Controller for vehicle

The present invention relates to a vehicle control device used in a hybrid vehicle equipped with a power generation source including an internal combustion engine and two types of motors.

A normal vehicle powered only by an internal combustion engine cannot maintain the maximum thermal efficiency (minimum fuel consumption rate) of the internal combustion engine over the entire running speed range. On the other hand, in the hybrid vehicle, for example, as described in Patent Document 1, the internal combustion engine is always set to the optimum efficiency point (the point where the thermal efficiency is the highest and the fuel consumption rate can be minimized). ), So you can get much better fuel performance than a normal vehicle.

By the way, when the internal combustion engine is operated at the optimum efficiency point, the driving force of the internal combustion engine may be insufficient or excessive with respect to the required driving force (axle required output) at that time. Therefore, in a hybrid vehicle, a means for compensating for the excess or deficiency is required.

Therefore, for example, as described in Patent Document 2, a hybrid vehicle provided with two motors (electric motor M and generator G) for compensating for excess or deficiency of driving force is known. Hereinafter, for the sake of convenience, the electric motor M will be referred to as the first motor, and the generator G will be referred to as the second motor. ", And when the driving force of the internal combustion engine becomes excessive, the excess is absorbed by the" regeneration "of the second motor.<patcit num="1"><text>Japanese Patent Application Laid-Open No. 5-229351</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 9-184436</text></patcit>

<p> However, as described above, simply operating the internal combustion engine at the optimum efficiency point and compensating for the excess or deficiency of the driving force of the internal combustion engine by two motors causes the following problems.</p><p> That is, the optimum efficiency point of the internal combustion engine is only an extremely narrow range (point) given by the function of the rotation speed and output torque of the internal combustion engine and the accelerator opening at that time, and in the actual running state, the internal combustion engine It often happens that the excess or deficiency of the driving force of the engine is highly probable. Therefore, the means (first motor and second motor) for compensating for the excess or deficiency of the driving force of the internal combustion engine frequently repeat the operation, and as a result, the temperature of the motor rises and the cooling system. There was a problem of increasing the burden on the engine.</p><p> Therefore, an object of the present invention is to investigate the relationship between the load of the motor and the operating time. Therefore, even if the load of the motor is large, the temperature rise of the motor is small if the operating time is short. On the other hand, paying attention to the fact that the temperature rise of the motor becomes high when the operation time is long even when the load of the motor is small, the operation of the motor is appropriately allowed by utilizing this fact. It is an object of the present invention to provide a vehicle control device capable of suppressing a temperature rise of a motor by stopping the motor and thereby reducing the burden on the cooling system.</p>

<p> In the vehicle control device according to claim 1, a power generation source including an internal combustion engine and two types of motors, a first gear element is connected to an output shaft of the internal combustion engine, and a second gear element is the second. A differential gear device that is connected to the output shaft of one of the two types of motors and the third gear element is connected to the output shaft and drive wheels of the other motor of the two types of motors. In a vehicle control device used for a hybrid vehicle provided with a fixing means for fixing the rotation of one of the types of motors, a vehicle speed detecting means for detecting the vehicle speed and an accelerator opening for detecting the accelerator opening. The detecting means, the determining means for determining whether or not the detected vehicle speed and the accelerator opening are within the operating region of the fixing means defined by the vehicle speed and the accelerator opening, and the determining means of the determining means. When the determination result is affirmative, the fixing means is provided with an operating means for operating the fixing means. In the vehicle control device according to claim 2, a power generation source including an internal combustion engine and two types of motors, a first gear element is connected to the output shaft of the internal combustion engine, and the second gear element is the second. A differential gear device that is connected to the output shaft of one of the two types of motors and the third gear element is connected to the output shaft and drive wheel of the other motor of the two types of motors. In a vehicle control device used for a hybrid vehicle provided with a fixing means for fixing the rotation of one of the types of motors, a transmission means intervening between the power generation source and the drive wheels, and the above-mentioned The gear ratio detecting means for detecting the gear ratio of the gear shifting means, the accelerator opening detecting means for detecting the accelerator opening, and the detection within the operating region of the fixed means defined by the gear ratio and the accelerator opening. It is characterized by including a determination means for determining whether or not the gear ratio and the accelerator opening are included, and an operating means for operating the fixing means when the determination result of the determination means is affirmative. And.</p>

<p> The vehicle control device according to claim 1 operates the fixing means when the operating state defined by the vehicle speed and the accelerator opening falls within the operating range of the fixing means defined by the vehicle speed and the accelerator opening. And fix the motor. Here, the operating region refers to an region including an operating state in which the frequency of appearance is high in a normal driving state. Therefore, according to the present invention, since the motor is stopped in the operating state where the frequency of appearance is high, heat generation of the motor can be prevented and the load on the cooling system can be reduced. In the present invention, the operation of the motor is permitted when the operating state is other than the predetermined state, but the operation of the motor in this case is sporadic and the operation time is short, so that even if the load of the motor is high. Even so, there is no problem because the heat generated by the motor is small and the load on the cooling system is light. In the vehicle control device according to claim 2, when the operating state defined by the gear ratio and the accelerator opening falls within the operating region of the fixing means defined by the gear ratio and the accelerator opening, the fixing means To fix the motor. Since it is the same as the invention of claim 1 except that the vehicle speed is replaced with the gear ratio, similarly, the motor is stopped in the operating state where the frequency of appearance is high to prevent the motor from generating heat, and the cooling system. It is possible to reduce the burden on.</p>

Hereinafter, examples of the present invention will be described with reference to the drawings, exemplifying application to a parallel hybrid vehicle. It should be noted that the identification or examples of various details and the examples of numerical values, character strings and other symbols in the following description are merely for reference in order to clarify the idea of the present invention, and all or part of them may be used as a reference. It is clear that the idea of the invention is not limited. In addition, detailed explanations of well-known methods, well-known procedures, well-known architectures, well-known circuit configurations, etc. (hereinafter referred to as "well-known matters") will be avoided, but this is also for the sake of brevity, and these are well-known. It does not intentionally exclude all or part of the matter. Such well-known matters are known to those skilled in the art at the time of filing the application of the present invention, and are therefore naturally included in the following description.

FIG. 1 is a conceptual configuration diagram of the present embodiment. In this figure, the output shaft 2 of the internal combustion engine 1 is connected to the carrier 5 (first gear element) of the planetary gear mechanism 4 (differential gear device) via the clutch 3. A sun gear 6 (second gear element), a plurality of planetary gears 7 that orbit around the sun gear 6 as the carrier 5 rotates, and a ring gear 8 (third gear element) that meshes with the planetary gear 7. ) And. The clutch 3 is not an essential component of the present embodiment. It is a component required in the modification described later.

The ring gear 8 of the planetary gear mechanism 4 is the output of the rotor 9a of the first motor 9 (the other motor of the two types of motors) via the first output gear 13 and the second output gear 14. It is connected to a shaft 9b (the output shaft of the other motor of the two types of motors), and the stator 9c of the first motor 9 is fixed to the case 10. Further, the sun gear 6 of the planetary gear mechanism 4 is an output shaft 11b (output shaft of one of the two types of motors) of the rotor 11a of the second motor 11 (one of the two types of motors). ), And the stator 11c of the second motor 11 is also fixed to the case 10.

Here, the movable side friction plate 12a of the multi-plate brake 12 (fixing means) is attached to the output shaft 11b of the second motor 11, and the output shaft 11b of the second motor 11 has this movable side friction. It can be arbitrarily fixed to the case 10 via the plate 12a and the fixed side friction plate 12b arranged to face each other. On the other hand, a second output gear 14 is attached to the output shaft 9b of the first motor 9, and the output shaft 9b of the first motor 9 has a transmission shaft 15 and a mechanical transmission 16 (transmission means). And is connected to the drive wheels 18 via the differential device 17. The mechanical transmission 16 is not an essential component of the present embodiment. It is a component required in the modification described later.

The illustrated hybrid vehicle having such a configuration can run in the following three modes. &lt;Motor running mode&gt; This is a running mode that does not use the internal combustion engine 1 and is used when starting or running at an extremely low vehicle speed. In this mode, the output torque of the second motor 11 is controlled to 0, and the multi-plate brake 12 is released (that is, the movable friction plate 12a and the fixed friction plate 12b are not fastened). , The output torque of the first motor 9 is controlled so that a desired driving force (driving force corresponding to the accelerator opening F) can be obtained.

In the motor running mode, the output shaft 11b of the second motor 11 is not fixed to the case 10 due to the release of the multi-plate brake 12, and is in a rotation-free state. Therefore, the sun gear 6 of the planetary gear mechanism 4 Is also in a rotation-free state. Therefore, the operation (including stop) of the internal combustion engine 1 does not affect the driving force at all, and only the output torque of the first motor 9 meshes with the first output gear 13 and the first output gear 13. It is transmitted to the drive wheels 18 via the second output gear 14, the transmission shaft 15, the mechanical transmission 16 and the differential device 17.

&lt;Engine driving mode&gt; This is a driving mode in which the internal combustion engine 1 is used exclusively, and is used when driving at a high vehicle speed. In this mode, the multi-plate brake 12 is engaged (that is, the movable friction plate 12a and the fixed friction plate 12b are engaged), and then the clutch 3 is connected to control the output torque of the internal combustion engine 1. The desired driving force (driving force corresponding to the accelerator opening F) can be obtained.

In the engine running mode, the output shaft 11b of the second motor 11 is in a non-rotating state because it is fixed to the case 10 by fastening the multi-plate brake 12, so that the sun gear 6 of the planetary gear mechanism 4 is also the same. It is in a fixed rotation state. Therefore, the output torque of the internal combustion engine 1 is transmitted to the first output gear 13 via the carrier 5 of the planetary gear mechanism 4, the planetary gear 7, and the ring gear 8, and is meshed with the first output gear 13. It is transmitted to the drive wheels 18 via the output gear 14, the transmission shaft 15, the mechanical transmission 16, and the differential device 17.

Since the output shaft 9b of the first motor 9 also serves as the shaft of the first output gear 13, the first motor 9 may be driven if desired in this engine running mode. The output torque of the first motor 9 can be used to assist the driving force of the internal combustion engine 1.

&lt;Hybrid driving mode&gt; This is a driving mode peculiar to a hybrid vehicle and is used during general driving except for extremely low vehicle speed and high vehicle speed driving. The feature of this mode is that the internal combustion engine 1 is operated at the optimum efficiency point (also referred to as an ideal operating state), and the insufficient driving force and the excessive driving force of the internal combustion engine 1 in the operating state are set to the first motor 9. And the second motor 11 is to be supplemented by power running and regenerative operation. In this mode, the multi-plate brake 12 is released (that is, the movable friction plate 12a and the fixed friction plate 12b are not engaged), the clutch 3 is connected, and the operating state of the internal combustion engine 1 is changed to the above. By controlling the output torque and rotation speed of the first motor 9 and the second motor 11, the desired driving force (driving force corresponding to the accelerator opening F) can be obtained. To do.

In the hybrid drive mode, the output shaft 11b of the second motor 11 is not fixed to the case 10 due to the release of the multi-plate brake 12, so that it is in a rotation-free state, and so is the sun gear 6 of the planetary gear mechanism 4. Although it is in a rotation-free state, the rotation-free state of the sun gear 6 is regulated by controlling the output torque and rotation speed of the second motor 11, and part or all of the output torque of the internal combustion engine 1 is a planetary gear mechanism. It can be transmitted to the first output gear 13 via 4. Then, in this case, the sum of the output torque of the internal combustion engine 1 and the output torque of the first motor 9 is meshed with the first output gear 13, the second output gear 14, the transmission shaft 15, and the mechanical type. It can be transmitted to the drive wheels 18 via the transmission 16 and the differential device 17.

Further, in this hybrid driving mode, when the output torque of the internal combustion engine 1 is excessive, the rotation regulation of the sun gear 6 is weakened by controlling the output torque and the rotation speed of the second motor 11 in the decreasing direction, and the internal combustion is internalized. The output torque of the engine 1 can be used to regenerate the second motor 11, and the output torque of the internal combustion engine 1 transmitted to the first output gear 13 can be reduced.

The controller 19 is for controlling each of the above modes, and the controller 19 has various driving information necessary for the control, for example, a vehicle speed V from a vehicle speed sensor 20 (vehicle speed detecting means), an accelerator (not shown). Accelerator opening F from the accelerator opening sensor 21 (accelerator opening detecting means) that detects the amount of pedal operation, temperature T from the temperature sensor 22 that detects the temperature of the internal combustion engine 1 (or the temperature inside the engine room), the machine Information such as the shift position S of the type transmission 16 is input.

FIG. 2 is a conceptual configuration diagram of the controller 19. In this figure, the controller 19 has a microprogram control system configuration including a CPU 19a, a ROM 19b, a RAM 19c, an input / output unit 19d, and the like, although not particularly limited thereto. The controller 19 having such a configuration loads software resources such as a control program written in advance in ROM 19b into RAM 19c and executes the software resources on CPU 19a to obtain the software resources and hardware resources such as CPU 19a. The desired function is achieved by organic bonding.

FIG. 3 is a diagram showing a flowchart of a control program executed by the CPU 19a of the controller 19, and in particular, is a diagram showing a flowchart of a main part including the multi-plate brake 12 engagement control process which is the point of the present embodiment. Is. In the following description, for convenience, "fastening" of the multi-plate brake 12 is referred to as "ON", and "release" is referred to as "OFF".

In this flowchart, first, the driving mode determination process is executed based on various vehicle information (step S11), and it is determined whether or not the determined driving mode is the hybrid driving mode (step S12).

Then, if it is not the hybrid driving mode, the flow is terminated after executing the required control corresponding to the other driving modes (motor driving mode or engine driving mode) (step S13), while if it is the hybrid driving mode, it is. Performs the following specific processing.

That is, based on the vehicle speed V and the accelerator opening degree F, a process of determining whether or not the multi-plate brake 12 is in the "predetermined driving area" (operating area of the fixing means) that should be turned from OFF to ON is executed (step). S14, step S15: determination means), after executing the "multi-plate brake ON control process" (step S16: operating means) when it is determined that the vehicle is in the "predetermined operating area", the required corresponding to the hybrid driving mode (Step S17) is executed to end the flow. The "predetermined operating area" will be described in detail later.

FIG. 4 is a diagram showing a flowchart of the multi-plate brake ON control process. In this flowchart, first, it is determined whether or not the rotation speed of the second motor 11 is 0 (step S16a), and if it is not 0, the stop processing of the second motor 11 is executed (step S16b). , The determination of the rotation speed 0 is repeated again, and when the determination of the rotation speed 0 is determined, the ON control (engagement control) of the multi-plate brake 12 is executed (step S16c).

FIG. 5 is a conceptual diagram showing a predetermined operating area in which the multi-plate brake 12 should be turned from OFF to ON. In this figure, the vertical axis is the accelerator opening degree F, the horizontal axis is the vehicle speed V, and the hatching range is the predetermined driving region 23. A map similar to this figure is stored in ROM19b of the controller 19 in advance. This map is referred to when steps S14 and S15 of the above flowchart (see FIG. 3) are executed by the CPU 19a of the controller 19, and the accelerator opening F and the vehicle speed V at that time are included in the predetermined driving area 23. It is judged whether or not it is. Then, when the accelerator opening degree F and the vehicle speed V at that time are included in the predetermined driving region 23, the above-mentioned "multi-plate brake ON control process" (see FIG. 4) is executed.

As described above, the point of this embodiment is that the operating state (accelerator opening F and vehicle speed V) in the hybrid driving mode is in the predetermined operating region 23 in which the multi-plate brake 12 should be turned from OFF to ON. It is determined whether or not the brake 12 is installed, and if it is installed, the rotation speed of the second motor 11 is set to 0, and then the multi-plate brake 12 is forcibly turned on (fastened). By doing so, at least the operation of the second motor 11 is forcibly stopped, the temperature rise of the second motor 11 is suppressed, and the load on the cooling system is reduced. It is also one of the points that the predetermined operating area 23 is set according to the following findings.

FIG. 6 is a diagram plotting the combination of the accelerator opening F and the vehicle speed V in actual driving. As in FIG. 5, the vertical axis is the accelerator opening F and the horizontal axis is the vehicle speed V. The black dots in the figure represent the combination of the accelerator opening F and the vehicle speed V, and the density of the black dots represents the frequency of use (appearance frequency). In other words, the low-density part is an operating state that rarely appears (hereinafter referred to as "sporadic operation state"), and the high-density part (the part surrounded by a broken line) often appears (hereinafter referred to as "normal operation state"). ".). In this way, in a general driving state, there is a bias in the combination of the accelerator opening F and the vehicle speed V (sporadic driving state and normal driving state), and these driving states and motors (first motor 9 and second motor 9 and second motor 9 and second The following findings can be obtained by investigating the relationship between the heat generation of the motor 11).

That is, the temperature rise of the motor is given as a time integral value obtained by subtracting the amount of heat removed by the cooling system from the amount of heat generated by the motor itself. Even if the load on the motor is high and the heat generated is large, the temperature of the motor does not rise to the extent that it is of great concern. On the other hand, in the normal operation state, the frequency of appearance is considerably high (the above time integral value is high), so that the load of the motor is relatively high, not to mention the case where the load of the motor is high and the heat generation is large. Even if it is low, the temperature of the motor may rise to a level that cannot be ignored, depending on the frequency of appearance. Improving the capacity of the cooling system is certainly one way to deal with such a temperature rise, but it is a preferable measure because it causes the cooling system to become large and costly. Absent.

Therefore, in the present embodiment, when the vehicle is in the normal operation state (corresponding to the predetermined operation area 23), the multi-plate brake 12 is forcibly turned on (fastened) even in the hybrid driving mode. As a result, at least the output shaft 11b of the second motor 11 is fixed to the case 10 so that the second motor 11 is not operated, and thus the multi-plate brake 12 is forcibly turned on (fastened). During that time, the heat generated by the second motor 11 is suppressed so that the load on the cooling system can be reduced. As a result, it is possible to suppress an increase in cost without inviting an increase in the size of the cooling system (effect corresponding to claim 1).

Note that the heat generated by the motor can be a problem not only for the second motor 11 but also for the first motor 9, but since the operation of the first motor 9 can be freely controlled by the control from the controller 19, for example. , If the temperature of the first motor 9 is below the permissible range, the first motor 9 may be controlled to generate an auxiliary driving force, or the temperature of the first motor 9 may be within the permissible range. If it exceeds, the first motor 9 may be stopped to suppress the temperature rise, and the insufficient driving force may be supplemented by the control of the internal combustion engine 1.

Here, in the above embodiment, when the multi-plate brake 12 is forcibly turned on (fastened), it is determined whether or not the rotation speed of the second motor 11 is 0 (see step S16a in FIG. 4). And the control to set the rotation speed of the second motor 11 to 0 when the rotation speed is not 0 (see step S16b in FIG. 4) is executed. As shown in FIG. 1, the internal combustion engine 1 When the clutch 3 is provided between the planetary gear mechanism 4 and the planetary gear mechanism 4, the clutch 3 is turned OFF (released) to eliminate the above-mentioned determination and control processing (steps S16a and S16b). be able to.

Further, in the above embodiment, as the predetermined operating region 23, a single closed region having a box shape with an inclined side (see the hatched portion in FIG. 5) is shown, but this is only an example. It may have any other shape, and the number of regions is not limited to one. Further, it does not necessarily have to be a closed area, and may be an open area without one or several sides.

FIG. 7 is a diagram showing a preferable modification of the predetermined operating region 23. In this figure, the predetermined operating region 23 is composed of a first region 24 and a second region 25 in contact with one side or a plurality of sides or all sides of the first region 24. The first region 24 is an region in which the multi-plate brake 12 is forcibly turned on (fastened) when a combination of the accelerator opening F and the vehicle speed V enters the region, and the second region 25 is. , When the combination of accelerator opening F and vehicle speed V enters the area, the state of the multi-plate brake 12 is checked and if it is ON, it is within the range of maintaining that ON.

In such a modified example, assuming that one or both of the accelerator opening F and the vehicle speed V change and enter the second region 25 from outside the two regions via the first region 24. In this case, the multi-plate brake 12 keeps OFF while passing through the first region 24 and turns ON after entering the second region 25, but conversely, the second region 25 to the first When going out of the two areas through the first area 24, the multi-plate brake 12 keeps ON while passing through the first area 24, and turns off when the first area 24 is left. Therefore, since the ON / OFF switching conditions of the multi-plate brake 12 differ depending on the direction of entry and exit to each region, it is possible to obtain the effect of preventing frequent switching operations (chattering).

FIG. 8 is a diagram showing another preferred modification of the predetermined operating region 23. This figure is, for example, a transmission line diagram of a stepped transmission, and is applied when the mechanical transmission 16 (for example, a 5-speed transmission) of FIG. 1 is provided. In this figure, the vertical axis is the accelerator opening F, the horizontal axis is the vehicle speed V, the solid line in the figure is upshift (1 2, 2 3, 3 4, 4 5), and the dotted line is down. It represents a shift (5 4, 4 3, 3 2, 2 1). When the combination of the accelerator opening F and the vehicle speed V exceeds each solid line or broken line, the mechanical transmission 16 is changed (upshifted or downshifted).

Here, a specific area of the illustrated shift line diagram is indicated by hatching. This specific region is, for example, a region of 3 4 upshift and 4 5 upshift, and a region of a predetermined accelerator opening degree F or more. When the combination of the accelerator opening F and the vehicle speed V enters this specific area, the multi-plate brake 12 is forcibly turned on (fastened). This specific region corresponds to the first region 24 in FIG.

Also, in the area from this specific area to 3 4 downshift, when the combination of accelerator opening F and vehicle speed V enters that area, the state of the multi-plate brake 12 is checked and if it is ON, that area. It is a range to maintain ON. The area from the specific area to 3 4 downshift corresponds to the second area 25 in FIG. In this way, it is not necessary to hold the map of the predetermined operating area 23 (see FIG. 5) in the ROM 19b of the controller 19, and the multi-plate brake ON control process (see FIG. 4) can be simplified. (Effect corresponding to claim 2).

Alternatively, when the mechanical transmission 16 of FIG. 1 is a stepless type, the following may be performed. FIG. 9 is a diagram showing another preferred modification of the predetermined operating region 23. In this figure, the vertical axis is the accelerator opening F, and the horizontal axis is the gear ratio of the mechanical continuously variable transmission (the gear ratio calculated from the shift position S output from the mechanical transmission 16 in FIG. 1). The portion indicated by the hatching is the predetermined operating region 23 in which the multi-plate brake 12 is forcibly turned on. According to this example, the accelerator opening F and the gear ratio are checked, and when they are in a predetermined predetermined operating region 23, the multi-plate brake 12 is turned on, so that the multi-plate brake ON control process ( (See Fig. 4) can be simplified (effect corresponding to claim 2).

In the above description, the predetermined operating area 23 is fixedly set, but the present invention is not limited to this. For example, a region frequently used on the accelerator opening F-vehicle speed V plane is estimated from the past combination history of the accelerator opening F and the vehicle speed V, and the predetermined operating region is included so as to include this estimated region. An area changing means for changing 23 (actually, it is a function realized by software with CPU 19a) may be provided. Hereinafter, an example of the means will be described with reference to FIG.

FIG. 10 is a diagram showing still another preferred modification of the predetermined operating region 23. In this figure, the vertical axis is the accelerator opening F and the horizontal axis is the vehicle speed V. The black dots in the figure are the history of combinations of the accelerator opening F and the vehicle speed V that have appeared in the past, and the squares surrounded by the broken lines are the estimation target areas.

In this example, the squares in which the number of black dots is a predetermined value (N) or more is defined as a "frequently used area", that is, a predetermined operating area 23. For example, if N = 3, a total of 8 squares (enclosed by a thick solid line) in the 3rd, 4th, 5th, and 6th rows from the left among the 2nd and 3rd rows from the bottom. Since the number of all black dots in the squares) is equal to or greater than the predetermined value (N), the range of the thick solid line including these eight squares is the frequently used area, and therefore the above-mentioned predetermined operating area. It will be set as 23.

In this way, the size and position of the predetermined driving area 23 can be set to "variable" based on the combination history of the accelerator opening F and the vehicle speed V that have appeared in the past. Control characteristics that match habits and preferences can be obtained, and so-called learning effects can be added to improve control accuracy (effect corresponding to claim 3).

The "history of the combination of the accelerator opening F and the vehicle speed V that appeared in the past" is, for example, sampled at an interval (τ) shorter than that time (T) at a time (T) that goes back from the present to the past. It is a combination of the accelerator opening F and the vehicle speed V. In this case, the interval for resetting the predetermined operation region 23 may be equal to or greater than the sampling interval (τ), and can be arbitrarily set regardless of the time (T).

Further, the predetermined operating region 23 in FIG. 10 may be composed of squares including black dots of a predetermined value (N) or more, and is not limited to the illustrated shape (rectangle). Further, although the shape of each square is a square in the figure, for example, it may be a vertically long or horizontally long rectangle, or another shape (triangle, rhombus, etc.).

Further, the predetermined operating region 23 in FIG. 10 is a single region, but this is simply because the squares including the black dots of the predetermined value (N) or more are adjacent to each other. Naturally, it may be divided into a plurality of regions depending on the positions of the squares including the black dots of the predetermined value (N) or more.

Further, in the above-mentioned area changing means (a function realized by software with the CPU 19a), the position and size of the predetermined driving area 23 are based on the combination history of the accelerator opening F and the vehicle speed V appearing in the past. It is estimated, but it is not limited to this. For example, it acquires information such as the current driving position, the planned driving route in the future, and the traffic conditions on those driving routes, and predicts the appearance frequency of the combination of the accelerator opening F and the vehicle speed V based on the information. Then, the position and size of the predetermined operating area 23 may be estimated. In this case, the current travel position and future travel route can be easily obtained from a so-called car navigation system using GPS (Global Positioning System), and information such as traffic conditions on those travel routes. Can be easily obtained by using, for example, VICS (Vehicle Information and Communication System). Then, by doing so, there is an effect (effect corresponding to claim 5) that the control characteristics according to the actual running state can be obtained. In this case, GPS and VICS are information acquisition means.

Further, the past history is not only the combination of the accelerator opening F and the vehicle speed V, but also the combination of the gear ratio or the gear ratio and the accelerator opening is the same as the combination of the vehicle speed and the accelerator opening. (Effect corresponding to claim 4) can be obtained.

Further, in the above-mentioned area changing means, the determination reference value (number of black dots N) for determining the "frequently used area" is set to a fixed value such as N = 3, but is not limited to this. It may be variably set based on any parameter representing the load of the cooling system.

FIG. 11 is a diagram showing a flowchart when the determination reference value (number of black dots N) is variably set. In this example, as an arbitrary parameter representing the load of the cooling system, for example, the temperature (or temperature) of the internal combustion engine 1 (or The temperature of the engine room) is used. That is, the detection temperature T of the temperature sensor 22 is taken in (step S21), the temperature range to which this temperature T belongs is determined, and the determination reference value (number of black dots N) is variably set based on the determination result. There is. By making the variable setting in this way, more appropriate control becomes possible.

For example, considering the three judgment thresholds T1 to T3 (however, T1 &lt;T2 &lt;T3) included between the minimum and maximum values of the temperature (or engine room temperature) of the internal combustion engine 1, the detection temperature T Is included in any of the "low temperature region" above T1, the "medium temperature region" above T1 and below T2, the "high temperature region" above T2 and below T3, and the "high temperature region" above T3. The relationship between each of these temperature regions and the load of the cooling system is that the load increases as the temperature rises, that is, in the order of "low temperature region" "medium temperature region" "high temperature region" "high temperature region". Since the load increases, the size of the predetermined operating region 23 may be increased according to the order.

In the figure, N1, N2, N3 and N4 are judgment reference values (number of black spots) for each temperature region, and N1&gt; N2&gt; N3&gt; N4. That is, when the low temperature region where T &lt;T1 is determined (YES in step S22), the maximum determination reference value N1 is set to N (step S23), and the medium temperature region where T1 &lt;T &lt;T2 is set. When the judgment (YES in step S24) is made, the next judgment reference value N2 is set to N (step S25), and the high temperature region where T2 &lt;T &lt;T3 is judged (YES in step S26). If this is the case, the next-order judgment reference value N3 is set to N (step S27), and if the high temperature region where T3 &lt;T is judged (NO in step S26), the minimum judgment criterion is set. The value N4 may be set to N (step S28).

FIG. 12 is a diagram showing the size of a predetermined operating region 23 set for each temperature region. In this figure, (a) is set by applying the judgment reference value N1, (b) is set by applying the judgment reference value N2, and (c) is set by applying the judgment reference value N3. The set one, (d) is the one set by applying the judgment reference value N4. The number of sunspots in the squares included in each predetermined operating region 23a to 23d decreases in the order of (a) (b) (c) (d), and therefore the low temperature region medium temperature region. The size of the predetermined operating regions 23a to 23d can be expanded in the order of high temperature region high temperature region. By doing so, more appropriate control can be performed.

In the above example, the temperature of the internal combustion engine 1 (or the temperature of the engine room) is used as an arbitrary parameter representing the load of the cooling system, but the present invention is not limited to this. For example, it is more preferable to use the temperature of the motor (first motor 9 or second motor 11), the outside air temperature, or a combination temperature thereof including the temperature of the internal combustion engine 1 (or the temperature of the engine room). Control is possible.

<figref num="1">It is a conceptual block diagram of this embodiment.</figref><figref num="2">It is a conceptual block diagram of a controller 19.</figref><figref num="3">It is a figure which shows the flowchart of the control program executed by the CPU 19a of a controller 19.</figref><figref num="4">It is a figure which shows the flowchart of "multi-plate brake ON control processing".</figref><figref num="5">It is a conceptual diagram which shows the "predetermined operation area" that the multi-plate brake 12 should be turned from OFF to ON.</figref><figref num="6">It is the figure which plotted the combination of the accelerator opening F and the vehicle speed V in actual driving.</figref><figref num="7">It is a figure which shows the preferable modification of the predetermined operation area 23.</figref><figref num="8">It is a figure which shows the other preferable modification of the predetermined operation area 23.</figref><figref num="9">It is a figure which shows the other preferable modification of the predetermined operation area 23.</figref><figref num="10">It is a figure which shows still another preferable modification of a predetermined operation area 23.</figref><figref num="11">It is a figure which shows the flowchart when the judgment reference value (the number of black dots N) is variably set.</figref><figref num="12">It is a figure which shows the size of the predetermined operation area 23 set for each temperature area.</figref>

Code description

F Accelerator opening S15 Step (judgment means) S16 Step (operating means) V Vehicle speed 1 Internal gear engine 2 Output shaft (output shaft of internal gear engine) 4 Planetary gear mechanism (differential gear device) 5 Carrier (first gear element) 6 Sun gear (second gear element) 8 Ring gear (third gear element) 9 First motor (the other motor of the two types) 9b Output shaft (the other of the two types of motors) Motor output shaft) 11 Second motor (one of the two types of motors) 11b Output shaft (output shaft of one of the two types of motors) 12 Multi-plate brake (fixing means) 16 Machine Type transmission (speed change means) 18 Drive wheels 19a CPU (judgment means, stop means, area changing means) 20 Vehicle speed sensor (vehicle speed detection means) 21 Accelerator opening sensor (accelerator opening detection means) 23 Predetermined operating area (fixed) Means operating area) 23a ~ 23d Predetermined operating area (fixing means operating area)