JP5434532B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a technical field of a control device for a hybrid vehicle that controls a hybrid vehicle including a power transmission mechanism including a rotary element having a backlash in a rotation direction between an internal combustion engine and a rotating electrical machine and a drive shaft.

  As this type of device, a device that suppresses the generation of rattling noise according to the SOC (State Of Charge) of the battery has been proposed (for example, see Patent Document 1). According to the device disclosed in Patent Document 1, when the rattling noise is generated, if there is a margin in the SOC, the engine output is reduced and the drive-side motor generator is powered, and there is no margin in the SOC. In this case, it is said that the rattling noise can be suppressed by increasing the engine output and regenerating the driving motor generator.

  It has also been proposed to control the motor generator as a reaction force element so as to deviate from the conditions for generating rattling noise when in a region where rattling noise is generated when an engine start request or stop request is detected. (For example, refer to Patent Document 2).

JP 2004-328824 A JP 2008-006945 A

  Some hybrid vehicles vary a transmission mode that defines a control mode of a transmission ratio, which is a ratio between the rotational speed of an internal combustion engine and the rotational speed of a drive shaft, in accordance with a fastening state of a predetermined fastening element. In this type of hybrid vehicle, it is not uncommon for the input / output torque of the rotating electrical machine with respect to the drive shaft to straddle the region where the rattling noise is generated when the shift mode is switched.

  On the other hand, at the time of switching of this type of transmission mode, noise is easily generated due to a change in the fastening state of the fastening element. If a rattling sound is generated during such a period, they overlap each other, and the noise is remarkably increased. , The driver may feel uncomfortable.

  However, in the inventions described in each of the above-mentioned patent documents, the overlap between the rattling sound and the noise generated when switching the shift mode is not avoided, so that a sense of incongruity may be given to the driver each time the shift mode is switched. There is sex. In other words, the conventional technique has a technical problem that it is difficult to prevent a decrease in drivability associated with switching of the shift mode.

  The present invention has been made in view of the above-described problems, and provides a hybrid vehicle control device capable of preventing a decrease in drivability due to rattling noise at the time of shift mode switching. Let it be an issue.

  In order to solve the above-described problem, a control apparatus for a hybrid vehicle according to the present invention includes an internal combustion engine, a rotating electrical machine, a power storage unit that can supply power to the rotating electrical machine and can be charged by regenerative power of the rotating electrical machine. A power transmission mechanism comprising a plurality of rotating elements each having play in the rotational direction, and configured to transmit torque between a drive shaft connected to an axle and the internal combustion engine and the rotating electrical machine; A locking means capable of selectively switching the state of one of the rotating elements between a non-rotatable locked state and a rotatable unlocked state, corresponding to the non-locked state, the internal combustion engine Between a continuously variable transmission mode in which the transmission gear ratio between the rotational speed of the engine and the rotational speed of the drive shaft is continuously variable, and a fixed transmission mode in which the transmission gear ratio is fixed corresponding to the locked state. With shift mode A hybrid vehicle configured to be able to switch a mode, wherein the input / output torque of the rotating electrical machine with respect to the drive shaft converges to a target torque during the shift mode switching period. Determining means for determining whether or not to cross the avoidance area set to generate rattling noise caused by rattling, and when it is determined that the input / output torque straddles the avoidance area, And a control means for controlling the input / output torque so that a switching period and a period in which the input / output torque crosses the avoidance region do not overlap.

  In the hybrid vehicle according to the present invention, as a power element capable of supplying power to the drive shaft, the physical, mechanical, or fuel type, fuel supply mode, fuel combustion mode, intake / exhaust system configuration, cylinder arrangement, etc. Rotation of an internal combustion engine as an engine capable of generating power by burning fuel and various motor generators capable of powering and power generation (that is, power regeneration) that can take various modes regardless of electrical configuration Electric. The rotating electrical machine regenerates input power as electric power in the positive rotation region, for example, when power is input through a power transmission path that sequentially passes through the drive wheels, the axle, and the drive shaft (that is, negative torque). Is possible.

  Further, the hybrid vehicle according to the present invention can transmit torque between the internal combustion engine and the rotating electric machine as the power elements and the drive shaft directly connected to the axle or indirectly connected through various gear mechanisms. A power transmission mechanism is provided. The power transmission mechanism has a plurality of rotating elements (preferably gears), and each of the plurality of rotating elements has a backlash in the rotation direction thereof.

  The rotation element constituting the power transmission mechanism includes, as a preferred embodiment, a first rotation element, a second rotation element connected to the drive shaft, and a third rotation element connected to the internal combustion engine, In addition, it may be configured to be able to perform a differential action. In this case, depending on the state of each rotating element (including whether or not it is rotatable and whether it is connected to another rotating element or a fixed element, etc.) due to such differential action. In addition, torque transmission between the power element and the drive shaft may be possible. In this case, the power transmission mechanism may include one or a plurality of various differential gear mechanisms such as a planetary gear mechanism. In the case of including a plurality of planetary gear mechanisms, a part of the rotating element constituting each planetary gear mechanism can be appropriately shared between the plurality of planetary gear mechanisms.

  When the power transmission mechanism is constructed as a kind of differential mechanism as described above, the hybrid vehicle may include other rotating electrical machines in addition to the rotating electrical machine according to the present invention. The other rotating electrical machine may function as, for example, a reaction force element that gives a reaction torque to the internal combustion engine. In this case, the operating point of the internal combustion engine is at least within a certain range by the other rotating electrical machine. Can be continuously variable. In this case, as the engine torque of the internal combustion engine, a direct torque corresponding to the reaction torque is transmitted to the drive shaft, and the input / output torque (input torque between the rotating electrical machine and the drive shaft according to the present invention is: , Corresponding to power regeneration) and the direct torque, the drive shaft torque may be defined.

  In a configuration including a plurality of rotating electrical machines, one rotating electrical machine does not necessarily function as a reaction force element. Depending on the configuration of the rotating elements of the power transmission mechanism, one of the plurality of rotating electrical machines may be a reaction force element. Alternatively, it is possible to function as a driving element and to function the other as a driving element or a reaction force element. In such a configuration, the rotating electrical machine according to the present invention may mean a rotating electrical machine on the side that functions as a driving element at that time.

  On the other hand, the hybrid vehicle according to the present invention includes a lock mechanism. The lock mechanism determines the state of one of the rotating elements included in the power transmission mechanism, for example, various physical, mechanical, electrical or magnetic engagement forces (for example, hydraulic engagement force or electromagnetic engagement force). Etc.) between the non-rotatable locked state fixed to the predetermined fixing element in a non-rotatable state and the rotatable non-locked state at least substantially unaffected by the engagement force relating to this locked state. It is a switchable device. The lock mechanism may take various forms such as a wet multi-plate brake device or a clutch device, an electromagnetic dog clutch device, or an electromagnetic cam lock type clutch device.

  On the other hand, the hybrid vehicle according to the present invention is configured so that the shift mode can be selectively switched between the continuously variable transmission mode and the fixed transmission mode by the action of the lock mechanism, and the rotation element to be locked is The fixed transmission mode is selected in the locked state, and the continuously variable transmission mode is selected in the state where the rotation element to be locked is released (unlocked state).

  More specifically, the continuously variable transmission mode is a reaction force element when, for example, the hybrid vehicle includes a plurality of rotating electric machines as described above, and the power transmission mechanism is configured as a differential mechanism with two degrees of rotation, for example. By making the rotating electrical machine function as a rotational speed control mechanism of the internal combustion engine, a gear ratio as a ratio between the rotational speed of the internal combustion engine and the rotational speed of the drive shaft is theoretically, substantially or physically defined in advance, Even if it is defined as a shift mode that can be changed continuously (including a stepped manner equivalent to being practically continuous) within the limits of mechanical, mechanical, or electrical restrictions. Good.

  In this case, as a preferred embodiment, the operating point of the internal combustion engine (for example, a point defining one operating condition of the internal combustion engine defined by the engine speed and torque) is, for example, theoretically, substantially or It is freely selected within a range of constraints, for example, the fuel consumption rate is theoretically, substantially or minimally within a range of constraints, or the system efficiency of the hybrid vehicle (for example, the transmission efficiency of the power transmission mechanism and the internal combustion engine). The total efficiency calculated based on the thermal efficiency of the engine or the like) can theoretically be controlled to an optimum fuel consumption operating point or the like that is substantially or maximum within a range of some constraints.

  On the other hand, in the fixed speed change mode, when considering a differential mechanism having two degrees of freedom of rotation, the speed ratio realized by maintaining the rotation element to be locked in the locked state is uniquely defined. This is a shift mode. That is, when the rotation element is in the locked state, the rotation speed (that is, zero) of the rotation element to be locked and the rotation of the rotation element (rotation element connected to the drive shaft) that is uniquely defined by the vehicle speed. Depending on the speed, the rotational speed of the remaining rotary elements is uniquely defined, and the rotational speed of the internal combustion engine can be converged to this uniquely defined value.

  The hybrid vehicle control device according to the present invention is a control device that controls such a hybrid vehicle, and includes, for example, one or a plurality of CPUs (Central Processing Units), MPUs (Micro Processing Units), various processors, or various controllers. Alternatively, various processing units such as a single or plural ECUs (Electronic Controlled Units), which may appropriately include various storage means such as ROM (Read Only Memory), RAM (Random Access Memory), buffer memory or flash memory Various computer systems such as various controllers or microcomputer devices can be used.

  Here, since the power transmission mechanism is disposed in the power transmission path between the internal combustion engine and the drive shaft, the power transmission mechanism is exposed to physical vibrations of various sizes, large and small, using the internal combustion engine as a vibration source. On the other hand, since the rotating elements of the power transmission mechanism have backlash, such as backlash, in the rotation direction, if these rotating elements vibrate with an amplitude corresponding to the backlash due to the physical vibration, teeth that are difficult to ignore in practice. A hitting sound may occur. Such rattling noise can be a factor that significantly reduces the drivability of the vehicle.

  Therefore, the input / output torque of the rotating electrical machine according to the present invention (that is, the rotating electrical machine as a driving element) is low enough to generate this kind of rattling noise (that is, not high enough to suppress the physical vibration). In this case, a rotating element in the vicinity of this rotating electrical machine (of course, not necessarily limited to the vicinity of the rotating electrical machine, but various types depending on the configuration of the power transmission mechanism) etc. vibrates in the range of backlash, A rattling noise may occur. In the present invention, the region of the input / output torque of the rotating electrical machine where the rattling noise can be generated is referred to as an avoidance region. The avoidance region is a region straddling the positive torque side and the negative torque side across the zero torque.

  On the other hand, in practical operation, for example, when the rotating electrical machine functions as an auxiliary power element, the target torque that is the target value of the input / output torque of the rotating electrical machine is the driver as the torque required for the drive shaft. It is often set according to the magnitude relationship between the required torque and the engine torque of the internal combustion engine (or the direct torque as a component acting on the drive shaft of the engine torque). It is not uncommon for torque to cross the avoidance region. Note that “the target torque crosses the avoidance region” preferably includes that the target torque is set in the other torque region sandwiching the avoidance region when the target torque is in one torque region sandwiching the avoidance region. This is intended to include that the target torque is set from the one torque region to the avoidance region (that is, the target torque stays in the avoidance region). That is, “the target torque straddles the avoidance region” is not necessarily limited to the category generally recalled from the phrase “straddle”.

  On the other hand, such a situation in which the input / output torque straddles the avoidance region can be conspicuous at the time of switching the shift mode in which the driver request torque tends to be relatively small. However, since the shift mode switching involves the physical action of the lock mechanism, it can itself be accompanied by noise. Although such noise may vary depending on the physical configuration of the lock mechanism, there is basically no change in the noise that occurs when the shift mode is switched. That is, when switching the transmission mode, the noise resulting from the switching of the transmission mode itself and the rattling noise generated in the power transmission mechanism overlap, and drivability is likely to be significantly reduced.

  Therefore, the hybrid vehicle control device according to the present invention suppresses a decrease in drivability when the transmission mode is switched as follows.

  That is, according to the control apparatus for a hybrid vehicle according to the present invention, during the operation, the avoidance area is firstly determined in the process where the input / output torque of the rotating electrical machine with respect to the drive shaft converges to the target torque during the shift mode switching period. It is determined whether or not to cross. At this time, the determination means, for example, the driver request torque at that time, the state quantity corresponding to the power storage state of the power storage means (preferably, for example, the fully charged state is 100 (%) and the fully discharged state is 0 (%), etc. It indicates the SOC (State Of Charge) as a quantitative indicator of the state of charge (note that the SOC is also used as a word meaning the state of charge itself) or required when changing the shift mode. It is possible to make such a determination based on the adjustment torque that is applied (in short, the torque that compensates for the variation in the direct torque when the reaction force element is switched) or the like.

  Supplementally, whether or not the input / output torque crosses the avoidance region during the shift mode switching period has various properties depending on the state of each part of the hybrid vehicle, the driving conditions, and the like. For example, the rotating electrical machine operates in the positive torque region at the time of switching from the fixed transmission mode to the continuously variable transmission mode, at the time of switching from the continuously variable transmission mode to the fixed transmission mode, or when a transmission mode switching request occurs. This type of avoidance region straddling can occur both when the vehicle is operating and when operating in the negative torque region.

  According to the control apparatus for a hybrid vehicle of the present invention, when it is determined that the input / output torque of the rotating electrical machine crosses the avoidance region during the shift mode switching period during the operation, the control means The input / output torque of the rotating electrical machine is controlled so that the mode switching period and the period in which the input / output torque of the rotating electrical machine crosses the avoidance region do not overlap.

  That is, in this case, a predetermined standard (for example, a control logic for maintaining the state quantity of the above-described power storage means at a reference value, a control logic for maximizing the system efficiency of the hybrid vehicle, or an internal combustion engine) Basically, the input / output torque is converged to the original target torque set based on the control logic for matching the sum of the directly achieved engine torque and the input / output torque of the rotating electrical machine to the driver request torque. Convergence control is temporarily invalidated, and the timing when the input / output torque starts to change toward the original target torque by the control means is the timing before the start of the shift mode switching or after the shift mode switching is completed. The timing is shifted to. Therefore, it is possible to reliably prevent the noise accompanying the switching of the shift mode and the noise caused by the input / output torque straddling the avoidance region from being overlapped, and the drivability can be reliably suppressed from decreasing. It is.

  That is, the present invention obtains a time delay until the duplication of noise that causes a decrease in drivability occurs by predicting that the target torque of the rotating electrical machine crosses the avoidance region during the shift mode switching period. It is possible to prevent noise duplication reliably by using the technical idea that the timing at which the input / output torque crosses the avoidance area is shifted on the time axis using the acquired time delay. It is a thing. Therefore, there is a possibility that the rattling noise caused by the input / output torque straddling the avoidance area and the noise caused by the change of the shift mode overlap due to the change of the input / output torque at the timing left to the end in the shift mode change period. There is a clear advantage over traditional technical ideas that cannot be excluded.

  In one aspect of the control apparatus for a hybrid vehicle according to the present invention, the control means includes the engine torque supplied from the internal combustion engine and the input / output so that the driver request torque required for the drive shaft is maintained. Coordinate control with torque.

  According to this aspect, for example, when the input / output torque is higher than the target torque in the process of controlling the timing at which the input / output torque crosses the avoidance region, the engine torque of the internal combustion engine decreases due to the action of the control means. If the torque is low, the engine torque is corrected to the increase side, and the driver required torque required for the drive shaft is maintained. Therefore, it is possible to prevent the driver from feeling uncomfortable such as torque shock during the execution of the control related to noise suppression, and it is more effective in suppressing the drivability deterioration.

In another aspect of the hybrid vehicle control device according to the present invention, the straddling time is shortened as the time required for the input / output torque to cross the avoidance region, and the straddling time is not shortened. In some cases, it further comprises shortening means for shortening the reference time as the time required for the input / output torque to cross the avoidance region.

  According to this aspect, the shortening means reduces the straddling time as the time required for the input / output torque to actually straddle the avoidance region. For this reason, it becomes possible to suppress the occurrence of rattling noise that occurs when the input / output torque crosses the avoidance region, which is more effective in suppressing drivability deterioration.

  Here, the “reference time” that gives a reference for shortening the straddling time means that the input / output torque straddles the torque region having a width corresponding to the avoidance region when the input / output torque does not straddle the avoidance region. In other words, it is the time required to straddle the avoidance area under normal control conditions. That is, the meaning of the shortening means is to apply special torque control specialized for the case where the avoidance area is crossed over to the input / output torque, and the actual shortening time is calculated by the shortening means. The practical aspect is not limited in any way as long as the time (reference time) required when not shortening can be shortened considerably.

  Supplementally, even if it is said that the reference time is a time to be assigned, there is naturally a control reference that defines this reference time. For example, if the current input / output torque and target torque are determined, the drive conditions of the rotating electrical machine are determined according to various control terms such as feedback gain of torque feedback control, and the time required to reach the target torque is fixed to some extent. To do. In this case, for example, if the target torque is set on the side where the torque deviation is larger than the original target torque, or if the feedback gain is corrected so that the input / output torque converges to the target torque earlier, etc. The effect of clearly shortening the crossing time with respect to the reference time can be obtained.

  In this aspect, the target torque is such that the magnitude of the reference deviation, which is the deviation between the state quantity corresponding to the power storage state of the power storage means and the reference value of the state quantity, corresponds to the magnitude of the target torque, respectively. The shortening means is set according to the reference deviation, and the shortening means temporarily stops the setting of the target torque according to the reference deviation and maintains the input / output torque in a torque region outside the avoidance region. The straddling time may be shortened by increasing the reference deviation and restarting the setting of the target torque according to the reference deviation after the reference deviation is increased.

  According to this aspect, the target torque of the input / output torque is set according to the reference deviation that is the deviation between the state quantity (preferably means the above-described SOC) corresponding to the storage state of the storage means and the reference value. The state quantity feedback control is executed. When shortening the crossing time, the shortening means temporarily stops the target torque setting according to the reference deviation, that is, the feedback control of the state quantity of the power storage means, and the input / output torque is torque outside the avoidance area. Let the area maintain.

  Since the reference deviation increases when the input / output torque is maintained in the torque area outside the avoidance area in this way, the deviation between the target torque set after the restart of the feedback control and the current input / output torque is this kind of measure. Compared to the case where the problem is not taken, the power supply amount for driving the rotating electrical machine is inevitably increased, and the time for passing through the avoidance region is shortened. Thus, if the feedback control of the state quantity of the power storage means, which is a part of the existing control process, is used, the control load of the shortening means is reduced.

  Note that the mode in which the feedback control is temporarily stopped is not uniquely limited. For example, the reference value may be set to the current state quantity (that is, the deviation becomes zero), or the feedback control itself is stopped. May be.

  In another aspect of the hybrid vehicle control device according to the present invention, the control means has a predetermined amount of state corresponding to the power storage state of the power storage means when the input / output torque crosses the avoidance area from the positive torque area. When it is higher than the reference value, the input / output torque is controlled so as to cross the avoidance region after the shift mode is switched.

  According to this aspect, when the input / output torque crosses the avoidance region from the positive torque region, the state quantity corresponding to the power storage state of the power storage means is a reference value (a value different from the reference value in the feedback control described above). If it is higher than (good), priority is given to switching the shift mode. In this way, when priority is given to switching of the shift mode, the engine torque of the internal combustion engine during the shift mode switching period is set to be lower than the original required torque, and the input / output torque is maintained at a positive torque.

  Therefore, the effect of reducing the state quantity of the power storage means in the direction of the reference value can be obtained. In addition, in this case, it is not necessary to change the input / output torque when the shift mode change request is issued again after the shift mode change is completed, and the input / output torque is avoided. It is possible to reduce the frequency of crossing the region. That is, it is advantageous in terms of drivability.

  In another aspect of the hybrid vehicle control device according to the present invention, the control means has a predetermined amount of state corresponding to the power storage state of the power storage means when the input / output torque crosses the avoidance area from the positive torque area. When the value is lower than the reference value, the input / output torque is controlled so as to cross the avoidance area prior to switching the shift mode.

  According to this aspect, when the input / output torque crosses the avoidance region from the positive torque region, the state quantity corresponding to the power storage state of the power storage means is a reference value (a value different from the reference value in the feedback control described above). If it is lower than (good), priority is given to the input / output torque avoidance region straddling. In this way, when priority is given to the input / output torque crossing over the avoidance area, the engine torque of the internal combustion engine during the shift mode switching period is set to be higher than the original required torque, and excess torque is set by the input / output torque. By absorbing, the input / output torque is switched to the negative torque side.

  Therefore, it becomes difficult to control the rotating electrical machine due to deterioration of the power storage state of the power storage means during the shift mode switching period, or it becomes difficult to secure input / output torque (pressing torque) required for switching the shift mode. The situation is prevented and it is advantageous in terms of fail-safe.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

1 is a schematic configuration diagram conceptually illustrating a configuration of a hybrid vehicle according to a first embodiment of the present invention. FIG. 2 is a schematic configuration diagram conceptually showing a configuration of a hybrid drive device in the hybrid vehicle of FIG. 1. FIG. 3 is an operation alignment chart illustrating one operation state of the hybrid drive device of FIG. 2. 2 is a flowchart of a rattling noise suppression control executed by an ECU in the hybrid vehicle of FIG. It is a flowchart of the rattling sound suppression process performed in the rattling noise suppression control of FIG. It is another flowchart of the other rattling noise suppression process performed in the rattling noise suppression control of FIG. FIG. 5 is a schematic diagram illustrating the MG2 torque Tm and the engine request output Pne over time during the execution process of the rattling noise suppression control of FIG. 4. FIG. 5 is a schematic diagram illustrating another time transition of the MG2 torque Tm and the engine request output Pne in the execution process of the rattling noise suppression control of FIG. 4. FIG. 5 is a schematic view illustrating a one-hour transition of battery SOC and MG2 torque Tm in the execution process of the rattling noise suppression control of FIG. 4. FIG. 6 is a schematic configuration diagram conceptually showing the configuration of another hybrid drive apparatus according to the second embodiment of the present invention. FIG. 10 is a schematic configuration diagram conceptually illustrating a configuration of another hybrid drive device according to a third embodiment of the present invention.

<Embodiment of the Invention>
Embodiments of the present invention will be described below with reference to the drawings.

<Configuration of Embodiment>
First, with reference to FIG. 1, the structure of the hybrid vehicle 1 which concerns on one Embodiment of this invention is demonstrated. FIG. 1 is a schematic configuration diagram conceptually showing the configuration of the hybrid vehicle 1.

  In FIG. 1, the hybrid vehicle 1 includes an ECU 100, a PCU (Power Control Unit) 11, a battery 12, an accelerator position sensor 13, a vehicle speed sensor 14, and a hybrid drive device 10 according to the present invention. It is.

  The ECU 100 is an electronic control unit that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM, and the like, and is configured to be able to control the operation of each part of the hybrid vehicle 1. It is an example of a “control device for a hybrid vehicle”. The ECU 100 is configured to be able to execute a rattling noise suppression control described later according to a control program stored in the ROM. The ECU 100 is an integrated electronic control unit configured to function as an example of each of the “discriminating means”, “control means”, and “shortening means” according to the present invention. , All are configured to be executed by the ECU 100. However, the physical, mechanical, and electrical configurations of each of the units according to the present invention are not limited to this. For example, each of these units includes a plurality of ECUs, various processing units, various controllers, a microcomputer device, and the like. It may be configured as various computer systems.

  The hybrid drive device 10 drives the hybrid vehicle 1 by supplying driving torque as driving force to the left axle SFL (corresponding to the left front wheel FL) and the right axle SFR (corresponding to the right front wheel FR), which are the axles of the hybrid vehicle 1. Drive unit. The detailed configuration of the hybrid drive device 10 will be described later.

  The PCU 11 converts the DC power extracted from the battery 12 into AC power and supplies it to a motor generator MG1 and a motor generator MG2, which will be described later, and also converts AC power generated by the motor generator MG1 and the motor generator MG2 into DC power. Inverter (not shown) configured to be supplied to the battery 12, and the power input / output between the battery 12 and each motor generator, or the power input / output between the motor generators (that is, In this case, the control unit is configured to be capable of controlling power transfer between the motor generators without using the battery 12. The PCU 11 is electrically connected to the ECU 100, and its operation is controlled by the ECU 100.

  The battery 12 has a configuration in which a plurality of unit battery cells are connected in series, and is a battery unit that functions as a power supply source related to power for powering the motor generator MG1 and the motor generator MG2. It is an example of “means”.

  The accelerator opening sensor 13 is a sensor configured to be able to detect an accelerator opening Ta that is an operation amount of an accelerator pedal (not shown) of the hybrid vehicle 1. The accelerator opening sensor 13 is electrically connected to the ECU 100, and the detected accelerator opening Ta is referred to by the ECU 100 at a constant or indefinite period.

  The vehicle speed sensor 14 is a sensor configured to be able to detect the vehicle speed V of the hybrid vehicle 1. The vehicle speed sensor 14 is electrically connected to the ECU 100, and the detected vehicle speed V is referred to by the ECU 100 at a constant or indefinite period.

  Here, the detailed configuration of the hybrid drive apparatus 10 will be described with reference to FIG. FIG. 2 is a schematic configuration diagram conceptually showing the configuration of the hybrid drive apparatus 10. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof will be omitted as appropriate.

  In FIG. 2, the hybrid drive device 10 includes an engine 200, a power split mechanism 300, a motor generator MG1 (hereinafter appropriately referred to as “MG1”), a motor generator MG2 (hereinafter appropriately referred to as “MG2”), an input shaft. 400, a lock mechanism 500, an MG2 reduction mechanism 600, and a speed reduction mechanism 700.

  The engine 200 is an in-line four-cylinder gasoline engine that is configured to function as a main power source of the hybrid vehicle 1 and that is an example of the “internal combustion engine” according to the present invention. The engine 200 is a known gasoline engine, and a detailed configuration thereof is omitted here, but the engine torque Te, which is the output power of the engine 200, is input to the input shaft 400 of the hybrid drive apparatus 10 via a crankshaft (not shown). It is connected to. The engine 200 is merely an example of a practical aspect that can be adopted by the internal combustion engine according to the present invention. The practical aspect of the internal combustion engine according to the present invention is not limited to the engine 200, and various known engines can be employed. It is.

  Motor generator MG1 is a motor generator having a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy.

  The motor generator MG2 is a motor generator that is an example of the “rotary electric machine” according to the present invention and is larger than the motor generator MG1, and, like the motor generator MG1, has a power running function that converts electrical energy into kinetic energy, It has a configuration with a regenerative function that converts kinetic energy into electrical energy.

  Motor generators MG1 and MG2 are configured as synchronous motor generators, and include, for example, a rotor having a plurality of permanent magnets on the outer peripheral surface and a stator wound with a three-phase coil that forms a rotating magnetic field. Of course, other configurations may be used.

  The power split mechanism 300 is a composite planetary gear mechanism that is an example of the “power transmission mechanism” according to the present invention.

  The power split mechanism 300 includes a sun gear S1 as an example of a “rotating element” according to the present invention provided in the center, and a “rotating element” according to the present invention concentrically provided on the outer periphery of the sun gear S1. An example of the ring gear R1, a plurality of pinion gears (not shown) that are arranged between the sun gear S1 and the ring gear R1 and revolve while rotating on the outer periphery of the sun gear S1, and the rotation shafts of these pinion gears And a carrier C1 which is still another example of the “rotating element” according to the present invention.

  Here, the sun gear S1 is coupled to the rotor of the motor generator MG1 so as to share the rotation axis thereof, and the rotation speed thereof is equivalent to the MG1 rotation speed Nmg1 that is the rotation speed of the MG1. The ring gear R1 is connected to a ring gear R2 described later of the speed reduction mechanism 700 and the MG2 reduction mechanism 600, and the rotation speed thereof is equivalent to the output rotation speed Nout that is the rotation speed of the drive shaft. Further, the carrier C1 is connected to an input shaft 400 that is connected to the crankshaft of the engine 200, and the rotational speed thereof is equivalent to the engine rotational speed NE of the engine 200.

  The MG2 reduction mechanism 600 is a planetary gear mechanism similar to the power split mechanism 300. The MG2 reduction mechanism 600 is disposed between the sun gear S2 provided at the center, the ring gear R2 provided concentrically on the outer periphery of the sun gear S2, and between the sun gear S2 and the ring gear R2. A plurality of pinion gears (not shown) that revolve while rotating on the outer periphery, and a carrier C2 that supports the rotation shaft of each pinion gear, and the rotor of the motor generator MG2 is connected to the sun gear S2. Have.

  Here, the ring gear R2 of the MG2 reduction mechanism 600 is connected to the ring gear R1 of the power split mechanism 300 as described above, and exhibits an unambiguous rotational state with respect to the axle. The carrier C2 is fixed to the fixing element so as not to rotate. Accordingly, the motor generator MG2 fixed to the sun gear S2 that is the remaining one rotation element has a form in which the rotation of the drive shaft is decelerated according to the reduction ratio determined according to the gear ratio of each gear constituting the MG2 reduction mechanism 600. Communicated in In addition, the MG2 reduction mechanism 600 is a simple reduction gear mechanism as described above, and the composite planetary gear mechanism defined by the MG2 reduction mechanism 600 and the power split mechanism 300 constructs a differential mechanism with two degrees of rotation. The MG2 rotational speed Nmg2 that is the rotational speed of the motor generator MG2 is unique according to the vehicle speed V.

  The speed reduction mechanism 700 is a gear mechanism that includes a drive shaft (not shown) that exhibits a rotational state that is unambiguous with the axle, a reduction gear (not shown) connected to the drive shaft, and a differential (not shown). By the speed reduction mechanism 700, the rotational speed of each axle is transmitted to the drive shaft while being decelerated according to a predetermined gear ratio. As described above, the ring gear R1 and the ring gear R2 are connected to the drive shaft, and each ring gear has a structure that is uniquely rotated with the vehicle speed V.

  Unlike motor generator MG1 and engine 200, motor generator MG2 can apply MG2 torque Tm2, which is its output torque, to the drive shaft. Therefore, motor generator MG2 can assist the traveling of hybrid vehicle 1 by applying torque to the drive shaft, or can perform power regeneration by inputting torque from the drive shaft. The MG2 torque Tm, which is the input / output torque of the motor generator MG2, is controlled by the ECU 100 via the PCU 11 together with the MG1 torque Tg, which is the input / output torque of the motor generator MG1.

  In the hybrid drive device 10, a rotation sensor such as a resolver is attached to a portion corresponding to the broken line frames A1 and A2 in the drawing, and the rotation speed of the detection portion can be detected. These rotation sensors are in a state of being electrically connected to the ECU 100, and the detected rotation speed is sent to the ECU 100 at a constant or indefinite period. Supplementally, the rotational speed of the part corresponding to the illustrated broken line frame A1 is MG2 rotational speed Nmg2, and the rotational speed of the part corresponding to the illustrated broken line frame A2 is MG1 rotational speed Nmg1.

  In the power split mechanism 300, the engine torque Te supplied from the engine 200 to the input shaft 400 is transferred to the sun gear S1 and the ring gear R1 by the carrier C1 with the predetermined ratio (the gear ratio between the gears). It is possible to divide the power of the engine 200 into two systems. At this time, in order to make the operation of the power split mechanism 400 easy to understand, when the gear ratio ρ as the number of teeth of the sun gear S1 with respect to the number of teeth of the ring gear R1 is defined, the engine torque Te is applied from the engine 200 to the carrier C1. In this case, the torque Tes acting on the sun gear S1 is expressed by the following equation (1), and the engine direct torque Ter appearing on the drive shaft is expressed by the following equation (2).

Tes = −Te × ρ / (1 + ρ) (1)
Ter = Te × 1 / (1 + ρ) (2)
The configuration of the embodiment relating to the “power transmission mechanism” according to the present invention is not limited to that of the power split mechanism 300. For example, the power transmission mechanism according to the present invention may be a composite planetary gear mechanism in which a plurality of planetary gear mechanisms are combined.

  The lock mechanism 500 is a known wet multi-plate clutch mechanism that is an example of the “lock means” according to the present invention. Lock mechanism 500 includes a first clutch plate connected to the rotation shaft of motor generator MG1 and a second clutch plate connected to a fixed element. The engagement state of these clutch plates is not shown. It is configured to be controlled by a hydraulic control mechanism. At this time, when the clutch plates are engaged with each other, the motor generator MG1 is locked so as not to rotate, and a so-called MG1 lock state is realized. On the other hand, in a state where these clutch plates are released, motor generator MG1 can freely rotate. Motor generator MG1 is connected to sun gear S1 of power split device 300, and locking motor generator MG1 is equivalent to locking sun gear S1. That is, when the clutch plates of the lock mechanism 500 are engaged with each other, the sun gear S1 is in a locked state according to the present invention, and when the clutch plates are released, the sun gear S1 is in an unlocked state according to the present invention.

  The lock mechanism 500 is merely an example of a practical aspect that the lock means according to the present invention can take, and the lock means according to the present invention is, for example, another engagement device such as an electromagnetic dog clutch mechanism or an electromagnetic cam lock mechanism. May be.

<Operation of Embodiment>
<Details of shift mode>
The hybrid vehicle 1 according to the present embodiment can select a fixed transmission mode and a continuously variable transmission mode as an example of the transmission mode according to the present invention, depending on the state of the sun gear S1 of the power split mechanism 300 to be locked. .

  Here, the shift mode of the hybrid vehicle 1 will be described with reference to FIG. Here, FIG. 3 is an operation alignment chart illustrating one operation state of the hybrid drive apparatus 10. In the figure, the same reference numerals are given to the same portions as those in FIG. 2, and the description thereof will be omitted as appropriate.

  In FIG. 3A, the vertical axis represents the rotation speed, and the horizontal axis represents the motor generator MG1 (uniquely sun gear S1), engine 200 (uniquely carrier C1), and motor generator MG2 (in order from the left). The drive shaft is uniquely represented.

  Here, the power split mechanism 300 is a planetary gear mechanism having two rotational degrees of freedom constituted by a plurality of rotating elements having a differential relationship with each other, and the rotation of two elements of the sun gear S1, the carrier C1, and the ring gear R1. When the speed is determined, the rotational speed of the remaining one rotation element is inevitably determined. That is, on the operation collinear diagram, the operation state of each rotary element can be represented by one operation collinear line corresponding to one operation state of the hybrid drive device 10 on a one-to-one basis.

  In FIG. 3A, it is assumed that the operating point of the motor generator MG2 that is uniquely related to the vehicle speed V and the output rotational speed Nout is the operating point m1. In this case, if the operating point of motor generator MG1 is operating point g1, the operating point of engine 200 connected to carrier C1, which is the remaining rotating element, is operating point e1. At this time, if the operating point of the motor generator MG1 is changed to the operating point g2 and the operating point g3 while maintaining the output rotational speed Nout that is the rotational speed of the drive shaft, the operating point of the engine 200 is the operating point e2 and the operating point, respectively. It changes to e3.

  That is, in this case, the engine 200 can be operated at a desired operating point by causing the motor generator MG1 to function as a rotation speed control mechanism. The speed change mode corresponding to this state is the continuously variable speed change mode. In the continuously variable transmission mode, the operating point of the engine 200 (the operating point in this case means one operating condition of the engine 200 defined by the combination of the engine rotational speed NE and the engine torque Te) basically. The fuel consumption rate of engine 200 is controlled to the optimum fuel consumption operating point.

  Here, in the continuously variable transmission mode, of course, the MG1 rotational speed Nmg1 needs to be variable. Therefore, when the continuously variable transmission mode is selected, the driving state of the lock mechanism 500 is controlled so that the sun gear S1 is in the unlocked state.

  In the power split mechanism 300, in order to supply the torque Ter corresponding to the engine torque Te described above to the drive shaft, the rotation shaft of the sun gear S1 according to the engine torque Te (here, "sun gear shaft" for convenience) It is necessary to supply, from the motor generator MG1 to the sun gear shaft, a reaction force torque which is equal in magnitude to the above-described torque Tes appearing in (1) and whose sign is reversed (that is, a negative torque). In this case, at the operating point in the positive rotation region such as the operating point g1 or the operating point g2, MG1 is in a power regeneration state (that is, a power generation state) with a positive rotational negative torque. As described above, in the continuously variable transmission mode, part of the engine torque Te distributed to the sun gear shaft while supplying a part of the engine torque Te to the drive shaft by causing the motor generator MG1 to function as a reaction force element. Power regeneration (power generation) is performed at When the torque required for the drive shaft 600 (that is, the required torque of the hybrid vehicle 1) is insufficient due to the direct torque from the engine 200, the regenerative power is used or power is appropriately supplied from the battery 12. The MG2 torque Tm as an assist torque is appropriately supplied from the motor generator MG2 to the drive shaft.

  On the other hand, for example, when driving at a high speed and a light load, for example, in an operating condition where the engine rotational speed Ne is low for a high output rotational speed Nout, MG1 is an operating point in the negative rotational region such as the operating point g3. . Since motor generator MG1 outputs a negative torque as a reaction torque of engine torque Te, in this case, MG1 enters a state of negative rotation negative torque and enters a power running state. That is, in this case, MG1 torque Tg, which is input / output torque of motor generator MG1, is transmitted to the drive shaft as drive torque of hybrid vehicle 1.

  On the other hand, in the hybrid drive device 10, the engines 200, MG1, and MG2 are controlled in a coordinated manner so that the sum of the engine direct torque Ter and the MG2 torque Tm matches the driver request torque. When MG1 falls into a power running state, motor generator MG2 is in a negative torque state because it absorbs excessive torque with respect to the required torque supplied to the drive shaft. In this case, motor generator MG2 is in a positive rotation negative torque state and is in a power regeneration state. In such a state, an inefficient electric path called so-called power circulation, in which the driving force from MG1 is used for power regeneration in MG2 and MG1 is driven by this regenerative power, is generated. . In the state where the power circulation occurs, the system efficiency of the hybrid drive device 10 decreases.

  Therefore, in the hybrid vehicle 1, the sun gear S <b> 1 is controlled to be locked by the lock mechanism 500 in an operation region that is determined in advance as the power circulation can occur. This is shown in FIG. When the sun gear S1 shifts to the locked state by the lock mechanism 500, the operating point of the motor generator MG1 is fixed to the illustrated operating point g4 corresponding to zero rotation speed.

  In this case, the remaining engine rotation speed Ne is uniquely fixed by the output rotation speed Nout and the zero rotation, and its operating point is e4 in the figure. That is, when the sun gear S1 is locked, the engine rotational speed Ne is uniquely determined by the vehicle speed V and the unambiguous MG2 rotational speed Nmg2 (that is, the gear ratio is constant). The shift mode corresponding to this state is the fixed shift mode.

  In the fixed speed change mode, the reaction torque of the engine torque Te that should be borne by the motor generator MG1 can be replaced by the physical engagement force of the lock mechanism 500. That is, in this case, it is not necessary to control motor generator MG1 in both the power regeneration state and the power running state, and motor generator MG1 can be stopped. Therefore, basically, there is no need to operate motor generator MG2, and MG2 is in an idling state. Eventually, in the fixed speed change mode, the drive torque that appears on the drive shaft is only the direct torque Ter that is divided on the drive shaft side by the power split mechanism 300 out of the engine torque Te. The transmission efficiency is improved.

  In the fixed speed change mode, motor generator MG2 does not necessarily have to be stopped. For example, the hybrid vehicle 1 is provided with various electric auxiliary devices, and appropriate electric power is required to drive the electric auxiliary devices. The motor generator MG2 may perform small-scale power regeneration in order to supply the battery 12 with power corresponding to the driving power. In this case, ECU 100 controls engine torque Te so that the directly achieved portion of engine torque Te is surplus with respect to the torque required to drive the vehicle, and the surplus torque is regenerated by motor generator MG2. Alternatively, when the torque of the drive shaft is insufficient with only the engine direct torque Tor, the motor generator MG2 is naturally driven by the power running, and the drive torque is appropriately assisted by the MG2 torque Tm.

  Apart from that, ECU 100 continuously performs SOC feedback control for maintaining the SOC of battery 12 at target value SOCtag. The ECU 100 controls the motor so that the SOC of the battery 12 is maintained at a target value (for example, an appropriate value set in advance) of, for example, about 70% to 80%, regardless of the continuously variable transmission mode or the fixed transmission mode. The power regeneration amounts of the generator MG1 and the motor generator MG2 are controlled. For example, when the SOC is lower than the target value, the power regeneration amount is relatively large, and when the SOC is higher than the target value, the amount of power taken out from the battery 12 is larger. The operating states of the engine 200, MG1, and MG2 are controlled so as to increase.

<Details of rattling noise suppression control>
Here, since the power split mechanism 300 is a mechanical gear mechanism, each gear that is a rotating element has a backlash or other backlash in its rotational direction. Such play can, on the one hand, facilitate the smooth operation of the rotating element, but on the other hand, causes a so-called rattling noise.

  More specifically, the power split mechanism 300 is connected to the engine 200 that is a vibration source via the input shaft 400, and physical vibration that uses the engine 200 as a vibration source is divided into the power split via the input shaft 400. It is transmitted to each rotating element of the mechanism 300. Here, if the torque which can suppress the physical vibration which concerns on each rotation element is acting, the said physical vibration will not generate a rattling sound. Therefore, the sun gear S1 corresponding to the motor generator MG1 that basically gives the reaction torque to the engine 200 is unlikely to be a source of this kind of rattling noise.

  However, the motor generator MG2, which is connected to the drive shaft and maintains relatively independent control, for example, in an extreme case, in an operating condition in which the driver required torque can be provided only by the direct torque Ter that is the direct achievement of the engine torque Te. It is possible to adopt a relatively small power regeneration state for non-operating state or driving of auxiliary machinery. As described above, when the MG2 torque Tm is in the vicinity of zero torque, for example, the physical vibration using the engine 200 as a vibration source may cause the ring gear R1 to vibrate within the range of the backlash and generate a rattling sound. Such rattling noise is a factor that reduces the drivability of the hybrid vehicle 1. Therefore, the hybrid vehicle 1 has a configuration in which a decrease in drivability due to the rattling noise is suppressed by the rattling noise suppression control executed by the ECU 100.

  Here, the details of the rattling noise suppression control will be described with reference to FIG. FIG. 4 is a flowchart of the rattling noise suppression control.

  In FIG. 4, the ECU 100 determines whether or not a gear rattling sound suppression process described later is being executed (step S <b> 101).

  When the rattling noise suppression process is being executed (step S101: YES), the ECU 100 continues the rattling noise suppression process (step S200).

  When the rattling noise suppression process is executed, the ECU 100 determines whether or not the shift start flag is off (step S110). Here, the shift start flag is a flag that is turned on when the shift mode is requested to be switched by the lock mechanism 500 (the timing before the shift mode is actually switched). Is a flag to be controlled.

  When the shift start flag is off (step S110: YES), the ECU 100 determines whether or not the shift mode is being switched (step S111). If the shift mode is not being switched (step S111: YES), the ECU 100 returns the process to step S101.

  On the other hand, when the shift start flag is ON (step S110: NO) or when the shift mode is being switched (step S111: NO), the ECU 100 starts or continues switching the shift mode (step S112), The start flag is set to OFF (step 113), and the process returns to step S101.

  In step S101, when the rattling noise suppression process is not in progress (step S101: NO), the ECU 100 determines whether or not the MG2 torque Tm straddles the avoidance region (step S102). The avoidance region is a rattling noise generation region in the vicinity of zero torque that spans both the positive and negative torque regions centered on zero torque, and is experimentally determined in advance. If the MG2 torque Tm does not straddle the avoidance region (step S102: NO), the need for countermeasures against rattling noise does not occur, and the process returns to step S101.

  When the MG2 torque Tm crosses the avoidance area (step S102: YES), the ECU 100 determines whether or not the current speed change mode is the fixed speed change mode (step S103). When the hybrid vehicle 1 is traveling in the fixed speed change mode (step S102: YES), the ECU 100 determines the SOC (according to the present invention) indicating the state of charge of the battery 12 from the SOC sensor (not shown) attached to the battery 12. It is an example of “a state quantity corresponding to a storage state”, and a fully discharged state is quantified as 0 (%) and a fully charged state is 100 (%)), and the obtained SOC is a lower limit value. It is determined whether or not it is within a reference range defined as a range between SOCtag−α and upper limit SOCtag + α (step S104). Here, the SOC tag is a reference value of the SOC, for example, a value of about 70 to 80 (%). However, the reference value SOCtag may be determined in any way.

  Α that defines the reference range is a value that correlates with the target MG2 torque Tmtag, which is the target value of the MG2 torque Tm, and the target MG2 torque Tmtag for maintaining the SOC of the battery 12 at the reference value SOCtag is outside the avoidance region. This is a threshold value that defines an avoidance area that is necessary to be set in the torque area. When the acquired SOC is not within the reference range (step S104: NO), the ECU 100 shifts the process to step S200 and starts the rattling noise suppression process.

  On the other hand, when the acquired SOC is in the reference range (step S104: YES), the ECU 100 executes a standby process outside the avoidance area (step S105). The waiting process outside the avoidance area is a process of temporarily interrupting the convergence of the MG2 torque Tm to the target MG2 torque Tmtag and maintaining the MG2 torque Tm in the torque area outside the avoidance area. Note that the method of temporarily interrupting the convergence to the target torque not only interrupts the feedback control itself for converging the MG2 torque Tm to the target MG2 torque Tmttag, but also converts the acquired SOC to the SOC reference value SOCtag. It may include provisional measures for setting. That is, in the latter case, the deviation of the SOC feedback control is apparently zero, so that the target MG2 torque Tmtag is maintained at the current value. The effect of the out-of-avoidance-area standby process will be described later.

  In the standby processing outside the avoidance area, the MG2 torque Tm is basically controlled so as not to deviate from the torque area at that time. That is, it is prohibited to maintain the MG2 torque at the torque in the negative or positive torque region across the avoidance region from the current torque region (positive or negative torque region). When the out-of-avoidance-area standby process is executed, the process proceeds to step S112, the current shift mode (that is, the fixed shift mode in this case) is continued, and the process returns to step S101 via step S113.

  In step S103, when the current shift mode is the continuously variable transmission mode (step S103: NO), ECU 100 determines whether or not the shift mode is being switched (step S106).

  When the shift mode is being switched (step S106: YES), the ECU 100 determines whether or not the obtained SOC of the battery 12 is larger than the threshold value β (step S107). Note that the threshold value β is a value that is experimentally determined so that the decrease in the SOC is within the allowable range even if the MG2 torque Tm crossing over the avoidance region is prohibited during the shift mode switching period. When the SOC of the battery 12 is equal to or less than the threshold value β (step S106: NO), the ECU 100 starts a rattling noise suppression process (step S200). If the SOC of the battery 12 is greater than the threshold value β (step S107: YES), the ECU 100 continues to switch the shift mode (step S112). At this time, the MG2 torque Tm is maintained at the value at that time.

  On the other hand, when the hybrid vehicle 1 is traveling in the continuously variable transmission mode and is not switching the transmission mode in step S106 (step S106: NO), the ECU 100 determines whether or not the shift start flag is on (step S106). Step S108). If the shift start flag is off (step S108: NO), the process proceeds to step S200, and the rattling noise suppression process is started.

  Here, when the shift start flag is ON (step S108: YES), that is, when a shift request to the fixed shift mode occurs during traveling in the continuously variable transmission mode, the ECU 100 acquires the SOC of the acquired battery 12. Is less than the threshold value γ (γ> β) (step S109). The threshold value γ according to step S109 is an example of the “predetermined reference value” according to the present invention, which is used for comparison with the state quantity corresponding to the storage state of the storage unit, and the shift mode switching and the MG2 torque Tm It is a value that defines the priority order between the avoidance areas. The threshold value γ is an SOC that can prohibit the avoidance region straddling of the MG2 torque Tm over the entire shift mode switching period, and the previous threshold value β is the SOC that can similarly prohibit the avoidance region straddling during the shift mode switching period. It is. Therefore, the threshold value γ is larger than the threshold value β.

  When the acquired SOC is greater than or equal to the threshold value γ (step S109: NO), the ECU 100 executes the out-of-avoidance-area standby process (step S105), and when the acquired SOC is less than the threshold value γ (step S105). S109: YES), the rattle noise suppression process is executed (step S200).

  Here, in the former case, the shift mode is switched prior to crossing the avoidance region of the MG2 torque Tm in step S112, then step S101 becomes NO, step S102 becomes YES, step S103 becomes YES, and step S104. Becomes NO, and the rattle noise suppression processing is executed in step S200. That is, after the shift mode is switched, the MG2 torque Tm starts to converge toward the original target value. On the other hand, in the latter case, the avoidance region straddling of the MG2 torque Tm is performed prior to the shift mode switching in step S200, and then step S110 is NO, and thus the shift mode switching is started in step S112.

  The rattling noise suppression control is executed as described above. In addition, the rattling noise suppression control according to FIG. 4 is performed in the shift mode from the continuously variable mode to the fixed shift mode as the shift mode switching by switching the avoidance region from the positive torque region as the avoidance region straddling of the MG2 torque Tm. Although the flow assumes each switching, it is needless to say that the rattling noise suppression control can be performed based on the same purpose with respect to the other shift mode switching or the avoidance region crossing direction. For example, when the avoidance region straddling from the negative torque region to the positive torque region is assumed, the value corresponding to the threshold value γ in step S109 may be different from the processing corresponding to the determination result. More specifically, in the negative torque region, that is, the regeneration region, when the SOC of the battery 12 is high (step S109 branches to the NO side), the SOC of the battery 12 exceeds the allowable value during the shift mode switching period. Since there is a possibility that the avoidance region straddling by the rattling noise suppression process is executed prior to the shift mode switching, and the SOC of the battery 12 is low (step S109 branches to YES side), during the shift mode switching period In addition, since no problem arises when the SOC of the battery 12 increases, the shift mode may be switched prior to straddling the avoidance region by the rattling noise suppression processing.

  Next, details of the rattling noise suppression processing will be described with reference to FIG. FIG. 5 is a flowchart of the rattling noise suppression process.

  In FIG. 5, the ECU 100 determines whether the avoidance torque is positive or negative (step S201). The avoidance torque is a torque to be output during a period in which the MG2 torque avoidance region crossing is avoided, and the value of the MG2 torque Tm at that time is usually adopted. When the sign of the avoidance torque is determined, subsequently, the level of the SOC for generating the avoidance torque is determined (step S202). That is, it is determined on which side the provisional target value of the SOC feedback control is present with respect to the original reference value SOCtag. The provisional target value is the SOC of the battery 12 at that time.

  When these determinations are completed, ECU 100 changes the target value of the SOC feedback control from the original target value SOCtag to a provisional target value, and temporarily maintains the deviation of the SOC feedback control to be substantially zero. The SOC feedback control is stopped (step S203).

  Next, the ECU 100 calculates a virtual target torque Tmtgvtl, which is a virtual target value of the MG2 torque Tm (step S204). Here, the virtual target torque Tmtgvtl is the original value of the MG2 torque Tm that is set according to the deviation (that is, the reference deviation) between the original target value SOCtag and the SOC of the battery 12 when the SOC feedback control is resumed. Is the target value. When the virtual target torque Tmtgvtl is calculated, the ECU 100 further calculates a virtual residence time T_Tmtgvtl (step S205).

  Here, the virtual residence time T_Tmtgvtl is the time required for the MG2 torque Tm to pass through the avoidance region in order to converge the MG2 torque Tm to the virtual target torque Tmtgvtl obtained in step S204, that is, according to the present invention. It is an example of “stretching time”. This virtual dwell time T_Tmtgvtl is substantially infinite if the virtual target torque Tmtgvtl is within the avoidance region, and if it is in the torque region outside the avoidance region, the virtual staying time T_Tmtgvtl is farther away from a value that defines the boundary of the avoidance region. As the deviation between the avoidance torque and the virtual target torque Tmtgvtl increases, the deviation becomes shorter. Further, the virtual target torque Tmtgvtl has a larger deviation from the avoidance torque because the SOC deviates from the original reference value SOCtag (that is, the reference deviation increases) as the period during which the MG2 torque is maintained at the avoidance torque is longer. Change direction.

  The ECU 100 determines whether or not the virtual residence time T_Tmtgvtl is less than a predetermined threshold T_Tmtgvtlth (step S206). While the virtual residence time T_Tmtgvtl is equal to or greater than the threshold (step S206: NO), the processing from step S203 to step S206 is repeated. Note that the threshold value T_Tmtgvtl is an adaptive value that is experimentally determined in advance so that the rattling noise that occurs when straddling the avoidance region does not deteriorate the drivability in practice.

  If virtual residence time T_Tmtgvtl is less than threshold value T_Tmtgvtl (step S206: YES), ECU 100 resumes the SOC feedback control (step S207). The rattling noise suppression process is executed in this way.

  The rattling noise suppression process may take a mode other than that shown in FIG. Here, with reference to FIG. 6, another aspect of the rattling noise suppression process will be described. FIG. 6 is a flowchart of another rattling noise suppression process. In the figure, the same reference numerals are assigned to the same parts as those in FIG. 5, and the description thereof is omitted as appropriate.

  In FIG. 6, the ECU 100 determines whether or not the absolute value of the virtual target torque Tmtgvtl calculated in step S204 is larger than a threshold value Tmtgvtlth (step S208). Here, the threshold value Tmtgvtl is a value that defines the upper and lower limit values of the avoidance region (when the avoidance region is equally set in both the positive and negative torque regions).

  If the absolute value of the virtual target torque Tmtgvtl is equal to or smaller than the threshold value Tmtgvtl (step S208: NO), that is, if the virtual target torque Tmtgvtl is a torque within the avoidance region, the ECU 100 repeats steps S203, S204, and S208. If the absolute value of the virtual target torque Tmtgvtl is larger than the threshold value Tmtgvtl (step S208: YES), that is, if the virtual target torque Tmtgvtl is a torque outside the avoidance region, the changing speed of the MG2 torque Tm is The speed is set higher than the speed according to the normal control standard (step S209).

  The ECU 100 controls to maintain the sum of the engine direct torque Ter and the MG2 torque Tm at the driver request torque, so that the change speed of the MG2 torque Tm cooperates with the change speed of the engine torque Te. Be controlled. On the other hand, the engine torque Te depends on the torque of the motor generator MG1 that applies the reaction force torque. Therefore, after all, the change speed control of the MG2 torque Tm is substantially equivalent to the change speed control of the MG1 torque Tg. It is.

  Supplementally, at the normal time when there is no request for such a rattling noise suppression, the high-speed side change speed is not adopted (in this case, the time required to cross the avoidance region is the reference time). This is because high-speed control of torque requires a large control load in that fine control accuracy is required and is likely to appear uncomfortable for the driver. In other words, unless there is a purpose such as suppression of rattling noise (the above-mentioned uncomfortable feeling does not affect drivability as much as noise due to rattling noise), there is no practical merit in adopting high-speed control.

  When the change speed of the MG2 torque Tm is corrected to the high speed side in step S209 and the MG2 torque deviates from the avoidance region, the process proceeds to step S207, and the SOC feedback control is resumed. Even if it does in this way, it is possible to suppress a rattling sound suitably.

<Effects of rattling noise suppression control>
Next, the effect of the rattling noise suppression control will be described. First, the effect of the rattling noise suppression process will be described with reference to FIG. FIG. 7 is a schematic diagram illustrating the MG2 torque Tm and the engine required output Pne over time in the execution process of the rattling noise suppression process.

  In FIG. 7, the upper stage is the time characteristic of the MG2 torque Tm, and the lower stage is the time characteristic of the engine required output Pne. FIG. 7 is a time transition during normal traveling according to the continuously variable transmission mode, not the shift mode switching period. Since it is determined whether or not the MG2 torque crossing over the avoidance region is caused by the magnitude of the MG2 torque Tm, for example, in the operation region in which most of the driver request torque can be covered only by the engine direct delivery torque Ter, the required value of the MG2 torque Tm is It is not necessarily expensive.

  In FIG. 7, PRF_Ref1 (see the broken line) is a characteristic similar to the comparative example for clarifying the effect of the present embodiment, and is a characteristic in a case where no countermeasures for avoiding rattling noise are taken. PRF_TmA (refer to practice) is a characteristic when a measure corresponding to step S200 of the rattling noise suppression control according to the present embodiment is taken.

  Here, it is assumed that the target value of the MG2 torque Tm is switched from Tmtg1 to Tmtg2 before time T1. In this case, in the comparative example, the MG2 torque Tm starts to decrease at time T1, reaches the avoidance region (the hatching region defined by Tmth and -Tmth in the drawing) at time T2, and sets the avoidance region at time T3. Finally, it converges to the target MG2 torque Tmtg2 at time T6.

  On the other hand, when the rattling noise suppression process according to the present embodiment is executed, the MG2 torque Tm continues to maintain the current value even after the time T1 has passed. At this time, in order to maintain the driver request torque, the engine request output Pne is temporarily set on the side lower than the original value (see PRF_PneA in the drawing). When the MG2 torque Tm is maintained at a torque deviating from the original target torque (regeneration region side torque) in this way, the SOC of the battery 12 begins to deviate from the reference value SOCtag, which is the original target value, and the deviation is large. Become.

  Following such a process, when the SOC feedback control is resumed at time T4, for example, when step S206 of FIG. 5 described above is satisfied, the provisional target torque becomes larger than Tmtg2 due to the expanded SOC deviation. Since the absolute value is set on the larger side, the MG2 torque Tm changes more rapidly than the comparative example, and finally converges to the original target torque Tmtg2.

  Here, when the straddling time required to pass through the avoidance region is compared between the comparative example and the present embodiment, the straddling time is a time corresponding to “T3-T2” according to the comparative example. According to this, the time corresponding to “T5-T4” is obtained. At this time, it is clear from the figure that the latter is smaller. That is, when the measure according to the present embodiment is taken, the straddling time is drastically shortened, and the generation of rattling noise is effectively suppressed.

  Next, the effect of the rattling noise suppression process will be further described with reference to FIG. FIG. 8 is a schematic diagram illustrating another time transition of the MG2 torque Tm and the engine required output Pne in the process of executing the rattling noise suppression process. In the figure, the same reference numerals are assigned to the same parts as those in FIG. 7, and the description thereof is omitted as appropriate.

  FIG. 8 exemplifies time characteristics of the MG2 torque Tm and the engine required output Pne mainly before and after switching of the shift mode or during the shift mode switching, such as step S107 or S109 of FIG.

  Here, it is assumed that the switching of the shift mode is started at time T10 (that is, the shift start flag itself has been turned on before that, and the time delay for performing the determination related to step S109 is sufficiently secured. ). Here, the characteristic when the rattling noise suppression processing according to step S200 is executed during the shift mode switching period (that is, corresponding to the case where step S107 is NO) is PRF_TmA (see the solid line), The characteristic when the rattling noise suppression processing is executed prior to the mode switching (that is, corresponding to the case where step S109 is NO) is PRF_TmB (see the broken line), and the rattling noise suppression is performed after the shift mode is switched. The characteristic when the process is executed (that is, corresponding to the case where step S109 is YES) is PRF_TmC (see the chain line). Further, the time characteristics of the engine required output Pne corresponding to each are expressed as PRF_PnA (solid line), PRF_PnB (broken line), and PRF_PnC (chain line) in the lower stage, respectively.

  As shown in the figure, even if the rattling noise suppression processing is executed at any timing, the time required to cross the avoidance region is shortened compared to the comparative example, and the drivability degradation due to the rattling noise is suitably It is suppressed. Here, in particular, in the present embodiment, basically, before the start of switching of the shift mode, it is determined which of the shift mode switching and the MG2 torque Tm straddle avoidance region is executed first. When the shift mode is switched, the MG2 torque Tm changes as PRF_TmC or PRF_TmB.

  That is, according to the rattle noise suppression control according to the present embodiment, the shift mode switching period and the period in which the MG2 torque crosses the avoidance region do not overlap, and an increase in noise due to the overlap is avoided. The Therefore, a decrease in drivability is preferably suppressed. However, even if there is a need to cross the avoidance area during switching of the shift mode due to a sudden disturbance or the like, since the straddling time is shortened as in PRF_TmA, the shift of the shift mode and the straddle of the avoidance area overlap. As a result, drivability is minimized.

  Next, another effect of the rattling noise suppression control according to the present invention will be described with reference to FIG. FIG. 9 is a schematic view exemplifying the one-time transition of the battery SOC and the MG2 torque Tm in the execution process of the rattling noise suppression control. FIG. 9 shows a time transition corresponding to the process according to step S104 of FIG.

  In FIG. 9, the target value of the MG2 torque for maintaining the SOC reference value SOCtag within the reference range (the range defined by SOCtag + α and SOCtag−α) is an avoidance region (hatching region between Tmth and −Tmth in the drawing). Reference) is shown. In this case, according to the rattling noise suppression control according to the present embodiment, the MG2 torque Tm gradually varies between the positive torque region and the negative torque region sandwiching the avoidance region. Further, in the process of this variation, when the MG2 torque Tm crosses the avoidance region, the straddling time is shortened by the same rattling noise suppression processing as described above. Therefore, it is possible to suppress the occurrence of rattling noise as much as possible.

Supplementally, when no countermeasures similar to the rattling noise suppression control according to the present invention are taken, the MG2 torque Tm spanning the avoidance region (that is, the reference time) is the entire time region shown in the figure. On the other hand, when charging / discharging of the battery 12 is gently repeated as shown by the solid line in the figure, the straddling time is limited to a finite time range in which the MG2 torque Tm stays in the avoidance region. Therefore, the crossing time is suitably shortened, and drivability is remarkably improved. In addition, as shown in the figure, the straddling time can be shortened more effectively by shortening the straddling time related to the rattling noise suppression processing.
Second Embodiment
The aspect of the power transmission mechanism according to the present invention is not limited to that illustrated in FIG. Here, with reference to FIG. 10, the structure of the hybrid drive device 20 which concerns on 2nd Embodiment of this invention is demonstrated. FIG. 10 is a schematic configuration diagram conceptually showing the configuration of the hybrid drive apparatus 20. In the figure, the same reference numerals are assigned to the same portions as those in FIG. 2, and the description thereof is omitted as appropriate.

  In FIG. 10, the hybrid drive device 20 is different from the hybrid drive device 10 in that it includes a power split mechanism 800 and an MG2 speed change mechanism 900.

  The power split mechanism 800 is a composite planetary gear mechanism that is an example of a “power transmission mechanism” according to the present invention, in which a first planetary gear mechanism and a second planetary gear mechanism are combined.

  The first planetary gear mechanism is arranged between a sun gear S3 provided in the center, a ring gear R3 provided concentrically on the outer periphery of the sun gear S3, and between the sun gear S3 and the ring gear R3, and the outer periphery of the sun gear S3. And a plurality of pinion gears (not shown) that revolve while rotating, and a carrier C3 that supports the rotation shaft of each pinion gear.

  The second planetary gear mechanism is disposed between the sun gear S4 provided at the center, the ring gear R4 provided concentrically on the outer periphery of the sun gear S4, and the sun gear S4 and the ring gear R4. A plurality of pinion gears (not shown) that revolve while rotating on the outer periphery, and a carrier C4 that supports the rotation shaft of each pinion gear. Here, the ring gear R4 and the carrier C4 of the second planetary gear mechanism are directly connected to the carrier C3 and the ring gear R3 of the first planetary gear mechanism, respectively.

  On the other hand, the sun gear S4 of the second planetary gear mechanism is connected to the lock mechanism 500, and the state thereof can be selectively switched between a locked state and an unlocked state by the action of the lock mechanism 500. .

  Here, the sun gear S3 is coupled to the rotor of the motor generator MG1 so as to share the rotation axis thereof, and the rotation speed is equivalent to the MG1 rotation speed Nmg1 that is the rotation speed of the MG1. Ring gear R3 is connected to the rotor of motor generator MG2 via drive shaft 1000 and MG2 speed change mechanism 700, and the rotational speed thereof is equivalent to output rotational speed Nout described above. Further, the carrier C3 is connected to an input shaft connected to the crankshaft of the engine 200, and the rotational speed thereof is equivalent to the engine rotational speed NE of the engine 200.

  The MG2 speed change mechanism 700 is a stepped speed change mechanism interposed between the drive shaft 1000 and the motor generator MG2. MG2 speed change mechanism 700 can change the rotational speed ratio between drive shaft 1000 and motor generator MG2 in accordance with the gear ratio of the speed selected at that time.

  According to such a configuration, when the sun gear S4 is in the locked state (in a so-called O / D lock), the fixed transmission mode is selected as the transmission mode, and the sun gear S4 is in the unlocked state. The continuously variable transmission mode is selected as the transmission mode.

Even for the hybrid drive device 20 having such a configuration, the practical benefit related to the above-described rattling noise suppression control is ensured.
<Third Embodiment>
The aspect of the power transmission mechanism according to the present invention is not limited to that illustrated in FIGS. 2 and 10. Here, with reference to FIG. 11, the structure of the hybrid drive device 30 which concerns on 3rd Embodiment of this invention is demonstrated. FIG. 11 is a schematic configuration diagram conceptually showing the configuration of the hybrid drive device 30. In the figure, the same parts as those in FIG. 10 are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  In FIG. 11, the hybrid drive device 30 is different from the hybrid drive device 20 in that it includes a power split mechanism 1100.

  The power split mechanism 1100 is disposed between the sun gear S5 provided at the center, the ring gear R5 provided concentrically on the outer periphery of the sun gear S5, and the sun gear S5 and the ring gear R5. A plurality of pinion gears (not shown) that revolve while rotating, and a carrier C5 that supports the rotation shaft of each pinion gear.

  Here, the sun gear S5, the ring gear R5, and the carrier C5 are connected to the MG1, MG2, and the engine 200, respectively. If the sun gear S5 is in an unlocked state due to the differential action of these gears, continuously variable speed change is possible. The mode is preferably realized. On the other hand, when the sun gear S5 is in the locked state, a lock form called MG1 lock is realized as in the hybrid drive device 10, and the fixed speed change mode is realized.

  Even for the hybrid drive device 20 having such a configuration, the practical benefit related to the above-described rattling noise suppression control is ensured.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and control of a hybrid vehicle involving such a change. The apparatus is also included in the technical scope of the present invention.

  The present invention can be applied to a hybrid vehicle capable of switching the transmission mode between the continuously variable transmission mode and the fixed transmission mode.

  DESCRIPTION OF SYMBOLS 1 ... Hybrid vehicle, 10 ... Hybrid drive device, 100 ... ECU, 200 ... Engine, 300 ... Power split mechanism, 400 ... Input shaft, 500 ... Lock mechanism, 600 ... MG2 reduction mechanism, 700 ... Deceleration mechanism, 800 ... Power split Mechanism: 900 ... MG2 transmission mechanism, 1000 ... drive shaft, 1100 ... power split mechanism.

Claims (6)

An internal combustion engine;
Rotating electrical machinery,
Power storage means capable of supplying electric power to the rotating electrical machine and capable of being charged by regenerative power of the rotating electrical machine;
A power transmission mechanism comprising a plurality of rotating elements each having play in the rotational direction, and configured to transmit torque between a drive shaft coupled to an axle and the internal combustion engine and the rotating electrical machine;
Lock means capable of selectively switching the state of one of the plurality of rotating elements between a non-rotatable locked state and a rotatable non-locking state;
Corresponding to the unlocked state, a continuously variable transmission mode in which a transmission gear ratio between the rotational speed of the internal combustion engine and the rotational speed of the drive shaft is continuously variable, and corresponding to the locked state, the transmission gear ratio An apparatus for controlling a hybrid vehicle configured to be capable of switching a shift mode between a fixed shift mode and a fixed shift mode,
An avoidance region set to cause the power transmission mechanism to generate rattling noise in the process in which the input / output torque of the rotating electrical machine with respect to the drive shaft converges to the target torque during the shift mode switching period. A determination means for determining whether or not to straddle;
Control means for controlling the input / output torque so that the shift mode switching period and the input / output torque cross the avoidance area do not overlap when it is determined that the input / output torque straddles the avoidance area A control apparatus for a hybrid vehicle, comprising: The control means performs cooperative control of the engine torque supplied from the internal combustion engine and the input / output torque so that the driver required torque required for the drive shaft is maintained. The hybrid vehicle control apparatus described. The output torque is performed to shorten the crossover time as the time required to straddle the avoidance region, takes the crossover time, the output torque when the shortening is not made that straddle the avoidance area The hybrid vehicle control device according to claim 1, further comprising a shortening unit that shortens the reference time as a time. The target torque is determined according to the reference deviation such that the magnitude of the standard deviation, which is the deviation between the state quantity corresponding to the storage state of the power storage means and the reference value of the state quantity, corresponds to the magnitude of the target torque, respectively. Set,
The shortening means temporarily stops the setting of the target torque according to the reference deviation, and increases the reference deviation by maintaining the input / output torque in a torque region outside the avoidance region, and The control apparatus for a hybrid vehicle according to claim 3, wherein the straddling time is shortened by restarting the setting of a target torque according to the reference deviation after the reference deviation is increased. In the case where the input / output torque crosses the avoidance region from the positive torque region, the control means,
The input / output torque is controlled so as to cross the avoidance area after the shift mode is switched when a state quantity corresponding to a storage state of the power storage unit is higher than a predetermined reference value. The control apparatus of the hybrid vehicle as described in any one of Claim 1 to 4. In the case where the input / output torque crosses the avoidance region from the positive torque region, the control unit precedes the shift mode switching when the state quantity corresponding to the storage state of the storage unit is lower than a predetermined reference value. The hybrid vehicle control device according to claim 1, wherein the input / output torque is controlled so as to straddle the avoidance region.