JP5338473B2 - Engine start control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine starting control device capable of starting an engine without lengthening a starting time even in cold starting, and also advantageous in terms of cost and weight. <P>SOLUTION: This engine starting control device includes an integral controller 10 for driving a motor generator MG when starting the engine and performing starting control for starting by enhancing an engine speed up to an initial explosion engine target speed Ne* by fastening a first clutch CL1, and is characterized in that the integral controller 10 sets a motor target rotating speed Nm* high by comparing with a relatively high case when the battery temperature Temp-bat detected by a battery temperature sensor 32 is relatively low when performing the starting control. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an engine start control device suitable for application to a hybrid vehicle, and more particularly to a cold start technology.

Conventionally, a hybrid vehicle is known in which a motor is interposed in a drive transmission path that connects an engine and driving wheels, and a clutch that connects and disconnects the two is interposed between the engine and the motor.
In such a conventional hybrid vehicle, a clutch is engaged and motor torque is distributed to the engine side to start the engine.

  Further, in such a hybrid vehicle, in order to prevent the battery output from decreasing at low temperatures and preventing the motor output for starting the engine from being secured, the electric heater is operated and the engine is heated to start the engine. For example, Japanese Patent Application Laid-Open No. H10-133260 discloses a device that improves the ease and reduces the required motor output.

JP 2003-227366 A

  However, the conventional engine start control device described above is configured to start the engine after the temperature of the engine is raised with an electric heater. Therefore, it takes time until the temperature of the engine is raised, and it takes time to start the engine. Had a problem. Furthermore, an electric heater is necessary, and there is a problem in that the cost and weight are increased accordingly.

  The present invention has been made paying attention to the above-mentioned problems, and provides an engine start control device that enables engine start without increasing the start time even during cold start, and that is advantageous in terms of cost and weight. The purpose is to do.

  In order to achieve the above object, an engine start control device of the present invention drives a motor at the time of engine start and also engages a clutch interposed between the motor and the engine to set the engine speed to a target start speed. Control means for performing start-up control to increase the number to start, the control means, when performing the start-up control, when the detection temperature of the temperature detection means is relatively low, compared to the case of relatively high, The engine start control device is characterized in that the motor target rotational speed is set high.

  In the engine start control device of the present invention, when the engine is started, the control means executes the start control, drives the motor, engages the clutch, transmits the rotation of the motor to the engine, and starts the engine speed. When the target speed is exceeded, the engine is started.

  During this starting control, the control means sets the motor target rotational speed higher when the detected temperature of the drive system including the battery detected by the temperature detection means is relatively low as compared to when the temperature is relatively high.

Thus, since the motor target rotational speed is controlled to be relatively high, even if the battery is low in temperature and the motor output is reduced, this insufficient torque is compensated for and the motor target rotational speed is not controlled to be relatively high. Compared to the case, the engine speed can be increased, and the engine can be started in a shorter time than that using a heater.
Moreover, since it is possible to start the engine in the cold state based on the control as described above, it is possible to achieve the engine start at a low temperature at a lower cost compared to a configuration in which a heater or the like is added. .

1 is an overall system diagram illustrating an example of a rear-wheel drive hybrid vehicle to which an engine start control device of Embodiment 1 is applied. It is a control block diagram which shows the arithmetic processing performed in the integrated controller 10 of FR hybrid vehicle to which the engine starting control apparatus of Example 1 was applied. It is a figure which shows the EV-HEV selection map used when performing the mode selection process in the integrated controller 10 of FR hybrid vehicle to which the engine starting control apparatus of Example 1 is applied. It is a figure which shows the target charge / discharge amount map used when battery charge control is performed by the integrated controller 10 of the FR hybrid vehicle to which the engine start control device of the first embodiment is applied. 3 is a flowchart showing a flow of processing executed by the integrated controller 10 applied to the engine start control device of the first embodiment. 3 is a flowchart showing a flow of processing of engine start control executed by an integrated controller 10 applied to the engine start control device of Embodiment 1; It is a figure which shows the first-explosion rotation speed map used for the setting of the first-explosion engine target rotation speed Ne * in the integrated controller 10 applied to the engine start control device of the first embodiment. It is a figure which shows the engine starting torque map used for the setting of the starting clutch torque capacity | capacitance TCL1 in the integrated controller 10 applied to the engine starting control apparatus of Example 1. FIG. It is a figure which shows the engine starting clutch oil pressure map used for the setting of the clutch torque capacity command value CL1 * at the time of starting in the integrated controller 10 applied to the engine starting control apparatus of Example 1. FIG. It is a figure which shows the line pressure map used for the setting of line pressure PL in the integrated controller 10 applied to the engine starting control apparatus of Example 1. FIG. It is a figure which shows the motor axis friction map used for the setting of the motor axis friction Tfric in the integrated controller 10 applied to the engine starting control apparatus of Example 1. FIG. It is a figure which shows the motor output torque map used for the setting of motor output possible torque Tm_max in the integrated controller 10 applied to the engine starting control apparatus of Example 1. FIG. It is a figure which shows the fastening subtraction value map used for the setting of the fastening subtraction value (alpha) in the integrated controller 10 applied to the engine starting control apparatus of Example 1. FIG. It is a figure which shows the clutch torque capacity command value map at the time of an engagement used for the setting of the torque capacity subtraction value (beta) at the time of engagement in the integrated controller 10 applied to the engine starting control apparatus of Example 1. 3 is a time chart illustrating an operation example of the engine start control device according to the first embodiment. It is an effect explanatory view explaining an operation of the engine starting control device of Example 1.

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

 A clutch control device according to an embodiment of the present invention includes a clutch (CL1) that is interposed between an engine (Eng) and an engine start motor (MG) and can change a transmission torque capacity, and the motor (MG). ) And temperature detecting means (18a, 31, 32) for detecting the temperature related to the driving system including the battery (4) for supplying electric power, and the motor (MG) is driven when the engine (Eng) is started. And control means (10) for starting the clutch (CL1) and starting the engine (Eng) by increasing the rotation speed of the engine (Eng) to a start target rotation speed (Ne *), When the detected temperature of the temperature detecting means (18a, 31, 32) is relatively low during execution of the start control, the control means (10) is a motor compared to a relatively high temperature. An engine start control system and sets target rotational speed (Nm *) high.

  A clutch control apparatus according to Embodiment 1 of the best mode for carrying out the invention will be described with reference to FIGS.

First, the configuration of the first embodiment will be described.
FIG. 1 is an overall system diagram showing a rear-wheel drive hybrid vehicle (an example of a hybrid vehicle) to which the engine start control device of the first embodiment is applied. Based on this diagram, the configuration of a drive system and a control system is shown. explain.

(Drive system in Example 1)
First, the configuration of the drive system will be described.
The drive system of the FR hybrid vehicle in the first embodiment includes an engine Eng, a flywheel FW, a first clutch CL1, a motor generator MG, a second clutch CL2, an automatic transmission AT, a propeller shaft PS, and a differential. It has DF, left drive shaft DSL, right drive shaft DSR, left rear wheel RL, and right rear wheel RR. Note that FL is the left front wheel and FR is the right front wheel.

  The engine Eng is a gasoline engine or a diesel engine. Based on an engine control command from the engine controller 1, engine start control, engine stop control, throttle valve opening control, fuel cut control, and the like are performed. The engine output shaft is provided with a flywheel FW.

  The first clutch CL1 is a clutch interposed between the engine Eng and the motor generator MG, and is generated by the first clutch hydraulic unit 6 based on a first clutch control command from the first clutch controller 5. The first clutch control hydraulic pressure controls engagement / slip engagement (half-clutch state) / release.

  As such a first clutch CL1, for example, a normally closed state in which a complete engagement is maintained by an urging force of a diaphragm spring and a stroke control using a hydraulic actuator 14 having a piston 14a is controlled from a slip engagement to a complete release. Can be used. Alternatively, a normally closed wet multi-plate clutch or wet multi-plate brake that can continuously control the oil flow rate and hydraulic pressure with a proportional solenoid can be used.

  The motor generator MG is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, and a three-phase alternating current generated by an inverter 3 is applied based on a control command from the motor controller 2. It is controlled by doing. The motor generator MG can also operate as an electric motor that is driven to rotate by receiving power supplied from the battery 4 (this operation state is referred to as “powering” in this specification), and the rotor is driven by the engine Eng or the drive. When receiving rotational energy from the wheel, it functions as a generator that generates electromotive force at both ends of the stator coil, and can also charge the battery 4 (this operation state is referred to as “regeneration” in this specification). . The rotor of motor generator MG is connected to the transmission input shaft of automatic transmission AT via a damper.

  The second clutch CL2 is a clutch interposed between the motor generator MG and the left and right rear wheels RL, RR, and based on a second clutch control command from the AT controller 7, the second clutch hydraulic unit 8 The fastening / slip fastening / release is controlled by the control hydraulic pressure generated by the above. As the second clutch CL2, for example, a normally open wet multi-plate clutch or a wet multi-plate brake capable of continuously controlling the oil flow rate and hydraulic pressure with a proportional solenoid is used. The first clutch hydraulic unit 6 and the second clutch hydraulic unit 8 are built in an AT hydraulic control valve unit CVU attached to the automatic transmission AT.

  The automatic transmission AT is, for example, a stepped transmission that automatically switches stepped speeds such as forward 7 speed / reverse 1 speed according to vehicle speed, accelerator opening, etc., and the second clutch CL2 However, it is not newly added as a dedicated clutch, but the most suitable clutch or brake arranged in the torque transmission path is selected from among a plurality of friction engagement elements that are engaged at each gear stage of the automatic transmission AT. . The output shaft of the automatic transmission AT is connected to the left and right rear wheels RL and RR via a propeller shaft PS, a differential DF, a left drive shaft DSL, and a right drive shaft DSR.

  The hybrid drive system of the first embodiment includes an electric vehicle travel mode (hereinafter referred to as “EV mode”), a hybrid vehicle travel mode (hereinafter referred to as “HEV mode”), and a drive torque control travel mode (hereinafter referred to as “ It has a travel mode such as “WSC mode”.

  The “EV mode” is a mode in which the first clutch CL1 is disengaged and the vehicle travels only with the power of the motor generator MG. The “HEV mode” is a mode in which the first clutch CL1 is engaged and the vehicle travels in any of the motor assist travel mode, travel power generation mode, and engine travel mode. The “WSC mode” is the second by controlling the rotation speed of the motor generator MG at the time of P, N → D select start from the “HEV mode”, or at the start of the D range from the “EV mode” or “HEV mode”. In this mode, the clutch CL2 is maintained in the slip engagement state, and the clutch transmission torque that passes through the second clutch CL2 starts while controlling the clutch torque capacity so that the required driving torque is determined according to the vehicle state and the driver operation. . “WSC” is an abbreviation for “Wet Start Clutch”.

(Control system in Example 1)
Next, the control system of the hybrid vehicle will be described.
As shown in FIG. 1, the control system of the FR hybrid vehicle in the first embodiment includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a first clutch controller 5, and a first clutch hydraulic unit 6. And an AT controller 7, a second clutch hydraulic unit 8, a brake controller 9, and an integrated controller 10. The engine controller 1, the motor controller 2, the first clutch controller 5, the AT controller 7, the brake controller 9, and the integrated controller 10 are connected via a CAN communication line 11 that can mutually exchange information. ing.

  The engine controller 1 inputs engine speed information from the engine speed sensor 12, a target engine torque (tTe) command from the integrated controller 10, and other necessary information. Then, a command for controlling the engine operating point (Ne, Te) is output to the throttle valve actuator or the like of the engine Eng. The other necessary information includes the engine oil temperature Temp-e detected by the engine oil temperature sensor 31.

  The motor controller 2 includes information from the resolver 13 that detects the rotor rotational position of the motor generator MG, a target motor torque command and a target motor rotational speed command from the integrated controller 10, and a battery temperature detected by the battery temperature sensor 32. Input other necessary information including Temp-bat. Then, a command (tNm, tTm) for controlling the motor operating point (Nm, Tm) of motor generator MG is output to inverter 3. The motor controller 2 monitors the battery charge amount SOC indicating the charge capacity of the battery 4, and this battery charge amount SOC information is used for control information of the motor generator MG and via the CAN communication line 11. To the integrated controller 10.

  The first clutch controller 5 includes sensor information from the first clutch stroke sensor 15 that detects the stroke position of the piston 14a of the hydraulic actuator 14, a target first clutch torque capacity command from the integrated controller 10, and other necessary information. Enter. Then, a command for controlling engagement / slip engagement / release of the first clutch CL1 is output to the first clutch hydraulic unit 6 in the AT hydraulic control valve unit CVU.

  The AT controller 7 includes other sensors 18 (transmission) including an accelerator opening sensor 16, a vehicle speed sensor 17, and an ATF temperature sensor 18a for detecting the temperature of lubricating oil (hereinafter referred to as ATF) of the automatic transmission AT. Input information from the input speed sensor, inhibitor switch, etc. Then, when traveling with the D range selected, a control command for retrieving the optimum gear position by searching for the position where the operating point determined by the accelerator opening APO and the vehicle speed VSP exists on the shift map is obtained. Output to AT hydraulic control valve unit CVU. The shift map is a map in which an upshift line and a downshift line are written according to the accelerator opening and the vehicle speed. In addition to the automatic shift control, when a target second clutch torque capacity command is input from the integrated controller 10, a command for controlling the slip engagement of the second clutch CL2 is sent to the second clutch hydraulic unit 8 in the AT hydraulic control valve unit CVU. 2nd clutch control which outputs to is performed. When the shift control change command is output from the integrated controller 10, the shift control according to the shift control change command is performed instead of the shift control normally.

  The brake controller 9 inputs a wheel speed sensor 19 for detecting the wheel speeds of the four wheels, sensor information from the brake stroke sensor 20, a regenerative cooperative control command from the integrated controller 10, and other necessary information. And, for example, at the time of brake depression, if the regenerative braking force is insufficient for the required braking force obtained from the brake stroke BS, the shortage is compensated by the mechanical braking force (hydraulic braking force or motor braking force) Perform regenerative cooperative brake control.

  The integrated controller 10 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. The motor rotation number sensor 21 for detecting the motor rotation number Nm and other sensors / switches 22 are used. Necessary information and information via the CAN communication line 11 are input. Then, a target engine torque (tTe) command is sent to the engine controller 1, a target motor torque command and a target motor speed command are sent to the motor controller 2, a target first clutch torque capacity command is sent to the first clutch controller 5, and a target second value is sent to the AT controller 7. A clutch torque capacity command and a regenerative cooperative control command are output to the brake controller 9.

  FIG. 2 is a control block diagram illustrating arithmetic processing executed by the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. FIG. 3 is a diagram showing an EV-HEV selection map used when mode selection processing is performed in the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. FIG. 4 is a diagram illustrating a target charge / discharge amount map used when battery charge control is performed by the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. Hereinafter, based on FIGS. 2-4, the arithmetic processing performed in the integrated controller 10 of Example 1 is demonstrated.

  As shown in FIG. 2, the integrated controller 10 includes a target drive torque calculator 100, a mode selector 200, a target charge / discharge calculator 300, and an operating point command unit 400.

  The target drive torque calculator 100 calculates the target drive torque tFo0 from the accelerator opening APO and the vehicle speed VSP using the target drive torque map.

  The mode selection unit 200 selects “EV mode” or “HEV mode” as the target travel mode from the accelerator opening APO and the vehicle speed VSP using the EV-HEV selection map shown in FIG. 3. However, if the battery charge SOC is equal to or less than the predetermined value, the “HEV mode” is forcibly set as the target travel mode. Further, at the time of P, N → D select start from the “HEV mode”, the “WSC mode” is selected as the target travel mode until the vehicle speed VSP becomes the first set vehicle speed VSP1.

  The target charge / discharge calculation unit 300 calculates the target charge / discharge power tP from the battery charge amount SOC using the target charge / discharge amount map shown in FIG.

  In the operating point command unit 400, based on input information such as the accelerator opening APO, the target driving torque tFo0, the target travel mode, the vehicle speed VSP, the target charge / discharge power tP, etc., the target engine torque is set as the operating point reaching target. , Target motor torque, target motor speed tNm, target first clutch torque capacity tTc1, and target second clutch torque capacity tTc2. Then, a target engine torque (tTe) command, a target motor torque (tTm) command, a target motor rotation speed (tNm) command, a target first clutch torque capacity (tTc1) command, and a target second clutch torque capacity (tTc2) command, The data is output to each of the controllers 1, 2, 5, and 7 via the CAN communication line 11.

(Control executed by the integrated controller 10)
Next, the contents of the control executed by the integrated controller 10 of the first embodiment will be described based on the flowchart of FIG.
First, in step S1, a steady target drive torque tFo0 is calculated from the accelerator opening APO and the vehicle speed VSP using a preset target drive torque map, and the process proceeds to the next step S2.

  In step S2, the target shift speed SHIFT is calculated from the accelerator opening APO and the vehicle speed VSP based on a preset shift map, and the process proceeds to the next step S3.

  In step S3, a target operation mode (EV mode, HEV mode, WSC mode) is determined from the accelerator opening APO and the vehicle speed VSP using a preset target operation mode region map (see FIG. 3). The process proceeds to step S4. In step S3, as shown in FIG. 3, normally, the HEV mode is set at a high load (large accelerator opening) and a high vehicle speed, and the EV mode is set at a low load and a low vehicle speed.

In step S4, an operation mode transition calculation is performed by comparing the current operation mode with the target operation mode, and the process proceeds to the next step S5.
In step S4, if the current operation mode matches the target operation mode, the current operation mode is maintained. Further, if the current operation mode is the EV mode and the target operation mode is the HEV mode, a command to switch the mode from the EV mode to the HEV mode is issued. On the other hand, if the current operation mode is the HEV mode and the target operation mode is the EV mode, the mode switching from the HEV mode to the EV mode is instructed.

  In step S5, a transient target drive torque tFo required to shift from the current drive force to the target drive torque tFo0 obtained in step S1 with a response having a predetermined seasoning is calculated, and the process proceeds to step S6. In the calculation of step S5, for example, an output obtained by passing the target drive torque tFo0 through a low-pass filter having a predetermined time constant can be set as the transient target drive torque tFo.

In step S6, the target engine torque tTe required to achieve the transient target drive torque tFo is obtained in cooperation with the motor generator MG or alone, and the process proceeds to step S7.
The target engine torque tTe depends on the operation mode (EV mode, HEV mode) and mode switching, the transient target drive torque tFo, the tire effective radius Rt of the left and right rear wheels RL and RR, and the final gear ratio if. , Obtained from the gear ratio iG of the automatic transmission AT determined by the currently selected shift speed, the input rotational speed Ni of the automatic transmission AT, the engine rotational speed Ne, and the target charge / discharge power tP according to the battery charge amount SOC. .

  In step S7, the target first clutch torque capacity tTc1 and the target second clutch necessary for achieving the transient target drive torque tFo or necessary for executing the mode transition according to the operation mode and the mode transition. The torque capacity tTc2 is calculated, and the process proceeds to the next step S8.

  In step S8, the target motor torque tTm necessary for achieving the transient target drive torque tFo, or the target motor rotation speed tNm as required, is obtained in cooperation with the engine Eng or alone, and the process proceeds to the next step S9. move on. Note that the target motor torque tTm depends on the transient target drive torque tFo, the effective tire radius Rt of the left and right rear wheels RL and RR, the final gear ratio if, and the currently selected shift speed, depending on the operation mode and mode switching. It is obtained from the determined gear ratio iG of the automatic transmission AT, the input rotational speed Ni of the automatic transmission AT, the engine rotational speed Ne, and the target charge / discharge power tP according to the battery charge amount SOC. Further, the target motor rotation speed tNm is calculated in place of the target motor torque tTm at the time of engine start described later.

  In step S9, the command values for achieving the target gear stage SHIFT, the operation mode holding or switching command, the target engine torque tTe, the both clutch torque capacities tTc1 and tTc2, the target motor torque tTm, and the target motor rotation speed tNm are obtained. , 2, 5 and 7.

(Engine start control)
When the integrated controller 10 shifts from the EV mode including the stop state to the HEV mode, the engine start control is executed to start the engine Eng.
The engine start control will be described based on the flowchart of FIG.

  In this engine start control, first, in step S21, it is determined whether or not an engine start request has occurred. If there is an engine start request, the process proceeds to step S22, and if there is no engine start request, engine start processing is executed. One process is terminated without any processing.

  This engine start request is generated when the shift from the EV mode to the HEV mode is determined in the operation mode transition determination at the above-described step S4 as the accelerator opening APO and the vehicle speed VSP increase. That is, in the first embodiment, as shown in FIG. 3, in the start and the low vehicle speed range, the vehicle is driven in the EV mode, and the vehicle speed VSP or the accelerator opening APO exceeds the EV⇒HEV switching line. At that time, the engine Eng is started and shifts to the HEV mode.

  In step S22, parameters are read and the process proceeds to step S23. The parameters include battery temperature Temp-bat, engine oil temperature Temp-e, and ATF temperature Temp-atf.

  In step S23, an initial explosion engine target rotational speed Ne (starting target rotational speed) Ne * that is an engine rotational speed Ne required for the initial explosion is set, and the process proceeds to step S24. As shown in FIG. 7, the initial explosion engine target speed Ne * is set based on the engine oil temperature Temp-e, and is set to a higher speed as the engine oil temperature Temp-e becomes lower. The

In step S24, the starting clutch torque capacity TCL1, which is the transmission torque of the first clutch CL1 required for the first explosion, is set, and the process proceeds to step S25.
The starting clutch torque capacity TCL1 is obtained based on the engine starting torque map shown in FIG. 8 to obtain the engine starting torque corresponding to the initial explosion engine target rotational speed Ne *, and this engine starting torque is determined as the starting clutch torque. Set as capacitance TCL1. Further, as shown in FIG. 8, the engine starting torque and the starting clutch torque capacity TCL1 are set larger as the initial explosion engine target rotational speed Ne * is higher in accordance with the initial explosion engine target rotational speed Ne *. In accordance with the engine oil temperature Temp-e, the lower the engine oil temperature Temp-e, the higher the value is set.

In step S25, the starting clutch torque capacity command value CL1 * of the first clutch CL1 required for the first explosion is set, and the process proceeds to step S26. The starting clutch torque capacity command value CL1 * is set in proportion to the starting clutch torque capacity TCL1, and the ATF temperature Temp-atf is low, as shown in the starting clutch torque capacity map shown in FIG. The higher the engine friction, the higher the value is set.
The starting clutch torque capacity command value CL1 * is the minimum hydraulic pressure that can convert the engine friction into the hydraulic pressure and increase the engine speed.

  In step S26, the line pressure PL necessary to obtain the starting clutch torque capacity command value CL1 * is set, and the process proceeds to step S27. As shown in the line pressure map of FIG. 10, the line pressure PL is set in proportion to the starting clutch torque capacity command value CL1 *, and is set to shift higher as the ATF temperature Temp-atf is higher. The

  In step S27, the motor shaft friction Tfric is set, and the process proceeds to step S28. This motor shaft friction Tfric corresponds to the transmission torque of the drive system, and is set in proportion to the line pressure PL as shown in the motor shaft friction map of FIG. 11, and also according to the ATF temperature Temp-atf. The lower the ATF temperature Temp-atf, the lower the setting.

  In step S28, motor output possible torque Tm_max is calculated, and the process proceeds to step S29. As shown in the motor output possible torque map in FIG. 12, a plurality of maps are set for the motor output possible torque Tm_max in accordance with the battery charge amount SOC. In each map, the motor output possible torque Tm_max is set higher as the motor rotation speed Nm is lower according to the motor rotation speed Nm, and is shifted higher as the battery temperature Temp-bat is higher according to the battery temperature Temp-bat. Is set. Further, in the plurality of maps, the motor output possible torque Tm_max is set lower as the battery charge amount SOC is lower.

  In step S29, whether the motor output possible torque Tm_max is equal to or smaller than the value obtained by adding the on-motor clutch friction capacity TCL1 to the starting clutch torque capacity TCL1, that is, the engine can be started while obtaining a necessary driving torque. If it is equal to or smaller than this value, the process proceeds to step S30. If it is not smaller than this value, the process proceeds to step S33.

  In step S30, the motor target rotational speed Nm * necessary for the first explosion is set, and the process proceeds to step S31. Motor target rotation speed Nm * is set to a higher value so that rotation energy that can compensate for motor torque shortage can be obtained as battery temperature Temp_bat becomes lower. In the first embodiment, the motor target rotational speed Nm * is set based on the motor output possible torque Tm_max (see FIG. 12) set according to the battery temperature Temp_bat, and further, the engine inertia, the initial explosion engine target The calculation is performed with the rotational speed Ne * (see FIG. 7) and the motor inertia taken into account.

In step S31, the motor rotation speed Nm is increased toward the motor target rotation speed Nm *, and the process proceeds to step S32.
In step S32, it is determined whether or not the motor rotation speed Nm is equal to or greater than the engagement start rotation speed Nmst obtained by subtracting the engagement subtraction value α from the motor target rotation speed Nm *. Proceeding to S33, if it is not equal to or greater than the fastening start rotational speed Nmst, step S32 is repeated.
As shown in FIG. 13, the engagement subtraction value α is set to a larger value as the ATF temperature Temp-atf is lower according to the ATF temperature Temp-atf.

  In step S33, torque capacity control for controlling the first clutch CL1 toward the starting clutch torque capacity TCL1 is started, and the process proceeds to step S34. The starting clutch torque capacity TCL1 is lower than the engagement hydraulic pressure CL2 *, which is the clutch torque capacity when the first clutch CL1 is completely engaged, and as described above, the engine rotation speed is increased. It is set to a possible value.

  In step S34, it is determined whether or not the engine speed Ne is equal to or higher than the engagement rotation speed Netei obtained by subtracting the engagement torque capacity subtraction value β from the initial explosion engine target rotation speed Ne *. If this is the case, the process proceeds to step S35, and if it is not equal to or greater than the fastening rotational speed Netei, the process proceeds to step S36.

In step S35, a clutch torque capacity command at the time of engagement that forms an engagement hydraulic pressure CL2 * for completely engaging the first clutch CL1 is output and completely engaged.
In addition, as shown in FIG. 14, the torque capacity subtraction value β at the time of engagement is set to a larger value as the ATF temperature Temp-atf is lower, according to the ATF temperature Temp-atf.
In step S36, the torque capacity of the first clutch CL1 is increased, and the process returns to step S34.

(Operation of Example 1)
Next, the operation of the first embodiment will be described separately for the battery temperature Temp-bat.

(When battery is not cold)
When the battery temperature Temp-bat is sufficiently high, the value of the motor output possible torque Tm_max calculated in step S28 is also a sufficiently high value as compared with the low temperature of the battery. Therefore, NO is determined in step S29. . In this case, the engine Eng can be started only by executing the first clutch torque capacity control for the first clutch CL1 and distributing the torque of the motor generator MG driven at that time to the engine Eng side.

(When battery is cold)
When the battery temperature Temp-bat is low, the motor output possible torque Tm_max is equal to or less than the sum of the starting clutch torque capacity TCL1 and the motor generator shaft friction Tfric when the engine is started, and the necessary motor torque is reduced to the motor output possible torque. There is a case where it falls below Tm_nax.

In this case, based on the processing in step S30, the motor generator target rotational speed Nm * is set higher as the temperature becomes lower.
The operation in this case will be described based on the time chart of FIG.
In the example shown in this time chart, a start request is generated at time t1, and the motor rotation speed Nm is increased toward the motor target rotation speed Nm * based on the start request, and the motor rotation speed Nm As the motor torque increases, the motor torque Tm also increases (based on steps S29 → S30 → S31).

Thereafter, when the motor rotation speed Nm exceeds the engagement start rotation speed Nmst obtained by subtracting the engagement subtraction value α from the motor target rotation speed Nm * (t2), torque capacity control of the first clutch CL1 is started (steps S32 → S33). ), The starting clutch torque capacity command value CL1 * is output toward the first clutch CL1.
Since the engagement subtraction value α is set to a larger value as the ATF temperature Temp-atf is lower in accordance with the hydraulic response, the battery power is wasted in order to maintain the motor rotation speed Nm due to a delay in the hydraulic response. Is suppressed.

  By the torque capacity control of the first clutch CL1, the torque capacity of the first clutch CL1 rises at time t3 and is transmitted to the engine Eng, and the engine speed Ne starts to increase.

Then, at time t4 when the engine speed Ne reaches the engagement rotation speed Netei obtained by subtracting the engagement torque capacity subtraction value β from the initial explosion engine target rotation speed Ne *, the first clutch CL1 is to be fully engaged. The clutch torque capacity command at the time of engagement that forms the engagement hydraulic pressure CL2 * is output (step S34 → S35).
As a result, the engine speed Ne further increases, and at time t5 when the initial explosion engine target speed Ne * is reached, the engine Eng is started and engine torque Te is generated.

  The engagement torque capacity subtraction value β that determines the engagement rotational speed Netei is set to a larger value as the ATF temperature Temp-atf is lower, and slippage occurs in the first clutch CL1 due to a hydraulic response delay, and the engine start start timing is delayed. Can be prevented.

(Effect of Example 1)
As described above, the effects listed below can be obtained in the first embodiment.
a) When the motor output possible torque Tm_max is equal to or less than the sum of the drive torque (motor shaft friction Tfric) and the torque required for engine start (TCL1), the motor target rotational speed Nm * at engine start is According to the battery temperature Temp-bat, the lower the battery temperature Temp-bat, the higher the rotation speed is set. Therefore, as a result of the motor rotation speed Nm at the start of the engine being higher than that at the time when the battery is hot, the torque transmitted to the engine Eng is increased, and the engine start at a low temperature is compensated for torque shortage. Possible.

In other words, the output of battery 4 is limited as the temperature decreases, and as a result, the output that motor generator MG can output is limited. In this case, as shown in FIG. 16, the motor output possible torque obtained when the motor target rotational speed Nm * is used is the clutch transmission torque (startup clutch torque capacity TCL1) required to start the engine Eng. The value may be smaller than the value obtained by adding the driving torque (motor shaft friction Tfric) necessary to drive the vehicle.
In this case, the engine Eng cannot be started due to insufficient motor torque.

  On the other hand, in the first embodiment, when the battery temperature is low, the motor target rotational speed Nm * is set high, so that the torque that can be output from the motor is increased to compensate for the shortage of the motor torque, and the engine Eng can be started. Become.

  b) As described above in a), when the engine can be started, the motor rotation speed Nm is simply increased. Therefore, compared with the case where the engine Eng is warmed by a heater or the like, The time required can be shortened, and it is advantageous in terms of cost and weight as compared with a heater added.

c) As the temperature of the ATF temperature Temp-atf is lower, the engagement subtraction value α is set larger and the engagement start rotation speed Nmst is set smaller, so that the engagement start timing of the first clutch CL1 is advanced.
Therefore, even if a response delay occurs in the first clutch CL1 due to the low temperature, the response delay can be suppressed by the amount that the output timing of the clutch engagement command is advanced. As a result, the idling rotation time of the motor generator MG caused by the engagement delay of the first clutch CL1 is shortened, and the wasteful rotation time of the motor generator MG can be shortened to efficiently start the engine Eng. Become.

d) In order to obtain the effect of the above c), the start clutch torque capacity TCL1 is advanced by increasing the engagement subtraction value α as the temperature of the ATF temperature Temp-atf is lower. Therefore, the command output timing of the starting clutch torque capacity TCL1 can be easily set optimally according to the change in the motor target rotational speed Nm *.
In addition, as the clutch engagement command, first, since the clutch torque capacity TCL1 at the time of start that is lower than the clutch torque capacity at the time of engagement is output, the torque capacity is excessive as compared with the case of outputting the command of the clutch torque capacity at the time of engagement from the beginning. Thus, it is possible to suppress the occurrence of a phenomenon in which the motor rotation speed Nm rapidly decreases, and to improve engine startability.

e) The starting clutch torque capacity command value CL1 * commanded to the first clutch CL1 required for the first explosion is obtained by converting engine friction, which becomes larger as the ATF temperature Temp-atf is lower, into hydraulic pressure, and sliding the engine Eng. The hydraulic pressure is such that the lowest possible torque capacity is obtained.
As a result, it is possible to further suppress a sudden decrease in the motor rotation speed Nm due to excessive torque capacity, and to further improve engine startability.

f) The engagement torque capacity subtraction value β used to calculate the engagement rotation speed Netei, which is the engine rotation speed Ne when the first clutch CL1 is engaged to start the engine Eng, has a low ATF temperature Temp-atf. I set it to be as large as possible.
As a result, when the ATF temperature Temp-atf is low, the command timing of the engagement hydraulic pressure CL2 * for completely engaging the first clutch CL1 is advanced, and an unexpected disturbance (for example, the initial explosion torque of the engine Eng For example, it is possible to avoid slippage in the first clutch CL1 and to suppress deterioration of the first clutch CL1 due to slippage.

  g) In order to speed up the command output timing of the engagement hydraulic pressure CL2 * in order to obtain the effect of f), the lower the ATF temperature Temp-atf, the larger the engagement torque capacity subtraction value β is set. Therefore, the command output timing of the fastening hydraulic pressure CL2 * can be easily set optimally according to the change in the initial explosion engine target speed Ne *.

  As mentioned above, although the clutch control apparatus of this invention has been demonstrated based on Embodiment and Example 1, a specific structure is not restricted to these Examples, Each claim of a claim is a claim. Design changes and additions are allowed without departing from the gist of the invention.

  For example, in Example 1, although the example applied to FR hybrid vehicle was shown, the control apparatus of this invention is applicable also to FF hybrid vehicle, for example.

In the first embodiment, the motor generator MG used for driving the driving wheels is shown as the motor. However, a motor dedicated to starting the engine can also be used.
Further, even when a motor for driving the drive wheels is used as the motor, the motor generator MG that can perform power running and regeneration as shown in the first embodiment is not limited to the motor generator MG, and a motor capable of only power running may be used. .

  Further, in the first embodiment, an example in which the battery temperature detected by the battery temperature sensor 32 is used as the detection temperature used for executing the process of setting the motor target rotational speed high when the detection temperature is low during start control. As shown, if the battery temperature can be estimated, the ATF temperature Temp-atf and the engine oil temperature Temp-e may be substituted. In this case, it is possible to reduce the cost by reducing the number of sensors. Can do.

  In addition, in executing the clutch engagement process in which the output timing of the clutch engagement command is relatively earlier as the detected temperature is lower, in Example 1, the motor rotation speed is subtracted from the motor target rotation speed. The clutch torque capacity command at the time of start is output at the time when the engagement start rotational speed minus the value is reached, and the engagement start subtraction value is relatively increased as the ATF temperature (detected temperature) Temp-atf is relatively lower. Increased the setting. However, the speed at which the clutch engagement command is output in this way is not limited to this, but the fastening start rotational speed is fixed, and the speed of increase in the motor rotational speed is increased according to the temperature. The following means may be used.

  Similarly, at the time of starting control execution, in order to advance the output timing of the clutch torque capacity command at the time of engagement as the detected temperature is relatively low, in Example 1, the torque capacity subtraction value β at the time of engagement is set to the ATF temperature Temp. However, the present invention is not limited to this. However, the engine rotational speed Ne is increased by increasing the speed of increase of the motor rotational speed Nm or increasing the starting clutch torque capacity command value CL1 *. May be increased so that the output timing of the clutch torque capacity command at the time of engagement is advanced.

4 battery 10 integrated controller (control means)
18a ATF temperature sensor (temperature detection means)
31 Engine oil temperature sensor (temperature detection means)
32 Battery temperature sensor (temperature detection means)
CL1 First clutch CL1 * Clutch torque capacity command value at start CL2 * Engagement hydraulic eng Engine MG Motor generator (motor)
Ne Engine speed Ne * Initial explosion engine target speed (starting target engine speed)
Nm Motor speed Nm * Motor target speed TCL1 Clutch torque capacity at startup Temp-atf ATF temperature Temp-bat Battery temperature Temp-e Engine oil temperature α Engagement subtraction value β Engagement torque capacity subtraction value

Claims (5)

A clutch interposed between the engine and the motor for starting the engine and capable of changing the transmission torque capacity;
Temperature detecting means for detecting the temperature of the battery for supplying power of the motor,
Control means for executing start control for starting the engine by driving the motor and fastening the clutch to increase the engine speed to a start target speed;
With
The control means sets the motor target rotational speed higher when the detection temperature of the temperature detection means is relatively low when the start control is executed, compared to a case where the temperature is relatively high. Engine start control device. A clutch interposed between the engine and the motor for starting the engine and capable of changing the transmission torque capacity;
Temperature detecting means for detecting a temperature related to a drive system including a battery for supplying electric power to the motor;
Control means for executing start control for starting the engine by driving the motor and fastening the clutch to increase the engine speed to a start target speed;
With
The control means performs a process of setting the motor target rotational speed higher when the detection temperature of the temperature detection means is relatively low when the start control is executed, compared to a case where the temperature is relatively high. , the detected as the temperature is relatively low, the clutch engagement command features and to Rue engine start control apparatus that executes the clutch engagement processing for relatively faster output timing. The control means, as the clutch engagement command, first outputs a start-time clutch torque capacity command that is a start-time clutch torque capacity that is lower than the engagement-time clutch torque capacity that makes the clutch fully engaged, When the engine speed increases to the set speed, a clutch torque capacity command at engagement is output as the clutch torque capacity at engagement.
The control means outputs the starting clutch torque capacity command when the motor speed reaches the engagement start rotation speed obtained by subtracting the engagement start subtraction value from the motor target rotation speed, and the engagement start subtraction The engine start control device according to claim 2, wherein the value is set to be relatively large as the detected temperature is relatively low.   4. The engine start control device according to claim 3, wherein the control means uses a torque capacity converted into engine friction obtained based on the detected temperature as the start-time clutch torque capacity command. A clutch interposed between the engine and the motor for starting the engine and capable of changing the transmission torque capacity;
Temperature detecting means for detecting a temperature related to a drive system including a battery for supplying electric power to the motor;
Control means for executing start control for starting the engine by driving the motor and fastening the clutch to increase the engine speed to a start target speed;
With
In the start control , the control means sets the motor target rotational speed higher when the detected temperature of the temperature detecting means is relatively lower than when the detected temperature is relatively high, and the detected temperature There as relatively low, the engagement when the clutch torque capacity command feature and to Rue engine start control device to quickly output timing.

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