JP6194735B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control apparatus for a hybrid vehicle including a motor and an engine as drive sources.

2. Description of the Related Art Conventionally, in a hybrid vehicle, a vehicle having a first clutch between an engine and a drive motor is known in a drive transmission path from an engine to a drive wheel through a drive motor (for example, Patent Document 1). reference).
In this prior art, the engine is provided with a starter motor. When the second clutch is released, the engine is started by engaging the first clutch and driving the drive motor. Start. On the other hand, when the second clutch is engaged, the first clutch is released and the engine is started by the starter motor.

JP2012-232690A

  Conventionally, when the first clutch is a dry-type clutch, it is known that heat is generated when the first clutch is engaged from the released state, and when the first clutch becomes hot due to this heat generation, the durability of the first clutch It is known to adversely affect sex.

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a hybrid vehicle control apparatus capable of improving the durability of a first clutch provided between an engine and a motor. .

In order to achieve the above object, the present invention provides:
In a hybrid vehicle control device in which a first clutch is interposed between an engine and a motor,
A first clutch current temperature detecting means for obtaining a current first clutch temperature of the first clutch, and a first clutch engagement temperature for estimating a temperature when the first clutch is engaged from a released state at the current temperature; Establishing means,
When the estimated temperature by the first clutch engagement temperature estimation means is estimated to exceed a preset engagement upper limit temperature, the first switching is performed by restricting or forcibly switching the mode with the engagement of the first clutch. A control apparatus for a hybrid vehicle is provided, characterized in that clutch temperature rise avoiding means for executing a clutch temperature rise avoiding process for avoiding the temperature of one clutch from exceeding the upper limit temperature at the time of engagement is provided.

In the control apparatus for a hybrid vehicle of the present invention, when the first clutch is engaged, the clutch temperature increase avoidance means executes the clutch temperature increase avoidance process when the engagement upper limit temperature is exceeded. And by this clutch temperature rise avoidance process, it is avoided that the temperature of the said 1st clutch exceeds the upper limit temperature at the time of engagement by the restriction | limiting or forced switching of the mode switching accompanying the fastening of the said 1st clutch.
Thereby, the durability of the first clutch can be improved.

1 is an overall system diagram of a control apparatus for a hybrid vehicle according to a first embodiment. 3 is an EV-HEV selection map used for mode switching by mode switching control means in the hybrid vehicle control apparatus of the first embodiment. 3 is a flowchart showing a flow of a clutch temperature increase avoidance process in the hybrid vehicle control apparatus of the first embodiment. FIG. 3 is a temperature-life characteristic diagram showing the relationship between the temperature and the life (durability) of the first clutch in the hybrid vehicle control apparatus of the first embodiment. FIG. 3 is a block diagram showing a configuration for executing the clutch temperature increase avoidance process in the hybrid vehicle control apparatus of the first embodiment. 3 is a flowchart showing a flow of a clutch temperature increase avoidance process in the hybrid vehicle control apparatus of the first embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for realizing a hybrid vehicle control device of the present invention will be described below based on the embodiments shown in the drawings.
(Embodiment 1)
First, the configuration will be described.
The configuration of the FF hybrid vehicle (an example of a hybrid vehicle) to which the control device according to the first embodiment is applied will be described by dividing it into “entire system configuration” and “detailed control configuration”.

[Overall system configuration]
FIG. 1 shows an overall system of an FF hybrid vehicle. Hereinafter, the overall system configuration of the FF hybrid vehicle will be described with reference to FIG.

As shown in FIG. 1, the drive system of the FF hybrid vehicle includes a starter motor 1, a horizontally installed engine 2, a first clutch 3, a motor / generator (hereinafter referred to as a motor) 4, and a second clutch. 5 and a belt-type continuously variable transmission 6 (abbreviated as “CVT”).
The output shaft of the belt type continuously variable transmission 6 is drivingly connected to the left and right front wheels 10R and 10L via a final reduction gear train 7, a differential gear 8, and left and right drive shafts 9R and 9L. The left and right rear wheels 11R and 11L are driven wheels.

The starter motor 1 is a cranking motor that has a gear that meshes with an engine start gear provided on the crankshaft of the engine 2 and that rotates the crankshaft when the engine is started.
The engine 2 is an engine disposed in the front room with the crankshaft direction as the vehicle width direction, and includes an electric water pump 12 and a crankshaft rotation sensor 13 that detects reverse rotation of the engine 2.

  The first clutch 3 is a normally open dry multi-plate friction clutch that is hydraulically interposed between the engine 2 and the motor 4, and complete engagement / slip engagement / release is controlled by the first clutch oil pressure.

  The motor 4 is a three-phase AC permanent magnet synchronous motor connected to the engine 2 via the first clutch 3. The motor 4 uses a high-power battery 21 described later as a power source, and an inverter 26 that converts direct current to three-phase alternating current during power running and converts three-phase alternating current to direct current during regeneration is connected to a stator coil via an AC harness 27. It is connected.

  The second clutch 5 is a hydraulically operated wet multi-plate friction clutch interposed between the motor 4 and the left and right front wheels 10R, 10L as drive wheels, and is fully engaged / slip engaged / Opening is controlled. The second clutch 5 of the first embodiment uses the forward clutch 5a and the reverse brake 5b provided in the forward / reverse switching mechanism of the belt type continuously variable transmission 6 using planetary gears. That is, the forward clutch 5a functions as the second clutch 5 during forward travel, and the reverse brake 5b functions as the second clutch 5 during reverse travel.

The belt-type continuously variable transmission 6 is a transmission that obtains a continuously variable transmission ratio by changing the belt winding diameter by the transmission hydraulic pressure to the primary oil chamber and the secondary oil chamber.
The belt type continuously variable transmission 6 includes a main oil pump 14, a sub oil pump 15, and a control valve unit (not shown) as a hydraulic system.
The main oil pump 14 is a pump mechanically driven by the motor shaft (= transmission input shaft) of the motor 4.
The sub-oil pump 15 is a pump that is driven by a motor (not shown) and is used as an auxiliary pump that mainly generates a hydraulic pressure for lubricating cooling.
The control valve unit forms the first and second clutch hydraulic pressures and the shift hydraulic pressure with the line pressure PL generated by regulating the pump discharge pressure from the main oil pump 14 as a source pressure.

  The first clutch 3, the motor 4 and the second clutch 5 constitute a one-motor / two-clutch drive system. ) ”And“ WSC mode ”. The “EV mode” is an electric vehicle mode in which the first clutch 3 is disengaged, the second clutch 5 is engaged, and only the motor 4 is used as a drive source. Travel in this “EV mode” is referred to as “EV travel”. The “HEV mode” is a hybrid vehicle mode in which both the clutches 3 and 5 are engaged and the engine 2 and the motor 4 are used as driving sources, and traveling in the “HEV mode” is referred to as “HEV traveling”. The “WSC mode” is a travel mode in which the first clutch 3 is engaged when the engine 2 is started and the second clutch 5 is slip-engaged with a transmission torque capacity corresponding to the required driving force.

  In principle, the motor 4 described above is driven as a generator during a braking operation to perform a regenerative operation. Therefore, a regenerative cooperative brake unit 16 that controls the total braking torque of the regenerative braking torque and the hydraulic braking torque at the time of braking operation is provided. The regenerative cooperative brake unit 16 includes a brake pedal, an electric booster, and a master cylinder, and the electric booster shares a hydraulic braking force by subtracting the regenerative braking force from the required braking force that appears in the pedal operation amount when the brake is operated. In this way, cooperative control for regenerative / hydraulic pressure is performed.

The power supply system of the FF hybrid vehicle includes a high-power battery 21 as a motor / generator power supply and a 12V battery 22 as a 12V system load power supply.
The high-power battery 21 is a secondary battery mounted as a power source for the motor 4. For example, a lithium ion battery in which a cell module constituted by a large number of cells is set in a battery pack case is used.
The high-power battery 21 has a built-in junction box (not shown) in which relay circuits for supplying / cutting off / distributing strong power are integrated. Further, the high-power battery 21 is provided with a cooling fan unit 24 having a battery cooling function and a lithium battery controller 86 for monitoring a battery charge capacity (battery SOC) and a battery temperature.

  The high-power battery 21 and the motor 4 are connected via a DC harness 25, an inverter 26, and an AC harness 27. Further, the inverter 26 is provided with a motor controller 83 that performs power running / regenerative control. That is, the inverter 26 converts the direct current from the DC harness 25 into the three-phase alternating current to the AC harness 27 during power running that drives the motor 4 by discharging the high-power battery 21. Further, the inverter 26 converts the three-phase alternating current from the AC harness 27 into the direct current to the DC harness 25 during regenerative charging of the high-power battery 21 by power generation by the motor 4.

  The 12V battery 22 is a secondary battery mounted as a power source for a 12V system load that is an auxiliary machine, and for example, a lead battery mounted in an engine vehicle or the like is used. The high voltage battery 21 and the 12V battery 22 are connected via a DC branch harness 25a, a DC / DC converter 37, and a battery harness 38. The DC / DC converter 37 converts a voltage of several hundred volts from the high-power battery 21 into 12V. By controlling the DC / DC converter 37 with the hybrid control module 81, the charge amount of the 12V battery 22 is increased. The configuration is to be managed.

As a control system for the FF hybrid vehicle, a hybrid control module 81 is provided as an integrated control means having a function of appropriately managing energy consumption of the entire vehicle.
Further, as a control means connected to the hybrid control module 81, an engine control module 82, a motor controller 83, a CVT control unit 84, and a lithium battery controller 86 are provided.
These control means including the hybrid control module 81 are connected via a CAN communication line 87 (CAN is an abbreviation for “Controller Area Network”) so that bidirectional information can be exchanged.

The hybrid control module 81 performs various controls based on input information from the controllers 82, 83, 84, 86 and the sensor group 90.
The engine control module 82 performs fuel injection control, ignition control, fuel cut control, and the like of the engine 2.
The motor controller 83 performs power running control, regeneration control, and the like of the motor 4 by the inverter 26.
The CVT control unit 84 performs engagement hydraulic pressure control of the first clutch 3, engagement hydraulic pressure control of the second clutch 5, shift hydraulic pressure control of the belt type continuously variable transmission 6, and the like.
The lithium battery controller 86 manages the battery SOC, battery temperature, and the like of the high-power battery 21.

  The sensor group 90 is provided as a traveling state detection unit that detects the traveling state of the vehicle. The sensor group 90 includes an ignition switch 91, an accelerator opening sensor 92, a vehicle speed sensor 93, a motor speed sensor 94, an acceleration sensor 95, a brake stroke sensor 96, a steering angle sensor 97, and an ambient temperature sensor 98.

The hybrid control module 81 includes mode switching selection means for selecting the above-described travel mode.
This travel mode selection is based on the EV-HEV selection map shown in FIG. 2, and the travel mode is searched based on the position on the map of the operating point determined by the accelerator opening APO and the vehicle speed VSP. Is selected as the target travel mode.

In this EV-HEV selection map, EV → HEV switching line, HEV → EV switching line, and HEV → WSC switching line are set.
The EV → HEV switching line is set to switch from the “EV mode” to the “HEV mode” when the operating point (APO, VSP) existing in the EV region crosses, and is indicated by a solid line in the figure.
The HEV → EV switching line is set to switch from the “HEV mode” to the “EV mode” when the operating point (APO, VSP) existing in the HEV region crosses, and is indicated by a dotted line in the figure.
The HEV⇒WSC switching line is set to switch to the “WSC mode” when the operating point (APO, VSP) enters the WSC region when the “HEV mode” is selected, and is indicated by a one-dot chain line in the figure. .
The HEV → EV switching line and the EV → HEV switching line are set with a hysteresis amount as a line dividing the EV area and the HEV area.

  When switching from the above-described EV mode to the HEV mode, the hybrid control module 81 controls the engine control module 82 and the motor controller 83 to perform engine start control.

  In this case, the first clutch 3 is switched from the disengaged state to the engaged state, the motor torque is increased, torque is transmitted to the engine 2, and fuel injection is performed when the engine speed increases to a speed at which the engine can be started. Then, the engine 2 is started. In the first embodiment, the starter motor 1 is provided for starting the engine 2. However, the start using the starter motor 1 is performed only in a limited case, and will be described below. The engine start to be performed is a start using the motor 4.

When it is estimated that the first clutch 3 becomes higher than the engagement upper limit temperature T _EN lim during the transition from the EV mode to the HEV mode, the hybrid control module 81 performs the HEV mode by the clutch temperature increase avoidance process. Regulate the transition to.

Details of the clutch temperature increase avoidance process will be described below with reference to FIGS.
First, the flow of the clutch temperature rise avoidance process will be described based on the flowchart of FIG.
This clutch temperature increase avoidance process is started when the switching determination from the HEV mode to the EV mode is made based on the EV-HEV selection map shown in FIG.
Note that conditions other than the EV-HEV selection map are also set as conditions for switching to the EV mode. For example, the compressor of the air conditioner driven by the engine 2 is turned off, the engine negative pressure used in the regenerative cooperative brake unit 16 is accumulated, the battery SOC is accumulated more than a set value, the engine water temperature, This includes a sufficiently high oil temperature. Conversely, the condition for prohibiting switching to the EV mode includes when traveling on an uphill road.

In first step S101, it is determined whether or not the first clutch estimated temperature sTcl1 is equal to or lower than a preset clutch upper limit temperature threshold value Tcllim. When the first clutch estimated temperature sTcl1 is equal to or lower than the clutch upper limit temperature threshold value Tcllim, the process proceeds to step S102. When the first clutch estimated temperature sTcl1 is lower than the clutch upper limit temperature threshold value Tcllim, the determination in step S101 is repeated.
The clutch upper limit temperature threshold value Tcllim is set to an upper limit temperature at which the durability of the first clutch 3 does not decrease. That is, as shown in FIG. 4, the durability of the first clutch 3, which is a dry multi-plate clutch, decreases as the temperature increases. Therefore, the clutch upper limit temperature threshold value Tcllim is set as a temperature at which a certain degree of durability can be secured.

In the subsequent step S102, it is determined whether or not the first clutch estimated temperature T _EN cl1 during engagement is equal to or lower than the upper limit temperature T _EN lim during engagement. When the engagement first clutch estimated temperature T _EN cl1 is equal to or lower than the engagement upper limit temperature T _EN lim, the process proceeds to step S103, and when it exceeds the engagement upper limit temperature T _EN lim, step S102 is repeated.
Here, the engagement upper limit temperature T _EN lim is an estimated temperature of the first clutch 3 when the first clutch 3 is immediately engaged after the first clutch 3 is once released. Further, the engagement upper limit temperature T _EN lim may be the same value as the clutch upper limit temperature threshold value Tcllim, or may be set to a temperature slightly higher than the clutch upper limit temperature threshold value Tcllim. In any case, the engagement upper limit temperature T _EN lim and the clutch upper limit temperature threshold value Tcllim are both upper limit values for preventing the first clutch 3 from being further heated from the viewpoint of durability.

In step S103 which proceeds when the first clutch estimated temperature T _EN cl1 at the time of engagement is equal to or lower than the upper limit temperature T _EN lim at the time of engagement, the clutch 2 rises after allowing the engine 2 to stop, that is, switch to the EV mode. The avoidance process ends.

Next, the configuration for obtaining the first clutch estimated temperature sTcl1 in step S101 and the configuration for obtaining the engaged first clutch estimated temperature T _EN cl1 in step S102 will be described based on FIG.
The first clutch estimated temperature sTcl1 and the engaged first clutch estimated temperature T _EN cl1 are executed by the clutch temperature rise avoiding unit 100 shown in FIG.
The clutch temperature increase avoidance unit 100 includes a current CL1 temperature estimation unit 110, a startup CL1 temperature increase estimation unit 120, an engine stop permission determination unit 130, and an addition unit 140.

  The current CL1 temperature estimation unit 110 estimates the first clutch estimated temperature sTcl1 that is the current temperature of the first clutch 3. That is, the first clutch 3 is a rotating body and is disposed inside the rotor of the motor 4, and it is difficult to detect the actual temperature. Therefore, in the first embodiment, the temperature of the first clutch 3 is estimated.

As shown in the figure, the current CL1 temperature estimation unit 110 inputs the heat dissipation coefficient, the ambient temperature, the differential rotation speed, the first clutch torque (CL1 torque), the time, and the heat capacity, and estimates the first clutch estimated temperature sTcl1. .
That is, the temperature of the first clutch 3 (first clutch estimated temperature sTcl1) can be obtained from the ambient temperature and the heat dissipation coefficient determined from the material and layout. In the present embodiment, the ambient temperature is detected by an ambient temperature sensor 98 that detects the ambient temperature of the first clutch 3. Further, instead of the ambient temperature sensor 98, the temperature of the lubricating oil or the cooling water supplied to the unit accommodating the first clutch 3 and the motor 4 may be detected and estimated from the detected value.
Here, the numerical value calculated | required beforehand by experiment etc. is used for the thermal radiation coefficient of the 1st clutch 3. FIG.

The startup CL1 temperature rise estimation unit 120 shown in FIG. 5 obtains an estimated rise temperature when the first clutch 3 is engaged from the released state as the engine 2 starts. A value obtained by adding the estimated rising temperature and the above-described first clutch estimated temperature sTcl1 by the adding unit 140 is an engagement first clutch estimated temperature T _EN cl1.
The estimated temperature rise at the time of engagement of the first clutch 3 is determined by the differential rotation speed (difference between the motor rotation speed and the engine rotation speed) and the transmission torque capacity (CL1 torque) at the time of clutch engagement, the time during which these act and the material It is obtained from the heat capacity coefficient.
The transmission torque capacity, the operation time, and the heat capacity coefficient can be obtained in advance by experiments or the like, and these can be processed as constant values. Therefore, the CL1 temperature rise estimation unit 120 at the time of starting is based on an estimated rise temperature table in which a plurality of patterns are set for the estimated rise temperature, which becomes higher as the difference rotational speed is higher with these constant values. I want to ask.

The engine stop permission determination unit 130 shown in FIG. 5 receives the preset clutch upper limit temperature threshold value Tcllim and the engagement upper limit temperature T _EN lim with preset hysteresis. When the input first clutch estimated temperature sTcl1 and engaged first clutch estimated temperature T _EN cl1 are equal to or lower than the clutch upper limit temperature threshold Tcllim and engaged upper limit temperature T _EN lim, respectively, engine stop permission determination is performed.

(Operation of Embodiment 1)
In the first embodiment, when the EV mode is selected based on the EV-HEV selection map of FIG. 2 during traveling in the HEV mode, the first clutch 3 is engaged at the upper limit temperature T _EN lim as follows. If there is a risk that the temperature will exceed 1, the transition is prohibited.
That is, when the first clutch 3 is repeatedly connected and disconnected at a certain high temperature, the first clutch 3 itself is at a high temperature as well as the ambient temperature. Under such circumstances, when the first clutch 3 is engaged in order to transition to the EV mode and immediately thereafter to transition to the HEV mode, the temperature may exceed the engagement upper limit temperature T _EN lim. And when the 1st clutch 3 becomes high temperature in this way, there exists a possibility of having a bad influence on durability.

Therefore, in the first embodiment, in such a situation, that is, when the first clutch estimated temperature T _EN cl1 at the time of engagement exceeds the upper limit temperature T _EN lim at the time of engagement, the engine stop is prohibited and the HEV is prohibited. Hold in mode. Thereby, it can avoid that the 1st clutch 3 becomes high temperature as mentioned above, and can suppress a durable fall.

(Effect of Embodiment 1)
The effects of the hybrid vehicle control device of the first embodiment are listed below together with the actions.
1) A control device for a hybrid vehicle according to Embodiment 1
An engine 2 and a motor 4 included in a drive source of the vehicle;
A first clutch 3 interposed between the engine 2 and the motor 4;
A sensor group 90 as a traveling state detection means for detecting the traveling state of the vehicle including the operation state of the driver;
Based on the detection of the sensor group 90 as the traveling state detecting means, a request for transition to the hybrid vehicle mode (HEV mode) is generated during traveling in the electric vehicle mode (EV mode) with the first clutch 3 released. In this case, the first clutch 3 is engaged and the engine 2 is started. When a request for transition to the EV mode occurs during traveling in the HEV mode, the first clutch 3 is released and the engine 2 is released. A hybrid control module 81 that executes travel mode switching control based on the map of FIG.
In a hybrid vehicle control device comprising:
A current CL1 temperature estimation unit 110 is provided as first clutch current temperature detecting means for obtaining a first clutch estimated temperature sTcl1 as a current first clutch temperature Tcl1 of the first clutch 3, and the first clutch 3 is A start-up CL1 temperature rise estimation unit 120 serving as a first clutch engagement temperature estimation means for estimating a temperature when engaged from a released state at a temperature;
When it is estimated that the first clutch estimated temperature T _EN cl1 at the time of engagement as the estimated temperature by the current CL1 temperature estimating unit 110 exceeds the preset upper limit temperature T _EN lim at the time of engagement, the first clutch 3 A clutch temperature increase avoidance unit 100 is provided that performs a clutch temperature increase avoidance process for avoiding the temperature of the first clutch 3 from exceeding the engagement upper limit temperature T _EN lim due to the restriction of mode switching with engagement. And
As described above, when the first clutch 3 is engaged, the temperature of the first clutch 3 (first clutch estimated temperature sTcl1) may exceed the engagement upper limit temperature T _EN lim. Performs the clutch temperature rise avoidance process. Therefore, it is possible to prevent the temperature of the first clutch 3 (first clutch estimated temperature sTcl1) from exceeding the engagement upper limit temperature T _EN lim and improve the durability of the first clutch 3.

2) The control device for the hybrid vehicle of the first embodiment is
In the clutch temperature increase avoidance hand unit 100, as the clutch temperature increase avoidance process, when the travel mode switching control means determines the transition from the HEV mode to the EV mode, the clutch temperature increase avoidance hand unit 100 starts as the first clutch engagement temperature estimation means. the CL1 temperature increase estimating unit 120 performs the temperature estimation of the time of fastening of the first clutch 3 (obtaining a first clutch estimated temperature _T EN cl1 during engagement), when said engagement first clutch estimated temperature _T EN cl1 during this engagement When the temperature exceeds the upper limit temperature T _EN lim, a process for prohibiting the engine stop is executed as a process for prohibiting the transition to the EV mode.
As described above, when the transition to the EV mode is determined at the time of traveling in the HEV mode, if the transition to the HEV mode is determined immediately after the transition to the EV mode, the first clutch 3 is engaged and the engine is started. The temperature of the first clutch 3 rises.
Therefore, the engagement first clutch estimated temperature T _EN cl1 calculated by the starting CL1 temperature rise estimation unit 120 and the addition unit 140 as the first clutch engagement temperature estimation means exceeds the engagement upper limit temperature T _EN lim. In this case, the transition to the EV mode is prohibited.
Therefore, when the engine 2 is not stopped and the transition to the HEV mode is again determined immediately after the transition to the EV mode and the engine is started, the temperature of the first clutch 3 exceeds the engagement upper limit temperature T _EN lim. Can be avoided.
Thereby, the durability of the first clutch can be improved.

3) The control device for the hybrid vehicle in the first embodiment
The current CL1 temperature estimation unit 110 serving as the first clutch current temperature detection means obtains a first clutch estimated temperature sTcl1 that is an estimated value of the current temperature of the first clutch CL1 based on at least the ambient temperature of the first clutch CL1. It is characterized by seeking.
The temperature of the first clutch 3 can be obtained from the ambient temperature and the heat dissipation coefficient determined from the material and layout. Therefore, since the heat radiation coefficient determined from the material and layout is known in advance, the first clutch estimated temperature sTcl1 can be obtained with high accuracy based on the ambient temperature.
Further, since the first clutch 3 is a rotating body, in order to directly obtain the temperature thereof, it is necessary to transmit and receive power and detection data between the rotating body and the vehicle body side, which is difficult to install and is expensive. It becomes. Therefore, by estimating the temperature of the first clutch 3, the current temperature of the first clutch 3 can be obtained at low cost.

4) The control device for the hybrid vehicle in the first embodiment
The first clutch engagement temperature estimation means adds the estimated increase temperature due to engagement estimated by the start CL1 temperature increase estimation unit 120 to the first clutch estimated temperature sTcl1 as the current temperature of the first clutch 3. The first clutch estimated temperature T _EN cl1 is estimated at the time of engagement.
Therefore, it is possible to estimate the temperature at the time of engagement before the first clutch 3 is actually engaged and the temperature of the first clutch 3 actually increases.
Therefore, it is possible to avoid the temperature of the first clutch 3 from exceeding the upper limit value with higher accuracy.

5) The control device for the hybrid vehicle in the first embodiment
The first clutch engagement temperature estimation means obtains the estimated increased temperature based on a differential rotation between the rotation speed of the engine 2 and the rotation speed of the motor 4.
The temperature rise at the time of engagement of the first clutch 3 is determined by the differential rotation speed (difference between the motor rotation speed and the engine rotation speed) at the time of clutch engagement, the transmission torque capacity (CL1 torque), the time during which these act and the material. It is obtained by the heat capacity coefficient.
Since the heat capacity coefficient determined by the transmission torque capacity and the operating time can be predicted to some extent, it is possible to estimate the first clutch estimated temperature T _EN cl1 at the time of engagement with high accuracy by obtaining the estimated rising temperature according to the differential rotation. It becomes.

(Other embodiments)
Next, a control apparatus for a hybrid vehicle according to another embodiment will be described.
Since the other embodiment is a modification of the first embodiment, the same reference numerals as those in the first embodiment are assigned to the same components as those in the first embodiment, and the description thereof is omitted. Only the differences will be described.

(Embodiment 2)
Based on the flowchart of FIG. 6, the hybrid vehicle control apparatus of the second embodiment will be described.
The second embodiment is different from the first embodiment in the contents of the clutch temperature increase avoidance process, and this clutch temperature increase avoidance process is executed during traveling in the EV mode.
In the first step S201, it is determined whether or not the accelerator opening is in an OFF state in which the accelerator pedal is not depressed. If the accelerator is OFF, the process proceeds to step S202. If the accelerator is not OFF, step S201 is repeated.

In step S202, which proceeds when the accelerator is OFF, it is determined whether or not the motor rotational speed has exceeded a preset forced switching determination rotational speed Nmlim. The forced switching determination rotational speed Nmlim is set to a value corresponding to a lower vehicle speed than the vehicle speed VSP of the accelerator opening APO = 0 on the EV → HEV switching line shown in FIG.
If the motor rotational speed exceeds the forced switching determination rotational speed Nmlim, the process proceeds to step S101. If the motor rotational speed does not exceed the forced switching determination rotational speed Nmlim, step S202 is repeated.
Steps S101 and S102 that proceed when the forced switching determination rotational speed Nmlim is exceeded perform the same processing as in the first embodiment, and will not be described.

In step S101, if the current first clutch estimated temperature sTcl1 does not exceed the clutch upper limit temperature threshold value Tcllim and the first clutch 3 is engaged, the engagement first clutch estimated temperature T _EN cl1 becomes the engagement upper limit temperature T _EN lim. If it exceeds, the process proceeds to step S203. In step S203, the engine is immediately started to forcibly switch the running mode to the HEV mode.

Therefore, in the second embodiment, during the EV mode traveling, for example, when the motor rotation speed increases on a downhill or the like and then the engine is started, the temperature of the first clutch 3 is set to the engagement upper limit temperature T _EN. If it is estimated that lim is exceeded, the engine is forcibly started immediately. As described above, after the engine start request is actually determined and the engine is forcibly started earlier than the engine is started, the temperature of the first clutch 3 exceeds the engagement upper limit temperature T _EN lim. Can be avoided.

2-1) The control device for the hybrid vehicle of the second embodiment is:
The clutch temperature rise avoiding unit 100 performs the clutch temperature rise avoiding process when the motor rotational speed exceeds a preset forced switching determination rotational speed Nmlim during traveling in the EV mode. The temperature is equal to or lower than a preset clutch upper limit temperature threshold value Tcllim, and the first clutch estimated temperature T _EN cl1 at the time of engagement of the first clutch accompanying the engine start thereafter exceeds the upper limit temperature T _EN lim at the time of engagement. In this case, a forced switching process for forcibly shifting to the HEV mode at the present time is executed.
Therefore, when the EV mode is changed to the HEV mode, the first clutch 3 is forcibly changed to the HEV mode before the temperature of the first clutch 3 exceeds the engagement upper limit temperature T _EN lim. The temperature at which the first clutch 3 is engaged can be suppressed to prevent the temperature of the first clutch 3 from exceeding the upper limit temperature T _EN lim during engagement.
Thereby, the durability of the first clutch 3 can be improved.

  As mentioned above, although the control apparatus of the hybrid vehicle of this invention was demonstrated based on embodiment, about a specific structure, it is not restricted to this embodiment, The invention which concerns on each claim of a claim Design changes and additions are permitted without departing from the gist of the present invention.

In the embodiment, the front-wheel drive FF vehicle is exemplified as the hybrid vehicle. However, the present invention is not limited to this and can be applied to a rear-wheel drive vehicle and an all-wheel drive vehicle.
In the embodiment, as the first clutch current temperature detecting means, means for estimating the current first clutch temperature based on the ambient temperature or the like is used. However, a sensor for directly detecting the first clutch temperature may be provided. Good.
Further, in the embodiment, an example is shown in which a table is used as the temperature estimation means at the time of first clutch engagement, but the present invention is not limited to this. You may make it ask.

2 Engine 3 First clutch 4 Motor / generator (motor)
81 Hybrid control module (travel mode switching control means, first clutch engagement temperature estimation means, clutch temperature increase avoidance means)
90 sensor group (running state detection means)
98 Atmosphere temperature sensor (atmosphere temperature detection means)
100 Clutch temperature rise avoidance section 110 Current CL1 temperature estimation section 120 Start-up CL1 temperature rise estimation section 130 Engine stop permission determination section 140 Addition section sTcl1 First clutch estimated temperature Tcllim Clutch upper limit temperature threshold T _EN cl1 First clutch estimated temperature at engagement T _EN lim upper limit temperature at fastening

Claims (5)

An engine and a motor included in the drive source of the vehicle;
A first clutch interposed between the engine and the motor;
Traveling state detection means for detecting the traveling state of the vehicle including the operation state of the driver;
Based on the detection of the traveling state detecting means, when a request for transition to the hybrid vehicle mode is made during traveling in the electric vehicle mode in which the first clutch is released, the first clutch is engaged to start the engine. And a travel mode switching control means for releasing the first clutch and stopping the engine when a request for transition to the electric vehicle mode occurs during traveling in the hybrid vehicle mode.
In a hybrid vehicle control device comprising:
A first clutch current temperature detecting means for obtaining a current first clutch temperature of the first clutch, and a first clutch engagement temperature for estimating a temperature when the first clutch is engaged from a released state at the current temperature; Establishing means,
When the estimated temperature by the first clutch engagement temperature estimation means is estimated to exceed a preset engagement upper limit temperature, the first switching is performed by restricting or forcibly switching the mode with the engagement of the first clutch. setting the clutch temperature rise avoidance means the temperature of the first clutch to perform a clutch temperature rise avoidance process to avoid exceeding the fastening at the upper limit temperature,
The clutch temperature rise avoiding means, as the clutch temperature rise avoiding process, when the motor rotation speed exceeds a preset forced switching determination rotation speed during traveling in the electric vehicle mode, When the current temperature is equal to or lower than a preset clutch upper limit temperature and the estimated temperature at the time of engagement of the first clutch accompanying the subsequent engine start exceeds the engagement upper limit temperature, the hybrid vehicle is forcibly forced at the present time. A control device for a hybrid vehicle, which executes a forced switching process for transition to a mode . In the hybrid vehicle control device according to claim 1,
The clutch temperature increase avoiding means, as the clutch temperature increase avoiding process, is executed by the first clutch engagement temperature estimating means when the travel mode switching control means determines a transition from the hybrid vehicle mode to the electric vehicle mode. A hybrid vehicle control device that performs temperature estimation at the time of engagement of the first clutch, and executes processing for restricting transition to the electric vehicle mode when the estimated temperature exceeds the engagement upper limit temperature. . In the hybrid vehicle control device according to claim 1 or 2 ,
The control apparatus for a hybrid vehicle, wherein the first clutch current temperature detection means estimates a current temperature of the first clutch based on at least an ambient temperature of the first clutch. In the control apparatus of the hybrid vehicle of any one of Claims 1-3 ,
The first clutch engagement temperature estimation means obtains an estimated temperature at the time of engaging the first clutch by adding an estimated increase temperature due to the engagement to the current temperature of the first clutch. apparatus. The hybrid vehicle control device according to claim 4 ,
The controller for a hybrid vehicle, wherein the first clutch engagement temperature estimation means obtains the estimated increased temperature based on a differential rotation between the engine speed and the motor speed.