gear 43, the seventh speed drive gear 47, and the fifth speed drive gear 45 are rotatable relative to the inner main shaft 100, and the gear 43 is connected to the carrier 73 of the planetary gear mechanism 70 as described above. Has been. Further, on the inner main shaft 100, a 3-7 speed synchromesh mechanism (selector mechanism) 81 is provided between the 3rd speed drive gear 43 and the 7th speed drive gear 47 so as to be slidable in the axial direction. Corresponding to the high-speed drive gear 45, a 5-speed synchromesh mechanism (selector mechanism) 82 is provided to be slidable in the axial direction. The synchromesh mechanism (selector mechanism) corresponding to the desired gear stage is slid to insert the gear stage synchronism, whereby the gear stage is connected to the inner main shaft 100 (first input shaft). These gears and synchromesh mechanisms provided in association with the main shaft 100 (first input shaft) constitute a first transmission mechanism for realizing odd-numbered shift stages. Each drive gear of the first speed change mechanism meshes with a corresponding driven gear provided on the counter shaft 200 to drive the counter shaft 200 to rotate.

  On the outer periphery of the secondary shaft 400 (second input shaft), the second-speed drive gear 42, the sixth-speed drive gear 46, and the fourth-speed drive gear 44 are relatively rotatably disposed in order from the left side in FIG. . Further, on the secondary shaft 400, a 2-6 speed synchromesh mechanism 83 is provided between the 2nd speed drive gear 42 and the 6th speed drive gear 46 so as to be slidable in the axial direction. Correspondingly, a 4-speed synchromesh mechanism (selector mechanism) 84 is provided to be slidable in the axial direction. Also in this case, the gear stage is connected to the secondary shaft 400 (second input shaft) by sliding the synchromesh mechanism (selector mechanism) corresponding to the desired gear stage to insert the synchromesh of the gear stage. These gears and synchromesh mechanisms provided in association with the secondary shaft 400 (second input shaft) constitute a second speed change mechanism for realizing an even number of speeds. Each drive gear of the second speed change mechanism also meshes with a corresponding driven gear provided on the countershaft 200 to drive the countershaft 200 to rotate. The gear 49 fixed to the secondary shaft 400 is coupled to the idle gear 300, and is coupled from the idle gear 300 to the second clutch C2 via the outer main shaft 101.

  In the first speed change mechanism, when an arbitrary speed is selected, the gear corresponding to the speed is synchronized and the gear is connected to the inner main shaft 100 (first input shaft). Means. Further, in the first speed change mechanism, to realize a speed stage (or drive gear stage) for running the engine means that the speed stage (or drive gear stage) is selected as described above (with synchronization). This means that the corresponding first clutch C1 is engaged to connect the inner main shaft 100 (first input shaft) to the engine output shaft.

  Similarly, in the second speed change mechanism, when an arbitrary certain speed is selected, the gear corresponding to the speed is synchronized and the gear is connected to the secondary shaft 400 (second input shaft). Means. Further, in this second speed change mechanism, to realize a speed stage (or drive gear stage) for running the engine means that the speed stage (or drive gear stage) is selected as described above (with synchronization). This means that the corresponding second clutch C2 is engaged to connect the secondary shaft 400 (second input shaft) to the engine output shaft.

  A reverse drive gear 46 is disposed on the outer periphery of the reverse shaft 500 so as to be relatively rotatable. On the reverse shaft 500, a reverse synchromesh mechanism 85 is slidably provided in the axial direction corresponding to the reverse drive gear 46, and a gear 50 that engages with the idle gear 300 is fixed. In reverse running, the synchromesh mechanism 85 is synchronized and the second clutch C2 is engaged, so that the rotation of the second clutch C2 is transmitted to the reverse shaft 500 via the outer main shaft 101 and the idle gear 300. Then, the reverse drive gear 46 is rotated. The reverse drive gear 46 meshes with the gear 56 on the inner main shaft 100, and when the reverse drive gear 46 rotates, the inner main shaft 100 rotates in the direction opposite to that during forward movement. The reverse rotation of the inner main shaft 100 is transmitted to the countershaft 200 via the gear 43 connected to the planetary gear mechanism 70. Further, since the reverse drive gear 46 meshes with the gear 91 on the oil pump drive shaft 90, the reverse drive gear 46 is rotated by engaging the first clutch C1 or by engaging the second clutch C2. The rotation of the outer main shaft 101 is transmitted to the oil pump drive shaft 90 via the reverse drive gear 46, and as a result, the oil pump drive shaft 90 rotates and each part of the first transmission mechanism and the second transmission mechanism. An oil pump OP for supplying hydraulic oil to the engine is driven.

  On the countershaft 200, in order from the left side in FIG. 3, the 2-3 speed driven gear 51, the 6-7 speed driven gear 52, the 4-5 speed driven gear 53, the parking gear 54, and the final drive gear are arranged. 55 is fixedly arranged. The final drive gear 55 meshes with a differential ring gear (not shown) of the differential mechanism 5, whereby the rotation of the output shaft of the countershaft 200 is applied to the input shaft (that is, the vehicle propulsion shaft) of the differential mechanism 5. Communicated.

  A one-way clutch 41 is provided so as to engage with the ring gear 75 and the planetary gears 72 and 74 of the planetary gear mechanism 70.

  When the synchromesh of the 2-6 speed synchromesh mechanism 83 is slid leftward, the 2nd speed drive gear 42 is coupled to the secondary shaft 400, and when slid rightward, the 6th speed drive gear 46 is coupled to the secondary shaft 400. . When the synchromesh of the 4-speed synchromesh mechanism 84 is slid rightward, the 4-speed drive gear 44 is coupled to the secondary shaft 400. By engaging the second clutch C2 with the even-numbered drive gear stage selected in this way, the transmission 4 is set to an even-numbered gear stage (second speed, fourth speed, or sixth speed).

  When the synchromesh of the 3-7 speed synchromesh mechanism 81 is slid to the left, the 3rd speed drive gear 43 is coupled to the inner main shaft 100 to select the 3rd speed, and when it is slid to the right, the 7th speed is driven. The gear 47 is coupled to the inner main shaft 100 to select the seventh speed. When the synchromesh of the 5-speed synchromesh mechanism 82 is slid in the right direction, the 5-speed drive gear 45 is coupled to the inner main shaft 100, and the 5-speed gear stage is selected. In a state where none of the gears 43, 47, 45 is selected by the synchromesh mechanisms 81, 82, the rotation of the carrier 73 of the planetary mechanism 70 is transmitted to the countershaft 200 via the gear 43 connected thereto, so that the first speed The gear position is selected. By engaging the first clutch C1 with an odd drive gear selected, the transmission 4 is set to an odd gear (1st, 3rd, 5th, or 7th).

  Determination of the shift speed to be realized in the transmission 4 and control for realizing the shift speed (selection of the shift speed in the first speed change mechanism and the second speed change mechanism, ie, synchro switching control, and control of the first clutch and the second clutch Engagement and disengagement control, etc.) are performed by the electronic control unit 10 according to the driving situation as is well known, but in this embodiment, particularly when the driving situation is in the motor lock state (stall state), By performing control for releasing the motor lock state including switching of the gear stage and engagement and disengagement of the first clutch and the second clutch which are not conventionally performed, the motor lock state is forcibly released, thereby It is intended to prevent the occurrence of failure due to heat of the switching element (see FIG. 2). This will be described below.

  A control example for releasing the motor lock state executed by the electronic control unit 10 will be described with reference to FIGS. The release control process in the motor lock state shown in FIG. 4 is started when it is determined to switch to EV traveling (motor independent traveling) that is vehicle traveling using only the motor 3, and is repeatedly executed during EV traveling. The During EV traveling, a current exceeding a certain level is supplied to the motor 3, and the motor 3 is in a state of generating torque.

  The motor lock state release control process is roughly divided into a motor lock state detection process S1 (lock state detection means) and a motor lock state release process S2 (lock state release means). First, in the motor lock state detection process S1 (lock state detection means), it is determined whether or not the rotation of the motor 3 is locked by an external force. FIG. 5 shows a specific example of the motor lock state detection process S1.

  In step S11, according to the vehicle inclination angle and the motor rotation speed acquired as control parameters, it is determined whether the vehicle inclination is equal to or greater than a predetermined value and the rotation speed of the motor 3 is equal to or less than the predetermined rotation speed. That is, in a state in which the vehicle does not move back and forth at all while the vehicle is stationary in the middle of a slope even though a certain current or more is supplied to the motor 3 (one of the modes in which the motor 3 is locked). It is determined whether or not there is. When it is determined that the vehicle inclination is equal to or greater than the predetermined value and the rotation speed of the motor 3 is equal to or less than the predetermined rotation speed (YES in step S11), it is determined that the motor is locked (step S15).

  In step S12, according to the accelerator pedal opening and the brake pedal opening acquired as control parameters, it is determined whether or not both of these openings are equal to or greater than a predetermined value. That is, it is determined whether or not the vehicle is stopped (one of the modes in which the motor 3 is locked) by both steps of the driver simultaneously operating the accelerator pedal and the brake pedal. When it is determined that both the accelerator pedal opening and the brake pedal opening are equal to or greater than the predetermined value, that is, when both the pedals are depressed (YES in step S12), it is determined that the motor is locked (step S15).

  In step S13, after the motor control means 20 energizes the stator winding of any phase of the motor 3 for a predetermined time, is the rotational speed of the motor 3 less than or equal to a predetermined rotational speed including, for example, 0? Determine whether or not. If it is determined that the rotation speed of the motor 3 is equal to or lower than the predetermined rotation speed (YES in step S13), it is determined that the motor is locked (step S15). That is, in this case, if the rotation speed of the motor 3 is equal to or lower than the predetermined rotation speed, an energization current flows through the stator winding of any phase of the motor 3 and the switching element of the inverter 20 corresponding to this energization phase. Since excessive local heat generation may occur, it is determined that the motor is locked.

  In step S14, according to the inverter element temperature acquired as the control parameter, at least one of the temperatures of the switching elements of the inverter 20 corresponding to the stator windings of the phases of the motor 3 energized by the motor control means 20 is determined. It is determined whether or not the temperature has risen above a predetermined temperature. The predetermined temperature is a preset temperature and does not affect the aging of the motor 3. If it is determined that at least one of the temperatures of the switching elements has risen above a predetermined temperature (YES in step S14), it is determined that the motor is locked (step S15). That is, in this case, the current is already flowing only in the stator winding of any phase of the motor 3 and the switching element of the inverter 20 corresponding to this energized phase, and excessive local heat is generated. Because there is, it is determined that the motor is locked.

  If it is determined “NO” in all the processes of steps S11 to S14, it is determined that the motor is not locked (step S16).

  Returning to FIG. 4, in the motor lock state release process S <b> 2 (lock state release means), a disturbance is generated in the transmission 4 to forcibly rotate the motor 3 in the lock state even at least with a minute rotation angle. (Say to release the motor lock state). By forcibly rotating the motor 3 in the locked state even a little, the energizing current continues to flow, and no current flows from one switching element in the inverter 20 that may cause excessive local heat generation. The path through which the current flows is changed (switched) to any one of the other switching elements. FIG. 6 shows a specific example of the motor lock state releasing process S2.

  Step S21 determines whether or not the motor is locked. This determination is based on the determination of whether or not the motor is locked in the motor lock state detection process S1 described above (see steps S15 and S16 in FIG. 5). If it is determined that the motor is not locked (YES in step S21), the energization current continues to flow through the stator winding of any phase of the motor 3 and the switching element of the inverter 20 corresponding to this energization phase, resulting in excess. Since there is no possibility that local heat generation may occur, the process is terminated without executing various processes (steps S22 to S26) for releasing the motor lock state as described later.

  On the other hand, when it is determined that the motor is locked (NO in step S21), the energization current continues only to the stator winding of any phase of the motor 3 and the switching element having the inverter 20 corresponding to this energization phase. Since there is a possibility that excessive local heat generation may occur in the switching element as it is, various processes (steps S22 to S25) for releasing the motor lock state as described below are executed to avoid this. .

  Step 22 controls the transmission 4 to change the gear position from the first speed drive gear to the second speed drive gear. Specifically, the one-way clutch 41 (on state) that has locked the ring gear 75 in order to generate torque equivalent to the first speed in the carrier 73 according to the rotation of the motor 3 is in a state in which the ring gear 75 is not locked ( Off state). Further, in the second speed change mechanism that realizes even-numbered speed stages, control is performed in which the synchromesh of the 2-6 speed synchromesh mechanism 83 is slid leftward to couple the second speed drive gear 42 to the secondary shaft 400. As a result, the state in which the first gear is selected in the transmission 4 is exited, and the second gear is selected.

  Step S23 engages and controls at least one of the first clutch C1 that transmits mechanical power to the odd-numbered stages and the second clutch C2 that transmits mechanical power to the even-numbered stages, Both of the second clutches C2 are brought into a completely engaged state (that is, both gripped states). The torque corresponding to the first speed inputted from the motor 3 and the torque due to the external force inputted from the driving wheel are one in the same transmission path before the both grip control, specifically, the inner main shaft 100, the third speed drive. The gear 43 and the countershaft 200 were traced, and the motor was locked because they were in balance. However, by performing the above-mentioned both grip control, the torque corresponding to the first speed inputted from the motor 3 and the torque due to the external force inputted from the driving wheel are respectively transmitted to two different transmission paths via the dual clutch mechanism. Can be dispersed. Therefore, when the first clutch C1 and the second clutch C2 are both gripped, the torque corresponding to the first speed input from the motor 3 that has been balanced in the motor lock state before the both grip control and the input from the driving wheel are input. It is possible to slightly break the balance with the torque generated by the external force. If it does so, rotation of the motor 3 will be accept | permitted although it is slight. If the motor 3 can be rotated even a little from the motor lock state that has not been rotating at all, one of the switching elements in which the energization current continued to flow in the motor lock state and any one of the other switching elements in which the current did not flow Since the path through which the current flows is switched, the occurrence of a failure due to the heat of the switching element can be prevented.

  Further, when the first clutch C1 and the second clutch C2 are both gripped, the rotation of the inner main shaft 100 or the outer main shaft 101 is transmitted to the oil pump drive shaft 90 via the reverse drive gear 46. Then, the oil pump OP is driven. When the oil pump OP is driven, vibration is generated in the motor 3 according to its mechanical operation. When the motor 3 vibrates, the motor lock state is released, and the current flows from one switching element in which the energization current has continued to flow in the motor lock state to any one of the other switching elements in which no current flows. Therefore, the occurrence of a failure due to the heat of the switching element can be prevented.

  As described above, the motor lock state can be released by setting both the first clutch C1 and the second clutch C2 to both grips in a completely engaged state. However, the allowable rotation of the motor 3 is really slight. Therefore, in order to rotate the motor 3 more reliably, one of the first clutch C1 and the second clutch C2 in the fully engaged state is controlled to the half-clutch state (step S24). Specifically, the second clutch C2 is caused to slip (slip) by reducing the fastening force of the second clutch C2 that transmits mechanical power to the even stages. According to this, the torque corresponding to the first speed input from the motor 3 out of the two different transmission paths via the dual clutch mechanism is released according to the slip of the second clutch C2. As a result, the balance between the torque corresponding to the first speed input from the motor 3 and the torque generated by the external force input from the drive wheel can be greatly broken, and thus the rotation of the motor 3 is allowed more reliably. Therefore, since the motor 3 can rotate even when the drive wheels are fixed, in-phase energization can be avoided.

  In step S25, the engine 2 is pushed and started. That is, by setting both the first clutch C1 and the second clutch C2 to the fully engaged state and then setting the second clutch C2 to the half-clutch state, the allowable rotation amount of the motor 3 can be further increased. Since the torque thus transmitted can be transmitted to the engine 2, the engine 2 is pushed and started. By starting the engine 2, not only the torque corresponding to the first speed input from the motor 3 but also the torque input from the engine 2 can be used to maintain a balance with the torque generated by the external force input from the drive wheels. . Therefore, since the burden on the motor 3 can be reduced, it is possible to constantly avoid in-phase energization.

  In the above-described embodiment, the engine 2 is started after the engagement force of the second clutch C2 is reduced to cause the second clutch C2 to slip (slip) (steps S24 and S25). However, the present invention is not limited to this, and the engine 2 may not be started. However, in that case, it is preferable that the second clutch C2 is completely engaged again after the engagement force of the second clutch C2 is temporarily reduced to cause the motor 3 to idle. Further, it is preferable that the engagement control of the second clutch C2 is repeatedly performed so that the energized phase is switched each time.

  As described above, in the present invention, when the motor lock state is detected, the engagement / disengagement control (shift control) of the shift speed in the first transmission mechanism and the second transmission mechanism, the first clutch C1, and the second clutch The transmission 4 is mechanically operated by performing engagement control of both clutches of the clutch C2. In particular, special control that is not performed at the time of normal traveling control is performed such that both the first clutch C1 and the second clutch C2 are simultaneously engaged, and the second clutch C2 that is simultaneously engaged is set to a half-clutch state. As a result, the balance between the torque input from the motor 3 and the torque generated by the external force input from the drive wheel can be slightly lost due to the external force, and the motor 3 can be rotated even slightly. By doing so, it prevents in-phase energization. In the mechanical operation of the transmission 4 by the above control, there is an advantage that it takes very little time for torque to be released by the external force input from the drive wheels. Further, since the above control can be realized without the need to start the engine 2, fuel is not consumed wastefully.

1 Hybrid vehicle 2 Engine 3 Electric motor (motor)
4 Transmission (transmission)
5 Differential mechanism 6R, 6L Drive shaft 7R, 7L Drive wheel 10 Electronic control unit 20 Electric motor (motor) control means (inverter)
21 U-phase arm 22 V-phase arm 23 W-phase arm 30 Battery 41 One-way clutch 70 Planetary gear mechanism 71 Sun gear 72, 74 Planetary gear 73 Carrier 75 Ring gear C1 First clutch C2 Second clutch OP Oil pumps Q11 to Q32 Switching element L Battery drive line 90 Oil pump drive shaft 100 Inner main shaft 101 Outer main shaft 200 Counter shaft 300 Idle gear 400 Secondary shaft 500 Reverse shaft

Claims (11)

It has an internal combustion engine and an electric motor as a drive source,
Mechanical power from the output shaft of the internal combustion engine and the electric motor is received by a first input shaft connected to the electric motor, and any one of a plurality of shift stages is engaged, and the first input shaft and driving wheels are engaged. A first transmission mechanism capable of engaging with
The mechanical power from the output shaft of the internal combustion engine is received by the second input shaft, and any one of a plurality of shift stages can be engaged to engage the second input shaft and the drive wheel. A second speed change mechanism;
First connection / disconnection means capable of switching between engagement and disengagement between the internal combustion engine output shaft and the first input shaft;
A second connecting / disconnecting means capable of switching between engagement and disengagement between the internal combustion engine output shaft and the second input shaft;
In a hybrid vehicle comprising a control device capable of controlling the engagement state of the shift speed in the first transmission mechanism and the second transmission mechanism and the engagement state of the first connection / disconnection means and the second connection / disconnection means,
The controller is
Lock detecting means for detecting a lock state of the electric motor;
At the time of detection of the locked state by the lock detection means, the gear position of the first speed change mechanism is released while the gear position of any one of the second speed change mechanism is engaged, and the first connecting / disconnecting means or A hybrid vehicle comprising: a lock state releasing means for changing an engagement state of at least one of the second connecting / disconnecting means.   The lock state releasing means changes the engaged state of the first connecting / disconnecting means to an engaged state in which the output shaft of the internal combustion engine and the first input shaft are engaged with each other. The hybrid vehicle according to claim 1, wherein the hybrid vehicle is brought into a fastening state in which the output shaft of the internal combustion engine and the second input shaft are engaged.   3. The hybrid vehicle according to claim 2, wherein the lock state releasing unit further reduces a fastening force of at least one of the first connecting / disconnecting unit and the second connecting / disconnecting unit brought into the engaged state.   The hybrid vehicle according to any one of claims 1 to 3, wherein the lock detection means detects the lock state during motor travel, which is vehicle travel using only an electric motor.   5. The locked state releasing means pushes and starts the internal combustion engine in response to changing an engagement state of at least one of the first connecting / disconnecting means and the second connecting / disconnecting means. The described hybrid vehicle.   The lock detection means determines that the motor is in a locked state when the vehicle is inclined more than a predetermined angle and the rotation speed of the motor is equal to or less than a predetermined rotation speed. The hybrid vehicle according to any one of claims 1 to 5.   When the lock detection means is continuously energized for a predetermined time only to the stator winding of any phase of the motor, and the rotation speed of the motor is equal to or less than a predetermined rotation speed, The hybrid vehicle according to claim 1, wherein the electric motor is determined to be in a locked state.   The lock detection means determines that the electric motor is in a locked state when both an accelerator pedal and a brake pedal of the vehicle are simultaneously operated. The hybrid vehicle described in 1.   When the temperature of at least one of the switching elements provided corresponding to the stator windings of the plurality of phases of the electric motor rises above a predetermined temperature, the lock detection unit is 6. The hybrid vehicle according to claim 1, wherein the electric motor is determined to be in a locked state.   The lock state releasing means drives an oil pump engaged with at least one of a first input shaft of the first transmission mechanism and a second input shaft of the second transmission mechanism. The hybrid vehicle according to any one of 9. A control method for a hybrid vehicle having an internal combustion engine and an electric motor as a drive source,
The hybrid vehicle
The internal combustion engine output shaft and mechanical power from the electric motor are engaged with the electric motor by the internal combustion engine output shaft and the mechanical power from the electric motor received by the first input shaft connected to the electric motor, and a plurality of A first speed change mechanism capable of engaging any one of the shift speeds to engage the first input shaft and the drive wheel;
The mechanical power from the output shaft of the internal combustion engine is received by the second input shaft, and any one of a plurality of shift stages can be engaged to engage the second input shaft and the drive wheel. A second speed change mechanism;
First connection / disconnection means capable of switching between engagement and disengagement between the internal combustion engine output shaft and the first input shaft;
A second connecting / disconnecting means capable of switching between engagement and disengagement between the internal combustion engine output shaft and the second input shaft;
A control device capable of controlling the engagement state of the shift speed in the first transmission mechanism and the second transmission mechanism and the engagement state of the first connection / disconnection means and the second connection / disconnection means;
The controller is
Detecting the lock state of the electric motor during traveling of the vehicle using only the electric motor;
Engaging one of the gears of the second transmission mechanism and releasing the gear of the first transmission mechanism when detecting the locked state;
The engagement state of the first connecting / disconnecting means is the fastening state in which the output shaft of the internal combustion engine and the first input shaft are engaged, and the engaging state of the second connecting / disconnecting means is the output shaft of the internal combustion engine. The first connecting / disconnecting state in which the second input shaft is engaged, or both the first connecting / disconnecting means and the second connecting / disconnecting means are in the engaging state, and further in the engaging state. And a step of reducing the fastening force of at least one of the second connecting and disconnecting means.

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