JP2012091584A - Hybrid vehicle control device - Google Patents

Abstract

A control device for a hybrid vehicle that prevents occurrence of abnormal noise during traveling is provided.
A hybrid vehicle includes a first clutch provided between an engine and a motor generator and capable of intermittently driving the engine, and a first clutch provided to attenuate transmission torque of the first clutch. When the engine target drive torque or the power generation torque of the motor generator is smaller than the initial torque of the damper mechanism, the power generation amount of the motor generator is increased to increase the power generation torque of the motor generator. Power generation amount increasing means for controlling to exceed the initial torque is provided.
[Selection] Figure 1

Description

  The present invention relates to a technique for preventing the generation of abnormal noise during traveling in a control device for a hybrid vehicle.

  In a hybrid vehicle in which a vehicle is driven using the power of at least one of an engine and a motor, a structure in which the power of the engine and the motor is intermittently connected to a drive shaft by a frictional engagement element (clutch) is known.

  In such a structure, a damper mechanism is provided in the clutch, and torque fluctuation transmitted from the engine side is attenuated by a small hysteresis torque in the forward torsion of the damper mechanism during steady operation of the engine. 2. Description of the Related Art A hybrid vehicle power transmission device (see Patent Document 1) is known in which sudden torque fluctuations that occur when starting and stopping an engine are attenuated by a large hysteresis torque in negative direction torsion.

JP 2006-29363 A

  When the input torque is small, the damper mechanism has a region that exhibits nonlinear characteristics due to the characteristics of the spring. In such a region, the damper mechanism does not function, causing vibration and abnormal noise.

The present invention has been made in view of such problems, and an object of the present invention is to prevent vibration and abnormal noise from being generated in the damper mechanism when the input torque to the frictional engagement element is small.
The purpose is to provide.

  One embodiment of the present invention is applied to a control device that controls the operation of an engine and a motor generator of a hybrid vehicle that travels by the driving force of an engine or a motor generator and operates the motor generator as a generator and can be stored in a battery. The

  The hybrid vehicle includes a first clutch that is provided between the engine and the motor generator and can interrupt the driving force of the engine, and a damper mechanism that is provided in the first clutch and can attenuate the transmission torque of the first clutch. And comprising.

  When the target drive torque of the engine or the power generation torque of the motor generator is smaller than the initial torque of the damper mechanism, the power generation amount of the motor generator is increased so that the power generation torque of the motor generator exceeds the initial torque. Means.

  According to the present invention, when the target drive torque of the engine or the power generation torque of the motor generator is smaller than the initial torque of the damper mechanism, the power generation amount of the motor generator is increased. Thereby, it is possible to prevent abnormal noise and vibration in the first clutch, which are generated when the transmission function of the first clutch is lower than the initial torque of the spring of the damper mechanism and the damper function does not act.

It is a block diagram of an example of the power train of the hybrid vehicle of embodiment of this invention. 1 is a configuration block diagram of a hybrid system according to an embodiment of the present invention. It is explanatory drawing which shows the hysteresis torque of the clutch of embodiment of this invention. It is a flowchart of control of the embodiment of the present invention. It is a schematic block diagram of the other example of the power train of the hybrid vehicle of embodiment of this invention. It is a schematic block diagram of the other example of the power train of the hybrid vehicle of embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram of a power train of a hybrid vehicle according to a first embodiment of the present invention. As shown in FIGS. 5 and 6, the configuration of the power train of the hybrid vehicle, in particular, the position of the second clutch 5 is not limited to that shown in FIG.

  In the power train of the hybrid vehicle shown in FIG. 1, an engine 1 that is a driving force source as an internal combustion engine and a motor generator 2 that generates driving force by electric power are arranged in series in the traveling direction of the vehicle. These driving forces are shifted by the automatic transmission 3 and output to the drive wheels 7 via the differential gear 6.

  The motor generator 2 acts as a motor to generate driving force, or acts as a generator to generate electric power.

  A crankshaft (output shaft) 1 a of the engine 1 and an input shaft 2 a of the motor generator 2 are connected via a first clutch 4. The output shaft 2 b of the motor generator 2 is connected to the input shaft 3 a of the automatic transmission 3. A differential gear 6 is connected to the output shaft 3 b of the automatic transmission 3.

  The automatic transmission 3 selectively engages and disengages a plurality of friction elements (such as a clutch and a brake), and selects a transmission path by a combination of these friction elements to determine a gear position. Therefore, the automatic transmission 3 shifts the rotation from the input shaft 3a to a gear ratio corresponding to the selected gear position, and outputs it to the output shaft 3b.

  The automatic transmission 3 uses one of the plurality of friction elements as the second clutch 5. The automatic transmission 3 combines the power of the engine 1 input via the first clutch 4 and the power input from the motor generator 2 and outputs the combined power to the drive wheels 7.

  The first clutch 4 is configured by, for example, a dry clutch whose engagement state is controlled by hydraulic pressure. The second clutch is configured by a wet multi-plate clutch whose capacity is controlled by hydraulic pressure. In addition, all may be comprised by the dry-type clutch or the wet multi-plate clutch.

  The first clutch 4 includes a damper mechanism 41. The damper mechanism 41 includes a spring and a friction element that restricts the movement of the spring. The damper mechanism 41 is provided to absorb the rotation difference between the connected shafts and to absorb the vibration generated by the first clutch 4 being engaged.

  The first clutch 4 includes a stroke sensor 23 that detects the stroke amount of the first clutch 4.

  The output shaft 1 a of the engine 1 includes an engine rotation speed sensor 10 that detects the rotation speed Ne of the engine 1. The input shaft 2 a of the motor generator 2 includes a motor generator rotational speed sensor 11 that detects the rotational speed Nm of the motor generator 2.

  The automatic transmission 3 includes an automatic transmission input shaft rotational speed sensor 12 that detects an input shaft rotational speed Ni of the automatic transmission 3, and an automatic transmission output shaft rotational speed that detects an output shaft rotational speed No of the automatic transmission 3. A sensor 13.

  The signals output by these sensors are output to the integrated controller 20 described later with reference to FIG.

  The power train of the hybrid vehicle configured as described above has three travel modes according to the engaged state of the first clutch 4. The first travel mode is an electric travel mode (hereinafter referred to as “EV mode”) in which the first clutch 4 is in the released state and travels only with the power of the motor generator 2.

  The second travel mode is a hybrid travel mode (hereinafter referred to as “HEV mode”) in which the first clutch 4 is engaged and travel is performed using the power of both the engine 1 and the motor generator 2.

  The third traveling mode is a slip traveling mode (hereinafter referred to as “WSC (Wet Start Clutch) mode) in which the first clutch 4 is engaged and the second clutch 5 is slip-controlled to travel with the power of the engine 1 and the motor generator 2. "). The WSC mode realizes creep running particularly when the battery SOC is low or the engine water temperature is low. Further, in this mode, the driving force can be output while starting the engine 1 when the engine 1 starts from a stopped state.

  The HEV mode includes an “engine running mode”, a “motor assist running mode”, and a “running power generation mode”.

  The engine travel mode is a mode for driving the drive wheels 7 using only the engine 1 as a drive source. The motor assist travel mode is a mode in which both the engine 1 and the motor generator 2 travel using the drive sources. The traveling power generation mode is a mode in which the motor generator 2 is caused to function as a generator by the driving force of the engine 1 while traveling with the engine 1 as a drive source.

  Further, as a further mode, there is a power generation mode in which the motor generator 2 functions as a generator by the driving force of the engine 1 when the vehicle is stopped.

  The integrated controller 20 controls the engine 1, the motor generator 2, the first clutch 4, the second clutch 5, etc., and switches the traveling mode.

  FIG. 2 is a configuration block diagram of a hybrid system including a control device.

  The hybrid system includes an integrated controller 20, an engine controller 21, a motor generator controller 22, an inverter 8, a battery 9, and the like.

  The integrated controller 20 receives signals from the engine rotational speed sensor 10, the motor generator rotational speed sensor 11, the automatic transmission input shaft rotational speed sensor 12, the automatic transmission output shaft rotational speed sensor 13, and the stroke sensor 23. In addition, signals from the accelerator opening sensor 17 that detects the accelerator opening APO (= actual accelerator opening rAPO) and the SOC sensor 16 that detects the state of charge of the battery 9 are input.

  The integrated controller 20 determines the operating point of the powertrain according to the accelerator opening APO, the battery state of charge SOC, and the vehicle speed VSP (proportional to the automatic transmission output shaft rotational speed No), and the driving force desired by the driver Select a driving mode that can realize In addition, the motor generator controller 22 is commanded with a target motor generator torque or a target motor generator rotation speed. Further, the target engine torque is designated to the engine controller 21. In addition, a drive signal is commanded to the solenoid valve 14 that controls the hydraulic pressure of the first clutch 4 and the solenoid valve 15 that controls the hydraulic pressure of the second clutch 5.

  The engine controller 21 controls the engine 1 so that the engine torque becomes the target engine torque.

  The motor generator controller 22 controls the motor generator 2 via the battery 9 and the inverter 8 so that the torque of the motor generator 2 becomes the target motor generator torque (or the rotational speed of the motor generator becomes the rotational speed of the target motor generator). Control. When the motor generator 2 is used as a generator, the power generation torque of the motor generator is controlled so that the motor generator 2 becomes the target power generation torque.

  The inverter 8 converts the electric power of the battery 9 into a high frequency current and supplies it to the motor generator 2. Further, when the motor generator 2 is in a power generation state, the generated power is converted into a direct current to charge the battery 9.

  Next, the damper mechanism 41 of the first clutch 4 will be described.

  FIG. 3 is an explanatory diagram showing characteristics of the damper mechanism 41 of the first clutch 4 according to the embodiment of the present invention.

  The damper mechanism 41 allows relative rotation between the input side and the output side at a predetermined twist angle according to the input transmission torque by an elastic body such as a spring. Further, the twist angle is provided with hysteresis by a friction element or the like so that a shock does not occur when the direction of the transmission torque changes.

  Here, the damper mechanism 41 acts as a damper by compressing the spring, but a transmission torque of a predetermined value or more is required to compress the spring. This predetermined value is called initial torque.

  Therefore, the damper mechanism 41 cannot act as a damper in a region where the transmission torque input to the first clutch 4 is less than the initial torque. When the damper mechanism 41 does not act, there is a possibility that abnormal noise is generated when there is a change in transmission torque in the first clutch 4.

  Therefore, in the embodiment of the present invention, the following configuration is adopted so that the generation of abnormal noise in the first clutch 4 can be prevented.

  FIG. 4 is a process flowchart executed by the integrated controller 20 according to the embodiment of this invention. Note that the processing of this flowchart is executed by the integrated controller 20 at a predetermined interval (for example, 10 ms).

  First, the integrated controller 20 determines whether or not the target drive torque of the engine 1 is equal to or greater than a predetermined value or whether the power generation torque of the motor generator 2 is equal to or greater than a predetermined value from the current powertrain state ( Step S1).

  Whether or not the driving torque of the engine 1 is equal to or greater than a predetermined value is determined by, for example, whether or not the travel mode is the WSC mode or the accelerator opening APO.

  When the travel mode is the WSC mode, the vehicle speed is low and the target drive torque is also low, so it is determined that the target drive torque is less than a predetermined value. Further, it is determined that the accelerator opening APO is small and the target drive torque based on the accelerator opening APO is less than a predetermined value.

  The predetermined value is set in advance so that the target drive torque of the engine 1 exceeds the initial torque of the damper mechanism.

  Alternatively, the determination may be made based on the power generation torque of the motor generator 2 instead of the target drive torque of the engine 1. When the motor generator 2 is generating power, the integrated controller 20 calculates a power generation torque from the power generation amount. Then, it is determined whether the power generation torque is a value that exceeds the initial torque of the damper mechanism.

  If the determination in step S1 is Yes, the transmission torque of the first clutch 4 exceeds the initial torque of the damper mechanism 41, so the process ends without executing the processing of this flowchart.

  When the determination in step S <b> 1 is No, the transmission torque of the first clutch 4 due to the target drive torque of the engine 1 or the power generation torque of the motor generator 2 is less than the initial torque of the damper mechanism 41. In this case, in order to prevent the generation of abnormal noise in the first clutch 4, the following processing is executed.

  The integrated controller 20 determines whether or not the battery 9 can be charged (step S2).

  Whether or not the battery 9 can be charged is determined by, for example, the SOC of the battery 9. When the SOC of the battery 9 is sufficiently large, the battery 9 cannot be charged for protection. Further, when the motor generator 2 is driving in the motor assist travel mode, the motor generator 2 cannot generate power.

  In such a state, since the power generation torque of the motor generator 2 cannot be increased by the process described below, the process ends without executing the process of this flowchart.

  If it is determined that the battery 9 can be charged, the process proceeds to step S3, and the integrated controller 20 generates power so that the power generation torque in the motor generator 2 exceeds the initial torque of the damper mechanism 41 of the first clutch 4. Increase torque.

  The increase in the power generation torque sets, for example, a lower limit value for the power generation amount of the motor generator 2. The integrated controller 20 performs control so as to maintain the power generation amount of the motor generator 2 so as not to fall below this lower limit value.

  By this control, the power generation torque of the motor generator 2 is maintained without falling below a predetermined value, so the power generation torque input to the motor generator 2, that is, the transmission torque of the first clutch 4 is lower than the initial torque of the damper mechanism 41. It is controlled so that there is nothing. As a result, the generation of abnormal noise in the first clutch 4 is prevented.

  As described above, the embodiment of the present invention travels by the driving force of the driving source including the engine 1 or the motor generator 2 and operates the motor generator 2 as a generator by the driving force of the engine or the regenerative power of the vehicle. In the hybrid vehicle capable of storing the electric power in No. 9, generation of abnormal noise in the first clutch 4 can be prevented.

  Specifically, when the transmission torque of the first clutch 4 provided between the engine 1 and the motor generator 2 is lower than the initial torque of the spring of the damper mechanism 41, the power generation amount of the motor generator 2 is increased. Note that the transmission torque of the first clutch 4 is determined by the target drive torque of the engine 1 or the power generation torque of the motor generator 2.

  Thereby, the noise and vibration in the 1st clutch 4 which generate | occur | produce when a damper function does not act because the transmission torque of the 1st clutch 4 is less than the initial torque of the spring of the damper mechanism 41 can be prevented.

  Further, since the power generation amount is increased by setting a lower limit value of the power generation amount of the motor generator 2, it is possible to prevent abnormal noise and vibration in the first clutch 4 without adding a physical configuration.

  Further, in a state where the SOC of the battery is close to full charge or in a state where the motor generator 2 is driven by the power of the battery, the amount of power generation is not increased, so that the battery 9 can be protected from overcharging and the like.

  Further, when the traveling mode is the WSC mode or when the accelerator opening APO is small, it is determined that the transmission torque of the first clutch 4 is lower than the initial torque of the spring of the damper mechanism 41, so that the damper function does not work. Therefore, it is possible to prevent abnormal noise and vibration in the first clutch 4 generated by the above.

DESCRIPTION OF SYMBOLS 1 Engine 2 Motor generator 4 1st clutch 5 2nd clutch 20 Integrated controller 41 Damper mechanism

Claims (5)

In a hybrid vehicle that travels by the driving force of an engine or a motor generator and operates the motor generator as a generator and can be stored in a battery, the control device controls the operation of the engine and the motor generator,
The hybrid vehicle includes a first clutch provided between the engine and the motor generator and capable of intermittently driving the engine, and a transmission torque of the first clutch provided in the first clutch. A damper mechanism capable of damping,
When the target drive torque of the engine or the power generation torque of the motor generator is smaller than the initial torque of the damper mechanism, the power generation amount of the motor generator is increased, and the power generation torque of the motor generator reduces the initial torque. A control apparatus for a hybrid vehicle, comprising power generation amount increasing means for controlling the power generation amount to exceed.   2. The hybrid vehicle control device according to claim 1, wherein the power generation amount increasing unit sets a lower limit value of the power generation amount of the motor generator to increase the power generation amount of the motor generator. 3.   The power generation amount increasing means prohibits an increase in the power generation amount of the motor generator when the SOC of the battery is substantially fully charged or when charging of the battery is prohibited. Item 3. The hybrid vehicle control device according to Item 2. The hybrid vehicle is provided with a second clutch between the engine and the motor generator and drive wheels,
The power generation amount increasing means increases the power generation amount of the motor generator in a WSC traveling state in which the vehicle travels while controlling the torque capacity of the second clutch. The control apparatus of the hybrid vehicle as described in one.   The power generation amount increasing means increases the power generation amount of the motor generator when the accelerator opening is smaller than a predetermined target drive torque determination opening. The control apparatus of the hybrid vehicle as described in one.

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