JP2017165131A - Control device for hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a hybrid vehicle, which is able to inhibit sudden advancement or the like of the vehicle without intention of a driver during stop of the vehicle.SOLUTION: A control device for a hybrid vehicle comprises: an engine 16; a rotary electric machine 18 provided downstream of the engine 16; a transmission 28 connected to an output shaft 22 of the rotary electric machine 18, the transmission 28 having a mechanical oil pump MOP driven by rotation input to the transmission; an engine disconnection clutch 20 interposed between the engine and the rotary electric machine; and an electrically-driven oil pump MOP driven by an electric motor 42 regardless of rotations of the engine and rotary electric machine. The control device is configured so as to switch at least a transmission to a neutral if a mechanical oil pump is driven as a result of rotation of the output shaft of the rotary electric machine when the engine is stopped and the vehicle is in a D range EV stop condition in which brake is applied to stop the vehicle. Accordingly, the vehicle is prevented from suddenly advancing without intention of a driver.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device for a hybrid vehicle including a plurality of power sources and an electric oil pump.

  Conventionally, in addition to an internal combustion engine (engine) generally used as a power source for a vehicle, a hybrid vehicle equipped with a rotating electric machine as a second power source is known. This type of vehicle tends to be configured to perform a so-called EV mode operation in which only the rotating electrical machine is operated with the engine stopped in order to reduce fuel consumption at low output where high output is not required. It is in.

  An example of such a hybrid vehicle using an engine and a rotating electrical machine as a power source is described in Patent Document 1. In the hybrid vehicle described in Patent Document 1, an engine, a clutch provided downstream of the engine, a rotating electrical machine provided downstream from the clutch, and an automatic transmission provided downstream from the rotating electrical machine. An automatic transmission equipped with a mechanical oil pump is disposed in the power transmission path. Furthermore, an electric oil pump that is driven regardless of the rotation of an engine or a rotating electrical machine as a power source is provided. When the engine is stopped regardless of whether the vehicle is running or the vehicle is stopped, the electric oil pump is operated to ensure the hydraulic pressure of the automatic transmission or the like.

  Further, in a hybrid vehicle, it is determined whether to use the rotating electric machine as an electric motor or a generator depending on the state of charge (SOC) of the battery, and when the SOC does not exceed a predetermined value, the electric motor as the power source Use is prohibited. Further, even in the case of an electric oil pump, it is preferable that its use is prohibited when the use conditions are not appropriate from the viewpoint of durability or the like (such as high temperature).

JP 2000-179679 A

  By the way, in the hybrid vehicle described in Patent Document 1, although there is a description regarding the control of the operation of the electric oil pump, when the vehicle is stopped, the electric oil pump is stopped and the mechanical oil pump is operated. No consideration is given to the control when it must be activated.

  Therefore, for example, during EV mode operation with only the rotating electrical machine operated, the vehicle is stopped with the shift lever in the D range at an intersection or the like, so-called start standby, and under the use conditions as described above As a result of the restriction, the electric oil pump may be stopped and the mechanical oil pump may be operated. In such a case, for example, when the rotating electrical machine is operated to drive the mechanical oil pump, a creeping force is generated on the vehicle due to the torque of the rotating electrical machine, causing the vehicle to jump out and start unintended by the driver. As a result, there is a possibility that the driver who is waiting to start will feel uncomfortable.

  An object of the present invention is to provide a control device for a hybrid vehicle that can prevent the vehicle from jumping out and starting unintended by the driver while the vehicle is stopped.

In order to solve the above problems, a control device for a hybrid vehicle according to the present invention provides:
Engine,
A rotating electrical machine provided downstream of the engine;
A transmission connected to an output shaft of the rotating electrical machine, the transmission including a mechanical oil pump driven by input rotation to the transmission;
A clutch interposed between the engine and the rotating electrical machine;
An electric oil pump driven by an electric motor regardless of the rotation of the engine and the rotating electrical machine;
In a control apparatus for a hybrid vehicle having
The controller is
When the mechanical oil pump is driven in accordance with the rotation of the output shaft of the rotating electrical machine when the engine is stopped and the vehicle is in a D range EV stopping state where braking is stopped, at least the speed change is performed. The machine is configured to switch to a neutral state.

  According to the present invention having the above-described configuration, when the engine is stopped and the vehicle is in a braking stop state in the D range EV, the generation command for the driving torque of the rotating electrical machine is stopped and the electric oil pump Therefore, the transmission is maintained at a predetermined start position and the creep force is maintained at zero. Here, instead of or in addition to the operation of the electric oil pump, in order to operate the mechanical oil pump driven by the input rotation to the transmission, the mechanical oil pump is rotated along with the rotation of the output shaft of the rotating electrical machine. When driven, at least the transmission is switched to the neutral state. Therefore, even if the output shaft of the rotating electrical machine is rotated, the transmission is in a neutral state, so that creep force is not generated and is maintained at zero.

  As described above, according to the present invention, it is possible to prevent the vehicle from jumping out and starting unintended by the driver while the vehicle is on standby for starting at the D range EV stop.

The schematic diagram of the schematic structure of the hybrid vehicle which concerns on one Embodiment of this invention is shown. It is a control block diagram of the principal part of the hybrid vehicle of FIG. 2 is a flowchart for controlling the hybrid vehicle in FIG. 1.

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

  FIG. 1 is a schematic diagram of a schematic configuration of a hybrid vehicle drive device 10 and a hydraulic device 12 according to an embodiment of the present invention. In FIG. 1, a solid line indicates a driving force transmission path, and a broken line indicates a hydraulic oil supply path.

  The drive device 10 includes an internal combustion engine (hereinafter referred to as an engine) 16 and a rotating electrical machine (hereinafter also referred to as a motor generator or MG) 18 as power sources. The motor generator 18 is provided on the downstream side of the engine 16 (that is, on the wheel side in the driving force transmission path). An output shaft member (that is, a crankshaft) 16a of the engine 16 can be releasably connected to an input member 22 (corresponding to a rotating shaft member of the motor generator 18) via an engine disconnecting clutch device (hereinafter referred to as a k0 clutch) 20. When k0 clutch 20 is connected (that is, engaged), engine 16 and motor generator 18 are connected in series via k0 clutch 20. The k0 clutch 20 is a device capable of connecting / disconnecting the driving force from the engine 16, operates by receiving supply of hydraulic oil, and can be selectively engaged or disengaged. An engagement element is provided.

  A torque converter 26 is provided on the downstream side of the engine 16 and the motor generator 18 as power sources. The torque converter 26 includes a pump impeller 26a as an input side rotating element connected to the input member 22, a turbine runner 26b as an output side rotating element connected to the input shaft member 28a of the transmission 28, and a gap therebetween. And a stator 26c provided with a one-way clutch. The torque converter 26 is provided with a lockup clutch 30. The lockup clutch 30 operates by receiving supply of hydraulic oil, and can be controlled to an arbitrary state between an engaged state and a released state. In the engaged state of the lockup clutch 30, the driving force of the power source is directly transmitted to the transmission 28 without passing through the hydraulic oil filled in the torque converter.

  A transmission 28 is connected to the downstream side of the torque converter 26. With this transmission 28, the rotation of the driving force from the power source transmitted through the torque converter 26 can be shifted to a wheel 34 side with a predetermined gear ratio. The transmission 28 is configured as a stepped automatic transmission, and includes a friction engagement element such as a clutch or a brake that engages or releases a rotation element of a gear mechanism that generates a gear ratio of each shift stage. Configured.

  The friction engagement elements of these transmissions 28 operate upon receiving hydraulic oil. A shift lever (not shown) is selectively positioned by the driver in one of a plurality of ranges (that is, modes) including a P (parking) range, an N (neutral) range, a D (drive) range, and an R (reverse) range. . Depending on the position of the shift lever, the friction engagement elements of the transmission 28 are brought into an engaged state or a released state, respectively. When the D range (that is, the forward travel mode) is selected, the friction engagement element is operated so as to generate a gear ratio of a predetermined shift stage from among a plurality of shift stages, and the vehicle is stopped and started. Is set by selecting the first gear. The transmission 28 may be a continuously variable automatic transmission.

  An output member 38 is coupled to the downstream side of the transmission 28, and a wheel 34 is connected to the output member 38 via a differential device 40. As a result, the rotational driving force transmitted from the power source to the input member 22 is shifted by the transmission 28 and transmitted to the output member 38, and the rotational driving force transmitted to the output member 38 is transmitted to the wheel via the differential device 40. The drive device 10 is configured so as to be transmitted to 34.

  In such a drive device 10, when the vehicle starts or runs at a low speed, the k0 clutch 20 is disengaged, the engine 16 is stopped, and only the rotational driving force of the motor generator 18 is transmitted to the wheels 34. The At this time, the motor generator 18 receives a supply of electric power from a battery device described later and generates a driving force. The engine 16 is cranked and started when the k0 clutch 20 is engaged in a state where the rotational speed of the motor generator 18 (that is, the traveling speed of the vehicle) is a certain level or more. The engine 16 can be started independently by a starter motor 17 provided in the engine 16 as described later. After the engine 16 is started, the rotational driving forces of both the engine 16 and the motor generator 18 are transmitted to the wheels 34. At this time, the motor generator 18 generates either a state of generating power by the rotational driving force of the engine 16 or a state of generating driving force by the electric power supplied from the battery device, depending on the state of charge (SOC) of the battery device. Can be a friend. Further, when the vehicle is decelerated, the k0 clutch 20 is released, the engine 16 is stopped, and the motor generator 18 is in a state of generating electric power by the rotational driving force transmitted from the wheels 34. The electric power generated by the motor generator 18 is stored in the battery device. When the vehicle stops, both the engine 16 and the motor generator 18 are stopped, and the k0 clutch 20 is released.

  At the time of shifting the transmission speed of the transmission 28, the lockup clutch 30 is released, and the torque converter 26 transmits the driving force via the hydraulic oil. In the vehicle starting stage (including before starting), the lockup clutch 30 is brought into an engaged state or a released state depending on conditions.

  Next, the hydraulic device 12 will be described. In FIG. 1, a pressure regulating valve and the like are omitted. As shown in FIG. 1, the hydraulic device 12 is a hydraulic source for supplying hydraulic oil to each part of the drive device 10 (for example, the k0 clutch 20, the engagement element of the transmission 28, the torque converter 26, and the lockup clutch 30). As shown in FIG. 2, the pump includes two types of pumps, a mechanical oil pump MOP and an electric oil pump EOP. The mechanical oil pump MOP is an oil pump that is operated by the driving force of a power source. In this embodiment, the mechanical oil pump MOP is connected to the pump impeller 26a of the torque converter 26, and is connected to the output shaft of the motor generator 18. The pump impeller 26a, which is an input side rotating element that rotates with rotation, is configured to operate as it rotates, and is driven by the rotational driving force of the motor generator 18 and / or the rotational driving force of the engine 16.

  As shown in FIG. 1, the electric oil pump EOP is an oil pump that operates by the driving force of the electric motor 42 regardless of the driving force of the power source. In the present embodiment, the electric oil pump EOP operates in a state in which hydraulic oil of a necessary flow rate is not supplied from the mechanical oil pump MOP in principle when the vehicle is traveling at a low speed or when the vehicle is stopped.

  The hybrid vehicle includes an electronic control unit (ECU) configured as a control device for controlling operations of the engine 16, the motor generator 18, the k0 clutch 20, the transmission 28, the lockup clutch 30, the electric motor 42, and the like. 60. The ECU 60 is configured as a computer and is electrically connected to various sensors and actuators. For example, a crank position sensor 62 for detecting the crank angle of the crankshaft 16a of the engine 16 (which also functions as an engine speed sensor), and a depression amount (accelerator opening) of an accelerator pedal operated by a driver are detected. Accelerator opening sensor 64 for detecting, brake switch 66 that switches on and off according to the state of the brake pedal operated by the driver, and position of the shift lever (selected range (mode)) Shift position sensor 68, tilt sensor 70 for detecting the tilt angle of the vehicle, vehicle speed sensor 72 for detecting the vehicle speed, temperature sensor 74 for detecting the temperature of the electric motor 42, and for detecting the remaining battery level The battery sensor 76 is electrically connected to the ECU 60 and they are Each sends output signals to the ECU 60 Re, ECU 60 acquires a detected value based on their signal.

  The ECU 60 controls the operations of the engine 16, the starter motor 17, the motor generator 18, the k0 clutch 20, the transmission 28, the lockup clutch 30, the electric motor 42, and the like based on the acquired detection values. A control signal is output to each of these units. In FIG. 2, since it is obvious to those skilled in the art, the control by the ECU 60 is shown in a simplified manner. For example, it will be understood that outputting a control signal to the internal combustion engine 16 and controlling it includes controlling the opening of the throttle valve and fuel injection.

  Further, a battery 44 is connected to the motor generator 18 via a PCU (power control unit) including an inverter, and the PCU is further connected to the ECU 60. The inverter converts the direct current of the battery 44 into a three-phase alternating current and supplies it to the motor generator 18, while converting the three-phase alternating current generated by the motor generator 18 into a direct current and supplies the three-phase alternating current to the battery 44. A bridge circuit is provided. This three-phase bridge circuit is configured by electrically connecting, for example, six power transistors. By switching on and off these power transistors, the direction of current between the motor generator 18 and the battery 44 is changed. Switch.

  Further, the ECU 60 has a function of detecting or controlling a current value supplied from the battery 44 to the motor generator 18 or a current value generated by the motor generator 18. The ECU 60 has a function of controlling the rotational speed of the motor generator 18 and a function of detecting and controlling the state of charge (SOC) of the battery 44.

  Now, in the hybrid vehicle having the above configuration, a flowchart showing an example of the control routine of FIG. 3 for the control when the D range is selected while the vehicle is stopped, particularly when the engine is stopped. This will be explained based on. However, mainly the control before starting the vehicle described below is substantially performed by the pre-start control unit of the ECU 60 at a predetermined cycle. As described above, in the vehicle, when the vehicle is stopped and started, the k0 clutch 20 is released, the engine 16 is stopped, and the rotational driving force of the motor generator 18 is set when starting. Only is used.

  Therefore, when reaching step S301 in FIG. 3, the vehicle is in a stopped state, the k0 clutch 20 is in a released state, and the engine 16 is in a stopped state. Whether or not the vehicle is stopped can be determined based on whether or not the vehicle speed detected using the vehicle speed sensor 72 is zero.

  In the present embodiment, the ECU 60 can further have a condition that the brake pedal is stepped on as a condition for determining whether or not the vehicle is stopped. The ECU 60 detects that the brake pedal is being depressed based on the output of the brake switch that is turned on when the brake pedal is depressed, and the ECU 60 activates the k0 clutch 20 when the vehicle is stopped. A program for setting the engine 16 to a stopped state is provided in advance.

  In step S301 in FIG. 3, when the vehicle is in a stopped state (stopped) and the engine is in a stopped state, it is determined whether or not the D range (that is, the forward travel mode) is selected. It is determined whether or not the vehicle is in the EV stop state, whether or not the electric oil pump EOP is being activated, and whether or not there is a torque command to the motor generator 18. The selection of the D range can be detected using the shift position sensor 68, the EV mode can be detected using the crank position sensor 62 of the engine 16, and the vehicle can be stopped using the vehicle speed sensor 72. Further, whether or not the electric oil pump EOP is being activated can be determined by the presence or absence of an output signal from the ECU 60 to the electric motor 42. Further, the presence or absence of a torque command to motor generator 18 can be determined using an output signal from accelerator opening sensor 64. Note that, when the vehicle is in the D range EV stop state, the engine is in a stopped state, so that the engine disconnecting clutch 20 is in a released state as described above. In step S301, if any one of the D range EV stop state, the electric oil pump EOP is activated, or no torque command to the motor generator 18 is negatively determined, the routine ends. On the other hand, when a positive determination is made, the process proceeds to the next step S302.

  In step S302, it is determined whether intermittent engine operation is possible. The intermittent operation of the engine means that the engine is independently started and operated for the purpose of protecting the system or improving the efficiency regardless of the driver's intention to drive. For example, when the state of charge (SOC) of the battery is lower than a predetermined value, or when the temperature of the engine cooling water and / or the exhaust gas purifying catalyst is lower than the predetermined value, the engine is warming up, etc. The engine is started and operated. Therefore, the intermittent operation of the engine means that the SOC exceeds a predetermined value, the engine has been warmed up, and it is not necessary to start and operate the engine.

  Therefore, if an affirmative determination is made in step S302, the process proceeds to step S303, in which it is determined whether or not the electric oil pump EOP can be used. This determination as to whether or not it can be used is made, for example, based on whether or not the temperature exceeds a predetermined threshold based on an input signal to the ECU 60 from a temperature sensor provided in the electric motor 42.

  If it is determined in step S303 that the temperature of the electric motor 42 does not exceed the predetermined threshold value and the electric oil pump EOP can be used continuously, the routine ends. On the other hand, when a negative determination is made in step S303 that the temperature exceeds a predetermined threshold value and the use is not possible, the process proceeds to step S304, and the motor generator 18 is operated so as to drive the mechanical oil pump MP. At the same time, in the transmission 28 in which the first gear is selected and set so as to correspond to the stoppage of the D range EV, one or more friction engagement elements are engaged based on a gear change command from the ECU 60. Alternatively, the neutral state corresponding to the N range is formed by being released. As a result, even if the motor generator 18 is operated to drive the mechanical oil pump MP, the driving force is interrupted by the transmission 28 in the neutral state, so that no creep force is generated. In step S304 or after that, when the neutral state is reached, the electric motor 42 is stopped and the electric oil pump EOP is also stopped.

  If a negative determination is made in step S302, the process proceeds to step S305 to determine whether or not the battery needs to be charged. This determination is performed in order to confirm whether or not the state of charge SOC of the battery has become equal to or lower than a predetermined value and the motor generator 18 cannot be operated. If an affirmative determination is made in step S305, that is, it is determined that charging is required, the process proceeds to step S306, and the engine disconnecting clutch 20 is engaged. The engagement of the engine disconnection clutch 20 is achieved by supplying hydraulic oil for switching to the engine disconnection clutch 20 from the electric oil pump EOP, since the electric oil pump EOP is maintained while being started. Is done. Then, almost simultaneously with the engagement of the engine disconnecting clutch 20, a signal is sent from the ECU 60 to the starter motor 17, and the engine 14 is started. In transmission 28, one or a plurality of friction engagement elements are brought into an engaged state or a released state based on a shift command from ECU 60, and a neutral state corresponding to the N range is formed. As a result, the motor generator 18 connected to the engine 14 by the engagement of the engine disconnecting clutch 20 can be driven by the engine 14 as a power source to generate electric power. On the other hand, even if the motor generator 18 is driven by the engine 14, the driving force is interrupted by the transmission 28 in the neutral state, so that no creep force is generated.

  Furthermore, if a negative determination is made in step S305, that is, a determination that battery charging is not necessary, the process proceeds to step S307, and only the starter motor 17 of the engine 14 is started. This is a negative determination in step S302, that is, the intermittent operation of the engine is not possible. In other words, the SOC does not exceed a predetermined value, but the engine warm-up is not completed, and a negative determination in step S305. The battery is charged so that it is not necessary, and simply warming up is facilitated by starting and running the engine. In this case, since the engine disconnecting clutch 20 is released, the driving force is not transmitted to the downstream motor generator 18 and the transmission 28, and no creep force is generated.

  As is apparent from the above description, according to the above-described embodiment of the present invention, since the creep force does not occur while the vehicle is waiting for starting at the D range EV stop, the vehicle jumps out and starts without the driver's intention. Etc. can be reliably suppressed.

  However, the said embodiment is an illustration to the last and is not restrictive. The scope of the present invention is intended to include the scope defined by the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 10 Drive apparatus 12 Hydraulic apparatus 16 Engine 18 Rotating electric machine (motor generator)
20 Engine disconnection clutch 26 Torque converter 28 Transmission 42 Electric motor MOP Mechanical oil pump EOP Electric oil pump

Claims (1)

Engine,
A rotating electrical machine provided downstream of the engine;
A transmission connected to an output shaft of the rotating electrical machine, the transmission including a mechanical oil pump driven by input rotation to the transmission;
A clutch interposed between the engine and the rotating electrical machine;
An electric oil pump driven by an electric motor regardless of the rotation of the engine and the rotating electrical machine;
In a control apparatus for a hybrid vehicle having
The controller is
When the mechanical oil pump is driven in accordance with the rotation of the output shaft of the rotating electrical machine when the engine is stopped and the vehicle is in a D range EV stopping state where braking is stopped, at least the speed change is performed. A control apparatus for a hybrid vehicle, characterized in that the machine is configured to switch to a neutral state.

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